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Reduce FS reads while loading ELF files.

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This commit is contained in:
Enrico Fraccaroli
2021-12-17 18:21:10 +01:00
parent 151404d0d3
commit b8b4feeedd
3 changed files with 347 additions and 185 deletions
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mentos/inc/elf/elf.h
+8 -8
View File
@@ -80,21 +80,21 @@ typedef struct elf_header {
uint32_t entry;
/// Points to the start of the program header table.
uint32_t phoff;
/// TODO: Comment.
/// Points to the start of the section header table.
uint32_t shoff;
/// TODO: Comment.
/// Processor-specific flags.
uint32_t flags;
/// TODO: Comment.
/// Size of ELF header, in bytes.
uint16_t ehsize;
/// TODO: Comment.
/// Size of an entry in the program header table.
uint16_t phentsize;
/// TODO: Comment.
/// Number of entries in the program header table.
uint16_t phnum;
/// TODO: Comment.
/// Size of an entry in the section header table.
uint16_t shentsize;
/// TODO: Comment.
/// Number of entries in the section header table.
uint16_t shnum;
/// TODO: Comment.
/// Section header table index of sect name string table.
uint16_t shstrndx;
} elf_header_t;
mentos/src/drivers/ata.c
+1 -1
View File
@@ -11,7 +11,7 @@
/// Change the header.
#define __DEBUG_HEADER__ "[ATA ]"
/// Defines the debug level.
#define __DEBUG_LEVEL__ 100
//#define __DEBUG_LEVEL__ 100
#include "descriptor_tables/isr.h"
#include "hardware/pic8259.h"
mentos/src/elf/elf.c
+338 -176
View File
@@ -6,6 +6,7 @@
/// Change the header.
#define __DEBUG_HEADER__ "[ELF ]"
#define __DEBUG_LEVEL__ 100
#include "elf/elf.h"
@@ -18,27 +19,43 @@
#include "stdio.h"
#include "mem/slab.h"
#include "fs/vfs.h"
#include "assert.h"
/// @brief Reads the elf header from file.
/// @param file the file from which we extract the elf header.
/// @param header where we store the content we read.
/// @return true on success, false on failure.
static inline bool_t read_elf_header(vfs_file_t *file, elf_header_t *header)
{
size_t expected = sizeof(elf_header_t);
ssize_t nread = vfs_read(file, header, 0, expected);
if (nread != expected) {
pr_err("Failed to read elf header (read: %ld, expected: %ld)\n", nread, expected);
return false;
}
return true;
}
/// @brief Reads the program header from file.
/// @param file The file from which we extract the program header.
/// @param hdr A pointer to the ELF header.
/// @param header A pointer to the ELF header.
/// @param idx The index of the program header.
/// @param phdr Where we store the content we read.
/// @return The amount of bytes we read.
static inline ssize_t read_elf_program_header(vfs_file_t *file, elf_header_t *hdr, unsigned idx, elf_program_header_t *phdr)
static inline ssize_t read_elf_program_header(vfs_file_t *file, const elf_header_t *header, unsigned idx, elf_program_header_t *phdr)
{
return vfs_read(file, phdr, hdr->phoff + hdr->phentsize * idx, sizeof(elf_program_header_t));
return vfs_read(file, phdr, header->phoff + header->phentsize * idx, sizeof(elf_program_header_t));
}
/// @brief Reads the section header from file.
/// @param file The file from which we extract the section header.
/// @param hdr A pointer to the ELF header.
/// @param header A pointer to the ELF header.
/// @param idx The index of the section header.
/// @param shdr Where we store the content we read.
/// @return The amount of bytes we read.
static inline ssize_t read_elf_section_header(vfs_file_t *file, elf_header_t *hdr, unsigned idx, elf_section_header_t *shdr)
static inline ssize_t read_elf_section_header(vfs_file_t *file, const elf_header_t *header, unsigned idx, elf_section_header_t *shdr)
{
return vfs_read(file, shdr, hdr->shoff + hdr->shentsize * idx, sizeof(elf_program_header_t));
return vfs_read(file, shdr, header->shoff + header->shentsize * idx, sizeof(elf_section_header_t));
}
/// @brief Reads the symbol from file.
