[lttng-dev] [PATCH] Make base-address-state tracing use LD_PRELOAD
Paul Woegerer
paul_woegerer at mentor.com
Tue Nov 26 11:21:38 EST 2013
Signed-off-by: Paul Woegerer <paul_woegerer at mentor.com>
---
liblttng-ust-baddr/Makefile.am | 2 -
liblttng-ust-baddr/lttng-ust-baddr.c | 45 ++++---------
liblttng-ust-baddr/lttng-ust-baddr.h | 22 +++++++
liblttng-ust-dl/Makefile.am | 5 +-
.../ust_baddr.c | 0
.../ust_baddr.h | 0
liblttng-ust-dl/ustdl.c | 76 ++++++----------------
liblttng-ust/lttng-ust-comm.c | 43 +-----------
8 files changed, 62 insertions(+), 131 deletions(-)
create mode 100644 liblttng-ust-baddr/lttng-ust-baddr.h
rename {liblttng-ust-baddr => liblttng-ust-dl}/ust_baddr.c (100%)
rename {liblttng-ust-baddr => liblttng-ust-dl}/ust_baddr.h (100%)
diff --git a/liblttng-ust-baddr/Makefile.am b/liblttng-ust-baddr/Makefile.am
index 0d3cf28..23e4ce2 100644
--- a/liblttng-ust-baddr/Makefile.am
+++ b/liblttng-ust-baddr/Makefile.am
@@ -4,8 +4,6 @@ AM_CFLAGS = -fno-strict-aliasing
lib_LTLIBRARIES = liblttng-ust-baddr.la
liblttng_ust_baddr_la_SOURCES = \
lttng-ust-baddr.c \
- ust_baddr.c \
- ust_baddr.h \
ust_baddr_statedump.c \
ust_baddr_statedump.h
liblttng_ust_baddr_la_LIBADD = \
diff --git a/liblttng-ust-baddr/lttng-ust-baddr.c b/liblttng-ust-baddr/lttng-ust-baddr.c
index a856965..bc3c1ed 100644
--- a/liblttng-ust-baddr/lttng-ust-baddr.c
+++ b/liblttng-ust-baddr/lttng-ust-baddr.c
@@ -32,38 +32,11 @@
#include <stdio.h>
#include "usterr.h"
+#include "lttng-ust-baddr.h"
+
#define TRACEPOINT_DEFINE
-#include "ust_baddr.h"
#include "ust_baddr_statedump.h"
-int
-lttng_ust_push_baddr(void *so_base, const char *so_name)
-{
- char resolved_path[PATH_MAX];
- struct stat sostat;
-
- if (!realpath(so_name, resolved_path)) {
- ERR("could not resolve path '%s'", so_name);
- return 0;
- }
-
- if (stat(resolved_path, &sostat)) {
- ERR("could not access file status for %s", resolved_path);
- return 0;
- }
-
- tracepoint(ust_baddr, push,
- so_base, resolved_path, sostat.st_size, sostat.st_mtime);
- return 0;
-}
-
-int
-lttng_ust_pop_baddr(void *so_base)
-{
- tracepoint(ust_baddr, pop, so_base);
- return 0;
-}
-
static int
extract_soinfo_events(struct dl_phdr_info *info, size_t size, void *data)
{
@@ -129,8 +102,18 @@ lttng_ust_baddr_statedump(struct lttng_session *session)
{
/*
* Iterate through the list of currently loaded shared objects and
- * generate events for loadable segments using extract_soinfo_events
+ * generate events for loadable segments using extract_soinfo_events.
+ *
+ * The use of dlopen is required to make sure tracepoint registration
+ * happens before using the tracepoint in extract_soinfo_events().
