cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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module.c (2336B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
      4 * Copyright (C) 2007-2009 PetaLogix
      5 */
      6
      7#include <linux/export.h>
      8#include <linux/moduleloader.h>
      9#include <linux/kernel.h>
     10#include <linux/elf.h>
     11#include <linux/vmalloc.h>
     12#include <linux/fs.h>
     13#include <linux/string.h>
     14#include <linux/pgtable.h>
     15
     16#include <asm/cacheflush.h>
     17
     18int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
     19	unsigned int symindex, unsigned int relsec, struct module *module)
     20{
     21
     22	unsigned int i;
     23	Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
     24	Elf32_Sym *sym;
     25	unsigned long int *location;
     26	unsigned long int value;
     27
     28	pr_debug("Applying add relocation section %u to %u\n",
     29		relsec, sechdrs[relsec].sh_info);
     30
     31	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
     32
     33		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr +
     34				rela[i].r_offset;
     35		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr +
     36			ELF32_R_SYM(rela[i].r_info);
     37		value = sym->st_value + rela[i].r_addend;
     38
     39		switch (ELF32_R_TYPE(rela[i].r_info)) {
     40
     41		/*
     42		 * Be careful! mb-gcc / mb-ld splits the relocs between the
     43		 * text and the reloc table. In general this means we must
     44		 * read the current contents of (*location), add any offset
     45		 * then store the result back in
     46		 */
     47
     48		case R_MICROBLAZE_32:
     49			*location = value;
     50			break;
     51
     52		case R_MICROBLAZE_64:
     53			location[0] = (location[0] & 0xFFFF0000) |
     54					(value >> 16);
     55			location[1] = (location[1] & 0xFFFF0000) |
     56					(value & 0xFFFF);
     57			break;
     58
     59		case R_MICROBLAZE_64_PCREL:
     60			value -= (unsigned long int)(location) + 4;
     61			location[0] = (location[0] & 0xFFFF0000) |
     62					(value >> 16);
     63			location[1] = (location[1] & 0xFFFF0000) |
     64					(value & 0xFFFF);
     65			pr_debug("R_MICROBLAZE_64_PCREL (%08lx)\n",
     66				value);
     67			break;
     68
     69		case R_MICROBLAZE_32_PCREL_LO:
     70			pr_debug("R_MICROBLAZE_32_PCREL_LO\n");
     71			break;
     72
     73		case R_MICROBLAZE_64_NONE:
     74			pr_debug("R_MICROBLAZE_64_NONE\n");
     75			break;
     76
     77		case R_MICROBLAZE_NONE:
     78			pr_debug("R_MICROBLAZE_NONE\n");
     79			break;
     80
     81		default:
     82			pr_err("module %s: Unknown relocation: %u\n",
     83				module->name,
     84				ELF32_R_TYPE(rela[i].r_info));
     85			return -ENOEXEC;
     86		}
     87	}
     88	return 0;
     89}
     90
     91int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
     92		struct module *module)
     93{
     94	flush_dcache();
     95	return 0;
     96}