WebSVN – HelenOS – Diff – /trunk/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 <smc.h>
#include <loader/pcb.h>
 
#include "elf.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, pcb_t *pcb)
{
    program_run(info->entry, pcb);
 
    /* not reached */
}
 
/** Create the program control block (PCB).
 *
 * Fills the program control block @a pcb with information from
 * @a info.
 *
 * @param info  Program info structure
 * @return EOK on success or negative error code
 */
void elf_create_pcb(elf_info_t *info, pcb_t *pcb)
{
    pcb->entry = info->entry;
    pcb->dynamic = info->dynamic;
}
 
 
/** 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;
    }
 
    if (flags & AS_AREA_EXEC) {
        /* Enforce SMC coherence for the segment */
        if (smc_coherence(entry->p_vaddr + bias, entry->p_filesz))
            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 3222	Rev 3223
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	#include <smc.h>	53	#include <smc.h>
54	#include <loader/pcb.h>	54	#include <loader/pcb.h>
55		55
56	#include "elf.h"	56	#include "elf.h"
57	#include "elf_load.h"	57	#include "elf_load.h"
58	#include "arch.h"	58	#include "arch.h"
59		59
60	static char *error_codes[] = {	60	static char *error_codes[] = {
61	"no error",	61	"no error",
62	"invalid image",	62	"invalid image",
63	"address space error",	63	"address space error",
64	"incompatible image",	64	"incompatible image",
65	"unsupported image type",	65	"unsupported image type",
66	"irrecoverable error"	66	"irrecoverable error"
67	};	67	};
68		68
69	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias);	69	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias);
70	static int segment_header(elf_ld_t elf, elf_segment_header_t entry);	70	static int segment_header(elf_ld_t elf, elf_segment_header_t entry);
71	static int section_header(elf_ld_t elf, elf_section_header_t entry);	71	static int section_header(elf_ld_t elf, elf_section_header_t entry);
72	static int load_segment(elf_ld_t elf, elf_segment_header_t entry);	72	static int load_segment(elf_ld_t elf, elf_segment_header_t entry);
73		73
74	/** Load ELF binary from a file.	74	/** Load ELF binary from a file.
75	*	75	*
76	* Load an ELF binary from the specified file. If the file is	76	* Load an ELF binary from the specified file. If the file is
77	* an executable program, it is loaded unbiased. If it is a shared	77	* an executable program, it is loaded unbiased. If it is a shared
78	* object, it is loaded with the bias @a so_bias. Some information	78	* object, it is loaded with the bias @a so_bias. Some information
79	* extracted from the binary is stored in a elf_info_t structure	79	* extracted from the binary is stored in a elf_info_t structure
80	* pointed to by @a info.	80	* pointed to by @a info.
81	*	81	*
82	* @param file_name Path to the ELF file.	82	* @param file_name Path to the ELF file.
83	* @param so_bias Bias to use if the file is a shared object.	83	* @param so_bias Bias to use if the file is a shared object.
84	* @param info Pointer to a structure for storing information	84	* @param info Pointer to a structure for storing information
85	* extracted from the binary.	85	* extracted from the binary.
86	*	86	*
87	* @return EOK on success or negative error code.	87	* @return EOK on success or negative error code.
88	*/	88	*/
89	int elf_load_file(char file_name, size_t so_bias, elf_info_t info)	89	int elf_load_file(char file_name, size_t so_bias, elf_info_t info)
90	{	90	{
91	elf_ld_t elf;	91	elf_ld_t elf;
92		92
93	int fd;	93	int fd;
94	int rc;	94	int rc;
95		95
96	// printf("open and read '%s'...\n", file_name);	96	// printf("open and read '%s'...\n", file_name);
97		97
98	fd = open(file_name, O_RDONLY);	98	fd = open(file_name, O_RDONLY);
99	if (fd < 0) {	99	if (fd < 0) {
100	printf("failed opening file\n");	100	printf("failed opening file\n");
101	return -1;	101	return -1;
102	}	102	}
103		103
104	elf.fd = fd;	104	elf.fd = fd;
105	elf.info = info;	105	elf.info = info;
106		106
107	rc = elf_load(&elf, so_bias);	107	rc = elf_load(&elf, so_bias);
108		108
109	close(fd);	109	close(fd);
110		110
111	return rc;	111	return rc;
112	}	112	}
113		113
114	/** Run an ELF executable.	114	/** Run an ELF executable.
