 ftrace event structures are packed. The
function graph exit event structures are one of them. The 64 bit calltime
and rettime fields end up 4 byte aligned, but the algorithm to show to
userspace shows them as 8 byte aligned.

The macros that create the ftrace events has one for embedded structure
fields. There's two macros for theses fields:

  __field_desc() and __field_packed()

The difference of the latter macro is that it treats the field as packed.

Rename that field to __field_desc_packed() and create replace the
__field_packed() to be a normal field that is packed and have the calltime
and rettime use those.

This showed up on 32bit architectures for function graph time fields. It
had:

 ~# cat /sys/kernel/tracing/events/ftrace/funcgraph_exit/format
[..]
        field:unsigned long func;       offset:8;       size:4; signed:0;
        field:unsigned int depth;       offset:12;      size:4; signed:0;
        field:unsigned int overrun;     offset:16;      size:4; signed:0;
        field:unsigned long long calltime;      offset:24;      size:8; signed:0;
        field:unsigned long long rettime;       offset:32;      size:8; signed:0;

Notice that overrun is at offset 16 with size 4, where in the structure
calltime is at offset 20 (16 + 4), but it shows the offset at 24. That's
because it used the alignment of unsigned long long when used as a
declaration and not as a member of a structure where it would be aligned
by word size (in this case 4).

By using the proper structure alignment, the format has it at the correct
offset:

 ~# cat /sys/kernel/tracing/events/ftrace/funcgraph_exit/format
[..]
        field:unsigned long func;       offset:8;       size:4; signed:0;
        field:unsigned int depth;       offset:12;      size:4; signed:0;
        field:unsigned int overrun;     offset:16;      size:4; signed:0;
        field:unsigned long long calltime;      offset:20;      size:8; signed:0;
        field:unsigned long long rettime;       offset:28;      size:8; signed:0;

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reported-by: "jempty.liang" <imntjempty@163.com>
Link: https://patch.msgid.link/20260204113628.53faec78@gandalf.local.home
Fixes: 04ae87a52074e ("ftrace: Rework event_create_dir()")
Closes: https://lore.kernel.org/all/20260130015740.212343-1-imntjempty@163.com/
Closes: https://lore.kernel.org/all/20260202123342.2544795-1-imntjempty@163.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index b6d42fe06115..c11edec5d8f5 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -68,14 +68,17 @@ enum trace_type {
 #undef __field_fn
 #define __field_fn(type, item)		type	item;
 
+#undef __field_packed
+#define __field_packed(type, item)	type	item;
+
 #undef __field_struct
 #define __field_struct(type, item)	__field(type, item)
 
 #undef __field_desc
 #define __field_desc(type, container, item)
 
-#undef __field_packed
-#define __field_packed(type, container, item)
+#undef __field_desc_packed
+#define __field_desc_packed(type, container, item)
 
 #undef __array
 #define __array(type, item, size)	type	item[size];
diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index f6a8d29c0d76..54417468fdeb 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -79,8 +79,8 @@ FTRACE_ENTRY(funcgraph_entry, ftrace_graph_ent_entry,
 
 	F_STRUCT(
 		__field_struct(	struct ftrace_graph_ent,	graph_ent	)
-		__field_packed(	unsigned long,	graph_ent,	func		)
-		__field_packed(	unsigned long,	graph_ent,	depth		)
+		__field_desc_packed(unsigned long,	graph_ent,	func	)
+		__field_desc_packed(unsigned long,	graph_ent,	depth	)
 		__dynamic_array(unsigned long,	args				)
 	),
 
@@ -96,9 +96,9 @@ FTRACE_ENTRY_PACKED(fgraph_retaddr_entry, fgraph_retaddr_ent_entry,
 
 	F_STRUCT(
 		__field_struct(	struct fgraph_retaddr_ent,	graph_rent	)
-		__field_packed(	unsigned long,	graph_rent.ent,	func		)
-		__field_packed(	unsigned long,	graph_rent.ent,	depth		)
-		__field_packed(	unsigned long,	graph_rent,	retaddr		)
+		__field_desc_packed(	unsigned long,	graph_rent.ent,	func	)
+		__field_desc_packed(	unsigned long,	graph_rent.ent,	depth	)
+		__field_desc_packed(	unsigned long,	graph_rent,	retaddr	)
 		__dynamic_array(unsigned long,	args				)
 	),
 
