Commit be243bac authored by Ze Gao's avatar Ze Gao Committed by Masami Hiramatsu (Google)
Browse files

rethook: use preempt_{disable, enable}_notrace in rethook_trampoline_handler 

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.

Link: https://lore.kernel.org/all/20230517034510.15639-2-zegao@tencent.com/



Fixes: 54ecbe6f ("rethook: Add a generic return hook")
Signed-off-by: default avatarZe Gao <zegao@tencent.com>
Acked-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
parent 6049674b

kernel/trace/rethook.c

+2 −2
Original line number Diff line number Diff line
@@ -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;

}