diff options
Diffstat (limited to 'libc/sysdeps/linux')
| -rw-r--r-- | libc/sysdeps/linux/arm/Makefile.arch | 2 | ||||
| -rw-r--r-- | libc/sysdeps/linux/arm/find_got.c | 72 |
2 files changed, 73 insertions, 1 deletions
diff --git a/libc/sysdeps/linux/arm/Makefile.arch b/libc/sysdeps/linux/arm/Makefile.arch index f9ac88b84..40a0184cb 100644 --- a/libc/sysdeps/linux/arm/Makefile.arch +++ b/libc/sysdeps/linux/arm/Makefile.arch @@ -23,7 +23,7 @@ $(eval $(call cache-output-var,IS_EABI,$(CC_IS_EABI_CHECK) -x c - -E -dM </dev/n CSRC-$(IS_EABI) += aeabi_assert.c aeabi_atexit.c aeabi_errno_addr.c \ aeabi_localeconv.c aeabi_memclr.c aeabi_memcpy.c \ - aeabi_memmove.c aeabi_memset.c find_exidx.c + aeabi_memmove.c aeabi_memset.c find_exidx.c find_got.c SSRC-$(IS_EABI) += syscall-eabi.S CSRC-$(if $(IS_EABI),,y)) += syscall.c ARCH_OBJ_FILTEROUT-$(IS_EABI) := syscall.c diff --git a/libc/sysdeps/linux/arm/find_got.c b/libc/sysdeps/linux/arm/find_got.c new file mode 100644 index 000000000..129238872 --- /dev/null +++ b/libc/sysdeps/linux/arm/find_got.c @@ -0,0 +1,72 @@ +/* Copyright (C) 2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <link.h> +#include <unwind.h> + +#if __FDPIC__ +#include <bits/elf-fdpic.h> + +struct got_callback_data +{ + _Unwind_Ptr pc; + _Unwind_Ptr got; +}; + +static __always_inline int +__dl_addr_in_loadaddr(void *p, struct elf32_fdpic_loadaddr loadaddr) +{ + struct elf32_fdpic_loadmap *map = loadaddr.map; + int c; + + for (c = 0; c < map->nsegs; c++) + if ((void *)map->segs[c].addr <= p && + (char *)p < (char *)map->segs[c].addr + map->segs[c].p_memsz) + return 1; + + return 0; +} + +/* Callback to return the GOT value if the module contains PC. */ +static int +find_got_callback (struct dl_phdr_info * info, size_t size, void * ptr) +{ + int match = 0; + struct got_callback_data *data = (struct got_callback_data *) ptr; + + if (__dl_addr_in_loadaddr((void *) data->pc, info->dlpi_addr)) { + match = 1; + data->got = (_Unwind_Ptr) info->dlpi_addr.got_value; + } + + return match; +} + +/* Find the GOT that corresponds to the module containing PC. */ +_Unwind_Ptr __gnu_Unwind_Find_got (_Unwind_Ptr pc); +_Unwind_Ptr __gnu_Unwind_Find_got (_Unwind_Ptr pc) +{ + struct got_callback_data data; + + data.pc = pc; + if (dl_iterate_phdr (find_got_callback, &data) <= 0) + return 0; + + return data.got; +} +#endif + |