| /* |
| * 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. |
| * |
| * Copyright (C) 2017 Zihao Yu |
| */ |
| |
| #include <linux/elf.h> |
| #include <linux/err.h> |
| #include <linux/errno.h> |
| #include <linux/moduleloader.h> |
| |
| static int apply_r_riscv_32_rela(struct module *me, u32 *location, Elf_Addr v) |
| { |
| if (v != (u32)v) { |
| pr_err("%s: value %016llx out of range for 32-bit field\n", |
| me->name, (long long)v); |
| return -EINVAL; |
| } |
| *location = v; |
| return 0; |
| } |
| |
| static int apply_r_riscv_64_rela(struct module *me, u32 *location, Elf_Addr v) |
| { |
| *(u64 *)location = v; |
| return 0; |
| } |
| |
| static int apply_r_riscv_branch_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| ptrdiff_t offset = (void *)v - (void *)location; |
| u32 imm12 = (offset & 0x1000) << (31 - 12); |
| u32 imm11 = (offset & 0x800) >> (11 - 7); |
| u32 imm10_5 = (offset & 0x7e0) << (30 - 10); |
| u32 imm4_1 = (offset & 0x1e) << (11 - 4); |
| |
| *location = (*location & 0x1fff07f) | imm12 | imm11 | imm10_5 | imm4_1; |
| return 0; |
| } |
| |
| static int apply_r_riscv_jal_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| ptrdiff_t offset = (void *)v - (void *)location; |
| u32 imm20 = (offset & 0x100000) << (31 - 20); |
| u32 imm19_12 = (offset & 0xff000); |
| u32 imm11 = (offset & 0x800) << (20 - 11); |
| u32 imm10_1 = (offset & 0x7fe) << (30 - 10); |
| |
| *location = (*location & 0xfff) | imm20 | imm19_12 | imm11 | imm10_1; |
| return 0; |
| } |
| |
| static int apply_r_riscv_rcv_branch_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| ptrdiff_t offset = (void *)v - (void *)location; |
| u16 imm8 = (offset & 0x100) << (12 - 8); |
| u16 imm7_6 = (offset & 0xc0) >> (6 - 5); |
| u16 imm5 = (offset & 0x20) >> (5 - 2); |
| u16 imm4_3 = (offset & 0x18) << (12 - 5); |
| u16 imm2_1 = (offset & 0x6) << (12 - 10); |
| |
| *(u16 *)location = (*(u16 *)location & 0xe383) | |
| imm8 | imm7_6 | imm5 | imm4_3 | imm2_1; |
| return 0; |
| } |
| |
| static int apply_r_riscv_rvc_jump_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| ptrdiff_t offset = (void *)v - (void *)location; |
| u16 imm11 = (offset & 0x800) << (12 - 11); |
| u16 imm10 = (offset & 0x400) >> (10 - 8); |
| u16 imm9_8 = (offset & 0x300) << (12 - 11); |
| u16 imm7 = (offset & 0x80) >> (7 - 6); |
| u16 imm6 = (offset & 0x40) << (12 - 11); |
| u16 imm5 = (offset & 0x20) >> (5 - 2); |
| u16 imm4 = (offset & 0x10) << (12 - 5); |
| u16 imm3_1 = (offset & 0xe) << (12 - 10); |
| |
| *(u16 *)location = (*(u16 *)location & 0xe003) | |
| imm11 | imm10 | imm9_8 | imm7 | imm6 | imm5 | imm4 | imm3_1; |
| return 0; |
| } |
| |
| static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| ptrdiff_t offset = (void *)v - (void *)location; |
| s32 hi20; |
| |
| if (offset != (s32)offset) { |
| pr_err( |
| "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n", |
| me->name, (long long)v, location); |
| return -EINVAL; |
| } |
| |
| hi20 = (offset + 0x800) & 0xfffff000; |
| *location = (*location & 0xfff) | hi20; |
| return 0; |
| } |
| |
| static int apply_r_riscv_pcrel_lo12_i_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| /* |
| * v is the lo12 value to fill. It is calculated before calling this |
| * handler. |
| */ |
| *location = (*location & 0xfffff) | ((v & 0xfff) << 20); |
| return 0; |
| } |
| |
| static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| /* |
| * v is the lo12 value to fill. It is calculated before calling this |
| * handler. |
| */ |
| u32 imm11_5 = (v & 0xfe0) << (31 - 11); |
| u32 imm4_0 = (v & 0x1f) << (11 - 4); |
