diff options
Diffstat (limited to 'arch/powerpc/kernel/module_32.c')
| -rw-r--r-- | arch/powerpc/kernel/module_32.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c index f417afc08d33..5dedd76346b2 100644 --- a/arch/powerpc/kernel/module_32.c +++ b/arch/powerpc/kernel/module_32.c @@ -273,6 +273,31 @@ int apply_relocate_add(Elf32_Shdr *sechdrs, } #ifdef CONFIG_DYNAMIC_FTRACE +int module_trampoline_target(struct module *mod, unsigned long addr, + unsigned long *target) +{ + unsigned int jmp[4]; + + /* Find where the trampoline jumps to */ + if (copy_from_kernel_nofault(jmp, (void *)addr, sizeof(jmp))) + return -EFAULT; + + /* verify that this is what we expect it to be */ + if ((jmp[0] & 0xffff0000) != PPC_RAW_LIS(_R12, 0) || + (jmp[1] & 0xffff0000) != PPC_RAW_ADDI(_R12, _R12, 0) || + jmp[2] != PPC_RAW_MTCTR(_R12) || + jmp[3] != PPC_RAW_BCTR()) + return -EINVAL; + + addr = (jmp[1] & 0xffff) | ((jmp[0] & 0xffff) << 16); + if (addr & 0x8000) + addr -= 0x10000; + + *target = addr; + + return 0; +} + int module_finalize_ftrace(struct module *module, const Elf_Shdr *sechdrs) { module->arch.tramp = do_plt_call(module->core_layout.base, |