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Rewrite program loader.

This commit is contained in:
Jonas 'Sortie' Termansen 2014-06-26 01:05:07 +02:00
parent 261b95e0a6
commit bbf454e164
8 changed files with 3574 additions and 665 deletions
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768
kernel/elf.cpp
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@ -18,460 +18,382 @@
Sortix. If not, see <http://www.gnu.org/licenses/>.
elf.cpp
Constructs processes from ELF files.
Load a program in the Executable and Linkable Format into this process.
*******************************************************************************/
#include <sys/types.h>
#include <assert.h>
#include <elf.h>
#include <endian.h>
#include <errno.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <system-elf.h>
#include <__/wordsize.h>
#include <sortix/elf-note.h>
#include <sortix/mman.h>
#include <sortix/kernel/elf.h>
#include <sortix/kernel/kernel.h>
#include <sortix/kernel/memorymanagement.h>
#include <sortix/kernel/process.h>
#include <sortix/kernel/segment.h>
#include <sortix/kernel/symbol.h>
#include "elf.h"
namespace Sortix {
namespace ELF {
// TODO: This code doesn't respect that the size of program headers and section
// headers may vary depending on the ELF header and that using a simple
// table indexation isn't enough.
addr_t Construct32(Process* process, const uint8_t* file, size_t filelen,
Auxiliary* aux)
static bool is_power_of_two(uintptr_t value)
{
if ( filelen < sizeof(Header32) )
return 0;
const Header32* header = (const Header32*) file;
// Check for little endian.
if ( header->dataencoding != DATA2LSB )
return 0;
if ( header->version != CURRENTVERSION )
return 0;
addr_t entry = header->entry;
// Find the location of the program headers.
addr_t phtbloffset = header->programheaderoffset;
if ( filelen < phtbloffset )
return 0;
addr_t phtblpos = ((addr_t) file) + phtbloffset;
size_t phsize = header->programheaderentrysize;
const ProgramHeader32* phtbl = (const ProgramHeader32*) phtblpos;
// Validate that all program headers are present.
uint16_t numprogheaders = header->numprogramheaderentries;
size_t neededfilelen = phtbloffset + numprogheaders * phsize;
if ( filelen < neededfilelen )
return 0;
// Prepare the process for execution (clean up address space, etc.)
process->ResetForExecute();
// Flush the TLB such that no stale information from the last
// address space is used when creating the new one.
Memory::Flush();
// Create all the segments in the final process.
// TODO: Handle errors on bad/malicious input or out-of-mem!
for ( uint16_t i = 0; i < numprogheaders; i++ )
{
const ProgramHeader32* pht = &(phtbl[i]);
if ( pht->type == PT_TLS )
{
aux->tls_file_offset = pht->offset;
aux->tls_file_size = pht->filesize;
aux->tls_mem_size = pht->memorysize;
aux->tls_mem_align = pht->align;
continue;
}
if ( pht->type == PT_NOTE )
{
uintptr_t notes_addr = (uintptr_t) file + pht->offset;
size_t notes_offset = 0;
while ( notes_offset < pht->filesize )
{
uintptr_t note = notes_addr + notes_offset;
uint32_t namesz = *(uint32_t*) (note + 0);
uint32_t descsz = *(uint32_t*) (note + 4);
uint32_t type = *(uint32_t*) (note + 8);
uint32_t namesz_aligned = -(-namesz & ~(4U - 1));
uint32_t descsz_aligned = -(-descsz & ~(4U - 1));
size_t note_size = 12 + namesz_aligned + descsz_aligned;
notes_offset += note_size;
const char* name = (const char*) (note + 12);
uintptr_t desc = note + 12 + namesz_aligned;
if ( strcmp(name, "Sortix") == 0 )
{
if ( type == ELF_NOTE_SORTIX_UTHREAD_SIZE )
{
aux->uthread_size = *(uint32_t*) (desc + 0);
aux->uthread_align = *(uint32_t*) (desc + 4);
}
}
}
continue;
}
if ( pht->type != PT_LOAD )
continue;
addr_t virtualaddr = pht->virtualaddr;
addr_t mapto = Page::AlignDown(virtualaddr);
addr_t mapbytes = virtualaddr - mapto + pht->memorysize;
assert(pht->offset % pht->align == virtualaddr % pht->align);
assert(pht->offset + pht->filesize < filelen);
assert(pht->filesize <= pht->memorysize);
int prot = PROT_FORK | PROT_KREAD | PROT_KWRITE;
if ( pht->flags & PF_X ) { prot |= PROT_EXEC; }
if ( pht->flags & PF_R ) { prot |= PROT_READ; }
if ( pht->flags & PF_W ) { prot |= PROT_WRITE; }
struct segment segment;
segment.addr = mapto;
segment.size = Page::AlignUp(mapbytes);
segment.prot = prot;
kthread_mutex_lock(&process->segment_lock);
if ( !IsUserspaceSegment(&segment) ||
IsSegmentOverlapping(process, &segment) )
{
kthread_mutex_unlock(&process->segment_lock);
process->ResetAddressSpace();
return 0;
}
assert(process == CurrentProcess());
if ( !Memory::MapRange(segment.addr, segment.size, prot, PAGE_USAGE_USER_SPACE) )
{
kthread_mutex_unlock(&process->segment_lock);
process->ResetAddressSpace();
return 0;
}
