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);
 
/** 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, 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 = 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 == "/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 = my_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 3223	Rev 3315
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. */
-		75	static int my_read(int fd, char *buf, size_t len)
-		76	{
-		77	int cnt = 0;
-		78	do {
-		79	buf += cnt;
-		80	len -= cnt;
-		81	cnt = read(fd, buf, len);
-		82	} while ((cnt > 0) && ((len - cnt) > 0));
-		83
-		84	return cnt;
-		85	}
-		86
74	/** Load ELF binary from a file.	87	/** Load ELF binary from a file.
75	*	88	*
76	* 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
77	* 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
78	* 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
79	* 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
80	* pointed to by @a info.	93	* pointed to by @a info.
81	*	94	*
82	* @param file_name Path to the ELF file.	95	* @param file_name Path to the ELF file.
83	* @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.
84	* @param info Pointer to a structure for storing information	97	* @param info Pointer to a structure for storing information
85	* extracted from the binary.	98	* extracted from the binary.
86	*	99	*
87	* @return EOK on success or negative error code.	100	* @return EOK on success or negative error code.
88	*/	101	*/
89	int elf_load_file(char file_name, size_t so_bias, elf_info_t info)	102	int elf_load_file(char file_name, size_t so_bias, elf_info_t info)
90	{	103	{
91	elf_ld_t elf;	104	elf_ld_t elf;
92		105
93	int fd;	106	int fd;
94	int rc;	107	int rc;
95		108
96	// printf("open and read '%s'...\n", file_name);	109	// printf("open and read '%s'...\n", file_name);
97		110
98	fd = open(file_name, O_RDONLY);	111	fd = open(file_name, O_RDONLY);
99	if (fd < 0) {	112	if (fd < 0) {
100	printf("failed opening file\n");	113	printf("failed opening file\n");
101	return -1;	114	return -1;
102	}	115	}
103		116
104	elf.fd = fd;	117	elf.fd = fd;
105	elf.info = info;	118	elf.info = info;
106		119
107	rc = elf_load(&elf, so_bias);	120	rc = elf_load(&elf, so_bias);
108		121
109	close(fd);	122	close(fd);
110		123
111	return rc;	124	return rc;
112	}	125	}
113		126
114	/** Run an ELF executable.	127	/** Run an ELF executable.
115	*	128	*
116	* Transfers control to the entry point of an ELF executable loaded	129	* Transfers control to the entry point of an ELF executable loaded
117	* earlier with elf_load_file(). This function does not return.	130	* earlier with elf_load_file(). This function does not return.
118	*	131	*
119	* @param info Info structure filled earlier by elf_load_file()	132	* @param info Info structure filled earlier by elf_load_file()
120	*/	133	*/
121	void elf_run(elf_info_t info, pcb_t pcb)	134	void elf_run(elf_info_t info, pcb_t pcb)
122	{	135	{
123	program_run(info->entry, pcb);	136	program_run(info->entry, pcb);
124		137
125	/* not reached */	138	/* not reached */
126	}	139	}
127		140
128	/** Create the program control block (PCB).	141	/** Create the program control block (PCB).
129	*	142	*
130	* Fills the program control block @a pcb with information from	143	* Fills the program control block @a pcb with information from
131	* @a info.	144	* @a info.
132	*	145	*
133	* @param info Program info structure	146	* @param info Program info structure
134	* @return EOK on success or negative error code	147	* @return EOK on success or negative error code
135	*/	148	*/
136	void elf_create_pcb(elf_info_t info, pcb_t pcb)	149	void elf_create_pcb(elf_info_t info, pcb_t pcb)
137	{	150	{
138	pcb->entry = info->entry;	151	pcb->entry = info->entry;
139	pcb->dynamic = info->dynamic;	152	pcb->dynamic = info->dynamic;
140	}	153	}
141		154
142		155
143	/** Load an ELF binary.	156	/** Load an ELF binary.
144	*	157	*
145	* The @a elf structure contains the loader state, including	158	* The @a elf structure contains the loader state, including
146	* an open file, from which the binary will be loaded,	159	* an open file, from which the binary will be loaded,
147	* a pointer to the @c info structure etc.	160	* a pointer to the @c info structure etc.
