hw-breakpoints: Improve in-kernel event creation error granularity

In fail case, perf_event_create_kernel_counter() returns NULL
instead of an error, which doesn't help us to inform the user
about the origin of the problem from the outer most callers.
Often we can just return -EINVAL, which doesn't help anyone when
it's eventually about a memory allocation failure.

Then, this patch makes perf_event_create_kernel_counter() always
return a detailed error code.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
LKML-Reference: <1259210142-5714-2-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Frederic Weisbecker 2009-11-26 05:35:41 +01:00 committed by Ingo Molnar
parent d99be40aff
commit c6567f642e

View file

@ -4780,14 +4780,17 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
*/
ctx = find_get_context(pid, cpu);
if (IS_ERR(ctx))
return NULL;
if (IS_ERR(ctx)) {
err = PTR_ERR(ctx);
goto err_exit;
}
event = perf_event_alloc(attr, cpu, ctx, NULL,
NULL, callback, GFP_KERNEL);
err = PTR_ERR(event);
if (IS_ERR(event))
if (IS_ERR(event)) {
err = PTR_ERR(event);
goto err_put_context;
}
event->filp = NULL;
WARN_ON_ONCE(ctx->parent_ctx);
@ -4804,11 +4807,10 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
return event;
err_put_context:
if (err < 0)
put_ctx(ctx);
return NULL;
err_put_context:
put_ctx(ctx);
err_exit:
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);