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small cleanup in CREDITS #12
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I believe pull requests like this are not used. https://github.com/torvalds/linux/blob/master/Documentation/HOWTO I recommend reading that. |
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Thanks Gunni! Now that I have read my way through the documentation, three small questions before I close this:
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This is considered a trivial patch. Please consult |
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Well, according to https://github.com/torvalds/linux/blob/master/Documentation/SubmittingPatches#L200 you should mail Jiri Kosina trivial@kernel.org. https://github.com/torvalds/linux/blob/master/MAINTAINERS#L6515 However since kernel.org is down i can not say where this should be sent, maybe use vger as a replacement and note that you're mailing there because the correct mail is down. EDIT: yeah or use the mail sc68cal submitted: Jiri Kosina jkosina@suse.cz. |
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Thanks a lot! I'll email my patch to Jiri Kosina. |
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You also need to amend your commit message to add a sign off line. You need that in the commit message or your patch will not be accepted. Check the docs for more info |
When the cgroup base was allocated with kmalloc, it was necessary to annotate the variable with kmemleak_not_leak(). But because it has recently been changed to be allocated with alloc_page() (which skips kmemleak checks) causes a warning on boot up. I was triggering this output: allocated 8388608 bytes of page_cgroup please try 'cgroup_disable=memory' option if you don't want memory cgroups kmemleak: Trying to color unknown object at 0xf5840000 as Grey Pid: 0, comm: swapper Not tainted 3.0.0-test #12 Call Trace: [<c17e34e6>] ? printk+0x1d/0x1f^M [<c10e2941>] paint_ptr+0x4f/0x78 [<c178ab57>] kmemleak_not_leak+0x58/0x7d [<c108ae9f>] ? __rcu_read_unlock+0x9/0x7d [<c1cdb462>] kmemleak_init+0x19d/0x1e9 [<c1cbf771>] start_kernel+0x346/0x3ec [<c1cbf1b4>] ? loglevel+0x18/0x18 [<c1cbf0aa>] i386_start_kernel+0xaa/0xb0 After a bit of debugging I tracked the object 0xf840000 (and others) down to the cgroup code. The change from allocating base with kmalloc to alloc_page() has the base not calling kmemleak_alloc() which adds the pointer to the object_tree_root, but kmemleak_not_leak() adds it to the crt_early_log[] table. On kmemleak_init(), the entry is found in the early_log[] but not the object_tree_root, and this error message is displayed. If alloc_page() fails then it defaults back to vmalloc() which still uses the kmemleak_alloc() which makes us still need the kmemleak_not_leak() call. The solution is to call the kmemleak_alloc() directly if the alloc_page() succeeds. Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Ingo Molnar <mingo@elte.hu> wrote: > The patch below addresses these concerns, serializes the output, tidies up the > printout, resulting in this new output: There's one bug remaining that my patch does not address: the vCPUs are not printed in order: # vCPU #0's dump: # vCPU #2's dump: # vCPU torvalds#24's dump: # vCPU #5's dump: # vCPU torvalds#39's dump: # vCPU torvalds#38's dump: # vCPU torvalds#51's dump: # vCPU torvalds#11's dump: # vCPU torvalds#10's dump: # vCPU torvalds#12's dump: This is undesirable as the order of printout is highly random, so successive dumps are difficult to compare. The patch below serializes the signalling itself. (this is on top of the previous patch) The patch also tweaks the vCPU printout line a bit so that it does not start with '#', which is discarded if such messages are pasted into Git commit messages. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Pekka Enberg <penberg@kernel.org>
If the pte mapping in generic_perform_write() is unmapped between iov_iter_fault_in_readable() and iov_iter_copy_from_user_atomic(), the "copied" parameter to ->end_write can be zero. ext4 couldn't cope with it with delayed allocations enabled. This skips the i_disksize enlargement logic if copied is zero and no new data was appeneded to the inode. gdb> bt #0 0xffffffff811afe80 in ext4_da_should_update_i_disksize (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x1\ 08000, len=0x1000, copied=0x0, page=0xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2467 #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 #2 0xffffffff810d97f1 in generic_perform_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value o\ ptimized out>, pos=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2440 #3 generic_file_buffered_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value optimized out>, p\ os=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2482 #4 0xffffffff810db5d1 in __generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, ppos=0\ xffff88001e26be40) at mm/filemap.c:2600 #5 0xffffffff810db853 in generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=<value optimi\ zed out>, pos=<value optimized out>) at mm/filemap.c:2632 #6 0xffffffff811a71aa in ext4_file_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, pos=0x108000) a\ t fs/ext4/file.c:136 #7 0xffffffff811375aa in do_sync_write (filp=0xffff88003f606a80, buf=<value optimized out>, len=<value optimized out>, \ ppos=0xffff88001e26bf48) at fs/read_write.c:406 #8 0xffffffff81137e56 in vfs_write (file=0xffff88003f606a80, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x4\ 000, pos=0xffff88001e26bf48) at fs/read_write.c:435 #9 0xffffffff8113816c in sys_write (fd=<value optimized out>, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x\ 4000) at fs/read_write.c:487 #10 <signal handler called> #11 0x00007f120077a390 in __brk_reservation_fn_dmi_alloc__ () #12 0x0000000000000000 in ?? () gdb> print offset $22 = 0xffffffffffffffff gdb> print idx $23 = 0xffffffff gdb> print inode->i_blkbits $24 = 0xc gdb> up #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 2512 if (ext4_da_should_update_i_disksize(page, end)) { gdb> print start $25 = 0x0 gdb> print end $26 = 0xffffffffffffffff gdb> print pos $27 = 0x108000 gdb> print new_i_size $28 = 0x108000 gdb> print ((struct ext4_inode_info *)((char *)inode-((int)(&((struct ext4_inode_info *)0)->vfs_inode))))->i_disksize $29 = 0xd9000 gdb> down 2467 for (i = 0; i < idx; i++) gdb> print i $30 = 0xd44acbee This is 100% reproducible with some autonuma development code tuned in a very aggressive manner (not normal way even for knumad) which does "exotic" changes to the ptes. It wouldn't normally trigger but I don't see why it can't happen normally if the page is added to swap cache in between the two faults leading to "copied" being zero (which then hangs in ext4). So it should be fixed. Especially possible with lumpy reclaim (albeit disabled if compaction is enabled) as that would ignore the young bits in the ptes. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@kernel.org
Overly indented code should be refactored.
Suggest refactoring excessive indentation of of
if/else/for/do/while/switch statements.
For example:
$ cat t.c
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char **argv)
{
if (1)
if (2)
if (3)
if (4)
if (5)
if (6)
if (7)
if (8)
;
return 0;
}
$ ./scripts/checkpatch.pl -f t.c
WARNING: Too many leading tabs - consider code refactoring
#12: FILE: t.c:12:
+ if (6)
WARNING: Too many leading tabs - consider code refactoring
#13: FILE: t.c:13:
+ if (7)
WARNING: Too many leading tabs - consider code refactoring
#14: FILE: t.c:14:
+ if (8)
total: 0 errors, 3 warnings, 17 lines checked
t.c has style problems, please review.
If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the netdev is already in NETREG_UNREGISTERING/_UNREGISTERED state, do not update the real num tx queues. netdev_queue_update_kobjects() is already called via remove_queue_kobjects() at NETREG_UNREGISTERING time. So, when upper layer driver, e.g., FCoE protocol stack is monitoring the netdev event of NETDEV_UNREGISTER and calls back to LLD ndo_fcoe_disable() to remove extra queues allocated for FCoE, the associated txq sysfs kobjects are already removed, and trying to update the real num queues would cause something like below: ... PID: 25138 TASK: ffff88021e64c440 CPU: 3 COMMAND: "kworker/3:3" #0 [ffff88021f007760] machine_kexec at ffffffff810226d9 #1 [ffff88021f0077d0] crash_kexec at ffffffff81089d2d #2 [ffff88021f0078a0] oops_end at ffffffff813bca78 #3 [ffff88021f0078d0] no_context at ffffffff81029e72 #4 [ffff88021f007920] __bad_area_nosemaphore at ffffffff8102a155 #5 [ffff88021f0079f0] bad_area_nosemaphore at ffffffff8102a23e torvalds#6 [ffff88021f007a00] do_page_fault at ffffffff813bf32e torvalds#7 [ffff88021f007b10] page_fault at ffffffff813bc045 [exception RIP: sysfs_find_dirent+17] RIP: ffffffff81178611 RSP: ffff88021f007bc0 RFLAGS: 00010246 RAX: ffff88021e64c440 RBX: ffffffff8156cc63 RCX: 0000000000000004 RDX: ffffffff8156cc63 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88021f007be0 R8: 0000000000000004 R9: 0000000000000008 R10: ffffffff816fed00 R11: 0000000000000004 R12: 0000000000000000 R13: ffffffff8156cc63 R14: 0000000000000000 R15: ffff8802222a0000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 torvalds#8 [ffff88021f007be8] sysfs_get_dirent at ffffffff81178c07 torvalds#9 [ffff88021f007c18] sysfs_remove_group at ffffffff8117ac27 torvalds#10 [ffff88021f007c48] netdev_queue_update_kobjects at ffffffff813178f9 torvalds#11 [ffff88021f007c88] netif_set_real_num_tx_queues at ffffffff81303e38 torvalds#12 [ffff88021f007cc8] ixgbe_set_num_queues at ffffffffa0249763 [ixgbe] torvalds#13 [ffff88021f007cf8] ixgbe_init_interrupt_scheme at ffffffffa024ea89 [ixgbe] torvalds#14 [ffff88021f007d48] ixgbe_fcoe_disable at ffffffffa0267113 [ixgbe] torvalds#15 [ffff88021f007d68] vlan_dev_fcoe_disable at ffffffffa014fef5 [8021q] torvalds#16 [ffff88021f007d78] fcoe_interface_cleanup at ffffffffa02b7dfd [fcoe] torvalds#17 [ffff88021f007df8] fcoe_destroy_work at ffffffffa02b7f08 [fcoe] torvalds#18 [ffff88021f007e18] process_one_work at ffffffff8105d7ca torvalds#19 [ffff88021f007e68] worker_thread at ffffffff81060513 torvalds#20 [ffff88021f007ee8] kthread at ffffffff810648b6 torvalds#21 [ffff88021f007f48] kernel_thread_helper at ffffffff813c40f4 Signed-off-by: Yi Zou <yi.zou@intel.com> Tested-by: Ross Brattain <ross.b.brattain@intel.com> Tested-by: Stephen Ko <stephen.s.ko@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
If the netdev is already in NETREG_UNREGISTERING/_UNREGISTERED state, do not update the real num tx queues. netdev_queue_update_kobjects() is already called via remove_queue_kobjects() at NETREG_UNREGISTERING time. So, when upper layer driver, e.g., FCoE protocol stack is monitoring the netdev event of NETDEV_UNREGISTER and calls back to LLD ndo_fcoe_disable() to remove extra queues allocated for FCoE, the associated txq sysfs kobjects are already removed, and trying to update the real num queues would cause something like below: ... PID: 25138 TASK: ffff88021e64c440 CPU: 3 COMMAND: "kworker/3:3" #0 [ffff88021f007760] machine_kexec at ffffffff810226d9 #1 [ffff88021f0077d0] crash_kexec at ffffffff81089d2d #2 [ffff88021f0078a0] oops_end at ffffffff813bca78 #3 [ffff88021f0078d0] no_context at ffffffff81029e72 #4 [ffff88021f007920] __bad_area_nosemaphore at ffffffff8102a155 #5 [ffff88021f0079f0] bad_area_nosemaphore at ffffffff8102a23e torvalds#6 [ffff88021f007a00] do_page_fault at ffffffff813bf32e torvalds#7 [ffff88021f007b10] page_fault at ffffffff813bc045 [exception RIP: sysfs_find_dirent+17] RIP: ffffffff81178611 RSP: ffff88021f007bc0 RFLAGS: 00010246 RAX: ffff88021e64c440 RBX: ffffffff8156cc63 RCX: 0000000000000004 RDX: ffffffff8156cc63 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88021f007be0 R8: 0000000000000004 R9: 0000000000000008 R10: ffffffff816fed00 R11: 0000000000000004 R12: 0000000000000000 R13: ffffffff8156cc63 R14: 0000000000000000 R15: ffff8802222a0000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 torvalds#8 [ffff88021f007be8] sysfs_get_dirent at ffffffff81178c07 torvalds#9 [ffff88021f007c18] sysfs_remove_group at ffffffff8117ac27 torvalds#10 [ffff88021f007c48] netdev_queue_update_kobjects at ffffffff813178f9 torvalds#11 [ffff88021f007c88] netif_set_real_num_tx_queues at ffffffff81303e38 torvalds#12 [ffff88021f007cc8] ixgbe_set_num_queues at ffffffffa0249763 [ixgbe] torvalds#13 [ffff88021f007cf8] ixgbe_init_interrupt_scheme at ffffffffa024ea89 [ixgbe] torvalds#14 [ffff88021f007d48] ixgbe_fcoe_disable at ffffffffa0267113 [ixgbe] torvalds#15 [ffff88021f007d68] vlan_dev_fcoe_disable at ffffffffa014fef5 [8021q] torvalds#16 [ffff88021f007d78] fcoe_interface_cleanup at ffffffffa02b7dfd [fcoe] torvalds#17 [ffff88021f007df8] fcoe_destroy_work at ffffffffa02b7f08 [fcoe] torvalds#18 [ffff88021f007e18] process_one_work at ffffffff8105d7ca torvalds#19 [ffff88021f007e68] worker_thread at ffffffff81060513 torvalds#20 [ffff88021f007ee8] kthread at ffffffff810648b6 torvalds#21 [ffff88021f007f48] kernel_thread_helper at ffffffff813c40f4 Signed-off-by: Yi Zou <yi.zou@intel.com> Tested-by: Ross Brattain <ross.b.brattain@intel.com> Tested-by: Stephen Ko <stephen.s.ko@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 torvalds#6 [d72d3cb4] isolate_migratepages at c030b15a torvalds#7 [d72d3d14] zone_watermark_ok at c02d26cb torvalds#8 [d72d3d2c] compact_zone at c030b8d torvalds#9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 torvalds#6 [d72d3cb4] isolate_migratepages at c030b15a torvalds#7 [d72d3d14] zone_watermark_ok at c02d26cb torvalds#8 [d72d3d2c] compact_zone at c030b8d torvalds#9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8d #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8d #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8d #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8d #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8d #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8d #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8d #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8d #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
