Re: [PATCH v1 4/4] selftests/mm: Add test about uprobe pte be orphan during vma merge

[Aishwarya <aishwarya.tcv@arm.com>]

Hi,

kselftest-mm test 'merge.handle_uprobe_upon_merged_vma' is failing
against mainline master v6.16-rc1 with Arm64 on Ampere Altra/TX2 in our
CI. The kernel was built using defconfig along with the additional
config fragment from:

  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/testing/selftests/mm/config

I understand the failure is already being discussed and is expected to be
addressed by including sys/syscall.h.Sharing this observation here 
for reference.

A bisect identified commit efe99fabeb11b030c89a7dc5a5e7a7558d0dc7ec as the
first bad commit. This was bisected against tag v6.16-rc1 from:

  https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git

This test passes on Linux version v6.15-13627-g119b1e61a769.

Failure log:

  7151 12:46:54.627936  # # #  RUN           merge.handle_uprobe_upon_merged_vma ...
  7152 12:46:54.639014  # # f /sys/bus/event_source/devices/uprobe/type
  7153 12:46:54.639306  # # fopen: No such file or directory
  7154 12:46:54.650451  # # # merge.c:473:handle_uprobe_upon_merged_vma:Expected read_sysfs("/sys/bus/event_source/devices/uprobe/type", &type) (1) == 0 (0)
  7155 12:46:54.650730  # # # handle_uprobe_upon_merged_vma: Test terminated by assertion
  7156 12:46:54.661750  # # #          FAIL  merge.handle_uprobe_upon_merged_vma
  7157 12:46:54.662030  # # not ok 8 merge.handle_uprobe_upon_merged_vma

Git bisection log:

git bisect start
# status: waiting for both good and bad commits
# good: [119b1e61a769aa98e68599f44721661a4d8c55f3] Merge tag 'riscv-for-linus-6.16-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
git bisect good 119b1e61a769aa98e68599f44721661a4d8c55f3
# status: waiting for bad commit, 1 good commit known
# bad: [19272b37aa4f83ca52bdf9c16d5d81bdd1354494] Linux 6.16-rc1
git bisect bad 19272b37aa4f83ca52bdf9c16d5d81bdd1354494
# bad: [b3154a6ff1f53b794c01096577700f35b1be9cc2] Merge tag 'sh-for-v6.16-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux
git bisect bad b3154a6ff1f53b794c01096577700f35b1be9cc2
# bad: [5b032cac622533631b8f9b7826498b7ce75001c6] Merge tag 'ubifs-for-linus-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs
git bisect bad 5b032cac622533631b8f9b7826498b7ce75001c6
# good: [2da20fd904f87f7bb31b79719bc3dda4093f8cdb] kernel/rcu/tree_stall: add /sys/kernel/rcu_stall_count
git bisect good 2da20fd904f87f7bb31b79719bc3dda4093f8cdb
# good: [d3c82f618a9c2b764b7651afe16594ffeb50ade9] Merge tag 'mm-hotfixes-stable-2025-06-06-16-02' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
git bisect good d3c82f618a9c2b764b7651afe16594ffeb50ade9
# bad: [efe99fabeb11b030c89a7dc5a5e7a7558d0dc7ec] selftests/mm: add test about uprobe pte be orphan during vma merge
git bisect bad efe99fabeb11b030c89a7dc5a5e7a7558d0dc7ec
# good: [2b12d06c37fd3a394376f42f026a7478d826ed63] mm: fix uprobe pte be overwritten when expanding vma
git bisect good 2b12d06c37fd3a394376f42f026a7478d826ed63
# good: [6fb6223347d5d9512875120267c117e7437f0db6] selftests/mm: extract read_sysfs and write_sysfs into vm_util
git bisect good 6fb6223347d5d9512875120267c117e7437f0db6
# first bad commit: [efe99fabeb11b030c89a7dc5a5e7a7558d0dc7ec] selftests/mm: add test about uprobe pte be orphan during vma merge

Thanks,
Aishwarya