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Commit 8ab8a96c authored by Serge Bazanski's avatar Serge Bazanski
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epicardium/l0der: move to epic_file API

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epicardium/l0der/l0der.c
+ 75
− 98
View file @ 8ab8a96c
......@@ -3,7 +3,6 @@
#include <alloca.h>
#include <stdio.h>
#include <string.h>
#include <ff.h>
#include "epicardium.h"
#include "l0der/elf.h"
......@@ -56,46 +55,41 @@ struct _pie_load_info {
/*
* Read an ELF header, check E_IDENT.
*/
static int _read_elf_header(FIL *fp, Elf32_Ehdr *hdr)
static int _read_elf_header(int fd, Elf32_Ehdr *hdr)
{
f_lseek(fp, 0);
int res;
unsigned int read;
FRESULT fres = f_read(fp, hdr, sizeof(Elf32_Ehdr), &read);
if (fres != FR_OK) {
LOG_ERR("l0der", "_read_elf_header: f_read failed: %d", fres);
return -1;
}
epic_file_seek(fd, 0, SEEK_SET);
if (read != sizeof(Elf32_Ehdr)) {
LOG_ERR("l0der", "_read_elf_header: file truncated");
return -1;
if ((res = epic_file_read(fd, hdr, sizeof(Elf32_Ehdr))) != sizeof(Elf32_Ehdr)) {
LOG_ERR("l0der", "_read_elf_header: read failed: %d", res);
return res;
}
if (hdr->e_ident[0] != ELFMAG0 || hdr->e_ident[1] != ELFMAG1 ||
hdr->e_ident[2] != ELFMAG2 || hdr->e_ident[3] != ELFMAG3) {
LOG_ERR("l0der", "_read_elf_header: not an ELF file");
return -1;
return -ENOEXEC;
}
if (hdr->e_ident[4] != ELFCLASS32) {
LOG_ERR("l0der", "_read_elf_header: not a 32-bit ELF");
return -1;
return -ENOEXEC;
}
if (hdr->e_ident[5] != ELFDATA2LSB) {
LOG_ERR("l0der", "_read_elf_header: not a little-endian ELF");
return -1;
return -ENOEXEC;
}
if (hdr->e_ident[6] != EV_CURRENT) {
LOG_ERR("l0der", "_read_elf_header: not a v1 ELF");
return -1;
return -ENOEXEC;
}
if (hdr->e_ehsize < sizeof(Elf32_Ehdr)) {
LOG_ERR("l0der", "_raed_elf_header: header too small");
return -1;
return -ENOEXEC;
}
return 0;
......@@ -104,7 +98,7 @@ static int _read_elf_header(FIL *fp, Elf32_Ehdr *hdr)
/*
* Read bytes from file at a given offset.
*
* :param FIL* fp: file pointer to read from
* :param int fd: file pointer to read from
* :param uint32_t address: address from which to read
* :param void *data: buffer into which to read
* :param size_t count: amount of bytes to read
......@@ -112,31 +106,21 @@ static int _read_elf_header(FIL *fp, Elf32_Ehdr *hdr)
*
* - ``-EIO``: Could not read from FAT - address out of bounds of not enough bytes available.
*/
static int _seek_and_read(FIL *fp, uint32_t address, void *data, size_t count)
static int _seek_and_read(int fd, uint32_t address, void *data, size_t count)
{
FRESULT fres;
int res;
if ((fres = f_lseek(fp, address)) != FR_OK) {
if ((res = epic_file_seek(fd, address, SEEK_SET)) != 0) {
LOG_ERR("l0der",
"_seek_and_read: could not seek to 0x%lx: %d",
address,
fres);
return -EIO;
res);
return res;
}
unsigned int read;
if ((fres = f_read(fp, data, count, &read)) != FR_OK || read < count) {
if (fres == FR_OK) {
LOG_ERR("l0der",
"_seek_and_read: could not read: wanted %d bytes, got %d",
count,
read);
} else {
LOG_ERR("l0der",
"_seek_and_read: could not read: %d",
fres);
}
return -EIO;
if ((res = epic_file_read(fd, data, count)) != count) {
LOG_ERR("l0der","_seek_and_read: could not read: %d", res);
return res;
}
return 0;
......@@ -145,17 +129,17 @@ static int _seek_and_read(FIL *fp, uint32_t address, void *data, size_t count)
/*
* Read an ELF program header header.
