This is a note to let you know that I've just added the patch titled
tracing/synthetic: Fix order of struct trace_dynamic_info
to the 6.5-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-synthetic-fix-order-of-struct-trace_dynamic_info.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fc52a64416b010c8324e2cb50070faae868521c1 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
Date: Fri, 8 Sep 2023 16:39:29 -0400
Subject: tracing/synthetic: Fix order of struct trace_dynamic_info
From: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
commit fc52a64416b010c8324e2cb50070faae868521c1 upstream.
To make handling BIG and LITTLE endian better the offset/len of dynamic
fields of the synthetic events was changed into a structure of:
struct trace_dynamic_info {
#ifdef CONFIG_CPU_BIG_ENDIAN
u16 offset;
u16 len;
#else
u16 len;
u16 offset;
#endif
};
to replace the manual changes of:
data_offset = offset & 0xffff;
data_offest = len << 16;
But if you look closely, the above is:
<len> << 16 | offset
Which in little endian would be in memory:
offset_lo offset_hi len_lo len_hi
and in big endian:
len_hi len_lo offset_hi offset_lo
Which if broken into a structure would be:
struct trace_dynamic_info {
#ifdef CONFIG_CPU_BIG_ENDIAN
u16 len;
u16 offset;
#else
u16 offset;
u16 len;
#endif
};
Which is the opposite of what was defined.
Fix this and just to be safe also add "__packed".
Link: https://lore.kernel.org/all/20230908154417.5172e343@xxxxxxxxxxxxxxxxxx/
Link: https://lore.kernel.org/linux-trace-kernel/20230908163929.2c25f3dc@xxxxxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Tested-by: Sven Schnelle <svens@xxxxxxxxxxxxx>
Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Fixes: ddeea494a16f3 ("tracing/synthetic: Use union instead of casts")
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/trace_events.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 12f875e9e69a..21ae37e49319 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -62,13 +62,13 @@ void trace_event_printf(struct trace_iterator *iter, const char *fmt, ...);
/* Used to find the offset and length of dynamic fields in trace events */
struct trace_dynamic_info {
#ifdef CONFIG_CPU_BIG_ENDIAN
- u16 offset;
u16 len;
+ u16 offset;
#else
- u16 len;
u16 offset;
+ u16 len;
#endif
-};
+} __packed;
/*
* The trace entry - the most basic unit of tracing. This is what
--
2.42.0
Patches currently in stable-queue which might be from rostedt@xxxxxxxxxxx are
queue-6.5/tracing-increase-trace-array-ref-count-on-enable-and-filter-files.patch
queue-6.5/tracing-synthetic-print-out-u64-values-properly.patch
queue-6.5/tracefs-add-missing-lockdown-check-to-tracefs_create_dir.patch
queue-6.5/selftests-tracing-fix-to-unmount-tracefs-for-recover.patch
queue-6.5/tracing-have-event-inject-files-inc-the-trace-array-ref-count.patch
queue-6.5/tracing-have-current_trace-inc-the-trace-array-ref-count.patch
queue-6.5/tracing-synthetic-fix-order-of-struct-trace_dynamic_info.patch
queue-6.5/tracing-have-option-files-inc-the-trace-array-ref-count.patch
queue-6.5/tracing-have-tracing_max_latency-inc-the-trace-array-ref-count.patch
