| /* Definitions for BFD wrappers used by GDB. |
| |
| Copyright (C) 2011, 2012 |
| 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 "defs.h" |
| #include "gdb_bfd.h" |
| #include "gdb_assert.h" |
| #include "gdb_string.h" |
| #include "ui-out.h" |
| #include "gdbcmd.h" |
| #include "hashtab.h" |
| #ifdef HAVE_ZLIB_H |
| #include <zlib.h> |
| #endif |
| #ifdef HAVE_MMAP |
| #include <sys/mman.h> |
| #ifndef MAP_FAILED |
| #define MAP_FAILED ((void *) -1) |
| #endif |
| #endif |
| |
| /* An object of this type is stored in the section's user data when |
| mapping a section. */ |
| |
| struct gdb_bfd_section_data |
| { |
| /* Size of the data. */ |
| bfd_size_type size; |
| /* If the data was mmapped, this is the length of the map. */ |
| bfd_size_type map_len; |
| /* The data. If NULL, the section data has not been read. */ |
| void *data; |
| /* If the data was mmapped, this is the map address. */ |
| void *map_addr; |
| }; |
| |
| /* A hash table holding every BFD that gdb knows about. This is not |
| to be confused with 'gdb_bfd_cache', which is used for sharing |
| BFDs; in contrast, this hash is used just to implement |
| "maint info bfd". */ |
| |
| static htab_t all_bfds; |
| |
| /* See gdb_bfd.h. */ |
| |
| void |
| gdb_bfd_stash_filename (struct bfd *abfd) |
| { |
| char *name = bfd_get_filename (abfd); |
| char *data; |
| |
| data = bfd_alloc (abfd, strlen (name) + 1); |
| strcpy (data, name); |
| |
| /* Unwarranted chumminess with BFD. */ |
| abfd->filename = data; |
| } |
| |
| /* An object of this type is stored in each BFD's user data. */ |
| |
| struct gdb_bfd_data |
| { |
| /* The reference count. */ |
| int refc; |
| |
| /* The mtime of the BFD at the point the cache entry was made. */ |
| time_t mtime; |
| }; |
| |
| /* A hash table storing all the BFDs maintained in the cache. */ |
| |
| static htab_t gdb_bfd_cache; |
| |
| /* The type of an object being looked up in gdb_bfd_cache. We use |
| htab's capability of storing one kind of object (BFD in this case) |
| and using a different sort of object for searching. */ |
| |
| struct gdb_bfd_cache_search |
| { |
| /* The filename. */ |
| const char *filename; |
| /* The mtime. */ |
| time_t mtime; |
| }; |
| |
| /* A hash function for BFDs. */ |
| |
| static hashval_t |
| hash_bfd (const void *b) |
| { |
| const bfd *abfd = b; |
| |
| /* It is simplest to just hash the filename. */ |
| return htab_hash_string (bfd_get_filename (abfd)); |
| } |
| |
| /* An equality function for BFDs. Note that this expects the caller |
| to search using struct gdb_bfd_cache_search only, not BFDs. */ |
| |
| static int |
| eq_bfd (const void *a, const void *b) |
| { |
| const bfd *abfd = a; |
| const struct gdb_bfd_cache_search *s = b; |
| struct gdb_bfd_data *gdata = bfd_usrdata (abfd); |
| |
| return (gdata->mtime == s->mtime |
| && strcmp (bfd_get_filename (abfd), s->filename) == 0); |
| } |
| |
| /* See gdb_bfd.h. */ |
| |
| struct bfd * |
| gdb_bfd_open (const char *name, const char *target, int fd) |
| { |
| hashval_t hash; |
| void **slot; |
| bfd *abfd; |
| struct gdb_bfd_cache_search search; |
| struct stat st; |
| |
| if (gdb_bfd_cache == NULL) |
