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;
}
 
 
/** 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:
    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:
        /* 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 3562	Rev 3681
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	/** Run an ELF executable.	-
130	*	-
131	* Transfers control to the entry point of an ELF executable loaded	-
132	* earlier with elf_load_file(). This function does not return.	-
133	*	-
134	* @param info Info structure filled earlier by elf_load_file()	-
135	*/	-
136	void elf_run(elf_info_t info, pcb_t pcb)	-
137	{	-
138	program_run(info->entry, pcb);	-
139		-
140	/* not reached */	-
141	}	-
142		-
143	/** Create the program control block (PCB).	129	/** Create the program control block (PCB).
144	*	130	*
145	* Fills the program control block @a pcb with information from	131	* Fills the program control block @a pcb with information from
146	* @a info.	132	* @a info.
147	*	133	*
148	* @param info Program info structure	134	* @param info Program info structure
149	* @return EOK on success or negative error code	135	* @return EOK on success or negative error code
150	*/	136	*/
151	void elf_create_pcb(elf_info_t info, pcb_t pcb)	137	void elf_create_pcb(elf_info_t info, pcb_t pcb)
152	{	138	{
153	pcb->entry = info->entry;	139	pcb->entry = info->entry;
154	pcb->dynamic = info->dynamic;	140	pcb->dynamic = info->dynamic;
155	}	141	}
156		142
157		143
158	/** Load an ELF binary.	144	/** Load an ELF binary.
159	*	145	*
160	* The @a elf structure contains the loader state, including	146	* The @a elf structure contains the loader state, including
161	* an open file, from which the binary will be loaded,	147	* an open file, from which the binary will be loaded,
162	* a pointer to the @c info structure etc.	148	* a pointer to the @c info structure etc.
163	*	149	*
164	* @param elf Pointer to loader state buffer.	150	* @param elf Pointer to loader state buffer.
165	* @param so_bias Bias to use if the file is a shared object.	151	* @param so_bias Bias to use if the file is a shared object.
166	* @return EE_OK on success or EE_xx error code.	152	* @return EE_OK on success or EE_xx error code.
167	*/	153	*/
168	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias)	154	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias)
169	{	155	{
170	elf_header_t header_buf;	156	elf_header_t header_buf;
171	elf_header_t *header = &header_buf;	157	elf_header_t *header = &header_buf;
172	int i, rc;	158	int i, rc;
173		159
174	rc = my_read(elf->fd, header, sizeof(elf_header_t));	160	rc = my_read(elf->fd, header, sizeof(elf_header_t));
175	if (rc < 0) {	161	if (rc < 0) {
176	printf("read error\n");	162	printf("read error\n");
177	return EE_INVALID;	163	return EE_INVALID;
178	}	164	}
179		165
180	elf->header = header;	166	elf->header = header;
181		167
182	// printf("ELF-load:");	168	// printf("ELF-load:");
183	/* Identify ELF */	169	/* Identify ELF */
184	if (header->e_ident[EI_MAG0] != ELFMAG0 \|\|	170	if (header->e_ident[EI_MAG0] != ELFMAG0 \|\|
185	header->e_ident[EI_MAG1] != ELFMAG1 \|\|	171	header->e_ident[EI_MAG1] != ELFMAG1 \|\|
