0,0 → 1,224 |
/* |
* Copyright (c) 2006 Sergey Bondari |
* Copyright (c) 2006 Jakub Jermar |
* All rights reserved. |
* |
* Redistribution and use in source and binary forms, with or without |
* modification, are permitted provided that the following conditions |
* are met: |
* |
* - Redistributions of source code must retain the above copyright |
* notice, this list of conditions and the following disclaimer. |
* - Redistributions in binary form must reproduce the above copyright |
* notice, this list of conditions and the following disclaimer in the |
* documentation and/or other materials provided with the distribution. |
* - The name of the author may not be used to endorse or promote products |
* derived from this software without specific prior written permission. |
* |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
*/ |
|
/** @addtogroup generic |
* @{ |
*/ |
|
/** |
* @file |
* @brief Kernel ELF loader. |
*/ |
|
#include <lib/elf.h> |
#include <debug.h> |
#include <arch/types.h> |
#include <mm/as.h> |
#include <mm/frame.h> |
#include <mm/slab.h> |
#include <align.h> |
#include <memstr.h> |
#include <macros.h> |
#include <arch.h> |
|
static char *error_codes[] = { |
"no error", |
"invalid image", |
"address space error", |
"incompatible image", |
"unsupported image type", |
"irrecoverable error" |
}; |
|
static int segment_header(elf_segment_header_t *entry, elf_header_t *elf, as_t *as); |
static int section_header(elf_section_header_t *entry, elf_header_t *elf, as_t *as); |
static int load_segment(elf_segment_header_t *entry, elf_header_t *elf, as_t *as); |
|
/** ELF loader |
* |
* @param header Pointer to ELF header in memory |
* @param as Created and properly mapped address space |
* @return EE_OK on success |
*/ |
int elf_load(elf_header_t *header, as_t * as) |
{ |
int i, rc; |
|
/* Identify ELF */ |
if (header->e_ident[EI_MAG0] != ELFMAG0 || header->e_ident[EI_MAG1] != ELFMAG1 || |
header->e_ident[EI_MAG2] != ELFMAG2 || header->e_ident[EI_MAG3] != ELFMAG3) { |
return EE_INVALID; |
} |
|
/* Identify ELF compatibility */ |
if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING || header->e_machine != ELF_MACHINE || |
header->e_ident[EI_VERSION] != EV_CURRENT || header->e_version != EV_CURRENT || |
header->e_ident[EI_CLASS] != ELF_CLASS) { |
return EE_INCOMPATIBLE; |
} |
|
if (header->e_phentsize != sizeof(elf_segment_header_t)) |
return EE_INCOMPATIBLE; |
|
if (header->e_shentsize != sizeof(elf_section_header_t)) |
return EE_INCOMPATIBLE; |
|
/* Check if the object type is supported. */ |
if (header->e_type != ET_EXEC) |
return EE_UNSUPPORTED; |
|
/* Walk through all segment headers and process them. */ |
for (i = 0; i < header->e_phnum; i++) { |
rc = segment_header(&((elf_segment_header_t *)(((uint8_t *) header) + header->e_phoff))[i], header, as); |
if (rc != EE_OK) |
return rc; |
} |
|
/* Inspect all section headers and proccess them. */ |
for (i = 0; i < header->e_shnum; i++) { |
rc = section_header(&((elf_section_header_t *)(((uint8_t *) header) + header->e_shoff))[i], header, as); |
if (rc != EE_OK) |
return rc; |
} |
|
return EE_OK; |
} |
|
/** Print error message according to error code. |
* |
* @param rc Return code returned by elf_load(). |
* |
* @return NULL terminated description of error. |
*/ |
char *elf_error(int rc) |
{ |
ASSERT(rc < sizeof(error_codes)/sizeof(char *)); |
|
return error_codes[rc]; |
} |
|
/** Process segment header. |
* |
* @param entry Segment header. |
* @param elf ELF header. |
* @param as Address space into wich the ELF is being loaded. |
* |
* @return EE_OK on success, error code otherwise. |
*/ |
static int segment_header(elf_segment_header_t *entry, elf_header_t *elf, as_t *as) |
{ |
switch (entry->p_type) { |
case PT_NULL: |
case PT_PHDR: |
break; |
case PT_LOAD: |
return load_segment(entry, elf, as); |
break; |
case PT_DYNAMIC: |
case PT_INTERP: |
case PT_SHLIB: |
case PT_NOTE: |
case PT_LOPROC: |
case PT_HIPROC: |
default: |
return EE_UNSUPPORTED; |
break; |
} |
return EE_OK; |
} |
|
/** Load segment described by program header entry. |
* |
* @param entry Program header entry describing segment to be loaded. |
* @param elf ELF header. |
* @param as Address space into wich the ELF is being loaded. |
* |
* @return EE_OK on success, error code otherwise. |
*/ |
int load_segment(elf_segment_header_t *entry, elf_header_t *elf, as_t *as) |
{ |
as_area_t *a; |
int flags = 0; |
mem_backend_data_t backend_data; |
|
backend_data.elf = elf; |
backend_data.segment = entry; |
|
if (entry->p_align > 1) { |
if ((entry->p_offset % entry->p_align) != (entry->p_vaddr % entry->p_align)) { |
return EE_INVALID; |
} |
} |
|
if (entry->p_flags & PF_X) |
flags |= AS_AREA_EXEC; |
if (entry->p_flags & PF_W) |
flags |= AS_AREA_WRITE; |
if (entry->p_flags & PF_R) |
flags |= AS_AREA_READ; |
flags |= AS_AREA_CACHEABLE; |
|
/* |
* Check if the virtual address starts on page boundary. |
*/ |
if (ALIGN_UP(entry->p_vaddr, PAGE_SIZE) != entry->p_vaddr) |
return EE_UNSUPPORTED; |
|
a = as_area_create(as, flags, entry->p_memsz, entry->p_vaddr, AS_AREA_ATTR_NONE, |
&elf_backend, &backend_data); |
if (!a) |
return EE_MEMORY; |
|
/* |
* The segment will be mapped on demand by elf_page_fault(). |
*/ |
|
return EE_OK; |
} |
|
/** Process section header. |
* |
* @param entry Segment header. |
* @param elf ELF header. |
* @param as Address space into wich the ELF is being loaded. |
* |
* @return EE_OK on success, error code otherwise. |
*/ |
static int section_header(elf_section_header_t *entry, elf_header_t *elf, as_t *as) |
{ |
switch (entry->sh_type) { |
default: |
break; |
} |
|
return EE_OK; |
} |
|
/** @} |
*/ |