*/
- dl_iterate_phdr(extract_soinfo_events, session);
+ void *dlref = dlopen("liblttng-ust-baddr.so.0", RTLD_NOW | RTLD_GLOBAL);
+ if (dlref) {
+ dl_iterate_phdr(extract_soinfo_events, session);
+ dlclose(dlref);
+ } else {
+ fprintf(stderr, "%s\n", dlerror());
+ return -1;
+ }
return 0;
}
diff --git a/liblttng-ust-baddr/lttng-ust-baddr.h b/liblttng-ust-baddr/lttng-ust-baddr.h
new file mode 100644
index 0000000..2229150
--- /dev/null
+++ b/liblttng-ust-baddr/lttng-ust-baddr.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2013 Paul Woegerer <paul_woegerer at mentor.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <lttng/ust-events.h>
+
+int __attribute__((weak))
+lttng_ust_baddr_statedump(struct lttng_session *session);
diff --git a/liblttng-ust-dl/Makefile.am b/liblttng-ust-dl/Makefile.am
index c408fdd..352f145 100644
--- a/liblttng-ust-dl/Makefile.am
+++ b/liblttng-ust-dl/Makefile.am
@@ -2,7 +2,10 @@ AM_CPPFLAGS = -I$(top_srcdir)/include
AM_CFLAGS = -fno-strict-aliasing
lib_LTLIBRARIES = liblttng-ust-dl.la
-liblttng_ust_dl_la_SOURCES = ustdl.c
+liblttng_ust_dl_la_SOURCES = \
+ ustdl.c \
+ ust_baddr.c \
+ ust_baddr.h
liblttng_ust_dl_la_LIBADD = \
$(top_builddir)/liblttng-ust/liblttng-ust.la
diff --git a/liblttng-ust-baddr/ust_baddr.c b/liblttng-ust-dl/ust_baddr.c
similarity index 100%
rename from liblttng-ust-baddr/ust_baddr.c
rename to liblttng-ust-dl/ust_baddr.c
diff --git a/liblttng-ust-baddr/ust_baddr.h b/liblttng-ust-dl/ust_baddr.h
similarity index 100%
rename from liblttng-ust-baddr/ust_baddr.h
rename to liblttng-ust-dl/ust_baddr.h
diff --git a/liblttng-ust-dl/ustdl.c b/liblttng-ust-dl/ustdl.c
index 8baf9ee..dbde8b7 100644
--- a/liblttng-ust-dl/ustdl.c
+++ b/liblttng-ust-dl/ustdl.c
@@ -22,6 +22,9 @@
#include <link.h>
#include <unistd.h>
#include <stdio.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
#include <signal.h>
#include <sched.h>
#include <stdarg.h>
@@ -30,9 +33,11 @@
#include <lttng/ust-compiler.h>
#include <lttng/ust.h>
+#define TRACEPOINT_DEFINE
+#include "ust_baddr.h"
+
static void *(*__lttng_ust_plibc_dlopen)(const char *filename, int flag);
static int (*__lttng_ust_plibc_dlclose)(void *handle);
-static void *__lttng_ust_baddr_handle;
static
void *_lttng_ust_dl_libc_dlopen(const char *filename, int flag)
@@ -61,53 +66,24 @@ int _lttng_ust_dl_libc_dlclose(void *handle)
}
static
-void *lttng_ust_baddr_handle(void)
+void lttng_ust_baddr_push(void *so_base, const char *so_name)
{
- if (!__lttng_ust_baddr_handle) {
- __lttng_ust_baddr_handle = _lttng_ust_dl_libc_dlopen(
- "liblttng-ust-baddr.so.0", RTLD_NOW | RTLD_GLOBAL);
- if (__lttng_ust_baddr_handle == NULL)
- fprintf(stderr, "%s\n", dlerror());
- }
- return __lttng_ust_baddr_handle;
-}
+ char resolved_path[PATH_MAX];
+ struct stat sostat;
-static
-int lttng_ust_baddr_push(void *so_base, const char *so_name)
-{
- static int
- (*lttng_ust_baddr_push_fn)(void *so_base, const char *so_name);
- if (!lttng_ust_baddr_push_fn) {
- void *baddr_handle = lttng_ust_baddr_handle();
- if (baddr_handle) {
- lttng_ust_baddr_push_fn = dlsym(baddr_handle,
- "lttng_ust_push_baddr");
- if (lttng_ust_baddr_push_fn == NULL)
- fprintf(stderr, "%s\n", dlerror());
- }
- if (!lttng_ust_baddr_push_fn)
- return -1;
+ if (!realpath(so_name, resolved_path)) {
+ ERR("could not resolve path '%s'", so_name);
+ return;
}
- return lttng_ust_baddr_push_fn(so_base, so_name);
