Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Wed, 14 Dec 2022 09:01:37 -0500 | From | Steven Rostedt <> | Subject | [for-next][PATCH 4/8] tracing: Remove pointer (asterisk) and brackets from cpumask_t field |
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From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
To differentiate between long arrays and cpumasks, the __cpumask() field was created. Part of the TRACE_EVENT() macros test if the type is signed or not by using the is_signed_type() macro. The __cpumask() field used the __dynamic_array() helper but because cpumask_t is a structure, it could not be used in the is_signed_type() macro as that would fail to build, so instead it passed in the pointer to cpumask_t.
Unfortunately, that creates in the format file:
field:__data_loc cpumask_t *[] mask; offset:36; size:4; signed:0;
Which looks like an array of pointers to cpumask_t and not a cpumask_t type, which is misleading to user space parsers.
Douglas Raillard pointed out that the "[]" are also misleading, as cpumask_t is not an array.
Since cpumask() hasn't been created yet, and the parsers currently fail on it (but will still produce the raw output), make it be:
field:__data_loc cpumask_t mask; offset:36; size:4; signed:0;
Which is the correct type of the field.
Then the parsers can be updated to handle this.
Link: https://lore.kernel.org/lkml/6dda5e1d-9416-b55e-88f3-31d148bc925f@arm.com/ Link: https://lore.kernel.org/linux-trace-kernel/20221212193814.0e3f1e43@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: 8230f27b1ccc ("tracing: Add __cpumask to denote a trace event field that is a cpumask_t") Reported-by: Douglas Raillard <douglas.raillard@arm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> --- include/trace/stages/stage4_event_fields.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/include/trace/stages/stage4_event_fields.h b/include/trace/stages/stage4_event_fields.h index f2990d22313c..affd541fd25e 100644 --- a/include/trace/stages/stage4_event_fields.h +++ b/include/trace/stages/stage4_event_fields.h @@ -47,7 +47,10 @@ #define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item, -1) #undef __cpumask -#define __cpumask(item) __dynamic_array(cpumask_t *, item, -1) +#define __cpumask(item) { \ + .type = "__data_loc cpumask_t", .name = #item, \ + .size = 4, .align = 4, \ + .is_signed = 0, .filter_type = FILTER_OTHER }, #undef __sockaddr #define __sockaddr(field, len) __dynamic_array(u8, field, len) @@ -68,7 +71,10 @@ #define __rel_bitmask(item, nr_bits) __rel_dynamic_array(unsigned long, item, -1) #undef __rel_cpumask -#define __rel_cpumask(item) __rel_dynamic_array(cpumask_t *, item, -1) +#define __rel_cpumask(item) { \ + .type = "__rel_loc cpumask_t", .name = #item, \ + .size = 4, .align = 4, \ + .is_signed = 0, .filter_type = FILTER_OTHER }, #undef __rel_sockaddr #define __rel_sockaddr(field, len) __rel_dynamic_array(u8, field, len) -- 2.35.1
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