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flipperzero-firmware/lib/flipper_application/elf/elf_file.c
hedger 890c9e87ce
[FL-3690] Libraries cleanup; u2f crypto rework to use mbedtls (#3234) 
* examples: plugins: utilize fal_embedded
* libs: removed fnv1a_hash
* furi: added FURI_PACKED; apps, libs: changed to use FURI_PACKED
* lib: mbedtls: using custom config
* lib: toolbox: removed md5, switched to mbedtls
* targets: f18: link fix
* lib: added mbedtls_cfg.h
* apps: nfc: explicit dependency on libmbedtls
* u2f: reworking to mbedtls
* u2f: replaced sha256 & hmac with mbedtls
* u2f: functional rework using mbedtls
* libs: dropped micro-ecc
* u2f: dropped old implementation
* toolbox: removed sha256 impl
* mcheck() for mbedtls
* libs: removed libmisc; split into smaller libs
* apps: debug: fixed display_test
* apps: include cleanups
* fbt: fixed VERSIONCOMSTR
* furi: added FURI_CHECK_RETURN
* lib: removed qrcode
* cleanup
* fbt: lint_py+format_py: fixed excessive command length
* api: Removed bzero from f7
* api: Removed bzero from f18
* Bump API Symbols

Co-authored-by: Aleksandr Kutuzov <alleteam@gmail.com>
2023-12-01 18:16:48 +09:00

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#include "elf_file.h"
#include "elf_file_i.h"
#include <storage/storage.h>
#include <elf.h>
#include "elf_api_interface.h"
#include "../api_hashtable/api_hashtable.h"
#define TAG "Elf"
#define ELF_NAME_BUFFER_LEN 32
#define SECTION_OFFSET(e, n) ((e)->section_table + (n) * sizeof(Elf32_Shdr))
#define IS_FLAGS_SET(v, m) (((v) & (m)) == (m))
#define RESOLVER_THREAD_YIELD_STEP 30
#define FAST_RELOCATION_VERSION 1
// #define ELF_DEBUG_LOG 1
#ifndef ELF_DEBUG_LOG
#undef FURI_LOG_D
#define FURI_LOG_D(...)
#endif
#define ELF_INVALID_ADDRESS 0xFFFFFFFF
#define TRAMPOLINE_CODE_SIZE 6
/**
ldr r12, [pc, #2]
bx r12
*/
const uint8_t trampoline_code_little_endian[TRAMPOLINE_CODE_SIZE] =
{0xdf, 0xf8, 0x02, 0xc0, 0x60, 0x47};
typedef struct {
uint8_t code[TRAMPOLINE_CODE_SIZE];
uint32_t addr;
} FURI_PACKED JMPTrampoline;
/**************************************************************************************************/
/********************************************* Caches *********************************************/
/**************************************************************************************************/
static bool address_cache_get(AddressCache_t cache, int symEntry, Elf32_Addr* symAddr) {
Elf32_Addr* addr = AddressCache_get(cache, symEntry);
if(addr) {
*symAddr = *addr;
return true;
} else {
return false;
}
}
static void address_cache_put(AddressCache_t cache, int symEntry, Elf32_Addr symAddr) {
AddressCache_set_at(cache, symEntry, symAddr);
}
/**************************************************************************************************/
/********************************************** ELF ***********************************************/
/**************************************************************************************************/
static void elf_file_maybe_release_fd(ELFFile* elf) {
if(elf->fd) {
storage_file_free(elf->fd);
elf->fd = NULL;
}
}
static ELFSection* elf_file_get_section(ELFFile* elf, const char* name) {
return ELFSectionDict_get(elf->sections, name);
}
static ELFSection* elf_file_get_or_put_section(ELFFile* elf, const char* name) {
ELFSection* section_p = elf_file_get_section(elf, name);
if(!section_p) {
ELFSectionDict_set_at(
elf->sections,
strdup(name),
(ELFSection){
.data = NULL,
.sec_idx = 0,
.size = 0,
.rel_count = 0,
.rel_offset = 0,
.fast_rel = NULL,
});
section_p = elf_file_get_section(elf, name);
}
return section_p;
}
static bool elf_read_string_from_offset(ELFFile* elf, off_t offset, FuriString* name) {