@@ -123,12 +123,12 @@ FTRACE_ENTRY_PACKED(funcgraph_exit, ftrace_graph_ret_entry,
 
 	F_STRUCT(
 		__field_struct(	struct ftrace_graph_ret,	ret	)
-		__field_packed(	unsigned long,	ret,		func	)
-		__field_packed(	unsigned long,	ret,		retval	)
-		__field_packed(	unsigned int,	ret,		depth	)
-		__field_packed(	unsigned int,	ret,		overrun	)
-		__field(unsigned long long,	calltime		)
-		__field(unsigned long long,	rettime			)
+		__field_desc_packed(	unsigned long,	ret,	func	)
+		__field_desc_packed(	unsigned long,	ret,	retval	)
+		__field_desc_packed(	unsigned int,	ret,	depth	)
+		__field_desc_packed(	unsigned int,	ret,	overrun	)
+		__field_packed(unsigned long long,	calltime)
+		__field_packed(unsigned long long,	rettime	)
 	),
 
 	F_printk("<-- %ps (%u) (start: %llx  end: %llx) over: %u retval: %lx",
@@ -146,11 +146,11 @@ FTRACE_ENTRY_PACKED(funcgraph_exit, ftrace_graph_ret_entry,
 
 	F_STRUCT(
 		__field_struct(	struct ftrace_graph_ret,	ret	)
-		__field_packed(	unsigned long,	ret,		func	)
-		__field_packed(	unsigned int,	ret,		depth	)
-		__field_packed(	unsigned int,	ret,		overrun	)
-		__field(unsigned long long,	calltime		)
-		__field(unsigned long long,	rettime			)
+		__field_desc_packed(	unsigned long,	ret,	func	)
+		__field_desc_packed(	unsigned int,	ret,	depth	)
+		__field_desc_packed(	unsigned int,	ret,	overrun	)
+		__field_packed(unsigned long long,	calltime	)
+		__field_packed(unsigned long long,	rettime		)
 	),
 
 	F_printk("<-- %ps (%u) (start: %llx  end: %llx) over: %u",
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index 1698fc22afa0..32a42ef31855 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -42,11 +42,14 @@ static int ftrace_event_register(struct trace_event_call *call,
 #undef __field_fn
 #define __field_fn(type, item)				type item;
 
+#undef __field_packed
+#define __field_packed(type, item)			type item;
+
 #undef __field_desc
 #define __field_desc(type, container, item)		type item;
 
-#undef __field_packed
-#define __field_packed(type, container, item)		type item;
+#undef __field_desc_packed
+#define __field_desc_packed(type, container, item)	type item;
 
 #undef __array
 #define __array(type, item, size)			type item[size];
@@ -104,11 +107,14 @@ static void __always_unused ____ftrace_check_##name(void)		\
 #undef __field_fn
 #define __field_fn(_type, _item) __field_ext(_type, _item, FILTER_TRACE_FN)
 
+#undef __field_packed
+#define __field_packed(_type, _item) __field_ext_packed(_type, _item, FILTER_OTHER)
+
 #undef __field_desc
 #define __field_desc(_type, _container, _item) __field_ext(_type, _item, FILTER_OTHER)
 
-#undef __field_packed
-#define __field_packed(_type, _container, _item) __field_ext_packed(_type, _item, FILTER_OTHER)
+#undef __field_desc_packed
+#define __field_desc_packed(_type, _container, _item) __field_ext_packed(_type, _item, FILTER_OTHER)
 
 #undef __array
 #define __array(_type, _item, _len) {					\
@@ -146,11 +152,14 @@ static struct trace_event_fields ftrace_event_fields_##name[] = {	\
 #undef __field_fn
 #define __field_fn(type, item)
 
+#undef __field_packed
+#define __field_packed(type, item)
+
 #undef __field_desc
 #define __field_desc(type, container, item)
 
-#undef __field_packed
-#define __field_packed(type, container, item)
+#undef __field_desc_packed
+#define __field_desc_packed(type, container, item)
 
 #undef __array
 #define __array(type, item, len)FAILED: patch "[PATCH] tracing: Fix ftrace event field alignments" failed to apply to 6.1-stable tree<gregkh@linuxfoundation.org> undefinedrostedt@goodmis.org,imntjempty@163.com,mark.rutland@arm.com,mathieu.desnoyers@efficios.com,mhiramat@kernel.org undefined undefined undefined undefined undefined undefined