diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 61dd82709898512aac64997aad42b0f44f787063..1df6e264edd3df9bdb1ccaa22f2f5458ba0660a5 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -134,6 +134,10 @@ choice bool "medium any code model" endchoice +config MODULE_SECTIONS + bool + select HAVE_MOD_ARCH_SPECIFIC + choice prompt "Maximum Physical Memory" default MAXPHYSMEM_2GB if 32BIT @@ -144,6 +148,7 @@ choice bool "2GiB" config MAXPHYSMEM_128GB depends on 64BIT && CMODEL_MEDANY + select MODULE_SECTIONS if MODULES bool "128GiB" endchoice diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 899226e0da7d3328e152e614af3c6fa03ee8c495..76e958a5414a88f9314b7bf1298eed790c1415a2 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -59,6 +59,11 @@ endif ifeq ($(CONFIG_CMODEL_MEDANY),y) KBUILD_CFLAGS += -mcmodel=medany endif +ifeq ($(CONFIG_MODULE_SECTIONS),y) + KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/riscv/kernel/module.lds +endif + +KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-relax) # GCC versions that support the "-mstrict-align" option default to allowing # unaligned accesses. While unaligned accesses are explicitly allowed in the diff --git a/arch/riscv/configs/defconfig b/arch/riscv/configs/defconfig index 47dacf06c679f3eff22c0a6ab0f619d9b4019ab5..bca0eee733b05fc5f3217296184b57aac6f90faf 100644 --- a/arch/riscv/configs/defconfig +++ b/arch/riscv/configs/defconfig @@ -73,3 +73,5 @@ CONFIG_NFS_V4_2=y CONFIG_ROOT_NFS=y # CONFIG_RCU_TRACE is not set CONFIG_CRYPTO_USER_API_HASH=y +CONFIG_MODULES=y +CONFIG_MODULE_UNLOAD=y diff --git a/arch/riscv/include/asm/module.h b/arch/riscv/include/asm/module.h new file mode 100644 index 0000000000000000000000000000000000000000..349df33808c4231d155d2e6018e19cc4cb19cb4d --- /dev/null +++ b/arch/riscv/include/asm/module.h @@ -0,0 +1,113 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) 2017 Andes Technology Corporation */ + +#ifndef _ASM_RISCV_MODULE_H +#define _ASM_RISCV_MODULE_H + +#include + +#define MODULE_ARCH_VERMAGIC "riscv" + +u64 module_emit_got_entry(struct module *mod, u64 val); +u64 module_emit_plt_entry(struct module *mod, u64 val); + +#ifdef CONFIG_MODULE_SECTIONS +struct mod_section { + struct elf64_shdr *shdr; + int num_entries; + int max_entries; +}; + +struct mod_arch_specific { + struct mod_section got; + struct mod_section plt; + struct mod_section got_plt; +}; + +struct got_entry { + u64 symbol_addr; /* the real variable address */ +}; + +static inline struct got_entry emit_got_entry(u64 val) +{ + return (struct got_entry) {val}; +} + +static inline struct got_entry *get_got_entry(u64 val, + const struct mod_section *sec) +{ + struct got_entry *got = (struct got_entry *)sec->shdr->sh_addr; + int i; + for (i = 0; i < sec->num_entries; i++) { + if (got[i].symbol_addr == val) + return &got[i]; + } + return NULL; +} + +struct plt_entry { + /* + * Trampoline code to real target address. The return address + * should be the original (pc+4) before entring plt entry. + */ + u32 insn_auipc; /* auipc t0, 0x0 */ + u32 insn_ld; /* ld t1, 0x10(t0) */ + u32 insn_jr; /* jr t1 */ +}; + +#define OPC_AUIPC 0x0017 +#define OPC_LD 0x3003 +#define OPC_JALR 0x0067 +#define REG_T0 0x5 +#define REG_T1 0x6 + +static inline struct plt_entry emit_plt_entry(u64 val, u64 plt, u64 got_plt) +{ + /* + * U-Type encoding: + * +------------+----------+----------+ + * | imm[31:12] | rd[11:7] | opc[6:0] | + * +------------+----------+----------+ + * + * I-Type encoding: + * +------------+------------+--------+----------+----------+ + * | imm[31:20] | rs1[19:15] | funct3 | rd[11:7] | opc[6:0] | + * +------------+------------+--------+----------+----------+ + * + */ + u64 offset = got_plt - plt; + u32 hi20 = (offset + 0x800) & 0xfffff000; + u32 lo12 = (offset - hi20); + return (struct plt_entry) { + OPC_AUIPC | (REG_T0 << 7) | hi20, + OPC_LD | (lo12 << 20) | (REG_T0 << 15) | (REG_T1 << 7), + OPC_JALR | (REG_T1 << 15) + }; +} + +static inline int get_got_plt_idx(u64 val, const struct mod_section *sec) +{ + struct got_entry *got_plt = (struct got_entry *)sec->shdr->sh_addr; + int i; + for (i = 0; i < sec->num_entries; i++) { + if (got_plt[i].symbol_addr == val) + return i; + } + return -1; +} + +static inline struct plt_entry *get_plt_entry(u64 val, + const struct