BugLink: http://bugs.launchpad.net/bugs/907778 commit ea51d13 upstream. If the pte mapping in generic_perform_write() is unmapped between iov_iter_fault_in_readable() and iov_iter_copy_from_user_atomic(), the "copied" parameter to ->end_write can be zero. ext4 couldn't cope with it with delayed allocations enabled. This skips the i_disksize enlargement logic if copied is zero and no new data was appeneded to the inode. gdb> bt #0 0xffffffff811afe80 in ext4_da_should_update_i_disksize (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x1\ 08000, len=0x1000, copied=0x0, page=0xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2467 #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 #2 0xffffffff810d97f1 in generic_perform_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value o\ ptimized out>, pos=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2440 #3 generic_file_buffered_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value optimized out>, p\ os=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2482 #4 0xffffffff810db5d1 in __generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, ppos=0\ xffff88001e26be40) at mm/filemap.c:2600 #5 0xffffffff810db853 in generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=<value optimi\ zed out>, pos=<value optimized out>) at mm/filemap.c:2632 torvalds#6 0xffffffff811a71aa in ext4_file_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, pos=0x108000) a\ t fs/ext4/file.c:136 torvalds#7 0xffffffff811375aa in do_sync_write (filp=0xffff88003f606a80, buf=<value optimized out>, len=<value optimized out>, \ ppos=0xffff88001e26bf48) at fs/read_write.c:406 torvalds#8 0xffffffff81137e56 in vfs_write (file=0xffff88003f606a80, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x4\ 000, pos=0xffff88001e26bf48) at fs/read_write.c:435 torvalds#9 0xffffffff8113816c in sys_write (fd=<value optimized out>, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x\ 4000) at fs/read_write.c:487 torvalds#10 <signal handler called> torvalds#11 0x00007f120077a390 in __brk_reservation_fn_dmi_alloc__ () torvalds#12 0x0000000000000000 in ?? () gdb> print offset $22 = 0xffffffffffffffff gdb> print idx $23 = 0xffffffff gdb> print inode->i_blkbits $24 = 0xc gdb> up #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 2512 if (ext4_da_should_update_i_disksize(page, end)) { gdb> print start $25 = 0x0 gdb> print end $26 = 0xffffffffffffffff gdb> print pos $27 = 0x108000 gdb> print new_i_size $28 = 0x108000 gdb> print ((struct ext4_inode_info *)((char *)inode-((int)(&((struct ext4_inode_info *)0)->vfs_inode))))->i_disksize $29 = 0xd9000 gdb> down 2467 for (i = 0; i < idx; i++) gdb> print i $30 = 0xd44acbee This is 100% reproducible with some autonuma development code tuned in a very aggressive manner (not normal way even for knumad) which does "exotic" changes to the ptes. It wouldn't normally trigger but I don't see why it can't happen normally if the page is added to swap cache in between the two faults leading to "copied" being zero (which then hangs in ext4). So it should be fixed. Especially possible with lumpy reclaim (albeit disabled if compaction is enabled) as that would ignore the young bits in the ptes. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: Brad Figg <brad.figg@canonical.com>
…S block during isolation for migration BugLink: http://bugs.launchpad.net/bugs/931719 commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 torvalds#6 [d72d3cb4] isolate_migratepages at c030b15a torvalds#7 [d72d3d14] zone_watermark_ok at c02d26cb torvalds#8 [d72d3d2c] compact_zone at c030b8d torvalds#9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8d #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8d #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8d #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8d #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 48918ca ] The test starts a workload and then opens events. If the events fail to open, for example because of perf_event_paranoid, the gopipe of the workload is leaked and the file descriptor leak check fails when the test exits. To avoid this cancel the workload when opening the events fails. Before: ``` $ perf test -vv 7 7: PERF_RECORD_* events & perf_sample fields: --- start --- test child forked, pid 1189568 Using CPUID GenuineIntel-6-B7-1 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0xa00000000 (cpu_atom/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 sys_perf_event_open failed, error -13 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0xa00000000 (cpu_atom/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 exclude_kernel 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 3 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0x400000000 (cpu_core/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 sys_perf_event_open failed, error -13 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0x400000000 (cpu_core/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 exclude_kernel 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 3 Attempt to add: software/cpu-clock/ ..after resolving event: software/config=0/ cpu-clock -> software/cpu-clock/ ------------------------------------------------------------ perf_event_attr: type 1 (PERF_TYPE_SOFTWARE) size 136 config 0x9 (PERF_COUNT_SW_DUMMY) sample_type IP|TID|TIME|CPU read_format ID|LOST disabled 1 inherit 1 mmap 1 comm 1 enable_on_exec 1 task 1 sample_id_all 1 mmap2 1 comm_exec 1 ksymbol 1 bpf_event 1 { wakeup_events, wakeup_watermark } 1 ------------------------------------------------------------ sys_perf_event_open: pid 1189569 cpu 0 group_fd -1 flags 0x8 sys_perf_event_open failed, error -13 perf_evlist__open: Permission denied ---- end(-2) ---- Leak of file descriptor 6 that opened: 'pipe:[14200347]' ---- unexpected signal (6) ---- iFailed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon #0 0x565358f6666e in child_test_sig_handler builtin-test.c:311 #1 0x7f29ce849df0 in __restore_rt libc_sigaction.c:0 #2 0x7f29ce89e95c in __pthread_kill_implementation pthread_kill.c:44 #3 0x7f29ce849cc2 in raise raise.c:27 #4 0x7f29ce8324ac in abort abort.c:81 #5 0x565358f662d4 in check_leaks builtin-test.c:226 torvalds#6 0x565358f6682e in run_test_child builtin-test.c:344 torvalds#7 0x565358ef7121 in start_command run-command.c:128 torvalds#8 0x565358f67273 in start_test builtin-test.c:545 torvalds#9 0x565358f6771d in __cmd_test builtin-test.c:647 torvalds#10 0x565358f682bd in cmd_test builtin-test.c:849 torvalds#11 0x565358ee5ded in run_builtin perf.c:349 torvalds#12 0x565358ee6085 in handle_internal_command perf.c:401 torvalds#13 0x565358ee61de in run_argv perf.c:448 torvalds#14 0x565358ee6527 in main perf.c:555 torvalds#15 0x7f29ce833ca8 in __libc_start_call_main libc_start_call_main.h:74 torvalds#16 0x7f29ce833d65 in __libc_start_main@@GLIBC_2.34 libc-start.c:128 torvalds#17 0x565358e391c1 in _start perf[851c1] 7: PERF_RECORD_* events & perf_sample fields : FAILED! ``` After: ``` $ perf test 7 7: PERF_RECORD_* events & perf_sample fields : Skip (permissions) ``` Fixes: 16d00fe ("perf tests: Move test__PERF_RECORD into separate object") Signed-off-by: Ian Rogers <irogers@google.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 48918ca ] The test starts a workload and then opens events. If the events fail to open, for example because of perf_event_paranoid, the gopipe of the workload is leaked and the file descriptor leak check fails when the test exits. To avoid this cancel the workload when opening the events fails. Before: ``` $ perf test -vv 7 7: PERF_RECORD_* events & perf_sample fields: --- start --- test child forked, pid 1189568 Using CPUID GenuineIntel-6-B7-1 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0xa00000000 (cpu_atom/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 sys_perf_event_open failed, error -13 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0xa00000000 (cpu_atom/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 exclude_kernel 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 3 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0x400000000 (cpu_core/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 sys_perf_event_open failed, error -13 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0x400000000 (cpu_core/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 exclude_kernel 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 3 Attempt to add: software/cpu-clock/ ..after resolving event: software/config=0/ cpu-clock -> software/cpu-clock/ ------------------------------------------------------------ perf_event_attr: type 1 (PERF_TYPE_SOFTWARE) size 136 config 0x9 (PERF_COUNT_SW_DUMMY) sample_type IP|TID|TIME|CPU read_format ID|LOST disabled 1 inherit 1 mmap 1 comm 1 enable_on_exec 1 task 1 sample_id_all 1 mmap2 1 comm_exec 1 ksymbol 1 bpf_event 1 { wakeup_events, wakeup_watermark } 1 ------------------------------------------------------------ sys_perf_event_open: pid 1189569 cpu 0 group_fd -1 flags 0x8 sys_perf_event_open failed, error -13 perf_evlist__open: Permission denied ---- end(-2) ---- Leak of file descriptor 6 that opened: 'pipe:[14200347]' ---- unexpected signal (6) ---- iFailed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon #0 0x565358f6666e in child_test_sig_handler builtin-test.c:311 #1 0x7f29ce849df0 in __restore_rt libc_sigaction.c:0 #2 0x7f29ce89e95c in __pthread_kill_implementation pthread_kill.c:44 #3 0x7f29ce849cc2 in raise raise.c:27 #4 0x7f29ce8324ac in abort abort.c:81 #5 0x565358f662d4 in check_leaks builtin-test.c:226 torvalds#6 0x565358f6682e in run_test_child builtin-test.c:344 torvalds#7 0x565358ef7121 in start_command run-command.c:128 torvalds#8 0x565358f67273 in start_test builtin-test.c:545 torvalds#9 0x565358f6771d in __cmd_test builtin-test.c:647 torvalds#10 0x565358f682bd in cmd_test builtin-test.c:849 torvalds#11 0x565358ee5ded in run_builtin perf.c:349 torvalds#12 0x565358ee6085 in handle_internal_command perf.c:401 torvalds#13 0x565358ee61de in run_argv perf.c:448 torvalds#14 0x565358ee6527 in main perf.c:555 torvalds#15 0x7f29ce833ca8 in __libc_start_call_main libc_start_call_main.h:74 torvalds#16 0x7f29ce833d65 in __libc_start_main@@GLIBC_2.34 libc-start.c:128 torvalds#17 0x565358e391c1 in _start perf[851c1] 7: PERF_RECORD_* events & perf_sample fields : FAILED! ``` After: ``` $ perf test 7 7: PERF_RECORD_* events & perf_sample fields : Skip (permissions) ``` Fixes: 16d00fe ("perf tests: Move test__PERF_RECORD into separate object") Signed-off-by: Ian Rogers <irogers@google.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 48918ca ] The test starts a workload and then opens events. If the events fail to open, for example because of perf_event_paranoid, the gopipe of the workload is leaked and the file descriptor leak check fails when the test exits. To avoid this cancel the workload when opening the events fails. Before: ``` $ perf test -vv 7 7: PERF_RECORD_* events & perf_sample fields: --- start --- test child forked, pid 1189568 Using CPUID GenuineIntel-6-B7-1 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0xa00000000 (cpu_atom/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 sys_perf_event_open failed, error -13 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0xa00000000 (cpu_atom/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 exclude_kernel 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 3 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0x400000000 (cpu_core/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 sys_perf_event_open failed, error -13 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0x400000000 (cpu_core/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 exclude_kernel 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 3 Attempt to add: software/cpu-clock/ ..after resolving event: software/config=0/ cpu-clock -> software/cpu-clock/ ------------------------------------------------------------ perf_event_attr: type 1 (PERF_TYPE_SOFTWARE) size 136 config 0x9 (PERF_COUNT_SW_DUMMY) sample_type IP|TID|TIME|CPU read_format ID|LOST disabled 1 inherit 1 mmap 1 comm 1 enable_on_exec 1 task 1 sample_id_all 1 mmap2 1 comm_exec 1 ksymbol 1 bpf_event 1 { wakeup_events, wakeup_watermark } 1 ------------------------------------------------------------ sys_perf_event_open: pid 1189569 cpu 0 group_fd -1 flags 0x8 sys_perf_event_open failed, error -13 perf_evlist__open: Permission denied ---- end(-2) ---- Leak of file descriptor 6 that opened: 'pipe:[14200347]' ---- unexpected signal (6) ---- iFailed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon #0 0x565358f6666e in child_test_sig_handler builtin-test.c:311 #1 0x7f29ce849df0 in __restore_rt libc_sigaction.c:0 #2 0x7f29ce89e95c in __pthread_kill_implementation pthread_kill.c:44 #3 0x7f29ce849cc2 in raise raise.c:27 #4 0x7f29ce8324ac in abort abort.c:81 #5 0x565358f662d4 in check_leaks builtin-test.c:226 torvalds#6 0x565358f6682e in run_test_child builtin-test.c:344 torvalds#7 0x565358ef7121 in start_command run-command.c:128 torvalds#8 0x565358f67273 in start_test builtin-test.c:545 torvalds#9 0x565358f6771d in __cmd_test builtin-test.c:647 torvalds#10 0x565358f682bd in cmd_test builtin-test.c:849 torvalds#11 0x565358ee5ded in run_builtin perf.c:349 torvalds#12 0x565358ee6085 in handle_internal_command perf.c:401 torvalds#13 0x565358ee61de in run_argv perf.c:448 torvalds#14 0x565358ee6527 in main perf.c:555 torvalds#15 0x7f29ce833ca8 in __libc_start_call_main libc_start_call_main.h:74 torvalds#16 0x7f29ce833d65 in __libc_start_main@@GLIBC_2.34 libc-start.c:128 torvalds#17 0x565358e391c1 in _start perf[851c1] 7: PERF_RECORD_* events & perf_sample fields : FAILED! ``` After: ``` $ perf test 7 7: PERF_RECORD_* events & perf_sample fields : Skip (permissions) ``` Fixes: 16d00fe ("perf tests: Move test__PERF_RECORD into separate object") Signed-off-by: Ian Rogers <irogers@google.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
…s' and 'T'
When perf report with annotation for a symbol, press 's' and 'T', then exit
the annotate browser. Once annotate the same symbol, the annotate browser
will crash.