bool result = false;
off_t old = storage_file_tell(elf->fd);
do {
if(!storage_file_seek(elf->fd, offset, true)) break;
char buffer[ELF_NAME_BUFFER_LEN + 1];
buffer[ELF_NAME_BUFFER_LEN] = 0;
while(true) {
size_t read = storage_file_read(elf->fd, buffer, ELF_NAME_BUFFER_LEN);
furi_string_cat(name, buffer);
if(strlen(buffer) < ELF_NAME_BUFFER_LEN) {
result = true;
break;
}
if(storage_file_get_error(elf->fd) != FSE_OK || read == 0) break;
}
} while(false);
storage_file_seek(elf->fd, old, true);
return result;
}
static bool elf_read_section_name(ELFFile* elf, off_t offset, FuriString* name) {
return elf_read_string_from_offset(elf, elf->section_table_strings + offset, name);
}
static bool elf_read_symbol_name(ELFFile* elf, off_t offset, FuriString* name) {
return elf_read_string_from_offset(elf, elf->symbol_table_strings + offset, name);
}
static bool elf_read_section_header(ELFFile* elf, size_t section_idx, Elf32_Shdr* section_header) {
off_t offset = SECTION_OFFSET(elf, section_idx);
return storage_file_seek(elf->fd, offset, true) &&
storage_file_read(elf->fd, section_header, sizeof(Elf32_Shdr)) == sizeof(Elf32_Shdr);
}
static bool elf_read_section(
ELFFile* elf,
size_t section_idx,
Elf32_Shdr* section_header,
FuriString* name) {
if(!elf_read_section_header(elf, section_idx, section_header)) {
return false;
}
if(section_header->sh_name && !elf_read_section_name(elf, section_header->sh_name, name)) {
return false;
}
return true;
}
static bool elf_read_symbol(ELFFile* elf, int n, Elf32_Sym* sym, FuriString* name) {
bool success = false;
off_t old = storage_file_tell(elf->fd);
off_t pos = elf->symbol_table + n * sizeof(Elf32_Sym);
if(storage_file_seek(elf->fd, pos, true) &&
storage_file_read(elf->fd, sym, sizeof(Elf32_Sym)) == sizeof(Elf32_Sym)) {
if(sym->st_name)
success = elf_read_symbol_name(elf, sym->st_name, name);
else {
Elf32_Shdr shdr;
success = elf_read_section(elf, sym->st_shndx, &shdr, name);
}
}
storage_file_seek(elf->fd, old, true);
return success;
}
static ELFSection* elf_section_of(ELFFile* elf, int index) {
ELFSectionDict_it_t it;
for(ELFSectionDict_it(it, elf->sections); !ELFSectionDict_end_p(it); ELFSectionDict_next(it)) {
ELFSectionDict_itref_t* itref = ELFSectionDict_ref(it);
if(itref->value.sec_idx == index) {
return &itref->value;
}
}
return NULL;
}
static Elf32_Addr elf_address_of(ELFFile* elf, Elf32_Sym* sym, const char* sName) {
if(sym->st_shndx == SHN_UNDEF) {
Elf32_Addr addr = 0;
uint32_t hash = elf_symbolname_hash(sName);
if(elf->api_interface->resolver_callback(elf->api_interface, hash, &addr)) {
return addr;
}
} else {
ELFSection* symSec = elf_section_of(elf, sym->st_shndx);
if(symSec) {
return ((Elf32_Addr)symSec->data) + sym->st_value;
}
}
FURI_LOG_D(TAG, " Can not find address for symbol %s", sName);
return ELF_INVALID_ADDRESS;
}
__attribute__((unused)) static const char* elf_reloc_type_to_str(int symt) {
#define STRCASE(name) \
case name: \
return #name;
switch(symt) {
STRCASE(R_ARM_NONE)
STRCASE(R_ARM_TARGET1)
STRCASE(R_ARM_ABS32)
STRCASE(R_ARM_THM_PC22)
STRCASE(R_ARM_THM_JUMP24)
default:
return "R_<unknow>";
}
#undef STRCASE
}
static JMPTrampoline* elf_create_trampoline(Elf32_Addr addr) {
JMPTrampoline* trampoline = malloc(sizeof(JMPTrampoline));
memcpy(trampoline->code, trampoline_code_little_endian, TRAMPOLINE_CODE_SIZE);
trampoline->addr = addr;
return trampoline;
}
static void elf_relocate_jmp_call(ELFFile* elf, Elf32_Addr relAddr, int type, Elf32_Addr symAddr) {
int offset, hi, lo, s, j1, j2, i1, i2, imm10, imm11;
int to_thumb, is_call, blx_bit = 1 << 12;
/* Get initial offset */
hi = ((uint16_t*)relAddr)[0];
lo = ((uint16_t*)relAddr)[1];