if ( !AddSegment(process, &segment) )
{
Memory::UnmapRange(segment.addr, segment.size, PAGE_USAGE_USER_SPACE);
kthread_mutex_unlock(&process->segment_lock);
process->ResetAddressSpace();
return 0;
}
kthread_mutex_unlock(&process->segment_lock);
// Copy as much data as possible and memset the rest to 0.
uint8_t* memdest = (uint8_t*) virtualaddr;
uint8_t* memsource = (uint8_t*) (((addr_t)file) + pht->offset);
memcpy(memdest, memsource, pht->filesize);
memset(memdest + pht->filesize, 0, pht->memorysize - pht->filesize);
}
// Find the location of the section headers.
addr_t shtblpos = (addr_t) file + header->sectionheaderoffset;
const SectionHeader32* shtbl = (const SectionHeader32*) shtblpos;
const SectionHeader32* section_names_section = shtbl + header->sectionheaderstringindex;
const char* section_names = (const char*) (file + section_names_section->offset);
// Find the string table.
const SectionHeader32* string_table_section = NULL;
for ( size_t i = 0; i < header->numsectionheaderentries; i++ )
if ( !strcmp(section_names + shtbl[i].name, ".strtab") )
{
string_table_section = shtbl + i;
break;
}
// Find the symbol table.
const SectionHeader32* symbol_table_section = NULL;
for ( size_t i = 0; i < header->numsectionheaderentries; i++ )
if ( !strcmp(section_names + shtbl[i].name, ".symtab") )
{
symbol_table_section = shtbl + i;
break;
}
if ( !string_table_section || !symbol_table_section )
return entry;
// Prepare copying debug information.
const char* elf_string_table = (const char*) (file + string_table_section->offset);
size_t elf_string_table_size = string_table_section->size;
const Symbol32* elf_symbols = (const Symbol32*) (file + symbol_table_section->offset);
size_t elf_symbol_count = symbol_table_section->size / sizeof(Symbol32);
// Duplicate the string table.
char* string_table = new char[elf_string_table_size];
if ( !string_table )
return entry;
memcpy(string_table, elf_string_table, elf_string_table_size);
// Duplicate the symbol table.
Symbol* symbol_table = new Symbol[elf_symbol_count-1];
if ( !symbol_table )
{
delete[] string_table;
return entry;
}
// Copy all entires except the leading null entry.
for ( size_t i = 1; i < elf_symbol_count; i++ )
{
symbol_table[i-1].address = elf_symbols[i].st_value;
symbol_table[i-1].size = elf_symbols[i].st_size;
symbol_table[i-1].name = string_table + elf_symbols[i].st_name;
}
process->string_table = string_table;
process->string_table_length = elf_string_table_size;
process->symbol_table = symbol_table;
process->symbol_table_length = elf_symbol_count-1;
return entry;
for ( uintptr_t i = 0; i < sizeof(uintptr_t) * 8; i++ )
if ( (uintptr_t) 1 << i == value )
return true;
return false;
}
addr_t Construct64(Process* process, const uint8_t* file, size_t filelen,
Auxiliary* aux)
uintptr_t Load(const void* file_ptr, size_t file_size, Auxiliary* aux)
{
#if !defined(__x86_64__)
(void) process;
(void) file;
(void) filelen;
(void) aux;
return errno = ENOEXEC, 0;
#else
if ( filelen < sizeof(Header64) )
return 0;
const Header64* header = (const Header64*) file;
// Check for little endian.
if ( header->dataencoding != DATA2LSB )
return 0;
if ( header->version != CURRENTVERSION )
return 0;
addr_t entry = header->entry;
// Find the location of the program headers.
addr_t phtbloffset = header->programheaderoffset;
if ( filelen < phtbloffset )
return 0;
addr_t phtblpos = ((addr_t) file) + phtbloffset;
size_t phsize = header->programheaderentrysize;
const ProgramHeader64* phtbl = (const ProgramHeader64*) phtblpos;
// Validate that all program headers are present.
uint16_t numprogheaders = header->numprogramheaderentries;
size_t neededfilelen = phtbloffset + numprogheaders * phsize;
if ( filelen < neededfilelen )
return 0;
// Prepare the process for execution (clean up address space, etc.)
process->ResetForExecute();
// Flush the TLB such that no stale information from the last
// address space is used when creating the new one.
Memory::Flush();
// Create all the segments in the final process.
// TODO: Handle errors on bad/malicious input or out-of-mem!
for ( uint16_t i = 0; i < numprogheaders; i++ )
{
const ProgramHeader64* pht = &(phtbl[i]);
if ( pht->type == PT_TLS )
{
aux->tls_file_offset = pht->offset;
aux->tls_file_size = pht->filesize;
aux->tls_mem_size = pht->memorysize;
aux->tls_mem_align = pht->align;
continue;
}
if ( pht->type == PT_NOTE )
{
uintptr_t notes_addr = (uintptr_t) file + pht->offset;
size_t notes_offset = 0;
while ( notes_offset < pht->filesize )
{
uintptr_t note = notes_addr + notes_offset;
uint32_t namesz = *(uint32_t*) (note + 0);
uint32_t descsz = *(uint32_t*) (note + 4);
uint32_t type = *(uint32_t*) (note + 8);
uint32_t namesz_aligned = -(-namesz & ~(4U - 1));
