[lttng-dev] [PATCH 1/2] Base-address tracing for dlopen and dlclose

Matthew Khouzam matthew.khouzam at ericsson.com
Tue Nov 12 15:10:14 EST 2013


I am curious, why not wrap dlsym? that would allow you to get the
function names and pointers, looks like a goldmine to me.
On 13-11-11 10:28 AM, Paul Woegerer wrote:
> Provide an LD_PRELOAD library to allow tracing of calls to dlopen and
> dlclose.  Tracing the lttng-ust internal use of dlopen and dlclose is
> prevented.
>
> Signed-off-by: Paul Woegerer <paul_woegerer at mentor.com>
> ---
>  Makefile.am                          |   2 +
>  configure.ac                         |   2 +
>  include/Makefile.am                  |   1 +
>  include/lttng/tracepoint.h           |  12 +--
>  include/lttng/ust-dl.h               |  54 +++++++++++++
>  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              | 144 +++++++++++++++++++++++++++++++++++
>  11 files changed, 395 insertions(+), 5 deletions(-)
>  create mode 100644 include/lttng/ust-dl.h
>  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 dc88c46..6a82e4d 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 cc28205..bac6030 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -282,6 +282,8 @@ 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-libc-wrapper/Makefile
>  	liblttng-ust-cyg-profile/Makefile
> diff --git a/include/Makefile.am b/include/Makefile.am
> index 4f028db..b3243bf 100644
> --- a/include/Makefile.am
> +++ b/include/Makefile.am
> @@ -13,6 +13,7 @@ nobase_include_HEADERS = \
>  	lttng/ringbuffer-abi.h \
>  	lttng/ust-tracer.h \
>  	lttng/ust-compiler.h \
> +	lttng/ust-dl.h \
>  	lttng/ust.h \
>  	lttng/ust-endian.h \
>  	lttng/ringbuffer-config.h \
> diff --git a/include/lttng/tracepoint.h b/include/lttng/tracepoint.h
> index 66e2abd..c1550ec 100644
> --- a/include/lttng/tracepoint.h
> +++ b/include/lttng/tracepoint.h
> @@ -28,10 +28,10 @@
>  #include <lttng/tracepoint-types.h>
>  #include <lttng/tracepoint-rcu.h>
>  #include <urcu/compiler.h>
> -#include <dlfcn.h>	/* for dlopen */
>  #include <string.h>	/* for memset */
>  #include <lttng/ust-config.h>	/* for sdt */
>  #include <lttng/ust-compiler.h>
> +#include <lttng/ust-dl.h>	/* for lttng_ust_dlopen */
>  
>  #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
>  #define SDT_USE_VARIADIC
> @@ -278,7 +278,8 @@ __tracepoints__init(void)
>  
>  	if (!tracepoint_dlopen.liblttngust_handle)
>  		tracepoint_dlopen.liblttngust_handle =
> -			dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
> +			lttng_ust_dlopen("liblttng-ust-tracepoint.so.0",
> +				RTLD_NOW | RTLD_GLOBAL);
>  	if (!tracepoint_dlopen.liblttngust_handle)
>  		return;
>  	__tracepoint__init_urcu_sym();
> @@ -294,7 +295,7 @@ __tracepoints__destroy(void)
>  	if (--__tracepoint_registered)
>  		return;
>  	if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_ptrs_registered) {
> -		ret = dlclose(tracepoint_dlopen.liblttngust_handle);
> +		ret = lttng_ust_dlclose(tracepoint_dlopen.liblttngust_handle);
>  		if (ret) {
>  			fprintf(stderr, "Error (%d) in dlclose\n", ret);
>  			abort();
> @@ -367,7 +368,8 @@ __tracepoints__ptrs_init(void)
>  		return;
>  	if (!tracepoint_dlopen.liblttngust_handle)
>  		tracepoint_dlopen.liblttngust_handle =
> -			dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
> +			lttng_ust_dlopen("liblttng-ust-tracepoint.so.0",
> +				RTLD_NOW | RTLD_GLOBAL);
>  	if (!tracepoint_dlopen.liblttngust_handle)
>  		return;
>  	tracepoint_dlopen.tracepoint_register_lib =
> @@ -398,7 +400,7 @@ __tracepoints__ptrs_destroy(void)
>  	if (tracepoint_dlopen.tracepoint_unregister_lib)
>  		tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs);
>  	if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_registered) {
> -		ret = dlclose(tracepoint_dlopen.liblttngust_handle);
> +		ret = lttng_ust_dlclose(tracepoint_dlopen.liblttngust_handle);
>  		if (ret) {
>  			fprintf(stderr, "Error (%d) in dlclose\n", ret);
>  			abort();
> diff --git a/include/lttng/ust-dl.h b/include/lttng/ust-dl.h
> new file mode 100644
> index 0000000..f447ff4
> --- /dev/null
> +++ b/include/lttng/ust-dl.h
> @@ -0,0 +1,54 @@
> +#ifndef _LTTNG_UST_DL_H
> +#define _LTTNG_UST_DL_H
> +
> +/*
> + * 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 <dlfcn.h>
> +#include <lttng/ust-compiler.h>
> +
> +void *__attribute__((weak)) lttng_ust_notrace
> +_lttng_ust_dl_libc_dlopen(const char *filename, int flag);
> +int __attribute__((weak)) lttng_ust_notrace
> +_lttng_ust_dl_libc_dlclose(void *handle);
> +
> +static inline __attribute__((always_inline)) lttng_ust_notrace void *
> +lttng_ust_dlopen(const char *filename, int flag);
> +static void *
> +lttng_ust_dlopen(const char *filename, int flag)
> +{
> +	if (_lttng_ust_dl_libc_dlopen)
> +		return _lttng_ust_dl_libc_dlopen(filename, flag);
> +	return dlopen(filename, flag);
> +}
> +
> +static inline __attribute__((always_inline)) lttng_ust_notrace int
> +lttng_ust_dlclose(void *handle);
> +static int
> +lttng_ust_dlclose(void *handle)
> +{
> +	if (_lttng_ust_dl_libc_dlclose)
> +		return _lttng_ust_dl_libc_dlclose(handle);
> +	return dlclose(handle);
> +}
> +
> +#endif	/* _LTTNG_UST_DL_H */
> 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..314e272
> --- /dev/null
> +++ b/liblttng-ust-dl/ustdl.c
> @@ -0,0 +1,144 @@
> +/*
> + * 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;
> +
> +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);
> +}
> +
> +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());
> +	}
> +}




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