mod_section *sec_plt, + const struct mod_section *sec_got_plt) +{ + struct plt_entry *plt = (struct plt_entry *)sec_plt->shdr->sh_addr; + int got_plt_idx = get_got_plt_idx(val, sec_got_plt); + if (got_plt_idx >= 0) + return plt + got_plt_idx; + else + return NULL; +} + +#endif /* CONFIG_MODULE_SECTIONS */ + +#endif /* _ASM_RISCV_MODULE_H */ diff --git a/arch/riscv/include/uapi/asm/elf.h b/arch/riscv/include/uapi/asm/elf.h index a510edfa82264c6e52b1638ad1d14e7c24b313f3..5cae4c30cd8e2e2147b59285f9eccaaae7e9a789 100644 --- a/arch/riscv/include/uapi/asm/elf.h +++ b/arch/riscv/include/uapi/asm/elf.h @@ -79,5 +79,12 @@ typedef union __riscv_fp_state elf_fpregset_t; #define R_RISCV_TPREL_I 49 #define R_RISCV_TPREL_S 50 #define R_RISCV_RELAX 51 +#define R_RISCV_SUB6 52 +#define R_RISCV_SET6 53 +#define R_RISCV_SET8 54 +#define R_RISCV_SET16 55 +#define R_RISCV_SET32 56 +#define R_RISCV_32_PCREL 57 + #endif /* _UAPI_ASM_ELF_H */ diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index d7bdf888f1ca65b48dfa6dc58a5d382942bcfaf7..8586dd96c2f012ca42af358c0ab58cd2ce277322 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -34,6 +34,7 @@ CFLAGS_setup.o := -mcmodel=medany obj-$(CONFIG_SMP) += smpboot.o obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_MODULES) += module.o +obj-$(CONFIG_MODULE_SECTIONS) += module-sections.o obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o obj-$(CONFIG_DYNAMIC_FTRACE) += mcount-dyn.o diff --git a/arch/riscv/kernel/module-sections.c b/arch/riscv/kernel/module-sections.c new file mode 100644 index 0000000000000000000000000000000000000000..bbbd26e19bfddbe957c4b199dd9d5edf6b3dd327 --- /dev/null +++ b/arch/riscv/kernel/module-sections.c @@ -0,0 +1,156 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * Copyright (C) 2014-2017 Linaro Ltd. + * + * Copyright (C) 2018 Andes Technology Corporation + */ + +#include +#include +#include + +u64 module_emit_got_entry(struct module *mod, u64 val) +{ + struct mod_section *got_sec = &mod->arch.got; + int i = got_sec->num_entries; + struct got_entry *got = get_got_entry(val, got_sec); + + if (got) + return (u64)got; + + /* There is no duplicate entry, create a new one */ + got = (struct got_entry *)got_sec->shdr->sh_addr; + got[i] = emit_got_entry(val); + + got_sec->num_entries++; + BUG_ON(got_sec->num_entries > got_sec->max_entries); + + return (u64)&got[i]; +} + +u64 module_emit_plt_entry(struct module *mod, u64 val) +{ + struct mod_section *got_plt_sec = &mod->arch.got_plt; + struct got_entry *got_plt; + struct mod_section *plt_sec = &mod->arch.plt; + struct plt_entry *plt = get_plt_entry(val, plt_sec, got_plt_sec); + int i = plt_sec->num_entries; + + if (plt) + return (u64)plt; + + /* There is no duplicate entry, create a new one */ + got_plt = (struct got_entry *)got_plt_sec->shdr->sh_addr; + got_plt[i] = emit_got_entry(val); + plt = (struct plt_entry *)plt_sec->shdr->sh_addr; + plt[i] = emit_plt_entry(val, (u64)&plt[i], (u64)&got_plt[i]); + + plt_sec->num_entries++; + got_plt_sec->num_entries++; + BUG_ON(plt_sec->num_entries > plt_sec->max_entries); + + return (u64)&plt[i]; +} + +static int is_rela_equal(const Elf64_Rela *x, const Elf64_Rela *y) +{ + return x->r_info == y->r_info && x->r_addend == y->r_addend; +} + +static bool duplicate_rela(const Elf64_Rela *rela, int idx) +{ + int i; + for (i = 0; i < idx; i++) { + if (is_rela_equal(&rela[i], &rela[idx])) + return true; + } + return false; +} + +static void count_max_entries(Elf64_Rela *relas, int num, + unsigned int *plts, unsigned int *gots) +{ + unsigned int type, i; + + for (i = 0; i < num; i++) { + type = ELF64_R_TYPE(relas[i].r_info); + if (type == R_RISCV_CALL_PLT) { + if (!duplicate_rela(relas, i)) + (*plts)++; + } else if (type == R_RISCV_GOT_HI20) { + if (!duplicate_rela(relas, i)) + (*gots)++; + } + } +} + +int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, + char *secstrings, struct module *mod) +{ + unsigned int num_plts = 0; + unsigned int num_gots = 0; + int i; + + /* + * Find the empty .got and .plt sections. + */ + for (i = 0; i < ehdr->e_shnum; i++) { + if (!strcmp(secstrings + sechdrs[i].sh_name, ".plt")) + mod->arch.plt.shdr = sechdrs + i; + else if (!strcmp(secstrings + sechdrs[i].sh_name, ".got")) + mod->arch.got.shdr = sechdrs + i; + else if (!strcmp(secstrings + sechdrs[i].sh_name, ".got.plt")) + mod->arch.got_plt.shdr = sechdrs + i; + } + + if (!mod->arch.plt.shdr) { + pr_err("%s: module PLT section(s) missing\n", mod->name); + return -ENOEXEC; + } + if (!mod->arch.got.shdr) { + pr_err("%s: module GOT section(s) missing\n", mod->name); + return -ENOEXEC; + } + if (!mod->arch.got_plt.shdr) { + pr_err("%s: module GOT.PLT section(s) missing\n", mod->name); + return -ENOEXEC; + } + + /* Calculate the maxinum number of entries */ + for (i = 0; i < ehdr->e_shnum; i++) { + Elf64_Rela *relas = (void *)ehdr + sechdrs[i].sh_offset; + int num_rela = sechdrs[i].sh_size / sizeof(Elf64_Rela); + Elf64_Shdr *dst_sec = sechdrs + sechdrs[i].sh_info; + + if (sechdrs[i].sh_type != SHT_RELA) + continue; + + /* ignore relocations that operate on non-exec sections */ + if (!(dst_sec->sh_flags & SHF_EXECINSTR)) + continue; + + count_max_entries(relas, num_rela, &num_plts, &num_gots); + } + + mod->arch.plt.shdr->sh_type = SHT_NOBITS; + mod->arch.plt.shdr->sh_flags = SHF_EXECINSTR | SHF_ALLOC; + mod->arch.plt.shdr->sh_addralign = L1_CACHE_BYTES; + mod->arch.plt.shdr->sh_size = (num_plts + 1) * sizeof(struct plt_entry); + mod->arch.plt.num_entries = 0; + mod->arch.plt.max_entries = num_plts; + + mod->arch.got.shdr->sh_type = SHT_NOBITS; + mod->arch.got.shdr->sh_flags = SHF_ALLOC; + mod->arch.got.shdr->sh_addralign = L1_CACHE_BYTES; + mod->arch.got.shdr->sh_size = (num_gots + 1) * sizeof(struct got_entry); + mod->arch.got.num_entries = 0; + mod->arch.got.max_entries = num_gots; + + mod->arch.got_plt.shdr->sh_type = SHT_NOBITS; + mod->arch.got_plt.shdr->sh_flags = SHF_ALLOC; + mod->arch.got_plt.shdr->sh_addralign = L1_CACHE_BYTES; + mod->arch.got_plt.shdr->sh_size = (num_plts + 1) * sizeof(struct got_entry); + mod->arch.got_plt.num_entries = 0; + mod->arch.got_plt.max_entries = num_plts; + return 0; +} diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c index e0f05034fc218eb04b7b71c962ed610458165320..5dddba301d0a726ff78e97acca1b051c123a8bb7 100644 --- a/arch/riscv/kernel/module.c +++ b/arch/riscv/kernel/module.c @@ -49,6 +49,39 @@ static int apply_r_riscv_jal_rela(struct module *me, u32 *location, return 0; } +static int apply_r_riscv_rcv_branch_rela(struct module *me, u32 *location, + Elf_Addr v) +{ + s64 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) +{ + s64 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) { @@ -92,6 +125,67 @@ static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location, 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, 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) +{ + s64 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, 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) { @@ -99,6 +193,33 @@ static int apply_r_riscv_call_plt_rela(struct module *me, u32 *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, 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) +{ + s64 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", @@ -119,16 +240,49 @@ static int apply_r_riscv_relax_rela(struct module *me, u32 *location, 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_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, @@ -184,25 +338,38 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, u64 hi20_loc = sechdrs[sechdrs[relsec].sh_info].sh_addr + rel[j].r_offset; - /* Find the corresponding HI20 PC-relative relocation entry */ - if (hi20_loc == sym->st_value) { + 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); u64 hi20_sym_val = hi20_sym->st_value + rel[j].r_addend; + /* Calculate lo12 */ - s64 offset = hi20_sym_val - hi20_loc; - s32 hi20 = (offset + 0x800) & 0xfffff000; - s32 lo12 = offset - hi20; + u64 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 PC-relative relocation information\n", + "%s: Can not find HI20 relocation information\n", me->name); return -EINVAL; } diff --git a/arch/riscv/kernel/module.lds b/arch/riscv/kernel/module.lds new file mode 100644 index 0000000000000000000000000000000000000000..295ecfb341a29fa061e64fe48483a3dc911efab8 --- /dev/null +++ b/arch/riscv/kernel/module.lds @@ -0,0 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) 2017 Andes Technology Corporation */ + +SECTIONS { + .plt (NOLOAD) : { BYTE(0) } + .got (NOLOAD) : { BYTE(0) } + .got.plt (NOLOAD) : { BYTE(0) } +}