[linus:master] [fs] 541d4c798a: BUG:KCSAN:data-race_in_atime_needs_update/inode_update_timestamps

Sun Apr 7 20:04:32 PDT 2024

Hello,

kernel test robot noticed "BUG:KCSAN:data-race_in_atime_needs_update/inode_update_timestamps" on:

commit: 541d4c798a598854fcce7326d947cbcbd35701d6 ("fs: drop the timespec64 arg from generic_update_time")
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master

in testcase: trinity
version: trinity-i386-abe9de86-1_20230429
with following parameters:

	runtime: 300s
	group: group-04
	nr_groups: 5

compiler: gcc-13
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G

(please refer to attached dmesg/kmsg for entire log/backtrace)

we noticed this issue does not always happen, and parent has similar ones.
we don't know if these issues are expected, just report what we found in our
tests FYI.

0d72b92883c651a1 541d4c798a598854fcce7326d94
---------------- ---------------------------
       fail:runs  %reproduction    fail:runs
           |             |             |
          8:202         -4%            :202   dmesg.BUG:KCSAN:data-race_in_atime_needs_update/generic_update_time
           :202         11%          22:202   dmesg.BUG:KCSAN:data-race_in_atime_needs_update/inode_update_timestamps
         48:202        -24%            :202   dmesg.BUG:KCSAN:data-race_in_atime_needs_update/touch_atime
           :202          7%          14:202   dmesg.BUG:KCSAN:data-race_in_generic_fillattr/inode_update_timestamps
         21:202        -10%            :202   dmesg.BUG:KCSAN:data-race_in_generic_fillattr/touch_atime
           :202         12%          24:202   dmesg.BUG:KCSAN:data-race_in_inode_update_timestamps/inode_update_timestamps

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang at intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202404081036.56aa7de3-lkp@intel.com

[  179.356355][ T3221] BUG: KCSAN: data-race in atime_needs_update / inode_update_timestamps
[  179.363113][ T3221]
[  179.363323][ T3221] write to 0xffffa34c4c66f600 of 8 bytes by task 3222 on cpu 0:
[ 179.363951][ T3221] inode_update_timestamps (fs/inode.c:1923) 
[ 179.364410][ T3221] generic_update_time (fs/inode.c:1948) 
[ 179.364823][ T3221] touch_atime (fs/inode.c:1966 fs/inode.c:2038) 
[ 179.365207][ T3221] generic_file_mmap (include/linux/fs.h:2245 mm/filemap.c:3616) 
[ 179.365721][ T3221] mmap_region (mm/mmap.c:2751) 
[ 179.366104][ T3221] do_mmap (mm/mmap.c:1362) 
[ 179.366448][ T3221] vm_mmap_pgoff (arch/x86/include/asm/jump_label.h:27 include/linux/jump_label.h:207 include/linux/mmap_lock.h:41 include/linux/mmap_lock.h:127 mm/util.c:545) 
[ 179.366840][ T3221] vm_mmap (mm/util.c:562) 
[ 179.367181][ T3221] elf_map (fs/binfmt_elf.c:378) 
[ 179.367586][ T3221] load_elf_binary (fs/binfmt_elf.c:1187) 
[ 179.367996][ T3221] search_binary_handler (fs/exec.c:1740) 
[ 179.368434][ T3221] exec_binprm (fs/exec.c:1781) 
[ 179.368813][ T3221] bprm_execve (fs/exec.c:279 fs/exec.c:383 fs/exec.c:1533) 
[ 179.369251][ T3221] bprm_execve (fs/exec.c:1885) 
[ 179.369784][ T3221] kernel_execve (fs/exec.c:2023) 
[ 179.370172][ T3221] call_usermodehelper_exec_async (kernel/umh.c:114) 
[ 179.370673][ T3221] ret_from_fork (arch/x86/entry/entry_64.S:314) 
[  179.371043][ T3221]
[  179.371253][ T3221] read to 0xffffa34c4c66f600 of 8 bytes by task 3221 on cpu 1:
[ 179.371864][ T3221] atime_needs_update (include/linux/time64.h:49 (discriminator 1) fs/inode.c:2008 (discriminator 1)) 
[ 179.372294][ T3221] touch_atime (fs/inode.c:2020 (discriminator 1)) 
[ 179.372669][ T3221] generic_file_mmap (include/linux/fs.h:2245 mm/filemap.c:3616) 
[ 179.373163][ T3221] mmap_region (mm/mmap.c:2751) 
[ 179.373533][ T3221] do_mmap (mm/mmap.c:1362) 
[ 179.373950][ T3221] vm_mmap_pgoff (arch/x86/include/asm/jump_label.h:27 include/linux/jump_label.h:207 include/linux/mmap_lock.h:41 include/linux/mmap_lock.h:127 mm/util.c:545) 
[ 179.374338][ T3221] vm_mmap (mm/util.c:562) 
[ 179.374673][ T3221] elf_map (fs/binfmt_elf.c:378) 
[ 179.375070][ T3221] load_elf_binary (fs/binfmt_elf.c:1187) 
[ 179.375498][ T3221] search_binary_handler (fs/exec.c:1740) 
[ 179.375941][ T3221] exec_binprm (fs/exec.c:1781) 
[ 179.376294][ T3221] bprm_execve (fs/exec.c:279 fs/exec.c:383 fs/exec.c:1533) 
[ 179.376712][ T3221] bprm_execve (fs/exec.c:1885) 
[ 179.377063][ T3221] kernel_execve (fs/exec.c:2023) 
[ 179.377452][ T3221] call_usermodehelper_exec_async (kernel/umh.c:114) 
[ 179.378061][ T3221] ret_from_fork (arch/x86/entry/entry_64.S:314) 
[  179.378434][ T3221]
[  179.378635][ T3221] value changed: 0x000000000402a3d1 -> 0x000000000411e611
[  179.379219][ T3221]
[  179.379411][ T3221] Reported by Kernel Concurrency Sanitizer on:
[  179.379920][ T3221] CPU: 1 PID: 3221 Comm: modprobe Tainted: G                 N 6.5.0-rc1-00096-g541d4c798a59 #1
[  179.380804][ T3221] ==================================================================

The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20240408/202404081036.56aa7de3-lkp@intel.com

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki