At 2026-02-04 00:20:40, "Steven Rostedt" <[email protected]> wrote:
>On Tue, 3 Feb 2026 09:30:18 -0500
>Steven Rostedt <[email protected]> wrote:
>
>> > On the 32-bit ARM platform, when _type is unsigned long long, the
>> > resulting align value is 8 instead of the expected 4.
>> > >
>>
>> 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
Yes, I've verified it and this patch works correctly on the 32-bit ARM platform.
>
>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)
