| 1 | /* |
| 2 | * Copyright (C) 2013 Paul Woegerer <paul.woegerer@mentor.com> |
| 3 | * Copyright (C) 2015 Antoine Busque <abusque@efficios.com> |
| 4 | * |
| 5 | * This library is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU Lesser General Public |
| 7 | * License as published by the Free Software Foundation; version 2.1 of |
| 8 | * the License. |
| 9 | * |
| 10 | * This library is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * Lesser General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU Lesser General Public |
| 16 | * License along with this library; if not, write to the Free Software |
| 17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 18 | */ |
| 19 | |
| 20 | #define _LGPL_SOURCE |
| 21 | #define _GNU_SOURCE |
| 22 | |
| 23 | #include <limits.h> |
| 24 | #include <stdio.h> |
| 25 | #include <sys/types.h> |
| 26 | #include <unistd.h> |
| 27 | |
| 28 | #include <lttng/ust-dlfcn.h> |
| 29 | #include <lttng/ust-elf.h> |
| 30 | #include "usterr-signal-safe.h" |
| 31 | |
| 32 | /* Include link.h last else it conflicts with ust-dlfcn. */ |
| 33 | #include <link.h> |
| 34 | |
| 35 | #define TRACEPOINT_DEFINE |
| 36 | #include "ust_dl.h" |
| 37 | |
| 38 | static void *(*__lttng_ust_plibc_dlopen)(const char *filename, int flag); |
| 39 | static int (*__lttng_ust_plibc_dlclose)(void *handle); |
| 40 | |
| 41 | static |
| 42 | void *_lttng_ust_dl_libc_dlopen(const char *filename, int flag) |
| 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, flag); |
| 52 | } |
| 53 | |
| 54 | static |
| 55 | int _lttng_ust_dl_libc_dlclose(void *handle) |
| 56 | { |
| 57 | if (!__lttng_ust_plibc_dlclose) { |
| 58 | __lttng_ust_plibc_dlclose = dlsym(RTLD_NEXT, "dlclose"); |
| 59 | if (!__lttng_ust_plibc_dlclose) { |
| 60 | fprintf(stderr, "%s\n", dlerror()); |
| 61 | return -1; |
| 62 | } |
| 63 | } |
| 64 | return __lttng_ust_plibc_dlclose(handle); |
| 65 | } |
| 66 | |
| 67 | static |
| 68 | void lttng_ust_dl_dlopen(void *so_base, const char *so_name, void *ip) |
| 69 | { |
| 70 | char resolved_path[PATH_MAX]; |
| 71 | struct lttng_ust_elf *elf; |
| 72 | uint64_t memsz; |
| 73 | uint8_t *build_id = NULL; |
| 74 | size_t build_id_len; |
| 75 | char *dbg_file = NULL; |
| 76 | uint32_t crc; |
| 77 | int has_build_id = 0, has_debug_link = 0; |
| 78 | int ret; |
| 79 | |
| 80 | if (!realpath(so_name, resolved_path)) { |
| 81 | ERR("could not resolve path '%s'", so_name); |
| 82 | return; |
| 83 | } |
| 84 | |
| 85 | elf = lttng_ust_elf_create(resolved_path); |
| 86 | if (!elf) { |
| 87 | ERR("could not acces file %s", resolved_path); |
| 88 | return; |
| 89 | } |
| 90 | |
| 91 | ret = lttng_ust_elf_get_memsz(elf, &memsz); |
| 92 | if (ret) { |
| 93 | goto end; |
| 94 | } |
| 95 | ret = lttng_ust_elf_get_build_id( |
| 96 | elf, &build_id, &build_id_len, &has_build_id); |
| 97 | if (ret) { |
| 98 | goto end; |
| 99 | } |
| 100 | ret = lttng_ust_elf_get_debug_link( |
| 101 | elf, &dbg_file, &crc, &has_debug_link); |
| 102 | if (ret) { |
| 103 | goto end; |
| 104 | } |
| 105 | |
| 106 | tracepoint(lttng_ust_dl, dlopen, |
| 107 | ip, so_base, resolved_path, memsz); |
| 108 | |
| 109 | if (has_build_id) { |
| 110 | tracepoint(lttng_ust_dl, build_id, |
| 111 | ip, so_base, build_id, build_id_len); |
| 112 | free(build_id); |
| 113 | } |
| 114 | |
| 115 | if (has_debug_link) { |
| 116 | tracepoint(lttng_ust_dl, debug_link, |
| 117 | ip, so_base, dbg_file, crc); |
| 118 | free(dbg_file); |
| 119 | } |
| 120 | |
| 121 | end: |
| 122 | free(dbg_file); |
| 123 | free(build_id); |
| 124 | lttng_ust_elf_destroy(elf); |
| 125 | return; |
| 126 | } |
| 127 | |
| 128 | void *dlopen(const char *filename, int flag) |
| 129 | { |
| 130 | void *handle; |
| 131 | |
| 132 | handle = _lttng_ust_dl_libc_dlopen(filename, flag); |
| 133 | if (__tracepoint_ptrs_registered && handle) { |
| 134 | struct link_map *p = NULL; |
| 135 | int ret; |
| 136 | |
| 137 | ret = dlinfo(handle, RTLD_DI_LINKMAP, &p); |
| 138 | if (ret != -1 && p != NULL && p->l_addr != 0) { |
| 139 | lttng_ust_dl_dlopen((void *) p->l_addr, p->l_name, |
| 140 | __builtin_return_address(0)); |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | return handle; |
| 145 | } |
| 146 | |
| 147 | int dlclose(void *handle) |
| 148 | { |
| 149 | if (__tracepoint_ptrs_registered && handle) { |
| 150 | struct link_map *p = NULL; |
| 151 | int ret; |
| 152 | |
| 153 | ret = dlinfo(handle, RTLD_DI_LINKMAP, &p); |
| 154 | if (ret != -1 && p != NULL && p->l_addr != 0) { |
| 155 | tracepoint(lttng_ust_dl, dlclose, |
| 156 | __builtin_return_address(0), |
| 157 | (void *) p->l_addr); |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | return _lttng_ust_dl_libc_dlclose(handle); |
| 162 | } |