[lttng-dev] [PATCH v2 2/2] Implement base-address-state tracing
Paul Woegerer
paul_woegerer at mentor.com
Wed Nov 13 13:37:40 EST 2013
Dump the base-address state (executable and shared objects) into session
on session-enable (per-session events).
Signed-off-by: Paul Woegerer <paul_woegerer at mentor.com>
---
include/lttng/ust-tracepoint-event.h | 14 +++++++
liblttng-ust-baddr/Makefile.am | 4 +-
liblttng-ust-baddr/lttng-ust-baddr.c | 64 ++++++++++++++++++++++++++++++++
liblttng-ust-baddr/ust_baddr_statedump.c | 21 +++++++++++
liblttng-ust-baddr/ust_baddr_statedump.h | 60 ++++++++++++++++++++++++++++++
liblttng-ust/lttng-events.c | 4 ++
liblttng-ust/lttng-ust-comm.c | 62 +++++++++++++++++++++++++++++++
7 files changed, 228 insertions(+), 1 deletion(-)
create mode 100644 liblttng-ust-baddr/ust_baddr_statedump.c
create mode 100644 liblttng-ust-baddr/ust_baddr_statedump.h
diff --git a/include/lttng/ust-tracepoint-event.h b/include/lttng/ust-tracepoint-event.h
index bb3a05d..be58030 100644
--- a/include/lttng/ust-tracepoint-event.h
+++ b/include/lttng/ust-tracepoint-event.h
@@ -480,6 +480,18 @@ size_t __event_get_align__##_provider##___##_name(_TP_ARGS_PROTO(_args)) \
#define TP_FIELDS(...) __VA_ARGS__
/*
+ * For state dump, check that "session" argument (mandatory) matches the
+ * session this event belongs to. Ensures that we write state dump data only
+ * into the started session, not into all sessions.
+ */
+#undef _TP_SESSION_CHECK
+#ifdef TP_SESSION_CHECK
+#define _TP_SESSION_CHECK(session, csession) (session == csession)
+#else /* TP_SESSION_CHECK */
+#define _TP_SESSION_CHECK(session, csession) 1
+#endif /* TP_SESSION_CHECK */
+
+/*
* Using twice size for filter stack data to hold size and pointer for
* each field (worse case). For integers, max size required is 64-bit.
* Same for double-precision floats. Those fit within
@@ -506,6 +518,8 @@ void __event_probe__##_provider##___##_name(_TP_ARGS_DATA_PROTO(_args)) \
\
if (0) \
(void) __dynamic_len_idx; /* don't warn if unused */ \
+ if (!_TP_SESSION_CHECK(session, __chan->session)) \
+ return; \
if (caa_unlikely(!CMM_ACCESS_ONCE(__chan->session->active))) \
return; \
if (caa_unlikely(!CMM_ACCESS_ONCE(__chan->enabled))) \
diff --git a/liblttng-ust-baddr/Makefile.am b/liblttng-ust-baddr/Makefile.am
index afa9489..0d3cf28 100644
--- a/liblttng-ust-baddr/Makefile.am
+++ b/liblttng-ust-baddr/Makefile.am
@@ -5,7 +5,9 @@ lib_LTLIBRARIES = liblttng-ust-baddr.la
liblttng_ust_baddr_la_SOURCES = \
lttng-ust-baddr.c \
ust_baddr.c \
- ust_baddr.h
+ ust_baddr.h \
+ ust_baddr_statedump.c \
+ ust_baddr_statedump.h
liblttng_ust_baddr_la_LIBADD = \
-L$(top_builddir)/liblttng-ust/.libs \
-llttng-ust
diff --git a/liblttng-ust-baddr/lttng-ust-baddr.c b/liblttng-ust-baddr/lttng-ust-baddr.c
index 21c22a2..f73bf0d 100644
--- a/liblttng-ust-baddr/lttng-ust-baddr.c
+++ b/liblttng-ust-baddr/lttng-ust-baddr.c
@@ -34,6 +34,7 @@
#define TRACEPOINT_DEFINE
#include "ust_baddr.h"
+#include "ust_baddr_statedump.h"
int
push_baddr(void *so_base, const char *so_name)
@@ -62,3 +63,66 @@ 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)
+{
+ int j;
+ int num_loadable_segment = 0;
+
+ for (j = 0; j < info->dlpi_phnum; j++) {
+ char resolved_path[PATH_MAX];
+ struct stat sostat;
+ void *base_addr_ptr;
+
+ if (info->dlpi_phdr[j].p_type != PT_LOAD)
+ continue;
+
+ /* Calculate virtual memory address of the loadable segment */
+ base_addr_ptr = (void *) info->dlpi_addr
+ + info->dlpi_phdr[j].p_vaddr;
+
+ num_loadable_segment += 1;
+ if ((info->dlpi_name == NULL || info->dlpi_name[0] == 0)
+ && num_loadable_segment == 1) {
+ /* If the iterated element is the executable itself we
+ * have to use Dl_info to determine its full path */
+ Dl_info dl_info = { 0 };
+ if (!dladdr(base_addr_ptr, &dl_info))
+ return 0;
+ if (!realpath(dl_info.dli_fname, resolved_path))
+ return 0;
+ } else {
+ /* For regular dl_phdr_info entries we have to check if
+ * the path to the shared object really exists */
+ if (!realpath(info->dlpi_name, resolved_path)) {
+ /* Found vDSO, put the 'path' into brackets */
+ snprintf(resolved_path, PATH_MAX - 1, "[%s]",
+ info->dlpi_name);
+ }
+ }
+
+ if (stat(resolved_path, &sostat)) {
+ sostat.st_size = 0;
+ sostat.st_mtime = -1;
+ }
+
+ tracepoint(ust_baddr_statedump, soinfo,
+ (struct lttng_session *) data, base_addr_ptr,