115	*	115	*
116	* Transfers control to the entry point of an ELF executable loaded	116	* Transfers control to the entry point of an ELF executable loaded
117	* earlier with elf_load_file(). This function does not return.	117	* earlier with elf_load_file(). This function does not return.
118	*	118	*
119	* @param info Info structure filled earlier by elf_load_file()	119	* @param info Info structure filled earlier by elf_load_file()
120	*/	120	*/
121	void elf_run(elf_info_t info, pcb_t pcb)	121	void elf_run(elf_info_t info, pcb_t pcb)
122	{	122	{
123	program_run(info->entry, pcb);	123	program_run(info->entry, pcb);
124		124
125	/* not reached */	125	/* not reached */
126	}	126	}
127		127
128	/** Create the program control block (PCB).	128	/** Create the program control block (PCB).
129	*	129	*
130	* Fills the program control block @a pcb with information from	130	* Fills the program control block @a pcb with information from
131	* @a info.	131	* @a info.
132	*	132	*
133	* @param info Program info structure	133	* @param info Program info structure
134	* @return EOK on success or negative error code	134	* @return EOK on success or negative error code
135	*/	135	*/
136	void elf_create_pcb(elf_info_t info, pcb_t pcb)	136	void elf_create_pcb(elf_info_t info, pcb_t pcb)
137	{	137	{
138	pcb->entry = info->entry;	138	pcb->entry = info->entry;
139	pcb->dynamic = info->dynamic;	139	pcb->dynamic = info->dynamic;
140	}	140	}
141		141
142		142
143	/** Load an ELF binary.	143	/** Load an ELF binary.
144	*	144	*
145	* The @a elf structure contains the loader state, including	145	* The @a elf structure contains the loader state, including
146	* an open file, from which the binary will be loaded,	146	* an open file, from which the binary will be loaded,
147	* a pointer to the @c info structure etc.	147	* a pointer to the @c info structure etc.
148	*	148	*
149	* @param elf Pointer to loader state buffer.	149	* @param elf Pointer to loader state buffer.
150	* @param so_bias Bias to use if the file is a shared object.	150	* @param so_bias Bias to use if the file is a shared object.
151	* @return EE_OK on success or EE_xx error code.	151	* @return EE_OK on success or EE_xx error code.