148	*	161	*
149	* @param elf Pointer to loader state buffer.	162	* @param elf Pointer to loader state buffer.
150	* @param so_bias Bias to use if the file is a shared object.	163	* @param so_bias Bias to use if the file is a shared object.
151	* @return EE_OK on success or EE_xx error code.	164	* @return EE_OK on success or EE_xx error code.
152	*/	165	*/
153	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias)	166	static unsigned int elf_load(elf_ld_t *elf, size_t so_bias)
154	{	167	{
155	elf_header_t header_buf;	168	elf_header_t header_buf;
156	elf_header_t *header = &header_buf;	169	elf_header_t *header = &header_buf;
157	int i, rc;	170	int i, rc;
158		171
159	rc = read(elf->fd, header, sizeof(elf_header_t));	172	rc = my_read(elf->fd, header, sizeof(elf_header_t));
160	if (rc < 0) {	173	if (rc < 0) {
161	printf("read error\n");	174	printf("read error\n");
162	return EE_INVALID;	175	return EE_INVALID;
163	}	176	}
164		177
165	elf->header = header;	178	elf->header = header;
166		179
167	// printf("ELF-load:");	180	// printf("ELF-load:");
168	/* Identify ELF */	181	/* Identify ELF */
169	if (header->e_ident[EI_MAG0] != ELFMAG0 \|\|	182	if (header->e_ident[EI_MAG0] != ELFMAG0 \|\|
170	header->e_ident[EI_MAG1] != ELFMAG1 \|\|	183	header->e_ident[EI_MAG1] != ELFMAG1 \|\|
171	header->e_ident[EI_MAG2] != ELFMAG2 \|\|	184	header->e_ident[EI_MAG2] != ELFMAG2 \|\|
172	header->e_ident[EI_MAG3] != ELFMAG3) {	185	header->e_ident[EI_MAG3] != ELFMAG3) {
173	printf("invalid header\n");	186	printf("invalid header\n");
174	return EE_INVALID;	187	return EE_INVALID;
175	}	188	}
176		189
177	/* Identify ELF compatibility */	190	/* Identify ELF compatibility */
178	if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING \|\|	191	if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING \|\|
179	header->e_machine != ELF_MACHINE \|\|	192	header->e_machine != ELF_MACHINE \|\|
180	header->e_ident[EI_VERSION] != EV_CURRENT \|\|	193	header->e_ident[EI_VERSION] != EV_CURRENT \|\|
181	header->e_version != EV_CURRENT \|\|	194	header->e_version != EV_CURRENT \|\|
182	header->e_ident[EI_CLASS] != ELF_CLASS) {	195	header->e_ident[EI_CLASS] != ELF_CLASS) {
183	printf("incompatible data/version/class\n");	196	printf("incompatible data/version/class\n");
184	return EE_INCOMPATIBLE;	197	return EE_INCOMPATIBLE;
185	}	198	}
186		199
187	if (header->e_phentsize != sizeof(elf_segment_header_t)) {	200	if (header->e_phentsize != sizeof(elf_segment_header_t)) {
188	printf("e_phentsize:%d != %d\n", header->e_phentsize,	201	printf("e_phentsize:%d != %d\n", header->e_phentsize,
189	sizeof(elf_segment_header_t));	202	sizeof(elf_segment_header_t));
190	return EE_INCOMPATIBLE;	203	return EE_INCOMPATIBLE;
191	}	204	}
192		205
193	if (header->e_shentsize != sizeof(elf_section_header_t)) {	206	if (header->e_shentsize != sizeof(elf_section_header_t)) {
194	printf("e_shentsize:%d != %d\n", header->e_shentsize,	207	printf("e_shentsize:%d != %d\n", header->e_shentsize,
195	sizeof(elf_section_header_t));	208	sizeof(elf_section_header_t));
196	return EE_INCOMPATIBLE;	209	return EE_INCOMPATIBLE;
197	}	210	}
198		211
199	/* Check if the object type is supported. */	212	/* Check if the object type is supported. */
200	if (header->e_type != ET_EXEC && header->e_type != ET_DYN) {	213	if (header->e_type != ET_EXEC && header->e_type != ET_DYN) {
201	printf("Object type %d is not supported\n", header->e_type);	214	printf("Object type %d is not supported\n", header->e_type);
