[PATCH V4 0/4] arch: patch_text: Fixup last cpu should be master

From: guoren
Date: Thu Apr 07 2022 - 03:34:05 EST


From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>

These patch_text implementations are using stop_machine_cpuslocked
infrastructure with atomic cpu_count. The original idea: When the
master CPU patch_text, the others should wait for it. But current
implementation is using the first CPU as master, which couldn't
guarantee the remaining CPUs are waiting. This patch changes the
last CPU as the master to solve the potential risk.

Changes in v4:
- Add "Fixes:" for stable fixup
- Add cover letter for the patch series

Changes in v3:
- Separate the patch for different arch.

Changes in v2:
- Fixup num_online_cpus() - 1 is not last cpu

Guo Ren (4):
arm64: patch_text: Fixup last cpu should be master
riscv: patch_text: Fixup last cpu should be master
xtensa: patch_text: Fixup last cpu should be master
csky: patch_text: Fixup last cpu should be master

arch/arm64/kernel/patching.c | 4 ++--
arch/csky/kernel/probes/kprobes.c | 2 +-
arch/riscv/kernel/patch.c | 2 +-
arch/xtensa/kernel/jump_label.c | 2 +-
4 files changed, 5 insertions(+), 5 deletions(-)

--
2.25.1