Implement base-address-state tracing
authorPaul Woegerer <paul_woegerer@mentor.com>
Thu, 14 Nov 2013 18:39:49 +0000 (19:39 +0100)
committerMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Thu, 14 Nov 2013 19:24:32 +0000 (14:24 -0500)
Dump the base-address state (executable and shared objects) into session
on session-enable (per-session events).

Signed-off-by: Paul Woegerer <paul_woegerer@mentor.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
include/lttng/ust-tracepoint-event.h
liblttng-ust-baddr/Makefile.am
liblttng-ust-baddr/lttng-ust-baddr.c
liblttng-ust-baddr/ust_baddr_statedump.c [new file with mode: 0644]
liblttng-ust-baddr/ust_baddr_statedump.h [new file with mode: 0644]
liblttng-ust/lttng-events.c
liblttng-ust/lttng-tracer-core.h
liblttng-ust/lttng-ust-comm.c

index bb3a05d5fa8b7103f893282bc7634f7b90dc0ef1..be580307a5b3eda641fbab9414cb614ef9e5b791 100644 (file)
@@ -479,6 +479,18 @@ size_t __event_get_align__##_provider##___##_name(_TP_ARGS_PROTO(_args))      \
 #undef TP_FIELDS
 #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.
@@ -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)))                  \
index afa9489fba8b3fc6869bcba3c2558d2129301988..0d3cf28911d68c0eb8302729e2b4fdf298bf2a57 100644 (file)
@@ -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
index f24a1717277ab99c2c81f1aa6b47bc290fb9c5fd..a8569656bce804de5ea1369012ba42b3a4b0d19d 100644 (file)
@@ -34,6 +34,7 @@
 
 #define TRACEPOINT_DEFINE
 #include "ust_baddr.h"
+#include "ust_baddr_statedump.h"
 
 int
 lttng_ust_push_baddr(void *so_base, const char *so_name)
@@ -62,3 +63,74 @@ 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)
+{
+       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 interested in the base address (lowest virtual
+                * address associated with the memory image), skip the rest
+                */
+               break;
+       }
+       return 0;
+}
+
+int
+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
+        */
+       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 (file)
index 0000000..75f74ca
--- /dev/null
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2013  Paul Woegerer <paul_woegerer@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 (file)
index 0000000..77a9af4
--- /dev/null
@@ -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@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
index 61021f3a696334558654b0990b91415c6aec1670..77515843d3a0f5e2a6f895685064689aece4fd98 100644 (file)
@@ -293,6 +293,8 @@ 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->owner, session);
 end:
        return ret;
 }
index f643a7e5023f85fcb8091b56930d7cfaa8d0f95a..e7f549e0cede664c7038f92b7bc5b29a50951d51 100644 (file)
@@ -45,4 +45,7 @@ const char *lttng_ust_obj_get_name(int id);
 
 int lttng_get_notify_socket(void *owner);
 
+void lttng_ust_sockinfo_session_enabled(void *owner,
+               struct lttng_session *session_enabled);
+
 #endif /* _LTTNG_TRACER_CORE_H */
index 597712bc1313057daaa4ee32730b46c3951eb78d..77d8e3fcb3564de19100b0a50c080ecba5ba2ad4 100644 (file)
@@ -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 */
@@ -135,6 +139,8 @@ struct sock_info local_apps = {
 
        .socket = -1,
        .notify_socket = -1,
+
+       .session_enabled = NULL,
 };
 
 static int wait_poll_fallback;
@@ -177,6 +183,7 @@ 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 +242,39 @@ void print_cmd(int cmd, int handle)
                lttng_ust_obj_get_name(handle), 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)
 {
@@ -1206,6 +1246,13 @@ 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 =
+                                       sock_info->session_enabled;
+                               if (session) {
+                                       sock_info->session_enabled = NULL;
+                                       lttng_ust_baddr_statedump(session);
+                               }
                        }
                        continue;
                default:
@@ -1442,6 +1489,12 @@ 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());
+       }
 }
 
 /*
@@ -1519,3 +1572,10 @@ void ust_after_fork_child(sigset_t *restore_sigset)
        ust_after_fork_common(restore_sigset);
        lttng_ust_init();
 }
+
+void lttng_ust_sockinfo_session_enabled(void *owner,
+               struct lttng_session *session_enabled)
+{
+       struct sock_info *sock_info = owner;
+       sock_info->session_enabled = session_enabled;
+}
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