Hendrik Brueckner 8a1898db51 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 <brueckner@linux.vnet.ibm.com>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pu Hou <bjhoupu@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Cc: acme@kernel.org
Cc: linux-s390@vger.kernel.org
Link: http://lkml.kernel.org/r/1497954399-6355-1-git-send-email-brueckner@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-21 11:58:30 +02:00
2017-05-08 17:15:12 -07:00
2017-06-19 22:19:37 +08:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 3.3 GiB
Languages
C 97.5%
Assembly 1%
Shell 0.6%
Python 0.3%
Makefile 0.3%