binutils-gdb/bfd/pdb.c
Mark Harmstone 897a57a126 bfd/pdb: fix -Wmaybe-uninitialized warning
Initialize stream0_start to fix spurious -Wmaybe-uninitialized warning
on some versions of gcc.
2024-09-05 09:58:47 +01:00

865 lines
20 KiB
C

/* BFD back-end for PDB Multi-Stream Format archives.
Copyright (C) 2022-2024 Free Software Foundation, Inc.
This file is part of BFD, the Binary File Descriptor library.
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, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
/* This describes the MSF file archive format, which is used for the
PDB debug info generated by MSVC. See https://llvm.org/docs/PDB/MsfFile.html
for a full description of the format. */
#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
/* "Microsoft C/C++ MSF 7.00\r\n\x1a\x44\x53\0\0\0" */
static const uint8_t pdb_magic[] =
{ 0x4d, 0x69, 0x63, 0x72, 0x6f, 0x73, 0x6f, 0x66,
0x74, 0x20, 0x43, 0x2f, 0x43, 0x2b, 0x2b, 0x20,
0x4d, 0x53, 0x46, 0x20, 0x37, 0x2e, 0x30, 0x30,
0x0d, 0x0a, 0x1a, 0x44, 0x53, 0x00, 0x00, 0x00 };
#define arch_eltdata(bfd) ((struct areltdata *) ((bfd)->arelt_data))
static bfd_cleanup
pdb_archive_p (bfd *abfd)
{
int ret;
char magic[sizeof (pdb_magic)];
ret = bfd_read (magic, sizeof (magic), abfd);
if (ret != sizeof (magic))
{
bfd_set_error (bfd_error_wrong_format);
return NULL;
}
if (memcmp (magic, pdb_magic, sizeof (magic)))
{
bfd_set_error (bfd_error_wrong_format);
return NULL;
}
void *tdata = bfd_zalloc (abfd, sizeof (struct artdata));
if (tdata == NULL)
return NULL;
bfd_ardata (abfd) = tdata;
return _bfd_no_cleanup;
}
static bfd *
pdb_get_elt_at_index (bfd *abfd, symindex sym_index)
{
char int_buf[sizeof (uint32_t)];
uint32_t block_size, block_map_addr, block, num_files;
uint32_t first_dir_block, dir_offset, file_size, block_off, left;
char name[10];
bfd *file;
char *buf;
/* Get block_size. */
if (bfd_seek (abfd, sizeof (pdb_magic), SEEK_SET))
return NULL;
if (bfd_read (int_buf, sizeof (uint32_t), abfd) != sizeof (uint32_t))
{
bfd_set_error (bfd_error_malformed_archive);
return NULL;
}
block_size = bfd_getl32 (int_buf);
if ((block_size & -block_size) != block_size
|| block_size < 512
|| block_size > 4096)
{
bfd_set_error (bfd_error_malformed_archive);
return NULL;
}
/* Get block_map_addr. */
if (bfd_seek (abfd, 4 * sizeof (uint32_t), SEEK_CUR))
return NULL;
if (bfd_read (int_buf, sizeof (uint32_t), abfd) != sizeof (uint32_t))
{
bfd_set_error (bfd_error_malformed_archive);
return NULL;
}
block_map_addr = bfd_getl32 (int_buf);
/* Get num_files. */
if (bfd_seek (abfd, block_map_addr * block_size, SEEK_SET))
return NULL;
if (bfd_read (int_buf, sizeof (uint32_t), abfd) != sizeof (uint32_t))
{
bfd_set_error (bfd_error_malformed_archive);
return NULL;
}
first_dir_block = bfd_getl32 (int_buf);
if (bfd_seek (abfd, first_dir_block * block_size, SEEK_SET))
return NULL;
if (bfd_read (int_buf, sizeof (uint32_t), abfd) != sizeof (uint32_t))
{
bfd_set_error (bfd_error_malformed_archive);
return NULL;
}
num_files = bfd_getl32 (int_buf);
if (sym_index >= num_files)
{
bfd_set_error (bfd_error_no_more_archived_files);
return NULL;
}
/* Read file size. */
dir_offset = sizeof (uint32_t) * (sym_index + 1);
if (dir_offset >= block_size)
{
uint32_t block_map_addr_off;
block_map_addr_off = ((dir_offset / block_size) * sizeof (uint32_t));
if (bfd_seek (abfd, (block_map_addr * block_size) + block_map_addr_off,
SEEK_SET))
return NULL;
if (bfd_read (int_buf, sizeof (uint32_t), abfd) != sizeof (uint32_t))
{
bfd_set_error (bfd_error_malformed_archive);
return NULL;
}
block = bfd_getl32 (int_buf);
}
else
{
block = first_dir_block;
}
if (bfd_seek (abfd, (block * block_size) + (dir_offset % block_size),
SEEK_SET))
return NULL;
if (bfd_read (int_buf, sizeof (uint32_t), abfd) != sizeof (uint32_t))
{
bfd_set_error (bfd_error_malformed_archive);
return NULL;
}
file_size = bfd_getl32 (int_buf);
/* Undocumented? Seen on PDBs created by MSVC 2022. */
if (file_size == 0xffffffff)
file_size = 0;
/* Create BFD. */
/* Four hex digits is enough - even though MSF allows for 32 bits, the
PDB format itself only uses 16 bits for stream numbers. */
sprintf (name, "%04lx", sym_index);
file = bfd_create (name, abfd);
if (!file)
return NULL;
if (!bfd_make_writable (file))
goto fail;
file->arelt_data =
(struct areltdata *) bfd_zmalloc (sizeof (struct areltdata));
if (!file->arelt_data)
goto fail;
arch_eltdata (file)->parsed_size = file_size;
arch_eltdata (file)->key = sym_index;
if (file_size == 0)
return file;
block_off = 0;
/* Sum number of blocks in previous files. */
if (sym_index != 0)
{
dir_offset = sizeof (uint32_t);
if (bfd_seek (abfd, (first_dir_block * block_size) + sizeof (uint32_t),
SEEK_SET))
goto fail;
for (symindex i = 0; i < sym_index; i++)
{
uint32_t size, num_blocks;
if ((dir_offset % block_size) == 0)
{
uint32_t block_map_addr_off;
block_map_addr_off =
((dir_offset / block_size) * sizeof (uint32_t));
if (bfd_seek
(abfd, (block_map_addr * block_size) + block_map_addr_off,
SEEK_SET))
goto fail;
if (bfd_read (int_buf, sizeof (uint32_t), abfd) !=
sizeof (uint32_t))
{
bfd_set_error (bfd_error_malformed_archive);
goto fail;
}
block = bfd_getl32 (int_buf);
if (bfd_seek (abfd, block * block_size, SEEK_SET))
goto fail;
}
if (bfd_read (int_buf, sizeof (uint32_t), abfd) !=
sizeof (uint32_t))
{
bfd_set_error (bfd_error_malformed_archive);
goto fail;
}
size = bfd_getl32 (int_buf);
if (size == 0xffffffff)
size = 0;
num_blocks = (size + block_size - 1) / block_size;
block_off += num_blocks;
dir_offset += sizeof (uint32_t);
}
}
/* Read blocks, and write into new BFD. */
dir_offset = sizeof (uint32_t) * (num_files + block_off + 1);
if (dir_offset >= block_size)
{
uint32_t block_map_addr_off;
block_map_addr_off = ((dir_offset / block_size) * sizeof (uint32_t));
if (bfd_seek (abfd, (block_map_addr * block_size) + block_map_addr_off,
SEEK_SET))
goto fail;
if (bfd_read (int_buf, sizeof (uint32_t), abfd) != sizeof (uint32_t))
{
bfd_set_error (bfd_error_malformed_archive);
goto fail;
}
block = bfd_getl32 (int_buf);
}
else
{
block = first_dir_block;
}
buf = bfd_malloc (block_size);
if (!buf)
goto fail;
left = file_size;
do
{
uint32_t file_block, to_read;
if ((dir_offset % block_size) == 0 && left != file_size)
{
uint32_t block_map_addr_off;
block_map_addr_off =
((dir_offset / block_size) * sizeof (uint32_t));
if (bfd_seek
(abfd, (block_map_addr * block_size) + block_map_addr_off,
SEEK_SET))
goto fail2;
if (bfd_read (int_buf, sizeof (uint32_t), abfd) !=
sizeof (uint32_t))
{
bfd_set_error (bfd_error_malformed_archive);
goto fail2;
}
block = bfd_getl32 (int_buf);
}
if (bfd_seek (abfd, (block * block_size) + (dir_offset % block_size),
SEEK_SET))
goto fail2;
if (bfd_read (int_buf, sizeof (uint32_t), abfd) != sizeof (uint32_t))
{
bfd_set_error (bfd_error_malformed_archive);
goto fail2;
}
file_block = bfd_getl32 (int_buf);
if (bfd_seek (abfd, file_block * block_size, SEEK_SET))
goto fail2;
to_read = left > block_size ? block_size : left;
if (bfd_read (buf, to_read, abfd) != to_read)
{
bfd_set_error (bfd_error_malformed_archive);
goto fail2;
