diff options
Diffstat (limited to 'arch/powerpc/kernel/module_32.c')
| -rw-r--r-- | arch/powerpc/kernel/module_32.c | 194 |
1 files changed, 113 insertions, 81 deletions
diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c index 2e3200ca485f..f930e3395a7f 100644 --- a/arch/powerpc/kernel/module_32.c +++ b/arch/powerpc/kernel/module_32.c @@ -1,20 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* Kernel module help for PPC. Copyright (C) 2001 Rusty Russell. - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. +*/ - This program 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 General Public License for more details. +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA -*/ #include <linux/module.h> #include <linux/moduleloader.h> #include <linux/elf.h> @@ -26,14 +17,8 @@ #include <linux/cache.h> #include <linux/bug.h> #include <linux/sort.h> - -#include "setup.h" - -#if 0 -#define DEBUGP printk -#else -#define DEBUGP(fmt , ...) -#endif +#include <asm/setup.h> +#include <asm/text-patching.h> /* Count how many different relocations (different symbol, different addend) */ @@ -83,21 +68,6 @@ static int relacmp(const void *_x, const void *_y) return 0; } -static void relaswap(void *_x, void *_y, int size) -{ - uint32_t *x, *y, tmp; - int i; - - y = (uint32_t *)_x; - x = (uint32_t *)_y; - - for (i = 0; i < sizeof(Elf32_Rela) / sizeof(uint32_t); i++) { - tmp = x[i]; - x[i] = y[i]; - y[i] = tmp; - } -} - /* Get the potential trampolines size required of the init and non-init sections */ static unsigned long get_plt_size(const Elf32_Ehdr *hdr, @@ -113,28 +83,28 @@ static unsigned long get_plt_size(const Elf32_Ehdr *hdr, for (i = 1; i < hdr->e_shnum; i++) { /* If it's called *.init*, and we're not init, we're not interested */ - if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0) + if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != NULL) != is_init) continue; /* We don't want to look at debug sections. */ - if (strstr(secstrings + sechdrs[i].sh_name, ".debug") != 0) + if (strstr(secstrings + sechdrs[i].sh_name, ".debug")) continue; if (sechdrs[i].sh_type == SHT_RELA) { - DEBUGP("Found relocations in section %u\n", i); - DEBUGP("Ptr: %p. Number: %u\n", + pr_debug("Found relocations in section %u\n", i); + pr_debug("Ptr: %p. Number: %u\n", (void *)hdr + sechdrs[i].sh_offset, sechdrs[i].sh_size / sizeof(Elf32_Rela)); /* 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, sechdrs[i].sh_size / sizeof(Elf32_Rela), - sizeof(Elf32_Rela), relacmp, relaswap); + sizeof(Elf32_Rela), relacmp, NULL); ret += count_relocs((void *)hdr + sechdrs[i].sh_offset, @@ -162,7 +132,7 @@ int module_frob_arch_sections(Elf32_Ehdr *hdr, me->arch.core_plt_section = i; } if (!me->arch.core_plt_section || !me->arch.init_plt_section) { - printk("Module doesn't contain .plt or .init.plt sections.\n"); + pr_err("Module doesn't contain .plt or .init.plt sections.\n"); return -ENOEXEC; } @@ -176,24 +146,24 @@ int module_frob_arch_sections(Elf32_Ehdr *hdr, static inline int entry_matches(struct ppc_plt_entry *entry, Elf32_Addr val) { - if (entry->jump[0] == 0x3d800000 + ((val + 0x8000) >> 16) - && entry->jump[1] == 0x398c0000 + (val & 0xffff)) - return 1; - return 0; + if (entry->jump[0] != PPC_RAW_LIS(_R12, PPC_HA(val))) + return 0; + if (entry->jump[1] != PPC_RAW_ADDI(_R12, _R12, PPC_LO(val))) + return 0; + return 1; } /* Set up a trampoline in the PLT to bounce us to the distant function */ static uint32_t do_plt_call(void *location, Elf32_Addr val, - Elf32_Shdr *sechdrs, + const Elf32_Shdr *sechdrs, struct module *mod) { struct ppc_plt_entry *entry; - DEBUGP("Doing plt for call to 0x%x at 0x%x\n", val, (unsigned int)location); + pr_debug("Doing plt for call to 0x%x at 0x%x\n", val, (unsigned int)location); /* Init, or core PLT? */ - if (location >= mod->module_core - && location < mod->module_core + mod->core_size) + if (within_module_core((unsigned long)location, mod)) entry = (void *)sechdrs[mod->arch.core_plt_section].sh_addr; else entry = (void *)sechdrs[mod->arch.init_plt_section].sh_addr; @@ -204,15 +174,25 @@ static uint32_t do_plt_call(void *location, entry++; } - entry->jump[0] = 0x3d800000+((val+0x8000)>>16); /* lis r12,sym@ha */ - entry->jump[1] = 0x398c0000 + (val&0xffff); /* addi r12,r12,sym@l*/ - entry->jump[2] = 0x7d8903a6; /* mtctr r12 */ - entry->jump[3] = 0x4e800420; /* 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; - DEBUGP("Initialized plt for 0x%x at %p\n", val, entry); + 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, @@ -225,7 +205,7 @@ int apply_relocate_add(Elf32_Shdr *sechdrs, uint32_t *location; uint32_t value; - DEBUGP("Applying ADD relocate section %u to %u\n", relsec, + pr_debug("Applying ADD relocate section %u to %u\n", relsec, sechdrs[relsec].sh_info); for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) { /* This is where to make the change */ @@ -246,44 +226,46 @@ 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 */ - DEBUGP("REL24 value = %08X. location = %08X\n", + pr_debug("REL24 value = %08X. location = %08X\n", value, (uint32_t)location); - DEBUGP("Location before: %08X.\n", + pr_debug("Location before: %08X.\n", *(uint32_t *)location); - *(uint32_t *)location - = (*(uint32_t *)location & ~0x03fffffc) - | ((value - (uint32_t)location) - & 0x03fffffc); - DEBUGP("Location after: %08X.\n", + 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); - DEBUGP("ie. jump to %08X+%08X = %08X\n", - *(uint32_t *)location & 0x03fffffc, - (uint32_t)location, - (*(uint32_t *)location & 0x03fffffc) - + (uint32_t)location); + pr_debug("ie. jump to %08X+%08X = %08X\n", + *(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: @@ -292,17 +274,67 @@ int apply_relocate_add(Elf32_Shdr *sechdrs, break; default: - printk("%s: unknown ADD relocation: %u\n", + pr_err("%s: unknown ADD relocation: %u\n", module->name, ELF32_R_TYPE(rela[i].r_info)); return -ENOEXEC; } } + + return 0; +} + #ifdef CONFIG_DYNAMIC_FTRACE - module->arch.tramp = - do_plt_call(module->module_core, - (unsigned long)ftrace_caller, - sechdrs, module); +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->mem[MOD_TEXT].base, + (unsigned long)ftrace_caller, + sechdrs, module); + if (!module->arch.tramp) + return -ENOENT; + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS + module->arch.tramp_regs = do_plt_call(module->mem[MOD_TEXT].base, + (unsigned long)ftrace_regs_caller, + sechdrs, module); + if (!module->arch.tramp_regs) + return -ENOENT; #endif + return 0; } +#endif |