coreboot-kgpe-d16/util/cbfstool/rmodule.c

922 lines
22 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "elfparsing.h"
#include "rmodule.h"
#include <commonlib/rmodule-defs.h>
/*
* Architecture specific support operations.
*/
static int valid_reloc_386(Elf64_Rela *rel)
{
int type;
type = ELF64_R_TYPE(rel->r_info);
/* Only these 2 relocations are expected to be found. */
return (type == R_386_32 || type == R_386_PC32);
}
static int should_emit_386(Elf64_Rela *rel)
{
int type;
type = ELF64_R_TYPE(rel->r_info);
/* R_386_32 relocations are absolute. Must emit these. */
return (type == R_386_32);
}
static int valid_reloc_amd64(Elf64_Rela *rel)
{
int type;
type = ELF64_R_TYPE(rel->r_info);
/*
* Relocation R_AMD64_32S is not allowed. It can only be safely used in protected mode,
* and when the address pointed to is below 2 GiB in long mode.
* Using it in assembly operations will break compilation with error:
* E: Invalid reloc type: 11
*/
/* Only these 5 relocations are expected to be found. */
return (type == R_AMD64_64 ||
type == R_AMD64_PC64 ||
type == R_AMD64_32 ||
type == R_AMD64_PC32 ||
/*
* binutils 2.31 introduced R_AMD64_PLT32 for non local
* functions. As we don't care about procedure linkage
* table entries handle it as R_X86_64_PC32.
*/
type == R_AMD64_PLT32);
}
static int should_emit_amd64(Elf64_Rela *rel)
{
int type;
type = ELF64_R_TYPE(rel->r_info);
/* Only emit absolute relocations */
return (type == R_AMD64_64 ||
type == R_AMD64_32);
}
static int valid_reloc_arm(Elf64_Rela *rel)
{
int type;
type = ELF64_R_TYPE(rel->r_info);
/* Only these 6 relocations are expected to be found. */
return (type == R_ARM_ABS32 || type == R_ARM_THM_PC22 ||
type == R_ARM_THM_JUMP24 || type == R_ARM_V4BX ||
type == R_ARM_CALL || type == R_ARM_JUMP24);
}
static int should_emit_arm(Elf64_Rela *rel)
{
int type;
type = ELF64_R_TYPE(rel->r_info);
/* R_ARM_ABS32 relocations are absolute. Must emit these. */
return (type == R_ARM_ABS32);
}
static int valid_reloc_aarch64(Elf64_Rela *rel)
{
int type;
type = ELF64_R_TYPE(rel->r_info);
return (type == R_AARCH64_ADR_PREL_PG_HI21 ||
type == R_AARCH64_ADD_ABS_LO12_NC ||
type == R_AARCH64_LDST8_ABS_LO12_NC ||
type == R_AARCH64_CONDBR19 ||
type == R_AARCH64_JUMP26 ||
type == R_AARCH64_LDST32_ABS_LO12_NC ||
type == R_AARCH64_LDST64_ABS_LO12_NC ||
type == R_AARCH64_CALL26 ||
type == R_AARCH64_ABS64 ||
type == R_AARCH64_LD_PREL_LO19 ||
type == R_AARCH64_ADR_PREL_LO21);
}
static int should_emit_aarch64(Elf64_Rela *rel)
{
int type;
type = ELF64_R_TYPE(rel->r_info);
return (type == R_AARCH64_ABS64);
}
static const struct arch_ops reloc_ops[] = {
{
.arch = EM_386,
.valid_type = valid_reloc_386,
.should_emit = should_emit_386,
},
{
.arch = EM_X86_64,
.valid_type = valid_reloc_amd64,
.should_emit = should_emit_amd64,
},
{
.arch = EM_ARM,
.valid_type = valid_reloc_arm,
.should_emit = should_emit_arm,
},
{
.arch = EM_AARCH64,
.valid_type = valid_reloc_aarch64,
.should_emit = should_emit_aarch64,
},
};
static int relocation_for_absolute_symbol(struct rmod_context *ctx, Elf64_Rela *r)
{
Elf64_Sym *s = &ctx->pelf.syms[ELF64_R_SYM(r->r_info)];
if (s->st_shndx == SHN_ABS) {
DEBUG("Omitting relocation for absolute symbol: %s\n",
&ctx->strtab[s->st_name]);
return 1;
}
return 0;
}
static int relocation_for_weak_extern_symbols(struct rmod_context *ctx, Elf64_Rela *r)
{
Elf64_Sym *s = &ctx->pelf.syms[ELF64_R_SYM(r->r_info)];
if (ELF64_ST_BIND(s->st_info) == STB_WEAK && ELF64_ST_TYPE(s->st_info) == STT_NOTYPE) {
DEBUG("Omitting relocation for undefined extern: %s\n",
&ctx->strtab[s->st_name]);
return 1;
}
return 0;
}
/*
* Relocation processing loops.