The browser.arch was required to be correctly updated when data type
feature was enabled by 'T'. Usually it was initialized by symbol__annotate2
function. If a symbol has already been correctly annotated at the first
time, it should not call the symbol__annotate2 function again, thus the
browser.arch will not get initialized. Then at the second time to show the
annotate browser, the data type needs to be displayed but the browser.arch
is empty.
Stack trace as below:
Perf: Segmentation fault
-------- backtrace --------
#0 0x55d365 in ui__signal_backtrace setup.c:0
#1 0x7f5ff1a3e930 in __restore_rt libc.so.6[3e930]
#2 0x570f08 in arch__is perf[570f08]
#3 0x562186 in annotate_get_insn_location perf[562186]
#4 0x562626 in __hist_entry__get_data_type annotate.c:0
#5 0x56476d in annotation_line__write perf[56476d]
torvalds#6 0x54e2db in annotate_browser__write annotate.c:0
torvalds#7 0x54d061 in ui_browser__list_head_refresh perf[54d061]
torvalds#8 0x54dc9e in annotate_browser__refresh annotate.c:0
torvalds#9 0x54c03d in __ui_browser__refresh browser.c:0
torvalds#10 0x54ccf8 in ui_browser__run perf[54ccf8]
torvalds#11 0x54eb92 in __hist_entry__tui_annotate perf[54eb92]
torvalds#12 0x552293 in do_annotate hists.c:0
torvalds#13 0x55941c in evsel__hists_browse hists.c:0
torvalds#14 0x55b00f in evlist__tui_browse_hists perf[55b00f]
torvalds#15 0x42ff02 in cmd_report perf[42ff02]
torvalds#16 0x494008 in run_builtin perf.c:0
torvalds#17 0x494305 in handle_internal_command perf.c:0
torvalds#18 0x410547 in main perf[410547]
torvalds#19 0x7f5ff1a295d0 in __libc_start_call_main libc.so.6[295d0]
torvalds#20 0x7f5ff1a29680 in __libc_start_main@@GLIBC_2.34 libc.so.6[29680]
torvalds#21 0x410b75 in _start perf[410b75]
Fixes: 1d4374a ("perf annotate: Add 'T' hot key to toggle data type display")
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Tianyou Li <tianyou.li@intel.com>
…s' and 'T'
When perf report with annotation for a symbol, press 's' and 'T', then exit
the annotate browser. Once annotate the same symbol, the annotate browser
will crash.
The browser.arch was required to be correctly updated when data type
feature was enabled by 'T'. Usually it was initialized by symbol__annotate2
function. If a symbol has already been correctly annotated at the first
time, it should not call the symbol__annotate2 function again, thus the
browser.arch will not get initialized. Then at the second time to show the
annotate browser, the data type needs to be displayed but the browser.arch
is empty.
Stack trace as below:
Perf: Segmentation fault
-------- backtrace --------
#0 0x55d365 in ui__signal_backtrace setup.c:0
#1 0x7f5ff1a3e930 in __restore_rt libc.so.6[3e930]
#2 0x570f08 in arch__is perf[570f08]
#3 0x562186 in annotate_get_insn_location perf[562186]
#4 0x562626 in __hist_entry__get_data_type annotate.c:0
#5 0x56476d in annotation_line__write perf[56476d]
torvalds#6 0x54e2db in annotate_browser__write annotate.c:0
torvalds#7 0x54d061 in ui_browser__list_head_refresh perf[54d061]
torvalds#8 0x54dc9e in annotate_browser__refresh annotate.c:0
torvalds#9 0x54c03d in __ui_browser__refresh browser.c:0
torvalds#10 0x54ccf8 in ui_browser__run perf[54ccf8]
torvalds#11 0x54eb92 in __hist_entry__tui_annotate perf[54eb92]
torvalds#12 0x552293 in do_annotate hists.c:0
torvalds#13 0x55941c in evsel__hists_browse hists.c:0
torvalds#14 0x55b00f in evlist__tui_browse_hists perf[55b00f]
torvalds#15 0x42ff02 in cmd_report perf[42ff02]
torvalds#16 0x494008 in run_builtin perf.c:0
torvalds#17 0x494305 in handle_internal_command perf.c:0
torvalds#18 0x410547 in main perf[410547]
torvalds#19 0x7f5ff1a295d0 in __libc_start_call_main libc.so.6[295d0]
torvalds#20 0x7f5ff1a29680 in __libc_start_main@@GLIBC_2.34 libc.so.6[29680]
torvalds#21 0x410b75 in _start perf[410b75]
Fixes: 1d4374a ("perf annotate: Add 'T' hot key to toggle data type display")
Reviewed-by: James Clark <james.clark@linaro.org>
Tested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tianyou Li <tianyou.li@intel.com>
… 'T'
When perf report with annotation for a symbol, press 's' and 'T', then exit
the annotate browser. Once annotate the same symbol, the annotate browser
will crash.
The browser.arch was required to be correctly updated when data type
feature was enabled by 'T'. Usually it was initialized by symbol__annotate2
function. If a symbol has already been correctly annotated at the first
time, it should not call the symbol__annotate2 function again, thus the
browser.arch will not get initialized. Then at the second time to show the
annotate browser, the data type needs to be displayed but the browser.arch
is empty.
Stack trace as below:
Perf: Segmentation fault
-------- backtrace --------
#0 0x55d365 in ui__signal_backtrace setup.c:0
#1 0x7f5ff1a3e930 in __restore_rt libc.so.6[3e930]
#2 0x570f08 in arch__is perf[570f08]
#3 0x562186 in annotate_get_insn_location perf[562186]
#4 0x562626 in __hist_entry__get_data_type annotate.c:0
#5 0x56476d in annotation_line__write perf[56476d]
torvalds#6 0x54e2db in annotate_browser__write annotate.c:0
torvalds#7 0x54d061 in ui_browser__list_head_refresh perf[54d061]
torvalds#8 0x54dc9e in annotate_browser__refresh annotate.c:0
torvalds#9 0x54c03d in __ui_browser__refresh browser.c:0
torvalds#10 0x54ccf8 in ui_browser__run perf[54ccf8]
torvalds#11 0x54eb92 in __hist_entry__tui_annotate perf[54eb92]
torvalds#12 0x552293 in do_annotate hists.c:0
torvalds#13 0x55941c in evsel__hists_browse hists.c:0
torvalds#14 0x55b00f in evlist__tui_browse_hists perf[55b00f]
torvalds#15 0x42ff02 in cmd_report perf[42ff02]
torvalds#16 0x494008 in run_builtin perf.c:0
torvalds#17 0x494305 in handle_internal_command perf.c:0
torvalds#18 0x410547 in main perf[410547]
torvalds#19 0x7f5ff1a295d0 in __libc_start_call_main libc.so.6[295d0]
torvalds#20 0x7f5ff1a29680 in __libc_start_main@@GLIBC_2.34 libc.so.6[29680]
torvalds#21 0x410b75 in _start perf[410b75]
Fixes: 1d4374a ("perf annotate: Add 'T' hot key to toggle data type display")
Reviewed-by: James Clark <james.clark@linaro.org>
Tested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tianyou Li <tianyou.li@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
The following command will hang consistently when the GPU is being used due to non regular files (e.g. /dev/dri/renderD129, /dev/dri/card2) being opened to read build IDs: $ perf record -asdg -e cpu-clock -- true Change to non blocking reads to avoid the hang here: #0 __libc_pread64 (offset=<optimised out>, count=0, buf=0x7fffffffa4a0, fd=237) at ../sysdeps/unix/sysv/linux/pread64.c:25 #1 __libc_pread64 (fd=237, buf=0x7fffffffa4a0, count=0, offset=0) at ../sysdeps/unix/sysv/linux/pread64.c:23 #2 ?? () from /lib/x86_64-linux-gnu/libelf.so.1 #3 read_build_id (filename=0x5555562df333 "/dev/dri/card2", bid=0x7fffffffb680, block=true) at util/symbol-elf.c:880 #4 filename__read_build_id (filename=0x5555562df333 "/dev/dri/card2", bid=0x7fffffffb680, block=true) at util/symbol-elf.c:924 #5 dsos__read_build_ids_cb (dso=0x5555562df1d0, data=0x7fffffffb750) at util/dsos.c:84 torvalds#6 __dsos__for_each_dso (dsos=0x55555623de68, cb=0x5555557e7030 <dsos__read_build_ids_cb>, data=0x7fffffffb750) at util/dsos.c:59 torvalds#7 dsos__for_each_dso (dsos=0x55555623de68, cb=0x5555557e7030 <dsos__read_build_ids_cb>, data=0x7fffffffb750) at util/dsos.c:503 torvalds#8 dsos__read_build_ids (dsos=0x55555623de68, with_hits=true) at util/dsos.c:107 torvalds#9 machine__read_build_ids (machine=0x55555623da58, with_hits=true) at util/build-id.c:950 torvalds#10 perf_session__read_build_ids (session=0x55555623d840, with_hits=true) at util/build-id.c:956 torvalds#11 write_build_id (ff=0x7fffffffb958, evlist=0x5555562323d0) at util/header.c:327 torvalds#12 do_write_feat (ff=0x7fffffffb958, type=2, p=0x7fffffffb950, evlist=0x5555562323d0, fc=0x0) at util/header.c:3588 torvalds#13 perf_header__adds_write (header=0x55555623d840, evlist=0x5555562323d0, fd=3, fc=0x0) at util/header.c:3632 torvalds#14 perf_session__do_write_header (session=0x55555623d840, evlist=0x5555562323d0, fd=3, at_exit=true, fc=0x0, write_attrs_after_data=false) at util/header.c:3756 torvalds#15 perf_session__write_header (session=0x55555623d840, evlist=0x5555562323d0, fd=3, at_exit=true) at util/header.c:3796 torvalds#16 record__finish_output (rec=0x5555561838d8 <record>) at builtin-record.c:1899 torvalds#17 __cmd_record (rec=0x5555561838d8 <record>, argc=2, argv=0x7fffffffe320) at builtin-record.c:2967 torvalds#18 cmd_record (argc=2, argv=0x7fffffffe320) at builtin-record.c:4453 torvalds#19 run_builtin (p=0x55555618cbb0 <commands+288>, argc=9, argv=0x7fffffffe320) at perf.c:349 torvalds#20 handle_internal_command (argc=9, argv=0x7fffffffe320) at perf.c:401 torvalds#21 run_argv (argcp=0x7fffffffe16c, argv=0x7fffffffe160) at perf.c:445 torvalds#22 main (argc=9, argv=0x7fffffffe320) at perf.c:553 Fixes: 53b00ff ("perf record: Make --buildid-mmap the default") Signed-off-by: James Clark <james.clark@linaro.org>
When using perf record with the `--overwrite` option, a segmentation fault
occurs if an event fails to open. For example:
perf record -e cycles-ct -F 1000 -a --overwrite
Error:
cycles-ct:H: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
perf: Segmentation fault
#0 0x6466b6 in dump_stack debug.c:366
#1 0x646729 in sighandler_dump_stack debug.c:378
#2 0x453fd1 in sigsegv_handler builtin-record.c:722
#3 0x7f8454e65090 in __restore_rt libc-2.32.so[54090]
#4 0x6c5671 in __perf_event__synthesize_id_index synthetic-events.c:1862
#5 0x6c5ac0 in perf_event__synthesize_id_index synthetic-events.c:1943
torvalds#6 0x458090 in record__synthesize builtin-record.c:2075
torvalds#7 0x45a85a in __cmd_record builtin-record.c:2888
torvalds#8 0x45deb6 in cmd_record builtin-record.c:4374
torvalds#9 0x4e5e33 in run_builtin perf.c:349
torvalds#10 0x4e60bf in handle_internal_command perf.c:401
torvalds#11 0x4e6215 in run_argv perf.c:448
torvalds#12 0x4e653a in main perf.c:555
torvalds#13 0x7f8454e4fa72 in __libc_start_main libc-2.32.so[3ea72]
torvalds#14 0x43a3ee in _start ??:0
The --overwrite option implies --tail-synthesize, which collects non-sample
events reflecting the system status when recording finishes. However, when
evsel opening fails (e.g., unsupported event 'cycles-ct'), session->evlist
is not initialized and remains NULL. The code unconditionally calls
record__synthesize() in the error path, which iterates through the NULL
evlist pointer and causes a segfault.
