2 * SPDX-License-Identifier: LGPL-2.1-only
4 * Copyright (C) 2011 EfficiOS Inc.
5 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
11 #include <sys/types.h>
12 #include <sys/socket.h>
15 #include <sys/types.h>
22 #include <semaphore.h>
27 #include <urcu/uatomic.h>
28 #include <urcu/compiler.h>
29 #include <lttng/urcu/urcu-ust.h>
31 #include <lttng/ust-utils.h>
32 #include <lttng/ust-events.h>
33 #include <lttng/ust-abi.h>
34 #include <lttng/ust-fork.h>
35 #include <lttng/ust-error.h>
36 #include <lttng/ust-ctl.h>
37 #include <lttng/ust-libc-wrapper.h>
38 #include <lttng/ust-thread.h>
39 #include <lttng/ust-tracer.h>
40 #include <lttng/ust-common.h>
41 #include <lttng/ust-cancelstate.h>
42 #include <urcu/tls-compat.h>
43 #include "lib/lttng-ust/futex.h"
44 #include "common/ustcomm.h"
45 #include "common/ust-fd.h"
46 #include "common/logging.h"
47 #include "common/macros.h"
48 #include "common/tracepoint.h"
49 #include "lttng-tracer-core.h"
50 #include "common/compat/pthread.h"
51 #include "common/procname.h"
52 #include "common/ringbuffer/rb-init.h"
53 #include "lttng-ust-statedump.h"
54 #include "common/clock.h"
55 #include "common/getenv.h"
56 #include "lib/lttng-ust/events.h"
57 #include "context-internal.h"
58 #include "common/align.h"
59 #include "common/counter-clients/clients.h"
60 #include "common/ringbuffer-clients/clients.h"
63 * Has lttng ust comm constructor been called ?
65 static int initialized
;
68 * The ust_lock/ust_unlock lock is used as a communication thread mutex.
69 * Held when handling a command, also held by fork() to deal with
70 * removal of threads, and by exit path.
72 * The UST lock is the centralized mutex across UST tracing control and
75 * ust_exit_mutex must never nest in ust_mutex.
77 * ust_fork_mutex must never nest in ust_mutex.
79 * ust_mutex_nest is a per-thread nesting counter, allowing the perf
80 * counter lazy initialization called by events within the statedump,
81 * which traces while the ust_mutex is held.
83 * ust_lock nests within the dynamic loader lock (within glibc) because
84 * it is taken within the library constructor.
86 * The ust fd tracker lock nests within the ust_mutex.
88 static pthread_mutex_t ust_mutex
= PTHREAD_MUTEX_INITIALIZER
;
90 /* Allow nesting the ust_mutex within the same thread. */
91 static DEFINE_URCU_TLS(int, ust_mutex_nest
);
94 * ust_exit_mutex protects thread_active variable wrt thread exit. It
95 * cannot be done by ust_mutex because pthread_cancel(), which takes an
96 * internal libc lock, cannot nest within ust_mutex.
98 * It never nests within a ust_mutex.
100 static pthread_mutex_t ust_exit_mutex
= PTHREAD_MUTEX_INITIALIZER
;
103 * ust_fork_mutex protects base address statedump tracing against forks. It
104 * prevents the dynamic loader lock to be taken (by base address statedump
105 * tracing) while a fork is happening, thus preventing deadlock issues with
106 * the dynamic loader lock.
108 static pthread_mutex_t ust_fork_mutex
= PTHREAD_MUTEX_INITIALIZER
;
110 /* Should the ust comm thread quit ? */
111 static int lttng_ust_comm_should_quit
;
114 * This variable can be tested by applications to check whether
115 * lttng-ust is loaded. They simply have to define their own
116 * "lttng_ust_loaded" weak symbol, and test it. It is set to 1 by the
117 * library constructor.
119 int lttng_ust_loaded
__attribute__((weak
));
122 * Notes on async-signal-safety of ust lock: a few libc functions are used
123 * which are not strictly async-signal-safe:
125 * - pthread_setcancelstate
126 * - pthread_mutex_lock
127 * - pthread_mutex_unlock
129 * As of glibc 2.35, the implementation of pthread_setcancelstate only
130 * touches TLS data, and it appears to be safe to use from signal
131 * handlers. If the libc implementation changes, this will need to be
132 * revisited, and we may ask glibc to provide an async-signal-safe
133 * pthread_setcancelstate.
135 * As of glibc 2.35, the implementation of pthread_mutex_lock/unlock
136 * for fast mutexes only relies on the pthread_mutex_t structure.
137 * Disabling signals around all uses of this mutex ensures
138 * signal-safety. If the libc implementation changes and eventually uses
139 * other global resources, this will need to be revisited and we may
140 * need to implement our own mutex.
144 * Return 0 on success, -1 if should quit.
145 * The lock is taken in both cases.
150 sigset_t sig_all_blocked
, orig_mask
;
153 if (lttng_ust_cancelstate_disable_push()) {
154 ERR("lttng_ust_cancelstate_disable_push");
156 sigfillset(&sig_all_blocked
);
157 ret
= pthread_sigmask(SIG_SETMASK
, &sig_all_blocked
, &orig_mask
);
159 ERR("pthread_sigmask: ret=%d", ret
);
161 if (!URCU_TLS(ust_mutex_nest
)++)
162 pthread_mutex_lock(&ust_mutex
);
163 ret
= pthread_sigmask(SIG_SETMASK
, &orig_mask
, NULL
);
165 ERR("pthread_sigmask: ret=%d", ret
);
167 if (lttng_ust_comm_should_quit
) {
175 * ust_lock_nocheck() can be used in constructors/destructors, because
176 * they are already nested within the dynamic loader lock, and therefore
177 * have exclusive access against execution of liblttng-ust destructor.
180 void ust_lock_nocheck(void)
182 sigset_t sig_all_blocked
, orig_mask
;
185 if (lttng_ust_cancelstate_disable_push()) {
186 ERR("lttng_ust_cancelstate_disable_push");
188 sigfillset(&sig_all_blocked
);
189 ret
= pthread_sigmask(SIG_SETMASK
, &sig_all_blocked
, &orig_mask
);
191 ERR("pthread_sigmask: ret=%d", ret
);
193 if (!URCU_TLS(ust_mutex_nest
)++)
194 pthread_mutex_lock(&ust_mutex
);
195 ret
= pthread_sigmask(SIG_SETMASK
, &orig_mask
, NULL
);
197 ERR("pthread_sigmask: ret=%d", ret
);
204 void ust_unlock(void)
206 sigset_t sig_all_blocked
, orig_mask
;
209 sigfillset(&sig_all_blocked
);
210 ret
= pthread_sigmask(SIG_SETMASK
, &sig_all_blocked
, &orig_mask
);
212 ERR("pthread_sigmask: ret=%d", ret
);
214 if (!--URCU_TLS(ust_mutex_nest
))
215 pthread_mutex_unlock(&ust_mutex
);
216 ret
= pthread_sigmask(SIG_SETMASK
, &orig_mask
, NULL
);
218 ERR("pthread_sigmask: ret=%d", ret
);
220 if (lttng_ust_cancelstate_disable_pop()) {
221 ERR("lttng_ust_cancelstate_disable_pop");
226 * Wait for either of these before continuing to the main
228 * - the register_done message from sessiond daemon
229 * (will let the sessiond daemon enable sessions before main
231 * - sessiond daemon is not reachable.
232 * - timeout (ensuring applications are resilient to session
235 static sem_t constructor_wait
;
237 * Doing this for the ust_app, global and local sessiond.
240 sem_count_initial_value
= 6,
243 static int sem_count
= sem_count_initial_value
;
246 * Counting nesting within lttng-ust. Used to ensure that calling fork()
247 * from liblttng-ust does not execute the pre/post fork handlers.
249 static DEFINE_URCU_TLS(int, lttng_ust_nest_count
);
252 * Info about socket and associated listener thread.
256 pthread_t ust_listener
; /* listener thread */
258 int registration_done
;
263 char sock_path
[PATH_MAX
];
268 * If wait_shm_is_file is true, use standard open to open and
269 * create the shared memory used for waiting on session daemon.
270 * Otherwise, use shm_open to create this file.