| gdb_bfd_cache = htab_create_alloc (1, hash_bfd, eq_bfd, NULL, |
| xcalloc, xfree); |
| |
| if (fd == -1) |
| { |
| fd = open (name, O_RDONLY | O_BINARY); |
| if (fd == -1) |
| { |
| bfd_set_error (bfd_error_system_call); |
| return NULL; |
| } |
| } |
| |
| search.filename = name; |
| if (fstat (fd, &st) < 0) |
| { |
| /* Weird situation here. */ |
| search.mtime = 0; |
| } |
| else |
| search.mtime = st.st_mtime; |
| |
| /* Note that this must compute the same result as hash_bfd. */ |
| hash = htab_hash_string (name); |
| /* Note that we cannot use htab_find_slot_with_hash here, because |
| opening the BFD may fail; and this would violate hashtab |
| invariants. */ |
| abfd = htab_find_with_hash (gdb_bfd_cache, &search, hash); |
| if (abfd != NULL) |
| { |
| close (fd); |
| gdb_bfd_ref (abfd); |
| return abfd; |
| } |
| |
| abfd = bfd_fopen (name, target, FOPEN_RB, fd); |
| if (abfd == NULL) |
| return NULL; |
| |
| slot = htab_find_slot_with_hash (gdb_bfd_cache, &search, hash, INSERT); |
| gdb_assert (!*slot); |
| *slot = abfd; |
| |
| gdb_bfd_stash_filename (abfd); |
| gdb_bfd_ref (abfd); |
| return abfd; |
| } |
| |
| /* A helper function that releases any section data attached to the |
| BFD. */ |
| |
| static void |
| free_one_bfd_section (bfd *abfd, asection *sectp, void *ignore) |
| { |
| struct gdb_bfd_section_data *sect = bfd_get_section_userdata (abfd, sectp); |
| |
| if (sect != NULL && sect->data != NULL) |
| { |
| #ifdef HAVE_MMAP |
| if (sect->map_addr != NULL) |
| { |
| int res; |
| |
| res = munmap (sect->map_addr, sect->map_len); |
| gdb_assert (res == 0); |
| } |
| else |
| #endif |
| xfree (sect->data); |
| } |
| } |
| |
| /* Close ABFD, and warn if that fails. */ |
| |
| static int |
| gdb_bfd_close_or_warn (struct bfd *abfd) |
| { |
| int ret; |
| char *name = bfd_get_filename (abfd); |
| |
| bfd_map_over_sections (abfd, free_one_bfd_section, NULL); |
| |
| ret = bfd_close (abfd); |
| |
| if (!ret) |
| warning (_("cannot close \"%s\": %s"), |
| name, bfd_errmsg (bfd_get_error ())); |
| |
| return ret; |
| } |
| |
| /* See gdb_bfd.h. */ |
| |
| void |
| gdb_bfd_ref (struct bfd *abfd) |
| { |
| struct gdb_bfd_data *gdata; |
| void **slot; |
| |
| if (abfd == NULL) |
| return; |
| |
| gdata = bfd_usrdata (abfd); |
| |
| if (gdata != NULL) |
| { |
| gdata->refc += 1; |
| return; |
| } |
| |
| gdata = bfd_zalloc (abfd, sizeof (struct gdb_bfd_data)); |
| gdata->refc = 1; |
| gdata->mtime = bfd_get_mtime (abfd); |
| bfd_usrdata (abfd) = gdata; |
| |
| /* This is the first we've seen it, so add it to the hash table. */ |
| slot = htab_find_slot (all_bfds, abfd, INSERT); |
| gdb_assert (slot && !*slot); |
| *slot = abfd; |
| } |
| |
| /* See gdb_bfd.h. */ |
| |
| void |
| gdb_bfd_unref (struct bfd *abfd) |
| { |
| struct gdb_bfd_data *gdata; |
| struct gdb_bfd_cache_search search; |
| void **slot; |
| |
| if (abfd == NULL) |
| return; |
| |
| gdata = bfd_usrdata (abfd); |
| gdb_assert (gdata->refc >= 1); |
| |
| gdata->refc -= 1; |
| if (gdata->refc > 0) |
| return; |
| |
| search.filename = bfd_get_filename (abfd); |
| |
| if (gdb_bfd_cache && search.filename) |
| { |
| hashval_t hash = htab_hash_string (search.filename); |