uint32_t descsz_aligned = -(-descsz & ~(4U - 1));
size_t note_size = 12 + namesz_aligned + descsz_aligned;
notes_offset += note_size;
const char* name = (const char*) (note + 12);
uintptr_t desc = note + 12 + namesz_aligned;
if ( strcmp(name, "Sortix") == 0 )
{
if ( type == ELF_NOTE_SORTIX_UTHREAD_SIZE )
{
uint64_t size_low = *((uint32_t*) (desc + 0));
uint64_t size_high = *((uint32_t*) (desc + 4));
aux->uthread_size = size_low << 0 | size_high << 32;
uint64_t align_low = *((uint32_t*) (desc + 8));
uint64_t align_high = *((uint32_t*) (desc + 12));
aux->uthread_align = align_low << 0 | align_high << 32;
}
}
}
continue;
}
if ( pht->type != PT_LOAD )
continue;
addr_t virtualaddr = pht->virtualaddr;
addr_t mapto = Page::AlignDown(virtualaddr);
addr_t mapbytes = virtualaddr - mapto + pht->memorysize;
assert(pht->offset % pht->align == virtualaddr % pht->align);
assert(pht->offset + pht->filesize < filelen);
assert(pht->filesize <= pht->memorysize);
int prot = PROT_FORK | PROT_KREAD | PROT_KWRITE;
if ( pht->flags & PF_X ) { prot |= PROT_EXEC; }
if ( pht->flags & PF_R ) { prot |= PROT_READ; }
if ( pht->flags & PF_W ) { prot |= PROT_WRITE; }
struct segment segment;
segment.addr = mapto;
segment.size = Page::AlignUp(mapbytes);
segment.prot = prot;
kthread_mutex_lock(&process->segment_lock);
if ( !IsUserspaceSegment(&segment) ||
IsSegmentOverlapping(process, &segment) )
{
kthread_mutex_unlock(&process->segment_lock);
process->ResetAddressSpace();
return 0;
}
assert(process == CurrentProcess());
if ( !Memory::MapRange(segment.addr, segment.size, prot, PAGE_USAGE_USER_SPACE) )
{
kthread_mutex_unlock(&process->segment_lock);
process->ResetAddressSpace();
return 0;
}
if ( !AddSegment(process, &segment) )
{
Memory::UnmapRange(segment.addr, segment.size, PAGE_USAGE_USER_SPACE);
kthread_mutex_unlock(&process->segment_lock);
process->ResetAddressSpace();
return 0;
}
kthread_mutex_unlock(&process->segment_lock);
// Copy as much data as possible and memset the rest to 0.
uint8_t* memdest = (uint8_t*) virtualaddr;
uint8_t* memsource = (uint8_t*) (((addr_t)file) + pht->offset);
memcpy(memdest, memsource, pht->filesize);
memset(memdest + pht->filesize, 0, pht->memorysize - pht->filesize);
}
// Find the location of the section headers.
addr_t shtblpos = (addr_t) file + header->sectionheaderoffset;
const SectionHeader64* shtbl = (const SectionHeader64*) shtblpos;
const SectionHeader64* section_names_section = shtbl + header->sectionheaderstringindex;
const char* section_names = (const char*) (file + section_names_section->offset);
// Find the string table.
const SectionHeader64* string_table_section = NULL;
for ( size_t i = 0; i < header->numsectionheaderentries; i++ )
if ( !strcmp(section_names + shtbl[i].name, ".strtab") )
{
string_table_section = shtbl + i;
break;
}
// Find the symbol table.
const SectionHeader64* symbol_table_section = NULL;
for ( size_t i = 0; i < header->numsectionheaderentries; i++ )
if ( !strcmp(section_names + shtbl[i].name, ".symtab") )
{
symbol_table_section = shtbl + i;
break;
}
if ( !string_table_section || !symbol_table_section )
return entry;
// Prepare copying debug information.
const char* elf_string_table = (const char*) (file + string_table_section->offset);
size_t elf_string_table_size = string_table_section->size;
const Symbol64* elf_symbols = (const Symbol64*) (file + symbol_table_section->offset);
size_t elf_symbol_count = symbol_table_section->size / sizeof(Symbol64);
// Duplicate the string table.
char* string_table = new char[elf_string_table_size];
if ( !string_table )
return entry;
memcpy(string_table, elf_string_table, elf_string_table_size);
// Duplicate the symbol table.
Symbol* symbol_table = new Symbol[elf_symbol_count-1];
if ( !symbol_table )
{
delete[] string_table;
return entry;
}
// Copy all entires except the leading null entry.
for ( size_t i = 1; i < elf_symbol_count; i++ )
{
symbol_table[i-1].address = elf_symbols[i].st_value;
symbol_table[i-1].size = elf_symbols[i].st_size;
symbol_table[i-1].name = string_table + elf_symbols[i].st_name;
}
process->string_table = string_table;
process->string_table_length = elf_string_table_size;
process->symbol_table = symbol_table;
process->symbol_table_length = elf_symbol_count-1;
return entry;
#endif
}
addr_t Construct(Process* process, const void* file, size_t filelen,
Auxiliary* aux)
{
if ( filelen < sizeof(Header) )
return errno = ENOEXEC, 0;
const Header* header = (const Header*) file;
if ( !(header->magic[0] == 0x7F && header->magic[1] == 'E' &&
header->magic[2] == 'L' && header->magic[3] == 'F' ) )
return errno = ENOEXEC, 0;
memset(aux, 0, sizeof(*aux));
switch ( header->fileclass )
Process* process = CurrentProcess();