s = (hi >> 10) & 1;
j1 = (lo >> 13) & 1;
j2 = (lo >> 11) & 1;
i1 = (j1 ^ s) ^ 1;
i2 = (j2 ^ s) ^ 1;
imm10 = hi & 0x3ff;
imm11 = lo & 0x7ff;
offset = (s << 24) | (i1 << 23) | (i2 << 22) | (imm10 << 12) | (imm11 << 1);
if(offset & 0x01000000) offset -= 0x02000000;
to_thumb = symAddr & 1;
is_call = (type == R_ARM_THM_PC22);
/* Store offset */
int offset_copy = offset;
/* Compute final offset */
offset += symAddr - relAddr;
if(!to_thumb && is_call) {
blx_bit = 0; /* bl -> blx */
offset = (offset + 3) & -4; /* Compute offset from aligned PC */
}
/* Check that relocation is possible
* offset must not be out of range
* if target is to be entered in arm mode:
- bit 1 must not set
- instruction must be a call (bl) or a jump to PLT */
if(!to_thumb || offset >= 0x1000000 || offset < -0x1000000) {
if(to_thumb || (symAddr & 2) || (!is_call)) {
FURI_LOG_D(
TAG,
"can't relocate value at %lx, %s, doing trampoline",
relAddr,
elf_reloc_type_to_str(type));
Elf32_Addr addr;
if(!address_cache_get(elf->trampoline_cache, symAddr, &addr)) {
addr = (Elf32_Addr)elf_create_trampoline(symAddr);
address_cache_put(elf->trampoline_cache, symAddr, addr);
}
offset = offset_copy;
offset += (int)addr - relAddr;
if(!to_thumb && is_call) {
blx_bit = 0; /* bl -> blx */
offset = (offset + 3) & -4; /* Compute offset from aligned PC */
}
}
}
/* Compute and store final offset */
s = (offset >> 24) & 1;
i1 = (offset >> 23) & 1;
i2 = (offset >> 22) & 1;
j1 = s ^ (i1 ^ 1);
j2 = s ^ (i2 ^ 1);
imm10 = (offset >> 12) & 0x3ff;
imm11 = (offset >> 1) & 0x7ff;
(*(uint16_t*)relAddr) = (uint16_t)((hi & 0xf800) | (s << 10) | imm10);
(*(uint16_t*)(relAddr + 2)) =
(uint16_t)((lo & 0xc000) | (j1 << 13) | blx_bit | (j2 << 11) | imm11);
}
static void elf_relocate_mov(Elf32_Addr relAddr, int type, Elf32_Addr symAddr) {
uint16_t upper_insn = ((uint16_t*)relAddr)[0];
uint16_t lower_insn = ((uint16_t*)relAddr)[1];
/* MOV*<C> <Rd>,#<imm16>
*
* i = upper[10]
* imm4 = upper[3:0]
* imm3 = lower[14:12]
* imm8 = lower[7:0]
*
* imm16 = imm4:i:imm3:imm8
*/
uint32_t i = (upper_insn >> 10) & 1; /* upper[10] */
uint32_t imm4 = upper_insn & 0x000F; /* upper[3:0] */
uint32_t imm3 = (lower_insn >> 12) & 0x7; /* lower[14:12] */
uint32_t imm8 = lower_insn & 0x00FF; /* lower[7:0] */
int32_t addend = (imm4 << 12) | (i << 11) | (imm3 << 8) | imm8; /* imm16 */
uint32_t addr = (symAddr + addend);
if(type == R_ARM_THM_MOVT_ABS) {
addr >>= 16; /* upper 16 bits */
} else {
addr &= 0x0000FFFF; /* lower 16 bits */
}
/* Re-encode */
((uint16_t*)relAddr)[0] = (upper_insn & 0xFBF0) | (((addr >> 11) & 1) << 10) /* i */
| ((addr >> 12) & 0x000F); /* imm4 */
((uint16_t*)relAddr)[1] = (lower_insn & 0x8F00) | (((addr >> 8) & 0x7) << 12) /* imm3 */
| (addr & 0x00FF); /* imm8 */
}
static bool elf_relocate_symbol(ELFFile* elf, Elf32_Addr relAddr, int type, Elf32_Addr symAddr) {
switch(type) {
case R_ARM_TARGET1:
case R_ARM_ABS32:
*((uint32_t*)relAddr) += symAddr;
FURI_LOG_D(TAG, " R_ARM_ABS32 relocated is 0x%08X", (unsigned int)*((uint32_t*)relAddr));
break;
case R_ARM_THM_PC22:
case R_ARM_CALL:
case R_ARM_THM_JUMP24:
elf_relocate_jmp_call(elf, relAddr, type, symAddr);
FURI_LOG_D(
TAG, " R_ARM_THM_CALL/JMP relocated is 0x%08X", (unsigned int)*((uint32_t*)relAddr));
break;
case R_ARM_THM_MOVW_ABS_NC:
case R_ARM_THM_MOVT_ABS:
elf_relocate_mov(relAddr, type, symAddr);
FURI_LOG_D(
TAG,
" R_ARM_THM_MOVW_ABS_NC/MOVT_ABS relocated is 0x%08X",
(unsigned int)*((uint32_t*)relAddr));
break;
default:
FURI_LOG_E(TAG, " Undefined relocation %d", type);
return false;
}
return true;
}
static bool elf_relocate(ELFFile* elf, ELFSection* s) {
if(s->data) {
Elf32_Rel rel;
size_t relEntries = s->rel_count;
