| 1 | /* |
| 2 | * SPDX-License-Identifier: LGPL-2.1-only |
| 3 | * |
| 4 | * Copyright (C) 2013 Paul Woegerer <paul.woegerer@mentor.com> |
| 5 | * Copyright (C) 2015 Antoine Busque <abusque@efficios.com> |
| 6 | * Copyright (C) 2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 7 | */ |
| 8 | |
| 9 | #define _LGPL_SOURCE |
| 10 | |
| 11 | /* Has to be included first to override dlfcn.h */ |
| 12 | #include <common/compat/dlfcn.h> |
| 13 | |
| 14 | #include <limits.h> |
| 15 | #include <stdio.h> |
| 16 | #include <stdint.h> |
| 17 | #include <sys/types.h> |
| 18 | #include <unistd.h> |
| 19 | |
| 20 | #include "common/elf.h" |
| 21 | #include <lttng/ust-events.h> |
| 22 | #include "common/macros.h" |
| 23 | #include "common/logging.h" |
| 24 | |
| 25 | #include "../liblttng-ust/ust-events-internal.h" |
| 26 | |
| 27 | /* Include link.h last else it conflicts with ust-dlfcn. */ |
| 28 | #include <link.h> |
| 29 | |
| 30 | #define TRACEPOINT_DEFINE |
| 31 | #include "ust_dl.h" |
| 32 | |
| 33 | static void *(*__lttng_ust_plibc_dlopen)(const char *filename, int flags); |
| 34 | #ifdef HAVE_DLMOPEN |
| 35 | static void *(*__lttng_ust_plibc_dlmopen)(Lmid_t nsid, const char *filename, |
| 36 | int flags); |
| 37 | #endif |
| 38 | static int (*__lttng_ust_plibc_dlclose)(void *handle); |
| 39 | |
| 40 | static |
| 41 | void _lttng_ust_dl_init(void) |
| 42 | __attribute__((constructor)); |
| 43 | static |
| 44 | void _lttng_ust_dl_init(void) |
| 45 | { |
| 46 | ust_err_init(); |
| 47 | } |
| 48 | |
| 49 | static |
| 50 | void *_lttng_ust_dl_libc_dlopen(const char *filename, int flags) |
| 51 | { |
| 52 | if (!__lttng_ust_plibc_dlopen) { |
| 53 | __lttng_ust_plibc_dlopen = dlsym(RTLD_NEXT, "dlopen"); |
| 54 | if (!__lttng_ust_plibc_dlopen) { |
| 55 | fprintf(stderr, "%s\n", dlerror()); |
| 56 | return NULL; |
| 57 | } |
| 58 | } |
| 59 | return __lttng_ust_plibc_dlopen(filename, flags); |
| 60 | } |
| 61 | |
| 62 | #ifdef HAVE_DLMOPEN |
| 63 | static |
| 64 | void *_lttng_ust_dl_libc_dlmopen(Lmid_t nsid, const char *filename, |
| 65 | int flags) |
| 66 | { |
| 67 | if (!__lttng_ust_plibc_dlmopen) { |
| 68 | __lttng_ust_plibc_dlmopen = dlsym(RTLD_NEXT, "dlmopen"); |
| 69 | if (!__lttng_ust_plibc_dlmopen) { |
| 70 | fprintf(stderr, "%s\n", dlerror()); |
| 71 | return NULL; |
| 72 | } |
| 73 | } |
| 74 | return __lttng_ust_plibc_dlmopen(nsid, filename, flags); |
| 75 | } |
| 76 | #endif |
| 77 | |
| 78 | static |
| 79 | int _lttng_ust_dl_libc_dlclose(void *handle) |
| 80 | { |
| 81 | if (!__lttng_ust_plibc_dlclose) { |
| 82 | __lttng_ust_plibc_dlclose = dlsym(RTLD_NEXT, "dlclose"); |
| 83 | if (!__lttng_ust_plibc_dlclose) { |
| 84 | fprintf(stderr, "%s\n", dlerror()); |
| 85 | return -1; |
| 86 | } |
| 87 | } |