To fix it, move the record__synthesize() call inside the error check block, so
it's only called when there was no error during recording, ensuring that evlist
is properly initialized.
Fixes: 4ea648a ("perf record: Add --tail-synthesize option")
Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
When debugging kernel crashes using GDB, it is helpful to be able to
obtain a backtrace after pgm_check_handler(). Currently this does not
work, because pgm_check_handler() lacks CFI.
Add missing CFI statements.
Old PSW should be obtained from lowcore, which is not addressed
relative to CFA. GNU assembler does not have directives for this, so
synthesize a DW_OP_const8u expression using .cfi_escape.
Make use of uleb128() and data8() directives introduced in binutils
2.45 for this; add a fallback in case they are not available.
Introduce CFI_OFFSET_MULTIPLE() and CFI_RESTORE_MULTIPLE() macros for
describing the effects of STMG and LMG. Unfortunately .cfi_offset and
.cfi_restore do not work with variables like .Lreg, so synthesize the
respective instructions using .cfi_escape.
With this unwinding begins to work. For example, manually corrupting
do_execveat_common()'s filename and setting a breakpoint on
__do_pgm_check() produces the following backtrace:
Thread 8 hit Breakpoint 3, __do_pgm_check (regs=0x37fe0a23b18) at ./arch/s390/include/asm/lowcore.h:224
224 asm_inline(
(gdb) bt
#0 __do_pgm_check (regs=0x37fe0a23b18) at ./arch/s390/include/asm/lowcore.h:224
#1 0x000003ffe0cc08f4 in pgm_check_handler () at arch/s390/kernel/entry.S:339
#2 0x000003ffe04f2510 in __set_nameidata (p=0x37fe0a23c78, dfd=<optimized out>, name=0xfffffff666666667) at fs/namei.c:668
#3 set_nameidata (p=0x37fe0a23c78, dfd=<optimized out>, name=0xfffffff666666667, root=0x0 <fini>) at fs/namei.c:679
#4 do_filp_open (dfd=-100, pathname=0xfffffff666666667, op=0x37fe0a23db0, op@entry=0x3ffe04e5cc2 <do_open_execat+178>) at fs/namei.c:4160
#5 0x000003ffe04e5c72 in do_open_execat (fd=fd@entry=-100, name=name@entry=0xfffffff666666667, flags=flags@entry=0) at fs/exec.c:783
torvalds#6 0x000003ffe04e5dee in alloc_bprm (fd=fd@entry=-100, filename=filename@entry=0xfffffff666666667, flags=0) at fs/exec.c:1410
torvalds#7 0x000003ffe04e6040 in do_execveat_common (fd=fd@entry=-100, filename=0xfffffff666666667, argv=..., envp=..., envp@entry=..., flags=flags@entry=0)
at fs/exec.c:1811
torvalds#8 0x000003ffe04e69c6 in do_execve (filename=<optimized out>, __argv=<optimized out>, __envp=0x2aa21a6bb60) at fs/exec.c:1934
torvalds#9 __do_sys_execve (filename=<optimized out>, argv=<optimized out>, envp=0x2aa21a6bb60) at fs/exec.c:2010
torvalds#10 __se_sys_execve (filename=<optimized out>, argv=<optimized out>, envp=2929732270944) at fs/exec.c:2005
torvalds#11 __s390x_sys_execve (regs=<optimized out>) at fs/exec.c:2005
torvalds#12 0x000003ffe0cb3cb6 in __do_syscall (regs=0x37fe0a23f40, per_trap=<optimized out>) at arch/s390/kernel/syscall.c:125
torvalds#13 0x000003ffe0cc078e in system_call () at arch/s390/kernel/entry.S:261
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Executed command: fsstress -d /mnt -n 600 -p 850 crash> bt PID: 7947 TASK: ffff880160546a70 CPU: 0 COMMAND: "fsstress" #0 [ffff8800dfc07d00] machine_kexec at ffffffff81030db9 #1 [ffff8800dfc07d70] crash_kexec at ffffffff810a7952 #2 [ffff8800dfc07e40] oops_end at ffffffff814aa7c8 #3 [ffff8800dfc07e70] die_nmi at ffffffff814aa969 #4 [ffff8800dfc07ea0] do_nmi_callback at ffffffff8102b07b #5 [ffff8800dfc07f10] do_nmi at ffffffff814aa514 torvalds#6 [ffff8800dfc07f50] nmi at ffffffff814a9d60 [exception RIP: __lookup_tag+100] RIP: ffffffff812274b4 RSP: ffff88016056b998 RFLAGS: 00000287 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000006 RDX: 000000000000001d RSI: ffff88016056bb18 RDI: ffff8800c85366e0 RBP: ffff88016056b9c8 R8: ffff88016056b9e8 R9: 0000000000000000 R10: 000000000000000e R11: ffff8800c8536908 R12: 0000000000000010 R13: 0000000000000040 R14: ffffffffffffffc0 R15: ffff8800c85366e0 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 <NMI exception stack> torvalds#7 [ffff88016056b998] __lookup_tag at ffffffff812274b4 torvalds#8 [ffff88016056b9d0] radix_tree_gang_lookup_tag_slot at ffffffff81227605 torvalds#9 [ffff88016056ba20] find_get_pages_tag at ffffffff810fc110 torvalds#10 [ffff88016056ba80] pagevec_lookup_tag at ffffffff81105e85 torvalds#11 [ffff88016056baa0] write_cache_pages at ffffffff81104c47 torvalds#12 [ffff88016056bbd0] generic_writepages at ffffffff81105014 torvalds#13 [ffff88016056bbe0] do_writepages at ffffffff81105055 torvalds#14 [ffff88016056bbf0] __filemap_fdatawrite_range at ffffffff810fb2cb torvalds#15 [ffff88016056bc40] filemap_write_and_wait_range at ffffffff810fb32a torvalds#16 [ffff88016056bc70] generic_file_direct_write at ffffffff810fb3dc torvalds#17 [ffff88016056bce0] __generic_file_aio_write at ffffffff810fcee5 torvalds#18 [ffff88016056bda0] generic_file_aio_write at ffffffff810fd085 torvalds#19 [ffff88016056bdf0] do_sync_write at ffffffff8114f9ea torvalds#20 [ffff88016056bf00] vfs_write at ffffffff8114fcf8 torvalds#21 [ffff88016056bf30] sys_write at ffffffff81150691 torvalds#22 [ffff88016056bf80] system_call_fastpath at ffffffff8100c0b2 I think this root cause is the following: radix_tree_range_tag_if_tagged() always tags the root tag with settag if the root tag is set with iftag even if there are no iftag tags in the specified range (Of course, there are some iftag tags outside the specified range). =============================================================================== [[[Detailed description]]] (1) Why cannot radix_tree_gang_lookup_tag_slot() return forever? __lookup_tag(): - Return with 0. - Return with the index which is not bigger than the old one as the input parameter. Therefore the following "while" repeats forever because the above conditions cause "ret" not to be updated and the cur_index cannot be changed into the bigger one. (So, radix_tree_gang_lookup_tag_slot() cannot return forever.) radix_tree_gang_lookup_tag_slot(): 1178 while (ret < max_items) { 1179 unsigned int slots_found; 1180 unsigned long next_index; /* Index of next search */ 1181 1182 if (cur_index > max_index) 1183 break; 1184 slots_found = __lookup_tag(node, results + ret, 1185 cur_index, max_items - ret, &next_index, tag); 1186 ret += slots_found; // cannot update ret because slots_found == 0. // so, this while loops forever. 1187 if (next_index == 0) 1188 break; 1189 cur_index = next_index; 1190 } (2) Why does __lookup_tag() return with 0 and doesn't update the index? Assuming the following: - the one of the slot in radix_tree_node is NULL. - the one of the tag which corresponds to the slot sets with PAGECACHE_TAG_TOWRITE or other. - In a certain height(!=0), the corresponding index is 0. a) __lookup_tag() notices that the tag is set. 1005 static unsigned int 1006 __lookup_tag(struct radix_tree_node *slot, void ***results, unsigned long index, 1007 unsigned int max_items, unsigned long *next_index, unsigned int tag) 1008 { 1009 unsigned int nr_found = 0; 1010 unsigned int shift, height; 1011 1012 height = slot->height; 1013 if (height == 0) 1014 goto out; 1015 shift = (height-1) * RADIX_TREE_MAP_SHIFT; 1016 1017 while (height > 0) { 1018 unsigned long i = (index >> shift) & RADIX_TREE_MAP_MASK ; 1019 1020 for (;;) { 1021 if (tag_get(slot, tag, i)) 1022 break; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ * the index is not updated yet. b) __lookup_tag() notices that the slot is NULL. 1023 index &= ~((1UL << shift) - 1); 1024 index += 1UL << shift; 1025 if (index == 0) 1026 goto out; /* 32-bit wraparound */ 1027 i++; 1028 if (i == RADIX_TREE_MAP_SIZE) 1029 goto out; 1030 } 1031 height--; 1032 if (height == 0) { /* Bottom level: grab some items */ ... 1055 } 1056 shift -= RADIX_TREE_MAP_SHIFT; 1057 slot = rcu_dereference_raw(slot->slots[i]); 1058 if (slot == NULL) 1059 break; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ c) __lookup_tag() doesn't update the index and return with 0. 1060 } 1061 out: 1062 *next_index = index; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 1063 return nr_found; 1064 } (3) Why is the slot NULL even if the tag is set? Because radix_tree_range_tag_if_tagged() always sets the root tag with PAGECACHE_TAG_TOWRITE if the root tag is set with PAGECACHE_TAG_DIRTY, even if there is no tag which can be set with PAGECACHE_TAG_TOWRITE in the specified range (from *first_indexp to last_index). Of course, some PAGECACHE_TAG_DIRTY nodes must exist outside the specified range. (radix_tree_range_tag_if_tagged() is called only from tag_pages_for_writeback()) 640 unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root, 641 unsigned long *first_indexp, unsigned long last_index, 642 unsigned long nr_to_tag, 643 unsigned int iftag, unsigned int settag) 644 { 645 unsigned int height = root->height; 646 struct radix_tree_path path[height]; 647 struct radix_tree_path *pathp = path; 648 struct radix_tree_node *slot; 649 unsigned int shift; 650 unsigned long tagged = 0; 651 unsigned long index = *first_indexp; 652 653 last_index = min(last_index, radix_tree_maxindex(height)); 654 if (index > last_index) 655 return 0; 656 if (!nr_to_tag) 657 return 0; 658 if (!root_tag_get(root, iftag)) { 659 *first_indexp = last_index + 1; 660 return 0; 661 } 662 if (height == 0) { 663 *first_indexp = last_index + 1; 664 root_tag_set(root, settag); 665 return 1; 666 } ... 733 root_tag_set(root, settag); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 734 *first_indexp = index; 735 736 return tagged; 737 } As the result, there is no radix_tree_node which is set with PAGECACHE_TAG_TOWRITE but the root tag(radix_tree_root) is set with PAGECACHE_TAG_TOWRITE. [figure: inside radix_tree] (Please see the figure with typewriter font) =========================================== [roottag = DIRTY] | tag=0:NOTHING tag[0 0 0 1] 1:DIRTY [x x x +] 2:WRITEBACK | 3:DIRTY,WRITEBACK p 4:TOWRITE <---> 5:DIRTY,TOWRITE ... specified range (index: 0 to 2) * There is no DIRTY tag within the specified range. (But there is a DIRTY tag outside that range.) | | | | | | | | | after calling tag_pages_for_writeback() | | | | | | | | | v v v v v v v v v [roottag = DIRTY,TOWRITE] | p is "page". tag[0 0 0 1] x is NULL. [x x x +] +- is a pointer to "page". | p * But TOWRITE tag is set on the root tag. ============================================ After that, radix_tree_extend() via radix_tree_insert() is called when the page is added. This function sets the new radix_tree_node with PAGECACHE_TAG_TOWRITE to succeed the status of the root tag. 246 static int radix_tree_extend(struct radix_tree_root *root, unsigned long index) 247 { 248 struct radix_tree_node *node; 249 unsigned int height; 250 int tag; 251 252 /* Figure out what the height should be. */ 253 height = root->height + 1; 254 while (index > radix_tree_maxindex(height)) 255 height++; 256 257 if (root->rnode == NULL) { 258 root->height = height; 259 goto out; 260 } 261 262 do { 263 unsigned int newheight; 264 if (!