186	header->e_ident[EI_MAG2] != ELFMAG2 \|\|	172	header->e_ident[EI_MAG2] != ELFMAG2 \|\|
187	header->e_ident[EI_MAG3] != ELFMAG3) {	173	header->e_ident[EI_MAG3] != ELFMAG3) {
188	printf("invalid header\n");	174	printf("invalid header\n");
189	return EE_INVALID;	175	return EE_INVALID;
190	}	176	}
191		177
192	/* Identify ELF compatibility */	178	/* Identify ELF compatibility */
193	if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING \|\|	179	if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING \|\|
194	header->e_machine != ELF_MACHINE \|\|	180	header->e_machine != ELF_MACHINE \|\|
195	header->e_ident[EI_VERSION] != EV_CURRENT \|\|	181	header->e_ident[EI_VERSION] != EV_CURRENT \|\|
196	header->e_version != EV_CURRENT \|\|	182	header->e_version != EV_CURRENT \|\|
197	header->e_ident[EI_CLASS] != ELF_CLASS) {	183	header->e_ident[EI_CLASS] != ELF_CLASS) {
198	printf("incompatible data/version/class\n");	184	printf("incompatible data/version/class\n");
199	return EE_INCOMPATIBLE;	185	return EE_INCOMPATIBLE;
200	}	186	}
201		187
202	if (header->e_phentsize != sizeof(elf_segment_header_t)) {	188	if (header->e_phentsize != sizeof(elf_segment_header_t)) {
203	printf("e_phentsize:%d != %d\n", header->e_phentsize,	189	printf("e_phentsize:%d != %d\n", header->e_phentsize,
204	sizeof(elf_segment_header_t));	190	sizeof(elf_segment_header_t));
205	return EE_INCOMPATIBLE;	191	return EE_INCOMPATIBLE;
206	}	192	}
207		193
208	if (header->e_shentsize != sizeof(elf_section_header_t)) {	194	if (header->e_shentsize != sizeof(elf_section_header_t)) {
209	printf("e_shentsize:%d != %d\n", header->e_shentsize,	195	printf("e_shentsize:%d != %d\n", header->e_shentsize,
210	sizeof(elf_section_header_t));	196	sizeof(elf_section_header_t));
211	return EE_INCOMPATIBLE;	197	return EE_INCOMPATIBLE;
212	}	198	}
213		199
214	/* Check if the object type is supported. */	200	/* Check if the object type is supported. */
215	if (header->e_type != ET_EXEC && header->e_type != ET_DYN) {	201	if (header->e_type != ET_EXEC && header->e_type != ET_DYN) {
216	printf("Object type %d is not supported\n", header->e_type);	202	printf("Object type %d is not supported\n", header->e_type);
217	return EE_UNSUPPORTED;	203	return EE_UNSUPPORTED;
218	}	204	}
219		205
220	/* Shared objects can be loaded with a bias */	206	/* Shared objects can be loaded with a bias */
221	// printf("Object type: %d\n", header->e_type);	207	// printf("Object type: %d\n", header->e_type);
222	if (header->e_type == ET_DYN)	208	if (header->e_type == ET_DYN)
223	elf->bias = so_bias;	209	elf->bias = so_bias;
224	else	210	else
225	elf->bias = 0;	211	elf->bias = 0;
226		212
227	// printf("Bias set to 0x%x\n", elf->bias);	213	// printf("Bias set to 0x%x\n", elf->bias);
228	elf->info->interp = NULL;	214	elf->info->interp = NULL;
229	elf->info->dynamic = NULL;	215	elf->info->dynamic = NULL;
230		216
231	// printf("parse segments\n");	217	// printf("parse segments\n");
232		218
233	/* Walk through all segment headers and process them. */	219	/* Walk through all segment headers and process them. */
234	for (i = 0; i < header->e_phnum; i++) {	220	for (i = 0; i < header->e_phnum; i++) {