152	*/	152	*/
153	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias)	153	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias)
154	{	154	{
155	elf_header_t header_buf;	155	elf_header_t header_buf;
156	elf_header_t *header = &header_buf;	156	elf_header_t *header = &header_buf;
157	int i, rc;	157	int i, rc;
158		158
159	rc = read(elf->fd, header, sizeof(elf_header_t));	159	rc = read(elf->fd, header, sizeof(elf_header_t));
160	if (rc < 0) {	160	if (rc < 0) {
161	printf("read error\n");	161	printf("read error\n");
162	return EE_INVALID;	162	return EE_INVALID;
163	}	163	}
164		164
165	elf->header = header;	165	elf->header = header;
166		166
167	// printf("ELF-load:");	167	// printf("ELF-load:");
168	/* Identify ELF */	168	/* Identify ELF */
169	if (header->e_ident[EI_MAG0] != ELFMAG0 \|\|	169	if (header->e_ident[EI_MAG0] != ELFMAG0 \|\|
170	header->e_ident[EI_MAG1] != ELFMAG1 \|\|	170	header->e_ident[EI_MAG1] != ELFMAG1 \|\|
171	header->e_ident[EI_MAG2] != ELFMAG2 \|\|	171	header->e_ident[EI_MAG2] != ELFMAG2 \|\|
172	header->e_ident[EI_MAG3] != ELFMAG3) {	172	header->e_ident[EI_MAG3] != ELFMAG3) {
173	printf("invalid header\n");	173	printf("invalid header\n");
174	return EE_INVALID;	174	return EE_INVALID;
175	}	175	}
176		176
177	/* Identify ELF compatibility */	177	/* Identify ELF compatibility */
178	if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING \|\|	178	if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING \|\|
179	header->e_machine != ELF_MACHINE \|\|	179	header->e_machine != ELF_MACHINE \|\|
180	header->e_ident[EI_VERSION] != EV_CURRENT \|\|	180	header->e_ident[EI_VERSION] != EV_CURRENT \|\|
181	header->e_version != EV_CURRENT \|\|	181	header->e_version != EV_CURRENT \|\|
182	header->e_ident[EI_CLASS] != ELF_CLASS) {	182	header->e_ident[EI_CLASS] != ELF_CLASS) {
183	printf("incompatible data/version/class\n");	183	printf("incompatible data/version/class\n");
184	return EE_INCOMPATIBLE;	184	return EE_INCOMPATIBLE;
185	}	185	}
186		186
187	if (header->e_phentsize != sizeof(elf_segment_header_t)) {	187	if (header->e_phentsize != sizeof(elf_segment_header_t)) {
188	printf("e_phentsize:%d != %d\n", header->e_phentsize,	188	printf("e_phentsize:%d != %d\n", header->e_phentsize,
189	sizeof(elf_segment_header_t));	189	sizeof(elf_segment_header_t));
190	return EE_INCOMPATIBLE;	190	return EE_INCOMPATIBLE;
191	}	191	}
192		192
193	if (header->e_shentsize != sizeof(elf_section_header_t)) {	193	if (header->e_shentsize != sizeof(elf_section_header_t)) {
194	printf("e_shentsize:%d != %d\n", header->e_shentsize,	194	printf("e_shentsize:%d != %d\n", header->e_shentsize,
195	sizeof(elf_section_header_t));	195	sizeof(elf_section_header_t));
196	return EE_INCOMPATIBLE;	196	return EE_INCOMPATIBLE;
197	}	197	}
198		198
199	/* Check if the object type is supported. */	199	/* Check if the object type is supported. */
200	if (header->e_type != ET_EXEC && header->e_type != ET_DYN) {	200	if (header->e_type != ET_EXEC && header->e_type != ET_DYN) {
201	printf("Object type %d is not supported\n", header->e_type);	201	printf("Object type %d is not supported\n", header->e_type);
202	return EE_UNSUPPORTED;	202	return EE_UNSUPPORTED;
203	}	203	}
204		204
205	/* Shared objects can be loaded with a bias */	205	/* Shared objects can be loaded with a bias */
206	// printf("Object type: %d\n", header->e_type);	206	// printf("Object type: %d\n", header->e_type);
207	if (header->e_type == ET_DYN)	207	if (header->e_type == ET_DYN)
208	elf->bias = so_bias;	208	elf->bias = so_bias;
209	else	209	else
210	elf->bias = 0;	210	elf->bias = 0;
211		211