(node = radix_tree_node_alloc(root))) 265 return -ENOMEM; 266 267 /* Increase the height. */ 268 node->slots[0] = radix_tree_indirect_to_ptr(root->rnode); 269 270 /* Propagate the aggregated tag info into the new root */ 271 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) { 272 if (root_tag_get(root, tag)) 273 tag_set(node, tag, 0); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 274 } =========================================== [roottag = DIRTY,TOWRITE] | : tag[0 0 0 1] [0 0 0 0] [x x x +] [+ x x x] | | p p (new page) | | | | | | | | | after calling radix_tree_insert | | | | | | | | | v v v v v v v v v [roottag = DIRTY,TOWRITE] | tag [5 0 0 0] * DIRTY and TOWRITE tags are [+ + x x] succeeded to the new node. | | tag [0 0 0 1] [0 0 0 0] [x x x +] [+ x x x] | | p p ============================================ After that, the index 3 page is released by remove_from_page_cache(). Then we can make the situation that the tag is set with PAGECACHE_TAG_TOWRITE and that the slot which corresponds to the tag is NULL. =========================================== [roottag = DIRTY,TOWRITE] | tag [5 0 0 0] [+ + x x] | | tag [0 0 0 1] [0 0 0 0] [x x x +] [+ x x x] | | p p (remove) | | | | | | | | | after calling remove_page_cache | | | | | | | | | v v v v v v v v v [roottag = DIRTY,TOWRITE] | tag [4 0 0 0] * Only DIRTY tag is cleared [x + x x] because no TOWRITE tag is existed | in the bottom node. [0 0 0 0] [+ x x x] | p ============================================ To solve this problem Change to that radix_tree_tag_if_tagged() doesn't tag the root tag if it doesn't set any tags within the specified range. Like this. ============================================ 640 unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root, 641 unsigned long *first_indexp, unsigned long last_index, 642 unsigned long nr_to_tag, 643 unsigned int iftag, unsigned int settag) 644 { 650 unsigned long tagged = 0; ... 733 if (tagged) ^^^^^^^^^^^^^^^^^^^^^^^^ 734 root_tag_set(root, settag); 735 *first_indexp = index; 736 737 return tagged; 738 } ============================================ Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Acked-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the pte mapping in generic_perform_write() is unmapped between iov_iter_fault_in_readable() and iov_iter_copy_from_user_atomic(), the "copied" parameter to ->end_write can be zero. ext4 couldn't cope with it with delayed allocations enabled. This skips the i_disksize enlargement logic if copied is zero and no new data was appeneded to the inode. gdb> bt #0 0xffffffff811afe80 in ext4_da_should_update_i_disksize (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x1\ 08000, len=0x1000, copied=0x0, page=0xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2467 #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 #2 0xffffffff810d97f1 in generic_perform_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value o\ ptimized out>, pos=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2440 #3 generic_file_buffered_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value optimized out>, p\ os=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2482 #4 0xffffffff810db5d1 in __generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, ppos=0\ xffff88001e26be40) at mm/filemap.c:2600 #5 0xffffffff810db853 in generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=<value optimi\ zed out>, pos=<value optimized out>) at mm/filemap.c:2632 torvalds#6 0xffffffff811a71aa in ext4_file_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, pos=0x108000) a\ t fs/ext4/file.c:136 torvalds#7 0xffffffff811375aa in do_sync_write (filp=0xffff88003f606a80, buf=<value optimized out>, len=<value optimized out>, \ ppos=0xffff88001e26bf48) at fs/read_write.c:406 torvalds#8 0xffffffff81137e56 in vfs_write (file=0xffff88003f606a80, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x4\ 000, pos=0xffff88001e26bf48) at fs/read_write.c:435 torvalds#9 0xffffffff8113816c in sys_write (fd=<value optimized out>, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x\ 4000) at fs/read_write.c:487 torvalds#10 <signal handler called> torvalds#11 0x00007f120077a390 in __brk_reservation_fn_dmi_alloc__ () torvalds#12 0x0000000000000000 in ?? () gdb> print offset $22 = 0xffffffffffffffff gdb> print idx $23 = 0xffffffff gdb> print inode->i_blkbits $24 = 0xc gdb> up #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 2512 if (ext4_da_should_update_i_disksize(page, end)) { gdb> print start $25 = 0x0 gdb> print end $26 = 0xffffffffffffffff gdb> print pos $27 = 0x108000 gdb> print new_i_size $28 = 0x108000 gdb> print ((struct ext4_inode_info *)((char *)inode-((int)(&((struct ext4_inode_info *)0)->vfs_inode))))->i_disksize $29 = 0xd9000 gdb> down 2467 for (i = 0; i < idx; i++) gdb> print i $30 = 0xd44acbee This is 100% reproducible with some autonuma development code tuned in a very aggressive manner (not normal way even for knumad) which does "exotic" changes to the ptes. It wouldn't normally trigger but I don't see why it can't happen normally if the page is added to swap cache in between the two faults leading to "copied" being zero (which then hangs in ext4). So it should be fixed. Especially possible with lumpy reclaim (albeit disabled if compaction is enabled) as that would ignore the young bits in the ptes. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@kernel.org
…S block during isolation for migration When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 torvalds#6 [d72d3cb4] isolate_migratepages at c030b15a torvalds#7 [d72d3d14] zone_watermark_ok at c02d26cb torvalds#8 [d72d3d2c] compact_zone at c030b8d torvalds#9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Overly indented code should be refactored.
Suggest refactoring excessive indentation of of
if/else/for/do/while/switch statements.
For example:
$ cat t.c
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char **argv)
{
if (1)
if (2)
if (3)
if (4)
if (5)
if (6)
if (7)
if (8)
;
return 0;
}
$ ./scripts/checkpatch.pl -f t.c
WARNING: Too many leading tabs - consider code refactoring
torvalds#12: FILE: t.c:12:
+ if (6)
WARNING: Too many leading tabs - consider code refactoring
torvalds#13: FILE: t.c:13:
+ if (7)
WARNING: Too many leading tabs - consider code refactoring
torvalds#14: FILE: t.c:14:
+ if (8)
total: 0 errors, 3 warnings, 17 lines checked
t.c has style problems, please review.
If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the netdev is already in NETREG_UNREGISTERING/_UNREGISTERED state, do not update the real num tx queues. netdev_queue_update_kobjects() is already called via remove_queue_kobjects() at NETREG_UNREGISTERING time. So, when upper layer driver, e.g., FCoE protocol stack is monitoring the netdev event of NETDEV_UNREGISTER and calls back to LLD ndo_fcoe_disable() to remove extra queues allocated for FCoE, the associated txq sysfs kobjects are already removed, and trying to update the real num queues would cause something like below: ... PID: 25138 TASK: ffff88021e64c440 CPU: 3 COMMAND: "kworker/3:3" #0 [ffff88021f007760] machine_kexec at ffffffff810226d9 #1 [ffff88021f0077d0] crash_kexec at ffffffff81089d2d #2 [ffff88021f0078a0] oops_end at ffffffff813bca78 #3 [ffff88021f0078d0] no_context at ffffffff81029e72 #4 [ffff88021f007920] __bad_area_nosemaphore at ffffffff8102a155 #5 [ffff88021f0079f0] bad_area_nosemaphore at ffffffff8102a23e torvalds#6 [ffff88021f007a00] do_page_fault at ffffffff813bf32e torvalds#7 [ffff88021f007b10] page_fault at ffffffff813bc045 [exception RIP: sysfs_find_dirent+17] RIP: ffffffff81178611 RSP: ffff88021f007bc0 RFLAGS: 00010246 RAX: ffff88021e64c440 RBX: ffffffff8156cc63 RCX: 0000000000000004 RDX: ffffffff8156cc63 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88021f007be0 R8: 0000000000000004 R9: 0000000000000008 R10: ffffffff816fed00 R11: 0000000000000004 R12: 0000000000000000 R13: ffffffff8156cc63 R14: 0000000000000000 R15: ffff8802222a0000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 torvalds#8 [ffff88021f007be8] sysfs_get_dirent at ffffffff81178c07 torvalds#9 [ffff88021f007c18] sysfs_remove_group at ffffffff8117ac27 torvalds#10 [ffff88021f007c48] netdev_queue_update_kobjects at ffffffff813178f9 torvalds#11 [ffff88021f007c88] netif_set_real_num_tx_queues at ffffffff81303e38 torvalds#12 [ffff88021f007cc8] ixgbe_set_num_queues at ffffffffa0249763 [ixgbe] torvalds#13 [ffff88021f007cf8] ixgbe_init_interrupt_scheme at ffffffffa024ea89 [ixgbe] torvalds#14 [ffff88021f007d48] ixgbe_fcoe_disable at ffffffffa0267113 [ixgbe] torvalds#15 [ffff88021f007d68] vlan_dev_fcoe_disable at ffffffffa014fef5 [8021q] torvalds#16 [ffff88021f007d78] fcoe_interface_cleanup at ffffffffa02b7dfd [fcoe] torvalds#17 [ffff88021f007df8] fcoe_destroy_work at ffffffffa02b7f08 [fcoe] torvalds#18 [ffff88021f007e18] process_one_work at ffffffff8105d7ca torvalds#19 [ffff88021f007e68] worker_thread at ffffffff81060513 torvalds#20 [ffff88021f007ee8] kthread at ffffffff810648b6 torvalds#21 [ffff88021f007f48] kernel_thread_helper at ffffffff813c40f4 Signed-off-by: Yi Zou <yi.zou@intel.com> Tested-by: Ross Brattain <ross.b.brattain@intel.com> Tested-by: Stephen Ko <stephen.s.ko@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
…s_replace()
When a chain is updated, a counter can be attached. if so,
the nft_counters_enabled should be increased.
test commands:
%nft add table ip filter
%nft add chain ip filter input { type filter hook input priority 4\; }
%iptables-compat -Z input
%nft delete chain ip filter input
we can see below messages.
[ 286.443720] jump label: negative count!