*/
static int for_each_reloc(struct rmod_context *ctx, struct reloc_filter *f,
int do_emit)
{
Elf64_Half i;
struct parsed_elf *pelf = &ctx->pelf;
for (i = 0; i < pelf->ehdr.e_shnum; i++) {
Elf64_Shdr *shdr;
Elf64_Rela *relocs;
Elf64_Xword nrelocs;
Elf64_Xword j;
relocs = pelf->relocs[i];
/* No relocations in this section. */
if (relocs == NULL)
continue;
shdr = &pelf->shdr[i];
nrelocs = shdr->sh_size / shdr->sh_entsize;
for (j = 0; j < nrelocs; j++) {
int filter_emit = 1;
Elf64_Rela *r = &relocs[j];
if (!ctx->ops->valid_type(r)) {
ERROR("Invalid reloc type: %u\n",
(unsigned int)ELF64_R_TYPE(r->r_info));
if ((ctx->ops->arch == EM_X86_64) &&
(ELF64_R_TYPE(r->r_info) == R_AMD64_32S))
ERROR("Illegal use of 32bit sign extended addressing at offset 0x%x\n",
(unsigned int)r->r_offset);
return -1;
}
if (relocation_for_absolute_symbol(ctx, r))
continue;
if (relocation_for_weak_extern_symbols(ctx, r))
continue;
/* Allow the provided filter to have precedence. */
if (f != NULL) {
filter_emit = f->filter(f, r);
if (filter_emit < 0)
return filter_emit;
}
if (filter_emit && ctx->ops->should_emit(r)) {
int n = ctx->nrelocs;
if (do_emit)
ctx->emitted_relocs[n] = r->r_offset;
ctx->nrelocs++;
}
}
}
return 0;
}
static int find_program_segment(struct rmod_context *ctx)
{
int i;
int nsegments;
struct parsed_elf *pelf;
Elf64_Phdr *phdr = NULL;
pelf = &ctx->pelf;
/* There should only be a single loadable segment. */
nsegments = 0;
for (i = 0; i < pelf->ehdr.e_phnum; i++) {
if (pelf->phdr[i].p_type != PT_LOAD)
continue;
if (!phdr)
phdr = &pelf->phdr[i];
nsegments++;
}
if (nsegments == 0) {
ERROR("No loadable segment found.\n");
return -1;
}
INFO("Segment at 0x%0llx, file size 0x%0llx, mem size 0x%0llx.\n",
(long long)phdr->p_vaddr, (long long)phdr->p_filesz,
(long long)phdr->p_memsz);
ctx->phdr = phdr;
ctx->nsegments = nsegments;
return 0;
}
static int
filter_relocation_sections(struct rmod_context *ctx)
{
int i, j;
const char *shstrtab;
struct parsed_elf *pelf;
const Elf64_Phdr *phdr;
pelf = &ctx->pelf;
shstrtab = buffer_get(pelf->strtabs[pelf->ehdr.e_shstrndx]);
/*
* Find all relocation sections that contain relocation entries
* for sections that fall within the bounds of the segments. For
* easier processing the pointer to the relocation array for the
* sections that don't fall within the loadable program are NULL'd
* out.
