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 <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);
 
/** Read until the buffer is read in its entirety. */
static int my_read(int fd, char *buf, size_t len)
{
    int cnt = 0;
    do {
        buf += cnt;
        len -= cnt;
        cnt = read(fd, buf, len);
    } while ((cnt > 0) && ((len - cnt) > 0));
 
    return cnt;
}
 
/** 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, eld_flags_t flags,
    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 (error %d)\n", fd);
        return -1;
    }
 
    elf.fd = fd;
    elf.info = info;
    elf.flags = flags;
 
    rc = elf_load(&elf, so_bias);
 
    close(fd);
 
    return rc;
}
 
/** 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;
    pcb->rtld_runtime = NULL;
}
 
 
/** 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 = my_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 = my_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 = my_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 == "/app/dload" */
        elf->info->interp = "/app/dload";
        break;
    case PT_DYNAMIC:
        /* Record pointer to dynamic section into info structure */
        elf->info->dynamic =
            (void *)((uint8_t *)entry->p_vaddr + elf->bias);
        printf("dynamic section found at 0x%x\n",
            (uintptr_t)elf->info->dynamic);
        break;
    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 = my_read(elf->fd, dp, now);
//      printf("->%d\n", rc);
 
        if (rc < 0) {
            printf("read error\n");
            return EE_INVALID;
        }
 
        left -= now;
        dp += now;
    }
 
    /*
     * The caller wants to modify the segments first. He will then
     * need to set the right access mode and ensure SMC coherence.
     */
    if ((elf->flags & ELDF_RW) != 0) return EE_OK;
 
//  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:
 
 
 
 
 