+ resolved_path, sostat.st_size, sostat.st_mtime);
+
+ /* We are only interrested in the base address (lowest virtual
+ * address associated with the memory image), skip the rest */
+ break;
+ }
+ return 0;
+}
+
+int
+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 */
+ dl_iterate_phdr(extract_soinfo_events, session);
+ return 0;
+}
diff --git a/liblttng-ust-baddr/ust_baddr_statedump.c b/liblttng-ust-baddr/ust_baddr_statedump.c
new file mode 100644
index 0000000..75f74ca
--- /dev/null
+++ b/liblttng-ust-baddr/ust_baddr_statedump.c
@@ -0,0 +1,21 @@
+/*
+ * 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
+#define TP_SESSION_CHECK
+#include "ust_baddr_statedump.h"
diff --git a/liblttng-ust-baddr/ust_baddr_statedump.h b/liblttng-ust-baddr/ust_baddr_statedump.h
new file mode 100644
index 0000000..77a9af4
--- /dev/null
+++ b/liblttng-ust-baddr/ust_baddr_statedump.h
@@ -0,0 +1,60 @@
+#undef TRACEPOINT_PROVIDER
+#define TRACEPOINT_PROVIDER ust_baddr_statedump
+
+#if !defined(_TRACEPOINT_UST_BADDR_STATEDUMP_H) || defined(TRACEPOINT_HEADER_MULTI_READ)
+#define _TRACEPOINT_UST_BADDR_STATEDUMP_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>
+#include <lttng/ust-events.h>
+
+#define LTTNG_UST_BADDR_STATEDUMP_PROVIDER
+#include <lttng/tracepoint.h>
+
+TRACEPOINT_EVENT(ust_baddr_statedump, soinfo,
+ TP_ARGS(struct lttng_session *, session, 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)
+ )
+)
+
+#endif /* _TRACEPOINT_UST_BADDR_STATEDUMP_H */
+
+#undef TRACEPOINT_INCLUDE
+#define TRACEPOINT_INCLUDE "./ust_baddr_statedump.h"
+
+/* This part must be outside ifdef protection */
+#include <lttng/tracepoint-event.h>
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/liblttng-ust/lttng-events.c b/liblttng-ust/lttng-events.c
index 26601a6..65ae320 100644
--- a/liblttng-ust/lttng-events.c
+++ b/liblttng-ust/lttng-events.c
@@ -86,6 +86,8 @@ void lttng_session_sync_enablers(struct lttng_session *session);
static
void lttng_enabler_destroy(struct lttng_enabler *enabler);
+void _lttng_ust_sockinfo_session_enabled(struct lttng_session *session_enabled);
+
/*
* Called with ust lock held.
*/
@@ -293,6 +295,8 @@ int lttng_session_enable(struct lttng_session *session)
/* Set atomically the state to "active" */
CMM_ACCESS_ONCE(session->active) = 1;
CMM_ACCESS_ONCE(session->been_active) = 1;
+
+ _lttng_ust_sockinfo_session_enabled(session);
end:
return ret;
}
diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index a6e4ba3..3968804 100644
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -34,6 +34,7 @@
#include <time.h>
#include <assert.h>
#include <signal.h>
+#include <dlfcn.h>
#include <urcu/uatomic.h>
#include <urcu/futex.h>
#include <urcu/compiler.h>
@@ -106,6 +107,7 @@ struct sock_info {
char wait_shm_path[PATH_MAX];
char *wait_shm_mmap;
+ struct lttng_session *session_enabled;
};
/* Socket from app (connect) to session daemon (listen) for communication */
@@ -122,6 +124,8 @@ struct sock_info global_apps = {
.notify_socket = -1,
.wait_shm_path = "/" LTTNG_UST_WAIT_FILENAME,
+
+ .session_enabled = NULL,
};
/* TODO: allow global_apps_sock_path override */
@@ -176,6 +180,7 @@ 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);
@@ -235,6 +240,51 @@ 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 void __attribute__((destructor))
+lttng_ust_baddr_handle_fini(void);
+static void
+lttng_ust_baddr_handle_fini(void)
+{
+ if (ust_baddr_handle) {
+ int ret = dlclose(ust_baddr_handle);
+ if (ret)
+ ERR("%s", dlerror());
+ }
+}
+
+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,
+ "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;
@@ -1143,6 +1193,13 @@ restart:
ret = handle_message(sock_info, sock, &lum);
if (ret) {
ERR("Error handling message for %s socket", sock_info->name);
+ } else {
+ struct lttng_session *session =
+ global_apps.session_enabled;
+ if (session) {
+ global_apps.session_enabled = NULL;
+ lttng_ust_baddr_statedump(session);
+ }
}
continue;
default:
@@ -1456,3 +1513,8 @@ void ust_after_fork_child(sigset_t *restore_sigset)
ust_after_fork_common(restore_sigset);
lttng_ust_init();
}
+
+void _lttng_ust_sockinfo_session_enabled(struct lttng_session *session_enabled)
+{
+ global_apps.session_enabled = session_enabled;
+}
--
1.8.4.2
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