[ 286.448278] WARNING: CPU: 0 PID: 1459 at kernel/jump_label.c:197 __static_key_slow_dec_cpuslocked+0x6f/0xf0
[ 286.449144] Modules linked in: nf_tables nfnetlink ip_tables x_tables
[ 286.449144] CPU: 0 PID: 1459 Comm: nft Tainted: G W 4.17.0-rc2+ torvalds#12
[ 286.449144] RIP: 0010:__static_key_slow_dec_cpuslocked+0x6f/0xf0
[ 286.449144] RSP: 0018:ffff88010e5176f0 EFLAGS: 00010286
[ 286.449144] RAX: 000000000000001b RBX: ffffffffc0179500 RCX: ffffffffb8a82522
[ 286.449144] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88011b7e5eac
[ 286.449144] RBP: 0000000000000000 R08: ffffed00236fce5c R09: ffffed00236fce5b
[ 286.449144] R10: ffffffffc0179503 R11: ffffed00236fce5c R12: 0000000000000000
[ 286.449144] R13: ffff88011a28e448 R14: ffff88011a28e470 R15: dffffc0000000000
[ 286.449144] FS: 00007f0384328700(0000) GS:ffff88011b600000(0000) knlGS:0000000000000000
[ 286.449144] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 286.449144] CR2: 00007f038394bf10 CR3: 0000000104a86000 CR4: 00000000001006f0
[ 286.449144] Call Trace:
[ 286.449144] static_key_slow_dec+0x6a/0x70
[ 286.449144] nf_tables_chain_destroy+0x19d/0x210 [nf_tables]
[ 286.449144] nf_tables_commit+0x1891/0x1c50 [nf_tables]
[ 286.449144] nfnetlink_rcv+0x1148/0x13d0 [nfnetlink]
[ ... ]
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
lanai_dev_open() can fail. When it fail, lanai->base is unmapped and the pci device is disabled. The caller, lanai_init_one(), then tries to run atm_dev_deregister(). This will subsequently call lanai_dev_close() and use the already released MMIO area. To fix this issue, set the lanai->base to NULL if open fail, and test the flag in lanai_dev_close(). [ 8.324153] lanai: lanai_start() failed, err=19 [ 8.324819] lanai(itf 0): shutting down interface [ 8.325211] BUG: unable to handle page fault for address: ffffc90000180024 [ 8.325781] #PF: supervisor write access in kernel mode [ 8.326215] #PF: error_code(0x0002) - not-present page [ 8.326641] PGD 100000067 P4D 100000067 PUD 100139067 PMD 10013a067 PTE 0 [ 8.327206] Oops: 0002 [#1] SMP KASAN NOPTI [ 8.327557] CPU: 0 PID: 95 Comm: modprobe Not tainted 5.11.0-rc7-00090-gdcc0b49040c7 torvalds#12 [ 8.328229] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-48-gd9c812dda519-4 [ 8.329145] RIP: 0010:lanai_dev_close+0x4f/0xe5 [lanai] [ 8.329587] Code: 00 48 c7 c7 00 d3 01 c0 e8 49 4e 0a c2 48 8d bd 08 02 00 00 e8 6e 52 14 c1 48 80 [ 8.330917] RSP: 0018:ffff8881029ef680 EFLAGS: 00010246 [ 8.331196] RAX: 000000000003fffe RBX: ffff888102fb4800 RCX: ffffffffc001a98a [ 8.331572] RDX: ffffc90000180000 RSI: 0000000000000246 RDI: ffff888102fb4000 [ 8.331948] RBP: ffff888102fb4000 R08: ffffffff8115da8a R09: ffffed102053deaa [ 8.332326] R10: 0000000000000003 R11: ffffed102053dea9 R12: ffff888102fb48a4 [ 8.332701] R13: ffffffffc00123c0 R14: ffff888102fb4b90 R15: ffff888102fb4b88 [ 8.333077] FS: 00007f08eb9056a0(0000) GS:ffff88815b400000(0000) knlGS:0000000000000000 [ 8.333502] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8.333806] CR2: ffffc90000180024 CR3: 0000000102a28000 CR4: 00000000000006f0 [ 8.334182] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 8.334557] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 8.334932] Call Trace: [ 8.335066] atm_dev_deregister+0x161/0x1a0 [atm] [ 8.335324] lanai_init_one.cold+0x20c/0x96d [lanai] [ 8.335594] ? lanai_send+0x2a0/0x2a0 [lanai] [ 8.335831] local_pci_probe+0x6f/0xb0 [ 8.336039] pci_device_probe+0x171/0x240 [ 8.336255] ? pci_device_remove+0xe0/0xe0 [ 8.336475] ? kernfs_create_link+0xb6/0x110 [ 8.336704] ? sysfs_do_create_link_sd.isra.0+0x76/0xe0 [ 8.336983] really_probe+0x161/0x420 [ 8.337181] driver_probe_device+0x6d/0xd0 [ 8.337401] device_driver_attach+0x82/0x90 [ 8.337626] ? device_driver_attach+0x90/0x90 [ 8.337859] __driver_attach+0x60/0x100 [ 8.338065] ? device_driver_attach+0x90/0x90 [ 8.338298] bus_for_each_dev+0xe1/0x140 [ 8.338511] ? subsys_dev_iter_exit+0x10/0x10 [ 8.338745] ? klist_node_init+0x61/0x80 [ 8.338956] bus_add_driver+0x254/0x2a0 [ 8.339164] driver_register+0xd3/0x150 [ 8.339370] ? 0xffffffffc0028000 [ 8.339550] do_one_initcall+0x84/0x250 [ 8.339755] ? trace_event_raw_event_initcall_finish+0x150/0x150 [ 8.340076] ? free_vmap_area_noflush+0x1a5/0x5c0 [ 8.340329] ? unpoison_range+0xf/0x30 [ 8.340532] ? ____kasan_kmalloc.constprop.0+0x84/0xa0 [ 8.340806] ? unpoison_range+0xf/0x30 [ 8.341014] ? unpoison_range+0xf/0x30 [ 8.341217] do_init_module+0xf8/0x350 [ 8.341419] load_module+0x3fe6/0x4340 [ 8.341621] ? vm_unmap_ram+0x1d0/0x1d0 [ 8.341826] ? ____kasan_kmalloc.constprop.0+0x84/0xa0 [ 8.342101] ? module_frob_arch_sections+0x20/0x20 [ 8.342358] ? __do_sys_finit_module+0x108/0x170 [ 8.342604] __do_sys_finit_module+0x108/0x170 [ 8.342841] ? __ia32_sys_init_module+0x40/0x40 [ 8.343083] ? file_open_root+0x200/0x200 [ 8.343298] ? do_sys_open+0x85/0xe0 [ 8.343491] ? filp_open+0x50/0x50 [ 8.343675] ? exit_to_user_mode_prepare+0xfc/0x130 [ 8.343935] do_syscall_64+0x33/0x40 [ 8.344132] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 8.344401] RIP: 0033:0x7f08eb887cf7 [ 8.344594] Code: 48 89 57 30 48 8b 04 24 48 89 47 38 e9 1d a0 02 00 48 89 f8 48 89 f7 48 89 d6 41 [ 8.345565] RSP: 002b:00007ffcd5c98ad8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 8.345962] RAX: ffffffffffffffda RBX: 00000000008fea70 RCX: 00007f08eb887cf7 [ 8.346336] RDX: 0000000000000000 RSI: 00000000008fd9e0 RDI: 0000000000000003 [ 8.346711] RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 [ 8.347085] R10: 00007f08eb8eb300 R11: 0000000000000246 R12: 00000000008fd9e0 [ 8.347460] R13: 0000000000000000 R14: 00000000008fddd0 R15: 0000000000000001 [ 8.347836] Modules linked in: lanai(+) atm [ 8.348065] CR2: ffffc90000180024 [ 8.348244] ---[ end trace 7fdc1c668f2003e5 ]--- [ 8.348490] RIP: 0010:lanai_dev_close+0x4f/0xe5 [lanai] [ 8.348772] Code: 00 48 c7 c7 00 d3 01 c0 e8 49 4e 0a c2 48 8d bd 08 02 00 00 e8 6e 52 14 c1 48 80 [ 8.349745] RSP: 0018:ffff8881029ef680 EFLAGS: 00010246 [ 8.350022] RAX: 000000000003fffe RBX: ffff888102fb4800 RCX: ffffffffc001a98a [ 8.350397] RDX: ffffc90000180000 RSI: 0000000000000246 RDI: ffff888102fb4000 [ 8.350772] RBP: ffff888102fb4000 R08: ffffffff8115da8a R09: ffffed102053deaa [ 8.351151] R10: 0000000000000003 R11: ffffed102053dea9 R12: ffff888102fb48a4 [ 8.351525] R13: ffffffffc00123c0 R14: ffff888102fb4b90 R15: ffff888102fb4b88 [ 8.351918] FS: 00007f08eb9056a0(0000) GS:ffff88815b400000(0000) knlGS:0000000000000000 [ 8.352343] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8.352647] CR2: ffffc90000180024 CR3: 0000000102a28000 CR4: 00000000000006f0 [ 8.353022] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 8.353397] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 8.353958] modprobe (95) used greatest stack depth: 26216 bytes left Signed-off-by: Tong Zhang <ztong0001@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Calling btrfs_qgroup_reserve_meta_prealloc from btrfs_delayed_inode_reserve_metadata can result in flushing delalloc while holding a transaction and delayed node locks. This is deadlock prone. In the past multiple commits: * f2d7f11 ("btrfs: qgroup: don't try to wait flushing if we're already holding a transaction") * 8eee22d ("btrfs: qgroup: don't commit transaction when we already hold the handle") Tried to solve various aspects of this but this was always a whack-a-mole game. Unfortunately those 2 fixes don't solve a deadlock scenario involving btrfs_delayed_node::mutex. Namely, one thread can call btrfs_dirty_inode as a result of reading a file and modifying its atime: PID: 6963 TASK: ffff8c7f3f94c000 CPU: 2 COMMAND: "test" #0 __schedule at ffffffffa529e07d #1 schedule at ffffffffa529e4ff #2 schedule_timeout at ffffffffa52a1bdd #3 wait_for_completion at ffffffffa529eeea <-- sleeps with delayed node mutex held #4 start_delalloc_inodes at ffffffffc0380db5 #5 btrfs_start_delalloc_snapshot at ffffffffc0393836 torvalds#6 try_flush_qgroup at ffffffffc03f04b2 torvalds#7 __btrfs_qgroup_reserve_meta at ffffffffc03f5bb6 <-- tries to reserve space and starts delalloc inodes. torvalds#8 btrfs_delayed_update_inode at ffffffffc03e31aa <-- acquires delayed node mutex torvalds#9 btrfs_update_inode at ffffffffc0385ba8 torvalds#10 btrfs_dirty_inode at ffffffffc038627b <-- TRANSACTIION OPENED torvalds#11 touch_atime at ffffffffa4cf0000 torvalds#12 generic_file_read_iter at ffffffffa4c1f123 torvalds#13 new_sync_read at ffffffffa4ccdc8a torvalds#14 vfs_read at ffffffffa4cd0849 torvalds#15 ksys_read at ffffffffa4cd0bd1 torvalds#16 do_syscall_64 at ffffffffa4a052eb torvalds#17 entry_SYSCALL_64_after_hwframe at ffffffffa540008c This will cause an asynchronous work to flush the delalloc inodes to happen which can try to acquire the same delayed_node mutex: PID: 455 TASK: ffff8c8085fa4000 CPU: 5 COMMAND: "kworker/u16:30" #0 __schedule at ffffffffa529e07d #1 schedule at ffffffffa529e4ff #2 schedule_preempt_disabled at ffffffffa529e80a #3 __mutex_lock at ffffffffa529fdcb <-- goes to sleep, never wakes up. #4 btrfs_delayed_update_inode at ffffffffc03e3143 <-- tries to acquire the mutex #5 btrfs_update_inode at ffffffffc0385ba8 <-- this is the same inode that pid 6963 is holding torvalds#6 cow_file_range_inline.constprop.78 at ffffffffc0386be7 torvalds#7 cow_file_range at ffffffffc03879c1 torvalds#8 btrfs_run_delalloc_range at ffffffffc038894c torvalds#9 writepage_delalloc at ffffffffc03a3c8f torvalds#10 __extent_writepage at ffffffffc03a4c01 torvalds#11 extent_write_cache_pages at ffffffffc03a500b torvalds#12 extent_writepages at ffffffffc03a6de2 torvalds#13 do_writepages at ffffffffa4c277eb torvalds#14 __filemap_fdatawrite_range at ffffffffa4c1e5bb torvalds#15 btrfs_run_delalloc_work at ffffffffc0380987 <-- starts running delayed nodes torvalds#16 normal_work_helper at ffffffffc03b706c torvalds#17 process_one_work at ffffffffa4aba4e4 torvalds#18 worker_thread at ffffffffa4aba6fd torvalds#19 kthread at ffffffffa4ac0a3d torvalds#20 ret_from_fork at ffffffffa54001ff To fully address those cases the complete fix is to never issue any flushing while holding the transaction or the delayed node lock. This patch achieves it by calling qgroup_reserve_meta directly which will either succeed without flushing or will fail and return -EDQUOT. In the latter case that return value is going to be propagated to btrfs_dirty_inode which will fallback to start a new transaction. That's fine as the majority of time we expect the inode will have BTRFS_DELAYED_NODE_INODE_DIRTY flag set which will result in directly copying the in-memory state. Fixes: c69d420 ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT") CC: stable@vger.kernel.org # 5.10+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
The evlist has the maps with its own refcounts so we don't need to set
the pointers to NULL. Otherwise following error was reported by Asan.
# perf test -v 4
4: Read samples using the mmap interface :
--- start ---
test child forked, pid 139782
mmap size 528384B
=================================================================
==139782==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 40 byte(s) in 1 object(s) allocated from:
#0 0x7f1f76daee8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
#1 0x564ba21a0fea in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79
#2 0x564ba21a1a0f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149
#3 0x564ba21a21cf in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166
#4 0x564ba21a21cf in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181
#5 0x564ba1e48298 in test__basic_mmap tests/mmap-basic.c:55
torvalds#6 0x564ba1e278fb in run_test tests/builtin-test.c:428
torvalds#7 0x564ba1e278fb in test_and_print tests/builtin-test.c:458
torvalds#8 0x564ba1e29a53 in __cmd_test tests/builtin-test.c:679
torvalds#9 0x564ba1e29a53 in cmd_test tests/builtin-test.c:825
torvalds#10 0x564ba1e95cb4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
torvalds#11 0x564ba1d1fa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
torvalds#12 0x564ba1d1fa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
torvalds#13 0x564ba1d1fa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
torvalds#14 0x7f1f768e4d09 in __libc_start_main ../csu/libc-start.c:308
...
test child finished with 1
---- end ----
Read samples using the mmap interface: FAILED!
failed to open shell test directory: /home/namhyung/libexec/perf-core/tests/shell
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20210301140409.184570-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The evlist has the maps with its own refcounts so we don't need to set
the pointers to NULL. Otherwise following error was reported by Asan.
Also change the goto label since it doesn't need to have two.
