diff options
Diffstat (limited to 'sysdeps/x86_64/dl-machine.h')
| -rw-r--r-- | sysdeps/x86_64/dl-machine.h | 53 |
1 files changed, 47 insertions, 6 deletions
diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h index 2e2eb9fc5c..3f113f8a60 100644 --- a/sysdeps/x86_64/dl-machine.h +++ b/sysdeps/x86_64/dl-machine.h @@ -39,9 +39,12 @@ elf_machine_matches_host (const Elf64_Ehdr *ehdr) static inline Elf64_Addr __attribute__ ((unused)) elf_machine_dynamic (void) { - register Elf64_Addr addr; + Elf64_Addr addr; + + /* This works because we have our GOT address available in the small PIC + model. */ + addr = (Elf64_Addr) &_DYNAMIC; - asm ("leaq _DYNAMIC, %0\n" : "=r" (addr)); return addr; } @@ -52,10 +55,25 @@ elf_machine_load_address (void) { register Elf64_Addr addr, tmp; - asm ("leaq _dl_start, %0\n" - "leaq _dl_start(%%rip), %1\n" - "subq %0, %1\n" - : "=r" (tmp), "=r" (addr) : : "cc"); + /* The easy way is just the same as on x86: + leaq _dl_start, %0 + leaq _dl_start(%%rip), %1 + subq %0, %1 + but this does not work with binutils since we then have + a R_X86_64_32S relocation in a shared lib. + + Instead we store the address of _dl_start in the data section + and compare it with the current value that we can get via + an RIP relative addressing mode. */ + + asm ("movq .L1(%%rip), %1\n" + "0:\tleaq _dl_start(%%rip), %0\n\t" + "subq %1, %0\n\t" + ".section\t.data\n" + ".L1:\t.quad _dl_start\n\t" + ".previous\n\t" + : "=r" (addr), "=r" (tmp) : : "cc"); + return addr; } @@ -367,10 +385,33 @@ elf_machine_rela (struct link_map *map, const Elf64_Rela *reloc, break; case R_X86_64_32: *(unsigned int *) reloc_addr = value + reloc->r_addend; + if (value + reloc->r_addend > UINT_MAX) + { + const char *strtab; + + strtab = (const char *) D_PTR (map, l_info[DT_STRTAB]); + + _dl_error_printf ("\ +%s: Symbol `%s' causes overflow in R_X86_64_32 relocation\n", + rtld_progname ?: "<program name unknown>", + strtab + refsym->st_name); + } break; case R_X86_64_PC32: *(unsigned int *) reloc_addr = value + reloc->r_addend - (Elf64_Addr) reloc_addr; + if (value + reloc->r_addend - (Elf64_Addr) reloc_addr + != (unsigned int)(value + reloc->r_addend - (Elf64_Addr) reloc_addr)) + { + const char *strtab; + + strtab = (const char *) D_PTR (map, l_info[DT_STRTAB]); + + _dl_error_printf ("\ +%s: Symbol `%s' causes overflow in R_X86_64_PC32 relocation\n", + rtld_progname ?: "<program name unknown>", + strtab + refsym->st_name); + } break; case R_X86_64_COPY: if (sym == NULL) |