| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1332938158-5244-11-git-send-email-jolsa@redhat.com>
Date: Wed, 28 Mar 2012 14:35:53 +0200
From: Jiri Olsa <jolsa@...hat.com>
To: acme@...hat.com, a.p.zijlstra@...llo.nl, mingo@...e.hu,
paulus@...ba.org, cjashfor@...ux.vnet.ibm.com, fweisbec@...il.com
Cc: eranian@...gle.com, gorcunov@...nvz.org, tzanussi@...il.com,
mhiramat@...hat.com, rostedt@...dmis.org, robert.richter@....com,
fche@...hat.com, linux-kernel@...r.kernel.org,
Jiri Olsa <jolsa@...hat.com>
Subject: [PATCH 10/15] perf, tool: Back [vdso] DSO with real data
Storing data for VDSO shared object, because we need it for
the unwind process.
The idea is that VDSO shared object is same for all process
on a running system, so it makes no difference if we store
it inside the tracer - perf.
The record command:
When [vdso] map memory is hit, we retrieve [vdso] DSO image
and store it into temporary file. During the build-id
processing the [vdso] DSO image is stored as in build-id db,
and build-id refference is made inside perf.data. The temporary
file is removed when record is finished.
The report command:
We read build-id from perf.data and store [vdso] DSO object.
This object is refferenced and attached to map when the MMAP
events are processed. Thus during the SAMPLE event processing
we have correct mmap/dso attached.
Adding following functions for vdso object:
vdso__get_filename
- finds and store VDSO image into temp file,
the temp file path is returned
vdso__exit
- removes temporary VDSO image if there's any
Signed-off-by: Jiri Olsa <jolsa@...hat.com>
---
tools/perf/Makefile | 2 +
tools/perf/builtin-record.c | 3 +
tools/perf/util/map.c | 16 +++++++-
tools/perf/util/vdso.c | 92 +++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/vdso.h | 7 +++
5 files changed, 119 insertions(+), 1 deletions(-)
create mode 100644 tools/perf/util/vdso.c
create mode 100644 tools/perf/util/vdso.h
diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 2f42886..1097d1d 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -317,6 +317,7 @@ LIB_H += util/cpumap.h
LIB_H += util/top.h
LIB_H += $(ARCH_INCLUDE)
LIB_H += util/cgroup.h
+LIB_H += util/vdso.h
LIB_OBJS += $(OUTPUT)util/abspath.o
LIB_OBJS += $(OUTPUT)util/alias.o
@@ -378,6 +379,7 @@ LIB_OBJS += $(OUTPUT)util/util.o
LIB_OBJS += $(OUTPUT)util/xyarray.o
LIB_OBJS += $(OUTPUT)util/cpumap.o
LIB_OBJS += $(OUTPUT)util/cgroup.o
+LIB_OBJS += $(OUTPUT)util/vdso.o
BUILTIN_OBJS += $(OUTPUT)builtin-annotate.o
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index be4e1ee..7b98fa9 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -26,6 +26,7 @@
#include "util/symbol.h"
#include "util/cpumap.h"
#include "util/thread_map.h"
+#include "util/vdso.h"
#include <unistd.h>
#include <sched.h>
@@ -336,6 +337,7 @@ static void perf_record__exit(int status __used, void *arg)
perf_session__delete(rec->session);
perf_evlist__delete(rec->evlist);
symbol__exit();
+ vdso__exit();
}
}
@@ -924,5 +926,6 @@ out_free_fd:
perf_evlist__delete_maps(evsel_list);
out_symbol_exit:
symbol__exit();
+ vdso__exit();
return err;
}
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index dea6d1c..f47dd80 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -7,6 +7,7 @@
#include <stdio.h>
#include <unistd.h>
#include "map.h"
+#include "vdso.h"
const char *map_type__name[MAP__NR_TYPES] = {
[MAP__FUNCTION] = "Functions",
@@ -18,10 +19,14 @@ static inline int is_anon_memory(const char *filename)
return strcmp(filename, "//anon") == 0;
}
+static inline int is_vdso_memory(const char *filename)
+{
+ return !strcmp(filename, "[vdso]");
+}
+
static inline int is_no_dso_memory(const char *filename)
{
return !strcmp(filename, "[stack]") ||
- !strcmp(filename, "[vdso]") ||
!strcmp(filename, "[heap]");
}
@@ -63,6 +68,15 @@ struct map *map__new(struct list_head *dsos__list, u64 start, u64 len,
if (dso == NULL)
goto out_delete;
+ if (is_vdso_memory(filename) && !dso->has_build_id) {
+ char *vdso = vdso__get_filename();
+ if (vdso) {
+ dso__set_long_name(dso, vdso);
+ pgoff = 0;
+ } else
+ no_dso = 1;
+ }
+
map__init(self, type, start, start + len, pgoff, dso);
if (anon || no_dso) {
diff --git a/tools/perf/util/vdso.c b/tools/perf/util/vdso.c
new file mode 100644
index 0000000..62dcdd0
--- /dev/null
+++ b/tools/perf/util/vdso.c
@@ -0,0 +1,92 @@
+
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <linux/kernel.h>
+#include "vdso.h"
+#include "util.h"
+
+static const char vdso_path[] = "/tmp/perf-vdso.so";
+static bool vdso_found;
+
+static int find_vdso_map(void **start, void **end)
+{
+ FILE *maps;
+ char line[128];
+ int found = 0;
+
+ maps = fopen("/proc/self/maps", "r");
+ if (!maps) {
+ pr_err("vdso: cannot open maps\n");
+ return -1;
+ }
+
+ while (!found && fgets(line, sizeof(line), maps)) {
+ int m = -1;
+
+ /* We care only about private r-x mappings. */
+ if (2 != sscanf(line, "%p-%p r-xp %*x %*x:%*x %*u %n",
+ start, end, &m))
+ continue;
+ if (m < 0)
+ continue;
+
+ pr_debug("vdso: start %p, end %p\n", *start, *end);
+
+ if (!strncmp(&line[m], "[vdso]", 6))
+ found = 1;
+ }
+
+ fclose(maps);
+ return !found;
+}
+
+char *vdso__get_filename(void)
+{
+ char *vdso = NULL;
+ char *buf = NULL;
+ void *start, *end;
+
+ do {
+ int fd, size;
+
+ if (vdso_found) {
+ vdso = (char *) vdso_path;
+ break;
+ }
+
+ if (find_vdso_map(&start, &end))
+ break;
+
+ size = end - start;
+ buf = malloc(size);
+ if (!buf)
+ break;
+
+ memcpy(buf, start, size);
+
+ fd = open(vdso_path, O_CREAT|O_WRONLY|O_TRUNC, S_IRWXU);
+ if (fd < 0)
+ break;
+
+ if (size == write(fd, buf, size))
+ vdso = (char *) vdso_path;
+
+ close(fd);
+ } while (0);
+
+ if (buf)
+ free(buf);
+
+ vdso_found = (vdso != NULL);
+ return vdso;
+}
+
+void vdso__exit(void)
+{
+ if (vdso_found)
+ unlink(vdso_path);
+}
diff --git a/tools/perf/util/vdso.h b/tools/perf/util/vdso.h
new file mode 100644
index 0000000..188fa9f
--- /dev/null
+++ b/tools/perf/util/vdso.h
@@ -0,0 +1,7 @@
+#ifndef __VDSO__
+#define __VDSO__
+
+char *vdso__get_filename(void);
+void vdso__exit(void);
+
+#endif /* __VDSO__ */
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists