/*
* Taken from NetBSD and stripped of the relocations not needed on RTEMS.
*/
/* $NetBSD: mdreloc.c,v 1.33 2010/01/14 12:12:07 skrll Exp $ */
#include <sys/cdefs.h>
#include <errno.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unwind.h>
#include <unwind-arm-common.h>
#include <rtems/rtl/rtl.h>
#include "rtl-elf.h"
#include "rtl-error.h"
#include "rtl-trace.h"
#include "rtl-unwind.h"
/*
* It is possible for the compiler to emit relocations for unaligned data.
* We handle this situation with these inlines.
*/
#define RELOC_ALIGNED_P(x) \
(((uintptr_t)(x) & (sizeof(void *) - 1)) == 0)
#define SHT_ARM_EXIDX 0x70000001 /* Section holds ARM unwind info. */
static inline Elf_Addr
load_ptr(void *where)
{
Elf_Addr res;
memcpy(&res, where, sizeof(res));
return (res);
}
static inline void
store_ptr(void *where, Elf_Addr val)
{
memcpy(where, &val, sizeof(val));
}
/*
* The address of Thumb function symbols is it's real address plus one.
* This is done by compiler, thus do not consider symtype here.
*/
static inline int
isThumb(Elf_Word symvalue)
{
if ((symvalue & 0x1) == 0x1)
return true;
else return false;
}
static inline Elf_SOff
sign_extend31(Elf_Addr val)
{
if (0x40000000 & val)
val = ~((Elf_Addr)0x7fffffff) | (0x7fffffff & val);
return 0x7fffffff & val;
}
uint32_t
rtems_rtl_elf_section_flags (const rtems_rtl_obj_t* obj,
const Elf_Shdr* shdr)
{
uint32_t flags = 0;
if (shdr->sh_type == SHT_ARM_EXIDX)
flags = RTEMS_RTL_OBJ_SECT_EH | RTEMS_RTL_OBJ_SECT_LOAD;
return flags;
}
bool
rtems_rtl_elf_rel_resolve_sym (Elf_Word type)
{
return true;
}
bool
rtems_rtl_elf_relocate_rela (const rtems_rtl_obj_t* obj,
const Elf_Rela* rela,
const rtems_rtl_obj_sect_t* sect,
const char* symname,
const Elf_Byte syminfo,
const Elf_Word symvalue)
{
rtems_rtl_set_error (EINVAL, "rela type record not supported");
return false;
}
bool
rtems_rtl_elf_relocate_rel (const rtems_rtl_obj_t* obj,
const Elf_Rel* rel,
const rtems_rtl_obj_sect_t* sect,
const char* symname,
const Elf_Byte syminfo,
const Elf_Word symvalue)
{
Elf_Addr *where;
Elf_Addr tmp;
Elf_Word insn, addend;
Elf_Word sign, i1, i2;
uint16_t lower_insn, upper_insn;
where = (Elf_Addr *)(sect->base + rel->r_offset);
switch (ELF_R_TYPE(rel->r_info)) {
case R_TYPE(NONE):
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) {
printf ("rtl: NONE %p in %s\n", where, rtems_rtl_obj_oname (obj));
}
break;
case R_TYPE(CALL): /* BL/BLX */
case R_TYPE(JUMP24): /* B/BL<cond> */
insn = *where;
if (insn & 0x00800000)
addend = insn | 0xff000000;
else addend = insn & 0x00ffffff;
if (isThumb(symvalue)) {
if ((insn & 0xfe000000) == 0xfa000000); /* Already blx */
else {
if ((insn & 0xff000000) == 0xeb000000) { /* BL <label> */
*where = (insn & 0x00ffffff) | 0xfa000000; /* BL-->BLX */
} else {
printf("JUMP24 is not suppored from arm to thumb\n");
return false;
}
}
}
tmp = symvalue + (addend << 2) - (Elf_Addr)where;
tmp = (Elf_Sword)tmp >> 2;
if (((Elf_Sword)tmp > 0x7fffff) || ((Elf_Sword)tmp < -0x800000)) {
printf("CALL/JUMP24 Overflow\n");
return false;
}
*where = (*where & 0xff000000) | (tmp & 0xffffff);
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: JUMP24/PC24/CALL %p @ %p in %s\n",
(void *)*where, where, rtems_rtl_obj_oname (obj));
break;
case R_TYPE(V4BX):
/* Miscellaneous, ignore */
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) {
printf ("rtl: V4BX %p @ %p in %s\n",
(void *)*where, where, rtems_rtl_obj_oname (obj));
}
break;
case R_TYPE(MOVT_ABS):
case R_TYPE(MOVW_ABS_NC):
insn = *where;
