Patrick Williams | d8c66bc | 2016-06-20 12:57:21 -0500 | [diff] [blame^] | 1 | From 59d4b8c48e5040af7e02b34eb26ea602ec82a38e Mon Sep 17 00:00:00 2001 |
| 2 | From: James Cowgill <james410@cowgill.org.uk> |
| 3 | Date: Mon, 5 Jan 2015 15:17:02 +0000 |
| 4 | Subject: [PATCH 3/3] Add mips n64 relocation format hack |
| 5 | |
| 6 | MIPSEL N64 ELF files use a slightly different format for storing relocation |
| 7 | entries which is incompatible with the normal R_SYM / R_INFO macros. |
| 8 | To workaround this, we rearrange the bytes in the relocation's r_info field |
| 9 | when reading and writing the relocations. |
| 10 | |
| 11 | This patch also ensures that strip.c sets the correct value of e_machine |
| 12 | before manipulating relocations so that these changes take effect. |
| 13 | |
| 14 | Signed-off-by: James Cowgill <james410@cowgill.org.uk> |
| 15 | --- |
| 16 | libelf/gelf_getrel.c | 25 +++++++++++++++++++++++-- |
| 17 | libelf/gelf_getrela.c | 25 +++++++++++++++++++++++-- |
| 18 | libelf/gelf_update_rel.c | 20 +++++++++++++++++++- |
| 19 | libelf/gelf_update_rela.c | 20 +++++++++++++++++++- |
| 20 | src/strip.c | 17 +++++++++++++++++ |
| 21 | 5 files changed, 101 insertions(+), 6 deletions(-) |
| 22 | |
| 23 | Index: elfutils-0.164/libelf/gelf_getrel.c |
| 24 | =================================================================== |
| 25 | --- elfutils-0.164.orig/libelf/gelf_getrel.c |
| 26 | +++ elfutils-0.164/libelf/gelf_getrel.c |
| 27 | @@ -36,6 +36,7 @@ |
| 28 | |
| 29 | #include "libelfP.h" |
| 30 | |
| 31 | +#define EF_MIPS_ABI 0x0000F000 |
| 32 | |
| 33 | GElf_Rel * |
| 34 | gelf_getrel (Elf_Data *data, int ndx, GElf_Rel *dst) |
| 35 | @@ -89,8 +90,28 @@ gelf_getrel (Elf_Data *data, int ndx, GE |
| 36 | result = NULL; |
| 37 | } |
| 38 | else |
| 39 | - result = memcpy (dst, &((Elf64_Rel *) data_scn->d.d_buf)[ndx], |
| 40 | - sizeof (Elf64_Rel)); |
| 41 | + { |
| 42 | + GElf_Ehdr hdr; |
| 43 | + result = memcpy (dst, &((Elf64_Rel *) data_scn->d.d_buf)[ndx], |
| 44 | + sizeof (Elf64_Rel)); |
| 45 | + |
| 46 | + if (gelf_getehdr(scn->elf, &hdr) != NULL && |
| 47 | + hdr.e_ident[EI_DATA] == ELFDATA2LSB && |
| 48 | + hdr.e_machine == EM_MIPS && |
| 49 | + (hdr.e_flags & EF_MIPS_ABI) == 0) |
| 50 | + { |
| 51 | + /* |
| 52 | + * The relocation format is mangled on MIPSEL N64 |
| 53 | + * We'll adjust it so at least R_SYM will work on it |
| 54 | + */ |
| 55 | + GElf_Xword r_info = dst->r_info; |
| 56 | + dst->r_info = (r_info << 32) | |
| 57 | + ((r_info >> 8) & 0xFF000000) | |
| 58 | + ((r_info >> 24) & 0x00FF0000) | |
| 59 | + ((r_info >> 40) & 0x0000FF00) | |
| 60 | + ((r_info >> 56) & 0x000000FF); |
| 61 | + } |
| 62 | + } |
| 63 | } |
| 64 | |
| 65 | rwlock_unlock (scn->elf->lock); |
| 66 | Index: elfutils-0.164/libelf/gelf_getrela.c |
| 67 | =================================================================== |
