Re: [PATCH v2] tracing: Fix funcgraph_exit calltime/rettime offset for 32-bit ARM
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2026-02-03 16:20:17
Also in:
lkml
Subsystem:
the rest, tracing · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
On Tue, 3 Feb 2026 09:30:18 -0500 Steven Rostedt [off-list ref] wrote:
quoted
On the 32-bit ARM platform, when _type is unsigned long long, the resulting align value is 8 instead of the expected 4.quoted
Are you saying this still doesn't work? That would be an issue because then it would have the same bugs with generic trace events which uses the same solution.
OK, so talking with others that know more about arm32 than I do, it can indeed still produce an 8 byte alignment. Anyway, I still want to fix it properly. Does this patch work for you? -- Steve
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)