202	return EE_UNSUPPORTED;	215	return EE_UNSUPPORTED;
203	}	216	}
204		217
205	/* Shared objects can be loaded with a bias */	218	/* Shared objects can be loaded with a bias */
206	// printf("Object type: %d\n", header->e_type);	219	// printf("Object type: %d\n", header->e_type);
207	if (header->e_type == ET_DYN)	220	if (header->e_type == ET_DYN)
208	elf->bias = so_bias;	221	elf->bias = so_bias;
209	else	222	else
210	elf->bias = 0;	223	elf->bias = 0;
211		224
212	// printf("Bias set to 0x%x\n", elf->bias);	225	// printf("Bias set to 0x%x\n", elf->bias);
213	elf->info->interp = NULL;	226	elf->info->interp = NULL;
214	elf->info->dynamic = NULL;	227	elf->info->dynamic = NULL;
215		228
216	// printf("parse segments\n");	229	// printf("parse segments\n");
217		230
218	/* Walk through all segment headers and process them. */	231	/* Walk through all segment headers and process them. */
219	for (i = 0; i < header->e_phnum; i++) {	232	for (i = 0; i < header->e_phnum; i++) {
220	elf_segment_header_t segment_hdr;	233	elf_segment_header_t segment_hdr;
221		234
222	/* Seek to start of segment header */	235	/* Seek to start of segment header */
223	lseek(elf->fd, header->e_phoff	236	lseek(elf->fd, header->e_phoff
224	+ i * sizeof(elf_segment_header_t), SEEK_SET);	237	+ i * sizeof(elf_segment_header_t), SEEK_SET);
225		238
-		239	rc = my_read(elf->fd, &segment_hdr,
226	rc = read(elf->fd, &segment_hdr, sizeof(elf_segment_header_t));	240	sizeof(elf_segment_header_t));
227	if (rc < 0) {	241	if (rc < 0) {
228	printf("read error\n");	242	printf("read error\n");
229	return EE_INVALID;	243	return EE_INVALID;
230	}	244	}
231		245
232	rc = segment_header(elf, &segment_hdr);	246	rc = segment_header(elf, &segment_hdr);
233	if (rc != EE_OK)	247	if (rc != EE_OK)
234	return rc;	248	return rc;
235	}	249	}
236		250
237	// printf("parse sections\n");	251	// printf("parse sections\n");
238		252
239	/* Inspect all section headers and proccess them. */	253	/* Inspect all section headers and proccess them. */
240	for (i = 0; i < header->e_shnum; i++) {	254	for (i = 0; i < header->e_shnum; i++) {
241	elf_section_header_t section_hdr;	255	elf_section_header_t section_hdr;
242		256
243	/* Seek to start of section header */	257	/* Seek to start of section header */
244	lseek(elf->fd, header->e_shoff	258	lseek(elf->fd, header->e_shoff
245	+ i * sizeof(elf_section_header_t), SEEK_SET);	259	+ i * sizeof(elf_section_header_t), SEEK_SET);
246		260
-		261	rc = my_read(elf->fd, &section_hdr,
247	rc = read(elf->fd, &section_hdr, sizeof(elf_section_header_t));	262	sizeof(elf_section_header_t));
248	if (rc < 0) {	263	if (rc < 0) {
249	printf("read error\n");	264	printf("read error\n");
250	return EE_INVALID;	265	return EE_INVALID;
251	}	266	}
252		267
253	rc = section_header(elf, &section_hdr);	268	rc = section_header(elf, &section_hdr);
254	if (rc != EE_OK)	269	if (rc != EE_OK)
255	return rc;	270	return rc;
256	}	271	}
257		272
258	elf->info->entry =	273	elf->info->entry =
259	(entry_point_t)((uint8_t *)header->e_entry + elf->bias);	274	(entry_point_t)((uint8_t *)header->e_entry + elf->bias);
260		275
261	// printf("done\n");	276	// printf("done\n");
262		277
263	return EE_OK;	278	return EE_OK;
264	}	279	}
265		280
266	/** Print error message according to error code.	281	/** Print error message according to error code.
267	*	282	*
268	* @param rc Return code returned by elf_load().	283	* @param rc Return code returned by elf_load().