size_t relCount;
(void)storage_file_seek(elf->fd, s->rel_offset, true);
FURI_LOG_D(TAG, " Offset Info Type Name");
int relocate_result = true;
FuriString* symbol_name;
symbol_name = furi_string_alloc();
for(relCount = 0; relCount < relEntries; relCount++) {
if(relCount % RESOLVER_THREAD_YIELD_STEP == 0) {
FURI_LOG_D(TAG, " reloc YIELD");
furi_delay_tick(1);
}
if(storage_file_read(elf->fd, &rel, sizeof(Elf32_Rel)) != sizeof(Elf32_Rel)) {
FURI_LOG_E(TAG, " reloc read fail");
furi_string_free(symbol_name);
return false;
}
Elf32_Addr symAddr;
int symEntry = ELF32_R_SYM(rel.r_info);
int relType = ELF32_R_TYPE(rel.r_info);
Elf32_Addr relAddr = ((Elf32_Addr)s->data) + rel.r_offset;
if(!address_cache_get(elf->relocation_cache, symEntry, &symAddr)) {
Elf32_Sym sym;
furi_string_reset(symbol_name);
if(!elf_read_symbol(elf, symEntry, &sym, symbol_name)) {
FURI_LOG_E(TAG, " symbol read fail");
furi_string_free(symbol_name);
return false;
}
FURI_LOG_D(
TAG,
" %08X %08X %-16s %s",
(unsigned int)rel.r_offset,
(unsigned int)rel.r_info,
elf_reloc_type_to_str(relType),
furi_string_get_cstr(symbol_name));
symAddr = elf_address_of(elf, &sym, furi_string_get_cstr(symbol_name));
address_cache_put(elf->relocation_cache, symEntry, symAddr);
}
if(symAddr != ELF_INVALID_ADDRESS) {
FURI_LOG_D(
TAG,
" symAddr=%08X relAddr=%08X",
(unsigned int)symAddr,
(unsigned int)relAddr);
if(!elf_relocate_symbol(elf, relAddr, relType, symAddr)) {
relocate_result = false;
}
} else {
FURI_LOG_E(TAG, " No symbol address of %s", furi_string_get_cstr(symbol_name));
relocate_result = false;
}
}
furi_string_free(symbol_name);
return relocate_result;
} else {
FURI_LOG_D(TAG, "Section not loaded");
}
return false;
}
/**************************************************************************************************/
/************************************ Internal FAP interfaces *************************************/
/**************************************************************************************************/
typedef enum {
SectionTypeERROR = 0,
SectionTypeUnused = 1 << 0,
SectionTypeData = 1 << 1,
SectionTypeRelData = 1 << 2,
SectionTypeSymTab = 1 << 3,
SectionTypeStrTab = 1 << 4,
SectionTypeDebugLink = 1 << 5,
SectionTypeFastRelData = 1 << 6,
SectionTypeValid = SectionTypeSymTab | SectionTypeStrTab,
} SectionType;
static bool elf_load_debug_link(ELFFile* elf, Elf32_Shdr* section_header) {
elf->debug_link_info.debug_link_size = section_header->sh_size;
elf->debug_link_info.debug_link = malloc(section_header->sh_size);
return storage_file_seek(elf->fd, section_header->sh_offset, true) &&
storage_file_read(elf->fd, elf->debug_link_info.debug_link, section_header->sh_size) ==
section_header->sh_size;
}
static bool str_prefix(const char* str, const char* prefix) {
return strncmp(prefix, str, strlen(prefix)) == 0;
}
static bool elf_load_section_data(ELFFile* elf, ELFSection* section, Elf32_Shdr* section_header) {
if(section_header->sh_size == 0) {
FURI_LOG_D(TAG, "No data for section");
return true;
}
section->data = aligned_malloc(section_header->sh_size, section_header->sh_addralign);
section->size = section_header->sh_size;
if(section_header->sh_type == SHT_NOBITS) {
// BSS section, no data to load
return true;
}
if((!storage_file_seek(elf->fd, section_header->sh_offset, true)) ||
(storage_file_read(elf->fd, section->data, section_header->sh_size) !=
section_header->sh_size)) {
FURI_LOG_E(TAG, " seek/read fail");
return false;
}
FURI_LOG_D(TAG, "0x%p", section->data);
return true;
}
static SectionType elf_preload_section(
ELFFile* elf,
size_t section_idx,
Elf32_Shdr* section_header,
FuriString* name_string) {
const char* name = furi_string_get_cstr(name_string);
