Thread (12 messages) 12 messages, 3 authors, 2023-05-16
STALE1118d
Revisions (2)
  1. v1 [diff vs current]
  2. v1 current

[PATCH 1/4] rethook: use preempt_{disable, enable}_notrace in rethook_trampoline_handler

From: Ze Gao <hidden>
Date: 2023-05-15 03:27:12
Also in: lkml
Subsystem: the rest, tracing · Maintainers: Linus Torvalds, Steven Rostedt, Masami Hiramatsu

This patch replace 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.

Signed-off-by: Ze Gao <redacted>
---
 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
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