446 строки
13 KiB
C
446 строки
13 KiB
C
/* Kernel module help for PPC64.
|
|
Copyright (C) 2001, 2003 Rusty Russell IBM Corporation.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/elf.h>
|
|
#include <linux/moduleloader.h>
|
|
#include <linux/err.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/bug.h>
|
|
#include <asm/module.h>
|
|
#include <asm/firmware.h>
|
|
#include <asm/code-patching.h>
|
|
#include <linux/sort.h>
|
|
|
|
#include "setup.h"
|
|
|
|
/* FIXME: We don't do .init separately. To do this, we'd need to have
|
|
a separate r2 value in the init and core section, and stub between
|
|
them, too.
|
|
|
|
Using a magic allocator which places modules within 32MB solves
|
|
this, and makes other things simpler. Anton?
|
|
--RR. */
|
|
#if 0
|
|
#define DEBUGP printk
|
|
#else
|
|
#define DEBUGP(fmt , ...)
|
|
#endif
|
|
|
|
/* Like PPC32, we need little trampolines to do > 24-bit jumps (into
|
|
the kernel itself). But on PPC64, these need to be used for every
|
|
jump, actually, to reset r2 (TOC+0x8000). */
|
|
struct ppc64_stub_entry
|
|
{
|
|
/* 28 byte jump instruction sequence (7 instructions) */
|
|
unsigned char jump[28];
|
|
unsigned char unused[4];
|
|
/* Data for the above code */
|
|
struct ppc64_opd_entry opd;
|
|
};
|
|
|
|
/* We use a stub to fix up r2 (TOC ptr) and to jump to the (external)
|
|
function which may be more than 24-bits away. We could simply
|
|
patch the new r2 value and function pointer into the stub, but it's
|
|
significantly shorter to put these values at the end of the stub
|
|
code, and patch the stub address (32-bits relative to the TOC ptr,
|
|
r2) into the stub. */
|
|
static struct ppc64_stub_entry ppc64_stub =
|
|
{ .jump = {
|
|
0x3d, 0x82, 0x00, 0x00, /* addis r12,r2, <high> */
|
|
0x39, 0x8c, 0x00, 0x00, /* addi r12,r12, <low> */
|
|
/* Save current r2 value in magic place on the stack. */
|
|
0xf8, 0x41, 0x00, 0x28, /* std r2,40(r1) */
|
|
0xe9, 0x6c, 0x00, 0x20, /* ld r11,32(r12) */
|
|
0xe8, 0x4c, 0x00, 0x28, /* ld r2,40(r12) */
|
|
0x7d, 0x69, 0x03, 0xa6, /* mtctr r11 */
|
|
0x4e, 0x80, 0x04, 0x20 /* bctr */
|
|
} };
|
|
|
|
/* Count how many different 24-bit relocations (different symbol,
|
|
different addend) */
|
|
static unsigned int count_relocs(const Elf64_Rela *rela, unsigned int num)
|
|
{
|
|
unsigned int i, r_info, r_addend, _count_relocs;
|
|
|
|
/* FIXME: Only count external ones --RR */
|
|
_count_relocs = 0;
|
|
r_info = 0;
|
|
r_addend = 0;
|
|
for (i = 0; i < num; i++)
|
|
/* Only count 24-bit relocs, others don't need stubs */
|
|
if (ELF64_R_TYPE(rela[i].r_info) == R_PPC_REL24 &&
|
|
(r_info != ELF64_R_SYM(rela[i].r_info) ||
|
|
r_addend != rela[i].r_addend)) {
|
|
_count_relocs++;
|
|
r_info = ELF64_R_SYM(rela[i].r_info);
|
|
r_addend = rela[i].r_addend;
|
|
}
|
|
|
|
return _count_relocs;
|
|
}
|
|
|
|
static int relacmp(const void *_x, const void *_y)
|
|
{
|
|
const Elf64_Rela *x, *y;
|
|
|
|
y = (Elf64_Rela *)_x;
|
|
x = (Elf64_Rela *)_y;
|
|
|
|
/* Compare the entire r_info (as opposed to ELF64_R_SYM(r_info) only) to
|
|
* make the comparison cheaper/faster. It won't affect the sorting or
|
|
* the counting algorithms' performance
|
|
*/
|
|
if (x->r_info < y->r_info)
|
|
return -1;
|
|
else if (x->r_info > y->r_info)
|
|
return 1;
|