#ifdef ELF_DEBUG_LOG
// log section name, type and flags
FuriString* flags_string = furi_string_alloc();
if(section_header->sh_flags & SHF_WRITE) furi_string_cat(flags_string, "W");
if(section_header->sh_flags & SHF_ALLOC) furi_string_cat(flags_string, "A");
if(section_header->sh_flags & SHF_EXECINSTR) furi_string_cat(flags_string, "X");
if(section_header->sh_flags & SHF_MERGE) furi_string_cat(flags_string, "M");
if(section_header->sh_flags & SHF_STRINGS) furi_string_cat(flags_string, "S");
if(section_header->sh_flags & SHF_INFO_LINK) furi_string_cat(flags_string, "I");
if(section_header->sh_flags & SHF_LINK_ORDER) furi_string_cat(flags_string, "L");
if(section_header->sh_flags & SHF_OS_NONCONFORMING) furi_string_cat(flags_string, "O");
if(section_header->sh_flags & SHF_GROUP) furi_string_cat(flags_string, "G");
if(section_header->sh_flags & SHF_TLS) furi_string_cat(flags_string, "T");
if(section_header->sh_flags & SHF_COMPRESSED) furi_string_cat(flags_string, "T");
if(section_header->sh_flags & SHF_MASKOS) furi_string_cat(flags_string, "o");
if(section_header->sh_flags & SHF_MASKPROC) furi_string_cat(flags_string, "p");
if(section_header->sh_flags & SHF_ORDERED) furi_string_cat(flags_string, "R");
if(section_header->sh_flags & SHF_EXCLUDE) furi_string_cat(flags_string, "E");
FURI_LOG_I(
TAG,
"Section %s: type: %ld, flags: %s",
name,
section_header->sh_type,
furi_string_get_cstr(flags_string));
furi_string_free(flags_string);
#endif
// ignore .ARM and .rel.ARM sections
// TODO FL-3525: how to do it not by name?
// .ARM: type 0x70000001, flags SHF_ALLOC | SHF_LINK_ORDER
// .rel.ARM: type 0x9, flags SHT_REL
if(str_prefix(name, ".ARM.") || str_prefix(name, ".rel.ARM.") ||
str_prefix(name, ".fast.rel.ARM.")) {
FURI_LOG_D(TAG, "Ignoring ARM section");
return SectionTypeUnused;
}
// Load allocable section
if(section_header->sh_flags & SHF_ALLOC) {
ELFSection* section_p = elf_file_get_or_put_section(elf, name);
section_p->sec_idx = section_idx;
if(section_header->sh_type == SHT_PREINIT_ARRAY) {
furi_assert(elf->preinit_array == NULL);
elf->preinit_array = section_p;
} else if(section_header->sh_type == SHT_INIT_ARRAY) {
furi_assert(elf->init_array == NULL);
elf->init_array = section_p;
} else if(section_header->sh_type == SHT_FINI_ARRAY) {
furi_assert(elf->fini_array == NULL);
elf->fini_array = section_p;
}
if(!elf_load_section_data(elf, section_p, section_header)) {
FURI_LOG_E(TAG, "Error loading section '%s'", name);
return SectionTypeERROR;
} else {
return SectionTypeData;
}
}
// Load link info section
if(section_header->sh_flags & SHF_INFO_LINK) {
if(str_prefix(name, ".rel")) {
name = name + strlen(".rel");
ELFSection* section_p = elf_file_get_or_put_section(elf, name);
section_p->rel_count = section_header->sh_size / sizeof(Elf32_Rel);
section_p->rel_offset = section_header->sh_offset;
return SectionTypeRelData;
} else {
FURI_LOG_E(TAG, "Unknown link info section '%s'", name);
return SectionTypeERROR;
}
}
// Load fast rel section
if(str_prefix(name, ".fast.rel")) {
name = name + strlen(".fast.rel");
ELFSection* section_p = elf_file_get_or_put_section(elf, name);
section_p->fast_rel = malloc(sizeof(ELFSection));
if(!elf_load_section_data(elf, section_p->fast_rel, section_header)) {
FURI_LOG_E(TAG, "Error loading section '%s'", name);
return SectionTypeERROR;
}
FURI_LOG_D(TAG, "Loaded fast rel section for '%s'", name);
return SectionTypeFastRelData;
}
// Load symbol table
if(strcmp(name, ".symtab") == 0) {
FURI_LOG_D(TAG, "Found .symtab section");
elf->symbol_table = section_header->sh_offset;
elf->symbol_count = section_header->sh_size / sizeof(Elf32_Sym);
return SectionTypeSymTab;
}
