From: Guo Ren <guoren@linux.alibaba.com> stable inclusion from stable-v5.10.121 commit df7f0f8be3019816ce7e3085195a0e68d028c4e2 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 8c4d16471e2babe9bdfe41d6ef724526629696cb 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: 33e53ae1ce41 ("csky: Add kprobes supported") Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Acked-by: Xie XiuQi <xiexiuqi@huawei.com> --- arch/csky/kernel/probes/kprobes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/csky/kernel/probes/kprobes.c b/arch/csky/kernel/probes/kprobes.c index 589f090f48b9..556b9ba61ec0 100644 --- a/arch/csky/kernel/probes/kprobes.c +++ b/arch/csky/kernel/probes/kprobes.c @@ -28,7 +28,7 @@ static int __kprobes patch_text_cb(void *priv) struct csky_insn_patch *param = priv; unsigned int addr = (unsigned int)param->addr; - if (atomic_inc_return(¶m->cpu_count) == 1) { + if (atomic_inc_return(¶m->cpu_count) == num_online_cpus()) { *(u16 *) addr = cpu_to_le16(param->opcode); dcache_wb_range(addr, addr + 2); atomic_inc(¶m->cpu_count); -- 2.20.1