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