* [akpm-mm:mm-new] BUILD SUCCESS WITH UNVERIFIED WARNING 0c39e2f552f5e16be695cec3a1c77d6a6bf086bb
@ 2026-07-31 14:31 kernel test robot
2026-07-31 17:05 ` Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: kernel test robot @ 2026-07-31 14:31 UTC (permalink / raw)
To: David Hildenbrand; +Cc: Andrew Morton, Linux Memory Management List, mm-commits
tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-new
branch HEAD: 0c39e2f552f5e16be695cec3a1c77d6a6bf086bb mm/swap, PM: hibernate: atomically replace hibernation pin
Unverified Warning (likely false positive, kindly check if interested):
https://lore.kernel.org/oe-kbuild/202607120402.clBrrZQA-lkp@intel.com
mm/hmm.c:673 hmm_do_fault() error: we previously assumed 'hmm_vma_walk->locked' could be null (see line 654)
Warning ids grouped by kconfigs:
recent_errors
`-- powerpc64-randconfig-r072-20260731
`-- mm-hmm.c-hmm_do_fault()-error:we-previously-assumed-hmm_vma_walk-locked-could-be-null-(see-line-)
elapsed time: 795m
configs tested: 150
configs skipped: 1
tested configs:
alpha allnoconfig gcc-16.1.0
alpha allyesconfig gcc-16.1.0
alpha defconfig gcc-16.1.0
arc allmodconfig gcc-16.1.0
arc allyesconfig gcc-16.1.0
arc randconfig-001-20260731 clang-17
arc randconfig-001-20260731 gcc-8.5.0
arc randconfig-002-20260731 clang-17
arc randconfig-002-20260731 gcc-16.1.0
arm randconfig-001-20260731 clang-17
arm randconfig-002-20260731 clang-17
arm randconfig-002-20260731 clang-19
arm randconfig-003-20260731 clang-17
arm randconfig-003-20260731 clang-24
arm randconfig-004-20260731 clang-17
arm randconfig-004-20260731 clang-24
arm64 randconfig-001-20260731 gcc-8.5.0
arm64 randconfig-002-20260731 clang-24
arm64 randconfig-002-20260731 gcc-8.5.0
arm64 randconfig-003-20260731 gcc-10.5.0
arm64 randconfig-003-20260731 gcc-8.5.0
arm64 randconfig-004-20260731 gcc-12.5.0
arm64 randconfig-004-20260731 gcc-8.5.0
csky allmodconfig gcc-16.1.0
csky randconfig-001-20260731 gcc-16.1.0
csky randconfig-001-20260731 gcc-8.5.0
csky randconfig-002-20260731 gcc-10.5.0
csky randconfig-002-20260731 gcc-8.5.0
hexagon randconfig-001-20260731 clang-24
hexagon randconfig-002-20260731 clang-24
i386 allmodconfig gcc-14
i386 buildonly-randconfig-001-20260731 clang-22
i386 buildonly-randconfig-001-20260731 gcc-14
i386 buildonly-randconfig-002-20260731 clang-22
i386 buildonly-randconfig-003-20260731 clang-22
i386 buildonly-randconfig-004-20260731 clang-22
i386 buildonly-randconfig-004-20260731 gcc-13
i386 buildonly-randconfig-005-20260731 clang-22
i386 buildonly-randconfig-006-20260731 clang-22
i386 buildonly-randconfig-006-20260731 gcc-14
i386 randconfig-001-20260731 gcc-14
i386 randconfig-002-20260731 clang-22
i386 randconfig-002-20260731 gcc-14
i386 randconfig-003-20260731 clang-22
i386 randconfig-003-20260731 gcc-14
i386 randconfig-004-20260731 gcc-14
i386 randconfig-005-20260731 gcc-14
i386 randconfig-006-20260731 gcc-13
i386 randconfig-006-20260731 gcc-14
i386 randconfig-007-20260731 gcc-14
i386 randconfig-011-20260731 clang-22
i386 randconfig-012-20260731 clang-22
i386 randconfig-013-20260731 clang-22
i386 randconfig-013-20260731 gcc-14
i386 randconfig-014-20260731 clang-22
i386 randconfig-014-20260731 gcc-14
i386 randconfig-015-20260731 clang-22
i386 randconfig-015-20260731 gcc-14
i386 randconfig-016-20260731 clang-22
i386 randconfig-016-20260731 gcc-14
i386 randconfig-017-20260731 clang-22
i386 randconfig-017-20260731 gcc-14
loongarch defconfig clang-24
loongarch randconfig-001-20260731 clang-24
