Commit-ID: 8a1898db51a3390241cd5fae267dc8aaa9db0f8b Gitweb: http://git.kernel.org/tip/8a1898db51a3390241cd5fae267dc8aaa9db0f8b Author: Hendrik Brueckner <brueck...@linux.vnet.ibm.com> AuthorDate: Tue, 20 Jun 2017 12:26:39 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 21 Jun 2017 11:58:30 +0200
perf/aux: Correct return code of rb_alloc_aux() if !has_aux(ev) 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. Signed-off-by: Hendrik Brueckner <brueck...@linux.vnet.ibm.com> Acked-by: Alexander Shishkin <alexander.shish...@linux.intel.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Pu Hou <bjho...@linux.vnet.ibm.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Thomas-Mich Richter <tmri...@linux.vnet.ibm.com> Cc: a...@kernel.org Cc: linux-s...@vger.kernel.org Link: http://lkml.kernel.org/r/1497954399-6355-1-git-send-email-brueck...@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- 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) { /*
