RTOS/rtems
1
0
Fork 0
forked from Imagelibrary/rtems
Code Pull Requests Activity
Files
b51a1d07d007c665eda450ee48fc9b9d80e41251
rtems/cpukit/libdl/rtl-mdreloc-powerpc.c
Chris Johns b36c52097f libdl: Do not access the ELF file while the allocator is locked. 
- Load symbols before allocation.
- Parse reloc records and place any reloc recs in a cache to use
  while the allocator is locked.
- Relocate symbols after section allocation.
- Split section loading into allocation/locating and loading.
- Update all arch back-ends with a new reloc interface to control
  tramp handling.
- Add `-a` and `-t` to the object list shell command.

Closes #3741
2019-05-03 10:15:20 +10:00

548 lines
16 KiB
C
Raw Blame History

/*
* Taken from NetBSD and stripped of the relocations not needed on RTEMS.
*/
/* $NetBSD: ppc_reloc.c,v 1.44 2010/01/13 20:17:22 christos Exp $ */
#include <sys/cdefs.h>
#include <errno.h>
#include <inttypes.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <rtems/rtl/rtl.h>
#include "rtl-bit-alloc.h"
#include "rtl-elf.h"
#include "rtl-error.h"
#include <rtems/rtl/rtl-trace.h>
#include "rtl-unwind.h"
#include "rtl-unwind-dw2.h"
#define ha(x) ((((u_int32_t)(x) & 0x8000) ? \
((u_int32_t)(x) + 0x10000) : (u_int32_t)(x)) >> 16)
#define l(x) ((u_int32_t)(x) & 0xffff)
/*
* SDATA allocator.
*/
static rtems_rtl_bit_alloc* sdata;
static Elf_Addr
get_sda_base (void)
{
uint32_t sda_base;
__asm__ volatile (" mr %0, 13\n" : "=r" (sda_base));
return sda_base;
}
/*
* Access the variables via asm statements to avoid any fix up issues
* generated by the C compiler which thinks they belong in the .sdata
* section.
*/
#define GET_ADDR(_l, _v) \
__asm__ volatile (" lis %0, " #_l "@h\n" \
" ori %0, %0, " #_l "@l\n" : "=r" (_v))
static void*
get_sdata_start (void)
{
#if _ARCH_PPC64
return NULL;
#else
Elf_Addr addr;
GET_ADDR(__SDATA_START__, addr);
return (void*) addr;
#endif
}
#if !_ARCH_PPC64
static size_t
get_sdata_sbss_size (void)
{
Elf_Addr sdata_begin;
Elf_Addr sbss_end;
GET_ADDR(bsp_section_sdata_begin, sdata_begin);
GET_ADDR(bsp_section_sbss_end, sbss_end);
return sbss_end - sdata_begin;
}
static size_t
get_sdata_libdl_size (void)
{
Elf_Addr begin;
Elf_Addr end;
GET_ADDR(bsp_section_sdata_libdl_begin, begin);
GET_ADDR(bsp_section_sdata_libdl_end, end);
return end - begin;
}
#endif
uint32_t
rtems_rtl_elf_section_flags (const rtems_rtl_obj* obj,
const Elf_Shdr* shdr)
{
return 0;
}
uint32_t
rtems_rtl_elf_arch_parse_section (const rtems_rtl_obj* obj,
int section,
const char* name,
const Elf_Shdr* shdr,
const uint32_t flags)
{
#if !_ARCH_PPC64
struct {
const char* label;
size_t len;
} prefix[] = {
#define SEPARATED_PREFIX(_p) { _p, sizeof (_p) - 1 }
SEPARATED_PREFIX (".sdata"),
SEPARATED_PREFIX (".sbss"),
};
const size_t prefixes = sizeof (prefix) / sizeof (prefix[0]);
size_t p;
for (p = 0; p < prefixes; ++p)
{
if (strncmp (name, prefix[p].label, prefix[p].len) == 0)
return flags | RTEMS_RTL_OBJ_SECT_ARCH_ALLOC;
}
#endif
return flags;
}
bool
rtems_rtl_elf_arch_section_alloc (const rtems_rtl_obj* obj,
rtems_rtl_obj_sect* sect)
{
#if _ARCH_PPC64
rtems_rtl_set_error (ENOMEM, ".sdata no supported by ABI");
return false;
#else
if (rtems_rtl_trace (RTEMS_RTL_TRACE_DETAIL))
printf ("rtl: section: arch: alloc: name=%s size=%zu flags=%08" PRIx32 \
" order=%i link=%d info=%d\n",
sect->name, sect->size, sect->flags, sect->load_order,
sect->link, sect->info);
if (sdata == NULL)