*/
for (i = 0; i < pelf->ehdr.e_shnum; i++) {
Elf64_Shdr *shdr;
Elf64_Word sh_info;
const char *section_name;
shdr = &pelf->shdr[i];
/* Ignore non-relocation sections. */
if (shdr->sh_type != SHT_RELA && shdr->sh_type != SHT_REL)
continue;
/* Obtain section which relocations apply. */
sh_info = shdr->sh_info;
shdr = &pelf->shdr[sh_info];
section_name = &shstrtab[shdr->sh_name];
DEBUG("Relocation section found for '%s' section.\n",
section_name);
/* Do not process relocations for debug sections. */
if (strstr(section_name, ".debug") != NULL) {
pelf->relocs[i] = NULL;
continue;
}
/*
* If relocations apply to a non program section ignore the
* relocations for future processing.
*/
if (shdr->sh_type != SHT_PROGBITS) {
pelf->relocs[i] = NULL;
continue;
}
for (j = 0; j < pelf->ehdr.e_phnum; j++) {
phdr = &pelf->phdr[j];
if (phdr->p_type == PT_LOAD &&
shdr->sh_addr >= phdr->p_vaddr &&
((shdr->sh_addr + shdr->sh_size) <=
(phdr->p_vaddr + phdr->p_memsz)))
break;
}
if (j == pelf->ehdr.e_phnum) {
ERROR("Relocations being applied to section %d not "
"within segments region.\n", sh_info);
pelf->relocs[i] = NULL;
return -1;
}
}
return 0;
}
static int vaddr_cmp(const void *a, const void *b)
{
const Elf64_Addr *pa = a;
const Elf64_Addr *pb = b;
if (*pa < *pb)
return -1;
if (*pa > *pb)
return 1;
return 0;
}
int rmodule_collect_relocations(struct rmod_context *ctx,
struct reloc_filter *f)
{
Elf64_Xword nrelocs;
/*
* The relocs array in the pelf should only contain relocations that
* apply to the program. Count the number relocations. Then collect
* them into the allocated buffer.
*/
if (for_each_reloc(ctx, f, 0))
return -1;
nrelocs = ctx->nrelocs;
INFO("%" PRIu64 " relocations to be emitted.\n", nrelocs);
if (!nrelocs)
return 0;
/* Reset the counter for indexing into the array. */
ctx->nrelocs = 0;
ctx->emitted_relocs = calloc(nrelocs, sizeof(Elf64_Addr));
/* Write out the relocations into the emitted_relocs array. */
if (for_each_reloc(ctx, f, 1))
return -1;
if (ctx->nrelocs != nrelocs) {
ERROR("Mismatch counted and emitted relocations: %zu vs %zu.\n",
(size_t)nrelocs, (size_t)ctx->nrelocs);
return -1;
}
/* Sort the relocations by their address. */
qsort(ctx->emitted_relocs, nrelocs, sizeof(Elf64_Addr), vaddr_cmp);
return 0;
}
static int
populate_sym(struct rmod_context *ctx, const char *sym_name, Elf64_Addr *addr,
int nsyms, int optional)
{
int i;
Elf64_Sym *syms;
syms = ctx->pelf.syms;
for (i = 0; i < nsyms; i++) {
if (syms[i].st_name == 0)
continue;
if (strcmp(sym_name, &ctx->strtab[syms[i].st_name]))
continue;
DEBUG("%s -> 0x%llx\n", sym_name, (long long)syms[i].st_value);
*addr = syms[i].st_value;
return 0;
}
if (optional) {
DEBUG("optional symbol '%s' not found.\n", sym_name);
*addr = 0;
return 0;
}
ERROR("symbol '%s' not found.\n", sym_name);
