diff options
Diffstat (limited to 'backends/ppc_symbol.c')
| -rw-r--r-- | backends/ppc_symbol.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/backends/ppc_symbol.c b/backends/ppc_symbol.c new file mode 100644 index 00000000..c17ab374 --- /dev/null +++ b/backends/ppc_symbol.c @@ -0,0 +1,165 @@ +/* PPC specific symbolic name handling. + Copyright (C) 2004, 2005, 2007, 2014 Red Hat, Inc. + This file is part of elfutils. + Written by Ulrich Drepper <drepper@redhat.com>, 2004. + + This file is free software; you can redistribute it and/or modify + it under the terms of either + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at + your option) any later version + + or + + * the GNU General Public License as published by the Free + Software Foundation; either version 2 of the License, or (at + your option) any later version + + or both in parallel, as here. + + elfutils is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received copies of the GNU General Public License and + the GNU Lesser General Public License along with this program. If + not, see <http://www.gnu.org/licenses/>. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <assert.h> +#include <elf.h> +#include <stddef.h> +#include <string.h> + +#define BACKEND ppc_ +#include "libebl_CPU.h" + + +/* Check for the simple reloc types. */ +Elf_Type +ppc_reloc_simple_type (Ebl *ebl __attribute__ ((unused)), int type) +{ + switch (type) + { + case R_PPC_ADDR32: + case R_PPC_UADDR32: + return ELF_T_WORD; + case R_PPC_UADDR16: + return ELF_T_HALF; + default: + return ELF_T_NUM; + } +} + + +const char * +ppc_dynamic_tag_name (int64_t tag, char *buf __attribute__ ((unused)), + size_t len __attribute__ ((unused))) +{ + switch (tag) + { + case DT_PPC_GOT: + return "PPC_GOT"; + default: + break; + } + return NULL; +} + + +bool +ppc_dynamic_tag_check (int64_t tag) +{ + return tag == DT_PPC_GOT; +} + + +/* Look for DT_PPC_GOT. */ +static bool +find_dyn_got (Elf *elf, GElf_Addr *addr) +{ + size_t phnum; + if (elf_getphdrnum (elf, &phnum) != 0) + return false; + + for (size_t i = 0; i < phnum; ++i) + { + GElf_Phdr phdr_mem; + GElf_Phdr *phdr = gelf_getphdr (elf, i, &phdr_mem); + if (phdr == NULL || phdr->p_type != PT_DYNAMIC) + continue; + + Elf_Scn *scn = gelf_offscn (elf, phdr->p_offset); + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); + Elf_Data *data = elf_getdata (scn, NULL); + if (shdr != NULL && shdr->sh_type == SHT_DYNAMIC && data != NULL) + for (unsigned int j = 0; j < shdr->sh_size / shdr->sh_entsize; ++j) + { + GElf_Dyn dyn_mem; + GElf_Dyn *dyn = gelf_getdyn (data, j, &dyn_mem); + if (dyn != NULL && dyn->d_tag == DT_PPC_GOT) + { + *addr = dyn->d_un.d_ptr; + return true; + } + } + + /* There is only one PT_DYNAMIC entry. */ + break; + } + + return false; +} + + +/* Check whether given symbol's st_value and st_size are OK despite failing + normal checks. */ +bool +ppc_check_special_symbol (Elf *elf, GElf_Ehdr *ehdr, const GElf_Sym *sym, + const char *name, const GElf_Shdr *destshdr) +{ + if (name == NULL) + return false; + + if (strcmp (name, "_GLOBAL_OFFSET_TABLE_") == 0) + { + /* In -msecure-plt mode, DT_PPC_GOT is present and must match. */ + GElf_Addr gotaddr; + if (find_dyn_got (elf, &gotaddr)) + return sym->st_value == gotaddr; + + /* In -mbss-plt mode, any place in the section is valid. */ + return true; + } + + const char *sname = elf_strptr (elf, ehdr->e_shstrndx, destshdr->sh_name); + if (sname == NULL) + return false; + + if (strcmp (name, "_SDA_BASE_") == 0) + return (strcmp (sname, ".sdata") == 0 + && sym->st_value == destshdr->sh_addr + 0x8000 + && sym->st_size == 0); + + if (strcmp (name, "_SDA2_BASE_") == 0) + return (strcmp (sname, ".sdata2") == 0 + && sym->st_value == destshdr->sh_addr + 0x8000 + && sym->st_size == 0); + + return false; +} + + +/* Check if backend uses a bss PLT in this file. */ +bool +ppc_bss_plt_p (Elf *elf) +{ + GElf_Addr addr; + return ! find_dyn_got (elf, &addr); +} |