{
sdata = rtems_rtl_bit_alloc_open (get_sdata_start (),
get_sdata_libdl_size (),
sizeof (uint32_t),
get_sdata_sbss_size ());
if (sdata == NULL)
{
rtems_rtl_set_error (ENOMEM, "no memory for sdata allocator");
return false;
}
}
sect->base = rtems_rtl_bit_alloc_balloc (sdata, sect->size);
if (sect->base == NULL)
{
rtems_rtl_set_error (ENOMEM, "no .sdata memory: %s", sect->name);
return false;
}
return true;
#endif
}
bool
rtems_rtl_elf_arch_section_free (const rtems_rtl_obj* obj,
rtems_rtl_obj_sect* sect)
{
#if !_ARCH_PPC64
if (rtems_rtl_trace (RTEMS_RTL_TRACE_DETAIL))
printf ("rtl: section: arch: free: name=%s size=%zu\n", sect->name, sect->size);
if (sdata != NULL)
rtems_rtl_bit_alloc_bfree (sdata, sect->base, sect->size);
#endif
return true;
}
bool
rtems_rtl_elf_rel_resolve_sym (Elf_Word type)
{
return true;
}
size_t
rtems_rtl_elf_relocate_tramp_max_size (void)
{
/*
* We have 4 instructions and each instruction is 32bits.
*/
return 4 * 4;
}
static void*
set_veneer (void* tramopline, Elf_Addr target)
{
/*
* http://shell-storm.org/online/Online-Assembler-and-Disassembler/
*
* lis 12,0x1234
* ori 12,12,0x5678
* mtctr 12
* bctr
*/
#if COMPILE_ASM
asm volatile (" lis 12,0x1234\n" \
" ori 12,12,0x5678\n" \
" mtctr 12\n" \
" bctr\n");
#endif
uint32_t* tramp = (uint32_t*) tramopline;
*tramp++ = 0x3d800000 | (target >> 16);
*tramp++ = 0x618c0000 | (target & 0xffff);
*tramp++ = 0x7d8903a6;
*tramp++ = 0x4e800420;
return tramp;
}
static size_t
get_veneer_size (int type)
{
(void) type;
return rtems_rtl_elf_relocate_tramp_max_size ();
}
/**
* The offsets in the reloc words.
*/
#define REL_R_OFFSET (0)
#define REL_R_INFO (1)
#define REL_R_ADDEND (2)
static rtems_rtl_elf_rel_status
rtems_rtl_elf_reloc_rela (rtems_rtl_obj* obj,
const Elf_Rela* rela,
const rtems_rtl_obj_sect* sect,
const char* symname,
const Elf_Byte syminfo,
const Elf_Word symvalue,
const bool parsing)
{
Elf_Addr* where;
Elf_Word tmp;
uint32_t mask = 0;
uint32_t bits = 0;
bool needs_tramp = false;
where = (Elf_Addr *)(sect->base + rela->r_offset);
switch (ELF_R_TYPE(rela->r_info)) {
case R_TYPE(NONE):
break;
case R_TYPE(32):
/*
* value:1; Field: word32; Expression: S + A
*/
if (!parsing) {
*where = symvalue + rela->r_addend;
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: ADDR32 %p @ %p in %s\n",
(void *)*(where), where, rtems_rtl_obj_oname (obj));
}
break;
case R_TYPE(14):
/*
* value:7; Field: low14*; Expression: (S + A) >> 2
*/
case R_TYPE(24):
/*
* value:2; Field: low24*; Expression: (S + A) >> 2
*/
if (ELF_R_TYPE(rela->r_info) == R_TYPE(14)) {
bits = 14;
mask = 0xfffc;
} else {
bits = 24;
mask = 0x3fffffc;
}
if (parsing && sect->base == 0) {
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: ADDR14/ADDR24 tramp cache\n");
return rtems_rtl_elf_rel_tramp_cache;
}
tmp = (symvalue + rela->r_addend) >> 2;
if (tmp > ((1<<bits) - 1 )) {
Elf_Word tramp_addr;
size_t tramp_size = get_veneer_size(ELF_R_TYPE(rela->r_info));
if (parsing) {
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: ADDR14/ADDR24 tramp add\n");
return rtems_rtl_elf_rel_tramp_add;
}
if (!rtems_rtl_obj_has_tramp_space (obj, tramp_size)) {
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: ADDR14/ADDR24 no tramp slot: %s\n", rtems_rtl_obj_oname (obj));
rtems_rtl_set_error (ENOMEM, "%s: tramp: no slot: ADDR14/ADDR24", sect->name);
return rtems_rtl_elf_rel_failure;
}
needs_tramp = true;
tramp_addr = (Elf_Addr) obj->tramp_brk;
