WebSVN – HelenOS – Diff – /branches/dynload/uspace/srv/loader/elf_load.c


/*
 * Copyright (c) 2006 Sergey Bondari
 * Copyright (c) 2006 Jakub Jermar
 * Copyright (c) 2008 Jiri Svoboda
 * 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   Userspace ELF loader.
 *
 * This module allows loading ELF binaries (both executables and
 * shared objects) from VFS. The current implementation allocates
 * anonymous memory, fills it with segment data and then adjusts
 * the memory areas' flags to the final value. In the future,
 * the segments will be mapped directly from the file.
 */
 
#include <stdio.h>
#include <sys/types.h>
#include <align.h>
#include <assert.h>
#include <as.h>
#include <unistd.h>
#include <fcntl.h>
 
#include "elf.h"
#include "pcb.h"
#include "elf_load.h"
#include "arch.h"
 
static char *error_codes[] = {
    "no error",
    "invalid image",
    "address space error",
    "incompatible image",
    "unsupported image type",
    "irrecoverable error"
};
 
static unsigned int elf_load(elf_ld_t *elf, size_t so_bias);
static int segment_header(elf_ld_t *elf, elf_segment_header_t *entry);
static int section_header(elf_ld_t *elf, elf_section_header_t *entry);
static int load_segment(elf_ld_t *elf, elf_segment_header_t *entry);
 
/** Load ELF binary from a file.
 *
 * Load an ELF binary from the specified file. If the file is
 * an executable program, it is loaded unbiased. If it is a shared
 * object, it is loaded with the bias @a so_bias. Some information
 * extracted from the binary is stored in a elf_info_t structure
 * pointed to by @a info.
 *
 * @param file_name Path to the ELF file.
 * @param so_bias   Bias to use if the file is a shared object.
 * @param info      Pointer to a structure for storing information
 *          extracted from the binary.
 *
 * @return EOK on success or negative error code.
 */
int elf_load_file(char *file_name, size_t so_bias, elf_info_t *info)
{
    elf_ld_t elf;
 
    int fd;
    int rc;
 
//  printf("open and read '%s'...\n", file_name);
 
    fd = open(file_name, O_RDONLY);
    if (fd < 0) {
        printf("failed opening file\n");
        return -1;
    }
 
    elf.fd = fd;
    elf.info = info;
 
    rc = elf_load(&elf, so_bias);
 
    close(fd);
 
    return rc;
}
 
/** Run an ELF executable.
 *
 * Transfers control to the entry point of an ELF executable loaded
 * earlier with elf_load_file(). This function does not return.
 *
 * @param info  Info structure filled earlier by elf_load_file()
 */
void elf_run(elf_info_t *info)
{
    program_run(info->entry);
 
    /* not reached */
}
 
/** Create the program control block (PCB).
 *
 * Create and install the program control block, initialising it
 * with program information from @a info.
 *
 * @param info  Program info structure
 * @return EOK on success or negative error code
 */
int elf_create_pcb(elf_info_t *info)
{
    pcb_t *pcb;
    void *a;
 
    pcb = __pcb_get();
 
    a = as_area_create(pcb, sizeof(pcb_t), AS_AREA_READ | AS_AREA_WRITE);
    if (a == (void *)(-1)) {
        printf("elf_create_pcb: memory mapping failed\n");
        return EE_MEMORY;
    }
 
    pcb->entry = info->entry;
    pcb->dynamic = info->dynamic;
 
    return 0;
}
 
 
/** Load an ELF binary.
 *
 * The @a elf structure contains the loader state, including
 * an open file, from which the binary will be loaded,
 * a pointer to the @c info structure etc.
 *
 * @param elf       Pointer to loader state buffer.
 * @param so_bias   Bias to use if the file is a shared object.
 * @return EE_OK on success or EE_xx error code.
 */
static unsigned int elf_load(elf_ld_t *elf, size_t so_bias)
{
    elf_header_t header_buf;
    elf_header_t *header = &header_buf;
    int i, rc;
 
    rc = read(elf->fd, header, sizeof(elf_header_t));
    if (rc < 0) {
        printf("read error\n");
        return EE_INVALID;
    }
 
    elf->header = header;
 
//  printf("ELF-load:");
    /* 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) {
        printf("invalid header\n");
        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) {
        printf("incompatible data/version/class\n");
        return EE_INCOMPATIBLE;
    }
 
    if (header->e_phentsize != sizeof(elf_segment_header_t)) {
        printf("e_phentsize:%d != %d\n", header->e_phentsize,
            sizeof(elf_segment_header_t));
        return EE_INCOMPATIBLE;
    }
 
    if (header->e_shentsize != sizeof(elf_section_header_t)) {
        printf("e_shentsize:%d != %d\n", header->e_shentsize,
            sizeof(elf_section_header_t));
        return EE_INCOMPATIBLE;
    }
 
    /* Check if the object type is supported. */
    if (header->e_type != ET_EXEC && header->e_type != ET_DYN) {
        printf("Object type %d is not supported\n", header->e_type);
        return EE_UNSUPPORTED;
    }
 