272 bool wait_shm_is_file
;
273 char wait_shm_path
[PATH_MAX
];
276 /* Keep track of lazy state dump not performed yet. */
277 int statedump_pending
;
278 int initial_statedump_done
;
279 /* Keep procname for statedump */
280 char procname
[LTTNG_UST_CONTEXT_PROCNAME_LEN
];
283 /* Socket from app (connect) to session daemon (listen) for communication */
284 static struct sock_info ust_app
= {
289 .registration_done
= 0,
296 .wait_shm_is_file
= true,
298 .statedump_pending
= 0,
299 .initial_statedump_done
= 0,
304 static struct sock_info global_apps
= {
309 .registration_done
= 0,
313 .sock_path
= LTTNG_DEFAULT_RUNDIR
"/" LTTNG_UST_SOCK_FILENAME
,
317 .wait_shm_is_file
= false,
318 .wait_shm_path
= "/" LTTNG_UST_WAIT_FILENAME
,
320 .statedump_pending
= 0,
321 .initial_statedump_done
= 0,
325 static struct sock_info local_apps
= {
329 .registration_done
= 0,
330 .allowed
= 0, /* Check setuid bit first */
336 .wait_shm_is_file
= false,
338 .statedump_pending
= 0,
339 .initial_statedump_done
= 0,
343 static int wait_poll_fallback
;
345 static const char *cmd_name_mapping
[] = {
346 [ LTTNG_UST_ABI_RELEASE
] = "Release",
347 [ LTTNG_UST_ABI_SESSION
] = "Create Session",
348 [ LTTNG_UST_ABI_TRACER_VERSION
] = "Get Tracer Version",
350 [ LTTNG_UST_ABI_TRACEPOINT_LIST
] = "Create Tracepoint List",
351 [ LTTNG_UST_ABI_WAIT_QUIESCENT
] = "Wait for Quiescent State",
352 [ LTTNG_UST_ABI_REGISTER_DONE
] = "Registration Done",
353 [ LTTNG_UST_ABI_TRACEPOINT_FIELD_LIST
] = "Create Tracepoint Field List",
355 [ LTTNG_UST_ABI_EVENT_NOTIFIER_GROUP_CREATE
] = "Create event notifier group",
357 /* Session FD commands */
358 [ LTTNG_UST_ABI_CHANNEL
] = "Create Channel",
359 [ LTTNG_UST_ABI_SESSION_START
] = "Start Session",
360 [ LTTNG_UST_ABI_SESSION_STOP
] = "Stop Session",
362 /* Channel FD commands */
363 [ LTTNG_UST_ABI_STREAM
] = "Create Stream",
364 [ LTTNG_UST_ABI_EVENT
] = "Create Event",
366 /* Event and Channel FD commands */
367 [ LTTNG_UST_ABI_CONTEXT
] = "Create Context",
368 [ LTTNG_UST_ABI_FLUSH_BUFFER
] = "Flush Buffer",
370 /* Event, Channel and Session commands */
371 [ LTTNG_UST_ABI_ENABLE
] = "Enable",
372 [ LTTNG_UST_ABI_DISABLE
] = "Disable",
374 /* Tracepoint list commands */
375 [ LTTNG_UST_ABI_TRACEPOINT_LIST_GET
] = "List Next Tracepoint",
376 [ LTTNG_UST_ABI_TRACEPOINT_FIELD_LIST_GET
] = "List Next Tracepoint Field",
378 /* Event FD commands */
379 [ LTTNG_UST_ABI_FILTER
] = "Create Filter",
380 [ LTTNG_UST_ABI_EXCLUSION
] = "Add exclusions to event",
382 /* Event notifier group commands */
383 [ LTTNG_UST_ABI_EVENT_NOTIFIER_CREATE
] = "Create event notifier",
385 /* Session and event notifier group commands */
386 [ LTTNG_UST_ABI_COUNTER
] = "Create Counter",
388 /* Counter commands */
389 [ LTTNG_UST_ABI_COUNTER_GLOBAL
] = "Create Counter Global",
390 [ LTTNG_UST_ABI_COUNTER_CPU
] = "Create Counter CPU",
393 static const char *str_timeout
;
394 static int got_timeout_env
;
396 static char *get_map_shm(struct sock_info
*sock_info
);
399 * Returns the HOME directory path. Caller MUST NOT free(3) the returned
403 const char *get_lttng_home_dir(void)
407 val
= (const char *) lttng_ust_getenv("LTTNG_HOME");
411 return (const char *) lttng_ust_getenv("HOME");
415 const char *get_lttng_ust_app_path(void)
417 return (const char *) lttng_ust_getenv("LTTNG_UST_APP_PATH");
421 * Force a read (imply TLS allocation for dlopen) of TLS variables.
424 void lttng_ust_nest_count_alloc_tls(void)
426 __asm__
__volatile__ ("" : : "m" (URCU_TLS(lttng_ust_nest_count
)));
430 void lttng_ust_mutex_nest_alloc_tls(void)
432 __asm__
__volatile__ ("" : : "m" (URCU_TLS(ust_mutex_nest
)));
436 * Allocate lttng-ust urcu TLS.
439 void lttng_ust_urcu_alloc_tls(void)
441 (void) lttng_ust_urcu_read_ongoing();
444 void lttng_ust_common_init_thread(int flags
)
446 lttng_ust_urcu_alloc_tls();
447 lttng_ringbuffer_alloc_tls();
448 lttng_ust_vtid_init_thread(flags
);
449 lttng_ust_nest_count_alloc_tls();
450 lttng_ust_procname_init_thread(flags
);
451 lttng_ust_mutex_nest_alloc_tls();
452 lttng_ust_perf_counter_init_thread(flags
);
453 lttng_ust_common_alloc_tls();
454 lttng_ust_cgroup_ns_init_thread(flags
);
455 lttng_ust_ipc_ns_init_thread(flags
);
456 lttng_ust_net_ns_init_thread(flags
);
457 lttng_ust_time_ns_init_thread(flags
);
458 lttng_ust_uts_ns_init_thread(flags
);
459 lttng_ust_ring_buffer_client_discard_alloc_tls();
460 lttng_ust_ring_buffer_client_discard_rt_alloc_tls();
461 lttng_ust_ring_buffer_client_overwrite_alloc_tls();
462 lttng_ust_ring_buffer_client_overwrite_rt_alloc_tls();
466 * LTTng-UST uses Global Dynamic model TLS variables rather than IE
467 * model because many versions of glibc don't preallocate a pool large
468 * enough for TLS variables IE model defined in other shared libraries,
469 * and causes issues when using LTTng-UST for Java tracing.
471 * Because of this use of Global Dynamic TLS variables, users wishing to
472 * trace from signal handlers need to explicitly trigger the lazy
473 * allocation of those variables for each thread before using them.
474 * This can be triggered by calling lttng_ust_init_thread().
476 void lttng_ust_init_thread(void)
479 * Because those TLS variables are global dynamic, we need to
480 * ensure those are initialized before a signal handler nesting over
481 * this thread attempts to use them.
483 lttng_ust_common_init_thread(LTTNG_UST_INIT_THREAD_MASK
);
485 lttng_ust_urcu_register_thread();
488 int lttng_get_notify_socket(void *owner
)
490 struct sock_info
*info
= owner
;
492 return info
->notify_socket
;
496 char* lttng_ust_sockinfo_get_procname(void *owner
)
498 struct sock_info
*info
= owner
;
500 return info
->procname
;
504 void print_cmd(int cmd
, int handle
)
506 const char *cmd_name
= "Unknown";
508 if (cmd
>= 0 && cmd
< LTTNG_ARRAY_SIZE(cmd_name_mapping
)
509 && cmd_name_mapping
[cmd
]) {
510 cmd_name
= cmd_name_mapping
[cmd
];
512 DBG("Message Received \"%s\" (%d), Handle \"%s\" (%d)",
514 lttng_ust_obj_get_name(handle
), handle
);
518 int setup_ust_apps(void)
520 const char *ust_app_path
;
524 assert(!ust_app
.wait_shm_mmap
);
528 * Disallow ust apps tracing for setuid binaries, because we
529 * cannot use the environment variables anyway.
531 if (uid
!= geteuid()) {
532 DBG("UST app tracing disabled for setuid binary.");
533 assert(ust_app
.allowed
== 0);
537 ust_app_path
= get_lttng_ust_app_path();
539 DBG("LTTNG_UST_APP_PATH environment variable not set.");
540 assert(ust_app
.allowed
== 0);
545 * The LTTNG_UST_APP_PATH env. var. disables global and local
546 * sessiond connections.
549 snprintf(ust_app
.sock_path
, PATH_MAX
, "%s/%s",
550 ust_app_path
, LTTNG_UST_SOCK_FILENAME
);
551 snprintf(ust_app
.wait_shm_path
, PATH_MAX
, "%s/%s",
553 LTTNG_UST_WAIT_FILENAME
);
555 ust_app
.wait_shm_mmap
= get_map_shm(&ust_app
);
556 if (!ust_app
.wait_shm_mmap
) {
557 WARN("Unable to get map shm for ust_app. Disabling LTTng-UST ust_app tracing.");
563 lttng_pthread_getname_np(ust_app
.procname
, LTTNG_UST_CONTEXT_PROCNAME_LEN
);
569 int setup_global_apps(void)
572 assert(!global_apps
.wait_shm_mmap
);
575 * The LTTNG_UST_APP_PATH env. var. disables global sessiond
581 global_apps
.wait_shm_mmap
= get_map_shm(&global_apps
);
582 if (!global_apps
.wait_shm_mmap
) {
583 WARN("Unable to get map shm for global apps. Disabling LTTng-UST global tracing.");
584 global_apps
.allowed
= 0;
589 global_apps
.allowed
= 1;
590 lttng_pthread_getname_np(global_apps
.procname
, LTTNG_UST_CONTEXT_PROCNAME_LEN
);
596 int setup_local_apps(void)
599 const char *home_dir
;
602 assert(!local_apps
.wait_shm_mmap
);
605 * The LTTNG_UST_APP_PATH env. var. disables local sessiond
613 * Disallow per-user tracing for setuid binaries.
615 if (uid
!= geteuid()) {
616 assert(local_apps
.allowed
== 0);
620 home_dir
= get_lttng_home_dir();
622 WARN("HOME environment variable not set. Disabling LTTng-UST per-user tracing.");
623 assert(local_apps
.allowed
== 0);
627 local_apps
.allowed
= 1;
628 snprintf(local_apps
.sock_path
, PATH_MAX
, "%s/%s/%s",
630 LTTNG_DEFAULT_HOME_RUNDIR
,
631 LTTNG_UST_SOCK_FILENAME
);
632 snprintf(local_apps
.wait_shm_path
, PATH_MAX
, "/%s-%u",
633 LTTNG_UST_WAIT_FILENAME
,
636 local_apps
.wait_shm_mmap
= get_map_shm(&local_apps
);
637 if (!local_apps
.wait_shm_mmap
) {
638 WARN("Unable to get map shm for local apps. Disabling LTTng-UST per-user tracing.");
639 local_apps
.allowed
= 0;
644 lttng_pthread_getname_np(local_apps
.procname
, LTTNG_UST_CONTEXT_PROCNAME_LEN
);
650 * Get socket timeout, in ms.