*/
static int _read_program_header(FIL *fp, uint32_t phdr_addr, Elf32_Phdr *phdr)
static int _read_program_header(int fd, uint32_t phdr_addr, Elf32_Phdr *phdr)
{
return _seek_and_read(fp, phdr_addr, phdr, sizeof(Elf32_Phdr));
return _seek_and_read(fd, phdr_addr, phdr, sizeof(Elf32_Phdr));
}
/*
* Read an ELF section header header.
*/
static int _read_section_header(FIL *fp, uint32_t shdr_addr, Elf32_Shdr *shdr)
static int _read_section_header(int fd, uint32_t shdr_addr, Elf32_Shdr *shdr)
{
return _seek_and_read(fp, shdr_addr, shdr, sizeof(Elf32_Shdr));
return _seek_and_read(fd, shdr_addr, shdr, sizeof(Elf32_Shdr));
}
/*
......@@ -164,10 +148,8 @@ static int _read_section_header(FIL *fp, uint32_t shdr_addr, Elf32_Shdr *shdr)
* This function ensures basic memory sanity of a program header / segment.
* It ensures that it points to a file region that is contained within the file fully.
*/
static int _check_program_header(FIL *fp, Elf32_Phdr *phdr)
static int _check_program_header(int fd, int size, Elf32_Phdr *phdr)
{
size_t size = f_size(fp);
// Check file size/offset.
uint32_t file_start = phdr->p_offset;
uint32_t file_limit = phdr->p_offset + phdr->p_filesz;
......@@ -208,10 +190,8 @@ static int _check_program_header(FIL *fp, Elf32_Phdr *phdr)
* This function ensures basic memory sanity of a section header.
* It ensures that it points to a file region that is contained within the file fully.
*/
static int _check_section_header(FIL *fp, Elf32_Shdr *shdr)
static int _check_section_header(int fd, int size, Elf32_Shdr *shdr)
{
size_t size = f_size(fp);
// Check file size/offset.
uint32_t file_start = shdr->sh_offset;
uint32_t file_limit = shdr->sh_offset + shdr->sh_size;
......@@ -236,15 +216,15 @@ static const char *_interpreter = "card10-l0dable";
/*
* Check that the given INTERP program header contains the correct interpreter string.
*/
static int _check_interp(FIL *fp, Elf32_Phdr *phdr)
static int _check_interp(int fd, Elf32_Phdr *phdr)
{
int res;
uint32_t buffer_size = strlen(_interpreter) + 1;
char *interp = alloca(buffer_size);
memset(interp, 0, buffer_size);
if ((res = _seek_and_read(fp, phdr->p_offset, interp, buffer_size)) !=
FR_OK) {
if ((res = _seek_and_read(fd, phdr->p_offset, interp, buffer_size)) !=
0) {
return res;
}
......@@ -325,7 +305,7 @@ static int _get_load_addr(struct _pie_load_info *li)
*
* Segment must be a LOAD segment.
*/
static int _load_segment(FIL *fp, struct _pie_load_info *li, Elf32_Phdr *phdr)
static int _load_segment(int fd, struct _pie_load_info *li, Elf32_Phdr *phdr)
{
uint32_t segment_start = li->load_address + phdr->p_vaddr;
uint32_t segment_limit = segment_start + phdr->p_memsz;
......@@ -340,7 +320,7 @@ static int _load_segment(FIL *fp, struct _pie_load_info *li, Elf32_Phdr *phdr)
memset((void *)segment_start, 0, phdr->p_memsz);
return _seek_and_read(
fp, phdr->p_offset, (void *)segment_start, phdr->p_filesz
fd, phdr->p_offset, (void *)segment_start, phdr->p_filesz
);
}
......@@ -348,17 +328,16 @@ static int _load_segment(FIL *fp, struct _pie_load_info *li, Elf32_Phdr *phdr)
* Parse dynamic symbol sections.