addend = ((insn >> 4) & 0xf000) | (insn & 0x0fff);
if (addend & 0x8000)
addend |= 0xffff0000;
tmp = symvalue + addend;
if (ELF_R_TYPE(rel->r_info) == R_TYPE(MOVW_ABS_NC))
tmp &= 0xffff;
else {
tmp = (Elf_Sword)tmp >> 16;
if (((Elf_Sword)tmp > 0x7fff) || ((Elf_Sword)tmp < -0x8000)) {
printf("MOVT_ABS Overflow\n");
return false;
}
}
*where = (insn & 0xfff0f000) | ((tmp & 0xf000) << 4) | (tmp & 0xfff);
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: MOVT_ABS/MOVW_ABS_NC %p @ %p in %s\n",
(void *)*where, where, rtems_rtl_obj_oname (obj));
break;
case R_TYPE(REL32): /* word32 (S + A) | T - P */
case R_TYPE(ABS32): /* word32 (S + A) | T */
case R_TYPE(GLOB_DAT): /* word32 (S + A) | T */
case R_TYPE(PREL31): /* word32 (S + A) | T - P */
case R_TYPE(TARGET2): /* Equivalent to REL32 */
if (__predict_true(RELOC_ALIGNED_P(where))) {
tmp = *where + symvalue;
if (isThumb(symvalue))
tmp |= 1;
if (ELF_R_TYPE(rel->r_info) == R_TYPE(REL32) ||
ELF_R_TYPE(rel->r_info) == R_TYPE(TARGET2))
tmp -= (Elf_Addr)where;
else if (ELF_R_TYPE(rel->r_info) == R_TYPE(PREL31))
tmp = sign_extend31(tmp - (Elf_Addr)where);
*where = tmp;
} else {
tmp = load_ptr(where) + symvalue;
if (isThumb(symvalue))
tmp |= 1;
if (ELF_R_TYPE(rel->r_info) == R_TYPE(REL32) ||
ELF_R_TYPE(rel->r_info) == R_TYPE(TARGET2))
tmp -= (Elf_Addr)where;
else if (ELF_R_TYPE(rel->r_info) == R_TYPE(PREL31))
tmp = sign_extend31(tmp - (Elf_Addr)where);
store_ptr(where, tmp);
}
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: REL32/ABS32/GLOB_DAT/PREL31/TARGET2 %p @ %p in %s\n",
(void *)tmp, where, rtems_rtl_obj_oname (obj));
break;
case R_TYPE(THM_MOVT_ABS):
case R_TYPE(THM_MOVW_ABS_NC):
upper_insn = *(uint16_t *)where;
lower_insn = *((uint16_t *)where + 1);
addend = ((upper_insn & 0x000f) << 12) | ((upper_insn & 0x0400) << 1) |
((lower_insn & 0x7000) >> 4) | (lower_insn & 0x00ff);
addend = (addend ^ 0x8000) - 0x8000;
tmp = addend + symvalue;
if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS)
tmp >>= 16;
*(uint16_t *)where = (uint16_t)((upper_insn & 0xfbf0) |
((tmp & 0xf000) >> 12) |
((tmp & 0x0800) >> 1));
*((uint16_t *)where + 1) = (uint16_t)((lower_insn & 0x8f00) |
((tmp & 0x0700) << 4) |
(tmp & 0x00ff));
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)) {
printf ("rtl: THM_MOVT_ABS/THM_MOVW_ABS_NC %p @ %p in %s\n",
(void *)*where, where, rtems_rtl_obj_oname (obj));
}
break;
case R_TYPE(THM_JUMP24):
/* same to THM_CALL; insn b.w */
case R_TYPE(THM_CALL):
upper_insn = *(uint16_t *)where;
lower_insn = *((uint16_t *)where + 1);
sign = (upper_insn & (1 << 10)) >> 10;
i1 = ((lower_insn >> 13) & 1) ^ sign ? 0 : 1;
i2 = ((lower_insn >> 11) & 1) ^ sign ? 0 : 1;
tmp = (i1 << 23) | (i2 << 22) | ((upper_insn & 0x3ff) << 12) | ((lower_insn & 0x7ff) << 1);
addend = (tmp | ((sign ? 0 : 1) << 24)) - (1 << 24);
if (isThumb(symvalue)) ;/*Thumb to Thumb call, nothing to care */
else {
if (ELF_R_TYPE(rel->r_info) == R_TYPE(THM_JUMP24)) {
tmp = (tmp + 2) & ~3; /* aligned to 4 bytes only for JUMP24 */
printf("THM_JUMP24 to arm not supported\n");
return false;
}
else {
/* THM_CALL bl-->blx */
lower_insn &=~(1<<12);
}
}
tmp = symvalue + addend;
tmp = tmp - (Elf_Addr)where;
if (((Elf_Sword)tmp > 0x7fffff) || ((Elf_Sword)tmp < -0x800000)) {
printf("THM_CALL/JUMP24 overflow\n");
return false;
}
sign = (tmp >> 24) & 1;
*(uint16_t *)where = (uint16_t)((upper_insn & 0xf800) | (sign << 10) |
((tmp >> 12) & 0x3ff));
*((uint16_t *)where + 1) = (uint16_t)((lower_insn & 0xd000)|
((sign ^ (~(tmp >> 23) & 1)) << 13) |