| void **slot; |
| |
| search.mtime = gdata->mtime; |
| slot = htab_find_slot_with_hash (gdb_bfd_cache, &search, hash, |
| NO_INSERT); |
| |
| if (slot && *slot) |
| htab_clear_slot (gdb_bfd_cache, slot); |
| } |
| |
| bfd_usrdata (abfd) = NULL; /* Paranoia. */ |
| |
| htab_remove_elt (all_bfds, abfd); |
| |
| gdb_bfd_close_or_warn (abfd); |
| } |
| |
| /* A helper function that returns the section data descriptor |
| associated with SECTION. If no such descriptor exists, a new one |
| is allocated and cleared. */ |
| |
| static struct gdb_bfd_section_data * |
| get_section_descriptor (asection *section) |
| { |
| struct gdb_bfd_section_data *result; |
| |
| result = bfd_get_section_userdata (section->owner, section); |
| |
| if (result == NULL) |
| { |
| result = bfd_zalloc (section->owner, sizeof (*result)); |
| bfd_set_section_userdata (section->owner, section, result); |
| } |
| |
| return result; |
| } |
| |
| /* Decompress a section that was compressed using zlib. Store the |
| decompressed buffer, and its size, in DESCRIPTOR. */ |
| |
| static void |
| zlib_decompress_section (asection *sectp, |
| struct gdb_bfd_section_data *descriptor) |
| { |
| bfd *abfd = sectp->owner; |
| #ifndef HAVE_ZLIB_H |
| error (_("Support for zlib-compressed data (from '%s', section '%s') " |
| "is disabled in this copy of GDB"), |
| bfd_get_filename (abfd), |
| bfd_get_section_name (abfd, sectp)); |
| #else |
| bfd_size_type compressed_size = bfd_get_section_size (sectp); |
| gdb_byte *compressed_buffer = xmalloc (compressed_size); |
| struct cleanup *cleanup = make_cleanup (xfree, compressed_buffer); |
| struct cleanup *inner_cleanup; |
| bfd_size_type uncompressed_size; |
| gdb_byte *uncompressed_buffer; |
| z_stream strm; |
| int rc; |
| int header_size = 12; |
| struct dwarf2_per_bfd_section *section_data; |
| |
| if (bfd_seek (abfd, sectp->filepos, SEEK_SET) != 0 |
| || bfd_bread (compressed_buffer, |
| compressed_size, abfd) != compressed_size) |
| error (_("can't read data from '%s', section '%s'"), |
| bfd_get_filename (abfd), |
| bfd_get_section_name (abfd, sectp)); |
| |
| /* Read the zlib header. In this case, it should be "ZLIB" followed |
| by the uncompressed section size, 8 bytes in big-endian order. */ |
| if (compressed_size < header_size |
| || strncmp (compressed_buffer, "ZLIB", 4) != 0) |
| error (_("corrupt ZLIB header from '%s', section '%s'"), |
| bfd_get_filename (abfd), |
| bfd_get_section_name (abfd, sectp)); |
| uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8; |
| uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8; |
| uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8; |
| uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8; |
| uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8; |
| uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8; |
| uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8; |
| uncompressed_size += compressed_buffer[11]; |
| |
| /* It is possible the section consists of several compressed |
| buffers concatenated together, so we uncompress in a loop. */ |
| strm.zalloc = NULL; |
| strm.zfree = NULL; |
| strm.opaque = NULL; |