obj->tramp_brk = set_veneer(obj->tramp_brk,
symvalue + rela->r_addend);
tmp = *where;
tmp &= ~mask;
tmp |= (tramp_addr + rela->r_addend) & mask;
}
else {
tmp = *where;
tmp &= ~mask;
tmp |= (symvalue + rela->r_addend) & mask;
}
if (!parsing) {
*where = tmp;
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: ADDR14/ADDR24%s %p @ %p in %s\n",
needs_tramp ? "(tramp)" : "",
(void *)*where, where, rtems_rtl_obj_oname (obj));
}
break;
case R_TYPE(16_HA):
/*
* value:6; Field:half16; Expression: #ha(S+A)
*/
if (!parsing) {
tmp = symvalue + rela->r_addend;
*(uint16_t *)where = (((tmp >> 16) + ((tmp & 0x8000) ? 1: 0)) & 0xffff);
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: 16_HA %p @ %p in %s\n",
(void *)*(where), where, rtems_rtl_obj_oname (obj));
}
break;
case R_TYPE(16_HI):
/*
* value:5; Field:half16; Expression: #hi(S+A)
*/
if (!parsing) {
*(uint16_t *)where = ((symvalue + rela->r_addend) >> 16) & 0xffff;
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: 16_HI %p @ %p in %s\n",
(void *)*where, where, rtems_rtl_obj_oname (obj));
}
break;
case R_TYPE(16_LO):
/*
* value:4; Field:half16; Expression: #lo(S+A)
*/
if (!parsing) {
*(uint16_t *)where = (symvalue + (rela->r_addend)) & 0xffff;
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: 16_LO %p @ %p in %s\n",
(void *)*where, where, rtems_rtl_obj_oname (obj));
}
break;
case R_TYPE(REL14):
/*
* value:11; Field:low14*; Expression:(S+A-P)>>2
*/
case R_TYPE(REL24):
/*
* value:10; Field:low24*; Expression:(S+A-P)>>2
*/
if (ELF_R_TYPE(rela->r_info) == R_TYPE(REL24)) {
mask = 0x3fffffc;
bits = 24;
}
else if (ELF_R_TYPE(rela->r_info) == R_TYPE(REL14)) {
mask = 0xfffc;
bits = 14;
}
if (parsing && sect->base == 0) {
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: REL24/REL14 tramp cache\n");
return rtems_rtl_elf_rel_tramp_cache;
}
tmp =((int) (symvalue + rela->r_addend - (Elf_Addr)where)) >> 2;
if (((Elf_Sword)tmp > ((1<<(bits-1)) - 1)) ||
((Elf_Sword)tmp < -(1<<(bits-1)))) {
Elf_Word tramp_addr;
size_t tramp_size = get_veneer_size(ELF_R_TYPE(rela->r_info));
if (parsing) {
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: REL24/REL14 tramp add\n");
return rtems_rtl_elf_rel_tramp_add;
}
if (!rtems_rtl_obj_has_tramp_space (obj, tramp_size)) {
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: REL24/REL14 no tramp slot: %s\n", rtems_rtl_obj_oname (obj));
rtems_rtl_set_error (ENOMEM, "%s: tramp: no slot: REL24/REL14", sect->name);
return rtems_rtl_elf_rel_failure;
}
needs_tramp = true;
tramp_addr = (Elf_Addr) obj->tramp_brk;
obj->tramp_brk = set_veneer(obj->tramp_brk,
symvalue + rela->r_addend);
tmp = *where;
tmp &= ~mask;
tmp |= (tramp_addr + rela->r_addend - (Elf_Addr)where) & mask;
}
else
{
tmp = *where;
tmp &= ~mask;
tmp |= (symvalue + rela->r_addend - (Elf_Addr)where) & mask;
}
if (!parsing) {
*where = tmp;
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: REL24/REL14%s %p @ %p in %s\n",
needs_tramp ? "(tramp)" : "",
(void *)*where, where, rtems_rtl_obj_oname (obj));
}
break;
case R_TYPE(REL32):
/*
* value:26; Field:word32*; Expression:S+A-P
*/
if (!parsing) {
*where = symvalue + rela->r_addend - (Elf_Addr)where;
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: REL32 %p @ %p in %s\n",
(void *)*where, where, rtems_rtl_obj_oname (obj));
}
break;
case R_TYPE(SDAREL16):
/*
* A sign-extended 16 bit value relative to _SDA_BASE_, for use with
* small data items.