651 * -1: wait forever. 0: don't wait. >0: timeout, in ms.
654 long get_timeout(void)
656 long constructor_delay_ms
= LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS
;
658 if (!got_timeout_env
) {
659 str_timeout
= lttng_ust_getenv("LTTNG_UST_REGISTER_TIMEOUT");
663 constructor_delay_ms
= strtol(str_timeout
, NULL
, 10);
664 /* All negative values are considered as "-1". */
665 if (constructor_delay_ms
< -1)
666 constructor_delay_ms
= -1;
667 return constructor_delay_ms
;
670 /* Timeout for notify socket send and recv. */
672 long get_notify_sock_timeout(void)
674 return get_timeout();
677 /* Timeout for connecting to cmd and notify sockets. */
679 long get_connect_sock_timeout(void)
681 return get_timeout();
685 * Return values: -1: wait forever. 0: don't wait. 1: timeout wait.
688 int get_constructor_timeout(struct timespec
*constructor_timeout
)
690 long constructor_delay_ms
;
693 constructor_delay_ms
= get_timeout();
695 switch (constructor_delay_ms
) {
696 case -1:/* fall-through */
698 return constructor_delay_ms
;
704 * If we are unable to find the current time, don't wait.
706 ret
= clock_gettime(CLOCK_REALTIME
, constructor_timeout
);
711 constructor_timeout
->tv_sec
+= constructor_delay_ms
/ 1000UL;
712 constructor_timeout
->tv_nsec
+=
713 (constructor_delay_ms
% 1000UL) * 1000000UL;
714 if (constructor_timeout
->tv_nsec
>= 1000000000UL) {
715 constructor_timeout
->tv_sec
++;
716 constructor_timeout
->tv_nsec
-= 1000000000UL;
718 /* Timeout wait (constructor_delay_ms). */
723 void get_allow_blocking(void)
725 const char *str_allow_blocking
=
726 lttng_ust_getenv("LTTNG_UST_ALLOW_BLOCKING");
728 if (str_allow_blocking
) {
729 DBG("%s environment variable is set",
730 "LTTNG_UST_ALLOW_BLOCKING");
731 lttng_ust_ringbuffer_set_allow_blocking();
736 int register_to_sessiond(int socket
, enum lttng_ust_ctl_socket_type type
,
737 const char *procname
)
739 return ustcomm_send_reg_msg(socket
,
742 lttng_ust_rb_alignof(uint8_t) * CHAR_BIT
,
743 lttng_ust_rb_alignof(uint16_t) * CHAR_BIT
,
744 lttng_ust_rb_alignof(uint32_t) * CHAR_BIT
,
745 lttng_ust_rb_alignof(uint64_t) * CHAR_BIT
,
746 lttng_ust_rb_alignof(unsigned long) * CHAR_BIT
,
751 int send_reply(int sock
, struct ustcomm_ust_reply
*lur
)
755 len
= ustcomm_send_unix_sock(sock
, lur
, sizeof(*lur
));
758 DBG("message successfully sent");
761 if (len
== -ECONNRESET
) {
762 DBG("remote end closed connection");
767 DBG("incorrect message size: %zd", len
);
773 void decrement_sem_count(unsigned int count
)
777 assert(uatomic_read(&sem_count
) >= count
);
779 if (uatomic_read(&sem_count
) <= 0) {
783 ret
= uatomic_add_return(&sem_count
, -count
);
785 ret
= sem_post(&constructor_wait
);
791 int handle_register_done(struct sock_info
*sock_info
)
793 if (sock_info
->registration_done
)
795 sock_info
->registration_done
= 1;
797 decrement_sem_count(1);
798 if (!sock_info
->statedump_pending
) {
799 sock_info
->initial_statedump_done
= 1;
800 decrement_sem_count(1);
807 int handle_register_failed(struct sock_info
*sock_info
)
809 if (sock_info
->registration_done
)
811 sock_info
->registration_done
= 1;
812 sock_info
->initial_statedump_done
= 1;
814 decrement_sem_count(2);
820 * Only execute pending statedump after the constructor semaphore has
821 * been posted by the current listener thread. This means statedump will
822 * only be performed after the "registration done" command is received
823 * from this thread's session daemon.
825 * This ensures we don't run into deadlock issues with the dynamic
826 * loader mutex, which is held while the constructor is called and
827 * waiting on the constructor semaphore. All operations requiring this
828 * dynamic loader lock need to be postponed using this mechanism.
830 * In a scenario with two session daemons connected to the application,
831 * it is possible that the first listener thread which receives the
832 * registration done command issues its statedump while the dynamic
833 * loader lock is still held by the application constructor waiting on
834 * the semaphore. It will however be allowed to proceed when the
835 * second session daemon sends the registration done command to the
836 * second listener thread. This situation therefore does not produce
840 void handle_pending_statedump(struct sock_info
*sock_info
)
842 if (sock_info
->registration_done
&& sock_info
->statedump_pending
) {
843 sock_info
->statedump_pending
= 0;
844 pthread_mutex_lock(&ust_fork_mutex
);
845 lttng_handle_pending_statedump(sock_info
);
846 pthread_mutex_unlock(&ust_fork_mutex
);
848 if (!sock_info
->initial_statedump_done
) {
849 sock_info
->initial_statedump_done
= 1;
850 decrement_sem_count(1);
856 const char *bytecode_type_str(uint32_t cmd
)
859 case LTTNG_UST_ABI_CAPTURE
:
861 case LTTNG_UST_ABI_FILTER
:
869 int handle_bytecode_recv(struct sock_info
*sock_info
,
870 int sock
, struct ustcomm_ust_msg
*lum
)
872 struct lttng_ust_bytecode_node
*bytecode
= NULL
;
873 enum lttng_ust_bytecode_type type
;
874 const struct lttng_ust_abi_objd_ops
*ops
;
875 uint32_t data_size
, data_size_max
, reloc_offset
;
881 case LTTNG_UST_ABI_FILTER
:
882 type
= LTTNG_UST_BYTECODE_TYPE_FILTER
;
883 data_size
= lum
->u
.filter
.data_size
;
884 data_size_max
= LTTNG_UST_ABI_FILTER_BYTECODE_MAX_LEN
;
885 reloc_offset
= lum
->u
.filter
.reloc_offset
;
886 seqnum
= lum
->u
.filter
.seqnum
;
888 case LTTNG_UST_ABI_CAPTURE
:
889 type
= LTTNG_UST_BYTECODE_TYPE_CAPTURE
;
890 data_size
= lum
->u
.capture
.data_size
;
891 data_size_max
= LTTNG_UST_ABI_CAPTURE_BYTECODE_MAX_LEN
;
892 reloc_offset
= lum
->u
.capture
.reloc_offset
;
893 seqnum
= lum
->u
.capture
.seqnum
;
899 if (data_size
> data_size_max
) {
900 ERR("Bytecode %s data size is too large: %u bytes",
901 bytecode_type_str(lum
->cmd
), data_size
);
906 if (reloc_offset
> data_size
) {
907 ERR("Bytecode %s reloc offset %u is not within data",
908 bytecode_type_str(lum
->cmd
), reloc_offset
);
913 /* Allocate the structure AND the `data[]` field. */
914 bytecode
= zmalloc(sizeof(*bytecode
) + data_size
);
920 bytecode
->bc
.len
= data_size
;
921 bytecode
->bc
.reloc_offset
= reloc_offset
;
922 bytecode
->bc
.seqnum
= seqnum
;
923 bytecode
->type
= type
;
925 len
= ustcomm_recv_unix_sock(sock
, bytecode
->bc
.data
, bytecode
->bc
.len
);
927 case 0: /* orderly shutdown */
931 if (len
== bytecode
->bc
.len
) {
932 DBG("Bytecode %s data received",
933 bytecode_type_str(lum
->cmd
));
935 } else if (len
< 0) {
936 DBG("Receive failed from lttng-sessiond with errno %d",
938 if (len
== -ECONNRESET
) {
939 ERR("%s remote end closed connection",
947 DBG("Incorrect %s bytecode data message size: %zd",
948 bytecode_type_str(lum
->cmd
), len
);
954 ops
= lttng_ust_abi_objd_ops(lum
->handle
);
961 ret
= ops
->cmd(lum
->handle
, lum
->cmd
,
962 (unsigned long) &bytecode
,
973 void prepare_cmd_reply(struct ustcomm_ust_reply
*lur
, uint32_t handle
, uint32_t cmd
, int ret
)
975 lur
->handle
= handle
;
979 lur
->ret_code
= LTTNG_UST_OK
;
982 * Use -LTTNG_UST_ERR as wildcard for UST internal
983 * error that are not caused by the transport, except if
984 * we already have a more precise error message to
987 if (ret
> -LTTNG_UST_ERR
) {
988 /* Translate code to UST error. */
991 lur
->ret_code
= -LTTNG_UST_ERR_EXIST
;
994 lur
->ret_code
= -LTTNG_UST_ERR_INVAL
;
997 lur
->ret_code
= -LTTNG_UST_ERR_NOENT
;
1000 lur
->ret_code
= -LTTNG_UST_ERR_PERM
;
1003 lur
->ret_code
= -LTTNG_UST_ERR_NOSYS
;
1006 lur
->ret_code
= -LTTNG_UST_ERR
;
1010 lur
->ret_code
= ret
;
1016 int handle_message(struct sock_info
*sock_info
,
1017 int sock
, struct ustcomm_ust_msg
*lum
)
1020 const struct lttng_ust_abi_objd_ops
*ops
;
1021 struct ustcomm_ust_reply lur
;
1022 union lttng_ust_abi_args args
;
1023 char ctxstr
[LTTNG_UST_ABI_SYM_NAME_LEN
]; /* App context string. */
1026 memset(&lur
, 0, sizeof(lur
));
1029 ret
= -LTTNG_UST_ERR_EXITING
;
1033 ops
= lttng_ust_abi_objd_ops(lum
->handle
);
1040 case LTTNG_UST_ABI_FILTER
:
1041 case LTTNG_UST_ABI_EXCLUSION
:
1042 case LTTNG_UST_ABI_CHANNEL
:
1043 case LTTNG_UST_ABI_STREAM
:
1044 case LTTNG_UST_ABI_CONTEXT
:
1046 * Those commands send additional payload after struct
1047 * ustcomm_ust_msg, which makes it pretty much impossible to
1048 * deal with "unknown command" errors without leaving the
1049 * communication pipe in a out-of-sync state. This is part of
1050 * the ABI between liblttng-ust-ctl and liblttng-ust, and
1051 * should be fixed on the next breaking
1052 * LTTNG_UST_ABI_MAJOR_VERSION protocol bump by indicating the
1053 * total command message length as part of a message header so
1054 * that the protocol can recover from invalid command errors.