        break;
    default:
        break;
    }
   
    return EE_OK;
}
 
/** @}
 */
 

Rev 3686	Rev 3690
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	/** Read until the buffer is read in its entirety. */	74	/** Read until the buffer is read in its entirety. */
75	static int my_read(int fd, char *buf, size_t len)	75	static int my_read(int fd, char *buf, size_t len)
76	{	76	{
77	int cnt = 0;	77	int cnt = 0;
78	do {	78	do {
79	buf += cnt;	79	buf += cnt;
80	len -= cnt;	80	len -= cnt;
81	cnt = read(fd, buf, len);	81	cnt = read(fd, buf, len);
82	} while ((cnt > 0) && ((len - cnt) > 0));	82	} while ((cnt > 0) && ((len - cnt) > 0));
83		83
84	return cnt;	84	return cnt;
85	}	85	}
86		86
87	/** Load ELF binary from a file.	87	/** Load ELF binary from a file.
88	*	88	*
89	* Load an ELF binary from the specified file. If the file is	89	* Load an ELF binary from the specified file. If the file is
90	* an executable program, it is loaded unbiased. If it is a shared	90	* an executable program, it is loaded unbiased. If it is a shared
91	* object, it is loaded with the bias @a so_bias. Some information	91	* object, it is loaded with the bias @a so_bias. Some information
92	* extracted from the binary is stored in a elf_info_t structure	92	* extracted from the binary is stored in a elf_info_t structure
93	* pointed to by @a info.	93	* pointed to by @a info.
94	*	94	*
95	* @param file_name Path to the ELF file.	95	* @param file_name Path to the ELF file.
96	* @param so_bias Bias to use if the file is a shared object.	96	* @param so_bias Bias to use if the file is a shared object.
97	* @param info Pointer to a structure for storing information	97	* @param info Pointer to a structure for storing information
98	* extracted from the binary.	98	* extracted from the binary.
99	*	99	*
100	* @return EOK on success or negative error code.	100	* @return EOK on success or negative error code.
101	*/	101	*/
102	int elf_load_file(char *file_name, size_t so_bias, eld_flags_t flags,	102	int elf_load_file(char *file_name, size_t so_bias, eld_flags_t flags,
103	elf_info_t *info)	103	elf_info_t *info)
104	{	104	{
105	elf_ld_t elf;	105	elf_ld_t elf;
106		106
107	int fd;	107	int fd;
108	int rc;	108	int rc;
109		109
110	// printf("open and read '%s'...\n", file_name);	110	// printf("open and read '%s'...\n", file_name);
111		111
112	fd = open(file_name, O_RDONLY);	112	fd = open(file_name, O_RDONLY);
113	if (fd < 0) {	113	if (fd < 0) {
114	printf("failed opening file (error %d)\n", fd);	114	printf("failed opening file (error %d)\n", fd);
115	return -1;	115	return -1;
116	}	116	}
117		117
118	elf.fd = fd;	118	elf.fd = fd;
119	elf.info = info;	119	elf.info = info;
120	elf.flags = flags;	120	elf.flags = flags;
121		121
122	rc = elf_load(&elf, so_bias);	122	rc = elf_load(&elf, so_bias);
123		123
124	close(fd);	124	close(fd);
125		125
126	return rc;	126	return rc;
127	}	127	}
128		128
129	/** Create the program control block (PCB).	129	/** Create the program control block (PCB).
130	*	130	*
131	* Fills the program control block @a pcb with information from	131	* Fills the program control block @a pcb with information from
132	* @a info.	132	* @a info.
133	*	133	*
134	* @param info Program info structure	134	* @param info Program info structure
135	* @return EOK on success or negative error code	135	* @return EOK on success or negative error code
136	*/	136	*/
137	void elf_create_pcb(elf_info_t info, pcb_t pcb)	137	void elf_create_pcb(elf_info_t info, pcb_t pcb)
138	{	138	{
139	pcb->entry = info->entry;	139	pcb->entry = info->entry;