}
if (bfd_write (buf, to_read, file) != to_read)
goto fail2;
if (left > block_size)
left -= block_size;
else
break;
dir_offset += sizeof (uint32_t);
}
while (left > 0);
free (buf);
return file;
fail2:
free (buf);
fail:
bfd_close (file);
return NULL;
}
static bfd *
pdb_openr_next_archived_file (bfd *archive, bfd *last_file)
{
if (!last_file)
return pdb_get_elt_at_index (archive, 0);
else
return pdb_get_elt_at_index (archive, arch_eltdata (last_file)->key + 1);
}
static int
pdb_generic_stat_arch_elt (bfd *abfd, struct stat *buf)
{
buf->st_mtime = 0;
buf->st_uid = 0;
buf->st_gid = 0;
buf->st_mode = 0644;
buf->st_size = arch_eltdata (abfd)->parsed_size;
return 0;
}
static uint32_t
pdb_allocate_block (uint32_t *num_blocks, uint32_t block_size)
{
uint32_t block;
block = *num_blocks;
(*num_blocks)++;
/* If new interval, skip two blocks for free space map. */
if ((block % block_size) == 1)
{
block += 2;
(*num_blocks) += 2;
}
return block;
}
static bool
pdb_write_directory (bfd *abfd, uint32_t block_size, uint32_t num_files,
uint32_t block_map_addr, uint32_t * num_blocks,
uint32_t *stream0_start)
{
char tmp[sizeof (uint32_t)];
uint32_t block, left, block_map_off;
bfd *arelt;
char *buf;
/* Allocate first block for directory. */
block = pdb_allocate_block (num_blocks, block_size);
left = block_size;
/* Write allocated block no. at beginning of block map. */
if (bfd_seek (abfd, block_map_addr * block_size, SEEK_SET))
return false;
bfd_putl32 (block, tmp);
if (bfd_write (tmp, sizeof (uint32_t), abfd) != sizeof (uint32_t))
return false;
block_map_off = sizeof (uint32_t);
/* Write num_files at beginning of directory. */
if (bfd_seek (abfd, block * block_size, SEEK_SET))
return false;
bfd_putl32 (num_files, tmp);
if (bfd_write (tmp, sizeof (uint32_t), abfd) != sizeof (uint32_t))
return false;
left -= sizeof (uint32_t);
/* Write file sizes. */
arelt = abfd->archive_head;
while (arelt)
{
if (left == 0)
{
if (block_map_off == block_size) /* Too many blocks. */
{
bfd_set_error (bfd_error_invalid_operation);
return false;
}
block = pdb_allocate_block (num_blocks, block_size);
left = block_size;
if (bfd_seek
(abfd, (block_map_addr * block_size) + block_map_off, SEEK_SET))
return false;
bfd_putl32 (block, tmp);
if (bfd_write (tmp, sizeof (uint32_t), abfd) != sizeof (uint32_t))
return false;
block_map_off += sizeof (uint32_t);
if (bfd_seek (abfd, block * block_size, SEEK_SET))
return false;
}
bfd_putl32 (bfd_get_size (arelt), tmp);
if (bfd_write (tmp, sizeof (uint32_t), abfd) != sizeof (uint32_t))
return false;
left -= sizeof (uint32_t);
arelt = arelt->archive_next;
}
/* Write blocks. */
buf = bfd_malloc (block_size);
if (!buf)
return false;
arelt = abfd->archive_head;
while (arelt)
{
ufile_ptr size = bfd_get_size (arelt);
uint32_t req_blocks = (size + block_size - 1) / block_size;
if (bfd_seek (arelt, 0, SEEK_SET))
{
free (buf);
return false;
}
for (uint32_t i = 0; i < req_blocks; i++)
{
uint32_t file_block, to_read;
if (left == 0)
{
if (block_map_off == block_size) /* Too many blocks. */
{
bfd_set_error (bfd_error_invalid_operation);
free (buf);
return false;
}
block = pdb_allocate_block (num_blocks, block_size);
left = block_size;
if (bfd_seek
(abfd, (block_map_addr * block_size) + block_map_off,
SEEK_SET))
{
free (buf);
return false;
}
bfd_putl32 (block, tmp);
if (bfd_write (tmp, sizeof (uint32_t), abfd) !=
sizeof (uint32_t))
{
free (buf);
return false;
}
block_map_off += sizeof (uint32_t);
if (bfd_seek (abfd, block * block_size, SEEK_SET))
{
free (buf);
return false;
}
}