    /* Shared objects can be loaded with a bias */
//  printf("Object type: %d\n", header->e_type);
    if (header->e_type == ET_DYN)
        elf->bias = so_bias;
    else
        elf->bias = 0;
 
//  printf("Bias set to 0x%x\n", elf->bias);
    elf->info->interp = NULL;
    elf->info->dynamic = NULL;
 
//  printf("parse segments\n");
 
    /* Walk through all segment headers and process them. */
    for (i = 0; i < header->e_phnum; i++) {
        elf_segment_header_t segment_hdr;
 
        /* Seek to start of segment header */
        lseek(elf->fd, header->e_phoff
                + i * sizeof(elf_segment_header_t), SEEK_SET);
 
        rc = read(elf->fd, &segment_hdr, sizeof(elf_segment_header_t));
        if (rc < 0) { printf("read error\n"); return EE_INVALID; }
 
        rc = segment_header(elf, &segment_hdr);
        if (rc != EE_OK)
            return rc;
    }
 
//  printf("parse sections\n");
 
    /* Inspect all section headers and proccess them. */
    for (i = 0; i < header->e_shnum; i++) {
        elf_section_header_t section_hdr;
 
        /* Seek to start of section header */
        lseek(elf->fd, header->e_shoff
            + i * sizeof(elf_section_header_t), SEEK_SET);
 
        rc = read(elf->fd, &section_hdr, sizeof(elf_section_header_t));
        if (rc < 0) { printf("read error\n"); return EE_INVALID; }
 
        rc = section_header(elf, &section_hdr);
        if (rc != EE_OK)
            return rc;
    }
 
    elf->info->entry =
        (entry_point_t)((uint8_t *)header->e_entry + elf->bias);
 
//  printf("done\n");
 
    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(unsigned int rc)
{
    assert(rc < sizeof(error_codes) / sizeof(char *));
 
    return error_codes[rc];
}
 
/** Process segment header.
 *
 * @param entry Segment header.
 *
 * @return EE_OK on success, error code otherwise.
 */
static int segment_header(elf_ld_t *elf, elf_segment_header_t *entry)
{
    switch (entry->p_type) {
    case PT_NULL:
    case PT_PHDR:
        break;
    case PT_LOAD:
        return load_segment(elf, entry);
        break;
    case PT_INTERP:
        /* Assume silently interp == "/rtld.so" */
        elf->info->interp = "/rtld.so";
        break;
    case PT_DYNAMIC:
    case PT_SHLIB:
    case PT_NOTE:
    case PT_LOPROC:
    case PT_HIPROC:
    default:
        printf("segment p_type %d unknown\n", entry->p_type);
        return EE_UNSUPPORTED;
        break;
    }
    return EE_OK;
}
 
/** Load segment described by program header entry.
 *
 * @param elf   Loader state.
 * @param entry Program header entry describing segment to be loaded.
 *
 * @return EE_OK on success, error code otherwise.
 */
int load_segment(elf_ld_t *elf, elf_segment_header_t *entry)
{
    void *a;
    int flags = 0;
    uintptr_t bias;
    uintptr_t base;
    size_t mem_sz;
    int rc;
 
//  printf("load segment at addr 0x%x, size 0x%x\n", entry->p_vaddr,
//      entry->p_memsz);
   
    bias = elf->bias;
 
    if (entry->p_align > 1) {
        if ((entry->p_offset % entry->p_align) !=
            (entry->p_vaddr % entry->p_align)) {
            printf("align check 1 failed offset%%align=%d, vaddr%%align=%d\n",
            entry->p_offset % entry->p_align,
            entry->p_vaddr % entry->p_align
            );
            return EE_INVALID;
        }
    }
 
    /* Final flags that will be set for the memory area */
 
    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;
   
    base = ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE);
    mem_sz = entry->p_memsz + (entry->p_vaddr - base);
 
//  printf("map to p_vaddr=0x%x-0x%x...\n", entry->p_vaddr + bias,
//  entry->p_vaddr + bias + ALIGN_UP(entry->p_memsz, PAGE_SIZE));
 
    /*
     * For the course of loading, the area needs to be readable
     * and writeable.
     */
    a = as_area_create((uint8_t *)base + bias,
        mem_sz, AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE);
    if (a == (void *)(-1)) {
        printf("memory mapping failed\n");
        return EE_MEMORY;
    }
 
//  printf("as_area_create(0x%lx, 0x%x, %d) -> 0x%lx\n",
//      entry->p_vaddr+bias, entry->p_memsz, flags, (uintptr_t)a);
 
    /*
     * Load segment data
     */
//  printf("seek to %d\n", entry->p_offset);
    rc = lseek(elf->fd, entry->p_offset, SEEK_SET);
    if (rc < 0) { printf("seek error\n"); return EE_INVALID; }
 
//  printf("read 0x%x bytes to address 0x%x\n", entry->p_filesz, entry->p_vaddr+bias);
/*  rc = read(fd, (void *)(entry->p_vaddr + bias), entry->p_filesz);
    if (rc < 0) { printf("read error\n"); return EE_INVALID; }*/
 
    /* Long reads are not possible yet. Load segment picewise */
 
    unsigned left, now;
    uint8_t *dp;
 
    left = entry->p_filesz;
    dp = (uint8_t *)(entry->p_vaddr + bias);
 
    while (left > 0) {
        now = 16384;
        if (now > left) now = left;
 