235	elf_segment_header_t segment_hdr;	221	elf_segment_header_t segment_hdr;
236		222
237	/* Seek to start of segment header */	223	/* Seek to start of segment header */
238	lseek(elf->fd, header->e_phoff	224	lseek(elf->fd, header->e_phoff
239	+ i * sizeof(elf_segment_header_t), SEEK_SET);	225	+ i * sizeof(elf_segment_header_t), SEEK_SET);
240		226
241	rc = my_read(elf->fd, &segment_hdr,	227	rc = my_read(elf->fd, &segment_hdr,
242	sizeof(elf_segment_header_t));	228	sizeof(elf_segment_header_t));
243	if (rc < 0) {	229	if (rc < 0) {
244	printf("read error\n");	230	printf("read error\n");
245	return EE_INVALID;	231	return EE_INVALID;
246	}	232	}
247		233
248	rc = segment_header(elf, &segment_hdr);	234	rc = segment_header(elf, &segment_hdr);
249	if (rc != EE_OK)	235	if (rc != EE_OK)
250	return rc;	236	return rc;
251	}	237	}
252		238
253	// printf("parse sections\n");	239	// printf("parse sections\n");
254		240
255	/* Inspect all section headers and proccess them. */	241	/* Inspect all section headers and proccess them. */
256	for (i = 0; i < header->e_shnum; i++) {	242	for (i = 0; i < header->e_shnum; i++) {
257	elf_section_header_t section_hdr;	243	elf_section_header_t section_hdr;
258		244
259	/* Seek to start of section header */	245	/* Seek to start of section header */
260	lseek(elf->fd, header->e_shoff	246	lseek(elf->fd, header->e_shoff
261	+ i * sizeof(elf_section_header_t), SEEK_SET);	247	+ i * sizeof(elf_section_header_t), SEEK_SET);
262		248
263	rc = my_read(elf->fd, &section_hdr,	249	rc = my_read(elf->fd, &section_hdr,
264	sizeof(elf_section_header_t));	250	sizeof(elf_section_header_t));
265	if (rc < 0) {	251	if (rc < 0) {
266	printf("read error\n");	252	printf("read error\n");
267	return EE_INVALID;	253	return EE_INVALID;
268	}	254	}
269		255
270	rc = section_header(elf, &section_hdr);	256	rc = section_header(elf, &section_hdr);
271	if (rc != EE_OK)	257	if (rc != EE_OK)
272	return rc;	258	return rc;
273	}	259	}
274		260
275	elf->info->entry =	261	elf->info->entry =
276	(entry_point_t)((uint8_t *)header->e_entry + elf->bias);	262	(entry_point_t)((uint8_t *)header->e_entry + elf->bias);
277		263
278	// printf("done\n");	264	// printf("done\n");
279		265
280	return EE_OK;	266	return EE_OK;
281	}	267	}
282		268
283	/** Print error message according to error code.	269	/** Print error message according to error code.
284	*	270	*
285	* @param rc Return code returned by elf_load().	271	* @param rc Return code returned by elf_load().
286	*	272	*
287	* @return NULL terminated description of error.	273	* @return NULL terminated description of error.
288	*/	274	*/
289	char *elf_error(unsigned int rc)	275	char *elf_error(unsigned int rc)
290	{	276	{
291	assert(rc < sizeof(error_codes) / sizeof(char *));	277	assert(rc < sizeof(error_codes) / sizeof(char *));
292		278
293	return error_codes[rc];	279	return error_codes[rc];
294	}	280	}
295		281
296	/** Process segment header.	282	/** Process segment header.
297	*	283	*
298	* @param entry Segment header.	284	* @param entry Segment header.
299	*	285	*
300	* @return EE_OK on success, error code otherwise.	286	* @return EE_OK on success, error code otherwise.
