mirror of
https://github.com/limine-bootloader/limine
synced 2024-11-29 11:53:23 +03:00
lib/elf: Add RELR support
This commit is contained in:
mintsuki
parent
5a7052d135
commit
9789274c6d
362
common/lib/elf.c
362
common/lib/elf.c
@ -25,6 +25,9 @@
|
||||
#define DT_RELA 0x00000007
|
||||
#define DT_RELASZ 0x00000008
|
||||
#define DT_RELAENT 0x00000009
|
||||
#define DT_RELR 0x00000024
|
||||
#define DT_RELRSZ 0x00000023
|
||||
#define DT_RELRENT 0x00000025
|
||||
#define DT_SYMTAB 0x00000006
|
||||
#define DT_SYMENT 0x0000000b
|
||||
#define DT_PLTRELSZ 0x00000002
|
||||
@ -56,6 +59,8 @@
|
||||
#define R_RISCV_64 0x00000002
|
||||
#define R_AARCH64_ABS64 0x00000101
|
||||
|
||||
#define R_INTERNAL_RELR 0xfffffff0
|
||||
|
||||
/* Indices into identification array */
|
||||
#define EI_CLASS 4
|
||||
#define EI_DATA 5
|
||||
@ -248,6 +253,20 @@ static bool elf64_apply_relocations(uint8_t *elf, struct elf64_hdr *hdr, void *b
|
||||
panic(true, "elf: phdr_size < sizeof(struct elf64_phdr)");
|
||||
}
|
||||
|
||||
uint64_t symtab_offset = 0;
|
||||
uint64_t symtab_ent = 0;
|
||||
|
||||
uint64_t dt_pltrelsz = 0;
|
||||
uint64_t dt_jmprel = 0;
|
||||
|
||||
uint64_t relr_offset = 0;
|
||||
uint64_t relr_size = 0;
|
||||
uint64_t relr_ent = 0;
|
||||
|
||||
uint64_t rela_offset = 0;
|
||||
uint64_t rela_size = 0;
|
||||
uint64_t rela_ent = 0;
|
||||
|
||||
// Find DYN segment
|
||||
for (uint16_t i = 0; i < hdr->ph_num; i++) {
|
||||
struct elf64_phdr *phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size);
|
||||
@ -255,15 +274,6 @@ static bool elf64_apply_relocations(uint8_t *elf, struct elf64_hdr *hdr, void *b
|
||||
if (phdr->p_type != PT_DYNAMIC)
|
||||
continue;
|
||||
|
||||
uint64_t symtab_offset = 0;
|
||||
uint64_t symtab_ent = 0;
|
||||
|
||||
uint64_t dt_pltrelsz = 0;
|
||||
uint64_t dt_jmprel = 0;
|
||||
|
||||
uint64_t rela_offset = 0;
|
||||
uint64_t rela_size = 0;
|
||||
uint64_t rela_ent = 0;
|
||||
for (uint16_t j = 0; j < phdr->p_filesz / sizeof(struct elf64_dyn); j++) {
|
||||
struct elf64_dyn *dyn = (void *)elf + (phdr->p_offset + j * sizeof(struct elf64_dyn));
|
||||
|
||||
@ -277,6 +287,15 @@ static bool elf64_apply_relocations(uint8_t *elf, struct elf64_hdr *hdr, void *b
|
||||
case DT_RELASZ:
|
||||
rela_size = dyn->d_un;
|
||||
break;
|
||||
case DT_RELR:
|
||||
relr_offset = dyn->d_un;
|
||||
break;
|
||||
case DT_RELRENT:
|
||||
relr_ent = dyn->d_un;
|
||||
break;
|
||||
case DT_RELRSZ:
|
||||
relr_size = dyn->d_un;
|
||||
break;
|
||||
case DT_SYMTAB:
|
||||
symtab_offset = dyn->d_un;
|
||||
break;
|
||||
@ -292,16 +311,16 @@ static bool elf64_apply_relocations(uint8_t *elf, struct elf64_hdr *hdr, void *b
|
||||
}
|
||||
}
|
||||
|
||||
if (rela_offset == 0) {
|
||||
break;
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
if (rela_offset != 0) {
|
||||
if (rela_ent < sizeof(struct elf64_rela)) {
|
||||
panic(true, "elf: sh_entsize < sizeof(struct elf64_rela)");
|
||||
panic(true, "elf: rela_ent < sizeof(struct elf64_rela)");
|
||||
}
|
||||
|
||||
for (uint16_t j = 0; j < hdr->ph_num; j++) {
|
||||
struct elf64_phdr *_phdr = (void *)elf + (hdr->phoff + j * hdr->phdr_size);
|
||||
for (uint16_t i = 0; i < hdr->ph_num; i++) {
|
||||
struct elf64_phdr *_phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size);