|
else if (x->r_addend < y->r_addend)
|
|
return -1;
|
|
else if (x->r_addend > y->r_addend)
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
static void relaswap(void *_x, void *_y, int size)
|
|
{
|
|
uint64_t *x, *y, tmp;
|
|
int i;
|
|
|
|
y = (uint64_t *)_x;
|
|
x = (uint64_t *)_y;
|
|
|
|
for (i = 0; i < sizeof(Elf64_Rela) / sizeof(uint64_t); i++) {
|
|
tmp = x[i];
|
|
x[i] = y[i];
|
|
y[i] = tmp;
|
|
}
|
|
}
|
|
|
|
/* Get size of potential trampolines required. */
|
|
static unsigned long get_stubs_size(const Elf64_Ehdr *hdr,
|
|
const Elf64_Shdr *sechdrs)
|
|
{
|
|
/* One extra reloc so it's always 0-funcaddr terminated */
|
|
unsigned long relocs = 1;
|
|
unsigned i;
|
|
|
|
/* Every relocated section... */
|
|
for (i = 1; i < hdr->e_shnum; i++) {
|
|
if (sechdrs[i].sh_type == SHT_RELA) {
|
|
DEBUGP("Found relocations in section %u\n", i);
|
|
DEBUGP("Ptr: %p. Number: %lu\n",
|
|
(void *)sechdrs[i].sh_addr,
|
|
sechdrs[i].sh_size / sizeof(Elf64_Rela));
|
|
|
|
/* Sort the relocation information based on a symbol and
|
|
* addend key. This is a stable O(n*log n) complexity
|
|
* alogrithm but it will reduce the complexity of
|
|
* count_relocs() to linear complexity O(n)
|
|
*/
|
|
sort((void *)sechdrs[i].sh_addr,
|
|
sechdrs[i].sh_size / sizeof(Elf64_Rela),
|
|
sizeof(Elf64_Rela), relacmp, relaswap);
|
|
|
|
relocs += count_relocs((void *)sechdrs[i].sh_addr,
|
|
sechdrs[i].sh_size
|
|
/ sizeof(Elf64_Rela));
|
|
}
|
|
}
|
|
|
|
DEBUGP("Looks like a total of %lu stubs, max\n", relocs);
|
|
return relocs * sizeof(struct ppc64_stub_entry);
|
|
}
|
|
|
|
static void dedotify_versions(struct modversion_info *vers,
|
|
unsigned long size)
|
|
{
|
|
struct modversion_info *end;
|
|
|
|
for (end = (void *)vers + size; vers < end; vers++)
|
|
if (vers->name[0] == '.')
|
|
memmove(vers->name, vers->name+1, strlen(vers->name));
|
|
}
|
|
|
|
/* Undefined symbols which refer to .funcname, hack to funcname */
|
|
static void dedotify(Elf64_Sym *syms, unsigned int numsyms, char *strtab)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 1; i < numsyms; i++) {
|
|
if (syms[i].st_shndx == SHN_UNDEF) {
|
|
char *name = strtab + syms[i].st_name;
|
|
if (name[0] == '.')
|
|
memmove(name, name+1, strlen(name));
|
|
}
|
|
}
|
|
}
|
|
|
|
int module_frob_arch_sections(Elf64_Ehdr *hdr,
|
|
Elf64_Shdr *sechdrs,
|
|
char *secstrings,
|
|
struct module *me)
|
|
{
|
|
unsigned int i;
|
|
|
|
/* Find .toc and .stubs sections, symtab and strtab */
|
|
for (i = 1; i < hdr->e_shnum; i++) {
|
|
char *p;
|
|
if (strcmp(secstrings + sechdrs[i].sh_name, ".stubs") == 0)
|
|
me->arch.stubs_section = i;
|
|
else if (strcmp(secstrings + sechdrs[i].sh_name, ".toc") == 0)
|
|
me->arch.toc_section = i;
|
|
else if (strcmp(secstrings+sechdrs[i].sh_name,"__versions")==0)
|
|
dedotify_versions((void *)hdr + sechdrs[i].sh_offset,
|
|
sechdrs[i].sh_size);
|
|
|
|
/* We don't handle .init for the moment: rename to _init */
|
|
while ((p = strstr(secstrings + sechdrs[i].sh_name, ".init")))
|
|
p[0] = '_';
|
|
|
|
if (sechdrs[i].sh_type == SHT_SYMTAB)
|
|
dedotify((void *)hdr + sechdrs[i].sh_offset,
|
|
sechdrs[i].sh_size / sizeof(Elf64_Sym),
|
|
(void *)hdr
|
|
+ sechdrs[sechdrs[i].sh_link].sh_offset);
|
|
}
|
|
|
|
if (!me->arch.stubs_section) {
|
|