301	*/	287	*/
302	static int segment_header(elf_ld_t elf, elf_segment_header_t entry)	288	static int segment_header(elf_ld_t elf, elf_segment_header_t entry)
303	{	289	{
304	switch (entry->p_type) {	290	switch (entry->p_type) {
305	case PT_NULL:	291	case PT_NULL:
306	case PT_PHDR:	292	case PT_PHDR:
307	break;	293	break;
308	case PT_LOAD:	294	case PT_LOAD:
309	return load_segment(elf, entry);	295	return load_segment(elf, entry);
310	break;	296	break;
311	case PT_INTERP:	297	case PT_INTERP:
312	/* Assume silently interp == "/lib/rtld" */	298	/* Assume silently interp == "/app/dload" */
313	elf->info->interp = "/lib/rtld";	299	elf->info->interp = "/app/dload";
314	break;	300	break;
315	case PT_DYNAMIC:	301	case PT_DYNAMIC:
316	case PT_SHLIB:	302	case PT_SHLIB:
317	case PT_NOTE:	303	case PT_NOTE:
318	case PT_LOPROC:	304	case PT_LOPROC:
319	case PT_HIPROC:	305	case PT_HIPROC:
320	default:	306	default:
321	printf("segment p_type %d unknown\n", entry->p_type);	307	printf("segment p_type %d unknown\n", entry->p_type);
322	return EE_UNSUPPORTED;	308	return EE_UNSUPPORTED;
323	break;	309	break;
324	}	310	}
325	return EE_OK;	311	return EE_OK;
326	}	312	}
327		313
328	/** Load segment described by program header entry.	314	/** Load segment described by program header entry.
329	*	315	*
330	* @param elf Loader state.	316	* @param elf Loader state.
331	* @param entry Program header entry describing segment to be loaded.	317	* @param entry Program header entry describing segment to be loaded.
332	*	318	*
333	* @return EE_OK on success, error code otherwise.	319	* @return EE_OK on success, error code otherwise.
334	*/	320	*/
335	int load_segment(elf_ld_t elf, elf_segment_header_t entry)	321	int load_segment(elf_ld_t elf, elf_segment_header_t entry)
336	{	322	{
337	void *a;	323	void *a;
338	int flags = 0;	324	int flags = 0;
339	uintptr_t bias;	325	uintptr_t bias;
340	uintptr_t base;	326	uintptr_t base;
341	size_t mem_sz;	327	size_t mem_sz;
342	int rc;	328	int rc;
343		329
344	// printf("load segment at addr 0x%x, size 0x%x\n", entry->p_vaddr,	330	// printf("load segment at addr 0x%x, size 0x%x\n", entry->p_vaddr,
345	// entry->p_memsz);	331	// entry->p_memsz);
346		332
347	bias = elf->bias;	333	bias = elf->bias;
348		334
349	if (entry->p_align > 1) {	335	if (entry->p_align > 1) {
350	if ((entry->p_offset % entry->p_align) !=	336	if ((entry->p_offset % entry->p_align) !=
351	(entry->p_vaddr % entry->p_align)) {	337	(entry->p_vaddr % entry->p_align)) {
352	printf("align check 1 failed offset%%align=%d, "	338	printf("align check 1 failed offset%%align=%d, "
353	"vaddr%%align=%d\n",	339	"vaddr%%align=%d\n",
354	entry->p_offset % entry->p_align,	340	entry->p_offset % entry->p_align,
355	entry->p_vaddr % entry->p_align	341	entry->p_vaddr % entry->p_align
356	);	342	);
357	return EE_INVALID;	343	return EE_INVALID;
358	}	344	}
359	}	345	}
360		346
361	/* Final flags that will be set for the memory area */	347	/* Final flags that will be set for the memory area */
362		348
363	if (entry->p_flags & PF_X)	349	if (entry->p_flags & PF_X)
364	flags \|= AS_AREA_EXEC;	350	flags \|= AS_AREA_EXEC;
365	if (entry->p_flags & PF_W)	351	if (entry->p_flags & PF_W)
366	flags \|= AS_AREA_WRITE;	352	flags \|= AS_AREA_WRITE;
367	if (entry->p_flags & PF_R)	353	if (entry->p_flags & PF_R)
368	flags \|= AS_AREA_READ;	354	flags \|= AS_AREA_READ;
369	flags \|= AS_AREA_CACHEABLE;	355	flags \|= AS_AREA_CACHEABLE;
370		356
371	base = ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE);	357	base = ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE);
372	mem_sz = entry->p_memsz + (entry->p_vaddr - base);	358	mem_sz = entry->p_memsz + (entry->p_vaddr - base);
373		359
374	// printf("map to p_vaddr=0x%x-0x%x...\n", entry->p_vaddr + bias,	360	// printf("map to p_vaddr=0x%x-0x%x...\n", entry->p_vaddr + bias,
375	// entry->p_vaddr + bias + ALIGN_UP(entry->p_memsz, PAGE_SIZE));	361	// entry->p_vaddr + bias + ALIGN_UP(entry->p_memsz, PAGE_SIZE));
376		362
377	/*	363	/*
378	* For the course of loading, the area needs to be readable	364	* For the course of loading, the area needs to be readable
379	* and writeable.	365	* and writeable.
