314 lines
7.4 KiB
C
314 lines
7.4 KiB
C
/* Copyright 2013-2014 Free Software Foundation, Inc.
|
|
|
|
This file is part of GDB.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
#include <errno.h>
|
|
#include <stdarg.h>
|
|
#include <stdint.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
|
|
typedef struct
|
|
{
|
|
unsigned char e_ident[16];
|
|
uint16_t e_type;
|
|
uint16_t e_machine;
|
|
uint32_t e_version;
|
|
uint32_t e_entry;
|
|
uint32_t e_phoff;
|
|
uint32_t e_shoff;
|
|
uint32_t e_flags;
|
|
uint16_t e_ehsize;
|
|
uint16_t e_phentsize;
|
|
uint16_t e_phnum;
|
|
uint16_t e_shentsize;
|
|
uint16_t e_shnum;
|
|
uint16_t e_shstrndx;
|
|
} Elf32_Ehdr;
|
|
|
|
typedef struct
|
|
{
|
|
unsigned char e_ident[16];
|
|
uint16_t e_type;
|
|
uint16_t e_machine;
|
|
uint32_t e_version;
|
|
uint64_t e_entry;
|
|
uint64_t e_phoff;
|
|
uint64_t e_shoff;
|
|
uint32_t e_flags;
|
|
uint16_t e_ehsize;
|
|
uint16_t e_phentsize;
|
|
uint16_t e_phnum;
|
|
uint16_t e_shentsize;
|
|
uint16_t e_shnum;
|
|
uint16_t e_shstrndx;
|
|
} Elf64_Ehdr;
|
|
|
|
typedef struct
|
|
{
|
|
uint32_t p_type;
|
|
uint32_t p_offset;
|
|
uint32_t p_vaddr;
|
|
uint32_t p_paddr;
|
|
uint32_t p_filesz;
|
|
uint32_t p_memsz;
|
|
uint32_t p_flags;
|
|
uint32_t p_align;
|
|
} Elf32_Phdr;
|
|
|
|
typedef struct
|
|
{
|
|
uint32_t p_type;
|
|
uint32_t p_flags;
|
|
uint64_t p_offset;
|
|
uint64_t p_vaddr;
|
|
uint64_t p_paddr;
|
|
uint64_t p_filesz;
|
|
uint64_t p_memsz;
|
|
uint64_t p_align;
|
|
} Elf64_Phdr;
|
|
|
|
struct elfbuf
|
|
{
|
|
const char *path;
|
|
unsigned char *buf;
|
|
size_t len;
|
|
enum { ELFCLASS32 = 1,
|
|
ELFCLASS64 = 2 } ei_class;
|
|
};
|
|
|
|
#define ELFBUF_EHDR_LEN(elf) \
|
|
((elf)->ei_class == ELFCLASS32 ? sizeof (Elf32_Ehdr) : \
|
|
sizeof (Elf64_Ehdr))
|
|
|
|
#define ELFBUF_EHDR(elf, memb) \
|
|
((elf)->ei_class == ELFCLASS32 ? \
|
|
((Elf32_Ehdr *) (elf)->buf)->memb \
|
|
: ((Elf64_Ehdr *) (elf)->buf)->memb)
|
|
|
|
#define ELFBUF_PHDR_LEN(elf) \
|
|
((elf)->ei_class == ELFCLASS32 ? sizeof (Elf32_Phdr) : \
|
|
sizeof (Elf64_Phdr))
|
|
|
|
#define ELFBUF_PHDR(elf, idx, memb) \
|
|
((elf)->ei_class == ELFCLASS32 ? \
|
|
((Elf32_Phdr *) &(elf)->buf[((Elf32_Ehdr *)(elf)->buf) \
|
|
->e_phoff])[idx].memb \
|
|
: ((Elf64_Phdr *) &(elf)->buf[((Elf64_Ehdr *)(elf)->buf) \
|
|
->e_phoff])[idx].memb)
|
|
|
|
static void
|
|
exit_with_msg(const char *fmt, ...)
