diff options
Diffstat (limited to 'tools/relocate-rela.c')
| -rw-r--r-- | tools/relocate-rela.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/tools/relocate-rela.c b/tools/relocate-rela.c new file mode 100644 index 0000000..93b4c39 --- /dev/null +++ b/tools/relocate-rela.c @@ -0,0 +1,189 @@ +/* + * Copyright 2013 Freescale Semiconductor, Inc. + * + * SPDX-License-Identifier: GPL-2.0+ BSD-2-Clause + * + * 64-bit and little-endian target only until we need to support a different + * arch that needs this. + */ + +#include <elf.h> +#include <errno.h> +#include <inttypes.h> +#include <stdarg.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#ifndef R_AARCH64_RELATIVE +#define R_AARCH64_RELATIVE 1027 +#endif + +static const bool debug_en; + +static void debug(const char *fmt, ...) +{ + va_list args; + + va_start(args, fmt); + if (debug_en) + vprintf(fmt, args); +} + +static bool supported_rela(Elf64_Rela *rela) +{ + uint64_t mask = 0xffffffffULL; /* would be different on 32-bit */ + uint32_t type = rela->r_info & mask; + + switch (type) { +#ifdef R_AARCH64_RELATIVE + case R_AARCH64_RELATIVE: + return true; +#endif + default: + fprintf(stderr, "warning: unsupported relocation type %" + PRIu32 " at %" PRIx64 "\n", + type, rela->r_offset); + + return false; + } +} + +static inline uint64_t swap64(uint64_t val) +{ + return ((val >> 56) & 0x00000000000000ffULL) | + ((val >> 40) & 0x000000000000ff00ULL) | + ((val >> 24) & 0x0000000000ff0000ULL) | + ((val >> 8) & 0x00000000ff000000ULL) | + ((val << 8) & 0x000000ff00000000ULL) | + ((val << 24) & 0x0000ff0000000000ULL) | + ((val << 40) & 0x00ff000000000000ULL) | + ((val << 56) & 0xff00000000000000ULL); +} + +#if __BYTE_ORDER == __LITTLE_ENDIAN +static inline uint64_t be64(uint64_t val) +{ + return swap64(val); +} + +static inline uint64_t le64(uint64_t val) +{ + return val; +} +#else +static inline uint64_t le64(uint64_t val) +{ + return swap64(val); +} + +static inline uint64_t be64(uint64_t val) +{ + return val; +} +#endif + +static bool read_num(const char *str, uint64_t *num) +{ + char *endptr; + *num = strtoull(str, &endptr, 16); + return str[0] && !endptr[0]; +} + +int main(int argc, char **argv) +{ + FILE *f; + int i, num; + uint64_t rela_start, rela_end, text_base; + + if (argc != 5) { + fprintf(stderr, "Statically apply ELF rela relocations\n"); + fprintf(stderr, "Usage: %s <bin file> <text base> " \ + "<rela start> <rela end>\n", argv[0]); + fprintf(stderr, "All numbers in hex.\n"); + return 1; + } + + f = fopen(argv[1], "r+b"); + if (!f) { + fprintf(stderr, "%s: Cannot open %s: %s\n", + argv[0], argv[1], strerror(errno)); + return 2; + } + + if (!read_num(argv[2], &text_base) || + !read_num(argv[3], &rela_start) || + !read_num(argv[4], &rela_end)) { + fprintf(stderr, "%s: bad number\n", argv[0]); + return 3; + } + + if (rela_start > rela_end || rela_start < text_base || + (rela_end - rela_start) % 24) { + fprintf(stderr, "%s: bad rela bounds\n", argv[0]); + return 3; + } + + rela_start -= text_base; + rela_end -= text_base; + + num = (rela_end - rela_start) / sizeof(Elf64_Rela); + + for (i = 0; i < num; i++) { + Elf64_Rela rela, swrela; + uint64_t pos = rela_start + sizeof(Elf64_Rela) * i; + uint64_t addr; + + if (fseek(f, pos, SEEK_SET) < 0) { + fprintf(stderr, "%s: %s: seek to %" PRIx64 + " failed: %s\n", + argv[0], argv[1], pos, strerror(errno)); + } + + if (fread(&rela, sizeof(rela), 1, f) != 1) { + fprintf(stderr, "%s: %s: read rela failed at %" + PRIx64 "\n", + argv[0], argv[1], pos); + return 4; + } + + swrela.r_offset = le64(rela.r_offset); + swrela.r_info = le64(rela.r_info); + swrela.r_addend = le64(rela.r_addend); + + if (!supported_rela(&swrela)) + continue; + + debug("Rela %" PRIx64 " %" PRIu64 " %" PRIx64 "\n", + swrela.r_offset, swrela.r_info, swrela.r_addend); + + if (swrela.r_offset < text_base) { + fprintf(stderr, "%s: %s: bad rela at %" PRIx64 "\n", + argv[0], argv[1], pos); + return 4; + } + + addr = swrela.r_offset - text_base; + + if (fseek(f, addr, SEEK_SET) < 0) { + fprintf(stderr, "%s: %s: seek to %" + PRIx64 " failed: %s\n", + argv[0], argv[1], addr, strerror(errno)); + } + + if (fwrite(&rela.r_addend, sizeof(rela.r_addend), 1, f) != 1) { + fprintf(stderr, "%s: %s: write failed at %" PRIx64 "\n", + argv[0], argv[1], addr); + return 4; + } + } + + if (fclose(f) < 0) { + fprintf(stderr, "%s: %s: close failed: %s\n", + argv[0], argv[1], strerror(errno)); + return 4; + } + + return 0; +} |