| Raghu Gandham | 405b802 | 2012-07-25 18:16:42 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2006 The Android Open Source Project |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * * Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * * Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in |
| 12 | * the documentation and/or other materials provided with the |
| 13 | * distribution. |
| 14 | * |
| 15 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 16 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 17 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 18 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 19 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 20 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| 21 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| 22 | * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| 23 | * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| 24 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| 25 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 26 | * SUCH DAMAGE. |
| 27 | */ |
| 28 | |
| 29 | #include <sys/types.h> |
| 30 | #include <linux/elf.h> |
| 31 | |
| 32 | /* TODO: Move this into a header that linker.h can also pull it in. |
| 33 | * Silly to have same struct in 2 places. This is temporary. */ |
| 34 | struct dl_phdr_info |
| 35 | { |
| 36 | Elf32_Addr dlpi_addr; |
| 37 | const char *dlpi_name; |
| 38 | const Elf32_Phdr *dlpi_phdr; |
| 39 | Elf32_Half dlpi_phnum; |
| 40 | }; |
| 41 | |
| 42 | /* Dynamic binaries get this from the dynamic linker (system/linker), which |
| 43 | * we don't pull in for static bins. We also don't have a list of so's to |
| 44 | * iterate over, since there's really only a single monolithic blob of |
| 45 | * code/data. |
| 46 | * |
| 47 | * All we need to do is to find where the executable is in memory, and grab the |
| 48 | * phdr and phnum from there. |
| 49 | */ |
| 50 | |
| 51 | /* ld provides this to us in the default link script */ |
| 52 | extern void *__executable_start; |
| 53 | |
| 54 | int |
| 55 | dl_iterate_phdr(int (*cb)(struct dl_phdr_info *info, size_t size, void *data), |
| 56 | void *data) |
| 57 | { |
| 58 | struct dl_phdr_info dl_info; |
| 59 | Elf32_Ehdr *ehdr = (Elf32_Ehdr *) &__executable_start; |
| 60 | Elf32_Phdr *phdr = (Elf32_Phdr *)((unsigned long)ehdr + ehdr->e_phoff); |
| 61 | |
| 62 | /* TODO: again, copied from linker.c. Find a better home for this |
| 63 | * later. */ |
| 64 | if (ehdr->e_ident[EI_MAG0] != ELFMAG0) return -1; |
| 65 | if (ehdr->e_ident[EI_MAG1] != ELFMAG1) return -1; |
| 66 | if (ehdr->e_ident[EI_MAG2] != ELFMAG2) return -1; |
| 67 | if (ehdr->e_ident[EI_MAG3] != ELFMAG3) return -1; |
| 68 | |
| 69 | dl_info.dlpi_addr = 0; |
| 70 | dl_info.dlpi_name = NULL; |
| 71 | dl_info.dlpi_phdr = phdr; |
| 72 | dl_info.dlpi_phnum = ehdr->e_phnum; |
| 73 | return cb(&dl_info, sizeof (struct dl_phdr_info), data); |
| 74 | } |