| strm.avail_in = compressed_size - header_size; |
| strm.next_in = (Bytef*) compressed_buffer + header_size; |
| strm.avail_out = uncompressed_size; |
| uncompressed_buffer = xmalloc (uncompressed_size); |
| inner_cleanup = make_cleanup (xfree, uncompressed_buffer); |
| rc = inflateInit (&strm); |
| while (strm.avail_in > 0) |
| { |
| if (rc != Z_OK) |
| error (_("setting up uncompression in '%s', section '%s': %d"), |
| bfd_get_filename (abfd), |
| bfd_get_section_name (abfd, sectp), |
| rc); |
| strm.next_out = ((Bytef*) uncompressed_buffer |
| + (uncompressed_size - strm.avail_out)); |
| rc = inflate (&strm, Z_FINISH); |
| if (rc != Z_STREAM_END) |
| error (_("zlib error uncompressing from '%s', section '%s': %d"), |
| bfd_get_filename (abfd), |
| bfd_get_section_name (abfd, sectp), |
| rc); |
| rc = inflateReset (&strm); |
| } |
| rc = inflateEnd (&strm); |
| if (rc != Z_OK |
| || strm.avail_out != 0) |
| error (_("concluding uncompression in '%s', section '%s': %d"), |
| bfd_get_filename (abfd), |
| bfd_get_section_name (abfd, sectp), |
| rc); |
| |
| discard_cleanups (inner_cleanup); |
| do_cleanups (cleanup); |
| |
| /* Attach the data to the BFD section. */ |
| descriptor->data = uncompressed_buffer; |
| descriptor->size = uncompressed_size; |
| #endif |
| } |
| |
| /* See gdb_bfd.h. */ |
| |
| const gdb_byte * |
| gdb_bfd_map_section (asection *sectp, bfd_size_type *size) |
| { |
| bfd *abfd; |
| gdb_byte *buf, *retbuf; |
| unsigned char header[4]; |
| struct gdb_bfd_section_data *descriptor; |
| |
| gdb_assert ((sectp->flags & SEC_RELOC) == 0); |
| gdb_assert (size != NULL); |
| |
| abfd = sectp->owner; |
| |
| descriptor = get_section_descriptor (sectp); |
| |
| /* If the data was already read for this BFD, just reuse it. */ |
| if (descriptor->data != NULL) |
| goto done; |
| |
| /* Check if the file has a 4-byte header indicating compression. */ |
| if (bfd_get_section_size (sectp) > sizeof (header) |
| && bfd_seek (abfd, sectp->filepos, SEEK_SET) == 0 |
| && bfd_bread (header, sizeof (header), abfd) == sizeof (header)) |
| { |
| /* Upon decompression, update the buffer and its size. */ |
| if (strncmp (header, "ZLIB", sizeof (header)) == 0) |
| { |
| zlib_decompress_section (sectp, descriptor); |
| goto done; |
| } |
| } |
| |
| #ifdef HAVE_MMAP |
| { |
| /* The page size, used when mmapping. */ |
| static int pagesize; |
| |
| if (pagesize == 0) |
| pagesize = getpagesize (); |
| |
| /* Only try to mmap sections which are large enough: we don't want |
| to waste space due to fragmentation. */ |
| |
| if (bfd_get_section_size (sectp) > 4 * pagesize) |
| { |
| descriptor->size = bfd_get_section_size (sectp); |
| descriptor->data = bfd_mmap (abfd, 0, descriptor->size, PROT_READ, |
| MAP_PRIVATE, sectp->filepos, |
| &descriptor->map_addr, |
| &descriptor->map_len); |
| |
| if ((caddr_t)descriptor->data != MAP_FAILED) |
| { |
| #if HAVE_POSIX_MADVISE |
| posix_madvise (descriptor->map_addr, descriptor->map_len, |
| POSIX_MADV_WILLNEED); |
| #endif |
| goto done; |
| } |
| |
| /* On failure, clear out the section data and try again. */ |
| memset (descriptor, 0, sizeof (*descriptor)); |
| } |
| } |
| #endif /* HAVE_MMAP */ |