212	// printf("Bias set to 0x%x\n", elf->bias);	212	// printf("Bias set to 0x%x\n", elf->bias);
213	elf->info->interp = NULL;	213	elf->info->interp = NULL;
214	elf->info->dynamic = NULL;	214	elf->info->dynamic = NULL;
215		215
216	// printf("parse segments\n");	216	// printf("parse segments\n");
217		217
218	/* Walk through all segment headers and process them. */	218	/* Walk through all segment headers and process them. */
219	for (i = 0; i < header->e_phnum; i++) {	219	for (i = 0; i < header->e_phnum; i++) {
220	elf_segment_header_t segment_hdr;	220	elf_segment_header_t segment_hdr;
221		221
222	/* Seek to start of segment header */	222	/* Seek to start of segment header */
223	lseek(elf->fd, header->e_phoff	223	lseek(elf->fd, header->e_phoff
224	+ i * sizeof(elf_segment_header_t), SEEK_SET);	224	+ i * sizeof(elf_segment_header_t), SEEK_SET);
225		225
226	rc = read(elf->fd, &segment_hdr, sizeof(elf_segment_header_t));	226	rc = read(elf->fd, &segment_hdr, sizeof(elf_segment_header_t));
-		227	if (rc < 0) {
227	if (rc < 0) { printf("read error\n"); return EE_INVALID; }	228	printf("read error\n");
-		229	return EE_INVALID;
-		230	}
228		231
229	rc = segment_header(elf, &segment_hdr);	232	rc = segment_header(elf, &segment_hdr);
230	if (rc != EE_OK)	233	if (rc != EE_OK)
231	return rc;	234	return rc;
232	}	235	}
233		236
234	// printf("parse sections\n");	237	// printf("parse sections\n");
235		238
236	/* Inspect all section headers and proccess them. */	239	/* Inspect all section headers and proccess them. */
237	for (i = 0; i < header->e_shnum; i++) {	240	for (i = 0; i < header->e_shnum; i++) {
238	elf_section_header_t section_hdr;	241	elf_section_header_t section_hdr;
239		242
240	/* Seek to start of section header */	243	/* Seek to start of section header */
241	lseek(elf->fd, header->e_shoff	244	lseek(elf->fd, header->e_shoff
242	+ i * sizeof(elf_section_header_t), SEEK_SET);	245	+ i * sizeof(elf_section_header_t), SEEK_SET);
243		246
244	rc = read(elf->fd, &section_hdr, sizeof(elf_section_header_t));	247	rc = read(elf->fd, &section_hdr, sizeof(elf_section_header_t));
-		248	if (rc < 0) {
245	if (rc < 0) { printf("read error\n"); return EE_INVALID; }	249	printf("read error\n");
-		250	return EE_INVALID;
-		251	}
246		252
247	rc = section_header(elf, &section_hdr);	253	rc = section_header(elf, &section_hdr);
248	if (rc != EE_OK)	254	if (rc != EE_OK)
249	return rc;	255	return rc;
250	}	256	}
251		257
252	elf->info->entry =	258	elf->info->entry =
253	(entry_point_t)((uint8_t *)header->e_entry + elf->bias);	259	(entry_point_t)((uint8_t *)header->e_entry + elf->bias);
254		260
255	// printf("done\n");	261	// printf("done\n");
256		262
257	return EE_OK;	263	return EE_OK;
258	}	264	}
259		265
260	/** Print error message according to error code.	266	/** Print error message according to error code.
261	*	267	*
262	* @param rc Return code returned by elf_load().	268	* @param rc Return code returned by elf_load().
263	*	269	*
264	* @return NULL terminated description of error.	270	* @return NULL terminated description of error.
265	*/	271	*/
266	char *elf_error(unsigned int rc)	272	char *elf_error(unsigned int rc)
267	{	273	{
268	assert(rc < sizeof(error_codes) / sizeof(char *));	274	assert(rc < sizeof(error_codes) / sizeof(char *));
269		275
270	return error_codes[rc];	276	return error_codes[rc];
271	}	277	}
272		278
273	/** Process segment header.	279	/** Process segment header.
274	*	280	*
275	* @param entry Segment header.	281	* @param entry Segment header.
276	*	282	*
277	* @return EE_OK on success, error code otherwise.	283	* @return EE_OK on success, error code otherwise.
