diff options
Diffstat (limited to 'arch/arm/kernel/module.c')
| -rw-r--r-- | arch/arm/kernel/module.c | 412 |
1 files changed, 412 insertions, 0 deletions
diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c new file mode 100644 index 000000000..3ff571c2c --- /dev/null +++ b/arch/arm/kernel/module.c @@ -0,0 +1,412 @@ +/* + * linux/arch/arm/kernel/module.c + * + * Copyright (C) 2002 Russell King. + * Modified for nommu by Hyok S. Choi + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Module allocation method suggested by Andi Kleen. + */ +#include <linux/module.h> +#include <linux/moduleloader.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/elf.h> +#include <linux/vmalloc.h> +#include <linux/fs.h> +#include <linux/string.h> +#include <linux/gfp.h> + +#include <asm/pgtable.h> +#include <asm/sections.h> +#include <asm/smp_plat.h> +#include <asm/unwind.h> +#include <asm/opcodes.h> + +#ifdef CONFIG_XIP_KERNEL +/* + * The XIP kernel text is mapped in the module area for modules and + * some other stuff to work without any indirect relocations. + * MODULES_VADDR is redefined here and not in asm/memory.h to avoid + * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off. + */ +#undef MODULES_VADDR +#define MODULES_VADDR (((unsigned long)_exiprom + ~PMD_MASK) & PMD_MASK) +#endif + +#ifdef CONFIG_MMU +void *module_alloc(unsigned long size) +{ + gfp_t gfp_mask = GFP_KERNEL; + void *p; + + /* Silence the initial allocation */ + if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS)) + gfp_mask |= __GFP_NOWARN; + + p = __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, + gfp_mask, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, + __builtin_return_address(0)); + if (!IS_ENABLED(CONFIG_ARM_MODULE_PLTS) || p) + return p; + return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, + GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, + __builtin_return_address(0)); +} +#endif + +int +apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, + unsigned int relindex, struct module *module) +{ + Elf32_Shdr *symsec = sechdrs + symindex; + Elf32_Shdr *relsec = sechdrs + relindex; + Elf32_Shdr *dstsec = sechdrs + relsec->sh_info; + Elf32_Rel *rel = (void *)relsec->sh_addr; + unsigned int i; + + for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) { + unsigned long loc; + Elf32_Sym *sym; + const char *symname; + s32 offset; + u32 tmp; +#ifdef CONFIG_THUMB2_KERNEL + u32 upper, lower, sign, j1, j2; +#endif + + offset = ELF32_R_SYM(rel->r_info); + if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) { + pr_err("%s: section %u reloc %u: bad relocation sym offset\n", + module->name, relindex, i); + return -ENOEXEC; + } + + sym = ((Elf32_Sym *)symsec->sh_addr) + offset; + symname = strtab + sym->st_name; + + if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) { + pr_err("%s: section %u reloc %u sym '%s': out of bounds relocation, offset %d size %u\n", + module->name, relindex, i, symname, + rel->r_offset, dstsec->sh_size); + return -ENOEXEC; + } + + loc = dstsec->sh_addr + rel->r_offset; + + switch (ELF32_R_TYPE(rel->r_info)) { + case R_ARM_NONE: + /* ignore */ + break; + + case R_ARM_ABS32: + case R_ARM_TARGET1: + *(u32 *)loc += sym->st_value; + break; + + case R_ARM_PC24: + case R_ARM_CALL: + case R_ARM_JUMP24: + if (sym->st_value & 3) { + pr_err("%s: section %u reloc %u sym '%s': unsupported interworking call (ARM -> Thumb)\n", + module->name, relindex, i, symname); + return -ENOEXEC; + } + + offset = __mem_to_opcode_arm(*(u32 *)loc); + offset = (offset & 0x00ffffff) << 2; + if (offset & 0x02000000) + offset -= 0x04000000; + + offset += sym->st_value - loc; + + /* + * Route through a PLT entry if 'offset' exceeds the + * supported range. Note that 'offset + loc + 8' + * contains the absolute jump target, i.e., + * @sym + addend, corrected for the +8 