@@ -47,7 +64,7 @@ static inline ssize_t read_elf_section_header(vfs_file_t *file, elf_header_t *hd
/// @param idx The index of the symbol.
/// @param symbol Where we store the content we read.
/// @return The amount of bytes we read.
static inline ssize_t read_elf_symbol(vfs_file_t *file, elf_section_header_t *shdr, unsigned idx, elf_symbol_t *symbol)
static inline ssize_t read_elf_symbol(vfs_file_t *file, const elf_section_header_t *shdr, unsigned idx, elf_symbol_t *symbol)
{
// TODO: Here it should use `shdr->entsize`.
return vfs_read(file, symbol, shdr->offset + sizeof(elf_symbol_t) * idx, sizeof(elf_symbol_t));
@@ -59,209 +76,354 @@ static inline ssize_t read_elf_symbol(vfs_file_t *file, elf_section_header_t *sh
/// @param idx The index of the symbol.
/// @param symbol Where we store the content we read.
/// @return The amount of bytes we read.
static inline ssize_t read_elf_symbol_name(vfs_file_t *file, elf_section_header_t *shdr, unsigned offset, char *name, size_t name_len)
static inline ssize_t read_elf_symbol_name(vfs_file_t *file, const elf_section_header_t *shdr, unsigned offset, char *name, size_t name_len)
{
return vfs_read(file, name, shdr->offset + offset, name_len);
}
static inline int elf_find_section_header(vfs_file_t *file, elf_header_t *hdr, int type, elf_section_header_t *shdr)
/// @brief Reads all program headers from file.
/// @param file the file from which we extract the program header.
/// @param header a pointer to the ELF header.
/// @return The program headers, free them when finished.
static inline elf_program_header_t *read_elf_program_headers(vfs_file_t *file, const elf_header_t *header)
{
for (int i = 0; i < hdr->shnum; ++i) {
if (read_elf_section_header(file, hdr, i, shdr) == -1) {
pr_err("Failed to read section header at index %d.\n", i);
return -1;
}
if (shdr->type == type)
return 0;
memset(shdr, 0, sizeof(elf_section_header_t));
assert(sizeof(elf_program_header_t) == header->phentsize);
// Compute the size.
size_t size = header->phnum * header->phentsize;
// Allocate the memory for the headers.
elf_program_header_t *program_headers = (elf_program_header_t *)kmalloc(size);
if (program_headers == NULL) {
pr_err("Failed to allocate memory for program headers.\n");
return NULL;
}
return -1;
// Clean up the memory.
memset(program_headers, 0, size);
// Read the headers.
if (vfs_read(file, program_headers, header->phoff, size) != size) {
pr_err("Failed to read program headers.\n");
kfree(program_headers);
return NULL;
}
return program_headers;
}
static inline char *elf_get_strtable(vfs_file_t *file, elf_header_t *hdr, int ndx)
/// @brief Reads all section headers from file.
/// @param file the file from which we extract the section header.
/// @param header a pointer to the ELF header.
/// @return The section headers, free them when finished.
static inline elf_section_header_t *read_elf_section_headers(vfs_file_t *file, const elf_header_t *header)
{
if (ndx == SHT_NULL)
return NULL;
elf_section_header_t shdr;
if (read_elf_section_header(file, hdr, ndx, &shdr) == -1) {
pr_err("Failed to read section header at index %d.\n", ndx);
assert(sizeof(elf_section_header_t) == header->shentsize);
// Compute the size.
size_t size = header->shnum * header->shentsize;
// Allocate the memory for the headers.
