/* BFD library -- caching of file descriptors.
- Copyright 1990, 1991, 1992, 1993, 1994, 1996, 2000, 2001, 2002,
- 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 1990-2019 Free Software Foundation, Inc.
Hacked by Steve Chamberlain of Cygnus Support (steve@cygnus.com).
-This file is part of BFD, the Binary File Descriptor library.
+ 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 2 of the License, or
-(at your option) any later version.
+ 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.
+ 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. */
+ 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. */
/*
SECTION
regard to the underlying operating system's file descriptor
limit (often as low as 20 open files). The module in
<<cache.c>> maintains a least recently used list of
- <<BFD_CACHE_MAX_OPEN>> files, and exports the name
+ <<bfd_cache_max_open>> files, and exports the name
<<bfd_cache_lookup>>, which runs around and makes sure that
the required BFD is open. If not, then it chooses a file to
close, closes it and opens the one wanted, returning its file
Caching functions
*/
-#include "bfd.h"
#include "sysdep.h"
+#include "bfd.h"
#include "libbfd.h"
#include "libiberty.h"
-static bfd_boolean bfd_cache_delete (bfd *);
+#ifdef HAVE_MMAP
+#include <sys/mman.h>
+#endif
+
+/* In some cases we can optimize cache operation when reopening files.
+ For instance, a flush is entirely unnecessary if the file is already
+ closed, so a flush would use CACHE_NO_OPEN. Similarly, a seek using
+ SEEK_SET or SEEK_END need not first seek to the current position.
+ For stat we ignore seek errors, just in case the file has changed
+ while we weren't looking. If it has, then it's possible that the
+ file is shorter and we don't want a seek error to prevent us doing
+ the stat. */
+enum cache_flag {
+ CACHE_NORMAL = 0,
+ CACHE_NO_OPEN = 1,
+ CACHE_NO_SEEK = 2,
+ CACHE_NO_SEEK_ERROR = 4
+};
+
+/* The maximum number of files which the cache will keep open at
+ one time. When needed call bfd_cache_max_open to initialize. */
+
+static int max_open_files = 0;
+
+/* Set max_open_files, if not already set, to 12.5% of the allowed open
+ file descriptors, but at least 10, and return the value. */
+static int
+bfd_cache_max_open (void)
+{
+ if (max_open_files == 0)
+ {
+ int max;
+#if defined(__sun) && !defined(__sparcv9) && !defined(__x86_64__)
+ /* PR ld/19260: 32-bit Solaris has very inelegant handling of the 255
+ file descriptor limit. The problem is that setrlimit(2) can raise
+ RLIMIT_NOFILE to a value that is not supported by libc, resulting
+ in "Too many open files" errors. This can happen here even though
+ max_open_files is set to rlim.rlim_cur / 8. For example, if
+ a parent process has set rlim.rlim_cur to 65536, then max_open_files
+ will be computed as 8192.
+
+ This check essentially reverts to the behavior from binutils 2.23.1
+ for 32-bit Solaris only. (It is hoped that the 32-bit libc
+ limitation will be removed soon). 64-bit Solaris libc does not have
+ this limitation. */
+ max = 16;
+#else
+#ifdef HAVE_GETRLIMIT
+ struct rlimit rlim;
+
+ if (getrlimit (RLIMIT_NOFILE, &rlim) == 0
+ && rlim.rlim_cur != (rlim_t) RLIM_INFINITY)
+ max = rlim.rlim_cur / 8;
+ else
+#endif
+#ifdef _SC_OPEN_MAX
+ max = sysconf (_SC_OPEN_MAX) / 8;
+#else
+ max = 10;
+#endif
+#endif /* not 32-bit Solaris */
+
+ max_open_files = max < 10 ? 10 : max;
+ }
+
+ return max_open_files;
+}
+
+/* The number of BFD files we have open. */
+
+static int open_files;
+
+/* Zero, or a pointer to the topmost BFD on the chain. This is
+ used by the <<bfd_cache_lookup>> macro in @file{libbfd.h} to
+ determine when it can avoid a function call. */
+
+static bfd *bfd_last_cache = NULL;
+
+/* Insert a BFD into the cache. */
+
+static void
+insert (bfd *abfd)
+{
