X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Ftracepoint.c;h=8d41d97a7793c79f56a9a1d9cc51c4f9b2f60fd6;hb=d10a220587d0a41c85da916a65e9dfc9f61062fa;hp=b109fe30152b2968f7aba03736bab0cae53dbd89;hpb=d6ddec3f8a747381dfb2af999731b83379713960;p=lttng-ust.git diff --git a/liblttng-ust/tracepoint.c b/liblttng-ust/tracepoint.c index b109fe30..8d41d97a 100644 --- a/liblttng-ust/tracepoint.c +++ b/liblttng-ust/tracepoint.c @@ -1,21 +1,9 @@ /* + * SPDX-License-Identifier: LGPL-2.1-only + * * Copyright (C) 2008-2011 Mathieu Desnoyers * Copyright (C) 2009 Pierre-Marc Fournier * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; - * version 2.1 of the License. - * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - * * Ported to userspace by Pierre-Marc Fournier. */ @@ -26,17 +14,17 @@ #include #include -#include +#include #include #include #include #include #include -#include /* for LTTNG_UST_SYM_NAME_LEN */ +#include /* for LTTNG_UST_ABI_SYM_NAME_LEN */ #include -#include +#include #include "tracepoint-internal.h" #include "lttng-tracer-core.h" @@ -60,15 +48,6 @@ static int initialized; */ static int tracepoint_destructors_state = 1; -/* - * Expose the now deprecated symbol __tracepoints__disable_destructors for - * backward compatibility of applications built against old versions of - * lttng-ust. We need to keep __tracepoints__disable_destructors up to date - * within the new destructor disabling API because old applications read this - * symbol directly. - */ -int __tracepoints__disable_destructors __attribute__((weak)); - static void (*new_tracepoint_cb)(struct lttng_ust_tracepoint *); /* @@ -166,7 +145,7 @@ static void release_probes(void *old) if (old) { struct tp_probes *tp_probes = caa_container_of(old, struct tp_probes, probes[0]); - urcu_bp_synchronize_rcu(); + lttng_ust_urcu_synchronize_rcu(); free(tp_probes); } } @@ -277,14 +256,14 @@ static struct tracepoint_entry *get_tracepoint(const char *name) size_t name_len = strlen(name); uint32_t hash; - if (name_len > LTTNG_UST_SYM_NAME_LEN - 1) { - WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_SYM_NAME_LEN - 1); - name_len = LTTNG_UST_SYM_NAME_LEN - 1; + if (name_len > LTTNG_UST_ABI_SYM_NAME_LEN - 1) { + WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_ABI_SYM_NAME_LEN - 1); + name_len = LTTNG_UST_ABI_SYM_NAME_LEN - 1; } hash = jhash(name, name_len, 0); head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)]; cds_hlist_for_each_entry(e, node, head, hlist) { - if (!strncmp(name, e->name, LTTNG_UST_SYM_NAME_LEN - 1)) + if (!strncmp(name, e->name, LTTNG_UST_ABI_SYM_NAME_LEN - 1)) return e; } return NULL; @@ -305,14 +284,14 @@ static struct tracepoint_entry *add_tracepoint(const char *name, size_t sig_off, name_off; uint32_t hash; - if (name_len > LTTNG_UST_SYM_NAME_LEN - 1) { - WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_SYM_NAME_LEN - 1); - name_len = LTTNG_UST_SYM_NAME_LEN - 1; + if (name_len > LTTNG_UST_ABI_SYM_NAME_LEN - 1) { + WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_ABI_SYM_NAME_LEN - 1); + name_len = LTTNG_UST_ABI_SYM_NAME_LEN - 1; } hash = jhash(name, name_len, 0); head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)]; cds_hlist_for_each_entry(e, node, head, hlist) { - if (!strncmp(name, e->name, LTTNG_UST_SYM_NAME_LEN - 1)) { + if (!strncmp(name, e->name, LTTNG_UST_ABI_SYM_NAME_LEN - 1)) { DBG("tracepoint %s busy", name); return ERR_PTR(-EEXIST); /* Already there */ } @@ -360,7 +339,7 @@ static void remove_tracepoint(struct tracepoint_entry *e) static void set_tracepoint(struct tracepoint_entry **entry, struct lttng_ust_tracepoint *elem, int active) { - WARN_ON(strncmp((*entry)->name, elem->name, LTTNG_UST_SYM_NAME_LEN - 1) != 0); + WARN_ON(strncmp((*entry)->name, elem->name, LTTNG_UST_ABI_SYM_NAME_LEN - 1) != 0); /* * Check that signatures match before connecting a probe to a * tracepoint. Warn the user if they don't. @@ -386,7 +365,7 @@ static void set_tracepoint(struct tracepoint_entry **entry, * include/linux/tracepoints.h. A matching cmm_smp_read_barrier_depends() * is used. */ - rcu_assign_pointer(elem->probes, (*entry)->probes); + lttng_ust_rcu_assign_pointer(elem->probes, (*entry)->probes); CMM_STORE_SHARED(elem->state, active); } @@ -399,7 +378,7 @@ static void set_tracepoint(struct tracepoint_entry **entry, static void disable_tracepoint(struct lttng_ust_tracepoint *elem) { CMM_STORE_SHARED(elem->state, 0); - rcu_assign_pointer(elem->probes, NULL); + lttng_ust_rcu_assign_pointer(elem->probes, NULL); } /* @@ -415,9 +394,9 @@ static void add_callsite(struct tracepoint_lib * lib, struct lttng_ust_tracepoin uint32_t hash; struct tracepoint_entry *tp_entry; - if (name_len > LTTNG_UST_SYM_NAME_LEN - 1) { - WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_SYM_NAME_LEN - 1); - name_len = LTTNG_UST_SYM_NAME_LEN - 1; + if (name_len > LTTNG_UST_ABI_SYM_NAME_LEN - 1) { + WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_ABI_SYM_NAME_LEN - 1); + name_len = LTTNG_UST_ABI_SYM_NAME_LEN - 1; } hash = jhash(name, name_len, 0); head = &callsite_table[hash & (CALLSITE_TABLE_SIZE - 1)]; @@ -472,16 +451,16 @@ static void tracepoint_sync_callsites(const char *name) struct tracepoint_entry *tp_entry; tp_entry = get_tracepoint(name); - if (name_len > LTTNG_UST_SYM_NAME_LEN - 1) { - WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_SYM_NAME_LEN - 1); - name_len = LTTNG_UST_SYM_NAME_LEN - 1; + if (name_len > LTTNG_UST_ABI_SYM_NAME_LEN - 1) { + WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_ABI_SYM_NAME_LEN - 1); + name_len = LTTNG_UST_ABI_SYM_NAME_LEN - 1; } hash = jhash(name, name_len, 0); head = &callsite_table[hash & (CALLSITE_TABLE_SIZE - 1)]; cds_hlist_for_each_entry(e, node, head, hlist) { struct lttng_ust_tracepoint *tp = e->tp; - if (strncmp(name, tp->name, LTTNG_UST_SYM_NAME_LEN - 1)) + if (strncmp(name, tp->name, LTTNG_UST_ABI_SYM_NAME_LEN - 1)) continue; if (tp_entry) { if (!e->tp_entry_callsite_ref) { @@ -640,10 +619,10 @@ end: /* * Caller needs to invoke __tracepoint_probe_release_queue() after - * calling __tracepoint_probe_register_queue_release() one or multiple + * calling lttng_ust_tp_probe_register_queue_release() one or multiple * times to ensure it does not leak memory. */ -int __tracepoint_probe_register_queue_release(const char *name, +int lttng_ust_tp_probe_register_queue_release(const char *name, void (*probe)(void), void *data, const char *signature) { void *old; @@ -711,10 +690,10 @@ end: /* * Caller needs to invoke __tracepoint_probe_release_queue() after - * calling __tracepoint_probe_unregister_queue_release() one or multiple + * calling lttng_ust_tp_probe_unregister_queue_release() one