//      printf("read %d...", now);
        rc = read(elf->fd, dp, now);
//      printf("->%d\n", rc);
 
        if (rc < 0) { printf("read error\n"); return EE_INVALID; }
 
        left -= now;
        dp += now;
    }
 
//  printf("set area flags to %d\n", flags);
    rc = as_area_change_flags((uint8_t *)entry->p_vaddr + bias, flags);
    if (rc != 0) {
        printf("failed to set memory area flags\n");
        return EE_MEMORY;
    }
 
    return EE_OK;
}
 
/** Process section header.
 *
 * @param elf   Loader state.
 * @param entry Segment header.
 *
 * @return EE_OK on success, error code otherwise.
 */
static int section_header(elf_ld_t *elf, elf_section_header_t *entry)
{
    switch (entry->sh_type) {
    case SHT_PROGBITS:
        if (entry->sh_flags & SHF_TLS) {
            /* .tdata */
        }
        break;
    case SHT_NOBITS:
        if (entry->sh_flags & SHF_TLS) {
            /* .tbss */
        }
        break;
    case SHT_DYNAMIC:
        /* Record pointer to dynamic section into info structure */
        elf->info->dynamic =
            (void *)((uint8_t *)entry->sh_addr + elf->bias);
        printf("dynamic section found at 0x%x\n",
            (uintptr_t)elf->info->dynamic);
        break;
    default:
        break;
    }
   
