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perf, tools: Fix crash while reading old perf.data

PATCH In review Andi Kleen 3 participants 4 messages Nov 21, 2014 – Dec 8, 2014 perf events

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Andi Kleen

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#0 lore raw

PATCH 1/2 perf, tools: Fix crash while reading old perf.data

From: Andi Kleen <[email protected]>

In some cases when reading perf.data generated by much older perf I got segfaults with dso->long_name being zero. This patch fixes them for me.

Haven't tracked down the exact cause. I assume it's some error path that doesn't set it.

Signed-off-by Andi Kleen <[email protected]>
---
 tools/perf/util/machine.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
tools/perf/util/machine.c +1 -1
index 52e9490..6266041 100644
@@ -1106,7 +1106,7 @@ static int machine__process_kernel_mmap_event(struct machine *machine,
 		if (__machine__create_kernel_maps(machine, kernel) < 0)
 			goto out_problem;
 
-		if (strstr(dso->long_name, "vmlinux"))
+		if (dso->long_name && strstr(dso->long_name, "vmlinux"))
 			dso__set_short_name(dso, "[kernel.vmlinux]", false);
 
 		machine__set_kernel_mmap_len(machine, event);
Signature · 1 line
1.9.3
author
#1 lore raw

PATCH 2/2 perf, tools: Allow to force redirect pr_debug to stderr.

From: Andi Kleen <[email protected]>

When debugging the tui browser I find it useful to redirect the debug log into a file. Currently it's always forced to the message line.

Add an option to force it to stderr. Then it can be easily redirected.

Signed-off-by Andi Kleen <[email protected]>
---
 tools/perf/util/debug.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
tools/perf/util/debug.c +3 -1
index ba357f3..ad60b2f 100644
@@ -19,13 +19,14 @@
 int verbose;
 bool dump_trace = false, quiet = false;
 int debug_ordered_events;
+static int redirect_to_stderr;
 
 static int _eprintf(int level, int var, const char *fmt, va_list args)
 {
 	int ret = 0;
 
 	if (var >= level) {
-		if (use_browser >= 1)
+		if (use_browser >= 1 && !redirect_to_stderr)
 			ui_helpline__vshow(fmt, args);
 		else
 			ret = vfprintf(stderr, fmt, args);

@@ -145,6 +146,7 @@ static struct debug_variable {
 } debug_variables[] = {
 	{ .name = "verbose",		.ptr = &verbose },
 	{ .name = "ordered-events",	.ptr = &debug_ordered_events},
+	{ .name = "stderr",		.ptr = &redirect_to_stderr},
 	{ .name = NULL, }
 };
Signature · 1 line
1.9.3
merge bot
#2 lore raw

[tip:perf/core] perf tools: Allow to force redirect pr_debug to stderr.

perf tools: Allow to force redirect pr_debug to stderr.
Commit-ID:  f78eaef0e0493f6068777a246b9c4d9d5cf2b7aa
Gitweb:     http://git.kernel.org/tip/f78eaef0e0493f6068777a246b9c4d9d5cf2b7aa
Author:     Andi Kleen <[email protected]>
AuthorDate: Fri, 21 Nov 2014 13:38:00 -0800
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Mon, 24 Nov 2014 18:03:48 -0300

perf tools: Allow to force redirect pr_debug to stderr.

When debugging the tui browser I find it useful to redirect the debug log into a file. Currently it's always forced to the message line.

Add an option to force it to stderr. Then it can be easily redirected.

Example:

[root@zoo ~]# perf --debug stderr report -vv 2> /tmp/debug
[root@zoo ~]# tail /tmp/debug
dso open failed, mmap: No such file or directory
dso open failed, mmap: No such file or directory
dso open failed, mmap: No such file or directory
dso open failed, mmap: No such file or directory
dso open failed, mmap: No such file or directory
Using /root/.debug/.build-id/4e/841948927029fb650132253642d5dbb2c1fb93 for symbols Failed to open /tmp/perf-8831.map, continuing without symbols
Failed to open /tmp/perf-12721.map, continuing without symbols Failed to open /tmp/perf-6966.map, continuing without symbols
Failed to open /tmp/perf-8802.map, continuing without symbols [root@zoo ~]#

Signed-off-by Andi Kleen <[email protected]>
Cc Jiri Olsa <[email protected]>
Cc Namhyung Kim <[email protected]>
Link http://lkml.kernel.org/r/[email protected] open here
Signed-off-by Arnaldo Carvalho de Melo <[email protected]>
---
 tools/perf/util/debug.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
tools/perf/util/debug.c +3 -1
index ba357f3..ad60b2f 100644
@@ -19,13 +19,14 @@
 int verbose;
 bool dump_trace = false, quiet = false;
 int debug_ordered_events;
+static int redirect_to_stderr;
 
 static int _eprintf(int level, int var, const char *fmt, va_list args)
 {
 	int ret = 0;
 
 	if (var >= level) {
-		if (use_browser >= 1)
+		if (use_browser >= 1 && !redirect_to_stderr)
 			ui_helpline__vshow(fmt, args);
 		else
 			ret = vfprintf(stderr, fmt, args);

@@ -145,6 +146,7 @@ static struct debug_variable {
 } debug_variables[] = {
 	{ .name = "verbose",		.ptr = &verbose },
 	{ .name = "ordered-events",	.ptr = &debug_ordered_events},
+	{ .name = "stderr",		.ptr = &redirect_to_stderr},
 	{ .name = NULL, }
 };
#3 lore raw
In reply to Andi Kleen
Quoted 8 lines · Andi Kleen

From: Andi Kleen <[email protected]>

In some cases when reading perf.data generated by much older perf I got segfaults with dso->long_name being zero. This patch fixes them for me.

Haven't tracked down the exact cause. I assume it's some error path that doesn't set it.

Any chance this patch fixies it for you?
330dfa224fcc perf tools: Fix segfault due to invalid kernel dso access

it's on latest acme/perf/core

jirka

Quoted 22 lines
Signed-off-by Andi Kleen <[email protected]>
---
 tools/perf/util/machine.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
tools/perf/util/machine.c +1 -1
index 52e9490..6266041 100644
@@ -1106,7 +1106,7 @@ static int machine__process_kernel_mmap_event(struct machine *machine,
 		if (__machine__create_kernel_maps(machine, kernel) < 0)
 			goto out_problem;
 
-		if (strstr(dso->long_name, "vmlinux"))
+		if (dso->long_name && strstr(dso->long_name, "vmlinux"))
 			dso__set_short_name(dso, "[kernel.vmlinux]", false);
 
 		machine__set_kernel_mmap_len(machine, event);
Signature · 1 line
1.9.3