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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/nios2/kernel/module.c
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/*

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 * Kernel module support for Nios II.

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 *

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 * Copyright (C) 2004 Microtronix Datacom Ltd.

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 *   Written by Wentao Xu <[email protected]>

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 * Copyright (C) 2001, 2003 Rusty Russell

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 *

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 * This file is subject to the terms and conditions of the GNU General

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 * Public License.  See the file COPYING in the main directory of this

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 * archive for more details.

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 */

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#include <linux/moduleloader.h>

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#include <linux/elf.h>

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#include <linux/mm.h>

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#include <linux/slab.h>

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#include <linux/fs.h>

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#include <linux/string.h>

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#include <linux/kernel.h>

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#include <asm/cacheflush.h>

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int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,

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			unsigned int symindex, unsigned int relsec,

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			struct module *mod)

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{

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	unsigned int i;

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	Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;

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	pr_debug("Applying relocate section %u to %u\n", relsec,

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		 sechdrs[relsec].sh_info);

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	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {

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		/* This is where to make the change */

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		uint32_t word;

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		uint32_t *loc

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			= ((void *)sechdrs[sechdrs[relsec].sh_info].sh_addr

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			   + rela[i].r_offset);

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		/* This is the symbol it is referring to.  Note that all

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		   undefined symbols have been resolved.  */

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		Elf32_Sym *sym

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			= ((Elf32_Sym *)sechdrs[symindex].sh_addr

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				+ ELF32_R_SYM(rela[i].r_info));

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		uint32_t v = sym->st_value + rela[i].r_addend;

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		pr_debug("reltype %d 0x%x name:<%s>\n",

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			ELF32_R_TYPE(rela[i].r_info),

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			rela[i].r_offset, strtab + sym->st_name);

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		switch (ELF32_R_TYPE(rela[i].r_info)) {

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		case R_NIOS2_NONE:

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			break;

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		case R_NIOS2_BFD_RELOC_32:

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			*loc += v;

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			break;

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		case R_NIOS2_PCREL16:

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			v -= (uint32_t)loc + 4;

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			if ((int32_t)v > 0x7fff ||

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				(int32_t)v < -(int32_t)0x8000) {

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				pr_err("module %s: relocation overflow\n",

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					mod->name);

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				return -ENOEXEC;

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			}

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			word = *loc;

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			*loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) |

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				(word & 0x3f);

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			break;

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		case R_NIOS2_CALL26:

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			if (v & 3) {

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				pr_err("module %s: dangerous relocation\n",

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					mod->name);

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				return -ENOEXEC;

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			}

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			if ((v >> 28) != ((uint32_t)loc >> 28)) {

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				pr_err("module %s: relocation overflow\n",

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					mod->name);

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				return -ENOEXEC;

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			}

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			*loc = (*loc & 0x3f) | ((v >> 2) << 6);

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			break;

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		case R_NIOS2_HI16:

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			word = *loc;

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			*loc = ((((word >> 22) << 16) |

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				((v >> 16) & 0xffff)) << 6) | (word & 0x3f);

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			break;

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		case R_NIOS2_LO16:

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			word = *loc;

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			*loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) |

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					(word & 0x3f);

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			break;

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		case R_NIOS2_HIADJ16:

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			{

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				Elf32_Addr word2;

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				word = *loc;

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				word2 = ((v >> 16) + ((v >> 15) & 1)) & 0xffff;

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				*loc = ((((word >> 22) << 16) | word2) << 6) |

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						(word & 0x3f);

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			}

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			break;

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		default:

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			pr_err("module %s: Unknown reloc: %u\n",

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				mod->name, ELF32_R_TYPE(rela[i].r_info));

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			return -ENOEXEC;

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		}

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	}

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	return 0;

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}

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int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,

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			struct module *me)

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{

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	flush_cache_all();

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	return 0;

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}

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