return -1;
}
static int populate_rmodule_info(struct rmod_context *ctx)
{
int i;
struct parsed_elf *pelf;
Elf64_Ehdr *ehdr;
int nsyms;
pelf = &ctx->pelf;
ehdr = &pelf->ehdr;
/* Determine number of symbols. */
nsyms = 0;
for (i = 0; i < ehdr->e_shnum; i++) {
if (pelf->shdr[i].sh_type != SHT_SYMTAB)
continue;
nsyms = pelf->shdr[i].sh_size / pelf->shdr[i].sh_entsize;
break;
}
if (populate_sym(ctx, "_rmodule_params", &ctx->parameters_begin, nsyms, 1))
return -1;
if (populate_sym(ctx, "_ermodule_params", &ctx->parameters_end, nsyms, 1))
return -1;
if (populate_sym(ctx, "_bss", &ctx->bss_begin, nsyms, 0))
return -1;
if (populate_sym(ctx, "_ebss", &ctx->bss_end, nsyms, 0))
return -1;
return 0;
}
static int
add_section(struct elf_writer *ew, struct buffer *data, const char *name,
Elf64_Addr addr, Elf64_Word size)
{
Elf64_Shdr shdr;
int ret;
memset(&shdr, 0, sizeof(shdr));
if (data != NULL) {
shdr.sh_type = SHT_PROGBITS;
shdr.sh_flags = SHF_ALLOC | SHF_WRITE | SHF_EXECINSTR;
} else {
shdr.sh_type = SHT_NOBITS;
shdr.sh_flags = SHF_ALLOC;
}
shdr.sh_addr = addr;
shdr.sh_offset = addr;
shdr.sh_size = size;
ret = elf_writer_add_section(ew, &shdr, data, name);
if (ret)
ERROR("Could not add '%s' section.\n", name);
return ret;
}
static int
write_elf(const struct rmod_context *ctx, const struct buffer *in,
struct buffer *out)
{
int ret;
int bit64;
size_t loc;
size_t rmod_data_size;
struct elf_writer *ew;
struct buffer rmod_data;
struct buffer rmod_header;
struct buffer program;
struct buffer relocs;
Elf64_Xword total_size;
Elf64_Addr addr;
Elf64_Ehdr ehdr;
if (ctx->nsegments != 1) {
ERROR("Multiple loadable segments is not supported.\n");
return -1;
}
bit64 = ctx->pelf.ehdr.e_ident[EI_CLASS] == ELFCLASS64;
/*
* 3 sections will be added to the ELF file.
* +------------------+
* | rmodule header |
* +------------------+
* | program |
* +------------------+
* | relocations |
* +------------------+
*/
/* Create buffer for header and relocations. */
rmod_data_size = sizeof(struct rmodule_header);
if (bit64)
rmod_data_size += ctx->nrelocs * sizeof(Elf64_Addr);
else
rmod_data_size += ctx->nrelocs * sizeof(Elf32_Addr);
if (buffer_create(&rmod_data, rmod_data_size, "rmod"))
return -1;
buffer_splice(&rmod_header, &rmod_data,
0, sizeof(struct rmodule_header));
buffer_clone(&relocs, &rmod_data);
buffer_seek(&relocs, sizeof(struct rmodule_header));
/* Reset current location. */
buffer_set_size(&rmod_header, 0);
buffer_set_size(&relocs, 0);
/* Program contents. */
buffer_splice(&program, in, ctx->phdr->p_offset, ctx->phdr->p_filesz);
/* Create ELF writer. Set entry point to 0 to match section offsets. */
memcpy(&ehdr, &ctx->pelf.ehdr, sizeof(ehdr));
ehdr.e_entry = 0;
ew = elf_writer_init(&ehdr);
if (ew == NULL) {
ERROR("Failed to create ELF writer.\n");
