WSL2g doesn't start with Clang Built WSL2 Kernel v60 #19

akuropka · 2021-07-13T14:23:44Z

Microsoft Windows [Version 10.0.22000.65] x64 Enterprise
Ubuntu on Windows Community Preview
upgraded to Ubuntu Impish Indri (development branch) release 21.10
WSL version 2 with g

My Linux doesn't start while using this kernel.
Using standard kernel or self-compiled one based on MS-sources works (5.10.43.3).
WSL shutdown takes long time.

How to trace further?

nathanchance · 2021-07-13T18:28:44Z

This is an Insiders Dev build, correct? I do not usually support the Dev builds because they move so fast. It could be any number of things but it is most likely a configuration change. You might be able to grab /proc/config.gz and upload it for me to take a look at. Otherwise, there is not much that can be done to see why it is not booting as WSL2 is a bit of a black box.

akuropka · 2021-07-13T18:55:01Z

Yeah, it's Dev... 😬
It was more like a question how to trace it down.
Attached the files for reference...
config.diff.txt
config_5.10.txt
config_5.13.txt

We must properly handle an errors when we increase the rlimit counter and the ucounts reference counter. We have to this with RCU protection to prevent possible use-after-free that could occur due to concurrent put_cred_rcu(). The following reproducer triggers the problem: $ cat testcase.sh case "${STEP:-0}" in 0) ulimit -Si 1 ulimit -Hi 1 STEP=1 unshare -rU "$0" killall sleep ;; 1) for i in 1 2 3 4 5; do unshare -rU sleep 5 & done ;; esac with the KASAN report being along the lines of BUG: KASAN: use-after-free in put_ucounts+0x17/0xa0 Write of size 4 at addr ffff8880045f031c by task swapper/2/0 CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.13.0+ #19 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-alt4 04/01/2014 Call Trace: <IRQ> put_ucounts+0x17/0xa0 put_cred_rcu+0xd5/0x190 rcu_core+0x3bf/0xcb0 __do_softirq+0xe3/0x341 irq_exit_rcu+0xbe/0xe0 sysvec_apic_timer_interrupt+0x6a/0x90 </IRQ> asm_sysvec_apic_timer_interrupt+0x12/0x20 default_idle_call+0x53/0x130 do_idle+0x311/0x3c0 cpu_startup_entry+0x14/0x20 secondary_startup_64_no_verify+0xc2/0xcb Allocated by task 127: kasan_save_stack+0x1b/0x40 __kasan_kmalloc+0x7c/0x90 alloc_ucounts+0x169/0x2b0 set_cred_ucounts+0xbb/0x170 ksys_unshare+0x24c/0x4e0 __x64_sys_unshare+0x16/0x20 do_syscall_64+0x37/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 0: kasan_save_stack+0x1b/0x40 kasan_set_track+0x1c/0x30 kasan_set_free_info+0x20/0x30 __kasan_slab_free+0xeb/0x120 kfree+0xaa/0x460 put_cred_rcu+0xd5/0x190 rcu_core+0x3bf/0xcb0 __do_softirq+0xe3/0x341 The buggy address belongs to the object at ffff8880045f0300 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 28 bytes inside of 192-byte region [ffff8880045f0300, ffff8880045f03c0) The buggy address belongs to the page: page:000000008de0a388 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880045f0000 pfn:0x45f0 flags: 0x100000000000200(slab|node=0|zone=1) raw: 0100000000000200 ffffea00000f4640 0000000a0000000a ffff888001042a00 raw: ffff8880045f0000 000000008010000d 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880045f0200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880045f0280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8880045f0300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880045f0380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880045f0400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Disabling lock debugging due to kernel taint Fixes: d646969 ("Reimplement RLIMIT_SIGPENDING on top of ucounts") Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Alexey Gladkov <legion@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Attempting to defragment a Btrfs file containing a transparent huge page immediately deadlocks with the following stack trace: #0 context_switch (kernel/sched/core.c:4940:2) #1 __schedule (kernel/sched/core.c:6287:8) #2 schedule (kernel/sched/core.c:6366:3) #3 io_schedule (kernel/sched/core.c:8389:2) #4 wait_on_page_bit_common (mm/filemap.c:1356:4) #5 __lock_page (mm/filemap.c:1648:2) #6 lock_page (./include/linux/pagemap.h:625:3) #7 pagecache_get_page (mm/filemap.c:1910:4) #8 find_or_create_page (./include/linux/pagemap.h:420:9) #9 defrag_prepare_one_page (fs/btrfs/ioctl.c:1068:9) #10 defrag_one_range (fs/btrfs/ioctl.c:1326:14) #11 defrag_one_cluster (fs/btrfs/ioctl.c:1421:9) #12 btrfs_defrag_file (fs/btrfs/ioctl.c:1523:9) #13 btrfs_ioctl_defrag (fs/btrfs/ioctl.c:3117:9) #14 btrfs_ioctl (fs/btrfs/ioctl.c:4872:10) #15 vfs_ioctl (fs/ioctl.c:51:10) #16 __do_sys_ioctl (fs/ioctl.c:874:11) #17 __se_sys_ioctl (fs/ioctl.c:860:1) #18 __x64_sys_ioctl (fs/ioctl.c:860:1) #19 do_syscall_x64 (arch/x86/entry/common.c:50:14) #20 do_syscall_64 (arch/x86/entry/common.c:80:7) #21 entry_SYSCALL_64+0x7c/0x15b (arch/x86/entry/entry_64.S:113) A huge page is represented by a compound page, which consists of a struct page for each PAGE_SIZE page within the huge page. The first struct page is the "head page", and the remaining are "tail pages". Defragmentation attempts to lock each page in the range. However, lock_page() on a tail page actually locks the corresponding head page. So, if defragmentation tries to lock more than one struct page in a compound page, it tries to lock the same head page twice and deadlocks with itself. Ideally, we should be able to defragment transparent huge pages. However, THP for filesystems is currently read-only, so a lot of code is not ready to use huge pages for I/O. For now, let's just return ETXTBUSY. This can be reproduced with the following on a kernel with CONFIG_READ_ONLY_THP_FOR_FS=y: $ cat create_thp_file.c #include <fcntl.h> #include <stdbool.h> #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <unistd.h> #include <sys/mman.h> static const char zeroes[1024 * 1024]; static const size_t FILE_SIZE = 2 * 1024 * 1024; int main(int argc, char **argv) { if (argc != 2) { fprintf(stderr, "usage: %s PATH\n", argv[0]); return EXIT_FAILURE; } int fd = creat(argv[1], 0777); if (fd == -1) { perror("creat"); return EXIT_FAILURE; } size_t written = 0; while (written < FILE_SIZE) { ssize_t ret = write(fd, zeroes, sizeof(zeroes) < FILE_SIZE - written ? sizeof(zeroes) : FILE_SIZE - written); if (ret < 0) { perror("write"); return EXIT_FAILURE; } written += ret; } close(fd); fd = open(argv[1], O_RDONLY); if (fd == -1) { perror("open"); return EXIT_FAILURE; } /* * Reserve some address space so that we can align the file mapping to * the huge page size. */ void *placeholder_map = mmap(NULL, FILE_SIZE * 2, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (placeholder_map == MAP_FAILED) { perror("mmap (placeholder)"); return EXIT_FAILURE; } void *aligned_address = (void *)(((uintptr_t)placeholder_map + FILE_SIZE - 1) & ~(FILE_SIZE - 1)); void *map = mmap(aligned_address, FILE_SIZE, PROT_READ | PROT_EXEC, MAP_SHARED | MAP_FIXED, fd, 0); if (map == MAP_FAILED) { perror("mmap"); return EXIT_FAILURE; } if (madvise(map, FILE_SIZE, MADV_HUGEPAGE) < 0) { perror("madvise"); return EXIT_FAILURE; } char *line = NULL; size_t line_capacity = 0; FILE *smaps_file = fopen("/proc/self/smaps", "r"); if (!smaps_file) { perror("fopen"); return EXIT_FAILURE; } for (;;) { for (size_t off = 0; off < FILE_SIZE; off += 4096) ((volatile char *)map)[off]; ssize_t ret; bool this_mapping = false; while ((ret = getline(&line, &line_capacity, smaps_file)) > 0) { unsigned long start, end, huge; if (sscanf(line, "%lx-%lx", &start, &end) == 2) { this_mapping = (start <= (uintptr_t)map && (uintptr_t)map < end); } else if (this_mapping && sscanf(line, "FilePmdMapped: %ld", &huge) == 1 && huge > 0) { return EXIT_SUCCESS; } } sleep(6); rewind(smaps_file); fflush(smaps_file); } } $ ./create_thp_file huge $ btrfs fi defrag -czstd ./huge Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>