// Load string table
if(strcmp(name, ".strtab") == 0) {
FURI_LOG_D(TAG, "Found .strtab section");
elf->symbol_table_strings = section_header->sh_offset;
return SectionTypeStrTab;
}
// Load debug link section
if(strcmp(name, ".gnu_debuglink") == 0) {
FURI_LOG_D(TAG, "Found .gnu_debuglink section");
if(elf_load_debug_link(elf, section_header)) {
return SectionTypeDebugLink;
} else {
return SectionTypeERROR;
}
}
return SectionTypeUnused;
}
static Elf32_Addr elf_address_of_by_hash(ELFFile* elf, uint32_t hash) {
Elf32_Addr addr = 0;
if(elf->api_interface->resolver_callback(elf->api_interface, hash, &addr)) {
return addr;
}
return ELF_INVALID_ADDRESS;
}
static bool elf_file_find_string_by_hash(ELFFile* elf, uint32_t hash, FuriString* out) {
bool result = false;
FuriString* symbol_name = furi_string_alloc();
Elf32_Sym sym;
for(size_t i = 0; i < elf->symbol_count; i++) {
furi_string_reset(symbol_name);
if(elf_read_symbol(elf, i, &sym, symbol_name)) {
if(elf_symbolname_hash(furi_string_get_cstr(symbol_name)) == hash) {
furi_string_set(out, symbol_name);
result = true;
break;
}
}
}
furi_string_free(symbol_name);
return result;
}
static bool elf_relocate_fast(ELFFile* elf, ELFSection* s) {
UNUSED(elf);
const uint8_t* start = s->fast_rel->data;
const uint8_t version = *start;
bool no_errors = true;
if(version != FAST_RELOCATION_VERSION) {
FURI_LOG_E(TAG, "Unsupported fast relocation version %d", version);
return false;
}
start += 1;
const uint32_t records_count = *((uint32_t*)start);
start += 4;
FURI_LOG_D(TAG, "Fast relocation records count: %ld", records_count);
for(uint32_t i = 0; i < records_count; i++) {
bool is_section = (*start & (0x1 << 7)) ? true : false;
uint8_t type = *start & 0x7F;
start += 1;
uint32_t hash_or_section_index = *((uint32_t*)start);
start += 4;
uint32_t section_value = ELF_INVALID_ADDRESS;
if(is_section) {
section_value = *((uint32_t*)start);
start += 4;
}
const uint32_t offsets_count = *((uint32_t*)start);
start += 4;
FURI_LOG_D(
TAG,
"Fast relocation record %ld: is_section=%d, type=%d, hash_or_section_index=%lX, offsets_count=%ld",
i,
is_section,
type,
hash_or_section_index,
offsets_count);
Elf32_Addr address = 0;
if(is_section) {
ELFSection* symSec = elf_section_of(elf, hash_or_section_index);
if(symSec) {
address = ((Elf32_Addr)symSec->data) + section_value;
}
} else {
address = elf_address_of_by_hash(elf, hash_or_section_index);
}
if(address == ELF_INVALID_ADDRESS) {
FuriString* symbol_name = furi_string_alloc();
if(elf_file_find_string_by_hash(elf, hash_or_section_index, symbol_name)) {
FURI_LOG_E(
TAG,
"Failed to resolve address for symbol %s (hash %lX)",
furi_string_get_cstr(symbol_name),
hash_or_section_index);
} else {
FURI_LOG_E(
TAG,
"Failed to resolve address for hash %lX (string not found)",
hash_or_section_index);
}
furi_string_free(symbol_name);
no_errors = false;
start += 3 * offsets_count;
} else {
for(uint32_t j = 0; j < offsets_count; j++) {
uint32_t offset = *((uint32_t*)start) & 0x00FFFFFF;
start += 3;
Elf32_Addr relAddr = ((Elf32_Addr)s->data) + offset;
elf_relocate_symbol(elf, relAddr, type, address);
}
}
}
aligned_free(s->fast_rel->data);
free(s->fast_rel);
s->fast_rel = NULL;
return no_errors;
}
static bool elf_relocate_section(ELFFile* elf, ELFSection* section) {
if(section->fast_rel) {
FURI_LOG_D(TAG, "Fast relocating section");
return elf_relocate_fast(elf, section);
} else if(section->rel_count) {
FURI_LOG_D(TAG, "Relocating section");
return elf_relocate(elf, section);
} else {
FURI_LOG_D(TAG, "No relocation index"); /* Not an error */
}
return true;
}
static void elf_file_call_section_list(ELFSection* section, bool reverse_order) {
if(section && section->size) {