buffer_delete(&rmod_data);
return -1;
}
/* Write out rmodule_header. */
ctx->xdr->put16(&rmod_header, RMODULE_MAGIC);
ctx->xdr->put8(&rmod_header, RMODULE_VERSION_1);
ctx->xdr->put8(&rmod_header, 0);
/* payload_begin_offset */
loc = sizeof(struct rmodule_header);
ctx->xdr->put32(&rmod_header, loc);
/* payload_end_offset */
loc += ctx->phdr->p_filesz;
ctx->xdr->put32(&rmod_header, loc);
/* relocations_begin_offset */
ctx->xdr->put32(&rmod_header, loc);
/* relocations_end_offset */
if (bit64)
loc += ctx->nrelocs * sizeof(Elf64_Addr);
else
loc += ctx->nrelocs * sizeof(Elf32_Addr);
ctx->xdr->put32(&rmod_header, loc);
/* module_link_start_address */
ctx->xdr->put32(&rmod_header, ctx->phdr->p_vaddr);
/* module_program_size */
ctx->xdr->put32(&rmod_header, ctx->phdr->p_memsz);
/* module_entry_point */
ctx->xdr->put32(&rmod_header, ctx->pelf.ehdr.e_entry);
/* parameters_begin */
ctx->xdr->put32(&rmod_header, ctx->parameters_begin);
/* parameters_end */
ctx->xdr->put32(&rmod_header, ctx->parameters_end);
/* bss_begin */
ctx->xdr->put32(&rmod_header, ctx->bss_begin);
/* bss_end */
ctx->xdr->put32(&rmod_header, ctx->bss_end);
/* padding[4] */
ctx->xdr->put32(&rmod_header, 0);
ctx->xdr->put32(&rmod_header, 0);
ctx->xdr->put32(&rmod_header, 0);
ctx->xdr->put32(&rmod_header, 0);
/* Write the relocations. */
for (unsigned i = 0; i < ctx->nrelocs; i++) {
if (bit64)
ctx->xdr->put64(&relocs, ctx->emitted_relocs[i]);
else
ctx->xdr->put32(&relocs, ctx->emitted_relocs[i]);
}
total_size = 0;
addr = 0;
/*
* There are 2 cases to deal with. The program has a large NOBITS
* section and the relocations can fit entirely within occupied memory
* region for the program. The other is that the relocations increase
* the memory footprint of the program if it was loaded directly into
* the region it would run. The rmodule header is a fixed cost that
* is considered a part of the program.
*/
total_size += buffer_size(&rmod_header);
if (buffer_size(&relocs) + ctx->phdr->p_filesz > ctx->phdr->p_memsz) {
total_size += buffer_size(&relocs);
total_size += ctx->phdr->p_filesz;
} else {
total_size += ctx->phdr->p_memsz;
}
ret = add_section(ew, &rmod_header, ".header", addr,
buffer_size(&rmod_header));
if (ret < 0)
goto out;
addr += buffer_size(&rmod_header);
ret = add_section(ew, &program, ".program", addr, ctx->phdr->p_filesz);
if (ret < 0)
goto out;
addr += ctx->phdr->p_filesz;
if (ctx->nrelocs) {
ret = add_section(ew, &relocs, ".relocs", addr,
buffer_size(&relocs));
if (ret < 0)
goto out;
addr += buffer_size(&relocs);
}
if (total_size != addr) {
ret = add_section(ew, NULL, ".empty", addr, total_size - addr);
if (ret < 0)
goto out;
}
/*
* Ensure last section has a memory usage that meets the required
* total size of the program in memory.