/* Allocate block and write number into directory. */
file_block = pdb_allocate_block (num_blocks, block_size);
bfd_putl32 (file_block, tmp);
if (bfd_write (tmp, sizeof (uint32_t), abfd) != sizeof (uint32_t))
{
free (buf);
return false;
}
if (arelt == abfd->archive_head && i == 0)
*stream0_start = file_block;
left -= sizeof (uint32_t);
/* Read file contents into buffer. */
to_read = size > block_size ? block_size : size;
if (bfd_read (buf, to_read, arelt) != to_read)
{
free (buf);
return false;
}
size -= to_read;
if (to_read < block_size)
memset (buf + to_read, 0, block_size - to_read);
if (bfd_seek (abfd, file_block * block_size, SEEK_SET))
{
free (buf);
return false;
}
/* Write file contents into allocated block. */
if (bfd_write (buf, block_size, abfd) != block_size)
{
free (buf);
return false;
}
if (bfd_seek
(abfd, (block * block_size) + block_size - left, SEEK_SET))
{
free (buf);
return false;
}
}
arelt = arelt->archive_next;
}
memset (buf, 0, left);
if (bfd_write (buf, left, abfd) != left)
{
free (buf);
return false;
}
free (buf);
return true;
}
static bool
pdb_write_bitmap (bfd *abfd, uint32_t block_size, uint32_t num_blocks,
uint32_t stream0_start)
{
char *buf;
uint32_t num_intervals = (num_blocks + block_size - 1) / block_size;
buf = bfd_malloc (block_size);
if (!buf)
return false;
for (uint32_t i = 0; i < num_intervals; i++)
{
if (bfd_seek (abfd, ((i * block_size) + 1) * block_size, SEEK_SET))
{
free (buf);
return false;
}
/* All of our blocks are contiguous, making our free block map
relatively simple. 0 = used, 1 = free. */
if (num_blocks >= 8)
memset (buf, 0,
(num_blocks / 8) >
block_size ? block_size : (num_blocks / 8));
if (num_blocks < block_size * 8)
{
unsigned int off = num_blocks / 8;
if (num_blocks % 8)
{
buf[off] = 256 - (1 << (num_blocks % 8));
off++;
}
if (off < block_size)
memset (buf + off, 0xff, block_size - off);
}
/* Mark the blocks allocated to stream 0 as free. This is because stream
0 is intended to be used for the previous MSF directory, to allow
atomic updates. This doesn't apply to us, as we rewrite the whole
file whenever any change is made. */
if (i == 0 && abfd->archive_head)
{
bfd *arelt = abfd->archive_head;
uint32_t stream0_blocks =
(bfd_get_size (arelt) + block_size - 1) / block_size;
if (stream0_start % 8)
{
unsigned int high_bit;
high_bit = (stream0_start % 8) + stream0_blocks;
if (high_bit > 8)
high_bit = 8;
buf[stream0_start / 8] |=
(1 << high_bit) - (1 << (stream0_start % 8));
stream0_blocks -= high_bit - (stream0_start % 8);
stream0_start += high_bit - (stream0_start % 8);
}
memset (buf + (stream0_start / 8), 0xff, stream0_blocks / 8);
stream0_start += stream0_blocks / 8;
stream0_blocks %= 8;
if (stream0_blocks > 0)
buf[stream0_start / 8] |= (1 << stream0_blocks) - 1;
}
if (num_blocks < block_size * 8)
num_blocks = 0;
else
num_blocks -= block_size * 8;
if (bfd_write (buf, block_size, abfd) != block_size)
return false;
}
free (buf);
return true;
}
static bool
pdb_write_contents (bfd *abfd)
{
char tmp[sizeof (uint32_t)];
const uint32_t block_size = 0x400;
uint32_t block_map_addr;
uint32_t num_blocks;
uint32_t num_files = 0;
uint32_t num_directory_bytes = sizeof (uint32_t);
uint32_t stream0_start = 0;
bfd *arelt;
if (bfd_write (pdb_magic, sizeof (pdb_magic), abfd) != sizeof (pdb_magic))
return false;
bfd_putl32 (block_size, tmp);
if (bfd_write (tmp, sizeof (uint32_t), abfd) != sizeof (uint32_t))
return false;
bfd_putl32 (1, tmp); /* Free block map block (always either 1 or 2). */
if (bfd_write (tmp, sizeof (uint32_t), abfd) != sizeof (uint32_t))