|
||||
|
||||
if (_phdr->p_vaddr <= rela_offset && _phdr->p_vaddr + _phdr->p_filesz > rela_offset) {
|
||||
rela_offset -= _phdr->p_vaddr;
|
||||
@ -309,133 +328,196 @@ static bool elf64_apply_relocations(uint8_t *elf, struct elf64_hdr *hdr, void *b
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (symtab_ent < sizeof(struct elf64_sym)) {
|
||||
symtab_offset = 0;
|
||||
}
|
||||
|
||||
if (symtab_offset != 0) {
|
||||
for (uint16_t j = 0; j < hdr->ph_num; j++) {
|
||||
struct elf64_phdr *_phdr = (void *)elf + (hdr->phoff + j * hdr->phdr_size);
|
||||
|
||||
if (_phdr->p_vaddr <= symtab_offset && _phdr->p_vaddr + _phdr->p_filesz > symtab_offset) {
|
||||
symtab_offset -= _phdr->p_vaddr;
|
||||
symtab_offset += _phdr->p_offset;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (dt_pltrelsz == 0) {
|
||||
dt_jmprel = 0;
|
||||
}
|
||||
|
||||
if (dt_jmprel != 0) {
|
||||
for (uint16_t j = 0; j < hdr->ph_num; j++) {
|
||||
struct elf64_phdr *_phdr = (void *)elf + (hdr->phoff + j * hdr->phdr_size);
|
||||
|
||||
if (_phdr->p_vaddr <= dt_jmprel && _phdr->p_vaddr + _phdr->p_filesz > dt_jmprel) {
|
||||
dt_jmprel -= _phdr->p_vaddr;
|
||||
dt_jmprel += _phdr->p_offset;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
size_t relocs_i = rela_size / rela_ent;
|
||||
if (dt_jmprel != 0) {
|
||||
relocs_i += dt_pltrelsz / rela_ent;
|
||||
}
|
||||
struct elf64_rela **relocs = ext_mem_alloc(relocs_i * sizeof(struct elf64_rela *));
|
||||
|
||||
for (uint64_t j = 0, offset = 0; offset < rela_size; offset += rela_ent) {
|
||||
relocs[j++] = (void *)elf + (rela_offset + offset);
|
||||
}
|
||||
|
||||
if (dt_jmprel != 0) {
|
||||
for (uint64_t j = rela_size / rela_ent, offset = 0; offset < dt_pltrelsz; offset += rela_ent) {
|
||||
relocs[j++] = (void *)elf + (dt_jmprel + offset);
|
||||
}
|
||||
}
|
||||
|
||||
for (size_t j = 0; j < relocs_i; j++) {
|
||||
struct elf64_rela *relocation = relocs[j];
|
||||
|
||||
// Relocation is before buffer
|
||||
if (relocation->r_addr < vaddr)
|
||||
continue;
|
||||
|
||||
// Relocation is after buffer
|
||||
if (vaddr + size < relocation->r_addr + 8)
|
||||
continue;
|
||||
|
||||
// It's inside it, calculate where it is
|
||||
uint64_t *ptr = (uint64_t *)((buffer - vaddr) + relocation->r_addr);
|
||||
|
||||
switch (relocation->r_info) {
|
||||
#if defined (__x86_64__) || defined (__i386__)
|
||||
case R_X86_64_NONE:
|
||||
#elif defined (__aarch64__)
|
||||
case R_AARCH64_NONE:
|
||||
#elif defined (__riscv64)
|
||||
case R_RISCV_NONE:
|
||||
#endif
|
||||
{
|
||||
break;
|
||||
}
|
||||
#if defined (__x86_64__) || defined (__i386__)
|
||||
case R_X86_64_RELATIVE:
|
||||
#elif defined (__aarch64__)
|
||||
case R_AARCH64_RELATIVE:
|
||||
#elif defined (__riscv64)
|
||||
case R_RISCV_RELATIVE:
|
||||
#endif
|
||||
{
|
||||
*ptr = slide + relocation->r_addend;
|
||||
break;
|
||||
}
|
||||
#if defined (__x86_64__) || defined (__i386__)
|
||||
case R_X86_64_GLOB_DAT:
|
||||
case R_X86_64_JUMP_SLOT:
|
||||
#elif defined (__aarch64__)
|
||||
case R_AARCH64_GLOB_DAT:
|
||||
case R_AARCH64_JUMP_SLOT:
|
||||
#elif defined (__riscv64)
|
||||
case R_RISCV_JUMP_SLOT:
|
||||
#endif
|
||||
{
|
||||
struct elf64_sym *s = (void *)elf + symtab_offset + symtab_ent * relocation->r_symbol;
|
||||
*ptr = slide + s->st_value