uintptr_t userspace_addr;
size_t userspace_size;
Memory::GetUserVirtualArea(&userspace_addr, &userspace_size);
uintptr_t userspace_end = userspace_addr + userspace_size;
const unsigned char* file = (const unsigned char*) file_ptr;
if ( file_size < EI_NIDENT )
return errno = ENOEXEC, 0;
if ( memcmp(file, ELFMAG, SELFMAG) != 0 )
return errno = ENOEXEC, 0;
#if __WORDSIZE == 32
if ( file[EI_CLASS] != ELFCLASS32 )
return errno = EINVAL, 0;
#elif __WORDSIZE == 64
if ( file[EI_CLASS] != ELFCLASS64 )
return errno = EINVAL, 0;
#else
#error "You need to add support for your elf class."
#endif
#if BYTE_ORDER == LITTLE_ENDIAN
if ( file[EI_DATA] != ELFDATA2LSB )
return errno = EINVAL, 0;
#elif BYTE_ORDER == BIG_ENDIAN
if ( file[EI_DATA] != ELFDATA2MSB )
return errno = EINVAL, 0;
#else
#error "You need to add support for your endian."
#endif
if ( file[EI_VERSION] != EV_CURRENT )
return errno = EINVAL, 0;
if ( file[EI_OSABI] != ELFOSABI_SORTIX )
return errno = EINVAL, 0;
if ( file[EI_ABIVERSION] != 0 )
return errno = EINVAL, 0;
if ( file_size < sizeof(Elf_Ehdr) )
return errno = EINVAL, 0;
if ( (uintptr_t) file & (alignof(Elf_Ehdr) - 1) )
return errno = EINVAL, 0;
const Elf_Ehdr* header = (const Elf_Ehdr*) file;
if ( header->e_ehsize < sizeof(Elf_Ehdr) )
return errno = EINVAL, 0;
if ( file_size < header->e_ehsize )
return errno = EINVAL, 0;
#if defined(__i386__)
if ( header->e_machine != EM_386 )
return errno = EINVAL, 0;
#elif defined(__x86_64__)
if ( header->e_machine != EM_X86_64 )
return errno = EINVAL, 0;
#else
#error "Please recognize your processor in e_machine."
#endif
if ( header->e_type != ET_EXEC )
return errno = EINVAL, 0;
if ( header->e_entry == 0 )
return errno = EINVAL, 0;
if ( file_size < header->e_phoff )
return errno = EINVAL, 0;
if ( file_size < header->e_shoff )
return errno = EINVAL, 0;
if ( header->e_phentsize < sizeof(Elf_Phdr) )
return errno = EINVAL, 0;
if ( header->e_shentsize < sizeof(Elf_Shdr) )
return errno = EINVAL, 0;
process->ResetForExecute();
if ( header->e_phnum == (Elf_Half) -1 )
return errno = EINVAL, 0;
if ( header->e_shnum == (Elf_Half) -1 )
return errno = EINVAL, 0;
for ( Elf32_Half i = 0; i < header->e_phnum; i++ )
{
case CLASS32: return Construct32(process, (const uint8_t*) file, filelen, aux);
case CLASS64: return Construct64(process, (const uint8_t*) file, filelen, aux);
default:
return 0;
size_t max_phs = (file_size - header->e_phoff) / header->e_phentsize;
if ( max_phs <= i )
return errno = EINVAL, 0;
size_t pheader_offset = header->e_phoff + i * header->e_phentsize;
if ( (uintptr_t) (file + pheader_offset) & (alignof(Elf_Phdr) - 1) )
return errno = EINVAL, 0;
Elf_Phdr* pheader = (Elf_Phdr*) (file + pheader_offset);
switch ( pheader->p_type )
{
case PT_TLS: break;
case PT_NOTE: break;
case PT_LOAD: break;
default: continue;
};
if ( !is_power_of_two(pheader->p_align) )
return errno = EINVAL, 0;
if ( file_size < pheader->p_offset )
return errno = EINVAL, 0;
if ( file_size - pheader->p_offset < pheader->p_filesz )
return errno = EINVAL, 0;
if ( pheader->p_type == PT_TLS )
{
if ( pheader->p_memsz < pheader->p_filesz )
return errno = EINVAL, 0;
aux->tls_file_offset = pheader->p_offset;
aux->tls_file_size = pheader->p_filesz;
aux->tls_mem_size = pheader->p_memsz;
aux->tls_mem_align = pheader->p_align;
continue;
}
if ( pheader->p_type == PT_NOTE )
{
size_t notes_offset = 0;
while ( notes_offset < pheader->p_filesz )
{
size_t available = pheader->p_filesz - notes_offset;
size_t note_header_size = 3 * sizeof(uint32_t);
if ( available < note_header_size )
return errno = EINVAL, 0;
available -= note_header_size;
size_t file_offset = pheader->p_offset + notes_offset;
if ( ((uintptr_t) file + file_offset) & (alignof(uint32_t) - 1) )
return errno = EINVAL, 0;
const unsigned char* note = file + file_offset;
uint32_t* note_header = (uint32_t*) note;
uint32_t namesz = note_header[0];
uint32_t descsz = note_header[1];
uint32_t type = note_header[2];
uint32_t namesz_aligned = -(-namesz & ~(sizeof(uint32_t) - 1));
uint32_t descsz_aligned = -(-descsz & ~(sizeof(uint32_t) - 1));
if ( available < namesz_aligned )
return errno = EINVAL, 0;
available -= namesz_aligned;
if ( available < descsz_aligned )
return errno = EINVAL, 0;
available -= descsz_aligned;
notes_offset += note_header_size + namesz_aligned + descsz_aligned;
const char* name = (const char*) (note + note_header_size);
if ( strnlen(name, namesz_aligned) == namesz_aligned )
return errno = EINVAL, 0;
const unsigned char* desc = note + note_header_size + namesz_aligned;
const uint32_t* desc_32bits = (const uint32_t*) desc;
if ( strcmp(name, ELF_NOTE_SORTIX) == 0 )
{
if ( type == ELF_NOTE_SORTIX_UTHREAD_SIZE )
{
if ( descsz_aligned != 2 * sizeof(size_t) )