*/
if (!parsing) {
Elf_Addr sda_base = get_sda_base ();
mask = 0xffff;
tmp = *((Elf32_Half*) where);
tmp &= ~mask;
tmp |= (symvalue + rela->r_addend - sda_base) & mask;
*((Elf32_Half*) where) = tmp;
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: SDAREL16 %p @ %p in %s\n",
(void *) (uintptr_t) *((Elf32_Half*) where),
where, rtems_rtl_obj_oname (obj));
}
break;
default:
printf ("rtl: reloc unknown: sym = %" PRIu32 ", type = %" PRIu32 ", offset = %p, "
"contents = %p\n",
ELF_R_SYM(rela->r_info), (uint32_t) ELF_R_TYPE(rela->r_info),
(void *)rela->r_offset, (void *)*where);
rtems_rtl_set_error (EINVAL,
"%s: Unsupported relocation type %" PRId32
"in non-PLT relocations",
sect->name, (uint32_t) ELF_R_TYPE(rela->r_info));
return rtems_rtl_elf_rel_failure;
}
return rtems_rtl_elf_rel_no_error;
}
rtems_rtl_elf_rel_status
rtems_rtl_elf_relocate_rela_tramp (rtems_rtl_obj* obj,
const Elf_Rela* rela,
const rtems_rtl_obj_sect* sect,
const char* symname,
const Elf_Byte syminfo,
const Elf_Word symvalue)
{
return rtems_rtl_elf_reloc_rela (obj,
rela,
sect,
symname,
syminfo,
symvalue,
true);
}
rtems_rtl_elf_rel_status
rtems_rtl_elf_relocate_rela (rtems_rtl_obj* obj,
const Elf_Rela* rela,
const rtems_rtl_obj_sect* sect,
const char* symname,
const Elf_Byte syminfo,
const Elf_Word symvalue)
{
return rtems_rtl_elf_reloc_rela (obj,
rela,
sect,
symname,
syminfo,
symvalue,
false);
}
rtems_rtl_elf_rel_status
rtems_rtl_elf_relocate_rel_tramp (rtems_rtl_obj* obj,
const Elf_Rel* rel,
const rtems_rtl_obj_sect* sect,
const char* symname,
const Elf_Byte syminfo,
const Elf_Word symvalue)
{
(void) obj;
(void) rel;
(void) sect;
(void) symname;
(void) syminfo;
(void) symvalue;
rtems_rtl_set_error (EINVAL, "rel type record not supported");
return rtems_rtl_elf_rel_failure;
}
rtems_rtl_elf_rel_status
rtems_rtl_elf_relocate_rel (rtems_rtl_obj* obj,
const Elf_Rel* rel,
const rtems_rtl_obj_sect* sect,
const char* symname,
const Elf_Byte syminfo,
const Elf_Word symvalue)
{
(void) obj;
(void) rel;
(void) sect;
(void) symname;
(void) syminfo;
(void) symvalue;
rtems_rtl_set_error (EINVAL, "rel type record not supported");
return rtems_rtl_elf_rel_failure;
}
bool
rtems_rtl_elf_unwind_parse (const rtems_rtl_obj* obj,
const char* name,
uint32_t flags)
{
return rtems_rtl_elf_unwind_dw2_parse (obj, name, flags);
}
bool
rtems_rtl_elf_unwind_register (rtems_rtl_obj* obj)
{
return rtems_rtl_elf_unwind_dw2_register (obj);
}
bool
rtems_rtl_elf_unwind_deregister (rtems_rtl_obj* obj)
{
return rtems_rtl_elf_unwind_dw2_deregister (obj);
}
View Git Blame Copy Permalink