1058 case LTTNG_UST_ABI_CAPTURE
:
1059 case LTTNG_UST_ABI_COUNTER
:
1060 case LTTNG_UST_ABI_COUNTER_GLOBAL
:
1061 case LTTNG_UST_ABI_COUNTER_CPU
:
1062 case LTTNG_UST_ABI_EVENT_NOTIFIER_CREATE
:
1063 case LTTNG_UST_ABI_EVENT_NOTIFIER_GROUP_CREATE
:
1065 * Those commands expect a reply to the struct ustcomm_ust_msg
1066 * before sending additional payload.
1068 prepare_cmd_reply(&lur
, lum
->handle
, lum
->cmd
, 0);
1070 ret
= send_reply(sock
, &lur
);
1072 DBG("error sending reply");
1079 * Other commands either don't send additional payload, or are
1086 case LTTNG_UST_ABI_REGISTER_DONE
:
1087 if (lum
->handle
== LTTNG_UST_ABI_ROOT_HANDLE
)
1088 ret
= handle_register_done(sock_info
);
1092 case LTTNG_UST_ABI_RELEASE
:
1093 if (lum
->handle
== LTTNG_UST_ABI_ROOT_HANDLE
)
1096 ret
= lttng_ust_abi_objd_unref(lum
->handle
, 1);
1098 case LTTNG_UST_ABI_CAPTURE
:
1099 case LTTNG_UST_ABI_FILTER
:
1100 ret
= handle_bytecode_recv(sock_info
, sock
, lum
);
1104 case LTTNG_UST_ABI_EXCLUSION
:
1106 /* Receive exclusion names */
1107 struct lttng_ust_excluder_node
*node
;
1110 count
= lum
->u
.exclusion
.count
;
1112 /* There are no names to read */
1116 node
= zmalloc(sizeof(*node
) +
1117 count
* LTTNG_UST_ABI_SYM_NAME_LEN
);
1122 node
->excluder
.count
= count
;
1123 len
= ustcomm_recv_unix_sock(sock
, node
->excluder
.names
,
1124 count
* LTTNG_UST_ABI_SYM_NAME_LEN
);
1126 case 0: /* orderly shutdown */
1131 if (len
== count
* LTTNG_UST_ABI_SYM_NAME_LEN
) {
1132 DBG("Exclusion data received");
1134 } else if (len
< 0) {
1135 DBG("Receive failed from lttng-sessiond with errno %d", (int) -len
);
1136 if (len
== -ECONNRESET
) {
1137 ERR("%s remote end closed connection", sock_info
->name
);
1146 DBG("Incorrect exclusion data message size: %zd", len
);
1153 ret
= ops
->cmd(lum
->handle
, lum
->cmd
,
1154 (unsigned long) &node
,
1161 case LTTNG_UST_ABI_EVENT_NOTIFIER_GROUP_CREATE
:
1163 int event_notifier_notif_fd
, close_ret
;
1165 len
= ustcomm_recv_event_notifier_notif_fd_from_sessiond(sock
,
1166 &event_notifier_notif_fd
);
1168 case 0: /* orderly shutdown */
1175 DBG("Receive failed from lttng-sessiond with errno %d",
1177 if (len
== -ECONNRESET
) {
1178 ERR("%s remote end closed connection",
1186 DBG("Incorrect event notifier fd message size: %zd",
1192 args
.event_notifier_handle
.event_notifier_notif_fd
=
1193 event_notifier_notif_fd
;
1195 ret
= ops
->cmd(lum
->handle
, lum
->cmd
,
1196 (unsigned long) &lum
->u
,
1200 if (args
.event_notifier_handle
.event_notifier_notif_fd
>= 0) {
1201 lttng_ust_lock_fd_tracker();
1202 close_ret
= close(args
.event_notifier_handle
.event_notifier_notif_fd
);
1203 lttng_ust_unlock_fd_tracker();
1209 case LTTNG_UST_ABI_CHANNEL
:
1214 len
= ustcomm_recv_channel_from_sessiond(sock
,
1215 &chan_data
, lum
->u
.channel
.len
,
1218 case 0: /* orderly shutdown */
1222 if (len
== lum
->u
.channel
.len
) {
1223 DBG("channel data received");
1225 } else if (len
< 0) {
1226 DBG("Receive failed from lttng-sessiond with errno %d", (int) -len
);
1227 if (len
== -ECONNRESET
) {
1228 ERR("%s remote end closed connection", sock_info
->name
);
1235 DBG("incorrect channel data message size: %zd", len
);
1240 args
.channel
.chan_data
= chan_data
;
1241 args
.channel
.wakeup_fd
= wakeup_fd
;
1243 ret
= ops
->cmd(lum
->handle
, lum
->cmd
,
1244 (unsigned long) &lum
->u
,
1248 if (args
.channel
.wakeup_fd
>= 0) {
1251 lttng_ust_lock_fd_tracker();
1252 close_ret
= close(args
.channel
.wakeup_fd
);
1253 lttng_ust_unlock_fd_tracker();
1254 args
.channel
.wakeup_fd
= -1;
1258 free(args
.channel
.chan_data
);
1261 case LTTNG_UST_ABI_STREAM
:
1265 /* Receive shm_fd, wakeup_fd */
1266 ret
= ustcomm_recv_stream_from_sessiond(sock
,
1268 &args
.stream
.shm_fd
,
1269 &args
.stream
.wakeup_fd
);
1275 ret
= ops
->cmd(lum
->handle
, lum
->cmd
,
1276 (unsigned long) &lum
->u
,
1280 if (args
.stream
.shm_fd
>= 0) {
1281 lttng_ust_lock_fd_tracker();
1282 close_ret
= close(args
.stream
.shm_fd
);
1283 lttng_ust_unlock_fd_tracker();
1284 args
.stream
.shm_fd
= -1;
1288 if (args
.stream
.wakeup_fd
>= 0) {
1289 lttng_ust_lock_fd_tracker();
1290 close_ret
= close(args
.stream
.wakeup_fd
);
1291 lttng_ust_unlock_fd_tracker();
1292 args
.stream
.wakeup_fd
= -1;
1298 case LTTNG_UST_ABI_CONTEXT
:
1299 switch (lum
->u
.context
.ctx
) {
1300 case LTTNG_UST_ABI_CONTEXT_APP_CONTEXT
:
1303 size_t ctxlen
, recvlen
;
1305 ctxlen
= strlen("$app.") + lum
->u
.context
.u
.app_ctx
.provider_name_len
- 1
1306 + strlen(":") + lum
->u
.context
.u
.app_ctx
.ctx_name_len
;
1307 if (ctxlen
>= LTTNG_UST_ABI_SYM_NAME_LEN
) {
1308 ERR("Application context string length size is too large: %zu bytes",
1313 strcpy(ctxstr
, "$app.");
1314 p
= &ctxstr
[strlen("$app.")];
1315 recvlen
= ctxlen
- strlen("$app.");
1316 len
= ustcomm_recv_unix_sock(sock
, p
, recvlen
);
1318 case 0: /* orderly shutdown */
1322 if (len
== recvlen
) {
1323 DBG("app context data received");
1325 } else if (len
< 0) {
1326 DBG("Receive failed from lttng-sessiond with errno %d", (int) -len
);
1327 if (len
== -ECONNRESET
) {
1328 ERR("%s remote end closed connection", sock_info
->name
);
1335 DBG("incorrect app context data message size: %zd", len
);
1340 /* Put : between provider and ctxname. */
1341 p
[lum
->u
.context
.u
.app_ctx
.provider_name_len
- 1] = ':';
1342 args
.app_context
.ctxname
= ctxstr
;
1349 ret
= ops
->cmd(lum
->handle
, lum
->cmd
,
1350 (unsigned long) &lum
->u
,
1356 case LTTNG_UST_ABI_COUNTER
:
1360 len
= ustcomm_recv_counter_from_sessiond(sock
,
1361 &counter_data
, lum
->u
.counter
.len
);
1363 case 0: /* orderly shutdown */
1367 if (len
== lum
->u
.counter
.len
) {
1368 DBG("counter data received");
1370 } else if (len
< 0) {
1371 DBG("Receive failed from lttng-sessiond with errno %d", (int) -len
);
1372 if (len
== -ECONNRESET
) {
1373 ERR("%s remote end closed connection", sock_info
->name
);
1380 DBG("incorrect counter data message size: %zd", len
);
1385 args
.counter
.counter_data
= counter_data
;
1387 ret
= ops
->cmd(lum
->handle
, lum
->cmd
,
1388 (unsigned long) &lum
->u
,
1392 free(args
.counter
.counter_data
);
1395 case LTTNG_UST_ABI_COUNTER_GLOBAL
:
1397 /* Receive shm_fd */
1398 ret
= ustcomm_recv_counter_shm_from_sessiond(sock
,
1399 &args
.counter_shm
.shm_fd
);
1405 ret
= ops
->cmd(lum
->handle
, lum
->cmd
,
1406 (unsigned long) &lum
->u
,
1410 if (args