printk("%s: doesn't contain .stubs.\n", me->name);
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
/* If we don't have a .toc, just use .stubs. We need to set r2
|
|
to some reasonable value in case the module calls out to
|
|
other functions via a stub, or if a function pointer escapes
|
|
the module by some means. */
|
|
if (!me->arch.toc_section)
|
|
me->arch.toc_section = me->arch.stubs_section;
|
|
|
|
/* Override the stubs size */
|
|
sechdrs[me->arch.stubs_section].sh_size = get_stubs_size(hdr, sechdrs);
|
|
return 0;
|
|
}
|
|
|
|
int apply_relocate(Elf64_Shdr *sechdrs,
|
|
const char *strtab,
|
|
unsigned int symindex,
|
|
unsigned int relsec,
|
|
struct module *me)
|
|
{
|
|
printk(KERN_ERR "%s: Non-ADD RELOCATION unsupported\n", me->name);
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
/* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this
|
|
gives the value maximum span in an instruction which uses a signed
|
|
offset) */
|
|
static inline unsigned long my_r2(Elf64_Shdr *sechdrs, struct module *me)
|
|
{
|
|
return sechdrs[me->arch.toc_section].sh_addr + 0x8000;
|
|
}
|
|
|
|
/* Both low and high 16 bits are added as SIGNED additions, so if low
|
|
16 bits has high bit set, high 16 bits must be adjusted. These
|
|
macros do that (stolen from binutils). */
|
|
#define PPC_LO(v) ((v) & 0xffff)
|
|
#define PPC_HI(v) (((v) >> 16) & 0xffff)
|
|
#define PPC_HA(v) PPC_HI ((v) + 0x8000)
|
|
|
|
/* Patch stub to reference function and correct r2 value. */
|
|
static inline int create_stub(Elf64_Shdr *sechdrs,
|
|
struct ppc64_stub_entry *entry,
|
|
struct ppc64_opd_entry *opd,
|
|
struct module *me)
|
|
{
|
|
Elf64_Half *loc1, *loc2;
|
|
long reladdr;
|
|
|
|
*entry = ppc64_stub;
|
|
|
|
loc1 = (Elf64_Half *)&entry->jump[2];
|
|
loc2 = (Elf64_Half *)&entry->jump[6];
|
|
|
|
/* Stub uses address relative to r2. */
|
|
reladdr = (unsigned long)entry - my_r2(sechdrs, me);
|
|
if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
|
|
printk("%s: Address %p of stub out of range of %p.\n",
|
|
me->name, (void *)reladdr, (void *)my_r2);
|
|
return 0;
|
|
}
|
|
DEBUGP("Stub %p get data from reladdr %li\n", entry, reladdr);
|
|
|
|
*loc1 = PPC_HA(reladdr);
|
|
*loc2 = PPC_LO(reladdr);
|
|
entry->opd.funcaddr = opd->funcaddr;
|
|
entry->opd.r2 = opd->r2;
|
|
return 1;
|
|
}
|
|
|
|
/* Create stub to jump to function described in this OPD: we need the
|
|
stub to set up the TOC ptr (r2) for the function. */
|
|
static unsigned long stub_for_addr(Elf64_Shdr *sechdrs,
|
|
unsigned long opdaddr,
|
|
struct module *me)
|
|
{
|
|
struct ppc64_stub_entry *stubs;
|
|
struct ppc64_opd_entry *opd = (void *)opdaddr;
|
|
unsigned int i, num_stubs;
|
|
|
|
num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*stubs);
|
|
|
|
/* Find this stub, or if that fails, the next avail. entry */
|
|
stubs = (void *)sechdrs[me->arch.stubs_section].sh_addr;
|
|
for (i = 0; stubs[i].opd.funcaddr; i++) {
|
|
BUG_ON(i >= num_stubs);
|
|
|
|
if (stubs[i].opd.funcaddr == opd->funcaddr)
|
|
return (unsigned long)&stubs[i];
|
|
}
|
|
|
|
if (!create_stub(sechdrs, &stubs[i], opd, me))
|
|
return 0;
|
|
|
|
return (unsigned long)&stubs[i];
|
|
}
|
|
|
|
/* We expect a noop next: if it is, replace it with instruction to
|
|
restore r2. */
|
|