*/
ret = elf_writer_serialize(ew, out);
if (ret < 0)
ERROR("Failed to serialize ELF to buffer.\n");
out:
buffer_delete(&rmod_data);
elf_writer_destroy(ew);
return ret;
}
int rmodule_init(struct rmod_context *ctx, const struct buffer *elfin)
{
struct parsed_elf *pelf;
size_t i;
int ret;
ret = -1;
memset(ctx, 0, sizeof(*ctx));
pelf = &ctx->pelf;
if (parse_elf(elfin, pelf, ELF_PARSE_ALL)) {
ERROR("Couldn't parse ELF!\n");
return -1;
}
/* Only allow executables to be turned into rmodules. */
if (pelf->ehdr.e_type != ET_EXEC) {
ERROR("ELF is not an executable: %u.\n", pelf->ehdr.e_type);
goto out;
}
/* Determine if architecture is supported. */
for (i = 0; i < ARRAY_SIZE(reloc_ops); i++) {
if (reloc_ops[i].arch == pelf->ehdr.e_machine) {
ctx->ops = &reloc_ops[i];
break;
}
}
if (ctx->ops == NULL) {
ERROR("ELF is unsupported arch: %u.\n", pelf->ehdr.e_machine);
goto out;
}
/* Set the endian ops. */
if (ctx->pelf.ehdr.e_ident[EI_DATA] == ELFDATA2MSB)
ctx->xdr = &xdr_be;
else
ctx->xdr = &xdr_le;
/* Obtain the string table. */
for (i = 0; i < pelf->ehdr.e_shnum; i++) {
if (pelf->strtabs[i] == NULL)
continue;
/* Don't use the section headers' string table. */
if (i == pelf->ehdr.e_shstrndx)
continue;
ctx->strtab = buffer_get(pelf->strtabs[i]);
break;
}
if (ctx->strtab == NULL) {
ERROR("No string table found.\n");
return -1;
}
if (find_program_segment(ctx))
goto out;
if (filter_relocation_sections(ctx))
goto out;
ret = 0;
out:
return ret;
}
void rmodule_cleanup(struct rmod_context *ctx)
{
free(ctx->emitted_relocs);
parsed_elf_destroy(&ctx->pelf);
}
int rmodule_create(const struct buffer *elfin, struct buffer *elfout)
{
struct rmod_context ctx;
int ret = -1;
if (rmodule_init(&ctx, elfin))
goto out;
if (rmodule_collect_relocations(&ctx, NULL))
goto out;
if (populate_rmodule_info(&ctx))
goto out;
if (write_elf(&ctx, elfin, elfout))
goto out;
ret = 0;
out:
rmodule_cleanup(&ctx);
return ret;
}
static void rmod_deserialize(struct rmodule_header *rmod, struct buffer *buff,
struct xdr *xdr)
{
rmod->magic = xdr->get16(buff);
rmod->version = xdr->get8(buff);
rmod->type = xdr->get8(buff);
rmod->payload_begin_offset = xdr->get32(buff);
rmod->payload_end_offset = xdr->get32(buff);
rmod->relocations_begin_offset = xdr->get32(buff);
rmod->relocations_end_offset = xdr->get32(buff);
rmod->module_link_start_address = xdr->get32(buff);
rmod->module_program_size = xdr->get32(buff);
rmod->module_entry_point = xdr->get32(buff);
rmod->parameters_begin = xdr->get32(buff);
rmod->parameters_end = xdr->get32(buff);
rmod->bss_begin = xdr->get32(buff);
rmod->bss_end = xdr->get32(buff);
rmod->padding[0] = xdr->get32(buff);
rmod->padding[1] = xdr->get32(buff);
rmod->padding[2] = xdr->get32(buff);
rmod->padding[3] = xdr->get32(buff);
}
int rmodule_stage_to_elf(Elf64_Ehdr *ehdr, struct buffer *buff)
{
struct buffer reader;
struct buffer elf_out;
struct rmodule_header rmod;
struct xdr *xdr;
struct elf_writer *ew;
Elf64_Shdr shdr;
int bit64;
size_t payload_sz;
const char *section_name = ".program";
const size_t input_sz = buffer_size(buff);
buffer_clone(&reader, buff);
xdr = (ehdr->e_ident[EI_DATA] == ELFDATA2MSB) ? &xdr_be : &xdr_le;
bit64 = ehdr->e_ident[EI_CLASS] == ELFCLASS64;
rmod_deserialize(&rmod, &reader, xdr);
