This is a note to let you know that I've just added the patch titled
rethook: use preempt_{disable, enable}_notrace in rethook_trampoline_handler
to the 6.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
rethook-use-preempt_-disable-enable-_notrace-in-rethook_trampoline_handler.patch
and it can be found in the queue-6.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From be243bacfb25f5219f2396d787408e8cf1301dd1 Mon Sep 17 00:00:00 2001
From: Ze Gao <zegao2021@xxxxxxxxx>
Date: Wed, 17 May 2023 11:45:06 +0800
Subject: rethook: use preempt_{disable, enable}_notrace in rethook_trampoline_handler
From: Ze Gao <zegao2021@xxxxxxxxx>
commit be243bacfb25f5219f2396d787408e8cf1301dd1 upstream.
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@xxxxxxxxxxx/
Fixes: 54ecbe6f1ed5 ("rethook: Add a generic return hook")
Signed-off-by: Ze Gao <zegao@xxxxxxxxxxx>
Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/trace/rethook.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/kernel/trace/rethook.c
+++ b/kernel/trace/rethook.c
@@ -288,7 +288,7 @@ unsigned long rethook_trampoline_handler
* 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
first = first->next;
rethook_recycle(rhn);
}
- preempt_enable();
+ preempt_enable_notrace();
return correct_ret_addr;
}
Patches currently in stable-queue which might be from zegao2021@xxxxxxxxx are
queue-6.3/rethook-fprobe-do-not-trace-rethook-related-functions.patch
queue-6.3/rethook-use-preempt_-disable-enable-_notrace-in-rethook_trampoline_handler.patch