((sign ^ (~(tmp >> 22) & 1)) << 11) |
((tmp >> 1) & 0x7ff));
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC)){
printf ("rtl: THM_CALL/JUMP24 %p @ %p in %s\n",
(void *)*where, where, rtems_rtl_obj_oname (obj));
}
break;
case R_TYPE(THM_JUMP19):
if (!isThumb(symvalue)) {
printf("THM_JUMP19 to arm not supported\n");
return false;
}
upper_insn = *(uint16_t *)where;
lower_insn = *((uint16_t *)where + 1);
sign = (upper_insn >> 10) & 0x1;
if ((((upper_insn & 0x3f) >> 7) & 0x7) == 0x7) {
printf("THM_JUMP19 failed\n");
return false; /*if cond <3:1> == '111', see Related codings in armv7a manual */
}
i1 = (lower_insn >> 13) & 0x1;
i2 = (lower_insn >> 11) & 0x1;
tmp = ((i2 << 19) | (i1 << 18) | ((upper_insn & 0x3f) << 12) | ((lower_insn & 0x7ff) << 1));
addend = (tmp | ((sign ? 0 : 1) << 20)) - (1 << 20);
tmp = symvalue + addend;
tmp = tmp - (Elf_Addr)where;
if (((Elf_Sword)tmp > 0x7ffffe) || ((Elf_Sword)tmp < -0x800000)) {
rtems_rtl_set_error (EINVAL, "%s: Overflow %ld "
"THM_JUMP19 relocations",
sect->name, (uint32_t) ELF_R_TYPE(rel->r_info));
return false;
}
sign = (tmp >> 20) & 0x1;
i2 = (tmp >> 19) & 0x1;
i1 = (tmp >> 18) & 0x1;
*(uint16_t*)where = (upper_insn & 0xfbc0) | (sign << 10) | ((tmp >> 12) & 0x3f);
*((uint16_t*)where + 1) = (lower_insn & 0xd000) | (i1 << 13) |
(i2 << 11) | ((tmp >> 1) & 0x7ff);
if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
printf ("rtl: THM_JUMP19 %p @ %p in %s\n",
(void *)*where, where, rtems_rtl_obj_oname (obj));
break;
default:
printf ("rtl: reloc unknown: sym = %lu, type = %lu, offset = %p, "
"contents = %p\n",
ELF_R_SYM(rel->r_info), (uint32_t) ELF_R_TYPE(rel->r_info),
(void *)rel->r_offset, (void *)*where);
rtems_rtl_set_error (EINVAL,
"%s: Unsupported relocation type %ld "
"in non-PLT relocations",
sect->name, (uint32_t) ELF_R_TYPE(rel->r_info));
return false;
}
return true;
}
bool
rtems_rtl_elf_unwind_parse (const rtems_rtl_obj_t* obj,
const char* name,
uint32_t flags)
{
/*
* We location the EH sections in section flags.
*/
return false;
}
bool
rtems_rtl_elf_unwind_register (rtems_rtl_obj_t* obj)
{
return true;
}
bool
rtems_rtl_elf_unwind_deregister (rtems_rtl_obj_t* obj)
{
obj->loader = NULL;
return true;
}
/* An exception index table entry. */
typedef struct __EIT_entry
{
_uw fnoffset;
_uw content;
} __EIT_entry;
/* The exception index table location in the base module */
extern __EIT_entry __exidx_start;
extern __EIT_entry __exidx_end;
/*
* A weak reference is in libgcc, provide a real version and provide a way to
* manage loaded modules.
*
* Passed in the return address and a reference to the number of records
* found. We set the start of the exidx data and the number of records.
*/
_Unwind_Ptr __gnu_Unwind_Find_exidx (_Unwind_Ptr return_address,
int* nrec) __attribute__ ((__noinline__,
__used__,
__noclone__));
_Unwind_Ptr __gnu_Unwind_Find_exidx (_Unwind_Ptr return_address,
int* nrec)
{
rtems_rtl_data_t* rtl;
rtems_chain_node* node;
__EIT_entry* exidx_start = &__exidx_start;
__EIT_entry* exidx_end = &__exidx_end;
rtl = rtems_rtl_lock ();
node = rtems_chain_first (&rtl->objects);
while (!rtems_chain_is_tail (&rtl->objects, node)) {
rtems_rtl_obj_t* obj = (rtems_rtl_obj_t*) node;
if (rtems_rtl_obj_text_inside (obj, (void*) return_address)) {
exidx_start = (__EIT_entry*) obj->eh_base;
exidx_end = (__EIT_entry*) (obj->eh_base + obj->eh_size);
break;
}
node = rtems_chain_next (node);
}
rtems_rtl_unlock ();
*nrec = exidx_end - exidx_start;
return (_Unwind_Ptr) exidx_start;
}