/* Indicate that file is not an rmodule if initial checks fail. */
if (rmod.magic != RMODULE_MAGIC)
return 1;
if (rmod.version != RMODULE_VERSION_1)
return 1;
if (rmod.payload_begin_offset > input_sz ||
rmod.payload_end_offset > input_sz ||
rmod.relocations_begin_offset > input_sz ||
rmod.relocations_end_offset > input_sz) {
ERROR("Rmodule fields out of bounds.\n");
return -1;
}
ehdr->e_entry = rmod.module_entry_point;
ew = elf_writer_init(ehdr);
if (ew == NULL)
return -1;
payload_sz = rmod.payload_end_offset - rmod.payload_begin_offset;
memset(&shdr, 0, sizeof(shdr));
shdr.sh_type = SHT_PROGBITS;
shdr.sh_flags = SHF_WRITE | SHF_ALLOC | SHF_EXECINSTR;
shdr.sh_addr = rmod.module_link_start_address;
shdr.sh_size = payload_sz;
buffer_splice(&reader, buff, rmod.payload_begin_offset, payload_sz);
if (elf_writer_add_section(ew, &shdr, &reader, section_name)) {
ERROR("Unable to add ELF section: %s\n", section_name);
elf_writer_destroy(ew);
return -1;
}
if (payload_sz != rmod.module_program_size) {
struct buffer b;
buffer_init(&b, NULL, NULL, 0);
memset(&shdr, 0, sizeof(shdr));
shdr.sh_type = SHT_NOBITS;
shdr.sh_flags = SHF_WRITE | SHF_ALLOC;
shdr.sh_addr = rmod.module_link_start_address + payload_sz;
shdr.sh_size = rmod.module_program_size - payload_sz;
if (elf_writer_add_section(ew, &shdr, &b, ".empty")) {
ERROR("Unable to add ELF section: .empty\n");
elf_writer_destroy(ew);
return -1;
}
}
/* Provide a section symbol so the relcoations can reference that. */
if (elf_writer_add_symbol(ew, section_name, section_name, shdr.sh_addr,
0, STB_LOCAL, STT_SECTION)) {
ERROR("Unable to add section symbol to ELF.\n");
elf_writer_destroy(ew);
return -1;
}
/* Add symbols for the parameters if they are non-zero. */
if (rmod.parameters_begin != rmod.parameters_end) {
int ret = 0;
ret |= elf_writer_add_symbol(ew, "_rmodule_params",
section_name,
rmod.parameters_begin, 0,
STB_GLOBAL, STT_NOTYPE);
ret |= elf_writer_add_symbol(ew, "_ermodule_params",
section_name,
rmod.parameters_end, 0,
STB_GLOBAL, STT_NOTYPE);
if (ret != 0) {
ERROR("Unable to add module params symbols to ELF\n");
elf_writer_destroy(ew);
return -1;
}
}
if (elf_writer_add_symbol(ew, "_bss", section_name, rmod.bss_begin, 0,
STB_GLOBAL, STT_NOTYPE) ||
elf_writer_add_symbol(ew, "_ebss", section_name, rmod.bss_end, 0,
STB_GLOBAL, STT_NOTYPE)) {
ERROR("Unable to add bss symbols to ELF\n");
elf_writer_destroy(ew);
return -1;
}
ssize_t relocs_sz = rmod.relocations_end_offset;
relocs_sz -= rmod.relocations_begin_offset;
buffer_splice(&reader, buff, rmod.relocations_begin_offset, relocs_sz);
while (relocs_sz > 0) {
Elf64_Addr addr;
if (bit64) {
relocs_sz -= sizeof(Elf64_Addr);
addr = xdr->get64(&reader);
} else {
relocs_sz -= sizeof(Elf32_Addr);
addr = xdr->get32(&reader);
}
/* Skip any relocations that are below the link address. */
if (addr < rmod.module_link_start_address)
continue;
if (elf_writer_add_rel(ew, section_name, addr)) {
ERROR("Relocation addition failure.\n");
elf_writer_destroy(ew);
return -1;
}
}
if (elf_writer_serialize(ew, &elf_out)) {
ERROR("ELF writer serialize failure.\n");
elf_writer_destroy(ew);
return -1;
}
elf_writer_destroy(ew);
/* Flip buffer with the created ELF one. */
buffer_delete(buff);
*buff = elf_out;
return 0;
}