/*
* arch/v850/kernel/module.c -- Architecture-specific module functions
*
* Copyright (C) 2002,03 NEC Electronics Corporation
* Copyright (C) 2002,03 Miles Bader <miles@gnu.org>
* Copyright (C) 2001,03 Rusty Russell
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of this
* archive for more details.
*
* Written by Miles Bader <miles@gnu.org>
*
* Derived in part from arch/ppc/kernel/module.c
*/
#include <linux/kernel.h>
#include <linux/vmalloc.h>
#include <linux/moduleloader.h>
#include <linux/elf.h>
#if 0
#define DEBUGP printk
#else
#define DEBUGP(fmt , ...)
#endif
void *module_alloc (unsigned long size)
{
return size == 0 ? 0 : vmalloc (size);
}
void module_free (struct module *mod, void *module_region)
{
vfree (module_region);
/* FIXME: If module_region == mod->init_region, trim exception
table entries. */
}
int module_finalize (const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
struct module *mod)
{
return 0;
}
/* Count how many different relocations (different symbol, different
addend) */
static unsigned int count_relocs(const Elf32_Rela *rela, unsigned int num)
{
unsigned int i, j, ret = 0;
/* Sure, this is order(n^2), but it's usually short, and not
time critical */
for (i = 0; i < num; i++) {
for (j = 0; j < i; j++) {
/* If this addend appeared before, it's
already been counted */
if (ELF32_R_SYM(rela[i].r_info)
== ELF32_R_SYM(rela[j].r_info)
&& rela[i].r_addend == rela[j].r_addend)
break;
}
if (j == i) ret++;
}
return ret;
}
/* Get the potential trampolines size required of the init and
non-init sections */
static unsigned long get_plt_size(const Elf32_Ehdr *hdr,
const Elf32_Shdr *sechdrs,
const char *secstrings,
int is_init)
{
unsigned long ret = 0;
unsigned i;
/* Everything marked ALLOC (this includes the exported
symbols) */
for (i = 1; i < hdr->e_shnum; i++) {
/* If it's called *.init*, and we're not init, we're
not interested */
if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0)
!= is_init)
continue;
if (sechdrs[i].sh_type == SHT_RELA) {
DEBUGP("Found relocations in section %u\n", i);
DEBUGP("Ptr: %p. Number: %u\n",
(void *)hdr + sechdrs[i].sh_offset,
sechdrs[i].sh_size / sizeof(Elf32_Rela));
ret += count_relocs((void *)hdr
+ sechdrs[i].sh_offset,
sechdrs[i].sh_size
/ sizeof(Elf32_Rela))
* sizeof(struct v850_plt_entry);
}
}
return ret;
}
int module_frob_arch_sections(Elf32_Ehdr *hdr,
Elf32_Shdr *sechdrs,
char *secstrings,
struct module *me)
{
unsigned int i;
/* Find .plt and .pltinit sections */
for (i = 0; i < hdr->e_shnum; i++) {
if (strcmp(secstrings + sechdrs[i].sh_name, ".init.plt") == 0)
me->arch.init_plt_section = i;
else if (strcmp(secstrings + sechdrs[i].sh_name, ".plt") == 0)
me->arch.core_plt_section = i;
}
if (!me->arch.core_plt_section || !me->arch.init_plt_section) {
printk("Module doesn't contain .plt or .plt.init sections.\n");
return -ENOEXEC;
}
/* Override their sizes */
sechdrs[me->arch.core_plt_section].sh_size
= get_plt_size(hdr, sechdrs, secstrings, 0);
sechdrs[me->arch.init_plt_section].sh_size
= get_plt_size(hdr, sechdrs, secstrings, 1);
return 0;
}
int apply_relocate (Elf32_Shdr *sechdrs, const char *strtab,
unsigned int symindex, unsigned int relsec,
struct module *mod)
{
printk ("Barf\n");
return -ENOEXEC;
}
/* Set up a trampoline in the PLT to bounce us to the distant function */
static uint32_t do_plt_call (void *location, Elf32_Addr val,
Elf32_Shdr *sechdrs, struct module *mod)
{
struct v850_plt_entry *entry;
/* Instructions used to do the indirect jump. */
uint32_t tramp[2];
/* We have to trash a register, so we assume that any control
transfer more than 21-bits away must be a function call
(so we can use a call-clobbered register). */
tramp[0] = 0x0621 + ((val & 0xffff) << 16); /* mov sym, r1 ... */
tramp[1] = ((val >> 16) & 0xffff) + 0x610000; /* ...; jmp r1 */
/* Init, or core PLT? */
if (location >= mod->module_core
&& location < mod->module_core + mod->core_size)
entry = (void *)sechdrs[mod->arch.core_plt_section].sh_addr;
else
entry = (void *)sechdrs[mod->arch.init_plt_section].sh_addr;
/* Find this entry, or if that fails, the next avail. entry */
while (entry->tramp[0])
if (entry->tramp[0] == tramp[0] && entry->tramp[1] == tramp[1])
return (uint32_t)entry;
else
entry++;
entry->tramp[0] = tramp[0];
entry->tramp[1] = tramp[1];
return (uint32_t)entry;
}
int apply_relocate_add (Elf32_Shdr *sechdrs, const char *strtab,
unsigned int symindex, unsigned int relsec,
struct module *mod)
{
unsigned int i;
Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
DEBUGP ("Applying relocate section %u to %u\n", relsec,
sechdrs[relsec].sh_info);
for (i = 0; i < sechdrs[relsec].sh_size / sizeof (*rela); i++) {
/* This is where to make the change */
uint32_t *loc
= ((void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ rela[i].r_offset);
/* This is the symbol it is referring to. Note that all
undefined symbols have been resolved. */
Elf32_Sym *sym
= ((Elf32_Sym *)sechdrs[symindex].sh_addr
+ ELF32_R_SYM (rela[i].r_info));
uint32_t val = sym->st_value + rela[i].r_addend;
switch (ELF32_R_TYPE (rela[i].r_info)) {
case R_V850_32:
/* We write two shorts instead of a long because even
32-bit insns only need half-word alignment, but
32-bit data writes need to be long-word aligned. */
val += ((uint16_t *)loc)[0];
val += ((uint16_t *)loc)[1] << 16;
((uint16_t *)loc)[0] = val & 0xffff;
((uint16_t *)loc)[1] = (val >> 16) & 0xffff;
break;
case R_V850_22_PCREL:
/* Maybe jump indirectly via a PLT table entry. */
if ((int32_t)(val - (uint32_t)loc) > 0x1fffff
|| (int32_t)(val - (uint32_t)loc) < -0x200000)
val = do_plt_call (loc, val, sechdrs, mod);
val -= (uint32_t)loc;
/* We write two shorts instead of a long because
even 32-bit insns only need half-word alignment,
but 32-bit data writes need to be long-word
aligned. */
((uint16_t *)loc)[0] =
(*(uint16_t *)loc & 0xffc0) /* opcode + reg */
| ((val >> 16) & 0xffc03f); /* offs high */
((uint16_t *)loc)[1] =
(val & 0xffff); /* offs low */
break;
default:
printk (KERN_ERR "module %s: Unknown reloc: %u\n",
mod->name, ELF32_R_TYPE (rela[i].r_info));
return -ENOEXEC;
}
}
return 0;
}
void
module_arch_cleanup(struct module *mod)
{
}
