From c6567f642e20bcc79abed030f44be5b0d6da2ded Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 26 Nov 2009 05:35:41 +0100 Subject: [PATCH] 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 Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras Cc: Prasad LKML-Reference: <1259210142-5714-2-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 35df94e344f2..34a1b9d7633e 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -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); -- 2.34.1