269	*	284	*
270	* @return NULL terminated description of error.	285	* @return NULL terminated description of error.
271	*/	286	*/
272	char *elf_error(unsigned int rc)	287	char *elf_error(unsigned int rc)
273	{	288	{
274	assert(rc < sizeof(error_codes) / sizeof(char *));	289	assert(rc < sizeof(error_codes) / sizeof(char *));
275		290
276	return error_codes[rc];	291	return error_codes[rc];
277	}	292	}
278		293
279	/** Process segment header.	294	/** Process segment header.
280	*	295	*
281	* @param entry Segment header.	296	* @param entry Segment header.
282	*	297	*
283	* @return EE_OK on success, error code otherwise.	298	* @return EE_OK on success, error code otherwise.
284	*/	299	*/
285	static int segment_header(elf_ld_t elf, elf_segment_header_t entry)	300	static int segment_header(elf_ld_t elf, elf_segment_header_t entry)
286	{	301	{
287	switch (entry->p_type) {	302	switch (entry->p_type) {
288	case PT_NULL:	303	case PT_NULL:
289	case PT_PHDR:	304	case PT_PHDR:
290	break;	305	break;
291	case PT_LOAD:	306	case PT_LOAD:
292	return load_segment(elf, entry);	307	return load_segment(elf, entry);
293	break;	308	break;
294	case PT_INTERP:	309	case PT_INTERP:
295	/* Assume silently interp == "/rtld.so" */	310	/* Assume silently interp == "/rtld.so" */
296	elf->info->interp = "/rtld.so";	311	elf->info->interp = "/rtld.so";
297	break;	312	break;
298	case PT_DYNAMIC:	313	case PT_DYNAMIC:
299	case PT_SHLIB:	314	case PT_SHLIB:
300	case PT_NOTE:	315	case PT_NOTE:
301	case PT_LOPROC:	316	case PT_LOPROC:
302	case PT_HIPROC:	317	case PT_HIPROC:
303	default:	318	default:
304	printf("segment p_type %d unknown\n", entry->p_type);	319	printf("segment p_type %d unknown\n", entry->p_type);
305	return EE_UNSUPPORTED;	320	return EE_UNSUPPORTED;
306	break;	321	break;
307	}	322	}
308	return EE_OK;	323	return EE_OK;
309	}	324	}
310		325
311	/** Load segment described by program header entry.	326	/** Load segment described by program header entry.
312	*	327	*
313	* @param elf Loader state.	328	* @param elf Loader state.
314	* @param entry Program header entry describing segment to be loaded.	329	* @param entry Program header entry describing segment to be loaded.
315	*	330	*
316	* @return EE_OK on success, error code otherwise.	331	* @return EE_OK on success, error code otherwise.
317	*/	332	*/
318	int load_segment(elf_ld_t elf, elf_segment_header_t entry)	333	int load_segment(elf_ld_t elf, elf_segment_header_t entry)
319	{	334	{
320	void *a;	335	void *a;
321	int flags = 0;	336	int flags = 0;
322	uintptr_t bias;	337	uintptr_t bias;
323	uintptr_t base;	338	uintptr_t base;
324	size_t mem_sz;	339	size_t mem_sz;
325	int rc;	340	int rc;
326		341
327	// printf("load segment at addr 0x%x, size 0x%x\n", entry->p_vaddr,	342	// printf("load segment at addr 0x%x, size 0x%x\n", entry->p_vaddr,
328	// entry->p_memsz);	343	// entry->p_memsz);
329		344
330	bias = elf->bias;	345	bias = elf->bias;
331		346
332	if (entry->p_align > 1) {	347	if (entry->p_align > 1) {
333	if ((entry->p_offset % entry->p_align) !=	348	if ((entry->p_offset % entry->p_align) !=
334	(entry->p_vaddr % entry->p_align)) {	349	(entry->p_vaddr % entry->p_align)) {
335	printf("align check 1 failed offset%%align=%d, "	350	printf("align check 1 failed offset%%align=%d, "
336	"vaddr%%align=%d\n",	351	"vaddr%%align=%d\n",