278	*/	284	*/
279	static int segment_header(elf_ld_t elf, elf_segment_header_t entry)	285	static int segment_header(elf_ld_t elf, elf_segment_header_t entry)
280	{	286	{
281	switch (entry->p_type) {	287	switch (entry->p_type) {
282	case PT_NULL:	288	case PT_NULL:
283	case PT_PHDR:	289	case PT_PHDR:
284	break;	290	break;
285	case PT_LOAD:	291	case PT_LOAD:
286	return load_segment(elf, entry);	292	return load_segment(elf, entry);
287	break;	293	break;
288	case PT_INTERP:	294	case PT_INTERP:
289	/* Assume silently interp == "/rtld.so" */	295	/* Assume silently interp == "/rtld.so" */
290	elf->info->interp = "/rtld.so";	296	elf->info->interp = "/rtld.so";
291	break;	297	break;
292	case PT_DYNAMIC:	298	case PT_DYNAMIC:
293	case PT_SHLIB:	299	case PT_SHLIB:
294	case PT_NOTE:	300	case PT_NOTE:
295	case PT_LOPROC:	301	case PT_LOPROC:
296	case PT_HIPROC:	302	case PT_HIPROC:
297	default:	303	default:
298	printf("segment p_type %d unknown\n", entry->p_type);	304	printf("segment p_type %d unknown\n", entry->p_type);
299	return EE_UNSUPPORTED;	305	return EE_UNSUPPORTED;
300	break;	306	break;
301	}	307	}
302	return EE_OK;	308	return EE_OK;
303	}	309	}
304		310
305	/** Load segment described by program header entry.	311	/** Load segment described by program header entry.
306	*	312	*
307	* @param elf Loader state.	313	* @param elf Loader state.
308	* @param entry Program header entry describing segment to be loaded.	314	* @param entry Program header entry describing segment to be loaded.
309	*	315	*
310	* @return EE_OK on success, error code otherwise.	316	* @return EE_OK on success, error code otherwise.
311	*/	317	*/
312	int load_segment(elf_ld_t elf, elf_segment_header_t entry)	318	int load_segment(elf_ld_t elf, elf_segment_header_t entry)
313	{	319	{
314	void *a;	320	void *a;
315	int flags = 0;	321	int flags = 0;
316	uintptr_t bias;	322	uintptr_t bias;
317	uintptr_t base;	323	uintptr_t base;
318	size_t mem_sz;	324	size_t mem_sz;
319	int rc;	325	int rc;
320		326
321	// printf("load segment at addr 0x%x, size 0x%x\n", entry->p_vaddr,	327	// printf("load segment at addr 0x%x, size 0x%x\n", entry->p_vaddr,
322	// entry->p_memsz);	328	// entry->p_memsz);
323		329
324	bias = elf->bias;	330	bias = elf->bias;
325		331
326	if (entry->p_align > 1) {	332	if (entry->p_align > 1) {
327	if ((entry->p_offset % entry->p_align) !=	333	if ((entry->p_offset % entry->p_align) !=
328	(entry->p_vaddr % entry->p_align)) {	334	(entry->p_vaddr % entry->p_align)) {
329	printf("align check 1 failed offset%%align=%d, vaddr%%align=%d\n",	335	printf("align check 1 failed offset%%align=%d, "
-		336	"vaddr%%align=%d\n",
330	entry->p_offset % entry->p_align,	337	entry->p_offset % entry->p_align,
331	entry->p_vaddr % entry->p_align	338	entry->p_vaddr % entry->p_align
332	);	339	);
333	return EE_INVALID;	340	return EE_INVALID;
334	}	341	}
335	}	342	}
336		343
337	/* Final flags that will be set for the memory area */	344	/* Final flags that will be set for the memory area */
338		345
339	if (entry->p_flags & PF_X)	346	if (entry->p_flags & PF_X)
340	flags \|= AS_AREA_EXEC;	347	flags \|= AS_AREA_EXEC;
341	if (entry->p_flags & PF_W)	348	if (entry->p_flags & PF_W)
342	flags \|= AS_AREA_WRITE;	349	flags \|= AS_AREA_WRITE;
343	if (entry->p_flags & PF_R)	350	if (entry->p_flags & PF_R)
344	flags \|= AS_AREA_READ;	351	flags \|= AS_AREA_READ;
345	flags \|= AS_AREA_CACHEABLE;	352	flags \|= AS_AREA_CACHEABLE;
346		353
347	base = ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE);	354	base = ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE);
348	mem_sz = entry->p_memsz + (entry->p_vaddr - base);	355	mem_sz = entry->p_memsz + (entry->p_vaddr - base);
349		356
350	// printf("map to p_vaddr=0x%x-0x%x...\n", entry->p_vaddr + bias,	357	// printf("map to p_vaddr=0x%x-0x%x...\n", entry->p_vaddr + bias,
351	// entry->p_vaddr + bias + ALIGN_UP(entry->p_memsz, PAGE_SIZE));	358	// entry->p_vaddr + bias + ALIGN_UP(entry->p_memsz, PAGE_SIZE));
352		359
353	/*	360	/*
354	* For the course of loading, the area needs to be readable	361	* For the course of loading, the area needs to be readable
355	* and writeable.	362	* and writeable.
