WebSVN – HelenOS – Blame – /trunk/kernel/generic/src/lib/elf.c

Rev	Author	Line No.	Line
854	bondari	1	/*
2071	jermar	2	* Copyright (c) 2006 Sergey Bondari
		3	* Copyright (c) 2006 Jakub Jermar
854	bondari	4	* All rights reserved.
		5	*
		6	* Redistribution and use in source and binary forms, with or without
		7	* modification, are permitted provided that the following conditions
		8	* are met:
		9	*
		10	* - Redistributions of source code must retain the above copyright
		11	* notice, this list of conditions and the following disclaimer.
		12	* - Redistributions in binary form must reproduce the above copyright
		13	* notice, this list of conditions and the following disclaimer in the
		14	* documentation and/or other materials provided with the distribution.
		15	* - The name of the author may not be used to endorse or promote products
		16	* derived from this software without specific prior written permission.
		17	*
		18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
		19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
		20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
		21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
		22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
		23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
		24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
		25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
		26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
		27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
		28	*/
		29
1757	jermar	30	/** @addtogroup generic
1702	cejka	31	* @{
		32	*/
		33
1264	jermar	34	/**
1702	cejka	35	* @file
1264	jermar	36	* @brief Kernel ELF loader.
		37	*/
		38
2000	decky	39	#include <lib/elf.h>
938	jermar	40	#include <debug.h>
		41	#include <arch/types.h>
		42	#include <mm/as.h>
		43	#include <mm/frame.h>
952	jermar	44	#include <mm/slab.h>
938	jermar	45	#include <align.h>
952	jermar	46	#include <memstr.h>
		47	#include <macros.h>
1409	jermar	48	#include <arch.h>
854	bondari	49
938	jermar	50	static char *error_codes[] = {
		51	"no error",
		52	"invalid image",
		53	"address space error",
		54	"incompatible image",
		55	"unsupported image type",
		56	"irrecoverable error"
		57	};
		58
952	jermar	59	static int segment_header(elf_segment_header_t entry, elf_header_t elf, as_t *as);
		60	static int section_header(elf_section_header_t entry, elf_header_t elf, as_t *as);
		61	static int load_segment(elf_segment_header_t entry, elf_header_t elf, as_t *as);
938	jermar	62
		63	/** ELF loader
854	bondari	64	*
		65	* @param header Pointer to ELF header in memory
		66	* @param as Created and properly mapped address space
		67	* @return EE_OK on success
		68	*/
938	jermar	69	int elf_load(elf_header_t header, as_t as)
		70	{
		71	int i, rc;
910	bondari	72
		73	/* Identify ELF */
938	jermar	74	if (header->e_ident[EI_MAG0] != ELFMAG0 \|\| header->e_ident[EI_MAG1] != ELFMAG1 \|\|
		75	header->e_ident[EI_MAG2] != ELFMAG2 \|\| header->e_ident[EI_MAG3] != ELFMAG3) {
910	bondari	76	return EE_INVALID;
		77	}
		78
		79	/* Identify ELF compatibility */
938	jermar	80	if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING \|\| header->e_machine != ELF_MACHINE \|\|
		81	header->e_ident[EI_VERSION] != EV_CURRENT \|\| header->e_version != EV_CURRENT \|\|
		82	header->e_ident[EI_CLASS] != ELF_CLASS) {
		83	return EE_INCOMPATIBLE;
		84	}
		85
952	jermar	86	if (header->e_phentsize != sizeof(elf_segment_header_t))
938	jermar	87	return EE_INCOMPATIBLE;
		88
952	jermar	89	if (header->e_shentsize != sizeof(elf_section_header_t))
		90	return EE_INCOMPATIBLE;
		91
938	jermar	92	/* Check if the object type is supported. */
		93	if (header->e_type != ET_EXEC)
910	bondari	94	return EE_UNSUPPORTED;
938	jermar	95
952	jermar	96	/* Walk through all segment headers and process them. */
938	jermar	97	for (i = 0; i < header->e_phnum; i++) {
1780	jermar	98	rc = segment_header(&((elf_segment_header_t )(((uint8_t ) header) + header->e_phoff))[i], header, as);
938	jermar	99	if (rc != EE_OK)
		100	return rc;
910	bondari	101	}
938	jermar	102
952	jermar	103	/* Inspect all section headers and proccess them. */
		104	for (i = 0; i < header->e_shnum; i++) {
1780	jermar	105	rc = section_header(&((elf_section_header_t )(((uint8_t ) header) + header->e_shoff))[i], header, as);
952	jermar	106	if (rc != EE_OK)
		107	return rc;
		108	}
		109
938	jermar	110	return EE_OK;
		111	}
		112
		113	/** Print error message according to error code.
