armbian/linux-rockchip
0
0
Fork 0
mirror of https://github.com/armbian/linux-rockchip.git synced 2026-01-06 11:08:10 -08:00
Code Issues Packages Projects Releases Wiki Activity

arm64: patch_text: Fixup last cpu should be master

Browse Source 
commit 31a099dbd9 upstream.

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.

Fixes: ae16480785 ("arm64: introduce interfaces to hotpatch kernel and module code")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220407073323.743224-2-guoren@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Guo Ren
2022-04-07 15:33:20 +08:00
committed by Greg Kroah-Hartman
parent a044bca8ef
commit 8bb4168291
1 changed files with 2 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
arch/arm64/kernel/insn.c
View File

@@ -216,8 +216,8 @@ static int __kprobes aarch64_insn_patch_text_cb(void *arg)
int i, ret = 0;
struct aarch64_insn_patch *pp = arg;
/* The first CPU becomes master */
if (atomic_inc_return(&pp->cpu_count) == 1) {
/* The last CPU becomes master */
if (atomic_inc_return(&pp->cpu_count) == num_online_cpus()) {
for (i = 0; ret == 0 && i < pp->insn_cnt; i++)
ret = aarch64_insn_patch_text_nosync(pp->text_addrs[i],
pp->new_insns[i]);