.counter_shm
.shm_fd
>= 0) {
1413 lttng_ust_lock_fd_tracker();
1414 close_ret
= close(args
.counter_shm
.shm_fd
);
1415 lttng_ust_unlock_fd_tracker();
1416 args
.counter_shm
.shm_fd
= -1;
1422 case LTTNG_UST_ABI_COUNTER_CPU
:
1424 /* Receive shm_fd */
1425 ret
= ustcomm_recv_counter_shm_from_sessiond(sock
,
1426 &args
.counter_shm
.shm_fd
);
1432 ret
= ops
->cmd(lum
->handle
, lum
->cmd
,
1433 (unsigned long) &lum
->u
,
1437 if (args
.counter_shm
.shm_fd
>= 0) {
1440 lttng_ust_lock_fd_tracker();
1441 close_ret
= close(args
.counter_shm
.shm_fd
);
1442 lttng_ust_unlock_fd_tracker();
1443 args
.counter_shm
.shm_fd
= -1;
1449 case LTTNG_UST_ABI_EVENT_NOTIFIER_CREATE
:
1451 /* Receive struct lttng_ust_event_notifier */
1452 struct lttng_ust_abi_event_notifier event_notifier
;
1454 if (sizeof(event_notifier
) != lum
->u
.event_notifier
.len
) {
1455 DBG("incorrect event notifier data message size: %u", lum
->u
.event_notifier
.len
);
1459 len
= ustcomm_recv_unix_sock(sock
, &event_notifier
, sizeof(event_notifier
));
1461 case 0: /* orderly shutdown */
1465 if (len
== sizeof(event_notifier
)) {
1466 DBG("event notifier data received");
1468 } else if (len
< 0) {
1469 DBG("Receive failed from lttng-sessiond with errno %d", (int) -len
);
1470 if (len
== -ECONNRESET
) {
1471 ERR("%s remote end closed connection", sock_info
->name
);
1478 DBG("incorrect event notifier data message size: %zd", len
);
1484 ret
= ops
->cmd(lum
->handle
, lum
->cmd
,
1485 (unsigned long) &event_notifier
,
1494 ret
= ops
->cmd(lum
->handle
, lum
->cmd
,
1495 (unsigned long) &lum
->u
,
1502 prepare_cmd_reply(&lur
, lum
->handle
, lum
->cmd
, ret
);
1506 case LTTNG_UST_ABI_TRACER_VERSION
:
1507 lur
.u
.version
= lum
->u
.version
;
1509 case LTTNG_UST_ABI_TRACEPOINT_LIST_GET
:
1510 memcpy(&lur
.u
.tracepoint
, &lum
->u
.tracepoint
, sizeof(lur
.u
.tracepoint
));
1514 DBG("Return value: %d", lur
.ret_val
);
1519 * Performed delayed statedump operations outside of the UST
1520 * lock. We need to take the dynamic loader lock before we take
1521 * the UST lock internally within handle_pending_statedump().
1523 handle_pending_statedump(sock_info
);
1526 ret
= -LTTNG_UST_ERR_EXITING
;
1530 ret
= send_reply(sock
, &lur
);
1532 DBG("error sending reply");
1537 * LTTNG_UST_TRACEPOINT_FIELD_LIST_GET needs to send the field
1540 if (lur
.ret_code
== LTTNG_UST_OK
) {
1542 case LTTNG_UST_ABI_TRACEPOINT_FIELD_LIST_GET
:
1543 len
= ustcomm_send_unix_sock(sock
,
1544 &args
.field_list
.entry
,
1545 sizeof(args
.field_list
.entry
));
1550 if (len
!= sizeof(args
.field_list
.entry
)) {
1564 void cleanup_sock_info(struct sock_info
*sock_info
, int exiting
)
1568 if (sock_info
->root_handle
!= -1) {
1569 ret
= lttng_ust_abi_objd_unref(sock_info
->root_handle
, 1);
1571 ERR("Error unref root handle");
1573 sock_info
->root_handle
= -1;
1578 * wait_shm_mmap, socket and notify socket are used by listener
1579 * threads outside of the ust lock, so we cannot tear them down
1580 * ourselves, because we cannot join on these threads. Leave
1581 * responsibility of cleaning up these resources to the OS
1587 sock_info
->registration_done
= 0;
1588 sock_info
->initial_statedump_done
= 0;
1590 if (sock_info
->socket
!= -1) {
1591 ret
= ustcomm_close_unix_sock(sock_info
->socket
);
1593 ERR("Error closing ust cmd socket");
1595 sock_info
->socket
= -1;
1597 if (sock_info
->notify_socket
!= -1) {
1598 ret
= ustcomm_close_unix_sock(sock_info
->notify_socket
);
1600 ERR("Error closing ust notify socket");
1602 sock_info
->notify_socket
= -1;
1604 if (sock_info
->wait_shm_mmap
) {
1607 page_size
= LTTNG_UST_PAGE_SIZE
;
1608 if (page_size
<= 0) {
1612 PERROR("Error in sysconf(_SC_PAGE_SIZE)");
1614 ret
= munmap(sock_info
->wait_shm_mmap
, page_size
);
1616 ERR("Error unmapping wait shm");
1619 sock_info
->wait_shm_mmap
= NULL
;
1624 int wait_shm_open(struct sock_info
*sock_info
, int flags
, mode_t mode
)
1626 if (sock_info
->wait_shm_is_file
)
1627 return open(sock_info
->wait_shm_path
, flags
, mode
);
1629 return shm_open(sock_info
->wait_shm_path
, flags
, mode
);
1633 * Using fork to set umask in the child process (not multi-thread safe).
1634 * We deal with the shm_open vs ftruncate race (happening when the
1635 * sessiond owns the shm and does not let everybody modify it, to ensure
1636 * safety against shm_unlink) by simply letting the mmap fail and
1637 * retrying after a few seconds.
1638 * For global shm, everybody has rw access to it until the sessiond
1642 int get_wait_shm(struct sock_info
*sock_info
, size_t mmap_size
)
1644 int wait_shm_fd
, ret
;
1648 * Try to open read-only.
1650 wait_shm_fd
= wait_shm_open(sock_info
, O_RDONLY
, 0);
1651 if (wait_shm_fd
>= 0) {
1654 size_t bytes_read
= 0;
1657 * Try to read the fd. If unable to do so, try opening
1661 len
= read(wait_shm_fd
,
1662 &((char *) &tmp_read
)[bytes_read
],
1663 sizeof(tmp_read
) - bytes_read
);
1667 } while ((len
< 0 && errno
== EINTR
)
1668 || (len
> 0 && bytes_read
< sizeof(tmp_read
)));
1669 if (bytes_read
!= sizeof(tmp_read
)) {
1670 ret
= close(wait_shm_fd
);
1672 ERR("close wait_shm_fd");
1677 } else if (wait_shm_fd
< 0 && errno
!= ENOENT
) {
1679 * Real-only open did not work, and it's not because the
1680 * entry was not present. It's a failure that prohibits
1683 ERR("Error opening shm %s", sock_info
->wait_shm_path
);
1689 * If the open failed because the file did not exist, or because
1690 * the file was not truncated yet, try creating it ourself.
1692 URCU_TLS(lttng_ust_nest_count
)++;
1694 URCU_TLS(lttng_ust_nest_count
)--;
1696 int status
, wait_ret
;
1699 * Parent: wait for child to return, in which case the
1700 * shared memory map will have been created.
1702 wait_ret
= waitpid(pid
, &status
, 0);
1703 if (wait_ret
< 0 || !WIFEXITED(status
) || WEXITSTATUS(status
) != 0) {
1708 * Try to open read-only again after creation.
1710 wait_shm_fd
= wait_shm_open(sock_info
, O_RDONLY
, 0);
1711 if (wait_shm_fd
< 0) {
1713 * Real-only open did not work. It's a failure
1714 * that prohibits using shm.
1716 ERR("Error opening shm %s", sock_info
->wait_shm_path
);
1720 } else if (pid
== 0) {
1724 create_mode
= S_IRUSR
| S_IWUSR
| S_IRGRP
;
1725 if (sock_info
->multi_user
)
1726 create_mode
|= S_IROTH
| S_IWGRP
| S_IWOTH
;
1728 * We're alone in a child process, so we can modify the
1729 * process-wide umask.