140	pcb->dynamic = info->dynamic;	140	pcb->dynamic = info->dynamic;
141	pcb->rtld_runtime = NULL;	141	pcb->rtld_runtime = NULL;
142	}	142	}
143		143
144		144
145	/** Load an ELF binary.	145	/** Load an ELF binary.
146	*	146	*
147	* The @a elf structure contains the loader state, including	147	* The @a elf structure contains the loader state, including
148	* an open file, from which the binary will be loaded,	148	* an open file, from which the binary will be loaded,
149	* a pointer to the @c info structure etc.	149	* a pointer to the @c info structure etc.
150	*	150	*
151	* @param elf Pointer to loader state buffer.	151	* @param elf Pointer to loader state buffer.
152	* @param so_bias Bias to use if the file is a shared object.	152	* @param so_bias Bias to use if the file is a shared object.
153	* @return EE_OK on success or EE_xx error code.	153	* @return EE_OK on success or EE_xx error code.
154	*/	154	*/
155	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias)	155	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias)
156	{	156	{
157	elf_header_t header_buf;	157	elf_header_t header_buf;
158	elf_header_t *header = &header_buf;	158	elf_header_t *header = &header_buf;
159	int i, rc;	159	int i, rc;
160		160
161	rc = my_read(elf->fd, header, sizeof(elf_header_t));	161	rc = my_read(elf->fd, header, sizeof(elf_header_t));
162	if (rc < 0) {	162	if (rc < 0) {
163	printf("read error\n");	163	printf("read error\n");
164	return EE_INVALID;	164	return EE_INVALID;
165	}	165	}
166		166
167	elf->header = header;	167	elf->header = header;
168		168
169	// printf("ELF-load:");	169	// printf("ELF-load:");
170	/* Identify ELF */	170	/* Identify ELF */
171	if (header->e_ident[EI_MAG0] != ELFMAG0 \|\|	171	if (header->e_ident[EI_MAG0] != ELFMAG0 \|\|
172	header->e_ident[EI_MAG1] != ELFMAG1 \|\|	172	header->e_ident[EI_MAG1] != ELFMAG1 \|\|
173	header->e_ident[EI_MAG2] != ELFMAG2 \|\|	173	header->e_ident[EI_MAG2] != ELFMAG2 \|\|
174	header->e_ident[EI_MAG3] != ELFMAG3) {	174	header->e_ident[EI_MAG3] != ELFMAG3) {
175	printf("invalid header\n");	175	printf("invalid header\n");
176	return EE_INVALID;	176	return EE_INVALID;
177	}	177	}
178		178
179	/* Identify ELF compatibility */	179	/* Identify ELF compatibility */
180	if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING \|\|	180	if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING \|\|
181	header->e_machine != ELF_MACHINE \|\|	181	header->e_machine != ELF_MACHINE \|\|
182	header->e_ident[EI_VERSION] != EV_CURRENT \|\|	182	header->e_ident[EI_VERSION] != EV_CURRENT \|\|
183	header->e_version != EV_CURRENT \|\|	183	header->e_version != EV_CURRENT \|\|
184	header->e_ident[EI_CLASS] != ELF_CLASS) {	184	header->e_ident[EI_CLASS] != ELF_CLASS) {
185	printf("incompatible data/version/class\n");	185	printf("incompatible data/version/class\n");
186	return EE_INCOMPATIBLE;	186	return EE_INCOMPATIBLE;
187	}	187	}
188		188
189	if (header->e_phentsize != sizeof(elf_segment_header_t)) {	189	if (header->e_phentsize != sizeof(elf_segment_header_t)) {
190	printf("e_phentsize:%d != %d\n", header->e_phentsize,	190	printf("e_phentsize:%d != %d\n", header->e_phentsize,
191	sizeof(elf_segment_header_t));	191	sizeof(elf_segment_header_t));
192	return EE_INCOMPATIBLE;	192	return EE_INCOMPATIBLE;
193	}	193	}
194		194
195	if (header->e_shentsize != sizeof(elf_section_header_t)) {	195	if (header->e_shentsize != sizeof(elf_section_header_t)) {
196	printf("e_shentsize:%d != %d\n", header->e_shentsize,	196	printf("e_shentsize:%d != %d\n", header->e_shentsize,
197	sizeof(elf_section_header_t));	197	sizeof(elf_section_header_t));