or multiple * times to ensure it does not leak memory. */ -int __tracepoint_probe_unregister_queue_release(const char *name, +int lttng_ust_tp_probe_unregister_queue_release(const char *name, void (*probe)(void), void *data) { void *old; @@ -735,7 +714,7 @@ end: return ret; } -void __tracepoint_probe_prune_release_queue(void) +void lttng_ust_tp_probe_prune_release_queue(void) { CDS_LIST_HEAD(release_probes); struct tp_probes *pos, *next; @@ -750,7 +729,7 @@ void __tracepoint_probe_prune_release_queue(void) release_queue_need_update = 0; /* Wait for grace period between all sync_callsites and free. */ - urcu_bp_synchronize_rcu(); + lttng_ust_urcu_synchronize_rcu(); cds_list_for_each_entry_safe(pos, next, &release_probes, u.list) { cds_list_del(&pos->u.list); @@ -841,7 +820,7 @@ void tracepoint_probe_update_all(void) tracepoint_update_probes(); /* Wait for grace period between update_probes and free. */ - urcu_bp_synchronize_rcu(); + lttng_ust_urcu_synchronize_rcu(); cds_list_for_each_entry_safe(pos, next, &release_probes, u.list) { cds_list_del(&pos->u.list); free(pos); @@ -868,12 +847,24 @@ static void new_tracepoints(struct lttng_ust_tracepoint * const *start, } } +/* + * tracepoint_{un,}register_lib is meant to be looked up by instrumented + * applications through dlsym(). If found, those can register their + * tracepoints, else those tracepoints will not be available for + * tracing. The number at the end of those symbols acts as a major + * version for tracepoints. + * + * Older instrumented applications should still work with newer + * liblttng-ust, but it is fine that instrumented applications compiled + * against recent liblttng-ust headers require a recent liblttng-ust + * runtime for those tracepoints to be taken into account. + */ int tracepoint_register_lib(struct lttng_ust_tracepoint * const *tracepoints_start, - int tracepoints_count) + int tracepoints_count) { struct tracepoint_lib *pl, *iter; - init_tracepoint(); + lttng_ust_tp_init(); pl = (struct tracepoint_lib *) zmalloc(sizeof(struct tracepoint_lib)); if (!pl) { @@ -906,7 +897,7 @@ lib_added: DBG("just registered a tracepoints section from %p and having %d tracepoints", tracepoints_start, tracepoints_count); - if (ust_debug()) { + if (ust_err_debug_enabled()) { int i; for (i = 0; i < tracepoints_count; i++) { @@ -965,15 +956,15 @@ static void check_weak_hidden(void) "DIFFERENT addresses"); } -void init_tracepoint(void) +void lttng_ust_tp_init(void) { if (uatomic_xchg(&initialized, 1) == 1) return; - init_usterr(); + ust_err_init(); check_weak_hidden(); } -void exit_tracepoint(void) +void lttng_ust_tp_exit(void) { initialized = 0; } @@ -981,23 +972,23 @@ void exit_tracepoint(void) /* * Create the wrapper symbols. */ -#undef tp_rcu_read_lock_bp -#undef tp_rcu_read_unlock_bp -#undef tp_rcu_dereference_bp +#undef tp_rcu_read_lock +#undef tp_rcu_read_unlock +#undef tp_rcu_dereference -void tp_rcu_read_lock_bp(void) +void tp_rcu_read_lock(void) { - urcu_bp_read_lock(); + lttng_ust_urcu_read_lock(); } -void tp_rcu_read_unlock_bp(void) +void tp_rcu_read_unlock(void) { - urcu_bp_read_unlock(); + lttng_ust_urcu_read_unlock(); } -void *tp_rcu_dereference_sym_bp(void *p) +void *tp_rcu_dereference_sym(void *p) { - return urcu_bp_dereference(p); + return lttng_ust_rcu_dereference(p); } /*