1731 umask(~create_mode
);
1733 * Try creating shm (or get rw access).
1734 * We don't do an exclusive open, because we allow other
1735 * processes to create+ftruncate it concurrently.
1737 wait_shm_fd
= wait_shm_open(sock_info
,
1738 O_RDWR
| O_CREAT
, create_mode
);
1739 if (wait_shm_fd
>= 0) {
1740 ret
= ftruncate(wait_shm_fd
, mmap_size
);
1742 PERROR("ftruncate");
1743 _exit(EXIT_FAILURE
);
1745 _exit(EXIT_SUCCESS
);
1748 * For local shm, we need to have rw access to accept
1749 * opening it: this means the local sessiond will be
1750 * able to wake us up. For global shm, we open it even
1751 * if rw access is not granted, because the root.root
1752 * sessiond will be able to override all rights and wake
1755 if (!sock_info
->multi_user
&& errno
!= EACCES
) {
1756 ERR("Error opening shm %s", sock_info
->wait_shm_path
);
1757 _exit(EXIT_FAILURE
);
1760 * The shm exists, but we cannot open it RW. Report
1763 _exit(EXIT_SUCCESS
);
1768 if (wait_shm_fd
>= 0 && !sock_info
->multi_user
) {
1769 struct stat statbuf
;
1772 * Ensure that our user is the owner of the shm file for
1773 * local shm. If we do not own the file, it means our
1774 * sessiond will not have access to wake us up (there is
1775 * probably a rogue process trying to fake our
1776 * sessiond). Fallback to polling method in this case.
1778 ret
= fstat(wait_shm_fd
, &statbuf
);
1783 if (statbuf
.st_uid
!= getuid())
1789 ret
= close(wait_shm_fd
);
1791 PERROR("Error closing fd");
1797 char *get_map_shm(struct sock_info
*sock_info
)
1800 int wait_shm_fd
, ret
;
1801 char *wait_shm_mmap
;
1803 page_size
= sysconf(_SC_PAGE_SIZE
);
1804 if (page_size
<= 0) {
1808 PERROR("Error in sysconf(_SC_PAGE_SIZE)");
1812 lttng_ust_lock_fd_tracker();
1813 wait_shm_fd
= get_wait_shm(sock_info
, page_size
);
1814 if (wait_shm_fd
< 0) {
1815 lttng_ust_unlock_fd_tracker();
1819 ret
= lttng_ust_add_fd_to_tracker(wait_shm_fd
);
1821 ret
= close(wait_shm_fd
);
1823 PERROR("Error closing fd");
1825 lttng_ust_unlock_fd_tracker();
1830 lttng_ust_unlock_fd_tracker();
1832 wait_shm_mmap
= mmap(NULL
, page_size
, PROT_READ
,
1833 MAP_SHARED
, wait_shm_fd
, 0);
1835 /* close shm fd immediately after taking the mmap reference */
1836 lttng_ust_lock_fd_tracker();
1837 ret
= close(wait_shm_fd
);
1839 lttng_ust_delete_fd_from_tracker(wait_shm_fd
);
1841 PERROR("Error closing fd");
1843 lttng_ust_unlock_fd_tracker();
1845 if (wait_shm_mmap
== MAP_FAILED
) {
1846 DBG("mmap error (can be caused by race with sessiond). Fallback to poll mode.");
1849 return wait_shm_mmap
;
1856 void wait_for_sessiond(struct sock_info
*sock_info
)
1858 /* Use ust_lock to check if we should quit. */
1862 if (wait_poll_fallback
) {
1867 assert(sock_info
->wait_shm_mmap
);
1869 DBG("Waiting for %s apps sessiond", sock_info
->name
);
1870 /* Wait for futex wakeup */
1871 while (!uatomic_read((int32_t *) sock_info
->wait_shm_mmap
)) {
1872 if (!lttng_ust_futex_async((int32_t *) sock_info
->wait_shm_mmap
, FUTEX_WAIT
, 0, NULL
, NULL
, 0)) {
1874 * Prior queued wakeups queued by unrelated code
1875 * using the same address can cause futex wait to
1876 * return 0 even through the futex value is still
1877 * 0 (spurious wakeups). Check the value again
1878 * in user-space to validate whether it really
1885 /* Value already changed. */
1888 /* Retry if interrupted by signal. */
1889 break; /* Get out of switch. Check again. */
1891 wait_poll_fallback
= 1;
1893 "Linux kernels 2.6.33 to 3.0 (with the exception of stable versions) "
1894 "do not support FUTEX_WAKE on read-only memory mappings correctly. "
1895 "Please upgrade your kernel "
1896 "(fix is commit 9ea71503a8ed9184d2d0b8ccc4d269d05f7940ae in Linux kernel "
1897 "mainline). LTTng-UST will use polling mode fallback.");
1898 if (lttng_ust_logging_debug_enabled())
1916 * This thread does not allocate any resource, except within
1917 * handle_message, within mutex protection. This mutex protects against
1919 * The other moment it allocates resources is at socket connection, which
1920 * is also protected by the mutex.
1923 void *ust_listener_thread(void *arg
)
1925 struct sock_info
*sock_info
= arg
;
1926 int sock
, ret
, prev_connect_failed
= 0, has_waited
= 0, fd
;
1929 lttng_ust_common_init_thread(0);
1931 * If available, add '-ust' to the end of this thread's
1934 ret
= lttng_ust_setustprocname();
1936 ERR("Unable to set UST process name");
1939 /* Restart trying to connect to the session daemon */
1941 if (prev_connect_failed
) {
1942 /* Wait for sessiond availability with pipe */
1943 wait_for_sessiond(sock_info
);
1947 * Sleep for 5 seconds before retrying after a
1948 * sequence of failure / wait / failure. This
1949 * deals with a killed or broken session daemon.
1955 prev_connect_failed
= 0;
1962 if (sock_info
->socket
!= -1) {
1963 /* FD tracker is updated by ustcomm_close_unix_sock() */
1964 ret
= ustcomm_close_unix_sock(sock_info
->socket
);
1966 ERR("Error closing %s ust cmd socket",
1969 sock_info
->socket
= -1;
1971 if (sock_info
->notify_socket
!= -1) {
1972 /* FD tracker is updated by ustcomm_close_unix_sock() */
1973 ret
= ustcomm_close_unix_sock(sock_info
->notify_socket
);
1975 ERR("Error closing %s ust notify socket",
1978 sock_info
->notify_socket
= -1;
1983 * Register. We need to perform both connect and sending
1984 * registration message before doing the next connect otherwise
1985 * we may reach unix socket connect queue max limits and block
1986 * on the 2nd connect while the session daemon is awaiting the
1987 * first connect registration message.
1989 /* Connect cmd socket */
1990 lttng_ust_lock_fd_tracker();
1991 ret
= ustcomm_connect_unix_sock(sock_info
->sock_path
,
1992 get_connect_sock_timeout());
1994 lttng_ust_unlock_fd_tracker();
1995 DBG("Info: sessiond not accepting connections to %s apps socket", sock_info
->name
);
1996 prev_connect_failed
= 1;
1999 * If we cannot find the sessiond daemon, don't delay
2000 * constructor execution.
2002 ret
= handle_register_failed(sock_info
);
2008 ret
= lttng_ust_add_fd_to_tracker(fd
);
2012 PERROR("close on sock_info->socket");
2015 lttng_ust_unlock_fd_tracker();
2020 sock_info
->socket
= ret
;
2021 lttng_ust_unlock_fd_tracker();
2025 * Unlock/relock ust lock because connect is blocking (with
2026 * timeout). Don't delay constructors on the ust lock for too
2034 * Create only one root handle per listener thread for the whole
2035 * process lifetime, so we ensure we get ID which is statically
2036 * assigned to the root handle.
2038 if (sock_info
->root_handle
== -1) {
2039 ret
= lttng_abi_create_root_handle();
2041 ERR("Error creating root handle");
2044 sock_info
->root_handle
= ret
;
2047 ret
= register_to_sessiond(sock_info
->socket
, LTTNG_UST_CTL_SOCKET_CMD
,
2048 sock_info
->procname
);
2050 ERR("Error registering to %s ust cmd socket",
2052 prev_connect_failed
= 1;
2054 * If we cannot register to the sessiond daemon, don't
2055 * delay constructor execution.
2057 ret
= handle_register_failed(sock_info
);
2065 * Unlock/relock ust lock because connect is blocking (with
2066 * timeout). Don't delay constructors on the ust lock for too
2073 /* Connect notify socket */
2074 lttng_ust_lock_fd_tracker();
2075 ret
= ustcomm_connect_unix_sock(sock_info
->sock_path
,
2076 get_connect_sock_timeout());
2078 lttng_ust_unlock_fd_tracker();
2079 DBG("Info: sessiond not accepting connections to %s apps socket", sock_info
->name
);
2080 prev_connect_failed
= 1;
2083 * If we cannot find the sessiond daemon, don't delay
2084 * constructor execution.