|
||||
#if defined (__aarch64__)
|
||||
+ relocation->r_addend
|
||||
#endif
|
||||
;
|
||||
break;
|
||||
}
|
||||
#if defined (__x86_64__) || defined (__i386__)
|
||||
case R_X86_64_64:
|
||||
#elif defined (__aarch64__)
|
||||
case R_AARCH64_ABS64:
|
||||
#elif defined (__riscv64)
|
||||
case R_RISCV_64:
|
||||
#endif
|
||||
{
|
||||
struct elf64_sym *s = (void *)elf + symtab_offset + symtab_ent * relocation->r_symbol;
|
||||
*ptr = slide + s->st_value + relocation->r_addend;
|
||||
break;
|
||||
}
|
||||
default: {
|
||||
print("elf: Unknown RELA type: %x\n", relocation->r_info);
|
||||
return false;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
pmm_free(relocs, relocs_i * sizeof(struct elf64_rela *));
|
||||
|
||||
break;
|
||||
}
|
||||
|
||||
if (relr_offset != 0) {
|
||||
if (relr_ent != 8) {
|
||||
panic(true, "elf: relr_ent != 8");
|
||||
}
|
||||
|
||||
for (uint16_t i = 0; i < hdr->ph_num; i++) {
|
||||
struct elf64_phdr *_phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size);
|
||||
|
||||
if (_phdr->p_vaddr <= relr_offset && _phdr->p_vaddr + _phdr->p_filesz > relr_offset) {
|
||||
relr_offset -= _phdr->p_vaddr;
|
||||
relr_offset += _phdr->p_offset;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (symtab_offset != 0) {
|
||||
if (symtab_ent < sizeof(struct elf64_sym)) {
|
||||
panic(true, "elf: symtab_ent < sizeof(struct elf64_sym)");
|
||||
}
|
||||
|
||||
for (uint16_t i = 0; i < hdr->ph_num; i++) {
|
||||
struct elf64_phdr *_phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size);
|
||||
|
||||
if (_phdr->p_vaddr <= symtab_offset && _phdr->p_vaddr + _phdr->p_filesz > symtab_offset) {
|
||||
symtab_offset -= _phdr->p_vaddr;
|
||||
symtab_offset += _phdr->p_offset;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (dt_jmprel != 0) {
|
||||
if (rela_ent < sizeof(struct elf64_rela)) {
|
||||
panic(true, "elf: rela_ent < sizeof(struct elf64_rela)");
|
||||
}
|
||||
|
||||
for (uint16_t i = 0; i < hdr->ph_num; i++) {
|
||||
struct elf64_phdr *_phdr = (void *)elf + (hdr->phoff + i * hdr->phdr_size);
|
||||
|
||||
if (_phdr->p_vaddr <= dt_jmprel && _phdr->p_vaddr + _phdr->p_filesz > dt_jmprel) {
|
||||
dt_jmprel -= _phdr->p_vaddr;
|
||||
dt_jmprel += _phdr->p_offset;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
size_t relocs_i = 0;
|
||||
if (relr_offset != 0) {
|
||||
for (size_t i = 0; i < relr_size / relr_ent; i++) {
|
||||
uint64_t entry = *((uint64_t *)(elf + relr_offset + i * relr_ent));
|
||||
|
||||
if ((entry & 1) == 0) {
|
||||
relocs_i++;
|
||||
} else {
|
||||
relocs_i += __builtin_popcount(entry) - 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
size_t relr_count = relocs_i;
|
||||
if (rela_offset != 0) {
|
||||
relocs_i += rela_size / rela_ent;
|
||||
}
|
||||
if (dt_jmprel != 0) {
|
||||
relocs_i += dt_pltrelsz / rela_ent;
|
||||
}
|
||||
struct elf64_rela **relocs = ext_mem_alloc(relocs_i * sizeof(struct elf64_rela *));
|
||||
|
||||
if (relr_offset != 0) {
|
||||
size_t relr_i;
|
||||
for (relr_i = 0; relr_i < relr_count; relr_i++) {
|
||||
relocs[relr_i] = ext_mem_alloc(sizeof(struct elf64_rela));
|
||||
relocs[relr_i]->r_info = R_INTERNAL_RELR;
|
||||
}
|
||||
|
||||
// This logic is partially lifted from https://maskray.me/blog/2021-10-31-relative-relocations-and-relr
