diff options
Diffstat (limited to 'arch/hexagon/kernel/module.c')
| -rw-r--r-- | arch/hexagon/kernel/module.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/hexagon/kernel/module.c b/arch/hexagon/kernel/module.c new file mode 100644 index 000000000..cb3bf19b0 --- /dev/null +++ b/arch/hexagon/kernel/module.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Kernel module loader for Hexagon + * + * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. + */ + +#include <asm/module.h> +#include <linux/elf.h> +#include <linux/module.h> +#include <linux/moduleloader.h> +#include <linux/vmalloc.h> + +#if 0 +#define DEBUGP printk +#else +#define DEBUGP(fmt , ...) +#endif + +/* + * module_frob_arch_sections - tweak got/plt sections. + * @hdr - pointer to elf header + * @sechdrs - pointer to elf load section headers + * @secstrings - symbol names + * @mod - pointer to module + */ +int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, + char *secstrings, + struct module *mod) +{ + unsigned int i; + int found = 0; + + /* Look for .plt and/or .got.plt and/or .init.plt sections */ + for (i = 0; i < hdr->e_shnum; i++) { + DEBUGP("Section %d is %s\n", i, + secstrings + sechdrs[i].sh_name); + if (strcmp(secstrings + sechdrs[i].sh_name, ".plt") == 0) + found = i+1; + if (strcmp(secstrings + sechdrs[i].sh_name, ".got.plt") == 0) + found = i+1; + if (strcmp(secstrings + sechdrs[i].sh_name, ".rela.plt") == 0) + found = i+1; + } + + /* At this time, we don't support modules comiled with -shared */ + if (found) { + printk(KERN_WARNING + "Module '%s' contains unexpected .plt/.got sections.\n", + mod->name); + /* return -ENOEXEC; */ + } + + return 0; +} + +/* + * apply_relocate_add - perform rela relocations. + * @sechdrs - pointer to section headers + * @strtab - some sort of start address? + * @symindex - symbol index offset or something? + * @relsec - address to relocate to? + * @module - pointer to module + * + * Perform rela relocations. + */ +int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, + unsigned int symindex, unsigned int relsec, + struct module *module) +{ + unsigned int i; + Elf32_Sym *sym; + uint32_t *location; + uint32_t value; + unsigned int nrelocs = sechdrs[relsec].sh_size / sizeof(Elf32_Rela); + Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr; + Elf32_Word sym_info = sechdrs[relsec].sh_info; + Elf32_Sym *sym_base = (Elf32_Sym *) sechdrs[symindex].sh_addr; + void *loc_base = (void *) sechdrs[sym_info].sh_addr; + + DEBUGP("Applying relocations in section %u to section %u base=%p\n", + relsec, sym_info, loc_base); + + for (i = 0; i < nrelocs; i++) { + + /* Symbol to relocate */ + sym = sym_base + ELF32_R_SYM(rela[i].r_info); + + /* Where to make the change */ + location = loc_base + rela[i].r_offset; + + /* `Everything is relative'. */ + value = sym->st_value + rela[i].r_addend; + + DEBUGP("%d: value=%08x loc=%p reloc=%d symbol=%s\n", + i, value, location, ELF32_R_TYPE(rela[i].r_info), + sym->st_name ? + &strtab[sym->st_name] : "(anonymous)"); + + switch (ELF32_R_TYPE(rela[i].r_info)) { + case R_HEXAGON_B22_PCREL: { + int dist = (int)(value - (uint32_t)location); + if ((dist < -0x00800000) || + (dist >= 0x00800000)) { + printk(KERN_ERR + "%s: %s: %08x=%08x-%08x %s\n", + module->name, + "R_HEXAGON_B22_PCREL reloc out of range", + dist, value, (uint32_t)location, + sym->st_name ? + &strtab[sym->st_name] : "(anonymous)"); + return -ENOEXEC; + } + DEBUGP("B22_PCREL contents: %08X.\n", *location); + *location &= ~0x01ff3fff; + *location |= 0x00003fff & dist; + *location |= 0x01ff0000 & (dist<<2); + DEBUGP("Contents after reloc: %08x\n", *location); + break; + } + case R_HEXAGON_HI16: + value = (value>>16) & 0xffff; + fallthrough; + case R_HEXAGON_LO16: + *location &= ~0x00c03fff; + *location |= value & 0x3fff; + *location |= (value & 0xc000) << 8; + break; + case R_HEXAGON_32: + *location = value; + break; + case R_HEXAGON_32_PCREL: + *location = value - (uint32_t)location; + break; + case R_HEXAGON_PLT_B22_PCREL: + case R_HEXAGON_GOTOFF_LO16: + case R_HEXAGON_GOTOFF_HI16: + printk(KERN_ERR "%s: GOT/PLT relocations unsupported\n", + module->name); + return -ENOEXEC; + default: + printk(KERN_ERR "%s: unknown relocation: %u\n", + module->name, + ELF32_R_TYPE(rela[i].r_info)); + return -ENOEXEC; + } + } + return 0; +} |