		114	*
		115	* @param rc Return code returned by elf_load().
		116	*
		117	* @return NULL terminated description of error.
		118	*/
		119	char *elf_error(int rc)
		120	{
		121	ASSERT(rc < sizeof(error_codes)/sizeof(char *));
		122
		123	return error_codes[rc];
		124	}
		125
952	jermar	126	/** Process segment header.
938	jermar	127	*
952	jermar	128	* @param entry Segment header.
		129	* @param elf ELF header.
938	jermar	130	* @param as Address space into wich the ELF is being loaded.
		131	*
		132	* @return EE_OK on success, error code otherwise.
		133	*/
952	jermar	134	static int segment_header(elf_segment_header_t entry, elf_header_t elf, as_t *as)
938	jermar	135	{
		136	switch (entry->p_type) {
2062	jermar	137	case PT_NULL:
		138	case PT_PHDR:
938	jermar	139	break;
2062	jermar	140	case PT_LOAD:
952	jermar	141	return load_segment(entry, elf, as);
938	jermar	142	break;
2062	jermar	143	case PT_DYNAMIC:
		144	case PT_INTERP:
		145	case PT_SHLIB:
		146	case PT_NOTE:
		147	case PT_LOPROC:
		148	case PT_HIPROC:
		149	default:
938	jermar	150	return EE_UNSUPPORTED;
		151	break;
		152	}
		153	return EE_OK;
		154	}
		155
		156	/** Load segment described by program header entry.
		157	*
		158	* @param entry Program header entry describing segment to be loaded.
952	jermar	159	* @param elf ELF header.
1248	jermar	160	* @param as Address space into wich the ELF is being loaded.
938	jermar	161	*
		162	* @return EE_OK on success, error code otherwise.
		163	*/
952	jermar	164	int load_segment(elf_segment_header_t entry, elf_header_t elf, as_t *as)
938	jermar	165	{
		166	as_area_t *a;
1409	jermar	167	int flags = 0;
1425	jermar	168	mem_backend_data_t backend_data;
		169
		170	backend_data.elf = elf;
		171	backend_data.segment = entry;
938	jermar	172
		173	if (entry->p_align > 1) {
		174	if ((entry->p_offset % entry->p_align) != (entry->p_vaddr % entry->p_align)) {
		175	return EE_INVALID;
		176	}
		177	}
		178
1026	jermar	179	if (entry->p_flags & PF_X)
		180	flags \|= AS_AREA_EXEC;
		181	if (entry->p_flags & PF_W)
		182	flags \|= AS_AREA_WRITE;
		183	if (entry->p_flags & PF_R)
		184	flags \|= AS_AREA_READ;
1424	jermar	185	flags \|= AS_AREA_CACHEABLE;
910	bondari	186
952	jermar	187	/*
		188	* Check if the virtual address starts on page boundary.
		189	*/
		190	if (ALIGN_UP(entry->p_vaddr, PAGE_SIZE) != entry->p_vaddr)
		191	return EE_UNSUPPORTED;
		192
1424	jermar	193	a = as_area_create(as, flags, entry->p_memsz, entry->p_vaddr, AS_AREA_ATTR_NONE,
		194	&elf_backend, &backend_data);
938	jermar	195	if (!a)
1070	jermar	196	return EE_MEMORY;
938	jermar	197
1409	jermar	198	/*
		199	* The segment will be mapped on demand by elf_page_fault().
		200	*/
		201
938	jermar	202	return EE_OK;
854	bondari	203	}
952	jermar	204
		205	/** Process section header.
		206	*
		207	* @param entry Segment header.
		208	* @param elf ELF header.
		209	* @param as Address space into wich the ELF is being loaded.
		210	*
		211	* @return EE_OK on success, error code otherwise.
		212	*/
		213	static int section_header(elf_section_header_t entry, elf_header_t elf, as_t *as)
		214	{
		215	switch (entry->sh_type) {
2062	jermar	216	default:
952	jermar	217	break;
		218	}
		219
		220	return EE_OK;
		221	}
1702	cejka	222
1757	jermar	223	/** @}
1702	cejka	224	*/

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/lib/elf.c – Rev 2089