bfd_get_size cache

We have calls to bfd_get_size when swapping in ELF section headers.
Since object files can have a large number of sections, it's worth
caching the file size rather than making lots of stat system calls.

	* bfd.c (struct bfd): Move format and direction to other
	bitfields.  Add "size".
	* bfdio.c (bfd_get_size): Cache size when not writing file.
	* opncls.c (bfd_get_debug_link_info_1): Allow for bfd_get_size
	returning zero, ie. unknown.
	(bfd_get_alt_debug_link_info): Likewise.
	* bfd-in2.h: Regenerate.
This commit is contained in:
Alan Modra 2020-02-19 13:14:28 +10:30
parent 7c5fa58ea9
commit b03202e32c
5 changed files with 59 additions and 20 deletions

View file

@ -1,3 +1,13 @@
2020-02-19 Alan Modra <amodra@gmail.com>
* bfd.c (struct bfd): Move format and direction to other
bitfields. Add "size".
* bfdio.c (bfd_get_size): Cache size when not writing file.
* opncls.c (bfd_get_debug_link_info_1): Allow for bfd_get_size
returning zero, ie. unknown.
(bfd_get_alt_debug_link_info): Likewise.
* bfd-in2.h: Regenerate.
2020-02-19 Alan Modra <amodra@gmail.com>
* coffgen.c (_bfd_coff_get_external_symbols): Don't call

View file

@ -6497,12 +6497,6 @@ struct bfd
/* A unique identifier of the BFD */
unsigned int id;
/* The format which belongs to the BFD. (object, core, etc.) */
ENUM_BITFIELD (bfd_format) format : 3;
/* The direction with which the BFD was opened. */
ENUM_BITFIELD (bfd_direction) direction : 2;
/* Format_specific flags. */
flagword flags;
@ -6606,6 +6600,12 @@ struct bfd
| BFD_PLUGIN | BFD_TRADITIONAL_FORMAT | BFD_DETERMINISTIC_OUTPUT \
| BFD_COMPRESS_GABI | BFD_CONVERT_ELF_COMMON | BFD_USE_ELF_STT_COMMON)
/* The format which belongs to the BFD. (object, core, etc.) */
ENUM_BITFIELD (bfd_format) format : 3;
/* The direction with which the BFD was opened. */
ENUM_BITFIELD (bfd_direction) direction : 2;
/* Is the file descriptor being cached? That is, can it be closed as
needed, and re-opened when accessed later? */
unsigned int cacheable : 1;
@ -6706,6 +6706,11 @@ struct bfd
/* Pointer to structure which contains architecture information. */
const struct bfd_arch_info *arch_info;
/* Cached length of file for bfd_get_size. 0 until bfd_get_size is
called, 1 if stat returns an error or the file size is too large to
return in ufile_ptr. Both 0 and 1 should be treated as "unknown". */
ufile_ptr size;
/* Stuff only useful for archives. */
void *arelt_data;
struct bfd *my_archive; /* The containing archive BFD. */

View file

@ -85,12 +85,6 @@ CODE_FRAGMENT
. {* A unique identifier of the BFD *}
. unsigned int id;
.
. {* The format which belongs to the BFD. (object, core, etc.) *}
. ENUM_BITFIELD (bfd_format) format : 3;
.
. {* The direction with which the BFD was opened. *}
. ENUM_BITFIELD (bfd_direction) direction : 2;
.
. {* Format_specific flags. *}
. flagword flags;
.
@ -194,6 +188,12 @@ CODE_FRAGMENT
. | BFD_PLUGIN | BFD_TRADITIONAL_FORMAT | BFD_DETERMINISTIC_OUTPUT \
. | BFD_COMPRESS_GABI | BFD_CONVERT_ELF_COMMON | BFD_USE_ELF_STT_COMMON)
.
. {* The format which belongs to the BFD. (object, core, etc.) *}
. ENUM_BITFIELD (bfd_format) format : 3;
.
. {* The direction with which the BFD was opened. *}
. ENUM_BITFIELD (bfd_direction) direction : 2;
.
. {* Is the file descriptor being cached? That is, can it be closed as
. needed, and re-opened when accessed later? *}
. unsigned int cacheable : 1;
@ -294,6 +294,11 @@ CODE_FRAGMENT
. {* Pointer to structure which contains architecture information. *}
. const struct bfd_arch_info *arch_info;
.
. {* Cached length of file for bfd_get_size. 0 until bfd_get_size is
. called, 1 if stat returns an error or the file size is too large to
. return in ufile_ptr. Both 0 and 1 should be treated as "unknown". *}
. ufile_ptr size;
.
. {* Stuff only useful for archives. *}
. void *arelt_data;
. struct bfd *my_archive; {* The containing archive BFD. *}

View file

@ -415,17 +415,32 @@ DESCRIPTION
of space for the 15 bazillon byte table it is about to read.
This function at least allows us to answer the question, "is the
size reasonable?".
A return value of zero indicates the file size is unknown.
*/
ufile_ptr
bfd_get_size (bfd *abfd)
{
/* A size of 0 means we haven't yet called bfd_stat. A size of 1
means we have a cached value of 0, ie. unknown. */
if (abfd->size <= 1 || bfd_write_p (abfd))
{
struct stat buf;
if (bfd_stat (abfd, &buf) != 0)
if (abfd->size == 1 && !bfd_write_p (abfd))
return 0;
return buf.st_size;
if (bfd_stat (abfd, &buf) != 0
|| buf.st_size == 0
|| buf.st_size - (ufile_ptr) buf.st_size != 0)
{
abfd->size = 1;
return 0;
}
abfd->size = buf.st_size;
}
return abfd->size;
}
/*

View file

@ -1209,6 +1209,7 @@ bfd_get_debug_link_info_1 (bfd *abfd, void *crc32_out)
unsigned int crc_offset;
char *name;
bfd_size_type size;
ufile_ptr file_size;
BFD_ASSERT (abfd);
BFD_ASSERT (crc32_out);
@ -1219,9 +1220,10 @@ bfd_get_debug_link_info_1 (bfd *abfd, void *crc32_out)
return NULL;
size = bfd_section_size (sect);
file_size = bfd_get_size (abfd);
/* PR 22794: Make sure that the section has a reasonable size. */
if (size < 8 || size >= bfd_get_size (abfd))
if (size < 8 || (file_size != 0 && size >= file_size))
return NULL;
if (!bfd_malloc_and_get_section (abfd, sect, &contents))
@ -1298,6 +1300,7 @@ bfd_get_alt_debug_link_info (bfd * abfd, bfd_size_type *buildid_len,
unsigned int buildid_offset;
char *name;
bfd_size_type size;
ufile_ptr file_size;
BFD_ASSERT (abfd);
BFD_ASSERT (buildid_len);
@ -1309,7 +1312,8 @@ bfd_get_alt_debug_link_info (bfd * abfd, bfd_size_type *buildid_len,
return NULL;
size = bfd_section_size (sect);
if (size < 8 || size >= bfd_get_size (abfd))
file_size = bfd_get_size (abfd);
if (size < 8 || (file_size != 0 && size >= file_size))
return NULL;
if (!bfd_malloc_and_get_section (abfd, sect, & contents))