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Pull request for series with
subject: bpftool: fix build failure
version: 3
url: https://patchwork.ozlabs.org/project/netdev/list/?series=201644

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kernel-patches-bot and others added 2 commits September 14, 2020 18:49
  make -C tools/testing/selftests/bpf -j20
I hit the following errors:
  ...
  GEN      /net-next/tools/testing/selftests/bpf/tools/build/bpftool/Documentation/bpftool-gen.8
  <stdin>:75: (WARNING/2) Block quote ends without a blank line; unexpected unindent.
  <stdin>:71: (WARNING/2) Literal block ends without a blank line; unexpected unindent.
  <stdin>:85: (WARNING/2) Literal block ends without a blank line; unexpected unindent.
  <stdin>:57: (WARNING/2) Block quote ends without a blank line; unexpected unindent.
  <stdin>:66: (WARNING/2) Literal block ends without a blank line; unexpected unindent.
  <stdin>:109: (WARNING/2) Literal block ends without a blank line; unexpected unindent.
  <stdin>:175: (WARNING/2) Literal block ends without a blank line; unexpected unindent.
  <stdin>:273: (WARNING/2) Literal block ends without a blank line; unexpected unindent.
  make[1]: *** [/net-next/tools/testing/selftests/bpf/tools/build/bpftool/Documentation/bpftool-perf.8] Error 12
  make[1]: *** Waiting for unfinished jobs....
  make[1]: *** [/net-next/tools/testing/selftests/bpf/tools/build/bpftool/Documentation/bpftool-iter.8] Error 12
  make[1]: *** [/net-next/tools/testing/selftests/bpf/tools/build/bpftool/Documentation/bpftool-struct_ops.8] Error 12
  ...

I am using:
  -bash-4.4$ rst2man --version
  rst2man (Docutils 0.11 [repository], Python 2.7.5, on linux2)
  -bash-4.4$

The Makefile generated final .rst file (e.g., bpftool-cgroup.rst) looks like
  ...
      ID       AttachType      AttachFlags     Name
  \n SEE ALSO\n========\n\t**bpf**\ (2),\n\t**bpf-helpers**\
  (7),\n\t**bpftool**\ (8),\n\t**bpftool-btf**\
  (8),\n\t**bpftool-feature**\ (8),\n\t**bpftool-gen**\
  (8),\n\t**bpftool-iter**\ (8),\n\t**bpftool-link**\
  (8),\n\t**bpftool-map**\ (8),\n\t**bpftool-net**\
  (8),\n\t**bpftool-perf**\ (8),\n\t**bpftool-prog**\
  (8),\n\t**bpftool-struct_ops**\ (8)\n

The rst2man generated .8 file looks like
Literal block ends without a blank line; unexpected unindent.
 .sp
 n SEEALSOn========nt**bpf**(2),nt**bpf\-helpers**(7),nt**bpftool**(8),nt**bpftool\-btf**(8),nt**
 bpftool\-feature**(8),nt**bpftool\-gen**(8),nt**bpftool\-iter**(8),nt**bpftool\-link**(8),nt**
 bpftool\-map**(8),nt**bpftool\-net**(8),nt**bpftool\-perf**(8),nt**bpftool\-prog**(8),nt**
 bpftool\-struct_ops**(8)n

Looks like that particular version of rst2man prefers to have actual new line
instead of \n.

Since `echo -e` may not be available in some environment, let us use `printf`.
Format string "%b" is used for `printf` to ensure all escape characters are
interpretted properly.

Cc: Quentin Monnet <quentin@isovalent.com>
Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Fixes: 18841da ("tools: bpftool: Automate generation for "SEE ALSO" sections in man pages")
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/bpf/bpftool/Documentation/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
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At least one diff in series https://patchwork.ozlabs.org/project/netdev/list/?series=201644 irrelevant now. Closing PR.

@kernel-patches-bot kernel-patches-bot deleted the series/201460 branch September 15, 2020 17:50
kernel-patches-bot pushed a commit that referenced this pull request Feb 13, 2021
Syzkaller was able to trigger the following splat again:

WARNING: CPU: 1 PID: 12512 at net/mptcp/protocol.c:761 mptcp_reset_timer+0x12a/0x160 net/mptcp/protocol.c:761
Modules linked in:
CPU: 1 PID: 12512 Comm: kworker/1:6 Not tainted 5.10.0-rc6 #52
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:mptcp_reset_timer+0x12a/0x160 net/mptcp/protocol.c:761
Code: e8 4b 0c ad ff e8 56 21 88 fe 48 b8 00 00 00 00 00 fc ff df 48 c7 04 03 00 00 00 00 48 83 c4 40 5b 5d 41 5c c3 e8 36 21 88 fe <0f> 0b 41 bc c8 00 00 00 eb 98 e8 e7 b1 af fe e9 30 ff ff ff 48 c7
RSP: 0018:ffffc900018c7c68 EFLAGS: 00010293
RAX: ffff888108cb1c80 RBX: 1ffff92000318f8d RCX: ffffffff82ad0307
RDX: 0000000000000000 RSI: ffffffff82ad036a RDI: 0000000000000007
RBP: ffff888113e2d000 R08: ffff888108cb1c80 R09: ffffed10227c5ab7
R10: ffff888113e2d5b7 R11: ffffed10227c5ab6 R12: 0000000000000000
R13: ffff88801f100000 R14: ffff888113e2d5b0 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88811b500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd76a874ef8 CR3: 000000001689c005 CR4: 0000000000170ee0
Call Trace:
 mptcp_worker+0xaa4/0x1560 net/mptcp/protocol.c:2334
 process_one_work+0x8d3/0x1200 kernel/workqueue.c:2272
 worker_thread+0x9c/0x1090 kernel/workqueue.c:2418
 kthread+0x303/0x410 kernel/kthread.c:292
 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:296

The mptcp_worker tries to update the MPTCP retransmission timer
even if such timer is not currently scheduled.

The mptcp_rtx_head() return value is bogus: we can have enqueued
data not yet transmitted. The above may additionally cause spurious,
unneeded MPTCP-level retransmissions.

Fix the issue adding an explicit clearing of the rtx queue before
trying to retransmit and checking for unacked data.
Additionally drop an unneeded timer stop call and the unused
mptcp_rtx_tail() helper.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Fixes: 6e628cd ("mptcp: use mptcp release_cb for delayed tasks")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
kernel-patches-bot pushed a commit that referenced this pull request Jan 28, 2023
The inline assembly for arm64's cmpxchg_double*() implementations use a
+Q constraint to hazard against other accesses to the memory location
being exchanged. However, the pointer passed to the constraint is a
pointer to unsigned long, and thus the hazard only applies to the first
8 bytes of the location.

GCC can take advantage of this, assuming that other portions of the
location are unchanged, leading to a number of potential problems.

This is similar to what we fixed back in commit:

  fee960b ("arm64: xchg: hazard against entire exchange variable")

... but we forgot to adjust cmpxchg_double*() similarly at the same
time.

The same problem applies, as demonstrated with the following test:

| struct big {
|         u64 lo, hi;
| } __aligned(128);
|
| unsigned long foo(struct big *b)
| {
|         u64 hi_old, hi_new;
|
|         hi_old = b->hi;
|         cmpxchg_double_local(&b->lo, &b->hi, 0x12, 0x34, 0x56, 0x78);
|         hi_new = b->hi;
|
|         return hi_old ^ hi_new;
| }

... which GCC 12.1.0 compiles as:

| 0000000000000000 <foo>:
|    0:   d503233f        paciasp
|    4:   aa0003e4        mov     x4, x0
|    8:   1400000e        b       40 <foo+0x40>
|    c:   d2800240        mov     x0, #0x12                       // #18
|   10:   d2800681        mov     x1, #0x34                       // #52
|   14:   aa0003e5        mov     x5, x0
|   18:   aa0103e6        mov     x6, x1
|   1c:   d2800ac2        mov     x2, #0x56                       // #86
|   20:   d2800f03        mov     x3, #0x78                       // #120
|   24:   48207c82        casp    x0, x1, x2, x3, [x4]
|   28:   ca050000        eor     x0, x0, x5
|   2c:   ca060021        eor     x1, x1, x6
|   30:   aa010000        orr     x0, x0, x1
|   34:   d2800000        mov     x0, #0x0                        // #0    <--- BANG
|   38:   d50323bf        autiasp
|   3c:   d65f03c0        ret
|   40:   d2800240        mov     x0, #0x12                       // #18
|   44:   d2800681        mov     x1, #0x34                       // #52
|   48:   d2800ac2        mov     x2, #0x56                       // #86
|   4c:   d2800f03        mov     x3, #0x78                       // #120
|   50:   f9800091        prfm    pstl1strm, [x4]
|   54:   c87f1885        ldxp    x5, x6, [x4]
|   58:   ca0000a5        eor     x5, x5, x0
|   5c:   ca0100c6        eor     x6, x6, x1
|   60:   aa0600a6        orr     x6, x5, x6
|   64:   b5000066        cbnz    x6, 70 <foo+0x70>
|   68:   c8250c82        stxp    w5, x2, x3, [x4]
|   6c:   35ffff45        cbnz    w5, 54 <foo+0x54>
|   70:   d2800000        mov     x0, #0x0                        // #0     <--- BANG
|   74:   d50323bf        autiasp
|   78:   d65f03c0        ret

Notice that at the lines with "BANG" comments, GCC has assumed that the
higher 8 bytes are unchanged by the cmpxchg_double() call, and that
`hi_old ^ hi_new` can be reduced to a constant zero, for both LSE and
LL/SC versions of cmpxchg_double().