…emory-allocation-checkpatch-fixes WARNING: Possible unwrapped commit description (prefer a maximum 75 chars per line) #19: [1]: https://lore.kernel.org/lkml/CALvZod4G3SzP3kWxQYn0fj+VgG-G3yWXz=gz17+3N57ru1iajw@mail.gmail.com/t/#m750c8e3231206134293b089feaa090590afa0f60 WARNING: 'cant' may be misspelled - perhaps 'can't'? #158: FILE: mm/vmalloc.c:2858: + /* memory allocation should consider mempolicy, we cant ^^^^ total: 0 errors, 2 warnings, 136 lines checked NOTE: For some of the reported defects, checkpatch may be able to mechanically convert to the typical style using --fix or --fix-inplace. ./patches/mm-vmalloc-introduce-alloc_pages_bulk_array_mempolicy-to-accelerate-memory-allocation.patch has style problems, please review. NOTE: If any of the errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Cc: Chen Wandun <chenwandun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

Trass3r · 2021-12-10T00:51:16Z

Does it result in high CPU usage of the vmmem process?
When I trigger the vGPU support in W10 21H2 via clinfo with this kernel (latest release, self-built tip, clang/gcc built, with/without lto) I get a similar behavior. It works with the default 5.10 kernel.

nathanchance · 2021-12-10T01:42:24Z

It is entirely possible. I do not currently have any interest in debugging this, as I do not use WSLg. I'll take any fixes for this that come my way though.

akuropka · 2022-01-15T19:22:16Z

Update:
I didn't check out this build for some time (I kept using v59), however it behaves with the updated WSL setup the same way as v61 (#21).

When setting bootparams="trace_event=initcall:initcall_start tp_printk=1" in the cmdline, the output_printk() was called, and the spin_lock_irqsave() was called in the atomic and irq disable interrupt context suitation. On the PREEMPT_RT kernel, these locks are replaced with sleepable rt-spinlock, so the stack calltrace will be triggered. Fix it by raw_spin_lock_irqsave when PREEMPT_RT and "trace_event=initcall:initcall_start tp_printk=1" enabled. BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 2, expected: 0 RCU nest depth: 0, expected: 0 Preemption disabled at: [<ffffffff8992303e>] try_to_wake_up+0x7e/0xba0 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.1-rt17+ #19 34c5812404187a875f32bee7977f7367f9679ea7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x60/0x8c dump_stack+0x10/0x12 __might_resched.cold+0x11d/0x155 rt_spin_lock+0x40/0x70 trace_event_buffer_commit+0x2fa/0x4c0 ? map_vsyscall+0x93/0x93 trace_event_raw_event_initcall_start+0xbe/0x110 ? perf_trace_initcall_finish+0x210/0x210 ? probe_sched_wakeup+0x34/0x40 ? ttwu_do_wakeup+0xda/0x310 ? trace_hardirqs_on+0x35/0x170 ? map_vsyscall+0x93/0x93 do_one_initcall+0x217/0x3c0 ? trace_event_raw_event_initcall_level+0x170/0x170 ? push_cpu_stop+0x400/0x400 ? cblist_init_generic+0x241/0x290 kernel_init_freeable+0x1ac/0x347 ? _raw_spin_unlock_irq+0x65/0x80 ? rest_init+0xf0/0xf0 kernel_init+0x1e/0x150 ret_from_fork+0x22/0x30 </TASK> Link: https://lkml.kernel.org/r/20220419013910.894370-1-jun.miao@intel.com Signed-off-by: Jun Miao <jun.miao@intel.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