elf_section_header_t *section_headers = (elf_section_header_t *)kmalloc(size);
if (section_headers == NULL) {
pr_err("Failed to allocate memory for section headers.\n");
return NULL;
}
char *strtable = kmalloc(shdr.size);
memset(strtable, 0, shdr.size);
if (vfs_read(file, strtable, shdr.offset, shdr.size) == -1) {
pr_err("Failed to read the string table at %d.\n", shdr.offset);
// Clean up the memory.
memset(section_headers, 0, size);
// Read the headers.
if (vfs_read(file, section_headers, header->shoff, size) != size) {
pr_err("Failed to read section headers.\n");
kfree(section_headers);
return NULL;
}
#if 0
dbg_putchar('{');
for (int i = 0; i < shdr.size; ++i) {
pr_debug("[%4d] `%c`", i, strtable[i]);
if (strtable[i] == 0)
pr_debug("\n");
}
dbg_putchar('}');
dbg_putchar('\n');
#endif
return strtable;
return section_headers;
}
static inline int elf_load_sigreturn(task_struct *task, vfs_file_t *file, elf_header_t *hdr)
static inline char *read_elf_strtable(
vfs_file_t *file,
const elf_header_t *header,
const elf_section_header_t *section_header)
{
elf_section_header_t shdr;
if (elf_find_section_header(file, hdr, SHT_SYMTAB, &shdr) == -1) {
pr_err("Cannot find the section header.\n");
return -1;
// Check if the header points to a string table.
if (section_header->type != SHT_STRTAB) {
pr_err("The header is not a STRTAB but a `%s` instead.\n", elf_type_to_string(section_header->type));
return NULL;
}
char *strtable = elf_get_strtable(file, hdr, shdr.link);
if (strtable == NULL) {
pr_err("Cannot fint the string table.\n");
return -1;
// Allocate the memory for the string table.
char *strtab = kmalloc(section_header->size);
// Initialize the memory.
memset(strtab, 0, section_header->size);
// Read the string table.
if (vfs_read(file, strtab, section_header->offset, section_header->size) != section_header->size) {
pr_err("Failed to read the string table at %d.\n", section_header->offset);
kfree(strtab);
return NULL;
}
uint32_t symtab_entries = shdr.size / sizeof(elf_symbol_t);
elf_symbol_t symbol;
for (int i = 0; i < symtab_entries; ++i) {
if (read_elf_symbol(file, &shdr, i, &symbol) == -1) {
pr_err("Failed to read the elf symbol at index %d.\n", i);
break;
}
if (strcmp(strtable + symbol.name, "sigreturn") == 0) {
task->sigreturn_eip = symbol.value;
pr_debug("Found `sigreturn` at index %d with EIP = %p.\n", i, symbol.value);
kfree(strtable);
return 0;
}
return strtab;
}
static inline elf_symbol_t *read_elf_symtable(
vfs_file_t *file,
const elf_header_t *header,
const elf_section_header_t *section_header)
{
// Check if the header points to a string table.
if (section_header->type != SHT_SYMTAB) {
pr_err("The header is not a SYMTAB but a `%s` instead.\n", elf_type_to_string(section_header->type));
return NULL;
}
pr_emerg("Failed to find `sigreturn`!\n");
kfree(strtable);
return -1;
if (sizeof(elf_symbol_t) != section_header->entsize) {
pr_err("Entities inside the symbol table have wrong size, %ld instead of %ld.\n",
section_header->entsize, sizeof(elf_symbol_t));
return NULL;
}
// Allocate the memory for the string table.
elf_symbol_t *symtab = kmalloc(section_header->size);
// Initialize the memory.
memset(symtab, 0, section_header->size);
// Read the string table.
