From 97c7c238f60194565d4839e38e712414c22494e3 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 4 Jul 2016 15:39:01 -0400 Subject: [PATCH] Add library load/unload tracking events Track library load and unload, with the following new events: lttng_ust_lib:load lttng_ust_lib:build_id lttng_ust_lib:debug_link lttng_ust_lib:unload This takes care of correctly tracing the mapping of direct dependencies of dlopen'd libraries, which was not appropriately done by tracing just dlopen events. Fixes: #1035 Signed-off-by: Mathieu Desnoyers --- include/lttng/ust-events.h | 2 + liblttng-ust-dl/lttng-ust-dl.c | 15 +- liblttng-ust/Makefile.am | 2 + liblttng-ust/lttng-ust-elf.c | 1 + liblttng-ust/lttng-ust-statedump.c | 395 ++++++++++++++++++++++++----- 5 files changed, 350 insertions(+), 65 deletions(-) diff --git a/include/lttng/ust-events.h b/include/lttng/ust-events.h index 039b2ccb..5167ddee 100644 --- a/include/lttng/ust-events.h +++ b/include/lttng/ust-events.h @@ -723,6 +723,8 @@ struct cds_list_head *_lttng_get_sessions(void); struct lttng_enum *lttng_ust_enum_get(struct lttng_session *session, const char *enum_name); +void lttng_ust_dl_update(void *ip); + /* For backward compatibility. Leave those exported symbols in place. */ extern struct lttng_ctx *lttng_static_ctx; void lttng_context_init(void); diff --git a/liblttng-ust-dl/lttng-ust-dl.c b/liblttng-ust-dl/lttng-ust-dl.c index e457e7a3..81b5bec4 100644 --- a/liblttng-ust-dl/lttng-ust-dl.c +++ b/liblttng-ust-dl/lttng-ust-dl.c @@ -1,6 +1,7 @@ /* * Copyright (C) 2013 Paul Woegerer * Copyright (C) 2015 Antoine Busque + * Copyright (C) 2016 Mathieu Desnoyers * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -26,6 +27,7 @@ #include #include +#include #include #include "usterr-signal-safe.h" @@ -135,19 +137,21 @@ void *dlopen(const char *filename, int flag) ret = dlinfo(handle, RTLD_DI_LINKMAP, &p); if (ret != -1 && p != NULL && p->l_addr != 0) { - lttng_ust_dl_dlopen((void *) p->l_addr, p->l_name, + lttng_ust_dl_dlopen((void *) p->l_addr, + p->l_name, LTTNG_UST_CALLER_IP()); } } - + lttng_ust_dl_update(LTTNG_UST_CALLER_IP()); return handle; } int dlclose(void *handle) { + int ret; + if (__tracepoint_ptrs_registered) { struct link_map *p = NULL; - int ret; ret = dlinfo(handle, RTLD_DI_LINKMAP, &p); if (ret != -1 && p != NULL && p->l_addr != 0) { @@ -156,6 +160,7 @@ int dlclose(void *handle) (void *) p->l_addr); } } - - return _lttng_ust_dl_libc_dlclose(handle); + ret = _lttng_ust_dl_libc_dlclose(handle); + lttng_ust_dl_update(LTTNG_UST_CALLER_IP()); + return ret; } diff --git a/liblttng-ust/Makefile.am b/liblttng-ust/Makefile.am index 05929be7..a2a32b4e 100644 --- a/liblttng-ust/Makefile.am +++ b/liblttng-ust/Makefile.am @@ -43,6 +43,8 @@ liblttng_ust_runtime_la_SOURCES = \ lttng-ust-statedump.c \ lttng-ust-statedump.h \ lttng-ust-statedump-provider.h \ + ust_lib.c \ + ust_lib.h \ tracepoint-internal.h \ clock.h \ compat.h \ diff --git a/liblttng-ust/lttng-ust-elf.c b/liblttng-ust/lttng-ust-elf.c index 5f27920e..e5b8a08f 100644 --- a/liblttng-ust/lttng-ust-elf.c +++ b/liblttng-ust/lttng-ust-elf.c @@ -25,6 +25,7 @@ #include #include #include +#include #include "lttng-tracer-core.h" #define BUF_LEN 4096 diff --git a/liblttng-ust/lttng-ust-statedump.c b/liblttng-ust/lttng-ust-statedump.c index bcb168be..c8e508cd 100644 --- a/liblttng-ust/lttng-ust-statedump.c +++ b/liblttng-ust/lttng-ust-statedump.c @@ -1,6 +1,7 @@ /* * Copyright (C) 2013 Paul Woegerer * Copyright (C) 2015 Antoine Busque + * Copyright (C) 2016 Mathieu Desnoyers * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -24,27 +25,32 @@ #include #include #include +#include #include #include #include +#include #include "lttng-tracer-core.h" #include "lttng-ust-statedump.h" +#include "jhash.h" #define TRACEPOINT_DEFINE +#include "ust_lib.h" /* Only define. */ + #define TRACEPOINT_CREATE_PROBES #define TP_SESSION_CHECK -#include "lttng-ust-statedump-provider.h" +#include "lttng-ust-statedump-provider.h" /* Define and create probes. */ struct dl_iterate_data { - void *owner; int exec_found; + bool first; + bool cancel; }; struct bin_info_data { - void *owner; void *base_addr_ptr; - const char *resolved_path; + char resolved_path[PATH_MAX]; char *dbg_file; uint8_t *build_id; uint64_t memsz; @@ -56,14 +62,143 @@ struct bin_info_data { uint8_t has_debug_link; }; +struct lttng_ust_dl_node { + struct bin_info_data bin_data; + struct cds_hlist_node node; + bool traced; + bool marked; +}; + +#define UST_DL_STATE_HASH_BITS 8 +#define UST_DL_STATE_TABLE_SIZE (1 << UST_DL_STATE_HASH_BITS) +struct cds_hlist_head dl_state_table[UST_DL_STATE_TABLE_SIZE]; + typedef void (*tracepoint_cb)(struct lttng_session *session, void *priv); +static +struct lttng_ust_dl_node *alloc_dl_node(const struct bin_info_data *bin_data) +{ + struct lttng_ust_dl_node *e; + + e = zmalloc(sizeof(struct lttng_ust_dl_node)); + if (!e) + return NULL; + if (bin_data->dbg_file) { + e->bin_data.dbg_file = strdup(bin_data->dbg_file); + if (!e->bin_data.dbg_file) + goto error; + } + if (bin_data->build_id) { + e->bin_data.build_id = zmalloc(bin_data->build_id_len); + if (!e->bin_data.build_id) + goto error; + memcpy(e->bin_data.build_id, bin_data->build_id, + bin_data->build_id_len); + } + e->bin_data.base_addr_ptr = bin_data->base_addr_ptr; + memcpy(e->bin_data.resolved_path, bin_data->resolved_path, PATH_MAX); + e->bin_data.memsz = bin_data->memsz; + e->bin_data.build_id_len = bin_data->build_id_len; + e->bin_data.vdso = bin_data->vdso; + e->bin_data.crc = bin_data->crc; + e->bin_data.is_pic = bin_data->is_pic; + e->bin_data.has_build_id = bin_data->has_build_id; + e->bin_data.has_debug_link = bin_data->has_debug_link; + return e; + +error: + free(e->bin_data.build_id); + free(e->bin_data.dbg_file); + free(e); + return NULL; +} + +static +void free_dl_node(struct lttng_ust_dl_node *e) +{ + free(e->bin_data.build_id); + free(e->bin_data.dbg_file); + free(e); +} + +/* Return 0 if same, nonzero if not. */ +static +int compare_bin_data(const struct bin_info_data *a, + const struct bin_info_data *b) +{ + if (a->base_addr_ptr != b->base_addr_ptr) + return -1; + if (strcmp(a->resolved_path, b->resolved_path) != 0) + return -1; + if (a->dbg_file && !b->dbg_file) + return -1; + if (!a->dbg_file && b->dbg_file) + return -1; + if (a->dbg_file && strcmp(a->dbg_file, b->dbg_file) != 0) + return -1; + if (a->build_id && !b->build_id) + return -1; + if (!a->build_id && b->build_id) + return -1; + if (a->build_id_len != b->build_id_len) + return -1; + if (a->build_id && + memcmp(a->build_id, b->build_id, a->build_id_len) != 0) + return -1; + if (a->memsz != b->memsz) + return -1; + if (a->vdso != b->vdso) + return -1; + if (a->crc != b->crc) + return -1; + if (a->is_pic != b->is_pic) + return -1; + if (a->has_build_id != b->has_build_id) + return -1; + if (a->has_debug_link != b->has_debug_link) + return -1; + return 0; +} + +static +struct lttng_ust_dl_node *find_or_create_dl_node(struct bin_info_data *bin_data) +{ + struct cds_hlist_head *head; + struct lttng_ust_dl_node *e; + unsigned int hash; + bool found = false; + + hash = jhash(&bin_data->base_addr_ptr, + sizeof(bin_data->base_addr_ptr), 0); + head = &dl_state_table[hash & (UST_DL_STATE_TABLE_SIZE - 1)]; + cds_hlist_for_each_entry_2(e, head, node) { + if (compare_bin_data(&e->bin_data, bin_data) != 0) + continue; + found = true; + break; + } + if (!found) { + /* Create */ + e = alloc_dl_node(bin_data); + if (!e) + return NULL; + cds_hlist_add_head(&e->node, head); + } + return e; +} + +static +void remove_dl_node(struct lttng_ust_dl_node *e) +{ + cds_hlist_del(&e->node); +} + /* * Trace statedump event into all sessions owned by the caller thread * for which statedump is pending. */ static -int trace_statedump_event(tracepoint_cb tp_cb, void *owner, void *priv) +void trace_statedump_event(tracepoint_cb tp_cb, void *owner, void *priv) { struct cds_list_head *sessionsp; struct lttng_session *session; @@ -76,7 +211,6 @@ int trace_statedump_event(tracepoint_cb tp_cb, void *owner, void *priv) continue; tp_cb(session, priv); } - return 0; } static @@ -165,9 +299,22 @@ end: } static -int trace_baddr(struct bin_info_data *bin_data) +void trace_baddr(struct bin_info_data *bin_data, void *owner) +{ + trace_statedump_event(trace_bin_info_cb, owner, bin_data); + + if (bin_data->has_build_id) + trace_statedump_event(trace_build_id_cb, owner, bin_data); + + if (bin_data->has_debug_link) + trace_statedump_event(trace_debug_link_cb, owner, bin_data); +} + +static +int extract_baddr(struct bin_info_data *bin_data) { int ret = 0; + struct lttng_ust_dl_node *e; if (!bin_data->vdso) { ret = get_elf_info(bin_data); @@ -180,73 +327,146 @@ int trace_baddr(struct bin_info_data *bin_data) bin_data->has_debug_link = 0; } - ret = trace_statedump_event(trace_bin_info_cb, bin_data->owner, - bin_data); - if (ret) { + e = find_or_create_dl_node(bin_data); + if (!e) { + ret = -1; goto end; } - - if (bin_data->has_build_id) { - ret = trace_statedump_event( - trace_build_id_cb, bin_data->owner, bin_data); - free(bin_data->build_id); - if (ret) { - goto end; - } - } - - if (bin_data->has_debug_link) { - ret = trace_statedump_event( - trace_debug_link_cb, bin_data->owner, bin_data); - free(bin_data->dbg_file); - if (ret) { - goto end; - } - } - + e->marked = true; end: + free(bin_data->build_id); + bin_data->build_id = NULL; + free(bin_data->dbg_file); + bin_data->dbg_file = NULL; return ret; } static -int trace_statedump_start(void *owner) +void trace_statedump_start(void *owner) { - return trace_statedump_event(trace_start_cb, owner, NULL); + trace_statedump_event(trace_start_cb, owner, NULL); } static -int trace_statedump_end(void *owner) +void trace_statedump_end(void *owner) { - return trace_statedump_event(trace_end_cb, owner, NULL); + trace_statedump_event(trace_end_cb, owner, NULL); } static -int extract_bin_info_events(struct dl_phdr_info *info, size_t size, void *_data) +void iter_begin(struct dl_iterate_data *data) { - int j, ret = 0; - struct