-}
-static
-int lttng_ust_baddr_pop(void *so_base)
-{
- static int
- (*lttng_ust_baddr_pop_fn)(void *so_base);
- if (!lttng_ust_baddr_pop_fn) {
- void *baddr_handle = lttng_ust_baddr_handle();
- if (baddr_handle) {
- lttng_ust_baddr_pop_fn = dlsym(baddr_handle,
- "lttng_ust_pop_baddr");
- if (lttng_ust_baddr_pop_fn == NULL)
- fprintf(stderr, "%s\n", dlerror());
- }
- if (!lttng_ust_baddr_pop_fn)
- return -1;
+ if (stat(resolved_path, &sostat)) {
+ ERR("could not access file status for %s", resolved_path);
+ return;
}
- return lttng_ust_baddr_pop_fn(so_base);
+
+ tracepoint(ust_baddr, push,
+ so_base, resolved_path, sostat.st_size, sostat.st_mtime);
+ return;
}
void *dlopen(const char *filename, int flag)
@@ -128,19 +104,7 @@ int dlclose(void *handle)
struct link_map *p = NULL;
if (dlinfo(handle, RTLD_DI_LINKMAP, &p) != -1 && p != NULL
&& p->l_addr != 0)
- lttng_ust_baddr_pop((void *) p->l_addr);
+ tracepoint(ust_baddr, pop, (void *) p->l_addr);
}
return _lttng_ust_dl_libc_dlclose(handle);
}
-
-static void __attribute__((destructor))
-lttng_ust_baddr_handle_fini(void);
-static void
-lttng_ust_baddr_handle_fini(void)
-{
- if (__lttng_ust_baddr_handle) {
- int ret = _lttng_ust_dl_libc_dlclose(__lttng_ust_baddr_handle);
- if (ret)
- fprintf(stderr, "%s\n", dlerror());
- }
-}
diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index 77d8e3f..912521b 100644
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -52,6 +52,7 @@
#include "lttng-tracer-core.h"
#include "compat.h"
#include "../libringbuffer/tlsfixup.h"
+#include "../liblttng-ust-baddr/lttng-ust-baddr.h"
/*
* Has lttng ust comm constructor been called ?
@@ -183,7 +184,6 @@ static const char *cmd_name_mapping[] = {
static const char *str_timeout;
static int got_timeout_env;
-static void *ust_baddr_handle;
extern void lttng_ring_buffer_client_overwrite_init(void);
extern void lttng_ring_buffer_client_overwrite_rt_init(void);
@@ -243,39 +243,6 @@ void print_cmd(int cmd, int handle)
}
static
-void *lttng_ust_baddr_handle(void)
-{
- if (!ust_baddr_handle) {
- ust_baddr_handle = dlopen(
- "liblttng-ust-baddr.so.0", RTLD_NOW | RTLD_GLOBAL);
- if (ust_baddr_handle == NULL)
- ERR("%s", dlerror());
- }
- return ust_baddr_handle;
-}
-
-static
-int lttng_ust_baddr_statedump(struct lttng_session *session)
-{
- static
- int (*lttng_ust_baddr_init_fn)(struct lttng_session *);
-
- if (!lttng_ust_baddr_init_fn) {
- void *baddr_handle = lttng_ust_baddr_handle();
- if (baddr_handle) {
- lttng_ust_baddr_init_fn = dlsym(baddr_handle,
- "lttng_ust_baddr_statedump");
- if (lttng_ust_baddr_init_fn == NULL)
- ERR("%s", dlerror());
- }
- if (!lttng_ust_baddr_init_fn)
- return -1;
- }
-
- return lttng_ust_baddr_init_fn(session);
-}
-
-static
int setup_local_apps(void)
{
const char *home_dir;
@@ -1249,7 +1216,7 @@ restart:
} else {
struct lttng_session *session =
sock_info->session_enabled;
- if (session) {
+ if (session && lttng_ust_baddr_statedump) {
sock_info->session_enabled = NULL;
lttng_ust_baddr_statedump(session);
}
@@ -1489,12 +1456,6 @@ void __attribute__((destructor)) lttng_ust_exit(void)
* cleanup the threads if there are stalled in a syscall.
*/
lttng_ust_cleanup(1);
-
- if (ust_baddr_handle) {
- int ret = dlclose(ust_baddr_handle);
- if (ret)
- ERR("%s", dlerror());
- }
}
/*
--
1.8.4
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