| |
| *location = (*location & 0x1fff07f) | imm11_5 | imm4_0; |
| return 0; |
| } |
| |
| static int apply_r_riscv_hi20_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| s32 hi20; |
| |
| if (IS_ENABLED(CMODEL_MEDLOW)) { |
| pr_err( |
| "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n", |
| me->name, (long long)v, location); |
| return -EINVAL; |
| } |
| |
| hi20 = ((s32)v + 0x800) & 0xfffff000; |
| *location = (*location & 0xfff) | hi20; |
| return 0; |
| } |
| |
| static int apply_r_riscv_lo12_i_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| /* Skip medlow checking because of filtering by HI20 already */ |
| s32 hi20 = ((s32)v + 0x800) & 0xfffff000; |
| s32 lo12 = ((s32)v - hi20); |
| *location = (*location & 0xfffff) | ((lo12 & 0xfff) << 20); |
| return 0; |
| } |
| |
| static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| /* Skip medlow checking because of filtering by HI20 already */ |
| s32 hi20 = ((s32)v + 0x800) & 0xfffff000; |
| s32 lo12 = ((s32)v - hi20); |
| u32 imm11_5 = (lo12 & 0xfe0) << (31 - 11); |
| u32 imm4_0 = (lo12 & 0x1f) << (11 - 4); |
| *location = (*location & 0x1fff07f) | imm11_5 | imm4_0; |
| return 0; |
| } |
| |
| static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| ptrdiff_t offset = (void *)v - (void *)location; |
| s32 hi20; |
| |
| /* Always emit the got entry */ |
| if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) { |
| offset = module_emit_got_entry(me, v); |
| offset = (void *)offset - (void *)location; |
| } else { |
| pr_err( |
| "%s: can not generate the GOT entry for symbol = %016llx from PC = %p\n", |
| me->name, (long long)v, location); |
| return -EINVAL; |
| } |
| |
| hi20 = (offset + 0x800) & 0xfffff000; |
| *location = (*location & 0xfff) | hi20; |
| return 0; |
| } |
| |
| static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| ptrdiff_t offset = (void *)v - (void *)location; |
| s32 fill_v = offset; |
| u32 hi20, lo12; |
| |
| if (offset != fill_v) { |
| /* Only emit the plt entry if offset over 32-bit range */ |
| if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) { |
| offset = module_emit_plt_entry(me, v); |
| offset = (void *)offset - (void *)location; |
| } else { |
| pr_err( |
| "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n", |
| me->name, (long long)v, location); |
| return -EINVAL; |
| } |
| } |
| |
| hi20 = (offset + 0x800) & 0xfffff000; |
| lo12 = (offset - hi20) & 0xfff; |
| *location = (*location & 0xfff) | hi20; |
| *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20); |
| return 0; |
| } |
| |
| static int apply_r_riscv_call_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| ptrdiff_t offset = (void *)v - (void *)location; |
| s32 fill_v = offset; |
| u32 hi20, lo12; |
| |
| if (offset != fill_v) { |
| pr_err( |
| "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n", |
| me->name, (long long)v, location); |
| return -EINVAL; |
| } |
| |
| hi20 = (offset + 0x800) & 0xfffff000; |
| lo12 = (offset - hi20) & 0xfff; |
| *location = (*location & 0xfff) | hi20; |
| *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20); |
| return 0; |
| } |
| |
| static int apply_r_riscv_relax_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| return 0; |
| } |
| |
| static int apply_r_riscv_align_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| pr_err( |
| "%s: The unexpected relocation type 'R_RISCV_ALIGN' from PC = %p\n", |
| me->name, location); |
| return -EINVAL; |
| } |
| |
| static int apply_r_riscv_add32_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| *(u32 *)location += (u32)v; |