*/
static int
_parse_dynamic_symbols(FIL *fp, struct _pie_load_info *li, Elf32_Ehdr *hdr)
_parse_dynamic_symbols(int fd, int size, struct _pie_load_info *li, Elf32_Ehdr *hdr)
{
int res;
FRESULT fres;
Elf32_Shdr shdr;
Elf32_Sym sym;
// Go through all dynamic symbol sections.
for (int i = 0; i < hdr->e_shnum; i++) {
uint32_t shdr_addr = hdr->e_shoff + (i * hdr->e_shentsize);
if ((res = _read_section_header(fp, shdr_addr, &shdr)) != 0) {
if ((res = _read_section_header(fd, shdr_addr, &shdr)) != 0) {
return res;
}
......@@ -366,7 +345,7 @@ _parse_dynamic_symbols(FIL *fp, struct _pie_load_info *li, Elf32_Ehdr *hdr)
continue;
}
if ((res = _check_section_header(fp, &shdr)) != 0) {
if ((res = _check_section_header(fd, size, &shdr)) != 0) {
return res;
}
......@@ -379,23 +358,21 @@ _parse_dynamic_symbols(FIL *fp, struct _pie_load_info *li, Elf32_Ehdr *hdr)
uint32_t sym_count = shdr.sh_size / sizeof(Elf32_Sym);
// Read symbols one by one.
if ((fres = f_lseek(fp, shdr.sh_offset)) != FR_OK) {
if ((res = epic_file_seek(fd, shdr.sh_offset, SEEK_SET)) != 0) {
LOG_ERR("l0der",
"_parse_dynamic_symbols: seek to first relocation (at 0x%lx) failed",
shdr.sh_offset);
return -EIO;
return res;
}
for (int j = 0; j < sym_count; j++) {
unsigned int read;
if ((fres = f_read(
fp, &sym, sizeof(Elf32_Sym), &read)) !=
FR_OK ||
read != sizeof(Elf32_Sym)) {
if ((res = epic_file_read(
fd, &sym, sizeof(Elf32_Sym))) !=
sizeof(Elf32_Sym)) {
LOG_ERR("l0der",
"__parse_dynamic_symbols: symbol read failed: %d",
fres);
return -EIO;
res);
return res;
}
uint32_t bind = ELF32_ST_BIND(sym.st_info);
......@@ -424,17 +401,16 @@ _parse_dynamic_symbols(FIL *fp, struct _pie_load_info *li, Elf32_Ehdr *hdr)
* the only one used when making 'standard' PIE binaries on RAM. However, other
* kinds might have to be implemented in the future.
*/
static int _run_relocations(FIL *fp, struct _pie_load_info *li, Elf32_Ehdr *hdr)
static int _run_relocations(int fd, int size, struct _pie_load_info *li, Elf32_Ehdr *hdr)
{
int res;
FRESULT fres;
Elf32_Shdr shdr;
Elf32_Rel rel;
// Go through all relocation sections.
for (int i = 0; i < hdr->e_shnum; i++) {
uint32_t shdr_addr = hdr->e_shoff + (i * hdr->e_shentsize);
if ((res = _read_section_header(fp, shdr_addr, &shdr)) != 0) {
if ((res = _read_section_header(fd, shdr_addr, &shdr)) != 0) {
return res;
}
......@@ -449,7 +425,7 @@ static int _run_relocations(FIL *fp, struct _pie_load_info *li, Elf32_Ehdr *hdr)
continue;
}
if ((res = _check_section_header(fp, &shdr)) != 0) {
if ((res = _check_section_header(fd, size, &shdr)) != 0) {
return res;
}
......@@ -457,28 +433,26 @@ static int _run_relocations(FIL *fp, struct _pie_load_info *li, Elf32_Ehdr *hdr)
LOG_ERR("l0der",
"_run_relocations: SHT_REL section with invalid size: %ld",
shdr.sh_size);
return -EIO;
return -ENOEXEC;
}
uint32_t reloc_count = shdr.sh_size / sizeof(Elf32_Rel);
// Read relocations one by one.
if ((fres = f_lseek(fp, shdr.sh_offset)) != FR_OK) {
if ((res = epic_file_seek(fd, shdr.sh_offset, SEEK_SET)) != 0) {
LOG_ERR("l0der",
"_run_relocations: seek to first relocation (at 0x%lx) failed",
shdr.sh_offset);
return -EIO;
return res;
}
for (int j = 0; j < reloc_count; j++) {
unsigned int read;
if ((fres = f_read(
fp, &rel, sizeof(Elf32_Rel), &read)) !=
FR_OK ||
read != sizeof(Elf32_Rel)) {
if ((res = epic_file_read(
fd, &rel, sizeof(Elf32_Rel))) !=
sizeof(Elf32_Rel)) {
LOG_ERR("l0der",
"_run_relocations: relocation read failed: %d",
fres);
return -EIO;
res);
return res;
}
uint32_t sym = ELF32_R_SYM(rel.r_info);
......@@ -536,7 +510,7 @@ static int _run_relocations(FIL *fp, struct _pie_load_info *li, Elf32_Ehdr *hdr)
/*
* Load a l0dable PIE binary.