if (vfs_read(file, symtab, section_header->offset, section_header->size) != section_header->size) {
pr_err("Failed to read the symbol table at %d.\n", section_header->offset);
kfree(symtab);
return NULL;
}
return symtab;
}
static inline const elf_section_header_t *elf_find_section_header(
const elf_header_t *header,
const elf_section_header_t *section_headers,
const char *shstrtab,
const char *name)
{
for (unsigned i = 0; i < header->shnum; ++i)
if (strcmp(shstrtab + section_headers[i].name, name) == 0)
return &section_headers[i];
return NULL;
}
static inline const elf_symbol_t *elf_find_symbol(
const elf_section_header_t *symbol_table_header,
const elf_symbol_t *symbol_table,
const char *symbol_table_strtab,
const char *name)
{
// Compute the entries in the symbol table.
uint32_t symtab_entries = symbol_table_header->size / sizeof(elf_symbol_t);
// Search the symbol.
for (unsigned i = 0; i < symtab_entries; ++i)
if (strcmp(symbol_table_strtab + symbol_table[i].name, name) == 0)
return &symbol_table[i];
return NULL;
}
static inline int elf_load_sigreturn(
const elf_section_header_t *symbol_table_header,
const elf_symbol_t *symbol_table,
const char *symbol_table_strtab,
task_struct *task)
{
const elf_symbol_t *sigreturn = elf_find_symbol(symbol_table_header, symbol_table, symbol_table_strtab, "sigreturn");
if (sigreturn == NULL) {
pr_err("Failed to find `sigreturn`!\n");
return false;
}
return true;
}
/// @brief Loads an ELF executable.
/// @param task The task for which we load the ELF.
/// @param file The ELF file.
/// @param hdr The header of the ELF file.
/// @param header The header of the ELF file.
/// @return The ELF entry.
static inline int elf_load_exec(task_struct *task, vfs_file_t *file, elf_header_t *hdr)
static inline int elf_load_exec(
task_struct *task,
vfs_file_t *file,
const elf_header_t *header,
const elf_program_header_t *phdrs)
{
elf_program_header_t phdr;
#if 0
pr_debug(" Type | Mem. Size | File Size | VADDR\n");
for (int idx = 0; idx < hdr->phnum; ++idx) {
for (unsigned i = 0; i < header->phnum; ++i) {
// Get the header.
if (read_elf_program_header(file, hdr, idx, &phdr) == -1) {
pr_err("Failed to read program header at index %d.\n", idx);
return -1;
}
pr_debug(" %-9s | %9s | %9s | 0x%08x - 0x%08x\n",
elf_type_to_string(phdr.type),
to_human_size(phdr.memsz),
to_human_size(phdr.filesz),
phdr.vaddr, phdr.vaddr + phdr.memsz);
if (phdr.type == PT_LOAD) {
uint32_t virt_addr = create_vm_area(task->mm, phdr.vaddr, phdr.memsz, MM_USER | MM_RW | MM_COW, GFP_KERNEL);
virt_map_page_t *vpage = virt_map_alloc(phdr.memsz);
uint32_t dst_addr = virt_map_vaddress(task->mm, vpage, virt_addr, phdr.memsz);
elf_type_to_string(phdrs[i].type),
to_human_size(phdrs[i].memsz),
to_human_size(phdrs[i].filesz),
phdrs[i].vaddr, phdrs[i].vaddr + phdrs[i].memsz);
if (phdrs[i].type == PT_LOAD) {
uint32_t virt_addr = create_vm_area(task->mm, phdrs[i].vaddr, phdrs[i].memsz, MM_USER | MM_RW | MM_COW, GFP_KERNEL);
virt_map_page_t *vpage = virt_map_alloc(phdrs[i].memsz);
uint32_t dst_addr = virt_map_vaddress(task->mm, vpage, virt_addr, phdrs[i].memsz);
// Load the memory area.