+ if (bfd_last_cache == NULL)
+ {
+ abfd->lru_next = abfd;
+ abfd->lru_prev = abfd;
+ }
+ else
+ {
+ abfd->lru_next = bfd_last_cache;
+ abfd->lru_prev = bfd_last_cache->lru_prev;
+ abfd->lru_prev->lru_next = abfd;
+ abfd->lru_next->lru_prev = abfd;
+ }
+ bfd_last_cache = abfd;
+}
+
+/* Remove a BFD from the cache. */
+
+static void
+snip (bfd *abfd)
+{
+ abfd->lru_prev->lru_next = abfd->lru_next;
+ abfd->lru_next->lru_prev = abfd->lru_prev;
+ if (abfd == bfd_last_cache)
+ {
+ bfd_last_cache = abfd->lru_next;
+ if (abfd == bfd_last_cache)
+ bfd_last_cache = NULL;
+ }
+}
+
+/* Close a BFD and remove it from the cache. */
+
+static bfd_boolean
+bfd_cache_delete (bfd *abfd)
+{
+ bfd_boolean ret;
+
+ if (fclose ((FILE *) abfd->iostream) == 0)
+ ret = TRUE;
+ else
+ {
+ ret = FALSE;
+ bfd_set_error (bfd_error_system_call);
+ }
+
+ snip (abfd);
+
+ abfd->iostream = NULL;
+ --open_files;
+
+ return ret;
+}
+
+/* We need to open a new file, and the cache is full. Find the least
+ recently used cacheable BFD and close it. */
+static bfd_boolean
+close_one (void)
+{
+ register bfd *to_kill;
+
+ if (bfd_last_cache == NULL)
+ to_kill = NULL;
+ else
+ {
+ for (to_kill = bfd_last_cache->lru_prev;
+ ! to_kill->cacheable;
+ to_kill = to_kill->lru_prev)
+ {
+ if (to_kill == bfd_last_cache)
+ {
+ to_kill = NULL;
+ break;
+ }
+ }
+ }
+
+ if (to_kill == NULL)
+ {
+ /* There are no open cacheable BFD's. */
+ return TRUE;
+ }
+
+ to_kill->where = _bfd_real_ftell ((FILE *) to_kill->iostream);
+
+ return bfd_cache_delete (to_kill);
+}
+
+/* Check to see if the required BFD is the same as the last one
+ looked up. If so, then it can use the stream in the BFD with
+ impunity, since it can't have changed since the last lookup;
+ otherwise, it has to perform the complicated lookup function. */
+
+#define bfd_cache_lookup(x, flag) \
+ ((x) == bfd_last_cache \
+ ? (FILE *) (bfd_last_cache->iostream) \
+ : bfd_cache_lookup_worker (x, flag))
+
+/* Called when the macro <<bfd_cache_lookup>> fails to find a
+ quick answer. Find a file descriptor for @var{abfd}. If
+ necessary, it open it. If there are already more than
+ <<bfd_cache_max_open>> files open, it tries to close one first, to
+ avoid running out of file descriptors. It will return NULL
+ if it is unable to (re)open the @var{abfd}. */
+
+static FILE *
+bfd_cache_lookup_worker (bfd *abfd, enum cache_flag flag)
+{
+ if ((abfd->flags & BFD_IN_MEMORY) != 0)
+ abort ();
+
+ if (abfd->my_archive != NULL
+ && !bfd_is_thin_archive (abfd->my_archive))
+ abort ();
+
+ if (abfd->iostream != NULL)
+ {
+ /* Move the file to the start of the cache. */
+ if (abfd != bfd_last_cache)
+ {
+ snip (abfd);
+ insert (abfd);
+ }
+ return (FILE *) abfd->iostream;
+ }
+
+ if (flag & CACHE_NO_OPEN)
+ return NULL;
+
+ if (bfd_open_file (abfd) == NULL)
+ ;
+ else if (!(flag & CACHE_NO_SEEK)
+ && _bfd_real_fseek ((FILE *) abfd->iostream,
+ abfd->where, SEEK_SET) != 0
+ && !(flag & CACHE_NO_SEEK_ERROR))
+ bfd_set_error (bfd_error_system_call);
+ else
+ return (FILE *) abfd->iostream;
+
+ /* xgettext:c-format */
+ _bfd_error_handler (_("reopening %pB: %s\n"),
+ abfd, bfd_errmsg (bfd_get_error ()));
+ return NULL;
+}
static file_ptr
cache_btell (struct bfd *abfd)
{
- FILE *f = bfd_cache_lookup (abfd);
+ FILE *f = bfd_cache_lookup (abfd, CACHE_NO_OPEN);
if (f == NULL)
- return -1;
- return real_ftell (f);
+ return abfd->where;
+ return _bfd_real_ftell (f);
}
static int
cache_bseek (struct bfd *abfd, file_ptr offset, int whence)
{
- FILE *f = bfd_cache_lookup (abfd);
+ FILE *f = bfd_cache_lookup (abfd, whence != SEEK_CUR ? CACHE_NO_SEEK : CACHE_NORMAL);
if (f == NULL)
return -1;
- return real_fseek (f, offset, whence);
+ return _bfd_real_fseek (f, offset, whence);
}
/* Note that archive entries don't have streams; they share their parent's.