return errno = EINVAL, 0;
#if __WORDSIZE == 32
aux->uthread_size = desc_32bits[0];
aux->uthread_align = desc_32bits[1];
#elif __WORDSIZE == 64 && BYTE_ORDER == LITTLE_ENDIAN
aux->uthread_size = (uint64_t) desc_32bits[0] << 0 |
(uint64_t) desc_32bits[1] << 32;
aux->uthread_align = (uint64_t) desc_32bits[2] << 0 |
(uint64_t) desc_32bits[3] << 32;
#elif __WORDSIZE == 64 && BYTE_ORDER == BIG_ENDIAN
aux->uthread_size = (uint64_t) desc_32bits[1] << 0 |
(uint64_t) desc_32bits[0] << 32;
aux->uthread_align = (uint64_t) desc_32bits[3] << 0 |
(uint64_t) desc_32bits[2] << 32;
#else
#error "You need to correctly read the uthread note"
#endif
if ( !is_power_of_two(aux->uthread_align) )
return errno = EINVAL, 0;
}
}
}
continue;
}
if ( pheader->p_type == PT_LOAD )
{
if ( pheader->p_filesz &&
pheader->p_vaddr % pheader->p_align !=
pheader->p_offset % pheader->p_align )
return errno = EINVAL, 0;
int prot = PROT_FORK | PROT_KREAD | PROT_KWRITE;
if ( pheader->p_flags & PF_X )
prot |= PROT_EXEC;
if ( pheader->p_flags & PF_R )
prot |= PROT_READ;
if ( pheader->p_flags & PF_W )
prot |= PROT_WRITE;
if ( pheader->p_vaddr < userspace_addr )
return errno = EINVAL, 0;
if ( userspace_end < pheader->p_vaddr )
return errno = EINVAL, 0;
if ( userspace_end - pheader->p_vaddr < pheader->p_memsz )
return errno = EINVAL, 0;
uintptr_t map_start = Page::AlignDown(pheader->p_vaddr);
uintptr_t map_end = Page::AlignUp(pheader->p_vaddr + pheader->p_memsz);
size_t map_size = map_end - map_start;
struct segment segment;
segment.addr = map_start;
segment.size = map_size;
segment.prot = prot;
assert(IsUserspaceSegment(&segment));
kthread_mutex_lock(&process->segment_lock);
if ( IsSegmentOverlapping(process, &segment) )
{
kthread_mutex_unlock(&process->segment_lock);
return errno = EINVAL, 0;
}
if ( !Memory::MapRange(segment.addr, segment.size, prot, PAGE_USAGE_USER_SPACE) )
{
kthread_mutex_unlock(&process->segment_lock);
return errno = EINVAL, 0;
}
if ( !AddSegment(process, &segment) )
{
Memory::UnmapRange(segment.addr, segment.size, PAGE_USAGE_USER_SPACE);
kthread_mutex_unlock(&process->segment_lock);
return errno = EINVAL, 0;
}
kthread_mutex_unlock(&process->segment_lock);
memset((void*) segment.addr, 0, segment.size);
memcpy((void*) pheader->p_vaddr, file + pheader->p_offset, pheader->p_filesz);
}
}
// SECURITY: TODO: Insecure.
Elf_Shdr* section_string_table_section = (Elf_Shdr*) (file + header->e_shoff + header->e_shstrndx * header->e_shentsize);
const char* section_string_table = (const char*) (file + section_string_table_section->sh_offset);
//size_t section_string_table_size = section_string_table_section->sh_size;
const char* string_table = NULL;
size_t string_table_size = 0;
for ( Elf32_Half i = 0; i < header->e_shnum; i++ )
{
size_t max_shs = (file_size - header->e_shoff) / header->e_shentsize;
if ( max_shs <= i )
return errno = EINVAL, 0;
size_t sheader_offset = header->e_shoff + i * header->e_shentsize;
if ( (uintptr_t) (file + sheader_offset) & (alignof(Elf_Shdr) - 1) )
return errno = EINVAL, 0;
Elf_Shdr* sheader = (Elf_Shdr*) (file + sheader_offset);
// SECURITY: TODO: Insecure.
const char* section_name = section_string_table + sheader->sh_name;
if ( !strcmp(section_name, ".strtab") )
{
// SECURITY: TODO: Insecure.
string_table = (const char*) (file + sheader->sh_offset);
string_table_size = sheader->sh_size;
}
}
for ( Elf32_Half i = 0; i < header->e_shnum; i++ )
{
size_t sheader_offset = header->e_shoff + i * header->e_shentsize;
Elf_Shdr* sheader = (Elf_Shdr*) (file + sheader_offset);
// SECURITY: TODO: Insecure.
const char* section_name = section_string_table + sheader->sh_name;
if ( !strcmp(section_name, ".symtab") )
{
if ( process->symbol_table )
continue;
// SECURITY: TODO: Insecure.
Elf_Sym* symbols = (Elf_Sym*) (file + sheader->sh_offset);
size_t symbols_length = sheader->sh_size / sizeof(Elf_Sym);
if ( symbols_length == 0 )
continue;
symbols++;
symbols_length--;
char* string_table_copy = new char[string_table_size];
if ( !string_table_copy )
continue;
memcpy(string_table_copy, string_table, string_table_size);
Symbol* symbols_copy = new Symbol[symbols_length];
if ( !symbols_copy )
{
delete[] string_table_copy;
continue;
}
for ( size_t i = 0; i < symbols_length; i++ )
{
memset(&symbols_copy[i], 0, sizeof(symbols_copy[i]));
symbols_copy[i].address = symbols[i].st_value;
symbols_copy[i].size = symbols[i].st_size;
// SECURITY: TODO: Insecure.
symbols_copy[i].name = string_table_copy + symbols[i].st_name;
}
process->string_table = string_table_copy;
process->string_table_length = string_table_size;
process->symbol_table = symbols_copy;
process->symbol_table_length = symbols_length;
}
}
return header->e_entry;
}
} // namespace ELF