*/
static int _load_pie(FIL *fp, Elf32_Ehdr *hdr, struct l0dable_info *info)
static int _load_pie(int fd, int size, Elf32_Ehdr *hdr, struct l0dable_info *info)
{
int res;
struct _pie_load_info li = { 0 };
......@@ -553,16 +527,16 @@ static int _load_pie(FIL *fp, Elf32_Ehdr *hdr, struct l0dable_info *info)
for (int i = 0; i < hdr->e_phnum; i++) {
uint32_t phdr_addr = hdr->e_phoff + (i * hdr->e_phentsize);
if ((res = _read_program_header(fp, phdr_addr, &phdr)) != 0) {
if ((res = _read_program_header(fd, phdr_addr, &phdr)) != 0) {
return res;
}
if ((res = _check_program_header(fp, &phdr)) != 0) {
if ((res = _check_program_header(fd, size, &phdr)) != 0) {
return res;
}
if (phdr.p_type == PT_INTERP) {
status_interp = _check_interp(fp, &phdr);
status_interp = _check_interp(fd, &phdr);
continue;
}
......@@ -620,7 +594,7 @@ static int _load_pie(FIL *fp, Elf32_Ehdr *hdr, struct l0dable_info *info)
for (int i = 0; i < hdr->e_phnum; i++) {
uint32_t phdr_addr = hdr->e_phoff + (i * hdr->e_phentsize);
if ((res = _read_program_header(fp, phdr_addr, &phdr)) != 0) {
if ((res = _read_program_header(fd, phdr_addr, &phdr)) != 0) {
return res;
}
......@@ -628,18 +602,18 @@ static int _load_pie(FIL *fp, Elf32_Ehdr *hdr, struct l0dable_info *info)
continue;
}
if ((res = _load_segment(fp, &li, &phdr)) != 0) {
if ((res = _load_segment(fd, &li, &phdr)) != 0) {
return res;
}
}
// Load dynamic symbols.
if ((res = _parse_dynamic_symbols(fp, &li, hdr)) != 0) {
if ((res = _parse_dynamic_symbols(fd, size, &li, hdr)) != 0) {
return res;
}
// Run relocations.
if ((res = _run_relocations(fp, &li, hdr)) != 0) {
if ((res = _run_relocations(fd, size, &li, hdr)) != 0) {
return res;
}
......@@ -656,26 +630,29 @@ static int _load_pie(FIL *fp, Elf32_Ehdr *hdr, struct l0dable_info *info)
int l0der_load_path(const char *path, struct l0dable_info *info)
{
FIL fh;
FRESULT fres = f_open(&fh, path, FA_OPEN_EXISTING | FA_READ);
if (fres != FR_OK) {
int fd, res;
if ((fd = epic_file_open(path, "rb")) < 0) {
LOG_ERR("l0der",
"l0der_load_path: could not open ELF file %s: %d",
path,
fres);
return -ENOENT;
fd);
return fd;
}
if ((res = epic_file_seek(fd, 0, SEEK_END)) != 0) {
return res;
}
int size = f_size(&fh);
int size = epic_file_tell(fd);
int res = 0;
if ((res = epic_file_seek(fd, 0, SEEK_SET)) != 0) {
return res;
}
// Load ELF header and ensure it's somewhat sane.
Elf32_Ehdr hdr;
if (_read_elf_header(&fh, &hdr) != 0) {
res = -EINVAL;
if ((res = _read_elf_header(fd, &hdr)) != 0) {
goto done;
}
......@@ -728,7 +705,7 @@ int l0der_load_path(const char *path, struct l0dable_info *info)
if (hdr.e_type == ET_DYN && hdr.e_machine == EM_ARM &&
hdr.e_version == EV_CURRENT) {
LOG_INFO("l0der", "Loading PIE l0dable %s ...", path);
res = _load_pie(&fh, &hdr, info);
res = _load_pie(fd, size, &hdr, info);
goto done;
} else {
LOG_ERR("l0der",
......@@ -739,6 +716,6 @@ int l0der_load_path(const char *path, struct l0dable_info *info)
}
done:
f_close(&fh);
epic_file_close(fd);
return res;
}
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