# perf test -v 24
24: Number of exit events of a simple workload :
--- start ---
test child forked, pid 145915
mmap size 528384B
=================================================================
==145915==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 32 byte(s) in 1 object(s) allocated from:
#0 0x7fc44e50d1f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164
#1 0x561cf50f4d2e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23
#2 0x561cf4eeb949 in thread_map__new_by_tid util/thread_map.c:63
#3 0x561cf4db7fd2 in test__task_exit tests/task-exit.c:74
#4 0x561cf4d798fb in run_test tests/builtin-test.c:428
#5 0x561cf4d798fb in test_and_print tests/builtin-test.c:458
torvalds#6 0x561cf4d7ba53 in __cmd_test tests/builtin-test.c:679
torvalds#7 0x561cf4d7ba53 in cmd_test tests/builtin-test.c:825
torvalds#8 0x561cf4de7d04 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
torvalds#9 0x561cf4c71a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
torvalds#10 0x561cf4c71a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
torvalds#11 0x561cf4c71a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
torvalds#12 0x7fc44e042d09 in __libc_start_main ../csu/libc-start.c:308
...
test child finished with 1
---- end ----
Number of exit events of a simple workload: FAILED!
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The evlist has the maps with its own refcounts so we don't need to set
the pointers to NULL. Otherwise following error was reported by Asan.
Also change the goto label since it doesn't need to have two.
# perf test -v 25
25: Software clock events period values :
--- start ---
test child forked, pid 149154
mmap size 528384B
mmap size 528384B
=================================================================
==149154==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 32 byte(s) in 1 object(s) allocated from:
#0 0x7fef5cd071f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164
#1 0x56260d5e8b8e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23
#2 0x56260d3df7a9 in thread_map__new_by_tid util/thread_map.c:63
#3 0x56260d2ac6b2 in __test__sw_clock_freq tests/sw-clock.c:65
#4 0x56260d26d8fb in run_test tests/builtin-test.c:428
#5 0x56260d26d8fb in test_and_print tests/builtin-test.c:458
torvalds#6 0x56260d26fa53 in __cmd_test tests/builtin-test.c:679
torvalds#7 0x56260d26fa53 in cmd_test tests/builtin-test.c:825
torvalds#8 0x56260d2dbb64 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
torvalds#9 0x56260d165a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
torvalds#10 0x56260d165a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
torvalds#11 0x56260d165a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
torvalds#12 0x7fef5c83cd09 in __libc_start_main ../csu/libc-start.c:308
...
test child finished with 1
---- end ----
Software clock events period values : FAILED!
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The evlist and the cpu/thread maps should be released together.
Otherwise following error was reported by Asan.
Note that this test still has memory leaks in DSOs so it still fails
even after this change. I'll take a look at that too.
# perf test -v 26
26: Object code reading :
--- start ---
test child forked, pid 154184
Looking at the vmlinux_path (8 entries long)
symsrc__init: build id mismatch for vmlinux.
symsrc__init: cannot get elf header.
Using /proc/kcore for kernel data
Using /proc/kallsyms for symbols
Parsing event 'cycles'
mmap size 528384B
...
=================================================================
==154184==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 439 byte(s) in 1 object(s) allocated from:
#0 0x7fcb66e77037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154
#1 0x55ad9b7e821e in dso__new_id util/dso.c:1256
#2 0x55ad9b8cfd4a in __machine__addnew_vdso util/vdso.c:132
#3 0x55ad9b8cfd4a in machine__findnew_vdso util/vdso.c:347
#4 0x55ad9b845b7e in map__new util/map.c:176
#5 0x55ad9b8415a2 in machine__process_mmap2_event util/machine.c:1787
torvalds#6 0x55ad9b8fab16 in perf_tool__process_synth_event util/synthetic-events.c:64
torvalds#7 0x55ad9b8fab16 in perf_event__synthesize_mmap_events util/synthetic-events.c:499
torvalds#8 0x55ad9b8fbfdf in __event__synthesize_thread util/synthetic-events.c:741
torvalds#9 0x55ad9b8ff3e3 in perf_event__synthesize_thread_map util/synthetic-events.c:833
torvalds#10 0x55ad9b738585 in do_test_code_reading tests/code-reading.c:608
torvalds#11 0x55ad9b73b25d in test__code_reading tests/code-reading.c:722
torvalds#12 0x55ad9b6f28fb in run_test tests/builtin-test.c:428
torvalds#13 0x55ad9b6f28fb in test_and_print tests/builtin-test.c:458
torvalds#14 0x55ad9b6f4a53 in __cmd_test tests/builtin-test.c:679
torvalds#15 0x55ad9b6f4a53 in cmd_test tests/builtin-test.c:825
torvalds#16 0x55ad9b760cc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
torvalds#17 0x55ad9b5eaa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
torvalds#18 0x55ad9b5eaa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
torvalds#19 0x55ad9b5eaa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
torvalds#20 0x7fcb669acd09 in __libc_start_main ../csu/libc-start.c:308
...
SUMMARY: AddressSanitizer: 471 byte(s) leaked in 2 allocation(s).
test child finished with 1
---- end ----
Object code reading: FAILED!
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The evlist and the cpu/thread maps should be released together.
Otherwise following error was reported by Asan.
$ perf test -v 28
28: Use a dummy software event to keep tracking:
--- start ---
test child forked, pid 156810
mmap size 528384B
=================================================================
==156810==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 40 byte(s) in 1 object(s) allocated from:
#0 0x7f637d2bce8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
#1 0x55cc6295cffa in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79
#2 0x55cc6295da1f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149
#3 0x55cc6295e1df in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166
#4 0x55cc6295e1df in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181
#5 0x55cc626287cf in test__keep_tracking tests/keep-tracking.c:84
torvalds#6 0x55cc625e38fb in run_test tests/builtin-test.c:428
torvalds#7 0x55cc625e38fb in test_and_print tests/builtin-test.c:458
torvalds#8 0x55cc625e5a53 in __cmd_test tests/builtin-test.c:679
torvalds#9 0x55cc625e5a53 in cmd_test tests/builtin-test.c:825
torvalds#10 0x55cc62651cc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
torvalds#11 0x55cc624dba88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
torvalds#12 0x55cc624dba88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
torvalds#13 0x55cc624dba88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
torvalds#14 0x7f637cdf2d09 in __libc_start_main ../csu/libc-start.c:308
SUMMARY: AddressSanitizer: 72 byte(s) leaked in 2 allocation(s).
test child finished with 1
---- end ----
Use a dummy software event to keep tracking: FAILED!
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-7-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The evlist and cpu/thread maps should be released together.
Otherwise the following error was reported by Asan.
$ perf test -v 35
35: Track with sched_switch :
--- start ---
test child forked, pid 159287
Using CPUID GenuineIntel-6-8E-C
mmap size 528384B
1295 events recorded
=================================================================
==159287==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 40 byte(s) in 1 object(s) allocated from:
#0 0x7fa28d9a2e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
#1 0x5652f5a5affa in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79
#2 0x5652f5a5ba1f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149
#3 0x5652f5a5c1df in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166
#4 0x5652f5a5c1df in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181
#5 0x5652f5723bbf in test__switch_tracking tests/switch-tracking.c:350
torvalds#6 0x5652f56e18fb in run_test tests/builtin-test.c:428
torvalds#7 0x5652f56e18fb in test_and_print tests/builtin-test.c:458
torvalds#8 0x5652f56e3a53 in __cmd_test tests/builtin-test.c:679
torvalds#9 0x5652f56e3a53 in cmd_test tests/builtin-test.c:825
torvalds#10 0x5652f574fcc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
torvalds#11 0x5652f55d9a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
torvalds#12 0x5652f55d9a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
torvalds#13 0x5652f55d9a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
torvalds#14 0x7fa28d4d8d09 in __libc_start_main ../csu/libc-start.c:308
SUMMARY: AddressSanitizer: 72 byte(s) leaked in 2 allocation(s).
test child finished with 1
---- end ----
Track with sched_switch: FAILED!
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It missed to call perf_thread_map__put() after using the map.
$ perf test -v 43
43: Synthesize thread map :
--- start ---
test child forked, pid 162640
=================================================================
==162640==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 32 byte(s) in 1 object(s) allocated from:
#0 0x7fd48cdaa1f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164
#1 0x563e6d5f8d0e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23
#2 0x563e6d3ef69a in thread_map__new_by_pid util/thread_map.c:46
#3 0x563e6d2cec90 in test__thread_map_synthesize tests/thread-map.c:97
#4 0x563e6d27d8fb in run_test tests/builtin-test.c:428
#5 0x563e6d27d8fb in test_and_print tests/builtin-test.c:458
torvalds#6 0x563e6d27fa53 in __cmd_test tests/builtin-test.c:679
torvalds#7 0x563e6d27fa53 in cmd_test tests/builtin-test.c:825
torvalds#8 0x563e6d2ebce4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
torvalds#9 0x563e6d175a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
torvalds#10 0x563e6d175a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
torvalds#11 0x563e6d175a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
torvalds#12 0x7fd48c8dfd09 in __libc_start_main ../csu/libc-start.c:308
SUMMARY: AddressSanitizer: 8224 byte(s) leaked in 2 allocation(s).
test child finished with 1
---- end ----
Synthesize thread map: FAILED!
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-9-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It should be released after printing the map.
$ perf test -v 52
52: Print cpu map :
--- start ---
test child forked, pid 172233
=================================================================
==172233==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 156 byte(s) in 1 object(s) allocated from:
#0 0x7fc472518e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
#1 0x55e63b378f7a in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79
#2 0x55e63b37a05c in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:237
#3 0x55e63b056d16 in cpu_map_print tests/cpumap.c:102
#4 0x55e63b056d16 in test__cpu_map_print tests/cpumap.c:120
#5 0x55e63afff8fb in run_test tests/builtin-test.c:428
torvalds#6 0x55e63afff8fb in test_and_print tests/builtin-test.c:458
torvalds#7 0x55e63b001a53 in __cmd_test tests/builtin-test.c:679
torvalds#8 0x55e63b001a53 in cmd_test tests/builtin-test.c:825
torvalds#9 0x55e63b06dc44 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
torvalds#10 0x55e63aef7a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
torvalds#11 0x55e63aef7a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
torvalds#12 0x55e63aef7a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
torvalds#13 0x7fc47204ed09 in __libc_start_main ../csu/libc-start.c:308
...
SUMMARY: AddressSanitizer: 448 byte(s) leaked in 7 allocation(s).
test child finished with 1
---- end ----
Print cpu map: FAILED!
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-11-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It should release the maps at the end.
$ perf test -v 71
71: Convert perf time to TSC :
--- start ---
test child forked, pid 178744
mmap size 528384B
1st event perf time 59207256505278 tsc 13187166645142
rdtsc time 59207256542151 tsc 13187166723020
2nd event perf time 59207256543749 tsc 13187166726393
=================================================================
==178744==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 40 byte(s) in 1 object(s) allocated from:
#0 0x7faf601f9e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
#1 0x55b620cfc00a in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79
#2 0x55b620cfca2f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149
#3 0x55b620cfd1ef in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166
#4 0x55b620cfd1ef in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181
#5 0x55b6209ef1b2 in test__perf_time_to_tsc tests/perf-time-to-tsc.c:73
torvalds#6 0x55b6209828fb in run_test tests/builtin-test.c:428
torvalds#7 0x55b6209828fb in test_and_print tests/builtin-test.c:458
torvalds#8 0x55b620984a53 in __cmd_test tests/builtin-test.c:679
torvalds#9 0x55b620984a53 in cmd_test tests/builtin-test.c:825
torvalds#10 0x55b6209f0cd4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
torvalds#11 0x55b62087aa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
torvalds#12 0x55b62087aa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
torvalds#13 0x55b62087aa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
torvalds#14 0x7faf5fd2fd09 in __libc_start_main ../csu/libc-start.c:308
SUMMARY: AddressSanitizer: 72 byte(s) leaked in 2 allocation(s).
test child finished with 1
---- end ----
Convert perf time to TSC: FAILED!