first octet in the file, NOT the beginning of the archive header. */
static file_ptr
-cache_bread (struct bfd *abfd, void *buf, file_ptr nbytes)
+cache_bread_1 (FILE *f, void *buf, file_ptr nbytes)
{
- FILE *f;
file_ptr nread;
- /* FIXME - this looks like an optimization, but it's really to cover
- up for a feature of some OSs (not solaris - sigh) that
- ld/pe-dll.c takes advantage of (apparently) when it creates BFDs
- internally and tries to link against them. BFD seems to be smart
- enough to realize there are no symbol records in the "file" that
- doesn't exist but attempts to read them anyway. On Solaris,
- attempting to read zero bytes from a NULL file results in a core
- dump, but on other platforms it just returns zero bytes read.
- This makes it to something reasonable. - DJ */
- if (nbytes == 0)
- return 0;
-
- f = bfd_cache_lookup (abfd);
- if (f == NULL)
- return 0;
#if defined (__VAX) && defined (VMS)
/* Apparently fread on Vax VMS does not keep the record length
if (nread == (file_ptr)-1)
{
bfd_set_error (bfd_error_system_call);
- return -1;
+ return nread;
}
#else
nread = fread (buf, 1, nbytes, f);
if (nread < nbytes && ferror (f))
{
bfd_set_error (bfd_error_system_call);
- return -1;
+ return nread;
}
#endif
+ if (nread < nbytes)
+ /* This may or may not be an error, but in case the calling code
+ bails out because of it, set the right error code. */
+ bfd_set_error (bfd_error_file_truncated);
+ return nread;
+}
+
+static file_ptr
+cache_bread (struct bfd *abfd, void *buf, file_ptr nbytes)
+{
+ file_ptr nread = 0;
+ FILE *f;
+
+ f = bfd_cache_lookup (abfd, CACHE_NORMAL);
+ if (f == NULL)
+ return -1;
+
+ /* Some filesystems are unable to handle reads that are too large
+ (for instance, NetApp shares with oplocks turned off). To avoid
+ hitting this limitation, we read the buffer in chunks of 8MB max. */
+ while (nread < nbytes)
+ {
+ const file_ptr max_chunk_size = 0x800000;
+ file_ptr chunk_size = nbytes - nread;
+ file_ptr chunk_nread;
+
+ if (chunk_size > max_chunk_size)
+ chunk_size = max_chunk_size;
+
+ chunk_nread = cache_bread_1 (f, (char *) buf + nread, chunk_size);
+
+ /* Update the nread count.
+
+ We just have to be careful of the case when cache_bread_1 returns
+ a negative count: If this is our first read, then set nread to
+ that negative count in order to return that negative value to the
+ caller. Otherwise, don't add it to our total count, or we would
+ end up returning a smaller number of bytes read than we actually
+ did. */
+ if (nread == 0 || chunk_nread > 0)
+ nread += chunk_nread;
+
+ if (chunk_nread < chunk_size)
+ break;
+ }
+
return nread;
}
static file_ptr
-cache_bwrite (struct bfd *abfd, const void *where, file_ptr nbytes)
+cache_bwrite (struct bfd *abfd, const void *from, file_ptr nbytes)
{
file_ptr nwrite;
- FILE *f = bfd_cache_lookup (abfd);
+ FILE *f = bfd_cache_lookup (abfd, CACHE_NORMAL);
+
if (f == NULL)
return 0;
- nwrite = fwrite (where, 1, nbytes, f);
+ nwrite = fwrite (from, 1, nbytes, f);
if (nwrite < nbytes && ferror (f))
{
bfd_set_error (bfd_error_system_call);
static int
cache_bclose (struct bfd *abfd)
{
- return bfd_cache_close (abfd);
+ return bfd_cache_close (abfd) - 1;
}
static int
cache_bflush (struct bfd *abfd)
{
int sts;
- FILE *f = bfd_cache_lookup (abfd);
+ FILE *f = bfd_cache_lookup (abfd, CACHE_NO_OPEN);
+
if (f == NULL)
- return -1;
+ return 0;
sts = fflush (f);
if (sts < 0)
bfd_set_error (bfd_error_system_call);
cache_bstat (struct bfd *abfd, struct stat *sb)
{
int sts;
- FILE *f = bfd_cache_lookup (abfd);
+ FILE *f = bfd_cache_lookup (abfd, CACHE_NO_SEEK_ERROR);
+
if (f == NULL)
return -1;
sts = fstat (fileno (f), sb);
return sts;
}
-static const struct bfd_iovec cache_iovec = {
- &cache_bread, &cache_bwrite, &cache_btell, &cache_bseek,
- &cache_bclose, &cache_bflush, &cache_bstat
-};
-
-/*
-INTERNAL_FUNCTION
- BFD_CACHE_MAX_OPEN macro
-
-DESCRIPTION
- The maximum number of files which the cache will keep open at
- one time.
