diff options
Diffstat (limited to 'arch/loongarch/kernel/module.c')
| -rw-r--r-- | arch/loongarch/kernel/module.c | 375 |
1 files changed, 375 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/module.c b/arch/loongarch/kernel/module.c new file mode 100644 index 000000000000..638427ff0d51 --- /dev/null +++ b/arch/loongarch/kernel/module.c @@ -0,0 +1,375 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Author: Hanlu Li <lihanlu@loongson.cn> + * Huacai Chen <chenhuacai@loongson.cn> + * + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited + */ + +#define pr_fmt(fmt) "kmod: " fmt + +#include <linux/moduleloader.h> +#include <linux/elf.h> +#include <linux/mm.h> +#include <linux/numa.h> +#include <linux/vmalloc.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/string.h> +#include <linux/kernel.h> + +static inline bool signed_imm_check(long val, unsigned int bit) +{ + return -(1L << (bit - 1)) <= val && val < (1L << (bit - 1)); +} + +static inline bool unsigned_imm_check(unsigned long val, unsigned int bit) +{ + return val < (1UL << bit); +} + +static int rela_stack_push(s64 stack_value, s64 *rela_stack, size_t *rela_stack_top) +{ + if (*rela_stack_top >= RELA_STACK_DEPTH) + return -ENOEXEC; + + rela_stack[(*rela_stack_top)++] = stack_value; + pr_debug("%s stack_value = 0x%llx\n", __func__, stack_value); + + return 0; +} + +static int rela_stack_pop(s64 *stack_value, s64 *rela_stack, size_t *rela_stack_top) +{ + if (*rela_stack_top == 0) + return -ENOEXEC; + + *stack_value = rela_stack[--(*rela_stack_top)]; + pr_debug("%s stack_value = 0x%llx\n", __func__, *stack_value); + + return 0; +} + +static int apply_r_larch_none(struct module *mod, u32 *location, Elf_Addr v, + s64 *rela_stack, size_t *rela_stack_top, unsigned int type) +{ + return 0; +} + +static int apply_r_larch_error(struct module *me, u32 *location, Elf_Addr v, + s64 *rela_stack, size_t *rela_stack_top, unsigned int type) +{ + pr_err("%s: Unsupport relocation type %u, please add its support.\n", me->name, type); + return -EINVAL; +} + +static int apply_r_larch_32(struct module *mod, u32 *location, Elf_Addr v, + s64 *rela_stack, size_t *rela_stack_top, unsigned int type) +{ + *location = v; + return 0; +} + +static int apply_r_larch_64(struct module *mod, u32 *location, Elf_Addr v, + s64 *rela_stack, size_t *rela_stack_top, unsigned int type) +{ + *(Elf_Addr *)location = v; + return 0; +} + +static int apply_r_larch_sop_push_pcrel(struct module *mod, u32 *location, Elf_Addr v, + s64 *rela_stack, size_t *rela_stack_top, unsigned int type) +{ + return rela_stack_push(v - (u64)location, rela_stack, rela_stack_top); +} + +static int apply_r_larch_sop_push_absolute(struct module *mod, u32 *location, Elf_Addr v, + s64 *rela_stack, size_t *rela_stack_top, unsigned int type) +{ + return rela_stack_push(v, rela_stack, rela_stack_top); +} + +static int apply_r_larch_sop_push_dup(struct module *mod, u32 *location, Elf_Addr v, + s64 *rela_stack, size_t *rela_stack_top, unsigned int type) +{ + int err = 0; + s64 opr1; + + err = rela_stack_pop(&opr1, rela_stack, rela_stack_top); + if (err) + return err; + err = rela_stack_push(opr1, rela_stack, rela_stack_top); + if (err) + return err; + err = rela_stack_push(opr1, rela_stack, rela_stack_top); + if (err) + return err; + + return 0; +} + +static int apply_r_larch_sop_push_plt_pcrel(struct module *mod, u32 *location, Elf_Addr v, + s64 *rela_stack, size_t *rela_stack_top, unsigned int type) +{ + ptrdiff_t offset = (void *)v - (void *)location; + + if (offset >= SZ_128M) + v = module_emit_plt_entry(mod, v); + + if (offset < -SZ_128M) + v = module_emit_plt_entry(mod, v); + + return