    return EE_OK;
}
 
/** @}
 */
 

Rev 3155	Rev 3157
1	/*	1	/*
2	* Copyright (c) 2006 Sergey Bondari	2	* Copyright (c) 2006 Sergey Bondari
3	* Copyright (c) 2006 Jakub Jermar	3	* Copyright (c) 2006 Jakub Jermar
4	* Copyright (c) 2008 Jiri Svoboda	4	* Copyright (c) 2008 Jiri Svoboda
5	* All rights reserved.	5	* All rights reserved.
6	*	6	*
7	* Redistribution and use in source and binary forms, with or without	7	* Redistribution and use in source and binary forms, with or without
8	* modification, are permitted provided that the following conditions	8	* modification, are permitted provided that the following conditions
9	* are met:	9	* are met:
10	*	10	*
11	* - Redistributions of source code must retain the above copyright	11	* - Redistributions of source code must retain the above copyright
12	* notice, this list of conditions and the following disclaimer.	12	* notice, this list of conditions and the following disclaimer.
13	* - Redistributions in binary form must reproduce the above copyright	13	* - Redistributions in binary form must reproduce the above copyright
14	* notice, this list of conditions and the following disclaimer in the	14	* notice, this list of conditions and the following disclaimer in the
15	* documentation and/or other materials provided with the distribution.	15	* documentation and/or other materials provided with the distribution.
16	* - The name of the author may not be used to endorse or promote products	16	* - The name of the author may not be used to endorse or promote products
17	* derived from this software without specific prior written permission.	17	* derived from this software without specific prior written permission.
18	*	18	*
19	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	19	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	20	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	21	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	22	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	23	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	24	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	25	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	26	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	27	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	28	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29	*/	29	*/
30		30
31	/** @addtogroup generic	31	/** @addtogroup generic
32	* @{	32	* @{
33	*/	33	*/
34		34
35	/**	35	/**
36	* @file	36	* @file
37	* @brief Userspace ELF loader.	37	* @brief Userspace ELF loader.
38	*	38	*
39	* This module allows loading ELF binaries (both executables and	39	* This module allows loading ELF binaries (both executables and
40	* shared objects) from VFS. The current implementation allocates	40	* shared objects) from VFS. The current implementation allocates
41	* anonymous memory, fills it with segment data and then adjusts	41	* anonymous memory, fills it with segment data and then adjusts
42	* the memory areas' flags to the final value. In the future,	42	* the memory areas' flags to the final value. In the future,
43	* the segments will be mapped directly from the file.	43	* the segments will be mapped directly from the file.
44	*/	44	*/
45		45
46	#include <stdio.h>	46	#include <stdio.h>
47	#include <sys/types.h>	47	#include <sys/types.h>
48	#include <align.h>	48	#include <align.h>
49	#include <assert.h>	49	#include <assert.h>
50	#include <as.h>	50	#include <as.h>
51	#include <unistd.h>	51	#include <unistd.h>
52	#include <fcntl.h>	52	#include <fcntl.h>
53		53
54	#include "elf.h"	54	#include "elf.h"
55	#include "pcb.h"	55	#include "pcb.h"
56	#include "elf_load.h"	56	#include "elf_load.h"
57	#include "arch.h"	57	#include "arch.h"
58		58
59	static char *error_codes[] = {	59	static char *error_codes[] = {
60	"no error",	60	"no error",
61	"invalid image",	61	"invalid image",
62	"address space error",	62	"address space error",
63	"incompatible image",	63	"incompatible image",
64	"unsupported image type",	64	"unsupported image type",
65	"irrecoverable error"	65	"irrecoverable error"
66	};	66	};
67		67
68	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias);	68	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias);
69	static int segment_header(elf_ld_t elf, elf_segment_header_t entry);	69	static int segment_header(elf_ld_t elf, elf_segment_header_t entry);
70	static int section_header(elf_ld_t elf, elf_section_header_t entry);	70	static int section_header(elf_ld_t elf, elf_section_header_t entry);
71	static int load_segment(elf_ld_t elf, elf_segment_header_t entry);	71	static int load_segment(elf_ld_t elf, elf_segment_header_t entry);
72		72
73	/** Load ELF binary from a file.	73	/** Load ELF binary from a file.
74	*	74	*
75	* Load an ELF binary from the specified file. If the file is	75	* Load an ELF binary from the specified file. If the file is
76	* an executable program, it is loaded unbiased. If it is a shared	76	* an executable program, it is loaded unbiased. If it is a shared
77	* object, it is loaded with the bias @a so_bias. Some information	77	* object, it is loaded with the bias @a so_bias. Some information