PC bias. + */ + if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS) && + (offset <= (s32)0xfe000000 || + offset >= (s32)0x02000000)) + offset = get_module_plt(module, loc, + offset + loc + 8) + - loc - 8; + + if (offset <= (s32)0xfe000000 || + offset >= (s32)0x02000000) { + pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n", + module->name, relindex, i, symname, + ELF32_R_TYPE(rel->r_info), loc, + sym->st_value); + return -ENOEXEC; + } + + offset >>= 2; + offset &= 0x00ffffff; + + *(u32 *)loc &= __opcode_to_mem_arm(0xff000000); + *(u32 *)loc |= __opcode_to_mem_arm(offset); + break; + + case R_ARM_V4BX: + /* Preserve Rm and the condition code. Alter + * other bits to re-code instruction as + * MOV PC,Rm. + */ + *(u32 *)loc &= __opcode_to_mem_arm(0xf000000f); + *(u32 *)loc |= __opcode_to_mem_arm(0x01a0f000); + break; + + case R_ARM_PREL31: + offset = (*(s32 *)loc << 1) >> 1; /* sign extend */ + offset += sym->st_value - loc; + if (offset >= 0x40000000 || offset < -0x40000000) { + pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n", + module->name, relindex, i, symname, + ELF32_R_TYPE(rel->r_info), loc, + sym->st_value); + return -ENOEXEC; + } + *(u32 *)loc &= 0x80000000; + *(u32 *)loc |= offset & 0x7fffffff; + break; + + case R_ARM_MOVW_ABS_NC: + case R_ARM_MOVT_ABS: + offset = tmp = __mem_to_opcode_arm(*(u32 *)loc); + offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff); + offset = (offset ^ 0x8000) - 0x8000; + + offset += sym->st_value; + if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS) + offset >>= 16; + + tmp &= 0xfff0f000; + tmp |= ((offset & 0xf000) << 4) | + (offset & 0x0fff); + + *(u32 *)loc = __opcode_to_mem_arm(tmp); + break; + +#ifdef CONFIG_THUMB2_KERNEL + case R_ARM_THM_CALL: + case R_ARM_THM_JUMP24: + /* + * For function symbols, only Thumb addresses are + * allowed (no interworking). + * + * For non-function symbols, the destination + * has no specific ARM/Thumb disposition, so + * the branch is resolved under the assumption + * that interworking is not required. + */ + if (ELF32_ST_TYPE(sym->st_info) == STT_FUNC && + !(sym->st_value & 1)) { + pr_err("%s: section %u reloc %u sym '%s': unsupported interworking call (Thumb -> ARM)\n", + module->name, relindex, i, symname); + return -ENOEXEC; + } + + upper = __mem_to_opcode_thumb16(*(u16 *)loc); + lower = __mem_to_opcode_thumb16(*(u16 *)(loc + 2)); + + /* + * 25 bit signed address range (Thumb-2 BL and B.W + * instructions): + * S:I1:I2:imm10:imm11:0 + * where: + * S = upper[10] = offset[24] + * I1 = ~(J1 ^ S) = offset[23] + * I2 = ~(J2 ^ S) = offset[22] + * imm10 = upper[9:0] = offset[21:12] + * imm11 = lower[10:0] = offset[11:1] + * J1 = lower[13] + * J2 = lower[11] + */ + sign = (upper >> 10) & 1; + j1 = (lower >> 13) & 1; + j2 = (lower >> 11) & 1; + offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) | + ((~(j2 ^ sign) & 1) << 22) | + ((upper & 0x03ff) << 12) | + ((lower & 0x07ff) << 1); + if (offset & 0x01000000) + offset -= 0x02000000; + offset += sym->st_value - loc; + + /* + * Route through a PLT entry if 'offset' exceeds the + * supported range. + */ + if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS) && + (offset <= (s32)0xff000000 || + offset >= (s32)0x01000000)) + offset = get_module_plt(module, loc, + offset + loc + 4) + - loc - 4; + + if (offset <= (s32)0xff000000 || + offset >= (s32)0x01000000) { + pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n", + module->name, relindex, i, symname, + ELF32_R_TYPE(rel->r_info), loc, + sym->st_value); + return -ENOEXEC; + } + + sign = (offset >> 24) & 1; + j1 = sign ^ (~(offset >> 23) & 1); + j2 = sign ^ (~(offset >> 22) & 1); + upper = (u16)((upper & 0xf800) | (sign << 10) | + ((offset >> 12) & 0x03ff)); + lower = (u16)((lower & 0xd000) | + (j1 << 13) | (j2 << 11) | + ((offset >> 1) & 0x07ff)); + + *(u16 *)loc = __opcode_to_mem_thumb16(upper); + *(u16 *)(loc + 2) = __opcode_to_mem_thumb16(lower); + break; + + case R_ARM_THM_MOVW_ABS_NC: + case R_ARM_THM_MOVT_ABS: + upper = __mem_to_opcode_thumb16(*(u16 *)loc); + lower = __mem_to_opcode_thumb16(*(u16 *)(loc + 2)); + + /* + * MOVT/MOVW instructions encoding in Thumb-2: + * + * i = upper[10] + * imm4 = upper[3:0] + * imm3 = lower[14:12] + * imm8 = lower[7:0] + * + * imm16 = imm4:i:imm3:imm8 + */ + offset = ((upper & 0x000f) << 12) | + ((upper & 0x0400) << 1) | + ((lower & 0x7000) >> 4) | (lower & 0x00ff); + offset = (offset ^ 0x8000) - 0x8000; + offset += sym->st_value; + + if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS) + offset >>= 16; + + upper = (u16)((upper & 0xfbf0) | + ((offset & 0xf000) >> 12) | + ((offset & 0x0800) >> 1)); + lower = (u16)((lower & 0x8f00) | + ((offset & 0x0700) << 4) | + (offset & 0x00ff)); + *(u16 *)loc = __opcode_to_mem_thumb16(upper); + *(u16 *)(loc + 2) = __opcode_to_mem_thumb16(lower); + break; +#endif + + default: + pr_err("%s: unknown relocation: %u\n", + module->name, ELF32_R_TYPE(rel->r_info)); + return -ENOEXEC; + } + } + return 0; +} + +struct mod_unwind_map { + const Elf_Shdr *unw_sec; + const Elf_Shdr *txt_sec; +}; + +static const Elf_Shdr *find_mod_section(const Elf32_Ehdr *hdr, + const Elf_Shdr *sechdrs, const char *name) +{ + const Elf_Shdr *s, *se; + const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; + + for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) + if (strcmp(name, secstrs + s->sh_name) == 0) + return s; + + return NULL; +} + +extern void fixup_pv_table(const void *, unsigned long); +extern void fixup_smp(const void *, unsigned long); + +int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, + struct module *mod) +{ + const Elf_Shdr *s = NULL; +#ifdef CONFIG_ARM_UNWIND + const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; + const Elf_Shdr *sechdrs_end = sechdrs + hdr->e_shnum; + struct mod_unwind_map maps[ARM_SEC_MAX]; + int i; + + memset(maps, 0, sizeof(maps)); + + for (s = sechdrs; s < sechdrs_end; s++) { + const char *secname = secstrs + s->sh_name; + + if (!(s->sh_flags & SHF_ALLOC)) + continue; + + if (strcmp(".ARM.exidx.init.text", secname) == 0) + maps[ARM_SEC_INIT].unw_sec = s; + else if (strcmp(".ARM.exidx", secname) == 0) + maps[ARM_SEC_CORE].unw_sec = s; + else if (strcmp(".ARM.exidx.exit.text", secname) == 0) + maps[ARM_SEC_EXIT].unw_sec = s; + else if (strcmp(".ARM.exidx.text.unlikely", secname) == 0) + maps[ARM_SEC_UNLIKELY].unw_sec = s; + else if (strcmp(".ARM.exidx.text.hot", secname) == 0) + maps[ARM_SEC_HOT].unw_sec = s; + else if (strcmp(".init.text", secname) == 0) + maps[ARM_SEC_INIT].txt_sec = s; + else if (strcmp(".text", secname) == 0) + maps[ARM_SEC_CORE].txt_sec = s; + else if (strcmp(".exit.text", secname) == 0) + maps[ARM_SEC_EXIT].txt_sec = s; + else if (strcmp(".text.unlikely", secname) == 0) + maps[ARM_SEC_UNLIKELY].txt_sec = s; + else if (strcmp(".text.hot", secname) == 0) + maps[ARM_SEC_HOT].txt_sec = s; + } + + for (i = 0; i < ARM_SEC_MAX; i++) + if (maps[i].unw_sec && maps[i].txt_sec) + mod->arch.unwind[i] = + unwind_table_add(maps[i].unw_sec->sh_addr, + maps[i].unw_sec->sh_size, + maps[i].txt_sec->sh_addr, + maps[i].txt_sec->sh_size); +#endif +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT + s = find_mod_section(hdr, sechdrs, ".pv_table"); + if (s) + fixup_pv_table((void *)s->sh_addr, s->sh_size); +#endif + s = find_mod_section(hdr, sechdrs, ".alt.smp.init"); + if (s && !is_smp()) +#ifdef CONFIG_SMP_ON_UP + fixup_smp((void *)s->sh_addr, s->sh_size); +#else + return -EINVAL; +#endif + return 0; +} + +void +module_arch_cleanup(struct module *mod) +{ +#ifdef CONFIG_ARM_UNWIND + int i; + + for (i = 0; i < ARM_SEC_MAX; i++) + if (mod->arch.unwind[i]) + unwind_table_del(mod->arch.unwind[i]); +#endif +} |