This patch fixes the issue by passing a pointer to __uint128_t into the
+Q constraint, ensuring that the compiler hazards against the entire 16
bytes being modified.

With this change, GCC 12.1.0 compiles the above test as:

| 0000000000000000 <foo>:
|    0:   f9400407        ldr     x7, [x0, #8]
|    4:   d503233f        paciasp
|    8:   aa0003e4        mov     x4, x0
|    c:   1400000f        b       48 <foo+0x48>
|   10:   d2800240        mov     x0, #0x12                       // #18
|   14:   d2800681        mov     x1, #0x34                       // #52
|   18:   aa0003e5        mov     x5, x0
|   1c:   aa0103e6        mov     x6, x1
|   20:   d2800ac2        mov     x2, #0x56                       // #86
|   24:   d2800f03        mov     x3, #0x78                       // #120
|   28:   48207c82        casp    x0, x1, x2, x3, [x4]
|   2c:   ca050000        eor     x0, x0, x5
|   30:   ca060021        eor     x1, x1, x6
|   34:   aa010000        orr     x0, x0, x1
|   38:   f9400480        ldr     x0, [x4, #8]
|   3c:   d50323bf        autiasp
|   40:   ca0000e0        eor     x0, x7, x0
|   44:   d65f03c0        ret
|   48:   d2800240        mov     x0, #0x12                       // #18
|   4c:   d2800681        mov     x1, #0x34                       // #52
|   50:   d2800ac2        mov     x2, #0x56                       // #86
|   54:   d2800f03        mov     x3, #0x78                       // #120
|   58:   f9800091        prfm    pstl1strm, [x4]
|   5c:   c87f1885        ldxp    x5, x6, [x4]
|   60:   ca0000a5        eor     x5, x5, x0
|   64:   ca0100c6        eor     x6, x6, x1
|   68:   aa0600a6        orr     x6, x5, x6
|   6c:   b5000066        cbnz    x6, 78 <foo+0x78>
|   70:   c8250c82        stxp    w5, x2, x3, [x4]
|   74:   35ffff45        cbnz    w5, 5c <foo+0x5c>
|   78:   f9400480        ldr     x0, [x4, #8]
|   7c:   d50323bf        autiasp
|   80:   ca0000e0        eor     x0, x7, x0
|   84:   d65f03c0        ret

... sampling the high 8 bytes before and after the cmpxchg, and
performing an EOR, as we'd expect.

For backporting, I've tested this atop linux-4.9.y with GCC 5.5.0. Note
that linux-4.9.y is oldest currently supported stable release, and
mandates GCC 5.1+. Unfortunately I couldn't get a GCC 5.1 binary to run
on my machines due to library incompatibilities.

I've also used a standalone test to check that we can use a __uint128_t
pointer in a +Q constraint at least as far back as GCC 4.8.5 and LLVM
3.9.1.

Fixes: 5284e1b ("arm64: xchg: Implement cmpxchg_double")
Fixes: e9a4b79 ("arm64: cmpxchg_dbl: patch in lse instructions when supported by the CPU")
Reported-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/lkml/Y6DEfQXymYVgL3oJ@boqun-archlinux/
Reported-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/Y6GXoO4qmH9OIZ5Q@hirez.programming.kicks-ass.net/
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230104151626.3262137-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Sep 4, 2025
When there are memory-only nodes (nodes without CPUs), these nodes are not
properly initialized, causing kernel panic during boot.

of_numa_init
	of_numa_parse_cpu_nodes
		node_set(nid, numa_nodes_parsed);
	of_numa_parse_memory_nodes

In of_numa_parse_cpu_nodes, numa_nodes_parsed gets updated only for nodes
containing CPUs.  Memory-only nodes should have been updated in
of_numa_parse_memory_nodes, but they weren't.

Subsequently, when free_area_init() attempts to access NODE_DATA() for
these uninitialized memory nodes, the kernel panics due to NULL pointer
dereference.

