This is a note to let you know that I've just added the patch titled
ftrace: Properly unset FTRACE_HASH_FL_MOD
to the 4.14-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:
ftrace-properly-unset-ftrace_hash_fl_mod.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0ce0638edf5ec83343302b884fa208179580700a Mon Sep 17 00:00:00 2001
From: Zheng Yejian <zhengyejian1@xxxxxxxxxx>
Date: Mon, 26 Sep 2022 15:20:08 +0000
Subject: ftrace: Properly unset FTRACE_HASH_FL_MOD
From: Zheng Yejian <zhengyejian1@xxxxxxxxxx>
commit 0ce0638edf5ec83343302b884fa208179580700a upstream.
When executing following commands like what document said, but the log
"#### all functions enabled ####" was not shown as expect:
1. Set a 'mod' filter:
$ echo 'write*:mod:ext3' > /sys/kernel/tracing/set_ftrace_filter
2. Invert above filter:
$ echo '!write*:mod:ext3' >> /sys/kernel/tracing/set_ftrace_filter
3. Read the file:
$ cat /sys/kernel/tracing/set_ftrace_filter
By some debugging, I found that flag FTRACE_HASH_FL_MOD was not unset
after inversion like above step 2 and then result of ftrace_hash_empty()
is incorrect.
Link: https://lkml.kernel.org/r/20220926152008.2239274-1-zhengyejian1@xxxxxxxxxx
Cc: <mingo@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 8c08f0d5c6fb ("ftrace: Have cached module filters be an active filter")
Signed-off-by: Zheng Yejian <zhengyejian1@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/trace/ftrace.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5128,8 +5128,12 @@ int ftrace_regex_release(struct inode *i
if (filter_hash) {
orig_hash = &iter->ops->func_hash->filter_hash;
- if (iter->tr && !list_empty(&iter->tr->mod_trace))
- iter->hash->flags |= FTRACE_HASH_FL_MOD;
+ if (iter->tr) {
+ if (list_empty(&iter->tr->mod_trace))
+ iter->hash->flags &= ~FTRACE_HASH_FL_MOD;
+ else
+ iter->hash->flags |= FTRACE_HASH_FL_MOD;
+ }
} else
orig_hash = &iter->ops->func_hash->notrace_hash;
Patches currently in stable-queue which might be from zhengyejian1@xxxxxxxxxx are
queue-4.14/ftrace-properly-unset-ftrace_hash_fl_mod.patch