211
kernel/elf.h
View File

@ -1,211 +0,0 @@
/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013.
This file is part of Sortix.
Sortix is free software: you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.
Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
details.
You should have received a copy of the GNU General Public License along with
Sortix. If not, see <http://www.gnu.org/licenses/>.
elf.h
Constructs processes from ELF files.
*******************************************************************************/
#ifndef SORTIX_ELF_H
#define SORTIX_ELF_H
#include <stddef.h>
#include <stdint.h>
namespace Sortix {
class Process;
namespace ELF {
struct Auxiliary
{
size_t tls_file_offset;
size_t tls_file_size;
size_t tls_mem_size;
size_t tls_mem_align;
size_t uthread_size;
size_t uthread_align;
};
struct Header
{
unsigned char magic[4];
unsigned char fileclass;
unsigned char dataencoding;
unsigned char version;
unsigned char osabi;
unsigned char abiversion;
unsigned char padding[7];
};
const unsigned char CLASSNONE = 0;
const unsigned char CLASS32 = 1;
const unsigned char CLASS64 = 2;
const unsigned char DATA2LSB = 1;
const unsigned char DATA2MSB = 2;
const unsigned char CURRENTVERSION = 1;
struct Header32 : public Header
{
uint16_t type;
uint16_t machine;
uint32_t version;
uint32_t entry;
uint32_t programheaderoffset;
uint32_t sectionheaderoffset;
uint32_t flags;
uint16_t elfheadersize;
uint16_t programheaderentrysize;
uint16_t numprogramheaderentries;
uint16_t sectionheaderentrysize;
uint16_t numsectionheaderentries;
uint16_t sectionheaderstringindex;
};
struct Header64 : public Header
{
uint16_t type;
uint16_t machine;
uint32_t version;
uint64_t entry;
uint64_t programheaderoffset;
uint64_t sectionheaderoffset;
uint32_t flags;
uint16_t elfheadersize;
uint16_t programheaderentrysize;
uint16_t numprogramheaderentries;
uint16_t sectionheaderentrysize;
uint16_t numsectionheaderentries;
uint16_t sectionheaderstringindex;
};
struct SectionHeader32
{
uint32_t name;
uint32_t type;
uint32_t flags;
uint32_t addr;
uint32_t offset;
uint32_t size;
uint32_t link;
uint32_t info;
uint32_t addralign;
uint32_t entsize;
};
struct SectionHeader64
{
uint32_t name;
uint32_t type;
uint64_t flags;
uint64_t addr;
uint64_t offset;
uint64_t size;
uint32_t link;
uint32_t info;
uint64_t addralign;
uint64_t entsize;
};
const uint32_t SHT_NULL = 0;
const uint32_t SHT_PROGBITS = 1;
const uint32_t SHT_SYMTAB = 2;
const uint32_t SHT_STRTAB = 3;
const uint32_t SHT_RELA = 4;
const uint32_t SHT_HASH = 5;
const uint32_t SHT_DYNAMIC = 6;
const uint32_t SHT_NOTE = 7;
const uint32_t SHT_NOBITS = 8;
const uint32_t SHT_REL = 9;
const uint32_t SHT_SHLIB = 10;
const uint32_t SHT_DYNSYM = 11;
const uint32_t SHT_LOPROC = 0x70000000;
const uint32_t SHT_HIPROC = 0x7fffffff;
const uint32_t SHT_LOUSER = 0x80000000;
const uint32_t SHT_HIUSER = 0xffffffff;
struct ProgramHeader32
{
uint32_t type;
uint32_t offset;
uint32_t virtualaddr;
uint32_t physicaladdr;
uint32_t filesize;
uint32_t memorysize;
uint32_t flags;
uint32_t align;
};
struct ProgramHeader64
{
uint32_t type;
uint32_t flags;
uint64_t offset;
uint64_t virtualaddr;
uint64_t physicaladdr;
uint64_t filesize;
uint64_t memorysize;
uint64_t align;
};
const uint32_t PT_NULL = 0;
const uint32_t PT_LOAD = 1;
const uint32_t PT_DYNAMIC = 2;
const uint32_t PT_INTERP = 3;
const uint32_t PT_NOTE = 4;
const uint32_t PT_SHLIB = 5;
const uint32_t PT_PHDR = 6;
const uint32_t PT_TLS = 7;
const uint32_t PT_LOPROC = 0x70000000;
const uint32_t PT_HIPROC = 0x7FFFFFFF;
const uint32_t PF_X = 1 << 0;
const uint32_t PF_W = 1 << 1;
const uint32_t PF_R = 1 << 2;
struct Symbol32
{
uint32_t st_name;
uint32_t st_value;
uint32_t st_size;
uint8_t st_info;
uint8_t st_other;
uint16_t st_shndx;
};
struct Symbol64
{
uint32_t st_name;
uint8_t st_info;
uint8_t st_other;
uint16_t st_shndx;
uint64_t st_value;
uint64_t st_size;
};
// Reads the elf file into the current address space and returns the entry
// address of the program, or 0 upon failure.
addr_t Construct(Process* process, const void* file, size_t filelen,
Auxiliary* aux);
} // namespace ELF
} // namespace Sortix
#endif