return false;
arelt = abfd->archive_head;
while (arelt)
{
uint32_t blocks_required =
(bfd_get_size (arelt) + block_size - 1) / block_size;
num_directory_bytes += sizeof (uint32_t); /* Size. */
num_directory_bytes += blocks_required * sizeof (uint32_t); /* Blocks. */
num_files++;
arelt = arelt->archive_next;
}
/* Superblock plus two bitmap blocks. */
num_blocks = 3;
/* Skip num_blocks for now. */
if (bfd_seek (abfd, sizeof (uint32_t), SEEK_CUR))
return false;
bfd_putl32 (num_directory_bytes, tmp);
if (bfd_write (tmp, sizeof (uint32_t), abfd) != sizeof (uint32_t))
return false;
/* Skip unknown uint32_t (always 0?). */
if (bfd_seek (abfd, sizeof (uint32_t), SEEK_CUR))
return false;
block_map_addr = pdb_allocate_block (&num_blocks, block_size);
bfd_putl32 (block_map_addr, tmp);
if (bfd_write (tmp, sizeof (uint32_t), abfd) != sizeof (uint32_t))
return false;
if (!pdb_write_directory
(abfd, block_size, num_files, block_map_addr, &num_blocks,
&stream0_start))
return false;
if (!pdb_write_bitmap (abfd, block_size, num_blocks, stream0_start))
return false;
/* Write num_blocks now we know it. */
if (bfd_seek
(abfd, sizeof (pdb_magic) + sizeof (uint32_t) + sizeof (uint32_t),
SEEK_SET))
return false;
bfd_putl32 (num_blocks, tmp);
if (bfd_write (tmp, sizeof (uint32_t), abfd) != sizeof (uint32_t))
return false;
return true;
}
#define pdb_bfd_free_cached_info _bfd_generic_bfd_free_cached_info
#define pdb_new_section_hook _bfd_generic_new_section_hook
#define pdb_get_section_contents _bfd_generic_get_section_contents
#define pdb_close_and_cleanup _bfd_generic_close_and_cleanup
#define pdb_slurp_armap _bfd_noarchive_slurp_armap
#define pdb_slurp_extended_name_table _bfd_noarchive_slurp_extended_name_table
#define pdb_construct_extended_name_table _bfd_noarchive_construct_extended_name_table
#define pdb_truncate_arname _bfd_noarchive_truncate_arname
#define pdb_write_armap _bfd_noarchive_write_armap
#define pdb_read_ar_hdr _bfd_noarchive_read_ar_hdr
#define pdb_write_ar_hdr _bfd_noarchive_write_ar_hdr
#define pdb_update_armap_timestamp _bfd_noarchive_update_armap_timestamp
const bfd_target pdb_vec =
{
"pdb",
bfd_target_unknown_flavour,
BFD_ENDIAN_LITTLE, /* target byte order */
BFD_ENDIAN_LITTLE, /* target headers byte order */
0, /* object flags */
0, /* section flags */
0, /* leading underscore */
' ', /* ar_pad_char */
16, /* ar_max_namelen */
0, /* match priority. */
TARGET_KEEP_UNUSED_SECTION_SYMBOLS, /* keep unused section symbols. */
bfd_getl64, bfd_getl_signed_64, bfd_putl64,
bfd_getl32, bfd_getl_signed_32, bfd_putl32,
bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* Data. */
bfd_getl64, bfd_getl_signed_64, bfd_putl64,
bfd_getl32, bfd_getl_signed_32, bfd_putl32,
bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* Hdrs. */
{ /* bfd_check_format */
_bfd_dummy_target,
_bfd_dummy_target,
pdb_archive_p,
_bfd_dummy_target
},
{ /* bfd_set_format */
_bfd_bool_bfd_false_error,
_bfd_bool_bfd_false_error,
_bfd_bool_bfd_true,
_bfd_bool_bfd_false_error
},
{ /* bfd_write_contents */
_bfd_bool_bfd_true,
_bfd_bool_bfd_false_error,
pdb_write_contents,
_bfd_bool_bfd_false_error
},
BFD_JUMP_TABLE_GENERIC (pdb),
BFD_JUMP_TABLE_COPY (_bfd_generic),
BFD_JUMP_TABLE_CORE (_bfd_nocore),
BFD_JUMP_TABLE_ARCHIVE (pdb),
BFD_JUMP_TABLE_SYMBOLS (_bfd_nosymbols),
BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
BFD_JUMP_TABLE_WRITE (_bfd_generic),
BFD_JUMP_TABLE_LINK (_bfd_nolink),
BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
NULL,
NULL
};