When we run out of module space address with ko insertion, and with MODULE_PLTS, module would turn to try to find memory from VMALLOC address space. Unfortunately, with KASAN enabled, VMALLOC doesn't work without KASAN_VMALLOC, thus select KASAN_VMALLOC by default. 8<--- cut here --- Unable to handle kernel paging request at virtual address bd300860 [bd300860] *pgd=41cf1811, *pte=41cf26df, *ppte=41cf265f Internal error: Oops: 80f [#1] PREEMPT SMP ARM Modules linked in: hello(O+) CPU: 0 PID: 89 Comm: insmod Tainted: G O 5.16.0-rc6+ #19 Hardware name: Generic DT based system PC is at mmioset+0x30/0xa8 LR is at 0x0 pc : [<c077ed30>] lr : [<00000000>] psr: 20000013 sp : c451fc18 ip : bd300860 fp : c451fc2c r10: f18042cc r9 : f18042d0 r8 : 00000000 r7 : 00000001 r6 : 00000003 r5 : 01312d00 r4 : f1804300 r3 : 00000000 r2 : 00262560 r1 : 00000000 r0 : bd300860 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 43e9406a DAC: 00000051 Register r0 information: non-paged memory Register r1 information: NULL pointer Register r2 information: non-paged memory Register r3 information: NULL pointer Register r4 information: 4887-page vmalloc region starting at 0xf1802000 allocated at load_module+0x14f4/0x32a8 Register r5 information: non-paged memory Register r6 information: non-paged memory Register r7 information: non-paged memory Register r8 information: NULL pointer Register r9 information: 4887-page vmalloc region starting at 0xf1802000 allocated at load_module+0x14f4/0x32a8 Register r10 information: 4887-page vmalloc region starting at 0xf1802000 allocated at load_module+0x14f4/0x32a8 Register r11 information: non-slab/vmalloc memory Register r12 information: non-paged memory Process insmod (pid: 89, stack limit = 0xc451c000) Stack: (0xc451fc18 to 0xc4520000) fc00: f18041f0 c04803a4 fc20: c451fc44 c451fc30 c048053c c0480358 f1804030 01312cff c451fc64 c451fc48 fc40: c047f330 c0480500 f18040c0 c1b52ccc 00000001 c5be7700 c451fc74 c451fc68 fc60: f1802098 c047f300 c451fcb4 c451fc78 c026106c f180208c c4880004 00000000 fc80: c451fcb4 bf001000 c044ff48 c451fec0 f18040c0 00000000 c1b54cc4 00000000 fca0: c451fdf0 f1804268 c451fe64 c451fcb8 c0264e88 c0260d48 ffff8000 00007fff fcc0: f18040c0 c025cd00 c451fd14 00000003 0157f008 f1804258 f180425c f1804174 fce0: f1804154 f180424c f18041f0 f180414c f1804178 f18041c0 bf0025d4 188a3fa8 fd00: 0000009e f1804170 f2b18000 c451ff10 c0d92e40 f180416c c451feec 00000001 fd20: 00000000 c451fec8 c451fe20 c451fed0 f18040cc 00000000 f17ea000 c451fdc0 fd40: 41b58ab3 c1387729 c0261c28 c047fb5c c451fe2c c451fd60 c0525308 c048033c fd60: 188a3fb4 c3ccb090 c451fe00 c3ccb080 00000000 00000000 00016920 00000000 fd80: c02d0388 c047f55c c02d0388 00000000 c451fddc c451fda0 c02d0388 00000000 fda0: 41b58ab3 c13a72d0 c0524ff0 