337	entry->p_offset % entry->p_align,	352	entry->p_offset % entry->p_align,
338	entry->p_vaddr % entry->p_align	353	entry->p_vaddr % entry->p_align
339	);	354	);
340	return EE_INVALID;	355	return EE_INVALID;
341	}	356	}
342	}	357	}
343		358
344	/* Final flags that will be set for the memory area */	359	/* Final flags that will be set for the memory area */
345		360
346	if (entry->p_flags & PF_X)	361	if (entry->p_flags & PF_X)
347	flags \|= AS_AREA_EXEC;	362	flags \|= AS_AREA_EXEC;
348	if (entry->p_flags & PF_W)	363	if (entry->p_flags & PF_W)
349	flags \|= AS_AREA_WRITE;	364	flags \|= AS_AREA_WRITE;
350	if (entry->p_flags & PF_R)	365	if (entry->p_flags & PF_R)
351	flags \|= AS_AREA_READ;	366	flags \|= AS_AREA_READ;
352	flags \|= AS_AREA_CACHEABLE;	367	flags \|= AS_AREA_CACHEABLE;
353		368
354	base = ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE);	369	base = ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE);
355	mem_sz = entry->p_memsz + (entry->p_vaddr - base);	370	mem_sz = entry->p_memsz + (entry->p_vaddr - base);
356		371
357	// printf("map to p_vaddr=0x%x-0x%x...\n", entry->p_vaddr + bias,	372	// printf("map to p_vaddr=0x%x-0x%x...\n", entry->p_vaddr + bias,
358	// entry->p_vaddr + bias + ALIGN_UP(entry->p_memsz, PAGE_SIZE));	373	// entry->p_vaddr + bias + ALIGN_UP(entry->p_memsz, PAGE_SIZE));
359		374
360	/*	375	/*
361	* For the course of loading, the area needs to be readable	376	* For the course of loading, the area needs to be readable
362	* and writeable.	377	* and writeable.
363	*/	378	*/
364	a = as_area_create((uint8_t *)base + bias,	379	a = as_area_create((uint8_t *)base + bias, mem_sz,
365	mem_sz, AS_AREA_READ \| AS_AREA_WRITE \| AS_AREA_CACHEABLE);	380	AS_AREA_READ \| AS_AREA_WRITE \| AS_AREA_CACHEABLE);
366	if (a == (void *)(-1)) {	381	if (a == (void *)(-1)) {
367	printf("memory mapping failed\n");	382	printf("memory mapping failed\n");
368	return EE_MEMORY;	383	return EE_MEMORY;
369	}	384	}
370		385
371	// printf("as_area_create(0x%lx, 0x%x, %d) -> 0x%lx\n",	386	// printf("as_area_create(0x%lx, 0x%x, %d) -> 0x%lx\n",
372	// entry->p_vaddr+bias, entry->p_memsz, flags, (uintptr_t)a);	387	// entry->p_vaddr+bias, entry->p_memsz, flags, (uintptr_t)a);
373		388
374	/*	389	/*
375	* Load segment data	390	* Load segment data
376	*/	391	*/
377	// printf("seek to %d\n", entry->p_offset);	392	// printf("seek to %d\n", entry->p_offset);
378	rc = lseek(elf->fd, entry->p_offset, SEEK_SET);	393	rc = lseek(elf->fd, entry->p_offset, SEEK_SET);
379	if (rc < 0) {	394	if (rc < 0) {
380	printf("seek error\n");	395	printf("seek error\n");
381	return EE_INVALID;	396	return EE_INVALID;
382	}	397	}
383		398
384	// printf("read 0x%x bytes to address 0x%x\n", entry->p_filesz, entry->p_vaddr+bias);	399	// printf("read 0x%x bytes to address 0x%x\n", entry->p_filesz, entry->p_vaddr+bias);
385	/* rc = read(fd, (void *)(entry->p_vaddr + bias), entry->p_filesz);	400	/* rc = read(fd, (void *)(entry->p_vaddr + bias), entry->p_filesz);
386	if (rc < 0) { printf("read error\n"); return EE_INVALID; }*/	401	if (rc < 0) { printf("read error\n"); return EE_INVALID; }*/
387		402
388	/* Long reads are not possible yet. Load segment picewise */	403	/* Long reads are not possible yet. Load segment picewise */
389		404
390	unsigned left, now;	405	unsigned left, now;
391	uint8_t *dp;	406	uint8_t *dp;