loongarch randconfig-001-20260731 gcc-16.1.0
loongarch randconfig-002-20260731 clang-24
mips decstation_r4k_defconfig gcc-16.1.0
nios2 allmodconfig gcc-11.5.0
nios2 allnoconfig gcc-11.5.0
nios2 randconfig-001-20260731 clang-24
nios2 randconfig-001-20260731 gcc-8.5.0
nios2 randconfig-002-20260731 clang-24
nios2 randconfig-002-20260731 gcc-8.5.0
parisc allmodconfig gcc-16.1.0
parisc allyesconfig gcc-16.1.0
parisc defconfig gcc-16.1.0
parisc randconfig-001 gcc-8.5.0
parisc randconfig-001-20260731 gcc-8.5.0
parisc randconfig-002-20260731 gcc-13.4.0
parisc randconfig-002-20260731 gcc-8.5.0
powerpc randconfig-001-20260731 clang-17
powerpc randconfig-001-20260731 gcc-8.5.0
powerpc randconfig-002-20260731 clang-24
powerpc randconfig-002-20260731 gcc-8.5.0
powerpc64 randconfig-001-20260731 gcc-8.5.0
powerpc64 randconfig-002-20260731 gcc-8.5.0
riscv randconfig-001-20260731 clang-19
riscv randconfig-002-20260731 clang-19
riscv randconfig-002-20260731 gcc-12.5.0
s390 randconfig-001-20260731 clang-19
s390 randconfig-001-20260731 clang-24
s390 randconfig-002-20260731 clang-19
s390 randconfig-002-20260731 clang-21
sh defconfig gcc-16.1.0
sh randconfig-001-20260731 clang-19
sh randconfig-001-20260731 gcc-16.1.0
sh randconfig-002-20260731 clang-19
sh randconfig-002-20260731 gcc-16.1.0
sparc randconfig-001 gcc-14
sparc randconfig-001-20260731 gcc-13.4.0
sparc randconfig-001-20260731 gcc-14
sparc randconfig-002-20260731 gcc-14
sparc randconfig-002-20260731 gcc-8.5.0
sparc64 randconfig-001-20260731 clang-20
sparc64 randconfig-001-20260731 gcc-14
sparc64 randconfig-002-20260731 gcc-14
sparc64 randconfig-002-20260731 gcc-8.5.0
um randconfig-001-20260731 gcc-14
um randconfig-002-20260731 gcc-14
x86_64 buildonly-randconfig-001-20260731 clang-22
x86_64 buildonly-randconfig-001-20260731 gcc-14
x86_64 buildonly-randconfig-002-20260731 clang-22
x86_64 buildonly-randconfig-002-20260731 gcc-14
x86_64 buildonly-randconfig-003-20260731 clang-22
x86_64 buildonly-randconfig-003-20260731 gcc-14
x86_64 buildonly-randconfig-004-20260731 clang-22
x86_64 buildonly-randconfig-004-20260731 gcc-14
x86_64 buildonly-randconfig-005-20260731 clang-22
x86_64 buildonly-randconfig-005-20260731 gcc-14
x86_64 buildonly-randconfig-006-20260731 gcc-14
x86_64 kexec clang-22
x86_64 randconfig-001-20260731 clang-22
x86_64 randconfig-001-20260731 gcc-14
x86_64 randconfig-002-20260731 gcc-14
x86_64 randconfig-003-20260731 gcc-14
x86_64 randconfig-004-20260731 gcc-14
x86_64 randconfig-005-20260731 clang-22
x86_64 randconfig-005-20260731 gcc-14
x86_64 randconfig-006-20260731 clang-22
x86_64 randconfig-006-20260731 gcc-14
x86_64 randconfig-011-20260731 clang-22
x86_64 randconfig-012-20260731 gcc-14
x86_64 randconfig-013-20260731 clang-22
x86_64 randconfig-014-20260731 clang-22
x86_64 randconfig-015-20260731 gcc-14
x86_64 randconfig-016-20260731 gcc-14
x86_64 randconfig-071-20260731 clang-22
x86_64 randconfig-071-20260731 gcc-14
x86_64 randconfig-072-20260731 clang-22
x86_64 randconfig-073-20260731 clang-22
x86_64 randconfig-074-20260731 clang-22
x86_64 randconfig-074-20260731 gcc-14
x86_64 randconfig-075-20260731 clang-22
x86_64 randconfig-075-20260731 gcc-14
x86_64 randconfig-076-20260731 clang-22
x86_64 rhel-9.4-bpf gcc-14
xtensa randconfig-001-20260731 gcc-14
xtensa randconfig-001-20260731 gcc-9.5.0
xtensa randconfig-002-20260731 gcc-11.5.0
xtensa randconfig-002-20260731 gcc-14
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [akpm-mm:mm-new] BUILD SUCCESS WITH UNVERIFIED WARNING 0c39e2f552f5e16be695cec3a1c77d6a6bf086bb