|
|
{
|
|
va_list ap;
|
|
|
|
fflush (stdout);
|
|
va_start (ap, fmt);
|
|
vfprintf (stderr, fmt, ap);
|
|
va_end (ap);
|
|
|
|
if (errno)
|
|
{
|
|
fputs (": ", stderr);
|
|
perror (NULL);
|
|
}
|
|
else
|
|
fputc ('\n', stderr);
|
|
exit (1);
|
|
}
|
|
|
|
static void
|
|
read_file (unsigned char **buf_ptr, size_t *len_ptr, FILE *fp)
|
|
{
|
|
size_t len = 0;
|
|
size_t size = 1024;
|
|
size_t chunk;
|
|
unsigned char *buf = malloc (size);
|
|
|
|
while ((chunk = fread (buf + len, 1, size - len, fp)) == size - len)
|
|
{
|
|
len = size;
|
|
size *= 2;
|
|
buf = realloc (buf, size);
|
|
}
|
|
len += chunk;
|
|
*buf_ptr = buf;
|
|
*len_ptr = len;
|
|
}
|
|
|
|
static void
|
|
write_file (unsigned char *buf, size_t len, FILE *fp)
|
|
{
|
|
fwrite (buf, 1, len, fp);
|
|
}
|
|
|
|
static void
|
|
elfbuf_init_from_file (struct elfbuf *elf, const char *path)
|
|
{
|
|
FILE *fp = fopen (path, "rb");
|
|
unsigned char *buf;
|
|
size_t len;
|
|
|
|
if (fp == NULL)
|
|
exit_with_msg ("%s", path);
|
|
|
|
read_file (&buf, &len, fp);
|
|
fclose (fp);
|
|
|
|
/* Validate ELF identification. */
|
|
if (len < 16
|
|
|| buf[0] != 0x7f || buf[1] != 0x45 || buf[2] != 0x4c || buf[3] != 0x46
|
|
|| buf[4] < 1 || buf[4] > 2 || buf[5] < 1 || buf[5] > 2)
|
|
exit_with_msg ("%s: unsupported or invalid ELF file", path);
|
|
|
|
elf->path = path;
|
|
elf->buf = buf;
|
|
elf->len = len;
|
|
elf->ei_class = buf[4];
|
|
|
|
if (ELFBUF_EHDR_LEN (elf) > len
|
|
|| ELFBUF_EHDR (elf, e_phoff) > len
|
|
|| ELFBUF_EHDR (elf, e_phnum) > ((len - ELFBUF_EHDR (elf, e_phoff))
|
|
/ ELFBUF_PHDR_LEN (elf)) )
|
|
exit_with_msg ("%s: unexpected end of data", path);
|
|
|
|
if (ELFBUF_EHDR (elf, e_phentsize) != ELFBUF_PHDR_LEN (elf))
|
|
exit_with_msg ("%s: inconsistent ELF header", path);
|
|
}
|
|
|
|
static void
|
|
elfbuf_write_to_file (struct elfbuf *elf, const char *path)
|
|
{
|
|
FILE *fp = fopen (path, "wb");
|
|
|
|
if (fp == NULL)
|
|
exit_with_msg ("%s", path);
|
|
|
|
write_file (elf->buf, elf->len, fp);
|
|
fclose (fp);
|
|
}
|
|
|
|
/* In the auxv note starting at OFFSET with size LEN, mask the hwcap
|
|
field using the HWCAP_MASK. */
|
|
|
|
static void
|
|
elfbuf_handle_auxv (struct elfbuf *elf, size_t offset, size_t len,
|
|
unsigned long hwcap_mask)
|
|
{
|
|
size_t i;
|
|
uint32_t *auxv32 = (uint32_t *) (elf->buf + offset);
|
|
uint64_t *auxv64 = (uint64_t *) auxv32;
|
|
size_t entry_size = elf->ei_class == ELFCLASS32 ?
|
|
sizeof (auxv32[0]) : sizeof (auxv64[0]);
|
|
|
|
for (i = 0; i < len / entry_size; i++)
|
|
{
|
|
uint64_t auxv_type = elf->ei_class == ELFCLASS32 ?