198	return EE_INCOMPATIBLE;	198	return EE_INCOMPATIBLE;
199	}	199	}
200		200
201	/* Check if the object type is supported. */	201	/* Check if the object type is supported. */
202	if (header->e_type != ET_EXEC && header->e_type != ET_DYN) {	202	if (header->e_type != ET_EXEC && header->e_type != ET_DYN) {
203	printf("Object type %d is not supported\n", header->e_type);	203	printf("Object type %d is not supported\n", header->e_type);
204	return EE_UNSUPPORTED;	204	return EE_UNSUPPORTED;
205	}	205	}
206		206
207	/* Shared objects can be loaded with a bias */	207	/* Shared objects can be loaded with a bias */
208	// printf("Object type: %d\n", header->e_type);	208	// printf("Object type: %d\n", header->e_type);
209	if (header->e_type == ET_DYN)	209	if (header->e_type == ET_DYN)
210	elf->bias = so_bias;	210	elf->bias = so_bias;
211	else	211	else
212	elf->bias = 0;	212	elf->bias = 0;
213		213
214	// printf("Bias set to 0x%x\n", elf->bias);	214	// printf("Bias set to 0x%x\n", elf->bias);
215	elf->info->interp = NULL;	215	elf->info->interp = NULL;
216	elf->info->dynamic = NULL;	216	elf->info->dynamic = NULL;
217		217
218	// printf("parse segments\n");	218	// printf("parse segments\n");
219		219
220	/* Walk through all segment headers and process them. */	220	/* Walk through all segment headers and process them. */
221	for (i = 0; i < header->e_phnum; i++) {	221	for (i = 0; i < header->e_phnum; i++) {
222	elf_segment_header_t segment_hdr;	222	elf_segment_header_t segment_hdr;
223		223
224	/* Seek to start of segment header */	224	/* Seek to start of segment header */
225	lseek(elf->fd, header->e_phoff	225	lseek(elf->fd, header->e_phoff
226	+ i * sizeof(elf_segment_header_t), SEEK_SET);	226	+ i * sizeof(elf_segment_header_t), SEEK_SET);
227		227
228	rc = my_read(elf->fd, &segment_hdr,	228	rc = my_read(elf->fd, &segment_hdr,
229	sizeof(elf_segment_header_t));	229	sizeof(elf_segment_header_t));
230	if (rc < 0) {	230	if (rc < 0) {
231	printf("read error\n");	231	printf("read error\n");
232	return EE_INVALID;	232	return EE_INVALID;
233	}	233	}
234		234
235	rc = segment_header(elf, &segment_hdr);	235	rc = segment_header(elf, &segment_hdr);
236	if (rc != EE_OK)	236	if (rc != EE_OK)
237	return rc;	237	return rc;
238	}	238	}
239		239
240	// printf("parse sections\n");	240	// printf("parse sections\n");
241		241
242	/* Inspect all section headers and proccess them. */	242	/* Inspect all section headers and proccess them. */
243	for (i = 0; i < header->e_shnum; i++) {	243	for (i = 0; i < header->e_shnum; i++) {
244	elf_section_header_t section_hdr;	244	elf_section_header_t section_hdr;
245		245
246	/* Seek to start of section header */	246	/* Seek to start of section header */
247	lseek(elf->fd, header->e_shoff	247	lseek(elf->fd, header->e_shoff
248	+ i * sizeof(elf_section_header_t), SEEK_SET);	248	+ i * sizeof(elf_section_header_t), SEEK_SET);
249		249
250	rc = my_read(elf->fd, &section_hdr,	250	rc = my_read(elf->fd, &section_hdr,
251	sizeof(elf_section_header_t));	251	sizeof(elf_section_header_t));
252	if (rc < 0) {	252	if (rc < 0) {
253	printf("read error\n");	253	printf("read error\n");
254	return EE_INVALID;	254	return EE_INVALID;
255	}	255	}
256		256
257	rc = section_header(elf, &section_hdr);	257	rc = section_header(elf, &section_hdr);
258	if (rc != EE_OK)	258	if (rc != EE_OK)
259	return rc;	259	return rc;
260	}	260	}
261		261
262	elf->info->entry =	262	elf->info->entry =
263	(entry_point_t)((uint8_t *)header->e_entry + elf->bias);	263	(entry_point_t)((uint8_t *)header->e_entry + elf->bias);
264		264
265	// printf("done\n");	265	// printf("done\n");
