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

Rev	Author	Line No.	Line
854	bondari	1	/*
		2	* Copyright (C) 2006 Sergey Bondari
1424	jermar	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
910	bondari	39	#include <elf.h>
938	jermar	40	#include <debug.h>
		41	#include <arch/types.h>
		42	#include <typedefs.h>
		43	#include <mm/as.h>
		44	#include <mm/frame.h>
952	jermar	45	#include <mm/slab.h>
938	jermar	46	#include <align.h>
952	jermar	47	#include <memstr.h>
		48	#include <macros.h>
1409	jermar	49	#include <arch.h>
854	bondari	50
938	jermar	51	static char *error_codes[] = {
		52	"no error",
		53	"invalid image",
		54	"address space error",
		55	"incompatible image",
		56	"unsupported image type",
		57	"irrecoverable error"
		58	};
		59
952	jermar	60	static int segment_header(elf_segment_header_t entry, elf_header_t elf, as_t *as);
		61	static int section_header(elf_section_header_t entry, elf_header_t elf, as_t *as);
		62	static int load_segment(elf_segment_header_t entry, elf_header_t elf, as_t *as);
938	jermar	63
		64	/** ELF loader
854	bondari	65	*
		66	* @param header Pointer to ELF header in memory
		67	* @param as Created and properly mapped address space
		68	* @return EE_OK on success
		69	*/
938	jermar	70	int elf_load(elf_header_t header, as_t as)
		71	{
		72	int i, rc;
910	bondari	73
		74	/* Identify ELF */
938	jermar	75	if (header->e_ident[EI_MAG0] != ELFMAG0 \|\| header->e_ident[EI_MAG1] != ELFMAG1 \|\|
		76	header->e_ident[EI_MAG2] != ELFMAG2 \|\| header->e_ident[EI_MAG3] != ELFMAG3) {
910	bondari	77	return EE_INVALID;
		78	}
		79
		80	/* Identify ELF compatibility */
938	jermar	81	if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING \|\| header->e_machine != ELF_MACHINE \|\|
		82	header->e_ident[EI_VERSION] != EV_CURRENT \|\| header->e_version != EV_CURRENT \|\|
		83	header->e_ident[EI_CLASS] != ELF_CLASS) {
		84	return EE_INCOMPATIBLE;
		85	}
		86
952	jermar	87	if (header->e_phentsize != sizeof(elf_segment_header_t))
938	jermar	88	return EE_INCOMPATIBLE;
		89
952	jermar	90	if (header->e_shentsize != sizeof(elf_section_header_t))
		91	return EE_INCOMPATIBLE;
		92
938	jermar	93	/* Check if the object type is supported. */
		94	if (header->e_type != ET_EXEC)
910	bondari	95	return EE_UNSUPPORTED;
938	jermar	96
952	jermar	97	/* Walk through all segment headers and process them. */
938	jermar	98	for (i = 0; i < header->e_phnum; i++) {
952	jermar	99	rc = segment_header(&((elf_segment_header_t )(((__u8 ) header) + header->e_phoff))[i], header, as);
938	jermar	100	if (rc != EE_OK)
		101	return rc;
910	bondari	102	}
938	jermar	103
952	jermar	104	/* Inspect all section headers and proccess them. */
		105	for (i = 0; i < header->e_shnum; i++) {
		106	rc = section_header(&((elf_section_header_t )(((__u8 ) header) + header->e_shoff))[i], header, as);
		107	if (rc != EE_OK)
		108	return rc;
		109	}
		110
938	jermar	111	return EE_OK;
		112	}
		113
		114	/** Print error message according to error code.
		115	*
		116	* @param rc Return code returned by elf_load().
		117	*
		118	* @return NULL terminated description of error.
		119	*/
		120	char *elf_error(int rc)
		121	{
		122	ASSERT(rc < sizeof(error_codes)/sizeof(char *));
		123
		124	return error_codes[rc];
		125	}
		126
952	jermar	127	/** Process segment header.
938	jermar	128	*
952	jermar	129	* @param entry Segment header.
		130	* @param elf ELF header.
938	jermar	131	* @param as Address space into wich the ELF is being loaded.
		132	*
		133	* @return EE_OK on success, error code otherwise.
		134	*/
952	jermar	135	static int segment_header(elf_segment_header_t entry, elf_header_t elf, as_t *as)
938	jermar	136	{
		137	switch (entry->p_type) {
		138	case PT_NULL:
		139	case PT_PHDR:
		140	break;
		141	case PT_LOAD:
952	jermar	142	return load_segment(entry, elf, as);
938	jermar	143	break;
		144	case PT_DYNAMIC:
		145	case PT_INTERP:
		146	case PT_SHLIB:
		147	case PT_NOTE:
		148	case PT_LOPROC:
		149	case PT_HIPROC:
		150	default:
		151	return EE_UNSUPPORTED;
		152	break;
		153	}
		154	return EE_OK;
		155	}
		156
		157	/** Load segment described by program header entry.
		158	*
		159	* @param entry Program header entry describing segment to be loaded.
952	jermar	160	* @param elf ELF header.
1248	jermar	161	* @param as Address space into wich the ELF is being loaded.
938	jermar	162	*
		163	* @return EE_OK on success, error code otherwise.
		164	*/
952	jermar	165	int load_segment(elf_segment_header_t entry, elf_header_t elf, as_t *as)
938	jermar	166	{
		167	as_area_t *a;
1409	jermar	168	int flags = 0;
1425	jermar	169	mem_backend_data_t backend_data;
		170
		171	backend_data.elf = elf;
		172	backend_data.segment = entry;
938	jermar	173
		174	if (entry->p_align > 1) {
		175	if ((entry->p_offset % entry->p_align) != (entry->p_vaddr % entry->p_align)) {
		176	return EE_INVALID;
		177	}
		178	}
		179
1026	jermar	180	if (entry->p_flags & PF_X)
		181	flags \|= AS_AREA_EXEC;
		182	if (entry->p_flags & PF_W)
		183	flags \|= AS_AREA_WRITE;
		184	if (entry->p_flags & PF_R)
		185	flags \|= AS_AREA_READ;
1424	jermar	186	flags \|= AS_AREA_CACHEABLE;
910	bondari	187
952	jermar	188	/*
		189	* Check if the virtual address starts on page boundary.
		190	*/
		191	if (ALIGN_UP(entry->p_vaddr, PAGE_SIZE) != entry->p_vaddr)
		192	return EE_UNSUPPORTED;
		193
1424	jermar	194	a = as_area_create(as, flags, entry->p_memsz, entry->p_vaddr, AS_AREA_ATTR_NONE,
		195	&elf_backend, &backend_data);
938	jermar	196	if (!a)
1070	jermar	197	return EE_MEMORY;
938	jermar	198
1409	jermar	199	/*
		200	* The segment will be mapped on demand by elf_page_fault().
		201	*/
		202
938	jermar	203	return EE_OK;
854	bondari	204	}
952	jermar	205
		206	/** Process section header.
		207	*
		208	* @param entry Segment header.
		209	* @param elf ELF header.
		210	* @param as Address space into wich the ELF is being loaded.
		211	*
		212	* @return EE_OK on success, error code otherwise.
		213	*/
		214	static int section_header(elf_section_header_t entry, elf_header_t elf, as_t *as)
		215	{
		216	switch (entry->sh_type) {
		217	default:
		218	break;
		219	}
		220
		221	return EE_OK;
		222	}
1702	cejka	223
1757	jermar	224	/** @}
1702	cejka	225	*/

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(root)/kernel/trunk/generic/src/lib/elf.c – Rev 1757