78	* extracted from the binary is stored in a elf_info_t structure	78	* extracted from the binary is stored in a elf_info_t structure
79	* pointed to by @a info.	79	* pointed to by @a info.
80	*	80	*
81	* @param file_name Path to the ELF file.	81	* @param file_name Path to the ELF file.
82	* @param so_bias Bias to use if the file is a shared object.	82	* @param so_bias Bias to use if the file is a shared object.
83	* @param info Pointer to a structure for storing information	83	* @param info Pointer to a structure for storing information
84	* extracted from the binary.	84	* extracted from the binary.
85	*	85	*
86	* @return EOK on success or negative error code.	86	* @return EOK on success or negative error code.
87	*/	87	*/
88	int elf_load_file(char file_name, size_t so_bias, elf_info_t info)	88	int elf_load_file(char file_name, size_t so_bias, elf_info_t info)
89	{	89	{
90	elf_ld_t elf;	90	elf_ld_t elf;
91		91
92	int fd;	92	int fd;
93	int rc;	93	int rc;
94		94
95	// printf("open and read '%s'...\n", file_name);	95	// printf("open and read '%s'...\n", file_name);
96		96
97	fd = open(file_name, O_RDONLY);	97	fd = open(file_name, O_RDONLY);
98	if (fd < 0) {	98	if (fd < 0) {
99	printf("failed opening file\n");	99	printf("failed opening file\n");
100	return -1;	100	return -1;
101	}	101	}
102		102
103	elf.fd = fd;	103	elf.fd = fd;
104	elf.info = info;	104	elf.info = info;
105		105
106	rc = elf_load(&elf, so_bias);	106	rc = elf_load(&elf, so_bias);
107		107
108	close(fd);	108	close(fd);
109		109
110	return rc;	110	return rc;
111	}	111	}
112		112
113	/** Run an ELF executable.	113	/** Run an ELF executable.
114	*	114	*
115	* Transfers control to the entry point of an ELF executable loaded	115	* Transfers control to the entry point of an ELF executable loaded
116	* earlier with elf_load_file(). This function does not return.	116	* earlier with elf_load_file(). This function does not return.
117	*	117	*
118	* @param info Info structure filled earlier by elf_load_file()	118	* @param info Info structure filled earlier by elf_load_file()
119	*/	119	*/
120	void elf_run(elf_info_t *info)	120	void elf_run(elf_info_t *info)
121	{	121	{
122	program_run(info->entry);	122	program_run(info->entry);
123		123
124	/* not reached */	124	/* not reached */
125	}	125	}
126		126
127	/** Create the program control block (PCB).	127	/** Create the program control block (PCB).
128	*	128	*
129	* Create and install the program control block, initialising it	129	* Create and install the program control block, initialising it
130	* with program information from @a info.	130	* with program information from @a info.
131	*	131	*
132	* @param info Program info structure	132	* @param info Program info structure
133	* @return EOK on success or negative error code	133	* @return EOK on success or negative error code
134	*/	134	*/
135	int elf_create_pcb(elf_info_t *info)	135	int elf_create_pcb(elf_info_t *info)
136	{	136	{
137	pcb_t *pcb;	137	pcb_t *pcb;
138	void *a;	138	void *a;
139		139
140	pcb = __pcb_get();	140	pcb = __pcb_get();
141		141
142	a = as_area_create(pcb, sizeof(pcb_t), AS_AREA_READ \| AS_AREA_WRITE);	142	a = as_area_create(pcb, sizeof(pcb_t), AS_AREA_READ \| AS_AREA_WRITE);
143	if (a == (void *)(-1)) {	143	if (a == (void *)(-1)) {
144	printf("elf_create_pcb: memory mapping failed\n");	144	printf("elf_create_pcb: memory mapping failed\n");
145	return EE_MEMORY;	145	return EE_MEMORY;
146	}	146	}
147		147
148	pcb->entry = info->entry;	148	pcb->entry = info->entry;
149	pcb->dynamic = info->dynamic;	149	pcb->dynamic = info->dynamic;
150		150
151	return 0;	151	return 0;
152	}	152	}
153		153
154		154
155	/** Load an ELF binary.	155	/** Load an ELF binary.
156	*	156	*
157	* The @a elf structure contains the loader state, including	157	* The @a elf structure contains the loader state, including
158	* an open file, from which the binary will be loaded,	158	* an open file, from which the binary will be loaded,
159	* a pointer to the @c info structure etc.	159	* a pointer to the @c info structure etc.
160	*	160	*
161	* @param elf Pointer to loader state buffer.	161	* @param elf Pointer to loader state buffer.
162	* @param so_bias Bias to use if the file is a shared object.	162	* @param so_bias Bias to use if the file is a shared object.
163	* @return EE_OK on success or EE_xx error code.	163	* @return EE_OK on success or EE_xx error code.
164	*/	164	*/
165	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias)	165	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias)
166	{	166	{
167	elf_header_t header_buf;	167	elf_header_t header_buf;
168	elf_header_t *header = &header_buf;	168	elf_header_t *header = &header_buf;
169	int i, rc;	169	int i, rc;
170		170
171	rc = read(elf->fd, header, sizeof(elf_header_t));	171	rc = read(elf->fd, header, sizeof(elf_header_t));
172	if (rc < 0) {	172	if (rc < 0) {
173	printf("read error\n");	173	printf("read error\n");
174	return EE_INVALID;	174	return EE_INVALID;
175	}	175	}
176		176
177	elf->header = header;	177	elf->header = header;
178		178
179	// printf("ELF-load:");	179	// printf("ELF-load:");
180	/* Identify ELF */	180	/* Identify ELF */