|
|
auxv32[2 * i] : auxv64[2 * i];
|
|
|
|
if (auxv_type == 0)
|
|
break;
|
|
if (auxv_type != 16)
|
|
continue;
|
|
|
|
if (elf->ei_class == ELFCLASS32)
|
|
auxv32[2 * i + 1] &= (uint32_t) hwcap_mask;
|
|
else
|
|
auxv64[2 * i + 1] &= (uint64_t) hwcap_mask;
|
|
}
|
|
}
|
|
|
|
/* In the note segment starting at OFFSET with size LEN, make notes
|
|
with type NOTE_TYPE unrecognizable by GDB. Also, mask the hwcap
|
|
field of any auxv notes using the HWCAP_MASK. */
|
|
|
|
static void
|
|
elfbuf_handle_note_segment (struct elfbuf *elf, size_t offset, size_t len,
|
|
unsigned note_type, unsigned long hwcap_mask)
|
|
{
|
|
size_t pos = 0;
|
|
|
|
while (pos + 12 < len)
|
|
{
|
|
uint32_t *note = (uint32_t *) (elf->buf + offset + pos);
|
|
size_t desc_pos = pos + 12 + ((note[0] + 3) & ~3);
|
|
size_t next_pos = desc_pos + ((note[1] + 3) & ~3);
|
|
|
|
if (desc_pos > len || next_pos > len)
|
|
exit_with_msg ("%s: corrupt notes data", elf->path);
|
|
|
|
if (note[2] == note_type)
|
|
note[2] |= 0xff000000;
|
|
else if (note[2] == 6 && hwcap_mask != 0)
|
|
elfbuf_handle_auxv (elf, offset + desc_pos, note[1],
|
|
hwcap_mask);
|
|
pos = next_pos;
|
|
}
|
|
}
|
|
|
|
static void
|
|
elfbuf_handle_core_notes (struct elfbuf *elf, unsigned note_type,
|
|
unsigned long hwcap_mask)
|
|
{
|
|
unsigned ph_idx;
|
|
|
|
if (ELFBUF_EHDR (elf, e_type) != 4)
|
|
exit_with_msg ("%s: not a core file", elf->path);
|
|
|
|
/* Iterate over program headers. */
|
|
for (ph_idx = 0; ph_idx != ELFBUF_EHDR (elf, e_phnum); ph_idx++)
|
|
{
|
|
size_t offset = ELFBUF_PHDR (elf, ph_idx, p_offset);
|
|
size_t filesz = ELFBUF_PHDR (elf, ph_idx, p_filesz);
|
|
|
|
if (offset > elf->len || filesz > elf->len - offset)
|
|
exit_with_msg ("%s: unexpected end of data", elf->path);
|
|
|
|
/* Deal with NOTE segments only. */
|
|
if (ELFBUF_PHDR (elf, ph_idx, p_type) != 4)
|
|
continue;
|
|
elfbuf_handle_note_segment (elf, offset, filesz, note_type,
|
|
hwcap_mask);
|
|
}
|
|
}
|
|
|
|
int
|
|
main (int argc, char *argv[])
|
|
{
|
|
unsigned note_type;
|
|
unsigned long hwcap_mask = 0;
|
|
struct elfbuf elf;
|
|
|
|
if (argc < 4)
|
|
{
|
|
abort ();
|
|
}
|
|
|
|
if (sscanf (argv[3], "%u", ¬e_type) != 1)
|
|
exit_with_msg ("%s: bad command line arguments\n", argv[0]);
|
|
|
|
if (argc >= 5)
|
|
{
|
|
if (sscanf (argv[4], "%lu", &hwcap_mask) != 1)
|
|
exit_with_msg ("%s: bad command line arguments\n", argv[0]);
|
|
}
|
|
|
|
elfbuf_init_from_file (&elf, argv[1]);
|
|
elfbuf_handle_core_notes (&elf, note_type, hwcap_mask);
|
|
elfbuf_write_to_file (&elf, argv[2]);
|
|
|
|
return 0;
|
|
}
|