From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Hendrik Brueckner Subject: [PATCH] kernel/perf: correct return code of rb_alloc_aux() if !has_aux(ev) Date: Tue, 20 Jun 2017 12:26:39 +0200 Message-Id: <1497954399-6355-1-git-send-email-brueckner@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: peterz@infradead.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, Pu Hou , Thomas-Mich Richter List-ID: If the event for which an AUX area is about to be allocated, does not support setting up an AUX area, rb_alloc_aux() return -ENOTSUPP. This error condition is being returned unfiltered to the user space, and, for example, the perf tools fails with: failed to mmap with 524 (INTERNAL ERROR: strerror_r(524, 0x3fff497a1c8, 512)=22) This error can be easily seen with "perf record -m 128,256 -e cpu-clock". The 524 error code maps to -ENOTSUPP (in rb_alloc_aux()). The -ENOTSUPP error code shall be only used within the kernel. So the correct error code would then be -EOPNOTSUPP. With this commit, the perf tool then reports: failed to mmap with 95 (Operation not supported) which is more clear. Cc: Pu Hou Cc: Thomas-Mich Richter Signed-off-by: Hendrik Brueckner --- kernel/events/ring_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index 2831480..ee97196 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -580,7 +580,7 @@ int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event, int ret = -ENOMEM, max_order = 0; if (!has_aux(event)) - return -ENOTSUPP; + return -EOPNOTSUPP; if (event->pmu->capabilities & PERF_PMU_CAP_AUX_NO_SG) { /* -- 1.8.3.1