apply_r_larch_sop_push_pcrel(mod, location, v, rela_stack, rela_stack_top, type); +} + +static int apply_r_larch_sop(struct module *mod, u32 *location, Elf_Addr v, + s64 *rela_stack, size_t *rela_stack_top, unsigned int type) +{ + int err = 0; + s64 opr1, opr2, opr3; + + if (type == R_LARCH_SOP_IF_ELSE) { + err = rela_stack_pop(&opr3, rela_stack, rela_stack_top); + if (err) + return err; + } + + err = rela_stack_pop(&opr2, rela_stack, rela_stack_top); + if (err) + return err; + err = rela_stack_pop(&opr1, rela_stack, rela_stack_top); + if (err) + return err; + + switch (type) { + case R_LARCH_SOP_AND: + err = rela_stack_push(opr1 & opr2, rela_stack, rela_stack_top); + break; + case R_LARCH_SOP_ADD: + err = rela_stack_push(opr1 + opr2, rela_stack, rela_stack_top); + break; + case R_LARCH_SOP_SUB: + err = rela_stack_push(opr1 - opr2, rela_stack, rela_stack_top); + break; + case R_LARCH_SOP_SL: + err = rela_stack_push(opr1 << opr2, rela_stack, rela_stack_top); + break; + case R_LARCH_SOP_SR: + err = rela_stack_push(opr1 >> opr2, rela_stack, rela_stack_top); + break; + case R_LARCH_SOP_IF_ELSE: + err = rela_stack_push(opr1 ? opr2 : opr3, rela_stack, rela_stack_top); + break; + default: + pr_err("%s: Unsupport relocation type %u\n", mod->name, type); + return -EINVAL; + } + + return err; +} + +static int apply_r_larch_sop_imm_field(struct module *mod, u32 *location, Elf_Addr v, + s64 *rela_stack, size_t *rela_stack_top, unsigned int type) +{ + int err = 0; + s64 opr1; + union loongarch_instruction *insn = (union loongarch_instruction *)location; + + err = rela_stack_pop(&opr1, rela_stack, rela_stack_top); + if (err) + return err; + + switch (type) { + case R_LARCH_SOP_POP_32_U_10_12: + if (!unsigned_imm_check(opr1, 12)) + goto overflow; + + /* (*(uint32_t *) PC) [21 ... 10] = opr [11 ... 0] */ + insn->reg2i12_format.immediate = opr1 & 0xfff; + return 0; + case R_LARCH_SOP_POP_32_S_10_12: + if (!signed_imm_check(opr1, 12)) + goto overflow; + + insn->reg2i12_format.immediate = opr1 & 0xfff; + return 0; + case R_LARCH_SOP_POP_32_S_10_16: + if (!signed_imm_check(opr1, 16)) + goto overflow; + + insn->reg2i16_format.immediate = opr1 & 0xffff; + return 0; + case R_LARCH_SOP_POP_32_S_10_16_S2: + if (opr1 % 4) + goto unaligned; + + if (!signed_imm_check(opr1, 18)) + goto overflow; + + insn->reg2i16_format.immediate = (opr1 >> 2) & 0xffff; + return 0; + case R_LARCH_SOP_POP_32_S_5_20: + if (!signed_imm_check(opr1, 20)) + goto overflow; + + insn->reg1i20_format.immediate = (opr1) & 0xfffff; + return 0; + case R_LARCH_SOP_POP_32_S_0_5_10_16_S2: + if (opr1 % 4) + goto unaligned; + + if (!signed_imm_check(opr1, 23)) + goto overflow; + + opr1 >>= 2; + insn->reg1i21_format.immediate_l = opr1 & 0xffff; + insn->reg1i21_format.immediate_h = (opr1 >> 16) & 0x1f; + return 0; + case R_LARCH_SOP_POP_32_S_0_10_10_16_S2: + if (opr1 % 4) + goto unaligned; + + if (!signed_imm_check(opr1, 28)) + goto overflow; + + opr1 >>= 2; + insn->reg0i26_format.immediate_l = opr1 & 0xffff; + insn->reg0i26_format.immediate_h = (opr1 >> 16) & 0x3ff; + return 0; + case R_LARCH_SOP_POP_32_U: + if (!unsigned_imm_check(opr1, 32)) + goto overflow; + + /* (*(uint32_t *) PC) = opr */ + *location = (u32)opr1; + return 0; + default: + pr_err("%s: Unsupport relocation type %u\n", mod->name, type); + return -EINVAL; + } + +overflow: + pr_err("module %s: opr1 = 0x%llx overflow! dangerous %s (%u) relocation\n", + mod->name, opr1, __func__, type); + return -ENOEXEC; + +unaligned: + pr_err("module %s: opr1 = 0x%llx unaligned! dangerous %s (%u) relocation\n", + mod->name, opr1, __func__, type); + return -ENOEXEC; +} + +static int apply_r_larch_add_sub(struct