[PATCH 5/7] perf top: Fix SIGBUS on sparc64

Arnaldo Carvalho de Melo
2015-02-25T21:06:11Z

From: David Ahern <david.ahern@oracle.com>

perf-top is terminating due to SIGBUS on sparc64. git bisect points to:

commit 82396986032915c1572bfb74b224fcc2e4e8ba7c
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Mon Sep 8 13:26:35 2014 -0300

perf evlist: Refcount mmaps

We need to know how many fds are using a perf mmap via
PERF_EVENT_IOC_SET_OUTPUT, so that we can know when to ditch an mmap,
refcount it.

This commit added 'int refcnt' to struct perf_mmap and the addition makes the
event_copy element no longer 8-byte aligned.

Fix by adding __attribute__((aligned(8))) to the event_copy struct
member.

Signed-off-by: David Ahern <david.ahern@oracle.com>
Link: http://lkml.kernel.org/r/1424304198-92028-1-git-send-email-david.ahern@oracle.com
[ Switched from 'int pad;' to using __attribute__, David tested/acked that ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/evlist.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index c94a9e03ecf1..e99a67632831 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -28,7 +28,7 @@ struct perf_mmap {
int mask;
int refcnt;
unsigned int prev;
- char event_copy[PERF_SAMPLE_MAX_SIZE];
+ char event_copy[PERF_SAMPLE_MAX_SIZE] __attribute__((aligned(8)));
};

struct perf_evlist {
--
1.9.3