-
-.#define BFD_CACHE_MAX_OPEN 10
-
-*/
-
-/* The number of BFD files we have open. */
-
-static int open_files;
-
-/*
-INTERNAL_FUNCTION
- bfd_last_cache
-
-SYNOPSIS
- extern bfd *bfd_last_cache;
-
-DESCRIPTION
- Zero, or a pointer to the topmost BFD on the chain. This is
- used by the <<bfd_cache_lookup>> macro in @file{libbfd.h} to
- determine when it can avoid a function call.
-*/
-
-bfd *bfd_last_cache = NULL;
-
-/*
- INTERNAL_FUNCTION
- bfd_cache_lookup
-
- DESCRIPTION
- Check to see if the required BFD is the same as the last one
- looked up. If so, then it can use the stream in the BFD with
- impunity, since it can't have changed since the last lookup;
- otherwise, it has to perform the complicated lookup function.
-
- .#define bfd_cache_lookup(x) \
- . ((x) == bfd_last_cache ? \
- . (FILE *) (bfd_last_cache->iostream): \
- . bfd_cache_lookup_worker (x))
-
- */
-
-/* Insert a BFD into the cache. */
-
-static void
-insert (bfd *abfd)
+static void *
+cache_bmmap (struct bfd *abfd ATTRIBUTE_UNUSED,
+ void *addr ATTRIBUTE_UNUSED,
+ bfd_size_type len ATTRIBUTE_UNUSED,
+ int prot ATTRIBUTE_UNUSED,
+ int flags ATTRIBUTE_UNUSED,
+ file_ptr offset ATTRIBUTE_UNUSED,
+ void **map_addr ATTRIBUTE_UNUSED,
+ bfd_size_type *map_len ATTRIBUTE_UNUSED)
{
- if (bfd_last_cache == NULL)
- {
- abfd->lru_next = abfd;
- abfd->lru_prev = abfd;
- }
+ void *ret = (void *) -1;
+
+ if ((abfd->flags & BFD_IN_MEMORY) != 0)
+ abort ();
+#ifdef HAVE_MMAP
else
{
- abfd->lru_next = bfd_last_cache;
- abfd->lru_prev = bfd_last_cache->lru_prev;
- abfd->lru_prev->lru_next = abfd;
- abfd->lru_next->lru_prev = abfd;
- }
- bfd_last_cache = abfd;
-}
+ static uintptr_t pagesize_m1;
+ FILE *f;
+ file_ptr pg_offset;
+ bfd_size_type pg_len;
-/* Remove a BFD from the cache. */
-
-static void
-snip (bfd *abfd)
-{
- abfd->lru_prev->lru_next = abfd->lru_next;
- abfd->lru_next->lru_prev = abfd->lru_prev;
- if (abfd == bfd_last_cache)
- {
- bfd_last_cache = abfd->lru_next;
- if (abfd == bfd_last_cache)
- bfd_last_cache = NULL;
- }
-}
+ f = bfd_cache_lookup (abfd, CACHE_NO_SEEK_ERROR);
+ if (f == NULL)
+ return ret;
-/* We need to open a new file, and the cache is full. Find the least
- recently used cacheable BFD and close it. */
+ if (pagesize_m1 == 0)
+ pagesize_m1 = getpagesize () - 1;
-static bfd_boolean
-close_one (void)
-{
- register bfd *kill;
+ /* Align. */
+ pg_offset = offset & ~pagesize_m1;
+ pg_len = (len + (offset - pg_offset) + pagesize_m1) & ~pagesize_m1;
- if (bfd_last_cache == NULL)
- kill = NULL;
- else
- {
- for (kill = bfd_last_cache->lru_prev;
- ! kill->cacheable;
- kill = kill->lru_prev)
+ ret = mmap (addr, pg_len, prot, flags, fileno (f), pg_offset);
+ if (ret == (void *) -1)
+ bfd_set_error (bfd_error_system_call);
+ else
{
- if (kill == bfd_last_cache)
- {
- kill = NULL;
- break;
- }
+ *map_addr = ret;
+ *map_len = pg_len;
+ ret = (char *) ret + (offset & pagesize_m1);
}
}
+#endif
- if (kill == NULL)
- {
- /* There are no open cacheable BFD's. */
- return TRUE;
- }
-
- kill->where = real_ftell ((FILE *) kill->iostream);