static int restore_r2(u32 *instruction, struct module *me)
|
|
{
|
|
if (*instruction != PPC_NOP_INSTR) {
|
|
printk("%s: Expect noop after relocate, got %08x\n",
|
|
me->name, *instruction);
|
|
return 0;
|
|
}
|
|
*instruction = 0xe8410028; /* ld r2,40(r1) */
|
|
return 1;
|
|
}
|
|
|
|
int apply_relocate_add(Elf64_Shdr *sechdrs,
|
|
const char *strtab,
|
|
unsigned int symindex,
|
|
unsigned int relsec,
|
|
struct module *me)
|
|
{
|
|
unsigned int i;
|
|
Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
|
|
Elf64_Sym *sym;
|
|
unsigned long *location;
|
|
unsigned long value;
|
|
|
|
DEBUGP("Applying ADD 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 */
|
|
location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
|
|
+ rela[i].r_offset;
|
|
/* This is the symbol it is referring to */
|
|
sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
|
|
+ ELF64_R_SYM(rela[i].r_info);
|
|
|
|
DEBUGP("RELOC at %p: %li-type as %s (%lu) + %li\n",
|
|
location, (long)ELF64_R_TYPE(rela[i].r_info),
|
|
strtab + sym->st_name, (unsigned long)sym->st_value,
|
|
(long)rela[i].r_addend);
|
|
|
|
/* `Everything is relative'. */
|
|
value = sym->st_value + rela[i].r_addend;
|
|
|
|
switch (ELF64_R_TYPE(rela[i].r_info)) {
|
|
case R_PPC64_ADDR32:
|
|
/* Simply set it */
|
|
*(u32 *)location = value;
|
|
break;
|
|
|
|
case R_PPC64_ADDR64:
|
|
/* Simply set it */
|
|
*(unsigned long *)location = value;
|
|
break;
|
|
|
|
case R_PPC64_TOC:
|
|
*(unsigned long *)location = my_r2(sechdrs, me);
|
|
break;
|
|
|
|
case R_PPC64_TOC16:
|
|
/* Subtract TOC pointer */
|
|
value -= my_r2(sechdrs, me);
|
|
if (value + 0x8000 > 0xffff) {
|
|
printk("%s: bad TOC16 relocation (%lu)\n",
|
|
me->name, value);
|
|
return -ENOEXEC;
|
|
}
|
|
*((uint16_t *) location)
|
|
= (*((uint16_t *) location) & ~0xffff)
|
|
| (value & 0xffff);
|
|
break;
|
|
|
|
case R_PPC64_TOC16_DS:
|
|
/* Subtract TOC pointer */
|
|
value -= my_r2(sechdrs, me);
|
|
if ((value & 3) != 0 || value + 0x8000 > 0xffff) {
|
|
printk("%s: bad TOC16_DS relocation (%lu)\n",
|
|
me->name, value);
|
|
return -ENOEXEC;
|
|
}
|
|
*((uint16_t *) location)
|
|
= (*((uint16_t *) location) & ~0xfffc)
|
|
| (value & 0xfffc);
|
|
break;
|
|
|
|
case R_PPC_REL24:
|
|
/* FIXME: Handle weak symbols here --RR */
|
|
if (sym->st_shndx == SHN_UNDEF) {
|
|
/* External: go via stub */
|
|
value = stub_for_addr(sechdrs, value, me);
|
|
if (!value)
|
|
return -ENOENT;
|
|
if (!restore_r2((u32 *)location + 1, me))
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
/* Convert value to relative */
|
|
value -= (unsigned long)location;
|
|
if (value + 0x2000000 > 0x3ffffff || (value & 3) != 0){
|
|
printk("%s: REL24 %li out of range!\n",
|
|
me->name, (long int)value);
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
/* Only replace bits 2 through 26 */
|
|
*(uint32_t *)location
|
|
= (*(uint32_t *)location & ~0x03fffffc)
|
|
| (value & 0x03fffffc);
|
|
break;
|
|
|
|
case R_PPC64_REL64:
|
|
/* 64 bits relative (used by features fixups) */
|
|
*location = value - (unsigned long)location;
|
|
break;
|
|
|
|
default:
|
|
printk("%s: Unknown ADD relocation: %lu\n",
|
|
me->name,
|
|
(unsigned long)ELF64_R_TYPE(rela[i].r_info));
|
|
return -ENOEXEC;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|