| 1 | /* |
| 2 | * Copyright (C) 2013 Paul Woegerer <paul.woegerer@mentor.com> |
| 3 | * |
| 4 | * This library is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU Lesser General Public |
| 6 | * License as published by the Free Software Foundation; version 2.1 of |
| 7 | * the License. |
| 8 | * |
| 9 | * This library is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | * Lesser General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU Lesser General Public |
| 15 | * License along with this library; if not, write to the Free Software |
| 16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 17 | */ |
| 18 | |
| 19 | #define _GNU_SOURCE |
| 20 | #include <inttypes.h> |
| 21 | #include <dlfcn.h> |
| 22 | #include <link.h> |
| 23 | #include <unistd.h> |
| 24 | #include <stdio.h> |
| 25 | #include <signal.h> |
| 26 | #include <sched.h> |
| 27 | #include <stdarg.h> |
| 28 | #include "usterr.h" |
| 29 | |
| 30 | #include <lttng/ust-compiler.h> |
| 31 | #include <lttng/ust.h> |
| 32 | |
| 33 | static void *(*__lttng_ust_plibc_dlopen)(const char *filename, int flag); |
| 34 | static int (*__lttng_ust_plibc_dlclose)(void *handle); |
| 35 | static void *__lttng_ust_baddr_handle; |
| 36 | |
| 37 | static |
| 38 | void *_lttng_ust_dl_libc_dlopen(const char *filename, int flag) |
| 39 | { |
| 40 | if (!__lttng_ust_plibc_dlopen) { |
| 41 | __lttng_ust_plibc_dlopen = dlsym(RTLD_NEXT, "dlopen"); |
| 42 | if (__lttng_ust_plibc_dlopen == NULL) { |
| 43 | fprintf(stderr, "%s\n", dlerror()); |
| 44 | return NULL; |
| 45 | } |
| 46 | } |
| 47 | return __lttng_ust_plibc_dlopen(filename, flag); |
| 48 | } |
| 49 | |
| 50 | static |
| 51 | int _lttng_ust_dl_libc_dlclose(void *handle) |
| 52 | { |
| 53 | if (!__lttng_ust_plibc_dlclose) { |
| 54 | __lttng_ust_plibc_dlclose = dlsym(RTLD_NEXT, "dlclose"); |
| 55 | if (__lttng_ust_plibc_dlclose == NULL) { |
| 56 | fprintf(stderr, "%s\n", dlerror()); |
| 57 | return -1; |
| 58 | } |
| 59 | } |
| 60 | return __lttng_ust_plibc_dlclose(handle); |
| 61 | } |
| 62 | |
| 63 | static |
| 64 | void *lttng_ust_baddr_handle(void) |
| 65 | { |
| 66 | if (!__lttng_ust_baddr_handle) { |
| 67 | __lttng_ust_baddr_handle = _lttng_ust_dl_libc_dlopen( |
| 68 | "liblttng-ust-baddr.so.0", RTLD_NOW | RTLD_GLOBAL); |
| 69 | if (__lttng_ust_baddr_handle == NULL) |
| 70 | fprintf(stderr, "%s\n", dlerror()); |
| 71 | } |
| 72 | return __lttng_ust_baddr_handle; |
| 73 | } |
| 74 | |
| 75 | static |
| 76 | int lttng_ust_baddr_push(void *so_base, const char *so_name) |
| 77 | { |
| 78 | static int |
| 79 | (*lttng_ust_baddr_push_fn)(void *so_base, const char *so_name); |
| 80 | if (!lttng_ust_baddr_push_fn) { |
| 81 | void *baddr_handle = lttng_ust_baddr_handle(); |
| 82 | if (baddr_handle) { |
| 83 | lttng_ust_baddr_push_fn = dlsym(baddr_handle, |
| 84 | "lttng_ust_push_baddr"); |
| 85 | if (lttng_ust_baddr_push_fn == NULL) |
| 86 | fprintf(stderr, "%s\n", dlerror()); |
| 87 | } |
| 88 | if (!lttng_ust_baddr_push_fn) |
| 89 | return -1; |
| 90 | } |
| 91 | return lttng_ust_baddr_push_fn(so_base, so_name); |
| 92 | } |
| 93 | |
| 94 | static |
| 95 | int lttng_ust_baddr_pop(void *so_base) |
| 96 | { |
| 97 | static int |
| 98 | (*lttng_ust_baddr_pop_fn)(void *so_base); |
| 99 | if (!lttng_ust_baddr_pop_fn) { |
| 100 | void *baddr_handle = lttng_ust_baddr_handle(); |
| 101 | if (baddr_handle) { |
| 102 | lttng_ust_baddr_pop_fn = dlsym(baddr_handle, |
| 103 | "lttng_ust_pop_baddr"); |
| 104 | if (lttng_ust_baddr_pop_fn == NULL) |
| 105 | fprintf(stderr, "%s\n", dlerror()); |
| 106 | } |
| 107 | if (!lttng_ust_baddr_pop_fn) |
| 108 | return -1; |
| 109 | } |
| 110 | return lttng_ust_baddr_pop_fn(so_base); |
| 111 | } |
| 112 | |
| 113 | void *dlopen(const char *filename, int flag) |
| 114 | { |
| 115 | void *handle = _lttng_ust_dl_libc_dlopen(filename, flag); |
| 116 | if (handle) { |
| 117 | struct link_map *p = NULL; |
| 118 | if (dlinfo(handle, RTLD_DI_LINKMAP, &p) != -1 && p != NULL |
| 119 | && p->l_addr != 0) |
| 120 | lttng_ust_baddr_push((void *) p->l_addr, p->l_name); |
| 121 | } |
| 122 | return handle; |
| 123 | } |
| 124 | |
| 125 | int dlclose(void *handle) |
| 126 | { |
| 127 | if (handle) { |
| 128 | struct link_map *p = NULL; |
| 129 | if (dlinfo(handle, RTLD_DI_LINKMAP, &p) != -1 && p != NULL |
| 130 | && p->l_addr != 0) |
| 131 | lttng_ust_baddr_pop((void *) p->l_addr); |
| 132 | } |
| 133 | return _lttng_ust_dl_libc_dlclose(handle); |
| 134 | } |
| 135 | |
| 136 | static void __attribute__((destructor)) |
| 137 | lttng_ust_baddr_handle_fini(void); |
| 138 | static void |
| 139 | lttng_ust_baddr_handle_fini(void) |
| 140 | { |
| 141 | if (__lttng_ust_baddr_handle) { |
| 142 | int ret = _lttng_ust_dl_libc_dlclose(__lttng_ust_baddr_handle); |
| 143 | if (ret) |
| 144 | fprintf(stderr, "%s\n", dlerror()); |
| 145 | } |
| 146 | } |