/* * Kernel module loader for Hexagon * * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and * only version 2 as published by the Free Software Foundation. * * 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA. */ #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; }