| return 0; |
| } |
| |
| static int apply_r_riscv_sub32_rela(struct module *me, u32 *location, |
| Elf_Addr v) |
| { |
| *(u32 *)location -= (u32)v; |
| return 0; |
| } |
| |
| static int (*reloc_handlers_rela[]) (struct module *me, u32 *location, |
| Elf_Addr v) = { |
| [R_RISCV_32] = apply_r_riscv_32_rela, |
| [R_RISCV_64] = apply_r_riscv_64_rela, |
| [R_RISCV_BRANCH] = apply_r_riscv_branch_rela, |
| [R_RISCV_JAL] = apply_r_riscv_jal_rela, |
| [R_RISCV_RVC_BRANCH] = apply_r_riscv_rcv_branch_rela, |
| [R_RISCV_RVC_JUMP] = apply_r_riscv_rvc_jump_rela, |
| [R_RISCV_PCREL_HI20] = apply_r_riscv_pcrel_hi20_rela, |
| [R_RISCV_PCREL_LO12_I] = apply_r_riscv_pcrel_lo12_i_rela, |
| [R_RISCV_PCREL_LO12_S] = apply_r_riscv_pcrel_lo12_s_rela, |
| [R_RISCV_HI20] = apply_r_riscv_hi20_rela, |
| [R_RISCV_LO12_I] = apply_r_riscv_lo12_i_rela, |
| [R_RISCV_LO12_S] = apply_r_riscv_lo12_s_rela, |
| [R_RISCV_GOT_HI20] = apply_r_riscv_got_hi20_rela, |
| [R_RISCV_CALL_PLT] = apply_r_riscv_call_plt_rela, |
| [R_RISCV_CALL] = apply_r_riscv_call_rela, |
| [R_RISCV_RELAX] = apply_r_riscv_relax_rela, |
| [R_RISCV_ALIGN] = apply_r_riscv_align_rela, |
| [R_RISCV_ADD32] = apply_r_riscv_add32_rela, |
| [R_RISCV_SUB32] = apply_r_riscv_sub32_rela, |
| }; |
| |
| int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, |
| unsigned int symindex, unsigned int relsec, |
| struct module *me) |
| { |
| Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr; |
| int (*handler)(struct module *me, u32 *location, Elf_Addr v); |
| Elf_Sym *sym; |
| u32 *location; |
| unsigned int i, type; |
| Elf_Addr v; |
| int res; |
| |
| pr_debug("Applying relocate section %u to %u\n", relsec, |
| sechdrs[relsec].sh_info); |
| |
| 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_RISCV_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_warning("%s: Unknown symbol %s\n", |
| me->name, strtab + sym->st_name); |
| return -ENOENT; |
| } |
| |
| type = ELF_RISCV_R_TYPE(rel[i].r_info); |
| |
| if (type < ARRAY_SIZE(reloc_handlers_rela)) |
| handler = reloc_handlers_rela[type]; |
| else |
| handler = NULL; |
| |
| if (!handler) { |
| pr_err("%s: Unknown relocation type %u\n", |
| me->name, type); |
| return -EINVAL; |
| } |
| |
| v = sym->st_value + rel[i].r_addend; |
| |
| if (type == R_RISCV_PCREL_LO12_I || type == R_RISCV_PCREL_LO12_S) { |
| unsigned int j; |
| |
| for (j = 0; j < sechdrs[relsec].sh_size / sizeof(*rel); j++) { |
| unsigned long hi20_loc = |
| sechdrs[sechdrs[relsec].sh_info].sh_addr |
| + rel[j].r_offset; |
| u32 hi20_type = ELF_RISCV_R_TYPE(rel[j].r_info); |
| |
| /* Find the corresponding HI20 relocation entry */ |
| if (hi20_loc == sym->st_value |
| && (hi20_type == R_RISCV_PCREL_HI20 |
| || hi20_type == R_RISCV_GOT_HI20)) { |
| s32 hi20, lo12; |
| Elf_Sym *hi20_sym = |
| (Elf_Sym *)sechdrs[symindex].sh_addr |
| + ELF_RISCV_R_SYM(rel[j].r_info); |
| unsigned long hi20_sym_val = |
| hi20_sym->st_value |
| + rel[j].r_addend; |
| |
| /* Calculate lo12 */ |
| size_t offset = hi20_sym_val - hi20_loc; |
| if (IS_ENABLED(CONFIG_MODULE_SECTIONS) |
| && hi20_type == R_RISCV_GOT_HI20) { |
| offset = module_emit_got_entry( |
| me, hi20_sym_val); |
| offset = offset - hi20_loc; |
| } |
| hi20 = (offset + 0x800) & 0xfffff000; |
| lo12 = offset - hi20; |
| v = lo12; |
| |
| break; |
| } |
| } |
| if (j == sechdrs[relsec].sh_size / sizeof(*rel)) { |
| pr_err( |
| "%s: Can not find HI20 relocation information\n", |
| me->name); |
| return -EINVAL; |
| } |
| } |
| |
| res = handler(me, location, v); |
| if (res) |
| return res; |
| } |
| |
| return 0; |
| } |