2086 ret
= handle_register_failed(sock_info
);
2093 ret
= lttng_ust_add_fd_to_tracker(fd
);
2097 PERROR("close on sock_info->notify_socket");
2100 lttng_ust_unlock_fd_tracker();
2105 sock_info
->notify_socket
= ret
;
2106 lttng_ust_unlock_fd_tracker();
2110 * Unlock/relock ust lock because connect is blocking (with
2111 * timeout). Don't delay constructors on the ust lock for too
2118 timeout
= get_notify_sock_timeout();
2121 * Give at least 10ms to sessiond to reply to
2126 ret
= ustcomm_setsockopt_rcv_timeout(sock_info
->notify_socket
,
2129 WARN("Error setting socket receive timeout");
2131 ret
= ustcomm_setsockopt_snd_timeout(sock_info
->notify_socket
,
2134 WARN("Error setting socket send timeout");
2136 } else if (timeout
< -1) {
2137 WARN("Unsupported timeout value %ld", timeout
);
2140 ret
= register_to_sessiond(sock_info
->notify_socket
,
2141 LTTNG_UST_CTL_SOCKET_NOTIFY
, sock_info
->procname
);
2143 ERR("Error registering to %s ust notify socket",
2145 prev_connect_failed
= 1;
2147 * If we cannot register to the sessiond daemon, don't
2148 * delay constructor execution.
2150 ret
= handle_register_failed(sock_info
);
2155 sock
= sock_info
->socket
;
2161 struct ustcomm_ust_msg lum
;
2163 len
= ustcomm_recv_unix_sock(sock
, &lum
, sizeof(lum
));
2165 case 0: /* orderly shutdown */
2166 DBG("%s lttng-sessiond has performed an orderly shutdown", sock_info
->name
);
2171 * Either sessiond has shutdown or refused us by closing the socket.
2172 * In either case, we don't want to delay construction execution,
2173 * and we need to wait before retry.
2175 prev_connect_failed
= 1;
2177 * If we cannot register to the sessiond daemon, don't
2178 * delay constructor execution.
2180 ret
= handle_register_failed(sock_info
);
2185 print_cmd(lum
.cmd
, lum
.handle
);
2186 ret
= handle_message(sock_info
, sock
, &lum
);
2188 ERR("Error handling message for %s socket",
2191 * Close socket if protocol error is
2199 DBG("Receive failed from lttng-sessiond with errno %d", (int) -len
);
2201 DBG("incorrect message size (%s socket): %zd", sock_info
->name
, len
);
2203 if (len
== -ECONNRESET
) {
2204 DBG("%s remote end closed connection", sock_info
->name
);
2215 /* Cleanup socket handles before trying to reconnect */
2216 lttng_ust_abi_objd_table_owner_cleanup(sock_info
);
2218 goto restart
; /* try to reconnect */
2223 pthread_mutex_lock(&ust_exit_mutex
);
2224 sock_info
->thread_active
= 0;
2225 pthread_mutex_unlock(&ust_exit_mutex
);
2230 * Weak symbol to call when the ust malloc wrapper is not loaded.
2232 __attribute__((weak
))
2233 void lttng_ust_libc_wrapper_malloc_ctor(void)
2238 * Use a symbol of the previous ABI to detect if liblttng-ust.so.0 is loaded in
2239 * the current process.
2241 #define LTTNG_UST_SONAME_0_SYM "ltt_probe_register"
2244 void lttng_ust_check_soname_0(void)
2246 if (!dlsym(RTLD_DEFAULT
, LTTNG_UST_SONAME_0_SYM
))
2249 CRIT("Incompatible library ABIs detected within the same process. "
2250 "The process is likely linked against different major soname of LTTng-UST which is unsupported. "
2251 "The detection was triggered by lookup of ABI 0 symbol \"%s\" in the Global Symbol Table\n",
2252 LTTNG_UST_SONAME_0_SYM
);
2256 * Expose a canary symbol of the previous ABI to ensure we catch uses of a
2257 * liblttng-ust.so.0 dlopen'd after .so.1 has been loaded. Use a different
2258 * symbol than the detection code to ensure we don't detect ourself.
2260 * This scheme will only work on systems where the global symbol table has
2261 * priority when resolving the symbols of a dlopened shared object, which is
2262 * the case on Linux but not on FreeBSD.
2264 void init_usterr(void);
2265 void init_usterr(void)
2267 CRIT("Incompatible library ABIs detected within the same process. "
2268 "The process is likely linked against different major soname of LTTng-UST which is unsupported. "
2269 "The detection was triggered by canary symbol \"%s\"\n", __func__
);
2273 * sessiond monitoring thread: monitor presence of global and per-user
2274 * sessiond by polling the application common named pipe.
2277 void lttng_ust_ctor(void)
2278 __attribute__((constructor
));
2280 void lttng_ust_ctor(void)
2282 struct timespec constructor_timeout
;
2283 sigset_t sig_all_blocked
, orig_parent_mask
;
2284 pthread_attr_t thread_attr
;
2289 if (uatomic_xchg(&initialized
, 1) == 1)
2293 * Fixup interdependency between TLS allocation mutex (which happens
2294 * to be the dynamic linker mutex) and ust_lock, taken within
2297 lttng_ust_common_init_thread(0);
2299 lttng_ust_loaded
= 1;
2302 * Check if we find a symbol of the previous ABI in the current process
2303 * as different ABIs of liblttng-ust can't co-exist in a process. If we
2304 * do so, emit a critical log message which will also abort if the
2305 * LTTNG_UST_ABORT_ON_CRITICAL environment variable is set.
2307 lttng_ust_check_soname_0();
2310 * We need to ensure that the liblttng-ust library is not unloaded to avoid
2311 * the unloading of code used by the ust_listener_threads as we can not
2312 * reliably know when they exited. To do that, manually load
2313 * liblttng-ust.so to increment the dynamic loader's internal refcount for
2314 * this library so it never becomes zero, thus never gets unloaded from the
2315 * address space of the process. Since we are already running in the
2316 * constructor of the LTTNG_UST_LIB_SONAME library, calling dlopen will
2317 * simply increment the refcount and no additional work is needed by the
2318 * dynamic loader as the shared library is already loaded in the address
2319 * space. As a safe guard, we use the RTLD_NODELETE flag to prevent
2320 * unloading of the UST library if its refcount becomes zero (which should
2321 * never happen). Do the return value check but discard the handle at the
2322 * end of the function as it's not needed.
2324 handle
= dlopen(LTTNG_UST_LIB_SONAME
, RTLD_LAZY
| RTLD_NODELETE
);
2326 ERR("dlopen of liblttng-ust shared library (%s).", LTTNG_UST_LIB_SONAME
);
2328 DBG("dlopened liblttng-ust shared library (%s).", LTTNG_UST_LIB_SONAME
);
2332 * We want precise control over the order in which we construct
2333 * our sub-libraries vs starting to receive commands from
2334 * sessiond (otherwise leading to errors when trying to create
2335 * sessiond before the init functions are completed).
2339 * Both the logging and getenv lazy-initialization uses getenv()
2340 * internally and thus needs to be explicitly initialized in
2341 * liblttng-ust before we start any threads as an unsuspecting normally
2342 * single threaded application using liblttng-ust could be using
2343 * setenv() which is not thread-safe.
2345 lttng_ust_logging_init();
2346 lttng_ust_getenv_init();
2348 /* Call the liblttng-ust-common constructor. */
2349 lttng_ust_common_ctor();
2351 lttng_ust_tp_init();
2352 lttng_ust_statedump_init();
2353 lttng_ust_ring_buffer_clients_init();
2354 lttng_ust_counter_clients_init();
2355 lttng_perf_counter_init();
2357 * Invoke ust malloc wrapper init before starting other threads.
2359 lttng_ust_libc_wrapper_malloc_ctor();
2361 timeout_mode
= get_constructor_timeout(&constructor_timeout
);
2363 get_allow_blocking();
2365 ret
= sem_init(&constructor_wait
, 0, 0);
2370 ret
= setup_ust_apps();
2372 assert(ust_app
.allowed
== 0);
2373 DBG("ust_app setup returned %d", ret
);
2375 ret
= setup_global_apps();
2377 assert(global_apps
.allowed
== 0);
2378 DBG("global apps setup returned %d", ret
);
2381 ret
= setup_local_apps();
2383 assert(local_apps
.allowed
== 0);
2384 DBG("local apps setup returned %d", ret
);
2387 /* A new thread created by pthread_create inherits the signal mask
2388 * from the parent. To avoid any signal being received by the
2389 * listener thread, we block all signals temporarily in the parent,
2390 * while we create the listener thread.