266		266
267	return EE_OK;	267	return EE_OK;
268	}	268	}
269		269
270	/** Print error message according to error code.	270	/** Print error message according to error code.
271	*	271	*
272	* @param rc Return code returned by elf_load().	272	* @param rc Return code returned by elf_load().
273	*	273	*
274	* @return NULL terminated description of error.	274	* @return NULL terminated description of error.
275	*/	275	*/
276	char *elf_error(unsigned int rc)	276	char *elf_error(unsigned int rc)
277	{	277	{
278	assert(rc < sizeof(error_codes) / sizeof(char *));	278	assert(rc < sizeof(error_codes) / sizeof(char *));
279		279
280	return error_codes[rc];	280	return error_codes[rc];
281	}	281	}
282		282
283	/** Process segment header.	283	/** Process segment header.
284	*	284	*
285	* @param entry Segment header.	285	* @param entry Segment header.
286	*	286	*
287	* @return EE_OK on success, error code otherwise.	287	* @return EE_OK on success, error code otherwise.
288	*/	288	*/
289	static int segment_header(elf_ld_t elf, elf_segment_header_t entry)	289	static int segment_header(elf_ld_t elf, elf_segment_header_t entry)
290	{	290	{
291	switch (entry->p_type) {	291	switch (entry->p_type) {
292	case PT_NULL:	292	case PT_NULL:
293	case PT_PHDR:	293	case PT_PHDR:
294	break;	294	break;
295	case PT_LOAD:	295	case PT_LOAD:
296	return load_segment(elf, entry);	296	return load_segment(elf, entry);
297	break;	297	break;
298	case PT_INTERP:	298	case PT_INTERP:
299	/* Assume silently interp == "/app/dload" */	299	/* Assume silently interp == "/app/dload" */
300	elf->info->interp = "/app/dload";	300	elf->info->interp = "/app/dload";
301	break;	301	break;
302	case PT_DYNAMIC:	302	case PT_DYNAMIC:
-		303	/* Record pointer to dynamic section into info structure */
-		304	elf->info->dynamic =
-		305	(void )((uint8_t )entry->p_vaddr + elf->bias);
-		306	printf("dynamic section found at 0x%x\n",
-		307	(uintptr_t)elf->info->dynamic);
-		308	break;
303	case PT_SHLIB:	309	case PT_SHLIB:
304	case PT_NOTE:	310	case PT_NOTE:
305	case PT_LOPROC:	311	case PT_LOPROC:
306	case PT_HIPROC:	312	case PT_HIPROC:
307	default:	313	default:
308	printf("segment p_type %d unknown\n", entry->p_type);	314	printf("segment p_type %d unknown\n", entry->p_type);
309	return EE_UNSUPPORTED;	315	return EE_UNSUPPORTED;
310	break;	316	break;
311	}	317	}
312	return EE_OK;	318	return EE_OK;
313	}	319	}
314		320
315	/** Load segment described by program header entry.	321	/** Load segment described by program header entry.
316	*	322	*
317	* @param elf Loader state.	323	* @param elf Loader state.
318	* @param entry Program header entry describing segment to be loaded.	324	* @param entry Program header entry describing segment to be loaded.
319	*	325	*
320	* @return EE_OK on success, error code otherwise.	326	* @return EE_OK on success, error code otherwise.
321	*/	327	*/
322	int load_segment(elf_ld_t elf, elf_segment_header_t entry)	328	int load_segment(elf_ld_t elf, elf_segment_header_t entry)
323	{	329	{
324	void *a;	330	void *a;
325	int flags = 0;	331	int flags = 0;
326	uintptr_t bias;	332	uintptr_t bias;
327	uintptr_t base;	333	uintptr_t base;
328	size_t mem_sz;	334	size_t mem_sz;
329	int rc;	335	int rc;
330		336
331	// printf("load segment at addr 0x%x, size 0x%x\n", entry->p_vaddr,	337	// printf("load segment at addr 0x%x, size 0x%x\n", entry->p_vaddr,
332	// entry->p_memsz);	338	// entry->p_memsz);
333		339
334	bias = elf->bias;	340	bias = elf->bias;
335		341
336	if (entry->p_align > 1) {	342	if (entry->p_align > 1) {
