This is a note to let you know that I've just added the patch titled
tracing: Increase trace array ref count on enable and filter files
to the 6.1-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:
tracing-increase-trace-array-ref-count-on-enable-and-filter-files.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f5ca233e2e66dc1c249bf07eefa37e34a6c9346a Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
Date: Wed, 6 Sep 2023 22:47:12 -0400
Subject: tracing: Increase trace array ref count on enable and filter files
From: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
commit f5ca233e2e66dc1c249bf07eefa37e34a6c9346a upstream.
When the trace event enable and filter files are opened, increment the
trace array ref counter, otherwise they can be accessed when the trace
array is being deleted. The ref counter keeps the trace array from being
deleted while those files are opened.
Link: https://lkml.kernel.org/r/20230907024803.456187066@xxxxxxxxxxx
Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@xxxxxxxxxx/
Cc: stable@xxxxxxxxxxxxxxx
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Fixes: 8530dec63e7b4 ("tracing: Add tracing_check_open_get_tr()")
Tested-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
Tested-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
Reported-by: Zheng Yejian <zhengyejian1@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/trace/trace.c | 27 +++++++++++++++++++++++++++
kernel/trace/trace.h | 2 ++
kernel/trace/trace_events.c | 6 ++++--
3 files changed, 33 insertions(+), 2 deletions(-)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4899,6 +4899,33 @@ int tracing_open_generic_tr(struct inode
return 0;
}
+/*
+ * The private pointer of the inode is the trace_event_file.
+ * Update the tr ref count associated to it.
+ */
+int tracing_open_file_tr(struct inode *inode, struct file *filp)
+{
+ struct trace_event_file *file = inode->i_private;
+ int ret;
+
+ ret = tracing_check_open_get_tr(file->tr);
+ if (ret)
+ return ret;
+
+ filp->private_data = inode->i_private;
+
+ return 0;
+}
+
+int tracing_release_file_tr(struct inode *inode, struct file *filp)
+{
+ struct trace_event_file *file = inode->i_private;
+
+ trace_array_put(file->tr);
+
+ return 0;
+}
+
static int tracing_mark_open(struct inode *inode, struct file *filp)
{
stream_open(inode, filp);
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -590,6 +590,8 @@ void tracing_reset_all_online_cpus(void)
void tracing_reset_all_online_cpus_unlocked(void);
int tracing_open_generic(struct inode *inode, struct file *filp);
int tracing_open_generic_tr(struct inode *inode, struct file *filp);
+int tracing_open_file_tr(struct inode *inode, struct file *filp);
+int tracing_release_file_tr(struct inode *inode, struct file *filp);
bool tracing_is_disabled(void);
bool tracer_tracing_is_on(struct trace_array *tr);
void tracer_tracing_on(struct trace_array *tr);
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -2101,9 +2101,10 @@ static const struct file_operations ftra
};
static const struct file_operations ftrace_enable_fops = {
- .open = tracing_open_generic,
+ .open = tracing_open_file_tr,
.read = event_enable_read,
.write = event_enable_write,
+ .release = tracing_release_file_tr,
.llseek = default_llseek,
};
@@ -2120,9 +2121,10 @@ static const struct file_operations ftra
};
static const struct file_operations ftrace_event_filter_fops = {
- .open = tracing_open_generic,
+ .open = tracing_open_file_tr,
.read = event_filter_read,
.write = event_filter_write,
+ .release = tracing_release_file_tr,
.llseek = default_llseek,
};
Patches currently in stable-queue which might be from rostedt@xxxxxxxxxxx are
queue-6.1/tracing-increase-trace-array-ref-count-on-enable-and-filter-files.patch
queue-6.1/tracefs-add-missing-lockdown-check-to-tracefs_create_dir.patch
queue-6.1/selftests-tracing-fix-to-unmount-tracefs-for-recover.patch
queue-6.1/tracing-have-event-inject-files-inc-the-trace-array-ref-count.patch
queue-6.1/tracing-have-current_trace-inc-the-trace-array-ref-count.patch
queue-6.1/tracing-have-option-files-inc-the-trace-array-ref-count.patch
queue-6.1/tracing-have-tracing_max_latency-inc-the-trace-array-ref-count.patch