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-12-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
…date_bw [Why] Below general protection fault observed when WebGL Aquarium is run for longer duration. If drm debug logs are enabled and set to 0x1f then the issue is observed within 10 minutes of run. [ 100.717056] general protection fault, probably for non-canonical address 0x2d33302d32323032: 0000 [#1] PREEMPT SMP NOPTI [ 100.727921] CPU: 3 PID: 1906 Comm: DrmThread Tainted: G W 5.15.30 torvalds#12 d726c6a2d6ebe5cf9223931cbca6892f916fe18b [ 100.754419] RIP: 0010:CalculateSwathWidth+0x1f7/0x44f [ 100.767109] Code: 00 00 00 f2 42 0f 11 04 f0 48 8b 85 88 00 00 00 f2 42 0f 10 04 f0 48 8b 85 98 00 00 00 f2 42 0f 11 04 f0 48 8b 45 10 0f 57 c0 <f3> 42 0f 2a 04 b0 0f 57 c9 f3 43 0f 2a 0c b4 e8 8c e2 f3 ff 48 8b [ 100.781269] RSP: 0018:ffffa9230079eeb0 EFLAGS: 00010246 [ 100.812528] RAX: 2d33302d32323032 RBX: 0000000000000500 RCX: 0000000000000000 [ 100.819656] RDX: 0000000000000001 RSI: ffff99deb712c49c RDI: 0000000000000000 [ 100.826781] RBP: ffffa9230079ef50 R08: ffff99deb712460c R09: ffff99deb712462c [ 100.833907] R10: ffff99deb7124940 R11: ffff99deb7124d70 R12: ffff99deb712ae44 [ 100.841033] R13: 0000000000000001 R14: 0000000000000000 R15: ffffa9230079f0a0 [ 100.848159] FS: 00007af121212640(0000) GS:ffff99deba780000(0000) knlGS:0000000000000000 [ 100.856240] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 100.861980] CR2: 0000209000fe1000 CR3: 000000011b18c000 CR4: 0000000000350ee0 [ 100.869106] Call Trace: [ 100.871555] <TASK> [ 100.873655] ? asm_sysvec_reschedule_ipi+0x12/0x20 [ 100.878449] CalculateSwathAndDETConfiguration+0x1a3/0x6dd [ 100.883937] dml31_ModeSupportAndSystemConfigurationFull+0x2ce4/0x76da [ 100.890467] ? kallsyms_lookup_buildid+0xc8/0x163 [ 100.895173] ? kallsyms_lookup_buildid+0xc8/0x163 [ 100.899874] ? __sprint_symbol+0x80/0x135 [ 100.903883] ? dm_update_plane_state+0x3f9/0x4d2 [ 100.908500] ? symbol_string+0xb7/0xde [ 100.912250] ? number+0x145/0x29b [ 100.915566] ? vsnprintf+0x341/0x5ff [ 100.919141] ? desc_read_finalized_seq+0x39/0x87 [ 100.923755] ? update_load_avg+0x1b9/0x607 [ 100.927849] ? compute_mst_dsc_configs_for_state+0x7d/0xd5b [ 100.933416] ? fetch_pipe_params+0xa4d/0xd0c [ 100.937686] ? dc_fpu_end+0x3d/0xa8 [ 100.941175] dml_get_voltage_level+0x16b/0x180 [ 100.945619] dcn30_internal_validate_bw+0x10e/0x89b [ 100.950495] ? dcn31_validate_bandwidth+0x68/0x1fc [ 100.955285] ? resource_build_scaling_params+0x98b/0xb8c [ 100.960595] ? dcn31_validate_bandwidth+0x68/0x1fc [ 100.965384] dcn31_validate_bandwidth+0x9a/0x1fc [ 100.970001] dc_validate_global_state+0x238/0x295 [ 100.974703] amdgpu_dm_atomic_check+0x9c1/0xbce [ 100.979235] ? _printk+0x59/0x73 [ 100.982467] drm_atomic_check_only+0x403/0x78b [ 100.986912] drm_mode_atomic_ioctl+0x49b/0x546 [ 100.991358] ? drm_ioctl+0x1c1/0x3b3 [ 100.994936] ? drm_atomic_set_property+0x92a/0x92a [ 100.999725] drm_ioctl_kernel+0xdc/0x149 [ 101.003648] drm_ioctl+0x27f/0x3b3 [ 101.007051] ? drm_atomic_set_property+0x92a/0x92a [ 101.011842] amdgpu_drm_ioctl+0x49/0x7d [ 101.015679] __se_sys_ioctl+0x7c/0xb8 [ 101.015685] do_syscall_64+0x5f/0xb8 [ 101.015690] ? __irq_exit_rcu+0x34/0x96 [How] It calles populate_dml_pipes which uses doubles to initialize. Adding FPU protection avoids context switch and probable loss of vba context as there is potential contention while drm debug logs are enabled. Signed-off-by: CHANDAN VURDIGERE NATARAJ <chandan.vurdigerenataraj@amd.com> Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
I got a segfault when using -r option with event groups. The option
makes it run the workload multiple times and it will reuse the evlist
and evsel for each run.
While most of resources are allocated and freed properly, the id hash
in the evlist was not and it resulted in the bug. You can see it with
the address sanitizer like below:
$ perf stat -r 100 -e '{cycles,instructions}' true
=================================================================
==693052==ERROR: AddressSanitizer: heap-use-after-free on
address 0x6080000003d0 at pc 0x558c57732835 bp 0x7fff1526adb0 sp 0x7fff1526ada8
WRITE of size 8 at 0x6080000003d0 thread T0
#0 0x558c57732834 in hlist_add_head /home/namhyung/project/linux/tools/include/linux/list.h:644
#1 0x558c57732834 in perf_evlist__id_hash /home/namhyung/project/linux/tools/lib/perf/evlist.c:237
#2 0x558c57732834 in perf_evlist__id_add /home/namhyung/project/linux/tools/lib/perf/evlist.c:244
#3 0x558c57732834 in perf_evlist__id_add_fd /home/namhyung/project/linux/tools/lib/perf/evlist.c:285
#4 0x558c5747733e in store_evsel_ids util/evsel.c:2765
#5 0x558c5747733e in evsel__store_ids util/evsel.c:2782
torvalds#6 0x558c5730b717 in __run_perf_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:895
torvalds#7 0x558c5730b717 in run_perf_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:1014
torvalds#8 0x558c5730b717 in cmd_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:2446
torvalds#9 0x558c57427c24 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
torvalds#10 0x558c572b1a48 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
torvalds#11 0x558c572b1a48 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
torvalds#12 0x558c572b1a48 in main /home/namhyung/project/linux/tools/perf/perf.c:539
torvalds#13 0x7fcadb9f7d09 in __libc_start_main ../csu/libc-start.c:308
torvalds#14 0x558c572b60f9 in _start (/home/namhyung/project/linux/tools/perf/perf+0x45d0f9)
Actually the nodes in the hash table are struct perf_stream_id and
they were freed in the previous run. Fix it by resetting the hash.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210225035148.778569-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
On systems using the hash MMU, there is a software SLB preload cache that
mirrors the entries loaded into the hardware SLB buffer. This preload
cache is subject to periodic eviction — typically after every 256 context
switches — to remove old entry.
To optimize performance, the kernel skips switch_mmu_context() in
switch_mm_irqs_off() when the prev and next mm_struct are the same.
However, on hash MMU systems, this can lead to inconsistencies between
the hardware SLB and the software preload cache.
If an SLB entry for a process is evicted from the software cache on one
CPU, and the same process later runs on another CPU without executing
switch_mmu_context(), the hardware SLB may retain stale entries. If the
kernel then attempts to reload that entry, it can trigger an SLB
multi-hit error.
The following timeline shows how stale SLB entries are created and can
cause a multi-hit error when a process moves between CPUs without a
MMU context switch.
CPU 0 CPU 1
----- -----
Process P
exec swapper/1
load_elf_binary
begin_new_exc
activate_mm
switch_mm_irqs_off
switch_mmu_context
switch_slb
/*
* This invalidates all
* the entries in the HW
* and setup the new HW
* SLB entries as per the
* preload cache.
*/
context_switch
sched_migrate_task migrates process P to cpu-1
Process swapper/0 context switch (to process P)
(uses mm_struct of Process P) switch_mm_irqs_off()
switch_slb
load_slb++
/*
* load_slb becomes 0 here
* and we evict an entry from
* the preload cache with
* preload_age(). We still
* keep HW SLB and preload
* cache in sync, that is
* because all HW SLB entries
* anyways gets evicted in
* switch_slb during SLBIA.
* We then only add those
* entries back in HW SLB,
* which are currently
* present in preload_cache
* (after eviction).
*/
load_elf_binary continues...
setup_new_exec()
slb_setup_new_exec()
sched_switch event
sched_migrate_task migrates
process P to cpu-0
context_switch from swapper/0 to Process P
switch_mm_irqs_off()
/*
* Since both prev and next mm struct are same we don't call
* switch_mmu_context(). This will cause the HW SLB and SW preload
* cache to go out of sync in preload_new_slb_context. Because there
* was an SLB entry which was evicted from both HW and preload cache
* on cpu-1. Now later in preload_new_slb_context(), when we will try
* to add the same preload entry again, we will add this to the SW
* preload cache and then will add it to the HW SLB. Since on cpu-0
* this entry was never invalidated, hence adding this entry to the HW
* SLB will cause a SLB multi-hit error.
*/
load_elf_binary continues...
START_THREAD
start_thread
preload_new_slb_context
/*
* This tries to add a new EA to preload cache which was earlier
* evicted from both cpu-1 HW SLB and preload cache. This caused the
* HW SLB of cpu-0 to go out of sync with the SW preload cache. The
* reason for this was, that when we context switched back on CPU-0,
* we should have ideally called switch_mmu_context() which will
* bring the HW SLB entries on CPU-0 in sync with SW preload cache
* entries by setting up the mmu context properly. But we didn't do
* that since the prev mm_struct running on cpu-0 was same as the
* next mm_struct (which is true for swapper / kernel threads). So
* now when we try to add this new entry into the HW SLB of cpu-0,
* we hit a SLB multi-hit error.
*/
WARNING: CPU: 0 PID: 1810970 at arch/powerpc/mm/book3s64/slb.c:62
assert_slb_presence+0x2c/0x50(48 results) 02:47:29 [20157/42149]
Modules linked in:
CPU: 0 UID: 0 PID: 1810970 Comm: dd Not tainted 6.16.0-rc3-dirty torvalds#12
VOLUNTARY
Hardware name: IBM pSeries (emulated by qemu) POWER8 (architected)
0x4d0200 0xf000004 of:SLOF,HEAD hv:linux,kvm pSeries
NIP: c00000000015426c LR: c0000000001543b4 CTR: 0000000000000000
REGS: c0000000497c77e0 TRAP: 0700 Not tainted (6.16.0-rc3-dirty)
MSR: 8000000002823033 <SF,VEC,VSX,FP,ME,IR,DR,RI,LE> CR: 28888482 XER: 00000000
CFAR: c0000000001543b0 IRQMASK: 3
<...>
NIP [c00000000015426c] assert_slb_presence+0x2c/0x50
LR [c0000000001543b4] slb_insert_entry+0x124/0x390
Call Trace:
0x7fffceb5ffff (unreliable)
preload_new_slb_context+0x100/0x1a0
start_thread+0x26c/0x420
load_elf_binary+0x1b04/0x1c40
bprm_execve+0x358/0x680
do_execveat_common+0x1f8/0x240
sys_execve+0x58/0x70
system_call_exception+0x114/0x300
system_call_common+0x160/0x2c4
>From the above analysis, during early exec the hardware SLB is cleared,
and entries from the software preload cache are reloaded into hardware
by switch_slb. However, preload_new_slb_context and slb_setup_new_exec
also attempt to load some of the same entries, which can trigger a
multi-hit. In most cases, these additional preloads simply hit existing
entries and add nothing new. Removing these functions avoids redundant
preloads and eliminates the multi-hit issue. This patch removes these
two functions.
We tested process switching performance using the context_switch
benchmark on POWER9/hash, and observed no regression.
Without this patch: 129041 ops/sec
With this patch: 129341 ops/sec
We also measured SLB faults during boot, and the counts are essentially
the same with and without this patch.
SLB faults without this patch: 19727
SLB faults with this patch: 19786
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: <linuxppc-dev@lists.ozlabs.org>
Fixes: 5434ae7 ("powerpc/64s/hash: Add a SLB preload cache")
cc: <stable@vger.kernel.org>
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
When using perf record with the `--overwrite` option, a segmentation fault
occurs if an event fails to open. For example:
perf record -e cycles-ct -F 1000 -a --overwrite
Error:
cycles-ct:H: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
perf: Segmentation fault
#0 0x6466b6 in dump_stack debug.c:366
#1 0x646729 in sighandler_dump_stack debug.c:378
#2 0x453fd1 in sigsegv_handler builtin-record.c:722
#3 0x7f8454e65090 in __restore_rt libc-2.32.so[54090]
#4 0x6c5671 in __perf_event__synthesize_id_index synthetic-events.c:1862
#5 0x6c5ac0 in perf_event__synthesize_id_index synthetic-events.c:1943
torvalds#6 0x458090 in record__synthesize builtin-record.c:2075
torvalds#7 0x45a85a in __cmd_record builtin-record.c:2888
torvalds#8 0x45deb6 in cmd_record builtin-record.c:4374
torvalds#9 0x4e5e33 in run_builtin perf.c:349
torvalds#10 0x4e60bf in handle_internal_command perf.c:401
torvalds#11 0x4e6215 in run_argv perf.c:448
torvalds#12 0x4e653a in main perf.c:555
torvalds#13 0x7f8454e4fa72 in __libc_start_main libc-2.32.so[3ea72]
torvalds#14 0x43a3ee in _start ??:0
The --overwrite option implies --tail-synthesize, which collects non-sample
events reflecting the system status when recording finishes. However, when
evsel opening fails (e.g., unsupported event 'cycles-ct'), session->evlist
is not initialized and remains NULL. The code unconditionally calls
record__synthesize() in the error path, which iterates through the NULL
evlist pointer and causes a segfault.
To fix it, move the record__synthesize() call inside the error check block, so
it's only called when there was no error during recording, ensuring that evlist
is properly initialized.
Fixes: 4ea648a ("perf record: Add --tail-synthesize option")
Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Hi,
Here is what I did to the
CREDITSfile:Sorry for the microscopic commit.
Sincerely,
Jan.