380	*/	366	*/
381	a = as_area_create((uint8_t *)base + bias, mem_sz,	367	a = as_area_create((uint8_t *)base + bias, mem_sz,
382	AS_AREA_READ \| AS_AREA_WRITE \| AS_AREA_CACHEABLE);	368	AS_AREA_READ \| AS_AREA_WRITE \| AS_AREA_CACHEABLE);
383	if (a == (void *)(-1)) {	369	if (a == (void *)(-1)) {
384	printf("memory mapping failed\n");	370	printf("memory mapping failed\n");
385	return EE_MEMORY;	371	return EE_MEMORY;
386	}	372	}
387		373
388	// printf("as_area_create(0x%lx, 0x%x, %d) -> 0x%lx\n",	374	// printf("as_area_create(0x%lx, 0x%x, %d) -> 0x%lx\n",
389	// entry->p_vaddr+bias, entry->p_memsz, flags, (uintptr_t)a);	375	// entry->p_vaddr+bias, entry->p_memsz, flags, (uintptr_t)a);
390		376
391	/*	377	/*
392	* Load segment data	378	* Load segment data
393	*/	379	*/
394	// printf("seek to %d\n", entry->p_offset);	380	// printf("seek to %d\n", entry->p_offset);
395	rc = lseek(elf->fd, entry->p_offset, SEEK_SET);	381	rc = lseek(elf->fd, entry->p_offset, SEEK_SET);
396	if (rc < 0) {	382	if (rc < 0) {
397	printf("seek error\n");	383	printf("seek error\n");
398	return EE_INVALID;	384	return EE_INVALID;
399	}	385	}
400		386
401	// printf("read 0x%x bytes to address 0x%x\n", entry->p_filesz, entry->p_vaddr+bias);	387	// printf("read 0x%x bytes to address 0x%x\n", entry->p_filesz, entry->p_vaddr+bias);
402	/* rc = read(fd, (void *)(entry->p_vaddr + bias), entry->p_filesz);	388	/* rc = read(fd, (void *)(entry->p_vaddr + bias), entry->p_filesz);
403	if (rc < 0) { printf("read error\n"); return EE_INVALID; }*/	389	if (rc < 0) { printf("read error\n"); return EE_INVALID; }*/
404		390
405	/* Long reads are not possible yet. Load segment picewise */	391	/* Long reads are not possible yet. Load segment picewise */
406		392
407	unsigned left, now;	393	unsigned left, now;
408	uint8_t *dp;	394	uint8_t *dp;
409		395
410	left = entry->p_filesz;	396	left = entry->p_filesz;
411	dp = (uint8_t *)(entry->p_vaddr + bias);	397	dp = (uint8_t *)(entry->p_vaddr + bias);
412		398
413	while (left > 0) {	399	while (left > 0) {
414	now = 16384;	400	now = 16384;
415	if (now > left) now = left;	401	if (now > left) now = left;
416		402
417	// printf("read %d...", now);	403	// printf("read %d...", now);
418	rc = my_read(elf->fd, dp, now);	404	rc = my_read(elf->fd, dp, now);
419	// printf("->%d\n", rc);	405	// printf("->%d\n", rc);
420		406
421	if (rc < 0) {	407	if (rc < 0) {
422	printf("read error\n");	408	printf("read error\n");
423	return EE_INVALID;	409	return EE_INVALID;
424	}	410	}
425		411
426	left -= now;	412	left -= now;
427	dp += now;	413	dp += now;
428	}	414	}
429		415
430	/*	416	/*
431	* The caller wants to modify the segments first. He will then	417	* The caller wants to modify the segments first. He will then
432	* need to set the right access mode and ensure SMC coherence.	418	* need to set the right access mode and ensure SMC coherence.
