sortix-mirror/kernel/elf.cpp
Jonas 'Sortie' Termansen 2b72262b4f Relicense Sortix to the ISC license.
I hereby relicense all my work on Sortix under the ISC license as below.

All Sortix contributions by other people are already under this license,
are not substantial enough to be copyrightable, or have been removed.

All imported code from other projects is compatible with this license.

All GPL licensed code from other projects had previously been removed.

Copyright 2011-2016 Jonas 'Sortie' Termansen and contributors.

Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
2016-03-05 22:21:50 +01:00

325 lines
9.5 KiB
C++

/*
* Copyright (c) 2011, 2012, 2013, 2014 Jonas 'Sortie' Termansen.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* elf.cpp
* 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/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>
namespace Sortix {
namespace ELF {
static bool is_power_of_two(uintptr_t value)
{
for ( uintptr_t i = 0; i < sizeof(uintptr_t) * 8; i++ )
if ( (uintptr_t) 1 << i == value )
return true;
return false;
}
uintptr_t Load(const void* file_ptr, size_t file_size, Auxiliary* aux)
{
memset(aux, 0, sizeof(*aux));
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++ )
{
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;
(void) available;
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_memsz < pheader->p_filesz )
return errno = EINVAL, 0;
if ( pheader->p_filesz &&
pheader->p_vaddr % pheader->p_align !=
pheader->p_offset % pheader->p_align )
return errno = EINVAL, 0;
int kprot = PROT_KWRITE | PROT_FORK;
int prot = PROT_FORK;
if ( pheader->p_flags & PF_X )
prot |= PROT_EXEC;
if ( pheader->p_flags & PF_R )
prot |= PROT_READ | PROT_KREAD;
if ( pheader->p_flags & PF_W )
prot |= PROT_WRITE | PROT_KWRITE;
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 = kprot;
assert(IsUserspaceSegment(&segment));
kthread_mutex_lock(&process->segment_write_lock);
kthread_mutex_lock(&process->segment_lock);
if ( IsSegmentOverlapping(process, &segment) )
{
kthread_mutex_unlock(&process->segment_lock);
kthread_mutex_unlock(&process->segment_write_lock);
return errno = EINVAL, 0;
}
if ( !Memory::MapRange(segment.addr, segment.size, kprot, PAGE_USAGE_USER_SPACE) )
{
kthread_mutex_unlock(&process->segment_lock);
kthread_mutex_unlock(&process->segment_write_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);
kthread_mutex_unlock(&process->segment_write_lock);
return errno = EINVAL, 0;
}
memset((void*) segment.addr, 0, segment.size);
memcpy((void*) pheader->p_vaddr, file + pheader->p_offset, pheader->p_filesz);
Memory::ProtectMemory(CurrentProcess(), segment.addr, segment.size, prot);
kthread_mutex_unlock(&process->segment_lock);
kthread_mutex_unlock(&process->segment_write_lock);
}
}
return header->e_entry;
}
} // namespace ELF
} // namespace Sortix