c1705f48 c451fdfc c451fdc0 c02d0388 c047f55c fdc0: 00016920 00000000 00000003 c1bb2384 c451fdfc c3ccb080 c1bb2384 00000000 fde0: 00000000 00000000 00000000 00000000 c451fe1c c451fe00 c04e9d70 c1705f48 fe00: c1b54cc4 c1bbc71c c3ccb080 00000000 c3ccb080 00000000 00000003 c451fec0 fe20: c451fe64 c451fe30 c0525918 c0524ffc c451feb0 c1705f48 00000000 c1b54cc4 fe40: b78a3fd0 c451ff60 00000000 0157f008 00000003 c451fec0 c451ffa4 c451fe68 fe60: c0265480 c0261c34 c451feb0 7fffffff 00000000 00000002 00000000 c4880000 fe80: 41b58ab3 c138777b c02652cc c04803ec 000a0000 c451ff00 ffffff9c b6ac9f60 fea0: c451fed4 c1705f48 c04a4a90 b78a3fdc f17ea000 ffffff9c b6ac9f60 c0100244 fec0: f17ea21a f17ea300 f17ea000 00016920 f1800240 f18000ac f17fb7dc 01316000 fee0: 013161b0 00002590 01316250 00000000 00000000 00000000 00002580 00000029 ff00: 0000002a 00000013 00000000 0000000c 00000000 00000000 0157f004 c451ffb0 ff20: c1719be0 aed6f410 c451ff74 c451ff38 c0c4103c c0c407d0 c451ff84 c451ff48 ff40: 00000805 c02c8658 c1604230 c1719c30 00000805 0157f004 00000005 c451ffb0 ff60: c1719be0 aed6f410 c451ffac c451ff78 c0122130 c1705f48 c451ffac 0157f008 ff80: 00000006 0000005f 0000017b c0100244 c4880000 0000017b 00000000 c451ffa8 ffa0: c0100060 c02652d8 0157f008 00000006 00000003 0157f008 00000000 b6ac9f60 ffc0: 0157f008 00000006 0000005f 0000017b 00000000 00000000 aed85f74 00000000 ffe0: b6ac9cd8 b6ac9cc8 00030200 aecf2d60 a0000010 00000003 00000000 00000000 Backtrace: [<c048034c>] (kasan_poison) from [<c048053c>] (kasan_unpoison+0x48/0x5c) [<c04804f4>] (kasan_unpoison) from [<c047f330>] (__asan_register_globals+0x3c/0x64) r5:01312cff r4:f1804030 [<c047f2f4>] (__asan_register_globals) from [<f1802098>] (_sub_I_65535_1+0x18/0xf80 [hello]) r7:c5be7700 r6:00000001 r5:c1b52ccc r4:f18040c0 [<f1802080>] (_sub_I_65535_1 [hello]) from [<c026106c>] (do_init_module+0x330/0x72c) [<c0260d3c>] (do_init_module) from [<c0264e88>] (load_module+0x3260/0x32a8) r10:f1804268 r9:c451fdf0 r8:00000000 r7:c1b54cc4 r6:00000000 r5:f18040c0 r4:c451fec0 [<c0261c28>] (load_module) from [<c0265480>] (sys_finit_module+0x1b4/0x1e8) r10:c451fec0 r9:00000003 r8:0157f008 r7:00000000 r6:c451ff60 r5:b78a3fd0 r4:c1b54cc4 [<c02652cc>] (sys_finit_module) from [<c0100060>] (ret_fast_syscall+0x0/0x1c) Exception stack(0xc451ffa8 to 0xc451fff0) ffa0: 0157f008 00000006 00000003 0157f008 00000000 b6ac9f60 ffc0: 0157f008 00000006 0000005f 0000017b 00000000 00000000 aed85f74 00000000 ffe0: b6ac9cd8 b6ac9cc8 00030200 aecf2d60 r10:0000017b r9:c4880000 r8:c0100244 r7:0000017b r6:0000005f r5:00000006 r4:0157f008 Code: e92d4100 e1a08001 e1a0e003 e2522040 (a8ac410a) ---[ end trace df6e12843197b6f5 ]--- Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com> Tested-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