181	if (header->e_ident[EI_MAG0] != ELFMAG0 \|\|	181	if (header->e_ident[EI_MAG0] != ELFMAG0 \|\|
182	header->e_ident[EI_MAG1] != ELFMAG1 \|\|	182	header->e_ident[EI_MAG1] != ELFMAG1 \|\|
183	header->e_ident[EI_MAG2] != ELFMAG2 \|\|	183	header->e_ident[EI_MAG2] != ELFMAG2 \|\|
184	header->e_ident[EI_MAG3] != ELFMAG3) {	184	header->e_ident[EI_MAG3] != ELFMAG3) {
185	printf("invalid header\n");	185	printf("invalid header\n");
186	return EE_INVALID;	186	return EE_INVALID;
187	}	187	}
188		188
189	/* Identify ELF compatibility */	189	/* Identify ELF compatibility */
190	if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING \|\|	190	if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING \|\|
191	header->e_machine != ELF_MACHINE \|\|	191	header->e_machine != ELF_MACHINE \|\|
192	header->e_ident[EI_VERSION] != EV_CURRENT \|\|	192	header->e_ident[EI_VERSION] != EV_CURRENT \|\|
193	header->e_version != EV_CURRENT \|\|	193	header->e_version != EV_CURRENT \|\|
194	header->e_ident[EI_CLASS] != ELF_CLASS) {	194	header->e_ident[EI_CLASS] != ELF_CLASS) {
195	printf("incompatible data/version/class\n");	195	printf("incompatible data/version/class\n");
196	return EE_INCOMPATIBLE;	196	return EE_INCOMPATIBLE;
197	}	197	}
198		198
199	if (header->e_phentsize != sizeof(elf_segment_header_t)) {	199	if (header->e_phentsize != sizeof(elf_segment_header_t)) {
200	printf("e_phentsize:%d != %d\n", header->e_phentsize,	200	printf("e_phentsize:%d != %d\n", header->e_phentsize,
201	sizeof(elf_segment_header_t));	201	sizeof(elf_segment_header_t));
202	return EE_INCOMPATIBLE;	202	return EE_INCOMPATIBLE;
203	}	203	}
204		204
205	if (header->e_shentsize != sizeof(elf_section_header_t)) {	205	if (header->e_shentsize != sizeof(elf_section_header_t)) {
206	printf("e_shentsize:%d != %d\n", header->e_shentsize,	206	printf("e_shentsize:%d != %d\n", header->e_shentsize,
207	sizeof(elf_section_header_t));	207	sizeof(elf_section_header_t));
208	return EE_INCOMPATIBLE;	208	return EE_INCOMPATIBLE;
209	}	209	}
210		210
211	/* Check if the object type is supported. */	211	/* Check if the object type is supported. */
212	if (header->e_type != ET_EXEC && header->e_type != ET_DYN) {	212	if (header->e_type != ET_EXEC && header->e_type != ET_DYN) {
213	printf("Object type %d is not supported\n", header->e_type);	213	printf("Object type %d is not supported\n", header->e_type);
214	return EE_UNSUPPORTED;	214	return EE_UNSUPPORTED;
215	}	215	}
216		216
217	/* Shared objects can be loaded with a bias */	217	/* Shared objects can be loaded with a bias */
218	// printf("Object type: %d\n", header->e_type);	218	// printf("Object type: %d\n", header->e_type);
219	if (header->e_type == ET_DYN)	219	if (header->e_type == ET_DYN)
220	elf->bias = so_bias;	220	elf->bias = so_bias;
221	else	221	else
222	elf->bias = 0;	222	elf->bias = 0;
223		223
224	// printf("Bias set to 0x%x\n", elf->bias);	224	// printf("Bias set to 0x%x\n", elf->bias);
225	elf->info->interp = NULL;	225	elf->info->interp = NULL;
226	elf->info->dynamic = NULL;	226	elf->info->dynamic = NULL;
227		227
228	// printf("parse segments\n");	228	// printf("parse segments\n");
229		229
230	/* Walk through all segment headers and process them. */	230	/* Walk through all segment headers and process them. */
231	for (i = 0; i < header->e_phnum; i++) {	231	for (i = 0; i < header->e_phnum; i++) {
232	elf_segment_header_t segment_hdr;	232	elf_segment_header_t segment_hdr;
233		233
234	/* Seek to start of segment header */	234	/* Seek to start of segment header */
235	lseek(elf->fd, header->e_phoff	235	lseek(elf->fd, header->e_phoff
236	+ i * sizeof(elf_segment_header_t), SEEK_SET);	236	+ i * sizeof(elf_segment_header_t), SEEK_SET);
237		237
238	rc = read(elf->fd, &segment_hdr, sizeof(elf_segment_header_t));	238	rc = read(elf->fd, &segment_hdr, sizeof(elf_segment_header_t));
239	if (rc < 0) { printf("read error\n"); return EE_INVALID; }	239	if (rc < 0) { printf("read error\n"); return EE_INVALID; }
240		240
241	rc = segment_header(elf, &segment_hdr);	241	rc = segment_header(elf, &segment_hdr);
242	if (rc != EE_OK)	242	if (rc != EE_OK)
243	return rc;	243	return rc;
244	}	244	}
245		245
246	// printf("parse sections\n");	246	// printf("parse sections\n");
247		247
248	/* Inspect all section headers and proccess them. */	248	/* Inspect all section headers and proccess them. */
249	for (i = 0; i < header->e_shnum; i++) {	249	for (i = 0; i < header->e_shnum; i++) {
250	elf_section_header_t section_hdr;	250	elf_section_header_t section_hdr;
251		251
252	/* Seek to start of section header */	252	/* Seek to start of section header */
253	lseek(elf->fd, header->e_shoff	253	lseek(elf->fd, header->e_shoff
254	+ i * sizeof(elf_section_header_t), SEEK_SET);	254	+ i * sizeof(elf_section_header_t), SEEK_SET);
255		255
256	rc = read(elf->fd, &section_hdr, sizeof(elf_section_header_t));	256	rc = read(elf->fd, &section_hdr, sizeof(elf_section_header_t));
257	if (rc < 0) { printf("read error\n"); return EE_INVALID; }	257	if (rc < 0) { printf("read error\n"); return EE_INVALID; }
258		258
259	rc = section_header(elf, &section_hdr);	259	rc = section_header(elf, &section_hdr);