vfs_read(file, (void *)dst_addr, phdr.offset, phdr.filesz);
vfs_read(file, (void *)dst_addr, phdrs[i].offset, phdrs[i].filesz);
if (phdr.memsz > phdr.filesz) {
uint32_t zmem_sz = phdr.memsz - phdr.filesz;
memset((void *)(dst_addr + phdr.filesz), 0, zmem_sz);
if (phdrs[i].memsz > phdrs[i].filesz) {
uint32_t zmem_sz = phdrs[i].memsz - phdrs[i].filesz;
memset((void *)(dst_addr + phdrs[i].filesz), 0, zmem_sz);
}
virt_unmap_pg(vpage);
}
}
#endif
return 0;
}
static inline void dump_elf_section_headers(vfs_file_t *file, elf_header_t *hdr)
static inline void dump_elf_section_headers(
vfs_file_t *file,
const elf_header_t *header,
const elf_section_header_t *shdrs,
const char *shstrtab)
{
char *strtable = elf_get_strtable(file, hdr, hdr->shstrndx);
if (strtable == NULL)
return;
pr_debug("[Nr] Name Type Addr Off Size ES Flg Lk Inf Al\n");
elf_section_header_t shdr;
for (int i = 0; i < hdr->shnum; ++i) {
if (read_elf_section_header(file, hdr, i, &shdr) == -1) {
pr_err("Failed to read section header at index %d.\n", i);
}
for (int i = 0; i < header->shnum; ++i) {
pr_debug("[%2d] %-20s %-15s %08x %06x %06x %2u %3u %2u %3u %2u\n",
i, strtable + shdr.name, elf_section_header_type_to_string(shdr.type),
shdr.addr, shdr.offset, shdr.size,
shdr.entsize, shdr.flags, shdr.link, shdr.info, shdr.addralign);
i, shstrtab + shdrs[i].name, elf_section_header_type_to_string(shdrs[i].type),
shdrs[i].addr, shdrs[i].offset, shdrs[i].size,
shdrs[i].entsize, shdrs[i].flags, shdrs[i].link, shdrs[i].info, shdrs[i].addralign);
}
kfree(strtable);
}
static inline void dump_elf_symbol_table(vfs_file_t *file, elf_header_t *hdr)
static inline void dump_elf_symbol_table(
vfs_file_t *file,
const elf_header_t *header,
const elf_section_header_t *symtab_header,
const char *symtab_strtab)
{
elf_section_header_t shdr;
if (elf_find_section_header(file, hdr, SHT_SYMTAB, &shdr) == -1)
return;
char *strtable = elf_get_strtable(file, hdr, shdr.link);
if (strtable == NULL)
return;
// Count the number of entries.
uint32_t symtab_entries = shdr.size / sizeof(elf_symbol_t);
pr_debug("Symbol table '.symtab' contains %d entries (%d/%d):\n", symtab_entries, shdr.size, sizeof(elf_symbol_t));
// Count the number of entries.
uint32_t symtab_entries = symtab_header->size / sizeof(elf_symbol_t);
pr_debug("Symbol table '.symtab' contains %d entries (%d/%d):\n", symtab_entries, symtab_header->size, sizeof(elf_symbol_t));
pr_debug("[ Nr ] Value Size Type Bind Vis Ndx Name\n");
elf_symbol_t symbol;
for (int i = 0; i < symtab_entries; ++i) {
if (read_elf_symbol(file, &shdr, i, &symbol) == -1) {
if (read_elf_symbol(file, symtab_header, i, &symbol) == -1) {
pr_err("Failed to read the elf symbol at index %d.\n", i);
continue;
}
pr_debug("[%4d] %08x %5d %-7s %-6s %-8s %3d %s\n", i, symbol.value, symbol.size,
elf_symbol_type_to_string(ELF32_ST_TYPE(symbol.info)),
elf_symbol_bind_to_string(ELF32_ST_BIND(symbol.info)),
"-",
symbol.ndx,
strtable + symbol.name);
symtab_strtab + symbol.name);
}
kfree(strtable);
}
int elf_load_file(task_struct *task, vfs_file_t *file, uint32_t *entry)
{
// Open the file.
if (file == NULL) {
pr_err("Cannot find executable!");
if (file == NULL)
return false;
// Read the elf header.