| 88 | return __lttng_ust_plibc_dlclose(handle); |
| 89 | } |
| 90 | |
| 91 | static |
| 92 | void lttng_ust_dl_dlopen(void *so_base, const char *so_name, |
| 93 | int flags, void *ip) |
| 94 | { |
| 95 | char resolved_path[PATH_MAX]; |
| 96 | struct lttng_ust_elf *elf; |
| 97 | uint64_t memsz; |
| 98 | uint8_t *build_id = NULL; |
| 99 | size_t build_id_len; |
| 100 | char *dbg_file = NULL; |
| 101 | uint32_t crc; |
| 102 | int has_build_id = 0, has_debug_link = 0; |
| 103 | int ret; |
| 104 | |
| 105 | if (!realpath(so_name, resolved_path)) { |
| 106 | ERR("could not resolve path '%s'", so_name); |
| 107 | return; |
| 108 | } |
| 109 | |
| 110 | elf = lttng_ust_elf_create(resolved_path); |
| 111 | if (!elf) { |
| 112 | ERR("could not access file %s", resolved_path); |
| 113 | return; |
| 114 | } |
| 115 | |
| 116 | ret = lttng_ust_elf_get_memsz(elf, &memsz); |
| 117 | if (ret) { |
| 118 | goto end; |
| 119 | } |
| 120 | ret = lttng_ust_elf_get_build_id( |
| 121 | elf, &build_id, &build_id_len, &has_build_id); |
| 122 | if (ret) { |
| 123 | goto end; |
| 124 | } |
| 125 | ret = lttng_ust_elf_get_debug_link( |
| 126 | elf, &dbg_file, &crc, &has_debug_link); |
| 127 | if (ret) { |
| 128 | goto end; |
| 129 | } |
| 130 | |
| 131 | tracepoint(lttng_ust_dl, dlopen, |
| 132 | ip, so_base, resolved_path, flags, memsz, |
| 133 | has_build_id, has_debug_link); |
| 134 | |
| 135 | if (has_build_id) { |
| 136 | tracepoint(lttng_ust_dl, build_id, |
| 137 | ip, so_base, build_id, build_id_len); |
| 138 | } |
| 139 | |
| 140 | if (has_debug_link) { |
| 141 | tracepoint(lttng_ust_dl, debug_link, |
| 142 | ip, so_base, dbg_file, crc); |
| 143 | } |
| 144 | |
| 145 | end: |
| 146 | free(dbg_file); |
| 147 | free(build_id); |
| 148 | lttng_ust_elf_destroy(elf); |
| 149 | return; |
| 150 | } |
| 151 | |
| 152 | #ifdef HAVE_DLMOPEN |
| 153 | static |
| 154 | void lttng_ust_dl_dlmopen(void *so_base, Lmid_t nsid, const char *so_name, |
| 155 | int flags, void *ip) |
| 156 | { |
| 157 | char resolved_path[PATH_MAX]; |
| 158 | struct lttng_ust_elf *elf; |
| 159 | uint64_t memsz; |
| 160 | uint8_t *build_id = NULL; |
| 161 | size_t build_id_len; |
| 162 | char *dbg_file = NULL; |
| 163 | uint32_t crc; |
| 164 | int has_build_id = 0, has_debug_link = 0; |
| 165 | int ret; |
| 166 | |
| 167 | if (!realpath(so_name, resolved_path)) { |
| 168 | ERR("could not resolve path '%s'", so_name); |
| 169 | return; |
| 170 | } |
| 171 | |
| 172 | elf = lttng_ust_elf_create(resolved_path); |
| 173 | if (!elf) { |
| 174 | ERR("could not access file %s", resolved_path); |
| 175 | return; |
| 176 | } |
| 177 | |
| 178 | ret = lttng_ust_elf_get_memsz(elf, &memsz); |
| 179 | if (ret) { |
| 180 | goto end; |
| 181 | } |
| 182 | ret = lttng_ust_elf_get_build_id( |