This can be reproduced on ARM64 QEMU with 1 CPU and 2 memory nodes:

qemu-system-aarch64 \
-cpu host -nographic \
-m 4G -smp 1 \
-machine virt,accel=kvm,gic-version=3,iommu=smmuv3 \
-object memory-backend-ram,size=2G,id=mem0 \
-object memory-backend-ram,size=2G,id=mem1 \
-numa node,nodeid=0,memdev=mem0 \
-numa node,nodeid=1,memdev=mem1 \
-kernel $IMAGE \
-hda $DISK \
-append "console=ttyAMA0 root=/dev/vda rw earlycon"

[    0.000000] Booting Linux on physical CPU 0x0000000000 [0x481fd010]
[    0.000000] Linux version 6.17.0-rc1-00001-gabb4b3daf18c-dirty (yintirui@local) (gcc (GCC) 12.3.1, GNU ld (GNU Binutils) 2.41) kernel-patches#52 SMP PREEMPT Mon Aug 18 09:49:40 CST 2025
[    0.000000] KASLR enabled
[    0.000000] random: crng init done
[    0.000000] Machine model: linux,dummy-virt
[    0.000000] efi: UEFI not found.
[    0.000000] earlycon: pl11 at MMIO 0x0000000009000000 (options '')
[    0.000000] printk: legacy bootconsole [pl11] enabled
[    0.000000] OF: reserved mem: Reserved memory: No reserved-memory node in the DT
[    0.000000] NODE_DATA(0) allocated [mem 0xbfffd9c0-0xbfffffff]
[    0.000000] node 1 must be removed before remove section 23
[    0.000000] Zone ranges:
[    0.000000]   DMA      [mem 0x0000000040000000-0x00000000ffffffff]
[    0.000000]   DMA32    empty
[    0.000000]   Normal   [mem 0x0000000100000000-0x000000013fffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000040000000-0x00000000bfffffff]
[    0.000000]   node   1: [mem 0x00000000c0000000-0x000000013fffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000040000000-0x00000000bfffffff]
[    0.000000] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a0
[    0.000000] Mem abort info:
[    0.000000]   ESR = 0x0000000096000004
[    0.000000]   EC = 0x25: DABT (current EL), IL = 32 bits
[    0.000000]   SET = 0, FnV = 0
[    0.000000]   EA = 0, S1PTW = 0
[    0.000000]   FSC = 0x04: level 0 translation fault
[    0.000000] Data abort info:
[    0.000000]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[    0.000000]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[    0.000000]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[    0.000000] [00000000000000a0] user address but active_mm is swapper
[    0.000000] Internal error: Oops: 0000000096000004 [kernel-patches#1]  SMP
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.17.0-rc1-00001-g760c6dabf762-dirty kernel-patches#54 PREEMPT
[    0.000000] Hardware name: linux,dummy-virt (DT)
[    0.000000] pstate: 800000c5 (Nzcv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    0.000000] pc : free_area_init+0x50c/0xf9c
[    0.000000] lr : free_area_init+0x5c0/0xf9c
[    0.000000] sp : ffffa02ca0f33c00
[    0.000000] x29: ffffa02ca0f33cb0 x28: 0000000000000000 x27: 0000000000000000
[    0.000000] x26: 4ec4ec4ec4ec4ec5 x25: 00000000000c0000 x24: 00000000000c0000
[    0.000000] x23: 0000000000040000 x22: 0000000000000000 x21: ffffa02ca0f3b368
[    0.000000] x20: ffffa02ca14c7b98 x19: 0000000000000000 x18: 0000000000000002
[    0.000000] x17: 000000000000cacc x16: 0000000000000001 x15: 0000000000000001
[    0.000000] x14: 0000000080000000 x13: 0000000000000018 x12: 0000000000000002
[    0.000000] x11: ffffa02ca0fd4f00 x10: ffffa02ca14bab20 x9 : ffffa02ca14bab38
[    0.000000] x8 : 00000000000c0000 x7 : 0000000000000001 x6 : 0000000000000002
[    0.000000] x5 : 0000000140000000 x4 : ffffa02ca0f33c90 x3 : ffffa02ca0f33ca0
[    0.000000] x2 : ffffa02ca0f33c98 x1 : 0000000080000000 x0 : 0000000000000001
[    0.000000] Call trace:
[    0.000000]  free_area_init+0x50c/0xf9c (P)
[    0.000000]  bootmem_init+0x110/0x1dc
[    0.000000]  setup_arch+0x278/0x60c
[    0.000000]  start_kernel+0x70/0x748
[    0.000000]  __primary_switched+0x88/0x90
[    0.000000] Code: d503201f b98093e0 52800016 f8607a93 (f9405260)
[    0.000000] ---[ end trace 0000000000000000 ]---
[    0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
[    0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---

Link: https://lkml.kernel.org/r/20250819075510.2079961-1-yintirui@huawei.com
Fixes: 7675076 ("arch_numa: switch over to numa_memblks")
Signed-off-by: Yin Tirui <yintirui@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Chen Jun <chenjun102@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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