elf_header_t header;
if (!read_elf_header(file, &header))
return false;
// Print header info.
pr_debug("Version : 0x%x\n", header.version);
pr_debug("Entry : 0x%x\n", header.entry);
pr_debug("Headers offset : 0x%x\n", header.phoff);
pr_debug("Headers count : %d\n", header.phnum);
// Check the elf header.
if (!elf_check_file_header(&header))
return false;
// Check if the elf file is an executable.
if (header.type != ET_EXEC) {
pr_err("Elf file is not an executable.\n");
return false;
}
// Load section headers.
elf_section_header_t *section_headers = read_elf_section_headers(file, &header);
if (section_headers == NULL) {
pr_err("Failed to load section headers.\n");
return false;
}
// Load program headers.
elf_program_header_t *program_headers = read_elf_program_headers(file, &header);
if (program_headers == NULL) {
pr_err("Failed to load program headers.\n");
goto free_section_headers;
}
// Get the header pointing to the section headers string table.
elf_section_header_t *shstrtab_hdr = &section_headers[header.shstrndx];
// Read the section headers string table.
char *shstrtab = read_elf_strtable(file, &header, shstrtab_hdr);
if (shstrtab == NULL) {
pr_err("Cannot retrieve the symbol table.\n");
goto free_program_headers;
}
// Find the symbol table header.
const elf_section_header_t *symtab_header = elf_find_section_header(&header, section_headers, shstrtab, ".symtab");
if (symtab_header == NULL) {
pr_err("Cannot find symbol table.\n");
goto free_string_table;
}
// Find the string table header associated with the symbol table header.
const elf_section_header_t *symtab_strtab_header = &section_headers[symtab_header->link];
if (symtab_strtab_header == NULL) {
pr_err("Cannot find strtab of symbol table.\n");
goto free_string_table;
}
// Load the symbol table.
elf_symbol_t *symtab = read_elf_symtable(file, &header, symtab_header);
if (symtab == NULL) {
pr_err("Cannot load symbol table.\n");
goto free_symbol_table_strtab;
}
// Read the symbol table section header.
char *symtab_strtab = read_elf_strtable(file, &header, symtab_strtab_header);
if (symtab_strtab == NULL) {
pr_err("Cannot retrieve the symbol table.\n");
goto free_symbol_table;
}
if (elf_load_sigreturn(symtab_header, symtab, symtab_strtab, task) == -1) {
pr_err("Failed to load `sigreturn`.\n");
goto free_symbol_table;
}
dump_elf_section_headers(file, &header, section_headers, shstrtab);
dump_elf_symbol_table(file, &header, symtab_header, symtab_strtab);
free_symbol_table:
kfree(symtab_strtab);
free_symbol_table_strtab:
kfree(symtab);
free_string_table:
kfree(shstrtab);
free_program_headers:
kfree(program_headers);
free_section_headers:
kfree(section_headers);
while (true) {}
#if 0
return false;
while (true) {}
//dump_elf_symbol_table(file, &header);
if (elf_load_exec(task, file, &header, phdrs) == -1) {
// Free up the memory.
kfree(shdrs);
kfree(phdrs);
return 0;
}
elf_header_t hdr;
// Set the reading position at the beginning of the file.
vfs_lseek(file, 0, SEEK_SET);
// Read the header.
if (vfs_read(file, &hdr, 0, sizeof(elf_header_t)) != -1) {
if (elf_check_file_header(&hdr)) {
pr_debug("Version : 0x%x\n", hdr.version);
pr_debug("Entry : 0x%x\n", hdr.entry);
pr_debug("Headers offset : 0x%x\n", hdr.phoff);
pr_debug("Headers count : %d\n", hdr.phnum);
//dump_elf_section_headers(file, &hdr);
//dump_elf_symbol_table(file, &hdr);
if (hdr.type == ET_EXEC) {
if (elf_load_sigreturn(task, file, &hdr) == -1) {
return 0;
}
if (elf_load_exec(task, file, &hdr) == -1) {
return 0;
}
// Set the entry.