dl_iterate_data *data = _data; + unsigned int i; /* * UST lock nests within dynamic loader lock. * - * Hold this lock across handling of the entire module to + * Hold this lock across handling of the module listing to * protect memory allocation at early process start, due to * interactions with libc-wrapper lttng malloc instrumentation. */ if (ust_lock()) { - goto end; + data->cancel = true; + return; } + /* Ensure all entries are unmarked. */ + for (i = 0; i < UST_DL_STATE_TABLE_SIZE; i++) { + struct cds_hlist_head *head; + struct lttng_ust_dl_node *e; + + head = &dl_state_table[i]; + cds_hlist_for_each_entry_2(e, head, node) + assert(!e->marked); + } +} + +static +void trace_lib_load(const struct bin_info_data *bin_data, void *ip) +{ + tracepoint(lttng_ust_lib, load, + ip, bin_data->base_addr_ptr, bin_data->resolved_path, + bin_data->memsz, bin_data->has_build_id, + bin_data->has_debug_link); + + if (bin_data->has_build_id) { + tracepoint(lttng_ust_lib, build_id, + ip, bin_data->base_addr_ptr, bin_data->build_id, + bin_data->build_id_len); + } + + if (bin_data->has_debug_link) { + tracepoint(lttng_ust_lib, debug_link, + ip, bin_data->base_addr_ptr, bin_data->dbg_file, + bin_data->crc); + } +} + +static +void trace_lib_unload(const struct bin_info_data *bin_data, void *ip) +{ + tracepoint(lttng_ust_lib, unload, ip, bin_data->base_addr_ptr); +} + +static +void iter_end(struct dl_iterate_data *data, void *ip) +{ + unsigned int i; + + /* + * Iterate on hash table. + * For each marked, traced, do nothing. + * For each marked, not traced, trace lib open event. traced = true. + * For each unmarked, traced, trace lib close event. remove node. + * For each unmarked, not traced, remove node. + */ + for (i = 0; i < UST_DL_STATE_TABLE_SIZE; i++) { + struct cds_hlist_head *head; + struct lttng_ust_dl_node *e; + + head = &dl_state_table[i]; + cds_hlist_for_each_entry_2(e, head, node) { + if (e->marked) { + if (!e->traced) { + trace_lib_load(&e->bin_data, ip); + e->traced = true; + } + } else { + if (e->traced) + trace_lib_unload(&e->bin_data, ip); + remove_dl_node(e); + free_dl_node(e); + } + e->marked = false; + } + } + ust_unlock(); +} + +static +int extract_bin_info_events(struct dl_phdr_info *info, size_t size, void *_data) +{ + int j, ret = 0; + struct dl_iterate_data *data = _data; + + if (data->first) { + iter_begin(data); + data->first = false; + } + + if (data->cancel) + goto end; + for (j = 0; j < info->dlpi_phnum; j++) { struct bin_info_data bin_data; - char resolved_path[PATH_MAX]; - void *base_addr_ptr; if (info->dlpi_phdr[j].p_type != PT_LOAD) continue; + memset(&bin_data, 0, sizeof(bin_data)); + /* Calculate virtual memory address of the loadable segment */ - base_addr_ptr = (void *) info->dlpi_addr + + bin_data.base_addr_ptr = (void *) info->dlpi_addr + info->dlpi_phdr[j].p_vaddr; if ((info->dlpi_name == NULL || info->dlpi_name[0] == 0)) { @@ -264,15 +484,16 @@ int extract_bin_info_events(struct dl_phdr_info *info, size_t size, void *_data) * executable's full path. */ path_len = readlink("/proc/self/exe", - resolved_path, + bin_data.resolved_path, PATH_MAX - 1); if (path_len <= 0) break; - resolved_path[path_len] = '\0'; + bin_data.resolved_path[path_len] = '\0'; bin_data.vdso = 0; } else { - snprintf(resolved_path, PATH_MAX - 1, "[vdso]"); + snprintf(bin_data.resolved_path, + PATH_MAX - 1, "[vdso]"); bin_data.vdso = 1; } } else { @@ -281,8 +502,10 @@ int extract_bin_info_events(struct dl_phdr_info *info, size_t size, void *_data) * the path to the binary really exists. If not, * treat as vdso and use dlpi_name as 'path'. */ - if (!realpath(info->dlpi_name, resolved_path)) { - snprintf(resolved_path, PATH_MAX - 1, "[%s]", + if (!realpath(info->dlpi_name, + bin_data.resolved_path)) { + snprintf(bin_data.resolved_path, + PATH_MAX - 1, "[%s]", info->dlpi_name); bin_data.vdso = 1; } else { @@ -290,39 +513,73 @@ int extract_bin_info_events(struct dl_phdr_info *info, size_t size, void *_data) } } - bin_data.owner = data->owner; - bin_data.base_addr_ptr = base_addr_ptr; - bin_data.resolved_path = resolved_path; - ret = trace_baddr(&bin_data); + ret = extract_baddr(&bin_data); break; } end: - ust_unlock(); return ret; } -/* - * Generate a statedump of base addresses of all shared objects loaded - * by the traced application, as well as for the application's - * executable itself. - */ static -int do_baddr_statedump(void *owner) +void ust_dl_table_statedump(void *owner) +{ + unsigned int i; + + if (ust_lock()) + goto end; + + /* Statedump each traced table entry into session for owner. */ + for (i = 0; i < UST_DL_STATE_TABLE_SIZE; i++) { + struct cds_hlist_head *head; + struct lttng_ust_dl_node *e; + + head = &dl_state_table[i]; + cds_hlist_for_each_entry_2(e, head, node) { + if (e->traced) + trace_baddr(&e->bin_data, owner); + } + } + +end: + ust_unlock(); +} + +void lttng_ust_dl_update(void *ip) { struct dl_iterate_data data; if (getenv("LTTNG_UST_WITHOUT_BADDR_STATEDUMP")) - return 0; + return; - data.owner = owner; data.exec_found = 0; + data.first = true; + data.cancel = false; /* * Iterate through the list of currently loaded shared objects and - * generate events for loadable segments using + * generate tables entries for loadable segments using * extract_bin_info_events. + * Removed libraries are detected by mark-and-sweep: marking is + * done in the iteration over libraries, and sweeping is + * performed by iter_end(). */ dl_iterate_phdr(extract_bin_info_events, &data); + if (data.first) + iter_begin(&data); + iter_end(&data, ip); +} +/* + * Generate a statedump of base addresses of all shared objects loaded + * by the traced application, as well as for the application's + * executable itself. + */ +static +int do_baddr_statedump(void *owner) +{ + if (getenv("LTTNG_UST_WITHOUT_BADDR_STATEDUMP")) + return 0; + lttng_ust_dl_update(LTTNG_UST_CALLER_IP()); + ust_dl_table_statedump(owner); return 0; } @@ -348,6 +605,23 @@ void lttng_ust_statedump_init(void) __tracepoints__init(); __tracepoints__ptrs_init(); __lttng_events_init__lttng_ust_statedump(); + lttng_ust_dl_update(LTTNG_UST_CALLER_IP()); +} + +static +void ust_dl_state_destroy(void) +{ + unsigned int i; + + for (i = 0; i < UST_DL_STATE_TABLE_SIZE; i++) { + struct cds_hlist_head *head; + struct lttng_ust_dl_node *e, *tmp; + + head = &dl_state_table[i]; + cds_hlist_for_each_entry_safe_2(e, tmp, head, node) + free_dl_node(e); + CDS_INIT_HLIST_HEAD(head); + } } void lttng_ust_statedump_destroy(void) @@ -355,4 +629,5 @@ void lttng_ust_statedump_destroy(void) __lttng_events_exit__lttng_ust_statedump(); __tracepoints__ptrs_destroy(); __tracepoints__destroy(); + ust_dl_state_destroy(); } -- 2.34.1