260	if (rc != EE_OK)	260	if (rc != EE_OK)
261	return rc;	261	return rc;
262	}	262	}
263		263
264	elf->info->entry =	264	elf->info->entry =
265	(entry_point_t)((uint8_t *)header->e_entry + elf->bias);	265	(entry_point_t)((uint8_t *)header->e_entry + elf->bias);
266		266
267	// printf("done\n");	267	// printf("done\n");
268		268
269	return EE_OK;	269	return EE_OK;
270	}	270	}
271		271
272	/** Print error message according to error code.	272	/** Print error message according to error code.
273	*	273	*
274	* @param rc Return code returned by elf_load().	274	* @param rc Return code returned by elf_load().
275	*	275	*
276	* @return NULL terminated description of error.	276	* @return NULL terminated description of error.
277	*/	277	*/
278	char *elf_error(unsigned int rc)	278	char *elf_error(unsigned int rc)
279	{	279	{
280	assert(rc < sizeof(error_codes) / sizeof(char *));	280	assert(rc < sizeof(error_codes) / sizeof(char *));
281		281
282	return error_codes[rc];	282	return error_codes[rc];
283	}	283	}
284		284
285	/** Process segment header.	285	/** Process segment header.
286	*	286	*
287	* @param entry Segment header.	287	* @param entry Segment header.
288	*	288	*
289	* @return EE_OK on success, error code otherwise.	289	* @return EE_OK on success, error code otherwise.
290	*/	290	*/
291	static int segment_header(elf_ld_t elf, elf_segment_header_t entry)	291	static int segment_header(elf_ld_t elf, elf_segment_header_t entry)
292	{	292	{
293	switch (entry->p_type) {	293	switch (entry->p_type) {
294	case PT_NULL:	294	case PT_NULL:
295	case PT_PHDR:	295	case PT_PHDR:
296	break;	296	break;
297	case PT_LOAD:	297	case PT_LOAD:
298	return load_segment(elf, entry);	298	return load_segment(elf, entry);
299	break;	299	break;
300	case PT_INTERP:	300	case PT_INTERP:
301	/* Assume silently interp == "/rtld.so" */	301	/* Assume silently interp == "/rtld.so" */
302	elf->info->interp = "/rtld.so";	302	elf->info->interp = "/rtld.so";
303	break;	303	break;
304	case PT_DYNAMIC:	304	case PT_DYNAMIC:
305	case PT_SHLIB:	305	case PT_SHLIB:
306	case PT_NOTE:	306	case PT_NOTE:
307	case PT_LOPROC:	307	case PT_LOPROC:
308	case PT_HIPROC:	308	case PT_HIPROC:
309	default:	309	default:
310	printf("segment p_type %d unknown\n", entry->p_type);	310	printf("segment p_type %d unknown\n", entry->p_type);
311	return EE_UNSUPPORTED;	311	return EE_UNSUPPORTED;
312	break;	312	break;
313	}	313	}
314	return EE_OK;	314	return EE_OK;
315	}	315	}
316		316
317	/** Load segment described by program header entry.	317	/** Load segment described by program header entry.
318	*	318	*
319	* @param elf Loader state.	319	* @param elf Loader state.
320	* @param entry Program header entry describing segment to be loaded.	320	* @param entry Program header entry describing segment to be loaded.
321	*	321	*
322	* @return EE_OK on success, error code otherwise.	322	* @return EE_OK on success, error code otherwise.
323	*/	323	*/
324	int load_segment(elf_ld_t elf, elf_segment_header_t entry)	324	int load_segment(elf_ld_t elf, elf_segment_header_t entry)
325	{	325	{
326	void *a;	326	void *a;
327	int flags = 0;	327	int flags = 0;
328	uintptr_t bias;	328	uintptr_t bias;
329	uintptr_t base;	329	uintptr_t base;
330	size_t mem_sz;	330	size_t mem_sz;
331	int rc;	331	int rc;
332		332
333	// printf("load segment at addr 0x%x, size 0x%x\n", entry->p_vaddr,	333	// printf("load segment at addr 0x%x, size 0x%x\n", entry->p_vaddr,
334	// entry->p_memsz);	334	// entry->p_memsz);
335		335
336	bias = elf->bias;	336	bias = elf->bias;
337		337
338	if (entry->p_align > 1) {	338	if (entry->p_align > 1) {
339	if ((entry->p_offset % entry->p_align) !=	339	if ((entry->p_offset % entry->p_align) !=
340	(entry->p_vaddr % entry->p_align)) {	340	(entry->p_vaddr % entry->p_align)) {
341	printf("align check 1 failed offset%%align=%d, vaddr%%align=%d\n",	341	printf("align check 1 failed offset%%align=%d, vaddr%%align=%d\n",
342	entry->p_offset % entry->p_align,	342	entry->p_offset % entry->p_align,
343	entry->p_vaddr % entry->p_align	343	entry->p_vaddr % entry->p_align
344	);	344	);
345	return EE_INVALID;	345	return EE_INVALID;
346	}	346	}
347	}	347	}
348		348
349	/* Final flags that will be set for the memory area */	349	/* Final flags that will be set for the memory area */
350		350
351	if (entry->p_flags & PF_X)	351	if (entry->p_flags & PF_X)
352	flags \|= AS_AREA_EXEC;	352	flags \|= AS_AREA_EXEC;
353	if (entry->p_flags & PF_W)	353	if (entry->p_flags & PF_W)
354	flags \|= AS_AREA_WRITE;	354	flags \|= AS_AREA_WRITE;
355	if (entry->p_flags & PF_R)	355	if (entry->p_flags & PF_R)
356	flags \|= AS_AREA_READ;	356	flags \|= AS_AREA_READ;
357	flags \|= AS_AREA_CACHEABLE;	357	flags \|= AS_AREA_CACHEABLE;
358		358
359	base = ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE);	359	base = ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE);
360	mem_sz = entry->p_memsz + (entry->p_vaddr - base);	360	mem_sz = entry->p_memsz + (entry->p_vaddr - base);
361		361
362	// printf("map to p_vaddr=0x%x-0x%x...\n", entry->p_vaddr + bias,	362	// printf("map to p_vaddr=0x%x-0x%x...\n", entry->p_vaddr + bias,