| 183 | elf, &build_id, &build_id_len, &has_build_id); |
| 184 | if (ret) { |
| 185 | goto end; |
| 186 | } |
| 187 | ret = lttng_ust_elf_get_debug_link( |
| 188 | elf, &dbg_file, &crc, &has_debug_link); |
| 189 | if (ret) { |
| 190 | goto end; |
| 191 | } |
| 192 | |
| 193 | tracepoint(lttng_ust_dl, dlmopen, |
| 194 | ip, so_base, nsid, resolved_path, flags, memsz, |
| 195 | has_build_id, has_debug_link); |
| 196 | |
| 197 | if (has_build_id) { |
| 198 | tracepoint(lttng_ust_dl, build_id, |
| 199 | ip, so_base, build_id, build_id_len); |
| 200 | } |
| 201 | |
| 202 | if (has_debug_link) { |
| 203 | tracepoint(lttng_ust_dl, debug_link, |
| 204 | ip, so_base, dbg_file, crc); |
| 205 | } |
| 206 | |
| 207 | end: |
| 208 | free(dbg_file); |
| 209 | free(build_id); |
| 210 | lttng_ust_elf_destroy(elf); |
| 211 | return; |
| 212 | } |
| 213 | #endif |
| 214 | |
| 215 | void *dlopen(const char *filename, int flags) |
| 216 | { |
| 217 | void *handle; |
| 218 | |
| 219 | handle = _lttng_ust_dl_libc_dlopen(filename, flags); |
| 220 | if (__tracepoint_ptrs_registered && handle) { |
| 221 | struct link_map *p = NULL; |
| 222 | int ret; |
| 223 | |
| 224 | ret = dlinfo(handle, RTLD_DI_LINKMAP, &p); |
| 225 | if (ret != -1 && p != NULL && p->l_addr != 0) { |
| 226 | lttng_ust_dl_dlopen((void *) p->l_addr, |
| 227 | p->l_name, flags, LTTNG_UST_CALLER_IP()); |
| 228 | } |
| 229 | } |
| 230 | lttng_ust_dl_update(LTTNG_UST_CALLER_IP()); |
| 231 | return handle; |
| 232 | } |
| 233 | |
| 234 | #ifdef HAVE_DLMOPEN |
| 235 | void *dlmopen(Lmid_t nsid, const char *filename, int flags) |
| 236 | { |
| 237 | void *handle; |
| 238 | |
| 239 | handle = _lttng_ust_dl_libc_dlmopen(nsid, filename, flags); |
| 240 | if (__tracepoint_ptrs_registered && handle) { |
| 241 | struct link_map *p = NULL; |
| 242 | int ret; |
| 243 | |
| 244 | ret = dlinfo(handle, RTLD_DI_LINKMAP, &p); |
| 245 | if (ret != -1 && p != NULL && p->l_addr != 0) { |
| 246 | lttng_ust_dl_dlmopen((void *) p->l_addr, |
| 247 | nsid, p->l_name, flags, |
| 248 | LTTNG_UST_CALLER_IP()); |
| 249 | } |
| 250 | } |
| 251 | lttng_ust_dl_update(LTTNG_UST_CALLER_IP()); |
| 252 | return handle; |
| 253 | |
| 254 | } |
| 255 | #endif |
| 256 | |
| 257 | int dlclose(void *handle) |
| 258 | { |
| 259 | int ret; |
| 260 | |
| 261 | if (__tracepoint_ptrs_registered) { |
| 262 | struct link_map *p = NULL; |
| 263 | |
| 264 | ret = dlinfo(handle, RTLD_DI_LINKMAP, &p); |
| 265 | if (ret != -1 && p != NULL && p->l_addr != 0) { |
| 266 | tracepoint(lttng_ust_dl, dlclose, |
| 267 | LTTNG_UST_CALLER_IP(), |
| 268 | (void *) p->l_addr); |
| 269 | } |
| 270 | } |
| 271 | ret = _lttng_ust_dl_libc_dlclose(handle); |
| 272 | lttng_ust_dl_update(LTTNG_UST_CALLER_IP()); |
| 273 | return ret; |
| 274 | } |