433	*/	419	*/
434	if ((elf->flags & ELDF_RW) != 0) return EE_OK;	420	if ((elf->flags & ELDF_RW) != 0) return EE_OK;
435		421
436	// printf("set area flags to %d\n", flags);	422	// printf("set area flags to %d\n", flags);
437	rc = as_area_change_flags((uint8_t *)entry->p_vaddr + bias, flags);	423	rc = as_area_change_flags((uint8_t *)entry->p_vaddr + bias, flags);
438	if (rc != 0) {	424	if (rc != 0) {
439	printf("failed to set memory area flags\n");	425	printf("failed to set memory area flags\n");
440	return EE_MEMORY;	426	return EE_MEMORY;
441	}	427	}
442		428
443	if (flags & AS_AREA_EXEC) {	429	if (flags & AS_AREA_EXEC) {
444	/* Enforce SMC coherence for the segment */	430	/* Enforce SMC coherence for the segment */
445	if (smc_coherence(entry->p_vaddr + bias, entry->p_filesz))	431	if (smc_coherence(entry->p_vaddr + bias, entry->p_filesz))
446	return EE_MEMORY;	432	return EE_MEMORY;
447	}	433	}
448		434
449	return EE_OK;	435	return EE_OK;
450	}	436	}
451		437
452	/** Process section header.	438	/** Process section header.
453	*	439	*
454	* @param elf Loader state.	440	* @param elf Loader state.
455	* @param entry Segment header.	441	* @param entry Segment header.
456	*	442	*
457	* @return EE_OK on success, error code otherwise.	443	* @return EE_OK on success, error code otherwise.
458	*/	444	*/
459	static int section_header(elf_ld_t elf, elf_section_header_t entry)	445	static int section_header(elf_ld_t elf, elf_section_header_t entry)
460	{	446	{
461	switch (entry->sh_type) {	447	switch (entry->sh_type) {
462	case SHT_PROGBITS:	448	case SHT_PROGBITS:
463	if (entry->sh_flags & SHF_TLS) {	449	if (entry->sh_flags & SHF_TLS) {
464	/* .tdata */	450	/* .tdata */
465	}	451	}
466	break;	452	break;
467	case SHT_NOBITS:	453	case SHT_NOBITS:
468	if (entry->sh_flags & SHF_TLS) {	454	if (entry->sh_flags & SHF_TLS) {
469	/* .tbss */	455	/* .tbss */
470	}	456	}
471	break;	457	break;
472	case SHT_DYNAMIC:	458	case SHT_DYNAMIC:
473	/* Record pointer to dynamic section into info structure */	459	/* Record pointer to dynamic section into info structure */
474	elf->info->dynamic =	460	elf->info->dynamic =
475	(void )((uint8_t )entry->sh_addr + elf->bias);	461	(void )((uint8_t )entry->sh_addr + elf->bias);
476	printf("dynamic section found at 0x%x\n",	462	printf("dynamic section found at 0x%x\n",
477	(uintptr_t)elf->info->dynamic);	463	(uintptr_t)elf->info->dynamic);
478	break;	464	break;
479	default:	465	default:
480	break;	466	break;
481	}	467	}
482		468
483	return EE_OK;	469	return EE_OK;
484	}	470	}
485		471
486	/** @}	472	/** @}
487	*/	473	*/
488		474

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(root)/branches/dynload/uspace/srv/loader/elf_load.c – Rev 3562 → 3681