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 (2595B)

      1// SPDX-License-Identifier: GPL-2.0
      2// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
      3
      4#include <linux/moduleloader.h>
      5#include <linux/elf.h>
      6#include <linux/mm.h>
      7#include <linux/vmalloc.h>
      8#include <linux/slab.h>
      9#include <linux/fs.h>
     10#include <linux/string.h>
     11#include <linux/kernel.h>
     12#include <linux/spinlock.h>
     13
     14#ifdef CONFIG_CPU_CK810
     15#define IS_BSR32(hi16, lo16)		(((hi16) & 0xFC00) == 0xE000)
     16#define IS_JSRI32(hi16, lo16)		((hi16) == 0xEAE0)
     17
     18#define CHANGE_JSRI_TO_LRW(addr) do {					\
     19	*(uint16_t *)(addr) = (*(uint16_t *)(addr) & 0xFF9F) | 0x001a;	\
     20	*((uint16_t *)(addr) + 1) = *((uint16_t *)(addr) + 1) & 0xFFFF;	\
     21} while (0)
     22
     23#define SET_JSR32_R26(addr) do {		\
     24	*(uint16_t *)(addr) = 0xE8Fa;		\
     25	*((uint16_t *)(addr) + 1) = 0x0000;	\
     26} while (0)
     27
     28static void jsri_2_lrw_jsr(uint32_t *location)
     29{
     30	uint16_t *location_tmp = (uint16_t *)location;
     31
     32	if (IS_BSR32(*location_tmp, *(location_tmp + 1)))
     33		return;
     34
     35	if (IS_JSRI32(*location_tmp, *(location_tmp + 1))) {
     36		/* jsri 0x...  --> lrw r26, 0x... */
     37		CHANGE_JSRI_TO_LRW(location);
     38		/* lsli r0, r0 --> jsr r26 */
     39		SET_JSR32_R26(location + 1);
     40	}
     41}
     42#else
     43static void inline jsri_2_lrw_jsr(uint32_t *location)
     44{
     45	return;
     46}
     47#endif
     48
     49int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
     50		unsigned int symindex, unsigned int relsec, struct module *me)
     51{
     52	unsigned int i;
     53	Elf32_Rela	*rel = (void *) sechdrs[relsec].sh_addr;
     54	Elf32_Sym	*sym;
     55	uint32_t	*location;
     56	short		*temp;
     57
     58	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
     59		/* This is where to make the change */
     60		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
     61							+ rel[i].r_offset;
     62		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
     63						+ ELF32_R_SYM(rel[i].r_info);
     64
     65		switch (ELF32_R_TYPE(rel[i].r_info)) {
     66		case R_CSKY_32:
     67			/* We add the value into the location given */
     68			*location = rel[i].r_addend + sym->st_value;
     69			break;
     70		case R_CSKY_PC32:
     71			/* Add the value, subtract its position */
     72			*location = rel[i].r_addend + sym->st_value
     73							- (uint32_t)location;
     74			break;
     75		case R_CSKY_PCRELJSR_IMM11BY2:
     76			break;
     77		case R_CSKY_PCRELJSR_IMM26BY2:
     78			jsri_2_lrw_jsr(location);
     79			break;
     80		case R_CSKY_ADDR_HI16:
     81			temp = ((short  *)location) + 1;
     82			*temp = (short)
     83				((rel[i].r_addend + sym->st_value) >> 16);
     84			break;
     85		case R_CSKY_ADDR_LO16:
     86			temp = ((short  *)location) + 1;
     87			*temp = (short)
     88				((rel[i].r_addend + sym->st_value) & 0xffff);
     89			break;
     90		default:
     91			pr_err("module %s: Unknown relocation: %u\n",
     92				me->name, ELF32_R_TYPE(rel[i].r_info));
     93			return -ENOEXEC;
     94		}
     95	}
     96	return 0;
     97}