diff options
Diffstat (limited to 'arch/powerpc/kernel/module_32.c')
| -rw-r--r-- | arch/powerpc/kernel/module_32.c | 97 |
1 files changed, 76 insertions, 21 deletions
diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c index f417afc08d33..ea6536171778 100644 --- a/arch/powerpc/kernel/module_32.c +++ b/arch/powerpc/kernel/module_32.c @@ -18,6 +18,7 @@ #include <linux/bug.h> #include <linux/sort.h> #include <asm/setup.h> +#include <asm/code-patching.h> /* Count how many different relocations (different symbol, different addend) */ @@ -98,7 +99,7 @@ static unsigned long get_plt_size(const Elf32_Ehdr *hdr, /* Sort the relocation information based on a symbol and * addend key. This is a stable O(n*log n) complexity - * alogrithm but it will reduce the complexity of + * algorithm but it will reduce the complexity of * count_relocs() to linear complexity O(n) */ sort((void *)hdr + sechdrs[i].sh_offset, @@ -174,15 +175,25 @@ static uint32_t do_plt_call(void *location, entry++; } - entry->jump[0] = PPC_RAW_LIS(_R12, PPC_HA(val)); - entry->jump[1] = PPC_RAW_ADDI(_R12, _R12, PPC_LO(val)); - entry->jump[2] = PPC_RAW_MTCTR(_R12); - entry->jump[3] = PPC_RAW_BCTR(); + if (patch_instruction(&entry->jump[0], ppc_inst(PPC_RAW_LIS(_R12, PPC_HA(val))))) + return 0; + if (patch_instruction(&entry->jump[1], ppc_inst(PPC_RAW_ADDI(_R12, _R12, PPC_LO(val))))) + return 0; + if (patch_instruction(&entry->jump[2], ppc_inst(PPC_RAW_MTCTR(_R12)))) + return 0; + if (patch_instruction(&entry->jump[3], ppc_inst(PPC_RAW_BCTR()))) + return 0; pr_debug("Initialized plt for 0x%x at %p\n", val, entry); return (uint32_t)entry; } +static int patch_location_16(uint32_t *loc, u16 value) +{ + loc = PTR_ALIGN_DOWN(loc, sizeof(u32)); + return patch_instruction(loc, ppc_inst((*loc & 0xffff0000) | value)); +} + int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, @@ -216,44 +227,46 @@ int apply_relocate_add(Elf32_Shdr *sechdrs, case R_PPC_ADDR16_LO: /* Low half of the symbol */ - *(uint16_t *)location = value; + if (patch_location_16(location, PPC_LO(value))) + return -EFAULT; break; case R_PPC_ADDR16_HI: /* Higher half of the symbol */ - *(uint16_t *)location = (value >> 16); + if (patch_location_16(location, PPC_HI(value))) + return -EFAULT; break; case R_PPC_ADDR16_HA: - /* Sign-adjusted lower 16 bits: PPC ELF ABI says: - (((x >> 16) + ((x & 0x8000) ? 1 : 0))) & 0xFFFF. - This is the same, only sane. - */ - *(uint16_t *)location = (value + 0x8000) >> 16; + if (patch_location_16(location, PPC_HA(value))) + return -EFAULT; break; case R_PPC_REL24: if ((int)(value - (uint32_t)location) < -0x02000000 - || (int)(value - (uint32_t)location) >= 0x02000000) + || (int)(value - (uint32_t)location) >= 0x02000000) { value = do_plt_call(location, value, sechdrs, module); + if (!value) + return -EFAULT; + } /* Only replace bits 2 through 26 */ pr_debug("REL24 value = %08X. location = %08X\n", value, (uint32_t)location); pr_debug("Location before: %08X.\n", *(uint32_t *)location); - *(uint32_t *)location - = (*(uint32_t *)location & ~0x03fffffc) - | ((value - (uint32_t)location) - & 0x03fffffc); + value = (*(uint32_t *)location & ~PPC_LI_MASK) | + PPC_LI(value - (uint32_t)location); + + if (patch_instruction(location, ppc_inst(value))) + return -EFAULT; + pr_debug("Location after: %08X.\n", *(uint32_t *)location); pr_debug("ie. jump to %08X+%08X = %08X\n", - *(uint32_t *)location & 0x03fffffc, - (uint32_t)location, - (*(uint32_t *)location & 0x03fffffc) - + (uint32_t)location); + *(uint32_t *)PPC_LI((uint32_t)location), (uint32_t)location, + (*(uint32_t *)PPC_LI((uint32_t)location)) + (uint32_t)location); break; case R_PPC_REL32: @@ -273,6 +286,40 @@ int apply_relocate_add(Elf32_Shdr *sechdrs, } #ifdef CONFIG_DYNAMIC_FTRACE +notrace int module_trampoline_target(struct module *mod, unsigned long addr, + unsigned long *target) +{ + ppc_inst_t jmp[4]; + + /* Find where the trampoline jumps to */ + if (copy_inst_from_kernel_nofault(jmp, (void *)addr)) + return -EFAULT; + if (__copy_inst_from_kernel_nofault(jmp + 1, (void *)addr + 4)) + return -EFAULT; + if (__copy_inst_from_kernel_nofault(jmp + 2, (void *)addr + 8)) + return -EFAULT; + if (__copy_inst_from_kernel_nofault(jmp + 3, (void *)addr + 12)) + return -EFAULT; + + /* verify that this is what we expect it to be */ + if ((ppc_inst_val(jmp[0]) & 0xffff0000) != PPC_RAW_LIS(_R12, 0)) + return -EINVAL; + if ((ppc_inst_val(jmp[1]) & 0xffff0000) != PPC_RAW_ADDI(_R12, _R12, 0)) + return -EINVAL; + if (ppc_inst_val(jmp[2]) != PPC_RAW_MTCTR(_R12)) + return -EINVAL; + if (ppc_inst_val(jmp[3]) != PPC_RAW_BCTR()) + return -EINVAL; + + addr = (ppc_inst_val(jmp[1]) & 0xffff) | ((ppc_inst_val(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, @@ -281,6 +328,14 @@ int module_finalize_ftrace(struct module *module, const Elf_Shdr *sechdrs) if (!module->arch.tramp) return -ENOENT; +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS + module->arch.tramp_regs = do_plt_call(module->core_layout.base, + (unsigned long)ftrace_regs_caller, + sechdrs, module); + if (!module->arch.tramp_regs) + return -ENOENT; +#endif + return 0; } #endif |