From: Frederic Weisbecker <fweisbec@gmail.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: LKML <linux-kernel@vger.kernel.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Paul Mackerras <paulus@samba.org>,
Steven Rostedt <rostedt@goodmis.org>,
Tom Zanussi <tzanussi@gmail.com>,
Masami Hiramatsu <mhiramat@redhat.com>,
David Miller <davem@davemloft.net>
Subject: [PATCH 3/3] perf: Fix unaligned accesses while fetching trace values
Date: Thu, 20 May 2010 11:44:19 +0200 [thread overview]
Message-ID: <1274348659-15417-4-git-send-regression-fweisbec@gmail.com> (raw)
In-Reply-To: <1274348659-15417-1-git-send-regression-fweisbec@gmail.com>
Accessing trace values of an 8 size may end up in a segfault
on archs that can't deal with misaligned access, which is the
case for sparc 64. This is because PERF_SAMPLE_RAW are aligned
to 4 and not to 8.
Fix this on the macros that get the values of 8 size.
This fixes segfaults on perf tools in sparc 64.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: David Miller <davem@davemloft.net>
---
tools/perf/util/trace-event.h | 7 ++++++-
1 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/tools/perf/util/trace-event.h b/tools/perf/util/trace-event.h
index 406d452..b3e86b1 100644
--- a/tools/perf/util/trace-event.h
+++ b/tools/perf/util/trace-event.h
@@ -233,7 +233,12 @@ static inline unsigned long long __data2host8(unsigned long long data)
#define data2host2(ptr) __data2host2(*(unsigned short *)ptr)
#define data2host4(ptr) __data2host4(*(unsigned int *)ptr)
-#define data2host8(ptr) __data2host8(*(unsigned long long *)ptr)
+#define data2host8(ptr) ({ \
+ unsigned long long __val; \
+ \
+ memcpy(&__val, (ptr), sizeof(unsigned long long)); \
+ __data2host8(__val); \
+})
extern int header_page_ts_offset;
extern int header_page_ts_size;
--
1.6.2.3
next prev parent reply other threads:[~2010-05-20 9:44 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-20 9:44 [GIT PULL] perf fixes Frederic Weisbecker
2010-05-20 9:44 ` [PATCH 1/3] perf: Use read() instead of lseek() in trace_event_read.c:skip() Frederic Weisbecker
2010-05-20 9:44 ` [PATCH 2/3] perf: Comply with new rcu checks API Frederic Weisbecker
2010-05-20 9:44 ` Frederic Weisbecker [this message]
2010-05-20 12:40 ` [GIT PULL] perf fixes Ingo Molnar
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