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

Commit Message

Ze Gao May 13, 2023, 8:16 a.m. UTC

This patch replace preempt_{disable, enable} with its corresponding
notrace version in rethook_trampoline_handler so worries about stack
recursion or overflow introduced by preempt_count_{add, sub} under
fprobe + rethook context.

Signed-off-by: Ze Gao <[e-mail]>
---
 kernel/trace/rethook.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Patch

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;
 }