337	if ((entry->p_offset % entry->p_align) !=	343	if ((entry->p_offset % entry->p_align) !=
338	(entry->p_vaddr % entry->p_align)) {	344	(entry->p_vaddr % entry->p_align)) {
339	printf("align check 1 failed offset%%align=%d, "	345	printf("align check 1 failed offset%%align=%d, "
340	"vaddr%%align=%d\n",	346	"vaddr%%align=%d\n",
341	entry->p_offset % entry->p_align,	347	entry->p_offset % entry->p_align,
342	entry->p_vaddr % entry->p_align	348	entry->p_vaddr % entry->p_align
343	);	349	);
344	return EE_INVALID;	350	return EE_INVALID;
345	}	351	}
346	}	352	}
347		353
348	/* Final flags that will be set for the memory area */	354	/* Final flags that will be set for the memory area */
349		355
350	if (entry->p_flags & PF_X)	356	if (entry->p_flags & PF_X)
351	flags \|= AS_AREA_EXEC;	357	flags \|= AS_AREA_EXEC;
352	if (entry->p_flags & PF_W)	358	if (entry->p_flags & PF_W)
353	flags \|= AS_AREA_WRITE;	359	flags \|= AS_AREA_WRITE;
354	if (entry->p_flags & PF_R)	360	if (entry->p_flags & PF_R)
355	flags \|= AS_AREA_READ;	361	flags \|= AS_AREA_READ;
356	flags \|= AS_AREA_CACHEABLE;	362	flags \|= AS_AREA_CACHEABLE;
357		363
358	base = ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE);	364	base = ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE);
359	mem_sz = entry->p_memsz + (entry->p_vaddr - base);	365	mem_sz = entry->p_memsz + (entry->p_vaddr - base);
360		366
361	// printf("map to p_vaddr=0x%x-0x%x...\n", entry->p_vaddr + bias,	367	// printf("map to p_vaddr=0x%x-0x%x...\n", entry->p_vaddr + bias,
362	// entry->p_vaddr + bias + ALIGN_UP(entry->p_memsz, PAGE_SIZE));	368	// entry->p_vaddr + bias + ALIGN_UP(entry->p_memsz, PAGE_SIZE));
363		369
364	/*	370	/*
365	* For the course of loading, the area needs to be readable	371	* For the course of loading, the area needs to be readable
366	* and writeable.	372	* and writeable.
367	*/	373	*/
368	a = as_area_create((uint8_t *)base + bias, mem_sz,	374	a = as_area_create((uint8_t *)base + bias, mem_sz,
369	AS_AREA_READ \| AS_AREA_WRITE \| AS_AREA_CACHEABLE);	375	AS_AREA_READ \| AS_AREA_WRITE \| AS_AREA_CACHEABLE);
370	if (a == (void *)(-1)) {	376	if (a == (void *)(-1)) {
371	printf("memory mapping failed\n");	377	printf("memory mapping failed\n");
372	return EE_MEMORY;	378	return EE_MEMORY;
373	}	379	}
374		380
375	// printf("as_area_create(0x%lx, 0x%x, %d) -> 0x%lx\n",	381	// printf("as_area_create(0x%lx, 0x%x, %d) -> 0x%lx\n",
376	// entry->p_vaddr+bias, entry->p_memsz, flags, (uintptr_t)a);	382	// entry->p_vaddr+bias, entry->p_memsz, flags, (uintptr_t)a);
377		383
378	/*	384	/*
379	* Load segment data	385	* Load segment data
380	*/	386	*/
381	// printf("seek to %d\n", entry->p_offset);	387	// printf("seek to %d\n", entry->p_offset);
382	rc = lseek(elf->fd, entry->p_offset, SEEK_SET);	388	rc = lseek(elf->fd, entry->p_offset, SEEK_SET);
383	if (rc < 0) {	389	if (rc < 0) {
384	printf("seek error\n");	390	printf("seek error\n");
385	return EE_INVALID;	391	return EE_INVALID;
386	}	392	}
387		393
388	// printf("read 0x%x bytes to address 0x%x\n", entry->p_filesz, entry->p_vaddr+bias);	394	// printf("read 0x%x bytes to address 0x%x\n", entry->p_filesz, entry->p_vaddr+bias);
389	/* rc = read(fd, (void *)(entry->p_vaddr + bias), entry->p_filesz);	395	/* rc = read(fd, (void *)(entry->p_vaddr + bias), entry->p_filesz);
390	if (rc < 0) { printf("read error\n"); return EE_INVALID; }*/	396	if (rc < 0) { printf("read error\n"); return EE_INVALID; }*/
391		397
392	/* Long reads are not possible yet. Load segment picewise */	398	/* Long reads are not possible yet. Load segment picewise */
393		399
394	unsigned left, now;	400	unsigned left, now;