33
kernel/include/sortix/elf-note.h → kernel/include/sortix/kernel/elf.h
View File

@ -1,6 +1,6 @@
/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2014.
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013, 2014.
This file is part of Sortix.
@ -17,20 +17,35 @@
You should have received a copy of the GNU General Public License along with
Sortix. If not, see <http://www.gnu.org/licenses/>.
sortix/elf-note.h
Declares type constants for the Sortix ELF notes.
sortix/kernel/elf.h
Executable and Linkable Format.
*******************************************************************************/
#ifndef INCLUDE_SORTIX_ELF_NOTE_H
#define INCLUDE_SORTIX_ELF_NOTE_H
#ifndef INCLUDE_SORTIX_KERNEL_ELF_H
#define INCLUDE_SORTIX_KERNEL_ELF_H
#include <sys/cdefs.h>
#include <stddef.h>
#include <stdint.h>
__BEGIN_DECLS
namespace Sortix {
namespace ELF {
#define ELF_NOTE_SORTIX_UTHREAD_SIZE 0x10
struct Auxiliary
{
size_t tls_file_offset;
size_t tls_file_size;
size_t tls_mem_size;
size_t tls_mem_align;
size_t uthread_size;
size_t uthread_align;
};
__END_DECLS
// Reads the elf file into the current address space and returns the entry
// address of the program, or 0 upon failure.
uintptr_t Load(const void* file, size_t filelen, Auxiliary* aux);
} // namespace ELF
} // namespace Sortix
#endif

34
kernel/kernel.cpp
View File

@ -27,6 +27,7 @@
#include <assert.h>
#include <brand.h>
#include <elf.h>
#include <errno.h>
#include <malloc.h>
#include <stddef.h>
@ -69,7 +70,6 @@
#include "ata.h"
#include "com.h"
#include "elf.h"
#include "fs/full.h"
#include "fs/kram.h"
#include "fs/null.h"
@ -306,11 +306,11 @@ extern "C" void KernelInit(unsigned long magic, multiboot_info_t* bootinfo)
break;
}
#define SECTION(num) ((ELF::SectionHeader32*) ((uintptr_t) elf_sec->addr + (uintptr_t) elf_sec->size * (uintptr_t) (num)))
#define SECTION(num) ((Elf32_Shdr*) ((uintptr_t) elf_sec->addr + (uintptr_t) elf_sec->size * (uintptr_t) (num)))
// Verify the section name section.
ELF::SectionHeader32* section_string_section = SECTION(elf_sec->shndx);
if ( !BELOW_4MIB(section_string_section->addr, section_string_section->size) )
Elf32_Shdr* section_string_section = SECTION(elf_sec->shndx);
if ( !BELOW_4MIB(section_string_section->sh_addr, section_string_section->sh_size) )
{
Log::PrintF("Warning: the section string table was loaded inappropriately by the boot loader, kernel debugging symbols will not be available.\n");
break;
@ -319,39 +319,39 @@ extern "C" void KernelInit(unsigned long magic, multiboot_info_t* bootinfo)
if ( !section_string_section )
break;
const char* section_string_table = (const char*) (uintptr_t) section_string_section->addr;
const char* section_string_table = (const char*) (uintptr_t) section_string_section->sh_addr;
// Find the symbol table.
ELF::SectionHeader32* symbol_table_section = NULL;
Elf32_Shdr* symbol_table_section = NULL;
for ( unsigned i = 0; i < elf_sec->num && !symbol_table_section; i++ )
{
ELF::SectionHeader32* section = SECTION(i);
if ( !strcmp(section_string_table + section->name, ".symtab") )
Elf32_Shdr* section = SECTION(i);
if ( !strcmp(section_string_table + section->sh_name, ".symtab") )
symbol_table_section = section;
}
if ( !symbol_table_section )
break;
if ( !BELOW_4MIB(symbol_table_section->addr, symbol_table_section->size) )
if ( !BELOW_4MIB(symbol_table_section->sh_addr, symbol_table_section->sh_size) )
{
Log::PrintF("Warning: the symbol table was loaded inappropriately by the boot loader, kernel debugging symbols will not be available.\n");
break;
}
// Find the symbol string table.
ELF::SectionHeader32* string_table_section = NULL;
Elf32_Shdr* string_table_section = NULL;
for ( unsigned i = 0; i < elf_sec->num && !string_table_section; i++ )
{
ELF::SectionHeader32* section = SECTION(i);
if ( !strcmp(section_string_table + section->name, ".strtab") )
Elf32_Shdr* section = SECTION(i);
if ( !strcmp(section_string_table + section->sh_name, ".strtab") )
string_table_section = section;
}
if ( !string_table_section )
break;
if ( !BELOW_4MIB(string_table_section->addr, string_table_section->size) )
if ( !BELOW_4MIB(string_table_section->sh_addr, string_table_section->sh_size) )
{
Log::PrintF("Warning: the symbol string table was loaded inappropriately by the boot loader, kernel debugging symbols will not be available.\n");
break;
@ -359,10 +359,10 @@ extern "C" void KernelInit(unsigned long magic, multiboot_info_t* bootinfo)
// Duplicate the data structures and convert them to the kernel symbol
// table format and register it for later debugging.
const char* elf_string_table = (const char*) (uintptr_t) string_table_section->addr;
size_t elf_string_table_size = string_table_section->size;
ELF::Symbol32* elf_symbols = (ELF::Symbol32*) (uintptr_t) symbol_table_section->addr;
size_t elf_symbol_count = symbol_table_section->size / sizeof(ELF::Symbol32);
const char* elf_string_table = (const char*) (uintptr_t) string_table_section->sh_addr;
size_t elf_string_table_size = string_table_section->sh_size;
Elf32_Sym* elf_symbols = (Elf32_Sym*) (uintptr_t) symbol_table_section->sh_addr;
size_t elf_symbol_count = symbol_table_section->sh_size / sizeof(Elf32_Sym);
if ( !elf_symbol_count || elf_symbol_count == 1 /* null symbol */)
break;

