linux/linux-5.4.31/arch/c6x/kernel/module.c

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2024-01-30 10:43:28 +00:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* Port on Texas Instruments TMS320C6x architecture
*
* Copyright (C) 2005, 2009, 2010, 2011 Texas Instruments Incorporated
* Author: Thomas Charleux (thomas.charleux@jaluna.com)
*/
#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/kernel.h>
static inline int fixup_pcr(u32 *ip, Elf32_Addr dest, u32 maskbits, int shift)
{
u32 opcode;
long ep = (long)ip & ~31;
long delta = ((long)dest - ep) >> 2;
long mask = (1 << maskbits) - 1;
if ((delta >> (maskbits - 1)) == 0 ||
(delta >> (maskbits - 1)) == -1) {
opcode = *ip;
opcode &= ~(mask << shift);
opcode |= ((delta & mask) << shift);
*ip = opcode;
pr_debug("REL PCR_S%d[%p] dest[%p] opcode[%08x]\n",
maskbits, ip, (void *)dest, opcode);
return 0;
}
pr_err("PCR_S%d reloc %p -> %p out of range!\n",
maskbits, ip, (void *)dest);
return -1;
}
/*
* apply a RELA relocation
*/
int apply_relocate_add(Elf32_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *me)
{
Elf32_Rela *rel = (void *) sechdrs[relsec].sh_addr;
Elf_Sym *sym;
u32 *location, opcode;
unsigned int i;
Elf32_Addr v;
Elf_Addr offset = 0;
pr_debug("Applying relocate section %u to %u with offset 0x%x\n",
relsec, sechdrs[relsec].sh_info, offset);
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
/* This is where to make the change */
location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ rel[i].r_offset - offset;
/* This is the symbol it is referring to. Note that all
undefined symbols have been resolved. */
sym = (Elf_Sym *)sechdrs[symindex].sh_addr
+ ELF32_R_SYM(rel[i].r_info);
/* this is the adjustment to be made */
v = sym->st_value + rel[i].r_addend;
switch (ELF32_R_TYPE(rel[i].r_info)) {
case R_C6000_ABS32:
pr_debug("RELA ABS32: [%p] = 0x%x\n", location, v);
*location = v;
break;
case R_C6000_ABS16:
pr_debug("RELA ABS16: [%p] = 0x%x\n", location, v);
*(u16 *)location = v;
break;
case R_C6000_ABS8:
pr_debug("RELA ABS8: [%p] = 0x%x\n", location, v);
*(u8 *)location = v;
break;
case R_C6000_ABS_L16:
opcode = *location;
opcode &= ~0x7fff80;
opcode |= ((v & 0xffff) << 7);
pr_debug("RELA ABS_L16[%p] v[0x%x] opcode[0x%x]\n",
location, v, opcode);
*location = opcode;
break;
case R_C6000_ABS_H16:
opcode = *location;
opcode &= ~0x7fff80;
opcode |= ((v >> 9) & 0x7fff80);
pr_debug("RELA ABS_H16[%p] v[0x%x] opcode[0x%x]\n",
location, v, opcode);
*location = opcode;
break;
case R_C6000_PCR_S21:
if (fixup_pcr(location, v, 21, 7))
return -ENOEXEC;
break;
case R_C6000_PCR_S12:
if (fixup_pcr(location, v, 12, 16))
return -ENOEXEC;
break;
case R_C6000_PCR_S10:
if (fixup_pcr(location, v, 10, 13))
return -ENOEXEC;
break;
default:
pr_err("module %s: Unknown RELA relocation: %u\n",
me->name, ELF32_R_TYPE(rel[i].r_info));
return -ENOEXEC;
}
}
return 0;
}