After commit f2d3b9a ("ARM: 9220/1: amba: Remove deferred device addition"), it became possible for amba_read_periphid() to be invoked concurrently from two threads for a particular AMBA device. Consider the case where a thread (T0) is registering an AMBA driver, and searching for all of the devices it can match with on the AMBA bus. Suppose that another thread (T1) is executing the deferred probe work, and is searching through all of the AMBA drivers on the bus for a driver that matches a particular AMBA device. Assume that both threads begin operating on the same AMBA device and the device's peripheral ID is still unknown. In this scenario, the amba_match() function will be invoked for the same AMBA device by both threads, which means amba_read_periphid() can also be invoked by both threads, and both threads will be able to manipulate the AMBA device's pclk pointer without any synchronization. It's possible that one thread will initialize the pclk pointer, then the other thread will re-initialize it, overwriting the previous value, and both will race to free the same pclk, resulting in a use-after-free for whichever thread frees the pclk last. Add a lock per AMBA device to synchronize the handling with detecting the peripheral ID to avoid the use-after-free scenario. The following KFENCE bug report helped detect this problem: ================================================================== BUG: KFENCE: use-after-free read in clk_disable+0x14/0x34 Use-after-free read at 0x(ptrval) (in kfence-#19): clk_disable+0x14/0x34 amba_read_periphid+0xdc/0x134 amba_match+0x3c/0x84 __driver_attach+0x20/0x158 bus_for_each_dev+0x74/0xc0 bus_add_driver+0x154/0x1e8 driver_register+0x88/0x11c do_one_initcall+0x8c/0x2fc kernel_init_freeable+0x190/0x220 kernel_init+0x10/0x108 ret_from_fork+0x14/0x3c 0x0 kfence-#19: 0x(ptrval)-0x(ptrval), size=36, cache=kmalloc-64 allocated by task 8 on cpu 0 at 11.629931s: clk_hw_create_clk+0x38/0x134 amba_get_enable_pclk+0x10/0x68 amba_read_periphid+0x28/0x134 amba_match+0x3c/0x84 __device_attach_driver+0x2c/0xc4 bus_for_each_drv+0x80/0xd0 __device_attach+0xb0/0x1f0 bus_probe_device+0x88/0x90 deferred_probe_work_func+0x8c/0xc0 process_one_work+0x23c/0x690 worker_thread+0x34/0x488 kthread+0xd4/0xfc ret_from_fork+0x14/0x3c 0x0 freed by task 8 on cpu 0 at 11.630095s: amba_read_periphid+0xec/0x134 amba_match+0x3c/0x84 __device_attach_driver+0x2c/0xc4 bus_for_each_drv+0x80/0xd0 __device_attach+0xb0/0x1f0 bus_probe_device+0x88/0x90 deferred_probe_work_func+0x8c/0xc0 process_one_work+0x23c/0x690 worker_thread+0x34/0x488 kthread+0xd4/0xfc ret_from_fork+0x14/0x3c 0x0 Cc: Saravana Kannan <saravanak@google.com> Cc: patches@armlinux.org.uk Fixes: f2d3b9a ("ARM: 9220/1: amba: Remove deferred device addition") Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