2392 sigfillset(&sig_all_blocked
);
2393 ret
= pthread_sigmask(SIG_SETMASK
, &sig_all_blocked
, &orig_parent_mask
);
2395 ERR("pthread_sigmask: %s", strerror(ret
));
2398 ret
= pthread_attr_init(&thread_attr
);
2400 ERR("pthread_attr_init: %s", strerror(ret
));
2402 ret
= pthread_attr_setdetachstate(&thread_attr
, PTHREAD_CREATE_DETACHED
);
2404 ERR("pthread_attr_setdetachstate: %s", strerror(ret
));
2407 if (ust_app
.allowed
) {
2408 pthread_mutex_lock(&ust_exit_mutex
);
2409 ret
= pthread_create(&ust_app
.ust_listener
, &thread_attr
,
2410 ust_listener_thread
, &ust_app
);
2412 ERR("pthread_create ust_app: %s", strerror(ret
));
2414 ust_app
.thread_active
= 1;
2415 pthread_mutex_unlock(&ust_exit_mutex
);
2417 handle_register_done(&ust_app
);
2420 if (global_apps
.allowed
) {
2421 pthread_mutex_lock(&ust_exit_mutex
);
2422 ret
= pthread_create(&global_apps
.ust_listener
, &thread_attr
,
2423 ust_listener_thread
, &global_apps
);
2425 ERR("pthread_create global: %s", strerror(ret
));
2427 global_apps
.thread_active
= 1;
2428 pthread_mutex_unlock(&ust_exit_mutex
);
2430 handle_register_done(&global_apps
);
2433 if (local_apps
.allowed
) {
2434 pthread_mutex_lock(&ust_exit_mutex
);
2435 ret
= pthread_create(&local_apps
.ust_listener
, &thread_attr
,
2436 ust_listener_thread
, &local_apps
);
2438 ERR("pthread_create local: %s", strerror(ret
));
2440 local_apps
.thread_active
= 1;
2441 pthread_mutex_unlock(&ust_exit_mutex
);
2443 handle_register_done(&local_apps
);
2445 ret
= pthread_attr_destroy(&thread_attr
);
2447 ERR("pthread_attr_destroy: %s", strerror(ret
));
2450 /* Restore original signal mask in parent */
2451 ret
= pthread_sigmask(SIG_SETMASK
, &orig_parent_mask
, NULL
);
2453 ERR("pthread_sigmask: %s", strerror(ret
));
2456 switch (timeout_mode
) {
2457 case 1: /* timeout wait */
2459 ret
= sem_timedwait(&constructor_wait
,
2460 &constructor_timeout
);
2461 } while (ret
< 0 && errno
== EINTR
);
2465 ERR("Timed out waiting for lttng-sessiond");
2468 PERROR("sem_timedwait");
2471 ERR("Unexpected error \"%s\" returned by sem_timedwait",
2476 case -1:/* wait forever */
2478 ret
= sem_wait(&constructor_wait
);
2479 } while (ret
< 0 && errno
== EINTR
);
2486 ERR("Unexpected error \"%s\" returned by sem_wait",
2491 case 0: /* no timeout */
2497 void lttng_ust_cleanup(int exiting
)
2499 cleanup_sock_info(&ust_app
, exiting
);
2500 cleanup_sock_info(&global_apps
, exiting
);
2501 cleanup_sock_info(&local_apps
, exiting
);
2502 ust_app
.allowed
= 0;
2503 local_apps
.allowed
= 0;
2504 global_apps
.allowed
= 0;
2506 * The teardown in this function all affect data structures
2507 * accessed under the UST lock by the listener thread. This
2508 * lock, along with the lttng_ust_comm_should_quit flag, ensure
2509 * that none of these threads are accessing this data at this
2512 lttng_ust_abi_exit();
2513 lttng_ust_abi_events_exit();
2514 lttng_perf_counter_exit();
2515 lttng_ust_ring_buffer_clients_exit();
2516 lttng_ust_counter_clients_exit();
2517 lttng_ust_statedump_destroy();
2518 lttng_ust_tp_exit();
2520 /* Reinitialize values for fork */
2521 sem_count
= sem_count_initial_value
;
2522 lttng_ust_comm_should_quit
= 0;
2528 void lttng_ust_exit(void)
2529 __attribute__((destructor
));
2531 void lttng_ust_exit(void)
2536 * Using pthread_cancel here because:
2537 * A) we don't want to hang application teardown.
2538 * B) the thread is not allocating any resource.
2542 * Require the communication thread to quit. Synchronize with
2543 * mutexes to ensure it is not in a mutex critical section when
2544 * pthread_cancel is later called.
2547 lttng_ust_comm_should_quit
= 1;
2550 pthread_mutex_lock(&ust_exit_mutex
);
2551 /* cancel threads */
2552 if (ust_app
.thread_active
) {
2553 ret
= pthread_cancel(ust_app
.ust_listener
);
2555 ERR("Error cancelling ust listener thread: %s",
2558 ust_app
.thread_active
= 0;
2561 if (global_apps
.thread_active
) {
2562 ret
= pthread_cancel(global_apps
.ust_listener
);
2564 ERR("Error cancelling global ust listener thread: %s",
2567 global_apps
.thread_active
= 0;
2570 if (local_apps
.thread_active
) {
2571 ret
= pthread_cancel(local_apps
.ust_listener
);
2573 ERR("Error cancelling local ust listener thread: %s",
2576 local_apps
.thread_active
= 0;
2579 pthread_mutex_unlock(&ust_exit_mutex
);
2582 * Do NOT join threads: use of sys_futex makes it impossible to
2583 * join the threads without using async-cancel, but async-cancel
2584 * is delivered by a signal, which could hit the target thread
2585 * anywhere in its code path, including while the ust_lock() is
2586 * held, causing a deadlock for the other thread. Let the OS
2587 * cleanup the threads if there are stalled in a syscall.
2589 lttng_ust_cleanup(1);
2593 void ust_context_ns_reset(void)
2595 lttng_context_pid_ns_reset();
2596 lttng_context_cgroup_ns_reset();
2597 lttng_context_ipc_ns_reset();
2598 lttng_context_mnt_ns_reset();
2599 lttng_context_net_ns_reset();
2600 lttng_context_user_ns_reset();
2601 lttng_context_time_ns_reset();
2602 lttng_context_uts_ns_reset();
2606 void ust_context_vuids_reset(void)
2608 lttng_context_vuid_reset();
2609 lttng_context_veuid_reset();
2610 lttng_context_vsuid_reset();
2614 void ust_context_vgids_reset(void)
2616 lttng_context_vgid_reset();
2617 lttng_context_vegid_reset();
2618 lttng_context_vsgid_reset();
2622 * We exclude the worker threads across fork and clone (except
2623 * CLONE_VM), because these system calls only keep the forking thread
2624 * running in the child. Therefore, we don't want to call fork or clone
2625 * in the middle of an tracepoint or ust tracing state modification.
2626 * Holding this mutex protects these structures across fork and clone.
2628 void lttng_ust_before_fork(sigset_t
*save_sigset
)
2631 * Disable signals. This is to avoid that the child intervenes
2632 * before it is properly setup for tracing. It is safer to
2633 * disable all signals, because then we know we are not breaking
2634 * anything by restoring the original mask.
2639 /* Allocate lttng-ust TLS. */
2640 lttng_ust_common_init_thread(0);
2642 if (URCU_TLS(lttng_ust_nest_count
))
2644 /* Disable signals */
2645 sigfillset(&all_sigs
);
2646 ret
= sigprocmask(SIG_BLOCK
, &all_sigs
, save_sigset
);
2648 PERROR("sigprocmask");
2651 pthread_mutex_lock(&ust_fork_mutex
);
2654 lttng_ust_urcu_before_fork();
2655 lttng_ust_lock_fd_tracker();
2659 static void ust_after_fork_common(sigset_t
*restore_sigset
)
2663 DBG("process %d", getpid());
2664 lttng_perf_unlock();
2665 lttng_ust_unlock_fd_tracker();
2668 pthread_mutex_unlock(&ust_fork_mutex
);
2670 /* Restore signals */
2671 ret
= sigprocmask(SIG_SETMASK
, restore_sigset
, NULL
);
2673 PERROR("sigprocmask");
2677 void lttng_ust_after_fork_parent(sigset_t
*restore_sigset
)
2679 if (URCU_TLS(lttng_ust_nest_count
))
2681 DBG("process %d", getpid());
2682 lttng_ust_urcu_after_fork_parent();
2683 /* Release mutexes and re-enable signals */
2684 ust_after_fork_common(restore_sigset
);
2688 * After fork, in the child, we need to cleanup all the leftover state,
2689 * except the worker thread which already magically disappeared thanks
2690 * to the weird Linux fork semantics. After tyding up, we call
2691 * lttng_ust_ctor() again to start over as a new PID.
2693 * This is meant for forks() that have tracing in the child between the
2694 * fork and following exec call (if there is any).
2696 void lttng_ust_after_fork_child(sigset_t
*restore_sigset
)
2698 if (URCU_TLS(lttng_ust_nest_count
))
2700 lttng_context_vpid_reset();
2701 lttng_context_vtid_reset();
2702 lttng_ust_context_procname_reset();
2703 ust_context_ns_reset();
2704 ust_context_vuids_reset();
2705 ust_context_vgids_reset();
2706 DBG("process %d", getpid());
2707 /* Release urcu mutexes */
2708 lttng_ust_urcu_after_fork_child();
2709 lttng_ust_cleanup(0);
2710 /* Release mutexes and re-enable signals */
2711 ust_after_fork_common(restore_sigset
);
2715 void lttng_ust_after_setns(void)
2717 ust_context_ns_reset();
2718 ust_context_vuids_reset();
2719 ust_context_vgids_reset();
2722 void lttng_ust_after_unshare(void)
2724 ust_context_ns_reset();
2725 ust_context_vuids_reset();
2726 ust_context_vgids_reset();
2729 void lttng_ust_after_setuid(void)
2731 ust_context_vuids_reset();
2734 void lttng_ust_after_seteuid(void)
2736 ust_context_vuids_reset();
2739 void lttng_ust_after_setreuid(void)
2741 ust_context_vuids_reset();
2744 void lttng_ust_after_setresuid(void)
2746 ust_context_vuids_reset();
2749 void lttng_ust_after_setgid(void)
2751 ust_context_vgids_reset();
2754 void lttng_ust_after_setegid(void)
2756 ust_context_vgids_reset();
2759 void lttng_ust_after_setregid(void)
2761 ust_context_vgids_reset();
2764 void lttng_ust_after_setresgid(void)
2766 ust_context_vgids_reset();
2769 void lttng_ust_sockinfo_session_enabled(void *owner
)
2771 struct sock_info
*sock_info
= owner
;
2772 sock_info
->statedump_pending
= 1;