linux/include/trace
Steven Rostedt (Google) 353e182012 tracing: Remove pointer (asterisk) and brackets from cpumask_t field
commit fab89a09c8 upstream.

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: 8230f27b1c ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2025-05-02 07:47:10 +02:00
..
events net/ipv4: add tracepoint for icmp_send 2025-03-07 16:56:44 +01:00
misc NFSD: add CB_RECALL_ANY tracepoints 2024-03-06 14:45:17 +00:00
stages tracing: Remove pointer (asterisk) and brackets from cpumask_t field 2025-05-02 07:47:10 +02:00
bpf_probe.h tracing: Add __cpumask to denote a trace event field that is a cpumask_t 2025-05-02 07:46:49 +02:00
define_custom_trace.h tracing: Add TRACE_CUSTOM_EVENT() macro 2022-03-11 11:49:24 -05:00
define_trace.h tracepoint: Optimize using static_call() 2020-09-01 09:58:06 +02:00
perf.h tracing: Add __cpumask to denote a trace event field that is a cpumask_t 2025-05-02 07:46:49 +02:00
syscall.h tracepoints: Migrate to use SYSCALL_WORK flag 2020-11-16 21:53:15 +01:00
trace_custom_events.h tracing: Rename the staging files for trace_events 2022-04-02 08:40:04 -04:00
trace_events.h tracing/ftrace: disable preemption in syscall probe 2024-12-14 19:54:45 +01:00