DRM commit_tails() will disable downstream crtc/encoder/bridge if both disable crtc is required and crtc->active is set before pushing a new frame downstream. There is a rare case that user space display manager issue an extra screen update immediately followed by close DRM device while down stream display interface is disabled. This extra screen update will timeout due to the downstream interface is disabled but will cause crtc->active be set. Hence the followed commit_tails() called by drm_release() will pass the disable downstream crtc/encoder/bridge conditions checking even downstream interface is disabled. This cause the crash to happen at dp_bridge_disable() due to it trying to access the main link register to push the idle pattern out while main link clocks is disabled. This patch adds atomic_check to prevent the extra frame will not be pushed down if display interface is down so that crtc->active will not be set neither. This will fail the conditions checking of disabling down stream crtc/encoder/bridge which prevent drm_release() from calling dp_bridge_disable() so that crash at dp_bridge_disable() prevented. There is no protection in the DRM framework to check if the display pipeline has been already disabled before trying again. The only check is the crtc_state->active but this is controlled by usermode using UAPI. Hence if the usermode sets this and then crashes, the driver needs to protect against double disable. SError Interrupt on CPU7, code 0x00000000be000411 -- SError CPU: 7 PID: 3878 Comm: Xorg Not tainted 5.19.0-stb-cbq #19 Hardware name: Google Lazor (rev3 - 8) (DT) pstate: a04000c9 (NzCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __cmpxchg_case_acq_32+0x14/0x2c lr : do_raw_spin_lock+0xa4/0xdc sp : ffffffc01092b6a0 x29: ffffffc01092b6a0 x28: 0000000000000028 x27: 0000000000000038 x26: 0000000000000004 x25: ffffffd2973dce48 x24: 0000000000000000 x23: 00000000ffffffff x22: 00000000ffffffff x21: ffffffd2978d0008 x20: ffffffd2978d0008 x19: ffffff80ff759fc0 x18: 0000000000000000 x17: 004800a501260460 x16: 0441043b04600438 x15: 04380000089807d0 x14: 07b0089807800780 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000438 x10: 00000000000007d0 x9 : ffffffd2973e09e4 x8 : ffffff8092d53300 x7 : ffffff808902e8b8 x6 : 0000000000000001 x5 : ffffff808902e880 x4 : 0000000000000000 x3 : ffffff80ff759fc0 x2 : 0000000000000001 x1 : 0000000000000000 x0 : ffffff80ff759fc0 Kernel panic - not syncing: Asynchronous SError Interrupt CPU: 7 PID: 3878 Comm: Xorg Not tainted 5.19.0-stb-cbq #19 Hardware name: Google Lazor (rev3 - 8) (DT) Call trace: dump_backtrace.part.0+0xbc/0xe4 show_stack+0x24/0x70 dump_stack_lvl+0x68/0x84 dump_stack+0x18/0x34 panic+0x14c/0x32c nmi_panic+0x58/0x7c arm64_serror_panic+0x78/0x84 do_serror+0x40/0x64 el1h_64_error_handler+0x30/0x48 el1h_64_error+0x68/0x6c __cmpxchg_case_acq_32+0x14/0x2c _raw_spin_lock_irqsave+0x38/0x4c lock_timer_base+0x40/0x78 __mod_timer+0xf4/0x25c schedule_timeout+0xd4/0xfc __wait_for_common+0xac/0x140 wait_for_completion_timeout+0x2c/0x54 dp_ctrl_push_idle+0x40/0x88 dp_bridge_disable+0x24/0x30 drm_atomic_bridge_chain_disable+0x90/0xbc drm_atomic_helper_commit_modeset_disables+0x198/0x444 msm_atomic_commit_tail+0x1d0/0x374 commit_tail+0x80/0x108 drm_atomic_helper_commit+0x118/0x11c drm_atomic_commit+0xb4/0xe0 drm_client_modeset_commit_atomic+0x184/0x224 drm_client_modeset_commit_locked+0x58/0x160 drm_client_modeset_commit+0x3c/0x64 __drm_fb_helper_restore_fbdev_mode_unlocked+0x98/0xac drm_fb_helper_set_par+0x74/0x80 drm_fb_helper_hotplug_event+0xdc/0xe0 __drm_fb_helper_restore_fbdev_mode_unlocked+0x7c/0xac drm_fb_helper_restore_fbdev_mode_unlocked+0x20/0x2c drm_fb_helper_lastclose+0x20/0x2c drm_lastclose+0x44/0x6c drm_release+0x88/0xd4 __fput+0x104/0x220 ____fput+0x1c/0x28 task_work_run+0x8c/0x100 do_exit+0x450/0x8d0 do_group_exit+0x40/0xac __wake_up_parent+0x0/0x38 invoke_syscall+0x84/0x11c el0_svc_common.constprop.0+0xb8/0xe4 do_el0_svc+0x8c/0xb8 el0_svc+0x2c/0x54 el0t_64_sync_handler+0x120/0x1c0 el0t_64_sync+0x190/0x194 SMP: stopping secondary CPUs Kernel Offset: 0x128e800000 from 0xffffffc008000000 PHYS_OFFSET: 0x80000000 CPU features: 0x800,00c2a015,19801c82 Memory Limit: none Changes in v2: -- add more commit text Changes in v3: -- add comments into dp_bridge_atomic_check() Changes in v4: -- rewording the comment into dp_bridge_atomic_check() Changes in v5: -- removed quote x at end of commit text Changes in v6: -- removed quote x at end of comment in dp_bridge_atomic_check() Fixes: 8a3b4c1 ("drm/msm/dp: employ bridge mechanism for display enable and disable") Reported-by: Leonard Lausen <leonard@lausen.nl> Suggested-by: Rob Clark <robdclark@gmail.com> Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/17 Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com> Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com> Patchwork: https://patchwork.freedesktop.org/patch/505331/ Link: https://lore.kernel.org/r/1664408211-25314-1-git-send-email-quic_khsieh@quicinc.com Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>

nathanchance added bug Something isn't working help wanted Extra attention is needed wontfix This will not be worked on labels Dec 10, 2021

nathanchance mentioned this issue Jan 15, 2022

[Clang Built WSL2 Kernel v61] dxgk:err: invalid event pointer / unexpected packet type #21

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akuropka closed this as completed Jan 15, 2022

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WSL2g doesn't start with Clang Built WSL2 Kernel v60 #19

WSL2g doesn't start with Clang Built WSL2 Kernel v60 #19

akuropka commented Jul 13, 2021

nathanchance commented Jul 13, 2021

akuropka commented Jul 13, 2021

Trass3r commented Dec 10, 2021

nathanchance commented Dec 10, 2021

akuropka commented Jan 15, 2022

WSL2g doesn't start with Clang Built WSL2 Kernel v60 #19

WSL2g doesn't start with Clang Built WSL2 Kernel v60 #19

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akuropka commented Jul 13, 2021

nathanchance commented Jul 13, 2021

akuropka commented Jul 13, 2021

Trass3r commented Dec 10, 2021

nathanchance commented Dec 10, 2021

akuropka commented Jan 15, 2022