| 68 | --- elfutils-0.164.orig/libelf/gelf_getrela.c |
| 69 | +++ elfutils-0.164/libelf/gelf_getrela.c |
| 70 | @@ -36,6 +36,7 @@ |
| 71 | |
| 72 | #include "libelfP.h" |
| 73 | |
| 74 | +#define EF_MIPS_ABI 0x0000F000 |
| 75 | |
| 76 | GElf_Rela * |
| 77 | gelf_getrela (Elf_Data *data, int ndx, GElf_Rela *dst) |
| 78 | @@ -90,8 +91,28 @@ gelf_getrela (Elf_Data *data, int ndx, G |
| 79 | result = NULL; |
| 80 | } |
| 81 | else |
| 82 | - result = memcpy (dst, &((Elf64_Rela *) data_scn->d.d_buf)[ndx], |
| 83 | - sizeof (Elf64_Rela)); |
| 84 | + { |
| 85 | + GElf_Ehdr hdr; |
| 86 | + result = memcpy (dst, &((Elf64_Rela *) data_scn->d.d_buf)[ndx], |
| 87 | + sizeof (Elf64_Rela)); |
| 88 | + |
| 89 | + if (gelf_getehdr(scn->elf, &hdr) != NULL && |
| 90 | + hdr.e_ident[EI_DATA] == ELFDATA2LSB && |
| 91 | + hdr.e_machine == EM_MIPS && |
| 92 | + (hdr.e_flags & EF_MIPS_ABI) == 0) |
| 93 | + { |
| 94 | + /* |
| 95 | + * The relocation format is mangled on MIPSEL N64 |
| 96 | + * We'll adjust it so at least R_SYM will work on it |
| 97 | + */ |
| 98 | + GElf_Xword r_info = dst->r_info; |
| 99 | + dst->r_info = (r_info << 32) | |
| 100 | + ((r_info >> 8) & 0xFF000000) | |
| 101 | + ((r_info >> 24) & 0x00FF0000) | |
| 102 | + ((r_info >> 40) & 0x0000FF00) | |
| 103 | + ((r_info >> 56) & 0x000000FF); |
| 104 | + } |
| 105 | + } |
| 106 | } |
| 107 | |
| 108 | rwlock_unlock (scn->elf->lock); |
| 109 | Index: elfutils-0.164/libelf/gelf_update_rel.c |
| 110 | =================================================================== |
| 111 | --- elfutils-0.164.orig/libelf/gelf_update_rel.c |
| 112 | +++ elfutils-0.164/libelf/gelf_update_rel.c |
| 113 | @@ -36,6 +36,7 @@ |
| 114 | |
| 115 | #include "libelfP.h" |
| 116 | |
| 117 | +#define EF_MIPS_ABI 0x0000F000 |
| 118 | |
| 119 | int |
| 120 | gelf_update_rel (Elf_Data *dst, int ndx, GElf_Rel *src) |
| 121 | @@ -86,6 +87,9 @@ gelf_update_rel (Elf_Data *dst, int ndx, |
| 122 | } |
| 123 | else |
| 124 | { |
| 125 | + GElf_Ehdr hdr; |
| 126 | + GElf_Rel value = *src; |
| 127 | + |
| 128 | /* Check whether we have to resize the data buffer. */ |
| 129 | if (INVALID_NDX (ndx, Elf64_Rel, &data_scn->d)) |
| 130 | { |
| 131 | @@ -93,7 +97,21 @@ gelf_update_rel (Elf_Data *dst, int ndx, |
| 132 | goto out; |
| 133 | } |
| 134 | |
| 135 | - ((Elf64_Rel *) data_scn->d.d_buf)[ndx] = *src; |
| 136 | + if (gelf_getehdr(scn->elf, &hdr) != NULL && |
| 137 | + hdr.e_ident[EI_DATA] == ELFDATA2LSB && |
| 138 | + hdr.e_machine == EM_MIPS && |
| 139 | + (hdr.e_flags & EF_MIPS_ABI) == 0) |
| 140 | + { |
| 141 | + /* Undo the MIPSEL N64 hack from gelf_getrel */ |
| 142 | + GElf_Xword r_info = value.r_info; |
| 143 | + value.r_info = (r_info >> 32) | |
| 144 | + ((r_info << 8) & 0x000000FF00000000) | |
| 145 | + ((r_info << 24) & 0x0000FF0000000000) | |
| 146 | + ((r_info << 40) & 0x00FF000000000000) | |
| 147 | + ((r_info << 56) & 0xFF00000000000000); |
