[lttng-dev] [PATCH v2] Base-address tracing for dlopen and dlclose

Paul Woegerer paul_woegerer at mentor.com
Wed Nov 13 12:14:01 EST 2013


Provide an LD_PRELOAD library to allow tracing of calls to dlopen and
dlclose.

Signed-off-by: Paul Woegerer <paul_woegerer at mentor.com>
---
 Makefile.am                          |   2 +
 configure.ac                         |   2 +
 liblttng-ust-baddr/Makefile.am       |  18 +++++
 liblttng-ust-baddr/lttng-ust-baddr.c |  64 +++++++++++++++
 liblttng-ust-baddr/ust_baddr.c       |  20 +++++
 liblttng-ust-baddr/ust_baddr.h       |  66 ++++++++++++++++
 liblttng-ust-dl/Makefile.am          |  17 ++++
 liblttng-ust-dl/ustdl.c              | 146 +++++++++++++++++++++++++++++++++++
 8 files changed, 335 insertions(+)
 create mode 100644 liblttng-ust-baddr/Makefile.am
 create mode 100644 liblttng-ust-baddr/lttng-ust-baddr.c
 create mode 100644 liblttng-ust-baddr/ust_baddr.c
 create mode 100644 liblttng-ust-baddr/ust_baddr.h
 create mode 100644 liblttng-ust-dl/Makefile.am
 create mode 100644 liblttng-ust-dl/ustdl.c