395	uint8_t *dp;	401	uint8_t *dp;
396		402
397	left = entry->p_filesz;	403	left = entry->p_filesz;
398	dp = (uint8_t *)(entry->p_vaddr + bias);	404	dp = (uint8_t *)(entry->p_vaddr + bias);
399		405
400	while (left > 0) {	406	while (left > 0) {
401	now = 16384;	407	now = 16384;
402	if (now > left) now = left;	408	if (now > left) now = left;
403		409
404	// printf("read %d...", now);	410	// printf("read %d...", now);
405	rc = my_read(elf->fd, dp, now);	411	rc = my_read(elf->fd, dp, now);
406	// printf("->%d\n", rc);	412	// printf("->%d\n", rc);
407		413
408	if (rc < 0) {	414	if (rc < 0) {
409	printf("read error\n");	415	printf("read error\n");
410	return EE_INVALID;	416	return EE_INVALID;
411	}	417	}
412		418
413	left -= now;	419	left -= now;
414	dp += now;	420	dp += now;
415	}	421	}
416		422
417	/*	423	/*
418	* The caller wants to modify the segments first. He will then	424	* The caller wants to modify the segments first. He will then
419	* need to set the right access mode and ensure SMC coherence.	425	* need to set the right access mode and ensure SMC coherence.
420	*/	426	*/
421	if ((elf->flags & ELDF_RW) != 0) return EE_OK;	427	if ((elf->flags & ELDF_RW) != 0) return EE_OK;
422		428
423	// printf("set area flags to %d\n", flags);	429	// printf("set area flags to %d\n", flags);
424	rc = as_area_change_flags((uint8_t *)entry->p_vaddr + bias, flags);	430	rc = as_area_change_flags((uint8_t *)entry->p_vaddr + bias, flags);
425	if (rc != 0) {	431	if (rc != 0) {
426	printf("failed to set memory area flags\n");	432	printf("failed to set memory area flags\n");
427	return EE_MEMORY;	433	return EE_MEMORY;
428	}	434	}
429		435
430	if (flags & AS_AREA_EXEC) {	436	if (flags & AS_AREA_EXEC) {
431	/* Enforce SMC coherence for the segment */	437	/* Enforce SMC coherence for the segment */
432	if (smc_coherence(entry->p_vaddr + bias, entry->p_filesz))	438	if (smc_coherence(entry->p_vaddr + bias, entry->p_filesz))
433	return EE_MEMORY;	439	return EE_MEMORY;
434	}	440	}
435		441
436	return EE_OK;	442	return EE_OK;
437	}	443	}
438		444
439	/** Process section header.	445	/** Process section header.
440	*	446	*
441	* @param elf Loader state.	447	* @param elf Loader state.
442	* @param entry Segment header.	448	* @param entry Segment header.
443	*	449	*
444	* @return EE_OK on success, error code otherwise.	450	* @return EE_OK on success, error code otherwise.
445	*/	451	*/
446	static int section_header(elf_ld_t elf, elf_section_header_t entry)	452	static int section_header(elf_ld_t elf, elf_section_header_t entry)
447	{	453	{
448	switch (entry->sh_type) {	454	switch (entry->sh_type) {
449	case SHT_PROGBITS:	455	case SHT_PROGBITS:
450	if (entry->sh_flags & SHF_TLS) {	456	if (entry->sh_flags & SHF_TLS) {
451	/* .tdata */	457	/* .tdata */
452	}	458	}
453	break;	459	break;
454	case SHT_NOBITS:	460	case SHT_NOBITS:
455	if (entry->sh_flags & SHF_TLS) {	461	if (entry->sh_flags & SHF_TLS) {
456	/* .tbss */	462	/* .tbss */
457	}	463	}
458	break;	464	break;
459	case SHT_DYNAMIC:	465	case SHT_DYNAMIC:
460	/* Record pointer to dynamic section into info structure */	-
461	elf->info->dynamic =	-
462	(void )((uint8_t )entry->sh_addr + elf->bias);	-
463	printf("dynamic section found at 0x%x\n",	-
464	(uintptr_t)elf->info->dynamic);	-
465	break;	466	break;
466	default:	467	default:
467	break;	468	break;
468	}	469	}
469		470
470	return EE_OK;	471	return EE_OK;
471	}	472	}
472		473
473	/** @}	474	/** @}
474	*/	475	*/
475		476

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(root)/branches/dynload/uspace/srv/loader/elf_load.c – Rev 3686 → 3690