| 148 | + } |
| 149 | + |
| 150 | + ((Elf64_Rel *) data_scn->d.d_buf)[ndx] = value; |
| 151 | } |
| 152 | |
| 153 | result = 1; |
| 154 | Index: elfutils-0.164/libelf/gelf_update_rela.c |
| 155 | =================================================================== |
| 156 | --- elfutils-0.164.orig/libelf/gelf_update_rela.c |
| 157 | +++ elfutils-0.164/libelf/gelf_update_rela.c |
| 158 | @@ -36,6 +36,7 @@ |
| 159 | |
| 160 | #include "libelfP.h" |
| 161 | |
| 162 | +#define EF_MIPS_ABI 0x0000F000 |
| 163 | |
| 164 | int |
| 165 | gelf_update_rela (Elf_Data *dst, int ndx, GElf_Rela *src) |
| 166 | @@ -89,6 +90,9 @@ gelf_update_rela (Elf_Data *dst, int ndx |
| 167 | } |
| 168 | else |
| 169 | { |
| 170 | + GElf_Ehdr hdr; |
| 171 | + GElf_Rela value = *src; |
| 172 | + |
| 173 | /* Check whether we have to resize the data buffer. */ |
| 174 | if (INVALID_NDX (ndx, Elf64_Rela, &data_scn->d)) |
| 175 | { |
| 176 | @@ -96,7 +100,21 @@ gelf_update_rela (Elf_Data *dst, int ndx |
| 177 | goto out; |
| 178 | } |
| 179 | |
| 180 | - ((Elf64_Rela *) data_scn->d.d_buf)[ndx] = *src; |
| 181 | + if (gelf_getehdr(scn->elf, &hdr) != NULL && |
| 182 | + hdr.e_ident[EI_DATA] == ELFDATA2LSB && |
| 183 | + hdr.e_machine == EM_MIPS && |
| 184 | + (hdr.e_flags & EF_MIPS_ABI) == 0) |
| 185 | + { |
| 186 | + /* Undo the MIPSEL N64 hack from gelf_getrel */ |
| 187 | + GElf_Xword r_info = value.r_info; |
| 188 | + value.r_info = (r_info >> 32) | |
| 189 | + ((r_info << 8) & 0x000000FF00000000) | |
| 190 | + ((r_info << 24) & 0x0000FF0000000000) | |
| 191 | + ((r_info << 40) & 0x00FF000000000000) | |
| 192 | + ((r_info << 56) & 0xFF00000000000000); |
| 193 | + } |
| 194 | + |
| 195 | + ((Elf64_Rela *) data_scn->d.d_buf)[ndx] = value; |
| 196 | } |
| 197 | |
| 198 | result = 1; |
| 199 | Index: elfutils-0.164/src/strip.c |
| 200 | =================================================================== |
| 201 | --- elfutils-0.164.orig/src/strip.c |
| 202 | +++ elfutils-0.164/src/strip.c |
| 203 | @@ -546,6 +546,23 @@ handle_elf (int fd, Elf *elf, const char |
| 204 | goto fail; |
| 205 | } |
| 206 | |
| 207 | + /* Copy identity part of the ELF header now */ |
| 208 | + newehdr = gelf_getehdr (newelf, &newehdr_mem); |
| 209 | + if (newehdr == NULL) |
| 210 | + INTERNAL_ERROR (fname); |
| 211 | + |
| 212 | + memcpy (newehdr->e_ident, ehdr->e_ident, EI_NIDENT); |
| 213 | + newehdr->e_type = ehdr->e_type; |
| 214 | + newehdr->e_machine = ehdr->e_machine; |
| 215 | + newehdr->e_version = ehdr->e_version; |
| 216 | + |
| 217 | + if (gelf_update_ehdr (newelf, newehdr) == 0) |
| 218 | + { |
| 219 | + error (0, 0, gettext ("%s: error while creating ELF header: %s"), |
| 220 | + fname, elf_errmsg (-1)); |
| 221 | + return 1; |
| 222 | + } |
| 223 | + |
| 224 | /* Copy over the old program header if needed. */ |
| 225 | if (ehdr->e_type != ET_REL) |
| 226 | for (cnt = 0; cnt < phnum; ++cnt) |