From mboxrd@z Thu Jan 1 00:00:00 1970 From: paul_woegerer@mentor.com (Paul Woegerer) Date: Tue, 26 Nov 2013 17:21:38 +0100 Subject: [lttng-dev] [PATCH] Make base-address-state tracing use LD_PRELOAD In-Reply-To: <1997349032.75116.1385387048686.JavaMail.zimbra@efficios.com> References: <1997349032.75116.1385387048686.JavaMail.zimbra@efficios.com> Message-ID: <1385482898-28664-1-git-send-email-paul_woegerer@mentor.com> Signed-off-by: Paul Woegerer --- 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 #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 + * + * 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 + +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 #include #include +#include +#include +#include #include #include #include @@ -30,9 +33,11 @@ #include #include +#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