363	// entry->p_vaddr + bias + ALIGN_UP(entry->p_memsz, PAGE_SIZE));	363	// entry->p_vaddr + bias + ALIGN_UP(entry->p_memsz, PAGE_SIZE));
364		364
365	/*	365	/*
366	* For the course of loading, the area needs to be readable	366	* For the course of loading, the area needs to be readable
367	* and writeable.	367	* and writeable.
368	*/	368	*/
369	a = as_area_create((uint8_t *)base + bias,	369	a = as_area_create((uint8_t *)base + bias,
370	mem_sz, AS_AREA_READ \| AS_AREA_WRITE \| AS_AREA_CACHEABLE);	370	mem_sz, AS_AREA_READ \| AS_AREA_WRITE \| AS_AREA_CACHEABLE);
371	if (a == (void *)(-1)) {	371	if (a == (void *)(-1)) {
372	printf("memory mapping failed\n");	372	printf("memory mapping failed\n");
373	return EE_MEMORY;	373	return EE_MEMORY;
374	}	374	}
375		375
376	// printf("as_area_create(0x%lx, 0x%x, %d) -> 0x%lx\n",	376	// printf("as_area_create(0x%lx, 0x%x, %d) -> 0x%lx\n",
377	// entry->p_vaddr+bias, entry->p_memsz, flags, (uintptr_t)a);	377	// entry->p_vaddr+bias, entry->p_memsz, flags, (uintptr_t)a);
378		378
379	/*	379	/*
380	* Load segment data	380	* Load segment data
381	*/	381	*/
382	// printf("seek to %d\n", entry->p_offset);	382	// printf("seek to %d\n", entry->p_offset);
383	rc = lseek(elf->fd, entry->p_offset, SEEK_SET);	383	rc = lseek(elf->fd, entry->p_offset, SEEK_SET);
384	if (rc < 0) { printf("seek error\n"); return EE_INVALID; }	384	if (rc < 0) { printf("seek error\n"); return EE_INVALID; }
385		385
386	// printf("read 0x%x bytes to address 0x%x\n", entry->p_filesz, entry->p_vaddr+bias);	386	// printf("read 0x%x bytes to address 0x%x\n", entry->p_filesz, entry->p_vaddr+bias);
387	/* rc = read(fd, (void *)(entry->p_vaddr + bias), entry->p_filesz);	387	/* rc = read(fd, (void *)(entry->p_vaddr + bias), entry->p_filesz);
388	if (rc < 0) { printf("read error\n"); return EE_INVALID; }*/	388	if (rc < 0) { printf("read error\n"); return EE_INVALID; }*/
389		389
390	/* Long reads are not possible yet. Load segment picewise */	390	/* Long reads are not possible yet. Load segment picewise */
391		391
392	unsigned left, now;	392	unsigned left, now;
393	uint8_t *dp;	393	uint8_t *dp;
394		394
395	left = entry->p_filesz;	395	left = entry->p_filesz;
396	dp = (uint8_t *)(entry->p_vaddr + bias);	396	dp = (uint8_t *)(entry->p_vaddr + bias);
397		397
398	while (left > 0) {	398	while (left > 0) {
399	now = 16384;	399	now = 16384;
400	if (now > left) now = left;	400	if (now > left) now = left;
401		401
402	// printf("read %d...", now);	402	// printf("read %d...", now);
403	rc = read(elf->fd, dp, now);	403	rc = read(elf->fd, dp, now);
404	// printf("->%d\n", rc);	404	// printf("->%d\n", rc);
405		405
406	if (rc < 0) { printf("read error\n"); return EE_INVALID; }	406	if (rc < 0) { printf("read error\n"); return EE_INVALID; }
407		407
408	left -= now;	408	left -= now;
409	dp += now;	409	dp += now;
410	}	410	}
411		411
412	// printf("set area flags to %d\n", flags);	412	// printf("set area flags to %d\n", flags);
413	rc = as_area_change_flags((uint8_t *)entry->p_vaddr + bias, flags);	413	rc = as_area_change_flags((uint8_t *)entry->p_vaddr + bias, flags);
414	if (rc != 0) {	414	if (rc != 0) {
415	printf("failed to set memory area flags\n");	415	printf("failed to set memory area flags\n");
416	return EE_MEMORY;	416	return EE_MEMORY;
417	}	417	}
418		418
419	return EE_OK;	419	return EE_OK;
420	}	420	}
421		421
422	/** Process section header.	422	/** Process section header.
423	*	423	*
424	* @param elf Loader state.	424	* @param elf Loader state.
425	* @param entry Segment header.	425	* @param entry Segment header.
426	*	426	*
427	* @return EE_OK on success, error code otherwise.	427	* @return EE_OK on success, error code otherwise.
428	*/	428	*/
429	static int section_header(elf_ld_t elf, elf_section_header_t entry)	429	static int section_header(elf_ld_t elf, elf_section_header_t entry)
430	{	430	{
431	switch (entry->sh_type) {	431	switch (entry->sh_type) {
432	case SHT_PROGBITS:	432	case SHT_PROGBITS:
433	if (entry->sh_flags & SHF_TLS) {	433	if (entry->sh_flags & SHF_TLS) {
434	/* .tdata */	434	/* .tdata */
435	}	435	}
436	break;	436	break;
437	case SHT_NOBITS:	437	case SHT_NOBITS:
438	if (entry->sh_flags & SHF_TLS) {	438	if (entry->sh_flags & SHF_TLS) {
439	/* .tbss */	439	/* .tbss */
440	}	440	}
441	break;	441	break;
442	case SHT_DYNAMIC:	442	case SHT_DYNAMIC:
443	/* Record pointer to dynamic section into info structure */	443	/* Record pointer to dynamic section into info structure */
444	elf->info->dynamic =	444	elf->info->dynamic =
445	(void )((uint8_t )entry->sh_addr + elf->bias);	445	(void )((uint8_t )entry->sh_addr + elf->bias);
446	printf("dynamic section found at 0x%x\n",	446	printf("dynamic section found at 0x%x\n",
447	(uintptr_t)elf->info->dynamic);	447	(uintptr_t)elf->info->dynamic);
448	break;	448	break;
449	default:	449	default:
450	break;	450	break;
451	}	451	}
452		452
453	return EE_OK;	453	return EE_OK;
454	}	454	}
455		455
456	/** @}	456	/** @}
457	*/	457	*/
458		458

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(root)/branches/dynload/uspace/srv/loader/elf_load.c @ 3672 – Rev 3155 → 3157