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/*
* DA manager
*
* Copyright (c) 2000 - 2013 Samsung Electronics Co., Ltd. All rights reserved.
*
* Contact:
*
* Cherepanov Vitaliy <v.cherepanov@samsung.com>
* Dmitry Bogatov <d.bogatov@samsung.com>
* Nikita Kalyazin <n.kalyazin@samsung.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Contributors:
* - Samsung RnD Institute Russia
*
*/
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
#include <elf.h>
#include <stdbool.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include "elf.h"
#define SIZEOF_VOID_P 4
#if SIZEOF_VOID_P == 8
typedef Elf64_Ehdr Elf_Ehdr;
typedef Elf64_Shdr Elf_Shdr;
#elif SIZEOF_VOID_P == 4
typedef Elf32_Ehdr Elf_Ehdr;
typedef Elf32_Shdr Elf_Shdr;
#else
#error "Unknown void* size"
#endif
static size_t fsize(int fd)
{
struct stat buf;
fstat(fd, &buf);
return buf.st_size;
}
static void *mmap_file(const char *filepath, size_t * len)
{
int fd = open(filepath, O_RDONLY);
if (fd < 0)
return NULL;
*len = fsize(fd);
void *mem = mmap(NULL, *len, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
return mem == MAP_FAILED ? NULL : mem;
}
static const Elf_Shdr *elf_find_debug_header(const void *obj)
{
const Elf_Ehdr *elf_header = obj;
const Elf_Shdr *section_table = obj + elf_header->e_shoff;
const Elf_Shdr *string_entry = section_table + elf_header->e_shstrndx;
const char *string_section = obj + string_entry->sh_offset;
int index;
for (index = 0; index != elf_header->e_shnum; ++index) {
const Elf_Shdr *entry = section_table + index;
if (!strcmp(".debug_str", string_section + entry->sh_name))
return entry;
}
return NULL;
}
static int read_elf_header(Elf_Ehdr * header, const char *filepath)
{
int fd = open(filepath, O_RDONLY);
if (fd < 0)
return -ENOENT;
bool read_failed = read(fd, header, sizeof(*header)) != sizeof(*header);
close(fd);
return read_failed ? -EIO : 0;
}
static int elf_type(const char *filepath)
{
Elf_Ehdr header;
int err = read_elf_header(&header, filepath);
return err ? err : header.e_type;
}
uint32_t get_binary_type(const char *path)
{
int type = elf_type(path);
switch (type) {
case ET_DYN:
return BINARY_TYPE_PIE;
case ET_EXEC:
return BINARY_TYPE_NO_PIE;
default:
return BINARY_TYPE_UNKNOWN;
}
}
static int is_like_absolute_path(const char *str)
{
if (*str == '/')
return 1;
if (isupper(*str) && str[1] == ':' && str[2] == '\\')
return 1;
return 0;
}
void get_build_dir(char builddir[PATH_MAX], const char *filename)
{
size_t len;
void *filemem = mmap_file(filename, &len);
if (filemem) {
const Elf_Shdr *debug_header = elf_find_debug_header(filemem);
if (debug_header) {
const char *debug_section =
filemem + debug_header->sh_offset;
const char *debug_section_end =
debug_section + debug_header->sh_size;
const char *p = debug_section;
/* `is_like_absolute_path' checks three chars forward. */
while (p < debug_section_end - 3) {
if (is_like_absolute_path(p)) {
snprintf(builddir, PATH_MAX, "%s", p);
return;
}
p = 1 + memchr(p, '\0', debug_section_end - p);
}
}
munmap(filemem, len);
}
*builddir = '\0';
}
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