module *mod, u32 *location, Elf_Addr v, + s64 *rela_stack, size_t *rela_stack_top, unsigned int type) +{ + switch (type) { + case R_LARCH_ADD32: + *(s32 *)location += v; + return 0; + case R_LARCH_ADD64: + *(s64 *)location += v; + return 0; + case R_LARCH_SUB32: + *(s32 *)location -= v; + return 0; + case R_LARCH_SUB64: + *(s64 *)location -= v; + return 0; + default: + pr_err("%s: Unsupport relocation type %u\n", mod->name, type); + return -EINVAL; + } +} + +/* + * reloc_handlers_rela() - Apply a particular relocation to a module + * @mod: the module to apply the reloc to + * @location: the address at which the reloc is to be applied + * @v: the value of the reloc, with addend for RELA-style + * @rela_stack: the stack used for store relocation info, LOCAL to THIS module + * @rela_stac_top: where the stack operation(pop/push) applies to + * + * Return: 0 upon success, else -ERRNO + */ +typedef int (*reloc_rela_handler)(struct module *mod, u32 *location, Elf_Addr v, + s64 *rela_stack, size_t *rela_stack_top, unsigned int type); + +/* The handlers for known reloc types */ +static reloc_rela_handler reloc_rela_handlers[] = { + [R_LARCH_NONE ... R_LARCH_SUB64] = apply_r_larch_error, + + [R_LARCH_NONE] = apply_r_larch_none, + [R_LARCH_32] = apply_r_larch_32, + [R_LARCH_64] = apply_r_larch_64, + [R_LARCH_MARK_LA] = apply_r_larch_none, + [R_LARCH_MARK_PCREL] = apply_r_larch_none, + [R_LARCH_SOP_PUSH_PCREL] = apply_r_larch_sop_push_pcrel, + [R_LARCH_SOP_PUSH_ABSOLUTE] = apply_r_larch_sop_push_absolute, + [R_LARCH_SOP_PUSH_DUP] = apply_r_larch_sop_push_dup, + [R_LARCH_SOP_PUSH_PLT_PCREL] = apply_r_larch_sop_push_plt_pcrel, + [R_LARCH_SOP_SUB ... R_LARCH_SOP_IF_ELSE] = apply_r_larch_sop, + [R_LARCH_SOP_POP_32_S_10_5 ... R_LARCH_SOP_POP_32_U] = apply_r_larch_sop_imm_field, + [R_LARCH_ADD32 ... R_LARCH_SUB64] = apply_r_larch_add_sub, +}; + +int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, + unsigned int symindex, unsigned int relsec, + struct module *mod) +{ + int i, err; + unsigned int type; + s64 rela_stack[RELA_STACK_DEPTH]; + size_t rela_stack_top = 0; + reloc_rela_handler handler; + void *location; + Elf_Addr v; + Elf_Sym *sym; + Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr; + + pr_debug("%s: Applying relocate section %u to %u\n", __func__, relsec, + sechdrs[relsec].sh_info); + + rela_stack_top = 0; + for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { + /* This is where to make the change */ + location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + rel[i].r_offset; + /* This is the symbol it is referring to */ + sym = (Elf_Sym *)sechdrs[symindex].sh_addr + ELF_R_SYM(rel[i].r_info); + if (IS_ERR_VALUE(sym->st_value)) { + /* Ignore unresolved weak symbol */ + if (ELF_ST_BIND(sym->st_info) == STB_WEAK) + continue; + pr_warn("%s: Unknown symbol %s\n", mod->name, strtab + sym->st_name); + return -ENOENT; + } + + type = ELF_R_TYPE(rel[i].r_info); + + if (type < ARRAY_SIZE(reloc_rela_handlers)) + handler = reloc_rela_handlers[type]; + else + handler = NULL; + + if (!handler) { + pr_err("%s: Unknown relocation type %u\n", mod->name, type); + return -EINVAL; + } + + pr_debug("type %d st_value %llx r_addend %llx loc %llx\n", + (int)ELF_R_TYPE(rel[i].r_info), + sym->st_value, rel[i].r_addend, (u64)location); + + v = sym->st_value + rel[i].r_addend; + err = handler(mod, location, v, rela_stack, &rela_stack_top, type); + if (err) + return err; + } + + return 0; +} + +void *module_alloc(unsigned long size) +{ + return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, + GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE, __builtin_return_address(0)); +} |