2026-07-31 14:31 [akpm-mm:mm-new] BUILD SUCCESS WITH UNVERIFIED WARNING 0c39e2f552f5e16be695cec3a1c77d6a6bf086bb kernel test robot
@ 2026-07-31 17:05 ` Andrew Morton
2026-07-31 18:40 ` Stanislav Kinsburskii
0 siblings, 1 reply; 3+ messages in thread
From: Andrew Morton @ 2026-07-31 17:05 UTC (permalink / raw)
To: kernel test robot
Cc: David Hildenbrand, Linux Memory Management List, mm-commits,
Stanislav Kinsburskii
On Fri, 31 Jul 2026 22:31:38 +0800 kernel test robot <lkp@intel.com> wrote:
> tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-new
> branch HEAD: 0c39e2f552f5e16be695cec3a1c77d6a6bf086bb mm/swap, PM: hibernate: atomically replace hibernation pin
>
> Unverified Warning (likely false positive, kindly check if interested):
>
> https://lore.kernel.org/oe-kbuild/202607120402.clBrrZQA-lkp@intel.com
>
> mm/hmm.c:673 hmm_do_fault() error: we previously assumed 'hmm_vma_walk->locked' could be null (see line 654)
Thanks, due to "mm/hmm: add hmm_range_fault_unlocked_timeout() for mmap
lock-drop support". I think we've looked at this previously.
+ if (hmm_vma_walk->locked)
+ fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
...
+ *hmm_vma_walk->locked = false;
Stanislav, can you please take a look?
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [akpm-mm:mm-new] BUILD SUCCESS WITH UNVERIFIED WARNING 0c39e2f552f5e16be695cec3a1c77d6a6bf086bb
2026-07-31 17:05 ` Andrew Morton
@ 2026-07-31 18:40 ` Stanislav Kinsburskii
0 siblings, 0 replies; 3+ messages in thread
From: Stanislav Kinsburskii @ 2026-07-31 18:40 UTC (permalink / raw)
To: Andrew Morton
Cc: kernel test robot, David Hildenbrand,
Linux Memory Management List, mm-commits
On Fri, Jul 31, 2026 at 10:05:47AM -0700, Andrew Morton wrote:
> On Fri, 31 Jul 2026 22:31:38 +0800 kernel test robot <lkp@intel.com> wrote:
>
> > tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-new
> > branch HEAD: 0c39e2f552f5e16be695cec3a1c77d6a6bf086bb mm/swap, PM: hibernate: atomically replace hibernation pin
> >
> > Unverified Warning (likely false positive, kindly check if interested):
> >
> > https://lore.kernel.org/oe-kbuild/202607120402.clBrrZQA-lkp@intel.com
> >
> > mm/hmm.c:673 hmm_do_fault() error: we previously assumed 'hmm_vma_walk->locked' could be null (see line 654)
>
> Thanks, due to "mm/hmm: add hmm_range_fault_unlocked_timeout() for mmap
> lock-drop support". I think we've looked at this previously.
>
> + if (hmm_vma_walk->locked)
> + fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
>
> ...
>
> + *hmm_vma_walk->locked = false;
>
> Stanislav, can you please take a look?
It's the same concern as before: this path can be triggered only by a buggy fault
handler.
The logic in hmm_range_fault_unlocked_timeout() mimics the same login in
GUP's fixup_user_fault().
A quote from one of my previous emails:
"Fault handlers are not supposed to return VM_FAULT_RETRY or
VM_FAULT_COMPLETED with the mmap lock dropped unless
FAULT_FLAG_ALLOW_RETRY allows that, so the NULL locked state is not
expected to be dereferenced"
Thanks,
Stanisav
^ permalink raw reply [flat|nested] 3+ messages in thread
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2026-07-31 14:31 [akpm-mm:mm-new] BUILD SUCCESS WITH UNVERIFIED WARNING 0c39e2f552f5e16be695cec3a1c77d6a6bf086bb kernel test robot
2026-07-31 17:05 ` Andrew Morton
2026-07-31 18:40 ` Stanislav Kinsburskii
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