const uint32_t* start = section->data;
const uint32_t* end = section->data + section->size;
if(reverse_order) {
while(end > start) {
end--;
((void (*)(void))(*end))();
}
} else {
while(start < end) {
((void (*)(void))(*start))();
start++;
}
}
}
}
/**************************************************************************************************/
/********************************************* Public *********************************************/
/**************************************************************************************************/
ELFFile* elf_file_alloc(Storage* storage, const ElfApiInterface* api_interface) {
ELFFile* elf = malloc(sizeof(ELFFile));
elf->fd = storage_file_alloc(storage);
elf->api_interface = api_interface;
ELFSectionDict_init(elf->sections);
AddressCache_init(elf->trampoline_cache);
elf->init_array_called = false;
return elf;
}
void elf_file_free(ELFFile* elf) {
// furi_check(!elf->init_array_called);
if(elf->init_array_called) {
FURI_LOG_W(TAG, "Init array was called, but fini array wasn't");
elf_file_call_section_list(elf->fini_array, true);
}
// free sections data
{
ELFSectionDict_it_t it;
for(ELFSectionDict_it(it, elf->sections); !ELFSectionDict_end_p(it);
ELFSectionDict_next(it)) {
const ELFSectionDict_itref_t* itref = ELFSectionDict_cref(it);
if(itref->value.data) {
aligned_free(itref->value.data);
}
if(itref->value.fast_rel) {
aligned_free(itref->value.fast_rel->data);
free(itref->value.fast_rel);
}
free((void*)itref->key);
}
ELFSectionDict_clear(elf->sections);
}
// free trampoline data
{
AddressCache_it_t it;
for(AddressCache_it(it, elf->trampoline_cache); !AddressCache_end_p(it);
AddressCache_next(it)) {
const AddressCache_itref_t* itref = AddressCache_cref(it);
free((void*)itref->value);
}
AddressCache_clear(elf->trampoline_cache);
}
if(elf->debug_link_info.debug_link) {
free(elf->debug_link_info.debug_link);
}
elf_file_maybe_release_fd(elf);
free(elf);
}
bool elf_file_open(ELFFile* elf, const char* path) {
Elf32_Ehdr h;
Elf32_Shdr sH;
if(!storage_file_open(elf->fd, path, FSAM_READ, FSOM_OPEN_EXISTING) ||
!storage_file_seek(elf->fd, 0, true) ||
storage_file_read(elf->fd, &h, sizeof(h)) != sizeof(h) ||
!storage_file_seek(elf->fd, h.e_shoff + h.e_shstrndx * sizeof(sH), true) ||
storage_file_read(elf->fd, &sH, sizeof(Elf32_Shdr)) != sizeof(Elf32_Shdr)) {
return false;
}
elf->entry = h.e_entry;
elf->sections_count = h.e_shnum;
elf->section_table = h.e_shoff;
elf->section_table_strings = sH.sh_offset;
return true;
}
bool elf_file_load_section_table(ELFFile* elf) {
SectionType loaded_sections = SectionTypeERROR;
FuriString* name = furi_string_alloc();
FURI_LOG_D(TAG, "Scan ELF indexs...");
// TODO FL-3526: why we start from 1?
for(size_t section_idx = 1; section_idx < elf->sections_count; section_idx++) {
Elf32_Shdr section_header;
furi_string_reset(name);
if(!elf_read_section(elf, section_idx, &section_header, name)) {
loaded_sections = SectionTypeERROR;
break;
}
FURI_LOG_D(
TAG, "Preloading data for section #%d %s", section_idx, furi_string_get_cstr(name));
SectionType section_type = elf_preload_section(elf, section_idx, &section_header, name);
loaded_sections |= section_type;
if(section_type == SectionTypeERROR) {
loaded_sections = SectionTypeERROR;
break;
}
}
furi_string_free(name);
return IS_FLAGS_SET(loaded_sections, SectionTypeValid);
}
ElfProcessSectionResult elf_process_section(
ELFFile* elf,
const char* name,
ElfProcessSection* process_section,
void* context) {
ElfProcessSectionResult result = ElfProcessSectionResultNotFound;
FuriString* section_name = furi_string_alloc();
Elf32_Shdr section_header;
// find section
// TODO FL-3526: why we start from 1?