(*entry) = hdr.entry;
return 1;
} else {
pr_err("ELF type not supported.\n");
}
} else {
pr_err("ELF file cannot be loaded.\n");
}
} else {
pr_err("Filed to read ELF header.\n");
}
return 0;
// Set the entry.
(*entry) = header.entry;
// Free up the memory.
kfree(shdrs);
kfree(phdrs);
while (true) {}
#endif
return 1;
}
int elf_check_file_type(vfs_file_t *file, Elf_Type type)
@@ -274,68 +436,68 @@ int elf_check_file_type(vfs_file_t *file, Elf_Type type)
// Set the reading position at the beginning of the file.
vfs_lseek(file, 0, SEEK_SET);
// Prepare the elf header.
elf_header_t hdr;
elf_header_t header;
// By default we return failure.
int ret = 0;
// Read the header and check the file type.
if (vfs_read(file, &hdr, 0, sizeof(elf_header_t)) != -1)
if (elf_check_file_header(&hdr))
ret = hdr.type == type;
if (vfs_read(file, &header, 0, sizeof(elf_header_t)) != -1)
if (elf_check_file_header(&header))
ret = header.type == type;
// Set the reading position at the beginning of the file.
vfs_lseek(file, 0, SEEK_SET);
return ret;
}
int elf_check_file_header(elf_header_t *hdr)
int elf_check_file_header(elf_header_t *header)
{
if (!elf_check_magic_number(hdr)) {
if (!elf_check_magic_number(header)) {
pr_err("Invalid ELF File.\n");
return 0;
return false;
}
if (hdr->ident[EI_CLASS] != ELFCLASS32) {
if (header->ident[EI_CLASS] != ELFCLASS32) {
pr_err("Unsupported ELF File Class.\n");
return 0;
return false;
}
if (hdr->ident[EI_DATA] != ELFDATA2LSB) {
if (header->ident[EI_DATA] != ELFDATA2LSB) {
pr_err("Unsupported ELF File byte order.\n");
return 0;
return false;
}
if (hdr->machine != EM_386) {
if (header->machine != EM_386) {
pr_err("Unsupported ELF File target.\n");
return 0;
return false;
}
if (hdr->ident[EI_VERSION] != EV_CURRENT) {
if (header->ident[EI_VERSION] != EV_CURRENT) {
pr_err("Unsupported ELF File version.\n");
return 0;
return false;
}
if (hdr->type != ET_EXEC) {
if (header->type != ET_EXEC) {
pr_err("Unsupported ELF File type.\n");
return 0;
return false;
}
return 1;
return true;
}
int elf_check_magic_number(elf_header_t *hdr)
int elf_check_magic_number(elf_header_t *header)
{
if (!hdr)
return 0;
if (hdr->ident[EI_MAG0] != ELFMAG0) {
if (!header)
return false;
if (header->ident[EI_MAG0] != ELFMAG0) {
pr_err("ELF Header EI_MAG0 incorrect.\n");
return 0;
return false;
}
if (hdr->ident[EI_MAG1] != ELFMAG1) {
if (header->ident[EI_MAG1] != ELFMAG1) {
pr_err("ELF Header EI_MAG1 incorrect.\n");
return 0;
return false;
}
if (hdr->ident[EI_MAG2] != ELFMAG2) {
if (header->ident[EI_MAG2] != ELFMAG2) {
pr_err("ELF Header EI_MAG2 incorrect.\n");
return 0;
return false;
}
if (hdr->ident[EI_MAG3] != ELFMAG3) {
if (header->ident[EI_MAG3] != ELFMAG3) {
pr_err("ELF Header EI_MAG3 incorrect.\n");
return 0;
return false;
}
return 1;
return true;
}
const char *elf_type_to_string(int type)