Vinson reported build breakage with gcc 4.4 due to strict-aliasing.
CC util/annotate.o
cc1: warnings being treated as errors
util/annotate.c: In function ‘disasm__purge’:
linux-next/tools/include/linux/compiler.h:66: error: dereferencing
pointer ‘res.41’ does break strict-aliasing rules
The reason is READ_ONCE/WRITE_ONCE code we took from kernel sources. They
intentionaly break aliasing rules. While this is ok for kernel because it's
built with -fno-strict-aliasing, it breaks perf which is build with
-Wstrict-aliasing=3.
Using extra __may_alias__ type to allow aliasing in this case.
Reported-and-tested-by: Vinson Lee <vlee@twopensource.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Martin Liska <mliska@suse.cz>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rabin Vincent <rabin@rab.in>
Cc: linux-next@vger.kernel.org
Link: http://lkml.kernel.org/r/20151013085214.GB2705@krava.brq.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We need it to build rbtree.c after this cset:
commit d72da4a4d9
Author: Peter Zijlstra <peterz@infradead.org>
Date: Wed May 27 11:09:36 2015 +0930
rbtree: Make lockless searches non-fatal
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-qlnzhezv5ddwst0w9fydju0y@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To make it generally accessible by other tools/ projects, also will be
used in the tools/arch/*/include/asm/barrier.h files that are being
introduced now.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-qnjdqwu3vcnt14vqmr6wu788@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1389276059-8829-3-git-send-email-namhyung@kernel.org
[ Added the new header to tools/perf/MANIFEST ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So that it can be shared with others like libtraceevent.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1389276059-8829-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Jiri Olsa