5
kernel/process.cpp
View File

@ -49,6 +49,7 @@
#include <sortix/kernel/copy.h>
#include <sortix/kernel/descriptor.h>
#include <sortix/kernel/dtable.h>
#include <sortix/kernel/elf.h>
#include <sortix/kernel/ioctx.h>
#include <sortix/kernel/kernel.h>
#include <sortix/kernel/kthread.h>
@ -66,8 +67,6 @@
#include <sortix/kernel/time.h>
#include <sortix/kernel/worker.h>
#include "elf.h"
#if defined(__i386__) || defined(__x86_64__)
#include "x86-family/float.h"
#include "x86-family/gdt.h"
@ -836,7 +835,7 @@ int Process::Execute(const char* programname, const uint8_t* program,
ELF::Auxiliary aux;
addr_t entry = ELF::Construct(CurrentProcess(), program, programsize, &aux);
addr_t entry = ELF::Load(program, programsize, &aux);
if ( !entry ) { delete[] programname_clone; return -1; }
delete[] program_image_path;

3091
libc/include/elf.h Normal file
View File

File diff suppressed because it is too large Load Diff

94
libc/include/system-elf.h Normal file
View File

@ -0,0 +1,94 @@
/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2014.
This file is part of the Sortix C Library.
The Sortix C Library is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
The Sortix C Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
system-elf.h
Executable and Linkable Format for the local system.
*******************************************************************************/
#ifndef INCLUDE_SYSTEM_ELF_H
#define INCLUDE_SYSTEM_ELF_H
#include <sys/cdefs.h>
#include <elf.h>
#include <__/wordsize.h>
__BEGIN_DECLS
#if __WORDSIZE == 32
typedef Elf32_Half Elf_Half;
typedef Elf32_Word Elf_Word;
typedef Elf32_Sword Elf_Sword;
typedef Elf32_Xword Elf_Xword;
typedef Elf32_Sxword Elf_Sxword;
typedef Elf32_Addr Elf_Addr;
typedef Elf32_Off Elf_Off;
typedef Elf32_Section Elf_Section;
typedef Elf32_Versym Elf_Versym;
typedef Elf32_Ehdr Elf_Ehdr;
typedef Elf32_Shdr Elf_Shdr;
typedef Elf32_Sym Elf_Sym;
typedef Elf32_Syminfo Elf_Syminfo;
typedef Elf32_Rel Elf_Rel;
typedef Elf32_Rela Elf_Rela;
typedef Elf32_Phdr Elf_Phdr;
typedef Elf32_Dyn Elf_Dyn;
typedef Elf32_Verdef Elf_Verdef;
typedef Elf32_Verdaux Elf_Verdaux;
typedef Elf32_Verneed Elf_Verneed;
typedef Elf32_Vernaux Elf_Vernaux;
typedef Elf32_auxv_t Elf_auxv_t;
typedef Elf32_Nhdr Elf_Nhdr;
typedef Elf32_Move Elf_Move;
typedef Elf32_Lib Elf_Lib;
#elif __WORDSIZE == 64
typedef Elf64_Half Elf_Half;
typedef Elf64_Word Elf_Word;
typedef Elf64_Sword Elf_Sword;
typedef Elf64_Xword Elf_Xword;
typedef Elf64_Sxword Elf_Sxword;
typedef Elf64_Addr Elf_Addr;
typedef Elf64_Off Elf_Off;
typedef Elf64_Section Elf_Section;
typedef Elf64_Versym Elf_Versym;
typedef Elf64_Ehdr Elf_Ehdr;
typedef Elf64_Shdr Elf_Shdr;
typedef Elf64_Sym Elf_Sym;
typedef Elf64_Syminfo Elf_Syminfo;
typedef Elf64_Rel Elf_Rel;
typedef Elf64_Rela Elf_Rela;
typedef Elf64_Phdr Elf_Phdr;
typedef Elf64_Dyn Elf_Dyn;
typedef Elf64_Verdef Elf_Verdef;
typedef Elf64_Verdaux Elf_Verdaux;
typedef Elf64_Verneed Elf_Verneed;
typedef Elf64_Vernaux Elf_Vernaux;
typedef Elf64_auxv_t Elf_auxv_t;
typedef Elf64_Nhdr Elf_Nhdr;
typedef Elf64_Move Elf_Move;
typedef Elf64_Lib Elf_Lib;
#else
#error "You need to typedef these to the types of your platform."
#endif
__END_DECLS
#endif

3
libpthread/pthread_initialize.c++
View File

@ -22,6 +22,7 @@
*******************************************************************************/
#include <elf.h>
#include <errno.h>
#include <pthread.h>
#include <signal.h>
@ -31,8 +32,6 @@
#include <string.h>
#include <unistd.h>
#include <sortix/elf-note.h>
extern "C" { pthread_mutex_t __pthread_keys_lock =
PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; }
extern "C" { struct pthread_key* __pthread_keys = NULL; }