-
- return bfd_cache_delete (kill);
+ return ret;
}
-/* Close a BFD and remove it from the cache. */
-
-static bfd_boolean
-bfd_cache_delete (bfd *abfd)
+static const struct bfd_iovec cache_iovec =
{
- bfd_boolean ret;
-
- if (fclose ((FILE *) abfd->iostream) == 0)
- ret = TRUE;
- else
- {
- ret = FALSE;
- bfd_set_error (bfd_error_system_call);
- }
-
- snip (abfd);
-
- abfd->iostream = NULL;
- --open_files;
-
- return ret;
-}
+ &cache_bread, &cache_bwrite, &cache_btell, &cache_bseek,
+ &cache_bclose, &cache_bflush, &cache_bstat, &cache_bmmap
+};
/*
INTERNAL_FUNCTION
bfd_cache_init (bfd *abfd)
{
BFD_ASSERT (abfd->iostream != NULL);
- if (open_files >= BFD_CACHE_MAX_OPEN)
+ if (open_files >= bfd_cache_max_open ())
{
if (! close_one ())
return FALSE;
*/
bfd_boolean
-bfd_cache_close_all ()
+bfd_cache_close_all (void)
{
bfd_boolean ret = TRUE;
{
abfd->cacheable = TRUE; /* Allow it to be closed later. */
- if (open_files >= BFD_CACHE_MAX_OPEN)
+ if (open_files >= bfd_cache_max_open ())
{
if (! close_one ())
return NULL;
{
case read_direction:
case no_direction:
- abfd->iostream = (PTR) fopen (abfd->filename, FOPEN_RB);
+ abfd->iostream = _bfd_real_fopen (abfd->filename, FOPEN_RB);
break;
case both_direction:
case write_direction:
if (abfd->opened_once)
{
- abfd->iostream = (PTR) fopen (abfd->filename, FOPEN_RUB);
+ abfd->iostream = _bfd_real_fopen (abfd->filename, FOPEN_RUB);
if (abfd->iostream == NULL)
- abfd->iostream = (PTR) fopen (abfd->filename, FOPEN_WUB);
+ abfd->iostream = _bfd_real_fopen (abfd->filename, FOPEN_WUB);
}
else
{
if (stat (abfd->filename, &s) == 0 && s.st_size != 0)
unlink_if_ordinary (abfd->filename);
#endif
- abfd->iostream = (PTR) fopen (abfd->filename, FOPEN_WUB);
+ abfd->iostream = _bfd_real_fopen (abfd->filename, FOPEN_WUB);
abfd->opened_once = TRUE;
}
break;
return (FILE *) abfd->iostream;
}
-
-/*
-INTERNAL_FUNCTION
- bfd_cache_lookup_worker
-
-SYNOPSIS
- FILE *bfd_cache_lookup_worker (bfd *abfd);
-
-DESCRIPTION
- Called when the macro <<bfd_cache_lookup>> fails to find a
- quick answer. Find a file descriptor for @var{abfd}. If
- necessary, it open it. If there are already more than
- <<BFD_CACHE_MAX_OPEN>> files open, it tries to close one first, to
- avoid running out of file descriptors. It will return NULL
- if it is unable to (re)open the @var{abfd}.
-*/
-
-FILE *
-bfd_cache_lookup_worker (bfd *abfd)
-{
- bfd *orig_bfd = abfd;
- if ((abfd->flags & BFD_IN_MEMORY) != 0)
- abort ();
-
- if (abfd->my_archive)
- abfd = abfd->my_archive;
-
- if (abfd->iostream != NULL)
- {
- /* Move the file to the start of the cache. */
- if (abfd != bfd_last_cache)
- {
- snip (abfd);
- insert (abfd);
- }
- return (FILE *) abfd->iostream;
- }
-
- if (bfd_open_file (abfd) == NULL)
- ;
- else if (real_fseek ((FILE *) abfd->iostream, abfd->where, SEEK_SET) != 0)
- bfd_set_error (bfd_error_system_call);
- else
- return (FILE *) abfd->iostream;
-
- (*_bfd_error_handler) (_("reopening %B: %s\n"),
- orig_bfd, bfd_errmsg (bfd_get_error ()));
- return NULL;
-}