392		407
393	left = entry->p_filesz;	408	left = entry->p_filesz;
394	dp = (uint8_t *)(entry->p_vaddr + bias);	409	dp = (uint8_t *)(entry->p_vaddr + bias);
395		410
396	while (left > 0) {	411	while (left > 0) {
397	now = 16384;	412	now = 16384;
398	if (now > left) now = left;	413	if (now > left) now = left;
399		414
400	// printf("read %d...", now);	415	// printf("read %d...", now);
401	rc = read(elf->fd, dp, now);	416	rc = my_read(elf->fd, dp, now);
402	// printf("->%d\n", rc);	417	// printf("->%d\n", rc);
403		418
404	if (rc < 0) {	419	if (rc < 0) {
405	printf("read error\n");	420	printf("read error\n");
406	return EE_INVALID;	421	return EE_INVALID;
407	}	422	}
408		423
409	left -= now;	424	left -= now;
410	dp += now;	425	dp += now;
411	}	426	}
412		427
413	// printf("set area flags to %d\n", flags);	428	// printf("set area flags to %d\n", flags);
414	rc = as_area_change_flags((uint8_t *)entry->p_vaddr + bias, flags);	429	rc = as_area_change_flags((uint8_t *)entry->p_vaddr + bias, flags);
415	if (rc != 0) {	430	if (rc != 0) {
416	printf("failed to set memory area flags\n");	431	printf("failed to set memory area flags\n");
417	return EE_MEMORY;	432	return EE_MEMORY;
418	}	433	}
419		434
420	if (flags & AS_AREA_EXEC) {	435	if (flags & AS_AREA_EXEC) {
421	/* Enforce SMC coherence for the segment */	436	/* Enforce SMC coherence for the segment */
422	if (smc_coherence(entry->p_vaddr + bias, entry->p_filesz))	437	if (smc_coherence(entry->p_vaddr + bias, entry->p_filesz))
423	return EE_MEMORY;	438	return EE_MEMORY;
424	}	439	}
425		440
426	return EE_OK;	441	return EE_OK;
427	}	442	}
428		443
429	/** Process section header.	444	/** Process section header.
430	*	445	*
431	* @param elf Loader state.	446	* @param elf Loader state.
432	* @param entry Segment header.	447	* @param entry Segment header.
433	*	448	*
434	* @return EE_OK on success, error code otherwise.	449	* @return EE_OK on success, error code otherwise.
435	*/	450	*/
436	static int section_header(elf_ld_t elf, elf_section_header_t entry)	451	static int section_header(elf_ld_t elf, elf_section_header_t entry)
437	{	452	{
438	switch (entry->sh_type) {	453	switch (entry->sh_type) {
439	case SHT_PROGBITS:	454	case SHT_PROGBITS:
440	if (entry->sh_flags & SHF_TLS) {	455	if (entry->sh_flags & SHF_TLS) {
441	/* .tdata */	456	/* .tdata */
442	}	457	}
443	break;	458	break;
444	case SHT_NOBITS:	459	case SHT_NOBITS:
445	if (entry->sh_flags & SHF_TLS) {	460	if (entry->sh_flags & SHF_TLS) {
446	/* .tbss */	461	/* .tbss */
447	}	462	}
448	break;	463	break;
449	case SHT_DYNAMIC:	464	case SHT_DYNAMIC:
450	/* Record pointer to dynamic section into info structure */	465	/* Record pointer to dynamic section into info structure */
451	elf->info->dynamic =	466	elf->info->dynamic =
452	(void )((uint8_t )entry->sh_addr + elf->bias);	467	(void )((uint8_t )entry->sh_addr + elf->bias);
453	printf("dynamic section found at 0x%x\n",	468	printf("dynamic section found at 0x%x\n",
454	(uintptr_t)elf->info->dynamic);	469	(uintptr_t)elf->info->dynamic);
455	break;	470	break;
456	default:	471	default:
457	break;	472	break;
458	}	473	}
459		474
460	return EE_OK;	475	return EE_OK;
461	}	476	}
462		477
463	/** @}	478	/** @}
464	*/	479	*/
465		480

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/loader/elf_load.c @ 4440 – Rev 3223 → 3315