diff --git a/Makefile.am b/Makefile.am
index edb1a85..00dd576 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -4,6 +4,8 @@ SUBDIRS = . include snprintf libringbuffer liblttng-ust-comm \
 		liblttng-ust \
 		liblttng-ust-ctl \
 		liblttng-ust-fork \
+		liblttng-ust-baddr \
+		liblttng-ust-dl \
 		liblttng-ust-libc-wrapper \
 		liblttng-ust-cyg-profile \
 		tools \
diff --git a/configure.ac b/configure.ac
index c5802ee..37ea8c6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -285,6 +285,8 @@ AC_CONFIG_FILES([
 	liblttng-ust/Makefile
 	liblttng-ust-ctl/Makefile
 	liblttng-ust-fork/Makefile
+	liblttng-ust-baddr/Makefile
+	liblttng-ust-dl/Makefile
 	liblttng-ust-java/Makefile
 	liblttng-ust-jul/Makefile
 	liblttng-ust-libc-wrapper/Makefile
diff --git a/liblttng-ust-baddr/Makefile.am b/liblttng-ust-baddr/Makefile.am
new file mode 100644
index 0000000..afa9489
--- /dev/null
+++ b/liblttng-ust-baddr/Makefile.am
@@ -0,0 +1,18 @@
+AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_builddir)/include
+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
+liblttng_ust_baddr_la_LIBADD = \
+	-L$(top_builddir)/liblttng-ust/.libs \
+	-llttng-ust
+
+if LTTNG_UST_BUILD_WITH_LIBDL
+liblttng_ust_baddr_la_LIBADD += -ldl
+endif
+if LTTNG_UST_BUILD_WITH_LIBC_DL
+liblttng_ust_baddr_la_LIBADD += -lc
+endif
diff --git a/liblttng-ust-baddr/lttng-ust-baddr.c b/liblttng-ust-baddr/lttng-ust-baddr.c
new file mode 100644
index 0000000..21c22a2
--- /dev/null
+++ b/liblttng-ust-baddr/lttng-ust-baddr.c
@@ -0,0 +1,64 @@
+/*
+ * 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
+ */
+
+#define _GNU_SOURCE
+#include <dlfcn.h>
+#include <link.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdio.h>
+#include "usterr.h"
+
+#define TRACEPOINT_DEFINE
+#include "ust_baddr.h"
+
+int
+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
+pop_baddr(void *so_base)
+{
+	tracepoint(ust_baddr, pop, so_base);
+	return 0;
+}
diff --git a/liblttng-ust-baddr/ust_baddr.c b/liblttng-ust-baddr/ust_baddr.c
new file mode 100644
index 0000000..bfbb7bf
--- /dev/null
+++ b/liblttng-ust-baddr/ust_baddr.c
@@ -0,0 +1,20 @@
+/*
+ * 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
+ */
+
+#define TRACEPOINT_CREATE_PROBES
+#include "ust_baddr.h"
diff --git a/liblttng-ust-baddr/ust_baddr.h b/liblttng-ust-baddr/ust_baddr.h
new file mode 100644
index 0000000..2c757f7
--- /dev/null
+++ b/liblttng-ust-baddr/ust_baddr.h
@@ -0,0 +1,66 @@
+#undef TRACEPOINT_PROVIDER
+#define TRACEPOINT_PROVIDER ust_baddr
+
+#if !defined(_TRACEPOINT_UST_BADDR_H) || defined(TRACEPOINT_HEADER_MULTI_READ)
+#define _TRACEPOINT_UST_BADDR_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Copyright (C) 2013  Paul Woegerer <paul_woegerer at mentor.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <stdint.h>
+#include <unistd.h>
+
+#define LTTNG_UST_BADDR_PROVIDER
+#include <lttng/tracepoint.h>
+
+TRACEPOINT_EVENT(ust_baddr, push,
+	TP_ARGS(void *, baddr, const char*, sopath, int64_t, size, int64_t, mtime),
+	TP_FIELDS(
+		ctf_integer_hex(void *, baddr, baddr)
+		ctf_string(sopath, sopath)
+		ctf_integer(int64_t, size, size)
+		ctf_integer(int64_t, mtime, mtime)
+	)
+)
+
+TRACEPOINT_EVENT(ust_baddr, pop,
+	TP_ARGS(void *, baddr),
+	TP_FIELDS(
+		ctf_integer_hex(void *, baddr, baddr)
+	)
+)
+
+#endif /* _TRACEPOINT_UST_BADDR_H */
+
+#undef TRACEPOINT_INCLUDE
+#define TRACEPOINT_INCLUDE "./ust_baddr.h"
+
+/* This part must be outside ifdef protection */
+#include <lttng/tracepoint-event.h>
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/liblttng-ust-dl/Makefile.am b/liblttng-ust-dl/Makefile.am
new file mode 100644
index 0000000..14d8abf
--- /dev/null
+++ b/liblttng-ust-dl/Makefile.am
@@ -0,0 +1,17 @@
+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_LIBADD = \
+	$(top_builddir)/liblttng-ust/liblttng-ust.la
+
+if LTTNG_UST_BUILD_WITH_LIBDL
+liblttng_ust_dl_la_LIBADD += -ldl
+endif
+if LTTNG_UST_BUILD_WITH_LIBC_DL
+liblttng_ust_dl_la_LIBADD += -lc
+endif
+
+libustdl_CFLAGS = -DUST_COMPONENT=liblttng-ust-dl -fno-strict-aliasing
+
diff --git a/liblttng-ust-dl/ustdl.c b/liblttng-ust-dl/ustdl.c
new file mode 100644
index 0000000..8f22b91
--- /dev/null
+++ b/liblttng-ust-dl/ustdl.c
@@ -0,0 +1,146 @@
+/*
+ * 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; version 2.1 of
+ * the License.
+ *
+ * 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
+ */
+
+#define _GNU_SOURCE
+#include <inttypes.h>
+#include <dlfcn.h>
+#include <link.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <signal.h>
+#include <sched.h>
+#include <stdarg.h>
+#include "usterr.h"
+
+#include <lttng/ust-compiler.h>
+#include <lttng/ust.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)
+{
+	if (!__lttng_ust_plibc_dlopen) {
+		__lttng_ust_plibc_dlopen = dlsym(RTLD_NEXT, "dlopen");
+		if (__lttng_ust_plibc_dlopen == NULL) {
+			fprintf(stderr, "%s\n", dlerror());
+			return NULL;
+		}
+	}
+	return __lttng_ust_plibc_dlopen(filename, flag);
+}
+
+static
+int _lttng_ust_dl_libc_dlclose(void *handle)
+{
+	if (!__lttng_ust_plibc_dlclose) {
+		__lttng_ust_plibc_dlclose = dlsym(RTLD_NEXT, "dlclose");
+		if (__lttng_ust_plibc_dlclose == NULL) {
+			fprintf(stderr, "%s\n", dlerror());
+			return -1;
+		}
+	}
+	return __lttng_ust_plibc_dlclose(handle);
+}
+
+static
+void *lttng_ust_baddr_handle(void)
+{
+	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;
+}
+
+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,
+				"push_baddr");
+			if (lttng_ust_baddr_push_fn == NULL)
+				fprintf(stderr, "%s\n", dlerror());
+		}
+		if (!lttng_ust_baddr_push_fn)
+			return -1;
+	}
+	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,
+				"pop_baddr");
+			if (lttng_ust_baddr_pop_fn == NULL)
+				fprintf(stderr, "%s\n", dlerror());
+		}
+		if (!lttng_ust_baddr_pop_fn)
+			return -1;
+	}
+	return lttng_ust_baddr_pop_fn(so_base);
+}
+
+void *dlopen(const char *filename, int flag)
+{
+	void *handle = _lttng_ust_dl_libc_dlopen(filename, flag);
+	if (handle) {
+		struct link_map *p = NULL;
+		if (dlinfo(handle, RTLD_DI_LINKMAP, &p) != -1 && p != NULL
+				&& p->l_addr != 0)
+			lttng_ust_baddr_push((void *) p->l_addr, p->l_name);
+	}
+	return handle;
+}
+
+int dlclose(void *handle)
+{
+	if (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);
+	}
+	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());
+	}
+}
-- 
1.8.4.2




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