356	*/	363	*/
357	a = as_area_create((uint8_t *)base + bias,	364	a = as_area_create((uint8_t *)base + bias,
358	mem_sz, AS_AREA_READ \| AS_AREA_WRITE \| AS_AREA_CACHEABLE);	365	mem_sz, AS_AREA_READ \| AS_AREA_WRITE \| AS_AREA_CACHEABLE);
359	if (a == (void *)(-1)) {	366	if (a == (void *)(-1)) {
360	printf("memory mapping failed\n");	367	printf("memory mapping failed\n");
361	return EE_MEMORY;	368	return EE_MEMORY;
362	}	369	}
363		370
364	// printf("as_area_create(0x%lx, 0x%x, %d) -> 0x%lx\n",	371	// printf("as_area_create(0x%lx, 0x%x, %d) -> 0x%lx\n",
365	// entry->p_vaddr+bias, entry->p_memsz, flags, (uintptr_t)a);	372	// entry->p_vaddr+bias, entry->p_memsz, flags, (uintptr_t)a);
366		373
367	/*	374	/*
368	* Load segment data	375	* Load segment data
369	*/	376	*/
370	// printf("seek to %d\n", entry->p_offset);	377	// printf("seek to %d\n", entry->p_offset);
371	rc = lseek(elf->fd, entry->p_offset, SEEK_SET);	378	rc = lseek(elf->fd, entry->p_offset, SEEK_SET);
-		379	if (rc < 0) {
372	if (rc < 0) { printf("seek error\n"); return EE_INVALID; }	380	printf("seek error\n");
-		381	return EE_INVALID;
-		382	}
373		383
374	// printf("read 0x%x bytes to address 0x%x\n", entry->p_filesz, entry->p_vaddr+bias);	384	// printf("read 0x%x bytes to address 0x%x\n", entry->p_filesz, entry->p_vaddr+bias);
375	/* rc = read(fd, (void *)(entry->p_vaddr + bias), entry->p_filesz);	385	/* rc = read(fd, (void *)(entry->p_vaddr + bias), entry->p_filesz);
376	if (rc < 0) { printf("read error\n"); return EE_INVALID; }*/	386	if (rc < 0) { printf("read error\n"); return EE_INVALID; }*/
377		387
378	/* Long reads are not possible yet. Load segment picewise */	388	/* Long reads are not possible yet. Load segment picewise */
379		389
380	unsigned left, now;	390	unsigned left, now;
381	uint8_t *dp;	391	uint8_t *dp;
382		392
383	left = entry->p_filesz;	393	left = entry->p_filesz;
384	dp = (uint8_t *)(entry->p_vaddr + bias);	394	dp = (uint8_t *)(entry->p_vaddr + bias);
385		395
386	while (left > 0) {	396	while (left > 0) {
387	now = 16384;	397	now = 16384;
388	if (now > left) now = left;	398	if (now > left) now = left;
389		399
390	// printf("read %d...", now);	400	// printf("read %d...", now);
391	rc = read(elf->fd, dp, now);	401	rc = read(elf->fd, dp, now);
392	// printf("->%d\n", rc);	402	// printf("->%d\n", rc);
393		403
-		404	if (rc < 0) {
394	if (rc < 0) { printf("read error\n"); return EE_INVALID; }	405	printf("read error\n");
-		406	return EE_INVALID;
-		407	}
395		408
396	left -= now;	409	left -= now;
397	dp += now;	410	dp += now;
398	}	411	}