for(size_t section_idx = 1; section_idx < elf->sections_count; section_idx++) {
furi_string_reset(section_name);
if(!elf_read_section(elf, section_idx, &section_header, section_name)) {
break;
}
if(furi_string_cmp(section_name, name) == 0) {
result = ElfProcessSectionResultCannotProcess;
break;
}
}
if(result != ElfProcessSectionResultNotFound) { //-V547
if(process_section(elf->fd, section_header.sh_offset, section_header.sh_size, context)) {
result = ElfProcessSectionResultSuccess;
} else {
result = ElfProcessSectionResultCannotProcess; //-V1048
}
}
furi_string_free(section_name);
return result;
}
ELFFileLoadStatus elf_file_load_sections(ELFFile* elf) {
furi_check(elf->fd != NULL);
ELFFileLoadStatus status = ELFFileLoadStatusSuccess;
ELFSectionDict_it_t it;
AddressCache_init(elf->relocation_cache);
for(ELFSectionDict_it(it, elf->sections); !ELFSectionDict_end_p(it); ELFSectionDict_next(it)) {
ELFSectionDict_itref_t* itref = ELFSectionDict_ref(it);
FURI_LOG_D(TAG, "Relocating section '%s'", itref->key);
if(!elf_relocate_section(elf, &itref->value)) {
FURI_LOG_E(TAG, "Error relocating section '%s'", itref->key);
status = ELFFileLoadStatusMissingImports;
}
}
/* Fixing up entry point */
if(status == ELFFileLoadStatusSuccess) {
ELFSection* text_section = elf_file_get_section(elf, ".text");
if(text_section == NULL) {
FURI_LOG_E(TAG, "No .text section found");
status = ELFFileLoadStatusUnspecifiedError;
} else {
elf->entry += (uint32_t)text_section->data;
}
}
FURI_LOG_D(TAG, "Relocation cache size: %u", AddressCache_size(elf->relocation_cache));
FURI_LOG_D(TAG, "Trampoline cache size: %u", AddressCache_size(elf->trampoline_cache));
AddressCache_clear(elf->relocation_cache);
{
size_t total_size = 0;
for(ELFSectionDict_it(it, elf->sections); !ELFSectionDict_end_p(it);
ELFSectionDict_next(it)) {
ELFSectionDict_itref_t* itref = ELFSectionDict_ref(it);
total_size += itref->value.size;
}
FURI_LOG_I(TAG, "Total size of loaded sections: %zu", total_size);
}
elf_file_maybe_release_fd(elf);
return status;
}
void elf_file_call_init(ELFFile* elf) {
furi_check(!elf->init_array_called);
elf_file_call_section_list(elf->preinit_array, false);
elf_file_call_section_list(elf->init_array, false);
elf->init_array_called = true;
}
bool elf_file_is_init_complete(ELFFile* elf) {
return elf->init_array_called;
}
void* elf_file_get_entry_point(ELFFile* elf) {
furi_check(elf->init_array_called);
return (void*)elf->entry;
}
void elf_file_call_fini(ELFFile* elf) {
furi_check(elf->init_array_called);
elf_file_call_section_list(elf->fini_array, true);
elf->init_array_called = false;
}
const ElfApiInterface* elf_file_get_api_interface(ELFFile* elf_file) {
return elf_file->api_interface;
}
void elf_file_init_debug_info(ELFFile* elf, ELFDebugInfo* debug_info) {
// set entry
debug_info->entry = elf->entry;
// copy debug info
memcpy(&debug_info->debug_link_info, &elf->debug_link_info, sizeof(ELFDebugLinkInfo));
// init mmap
debug_info->mmap_entry_count = ELFSectionDict_size(elf->sections);
debug_info->mmap_entries = malloc(sizeof(ELFMemoryMapEntry) * debug_info->mmap_entry_count);
uint32_t mmap_entry_idx = 0;
ELFSectionDict_it_t it;
for(ELFSectionDict_it(it, elf->sections); !ELFSectionDict_end_p(it); ELFSectionDict_next(it)) {
const ELFSectionDict_itref_t* itref = ELFSectionDict_cref(it);
const void* data_ptr = itref->value.data;
if(data_ptr) {
ELFMemoryMapEntry* entry = &debug_info->mmap_entries[mmap_entry_idx];
entry->address = (uint32_t)data_ptr;
entry->name = itref->key;
mmap_entry_idx++;
}
}
}
void elf_file_clear_debug_info(ELFDebugInfo* debug_info) {
// clear debug info
memset(&debug_info->debug_link_info, 0, sizeof(ELFDebugLinkInfo));
// clear mmap
if(debug_info->mmap_entries) {
free(debug_info->mmap_entries);
debug_info->mmap_entries = NULL;
}
debug_info->mmap_entry_count = 0;
}
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