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>
fab89a09c8