399		412
400	// printf("set area flags to %d\n", flags);	413	// printf("set area flags to %d\n", flags);
401	rc = as_area_change_flags((uint8_t *)entry->p_vaddr + bias, flags);	414	rc = as_area_change_flags((uint8_t *)entry->p_vaddr + bias, flags);
402	if (rc != 0) {	415	if (rc != 0) {
403	printf("failed to set memory area flags\n");	416	printf("failed to set memory area flags\n");
404	return EE_MEMORY;	417	return EE_MEMORY;
405	}	418	}
406		419
407	if (flags & AS_AREA_EXEC) {	420	if (flags & AS_AREA_EXEC) {
408	/* Enforce SMC coherence for the segment */	421	/* Enforce SMC coherence for the segment */
409	if (smc_coherence(entry->p_vaddr + bias, entry->p_filesz))	422	if (smc_coherence(entry->p_vaddr + bias, entry->p_filesz))
410	return EE_MEMORY;	423	return EE_MEMORY;
411	}	424	}
412		425
413	return EE_OK;	426	return EE_OK;
414	}	427	}
415		428
416	/** Process section header.	429	/** Process section header.
417	*	430	*
418	* @param elf Loader state.	431	* @param elf Loader state.
419	* @param entry Segment header.	432	* @param entry Segment header.
420	*	433	*
421	* @return EE_OK on success, error code otherwise.	434	* @return EE_OK on success, error code otherwise.
422	*/	435	*/
423	static int section_header(elf_ld_t elf, elf_section_header_t entry)	436	static int section_header(elf_ld_t elf, elf_section_header_t entry)
424	{	437	{
425	switch (entry->sh_type) {	438	switch (entry->sh_type) {
426	case SHT_PROGBITS:	439	case SHT_PROGBITS:
427	if (entry->sh_flags & SHF_TLS) {	440	if (entry->sh_flags & SHF_TLS) {
428	/* .tdata */	441	/* .tdata */
429	}	442	}
430	break;	443	break;
431	case SHT_NOBITS:	444	case SHT_NOBITS:
432	if (entry->sh_flags & SHF_TLS) {	445	if (entry->sh_flags & SHF_TLS) {
433	/* .tbss */	446	/* .tbss */
434	}	447	}
435	break;	448	break;
436	case SHT_DYNAMIC:	449	case SHT_DYNAMIC:
437	/* Record pointer to dynamic section into info structure */	450	/* Record pointer to dynamic section into info structure */
438	elf->info->dynamic =	451	elf->info->dynamic =
439	(void )((uint8_t )entry->sh_addr + elf->bias);	452	(void )((uint8_t )entry->sh_addr + elf->bias);
440	printf("dynamic section found at 0x%x\n",	453	printf("dynamic section found at 0x%x\n",
441	(uintptr_t)elf->info->dynamic);	454	(uintptr_t)elf->info->dynamic);
442	break;	455	break;
443	default:	456	default:
444	break;	457	break;
445	}	458	}
446		459
447	return EE_OK;	460	return EE_OK;
448	}	461	}
449		462
450	/** @}	463	/** @}
451	*/	464	*/
452		465

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/loader/elf_load.c – Rev 3222 → 3223