|
||||
uint64_t where;
|
||||
relr_i = 0;
|
||||
for (size_t i = 0; i < relr_size / relr_ent; i++) {
|
||||
uint64_t entry = *((uint64_t *)(elf + relr_offset + i * relr_ent));
|
||||
|
||||
if ((entry & 1) == 0) {
|
||||
where = entry;
|
||||
relocs[relr_i++]->r_addr = where;
|
||||
where += 8;
|
||||
} else {
|
||||
for (size_t j = 0; (entry >>= 1) != 0; j++) {
|
||||
if ((entry & 1) != 0) {
|
||||
relocs[relr_i++]->r_addr = where + j * 8;
|
||||
}
|
||||
}
|
||||
where += 63 * 8;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (rela_offset != 0) {
|
||||
for (uint64_t i = relr_count, offset = 0; offset < rela_size; offset += rela_ent) {
|
||||
relocs[i++] = (void *)elf + (rela_offset + offset);
|
||||
}
|
||||
}
|
||||
|
||||
if (dt_jmprel != 0) {
|
||||
for (uint64_t i = relr_count + rela_size / rela_ent, offset = 0; offset < dt_pltrelsz; offset += rela_ent) {
|
||||
relocs[i++] = (void *)elf + (dt_jmprel + offset);
|
||||
}
|
||||
}
|
||||
|
||||
for (size_t i = 0; i < relocs_i; i++) {
|
||||
struct elf64_rela *relocation = relocs[i];
|
||||
|
||||
// Relocation is before buffer
|
||||
if (relocation->r_addr < vaddr)
|
||||
continue;
|
||||
|
||||
// Relocation is after buffer
|
||||
if (vaddr + size < relocation->r_addr + 8)
|
||||
continue;
|
||||
|
||||
// It's inside it, calculate where it is
|
||||
uint64_t *ptr = (uint64_t *)((buffer - vaddr) + relocation->r_addr);
|
||||
|
||||
switch (relocation->r_info) {
|
||||
#if defined (__x86_64__) || defined (__i386__)
|
||||
case R_X86_64_NONE:
|
||||
#elif defined (__aarch64__)
|
||||
case R_AARCH64_NONE:
|
||||
#elif defined (__riscv64)
|
||||
case R_RISCV_NONE:
|
||||
#endif
|
||||
{
|
||||
break;
|
||||
}
|
||||
#if defined (__x86_64__) || defined (__i386__)
|
||||
case R_X86_64_RELATIVE:
|
||||
#elif defined (__aarch64__)
|
||||
case R_AARCH64_RELATIVE:
|
||||
#elif defined (__riscv64)
|
||||
case R_RISCV_RELATIVE:
|
||||
#endif
|
||||
{
|
||||
*ptr = slide + relocation->r_addend;
|
||||
break;
|
||||
}
|
||||
case R_INTERNAL_RELR:
|
||||
{
|
||||
*ptr += slide;
|
||||
break;
|
||||
}
|
||||
#if defined (__x86_64__) || defined (__i386__)
|
||||
case R_X86_64_GLOB_DAT:
|
||||
case R_X86_64_JUMP_SLOT:
|
||||
#elif defined (__aarch64__)
|
||||
case R_AARCH64_GLOB_DAT:
|
||||
case R_AARCH64_JUMP_SLOT:
|
||||
#elif defined (__riscv64)
|
||||
case R_RISCV_JUMP_SLOT:
|
||||
#endif
|
||||
{
|
||||
struct elf64_sym *s = (void *)elf + symtab_offset + symtab_ent * relocation->r_symbol;
|
||||
*ptr = slide + s->st_value
|
||||
#if defined (__aarch64__)
|
||||
+ relocation->r_addend
|
||||
#endif
|
||||
;
|
||||
break;
|
||||
}
|
||||
#if defined (__x86_64__) || defined (__i386__)
|
||||
case R_X86_64_64:
|
||||
#elif defined (__aarch64__)
|
||||
case R_AARCH64_ABS64:
|
||||
#elif defined (__riscv64)
|
||||
case R_RISCV_64:
|
||||
#endif
|
||||
{
|
||||
struct elf64_sym *s = (void *)elf + symtab_offset + symtab_ent * relocation->r_symbol;
|
||||
*ptr = slide + s->st_value + relocation->r_addend;
|
||||
break;
|
||||
}
|
||||
default: {
|
||||
panic(true, "elf: Unknown relocation type: %x", relocation->r_info);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
pmm_free(relocs, relocs_i * sizeof(struct elf64_rela *));
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user