Great, thanks!

Regards, Ze

On Wed, May 17, 2023 at 7:59 PM Masami Hiramatsu mhiramat@kernel.org wrote:

Hi Ze Gao,

On Wed, 17 May 2023 11:45:06 +0800 Ze Gao zegao2021@gmail.com wrote:

...

This patch replaces preempt_{disable, enable} with its corresponding notrace version in rethook_trampoline_handler so no worries about stack recursion or overflow introduced by preempt_count_{add, sub} under fprobe + rethook context.

Fixes: 54ecbe6f1ed5 ("rethook: Add a generic return hook") Signed-off-by: Ze Gao zegao@tencent.com Acked-by: Masami Hiramatsu (Google) mhiramat@kernel.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/linux-trace-kernel/20230516071830.8190-2-zegao@tence...

Note that you don't need to add Link tag of the previous version for each patch. I'll add it when I pick it :)

Thank you,

...

---

kernel/trace/rethook.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c index 32c3dfdb4d6a..60f6cb2b486b 100644 --- a/kernel/trace/rethook.c +++ b/kernel/trace/rethook.c @@ -288,7 +288,7 @@ unsigned long rethook_trampoline_handler(struct pt_regs *regs, * These loops must be protected from rethook_free_rcu() because those * are accessing 'rhn->rethook'. */

• preempt_disable();
  

• preempt_disable_notrace();
  
  /*
   * Run the handler on the shadow stack. Do not unlink the list here because
  

@@ -321,7 +321,7 @@ unsigned long rethook_trampoline_handler(struct pt_regs *regs, first = first->next; rethook_recycle(rhn); }

• preempt_enable();
  

• preempt_enable_notrace();
  
  return correct_ret_addr;
  

}

2.40.1

-- Masami Hiramatsu (Google) mhiramat@kernel.org