| |
| /* If we get here, we are a normal, not-compressed section. */ |
| |
| descriptor->size = bfd_get_section_size (sectp); |
| descriptor->data = xmalloc (descriptor->size); |
| |
| if (bfd_seek (abfd, sectp->filepos, SEEK_SET) != 0 |
| || bfd_bread (descriptor->data, bfd_get_section_size (sectp), |
| abfd) != bfd_get_section_size (sectp)) |
| { |
| xfree (descriptor->data); |
| descriptor->data = NULL; |
| error (_("Can't read data for section '%s'"), |
| bfd_get_filename (abfd)); |
| } |
| |
| done: |
| gdb_assert (descriptor->data != NULL); |
| *size = descriptor->size; |
| return descriptor->data; |
| } |
| |
| |
| |
| /* See gdb_bfd.h. */ |
| |
| bfd * |
| gdb_bfd_fopen (const char *filename, const char *target, const char *mode, |
| int fd) |
| { |
| bfd *result = bfd_fopen (filename, target, mode, fd); |
| |
| if (result) |
| { |
| gdb_bfd_stash_filename (result); |
| gdb_bfd_ref (result); |
| } |
| |
| return result; |
| } |
| |
| /* See gdb_bfd.h. */ |
| |
| bfd * |
| gdb_bfd_openr (const char *filename, const char *target) |
| { |
| bfd *result = bfd_openr (filename, target); |
| |
| if (result) |
| { |
| gdb_bfd_stash_filename (result); |
| gdb_bfd_ref (result); |
| } |
| |
| return result; |
| } |
| |
| /* See gdb_bfd.h. */ |
| |
| bfd * |
| gdb_bfd_openw (const char *filename, const char *target) |
| { |
| bfd *result = bfd_openw (filename, target); |
| |
| if (result) |
| { |
| gdb_bfd_stash_filename (result); |
| gdb_bfd_ref (result); |
| } |
| |
| return result; |
| } |
| |
| /* See gdb_bfd.h. */ |
| |
| bfd * |
| gdb_bfd_openr_iovec (const char *filename, const char *target, |
| void *(*open_func) (struct bfd *nbfd, |
| void *open_closure), |
| void *open_closure, |
| file_ptr (*pread_func) (struct bfd *nbfd, |
| void *stream, |
| void *buf, |
| file_ptr nbytes, |
| file_ptr offset), |
| int (*close_func) (struct bfd *nbfd, |
| void *stream), |
| int (*stat_func) (struct bfd *abfd, |
| void *stream, |
| struct stat *sb)) |
| { |
| bfd *result = bfd_openr_iovec (filename, target, |
| open_func, open_closure, |
| pread_func, close_func, stat_func); |
| |
| if (result) |
| { |
| gdb_bfd_ref (result); |
| gdb_bfd_stash_filename (result); |
| } |
| |
| return result; |
| } |
| |
| /* See gdb_bfd.h. */ |
| |
| bfd * |
| gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous) |
| { |
| bfd *result = bfd_openr_next_archived_file (archive, previous); |
| |
| if (result) |
| { |
| gdb_bfd_ref (result); |
| /* No need to stash the filename here. */ |
| } |
| |
| return result; |
| } |
| |
| /* See gdb_bfd.h. */ |
| |
| bfd * |
| gdb_bfd_fdopenr (const char *filename, const char *target, int fd) |
| { |
| bfd *result = bfd_fdopenr (filename, target, fd); |
| |
| if (result) |
| { |
| gdb_bfd_ref (result); |
| gdb_bfd_stash_filename (result); |
| } |
| |
| return result; |
| } |
| |
| |
| |
| /* A callback for htab_traverse that prints a single BFD. */ |
| |
| static int |
| print_one_bfd (void **slot, void *data) |
| { |
| bfd *abfd = *slot; |
| struct gdb_bfd_data *gdata = bfd_usrdata (abfd); |
| struct ui_out *uiout = data; |
| struct cleanup *inner; |
| |
| inner = make_cleanup_ui_out_tuple_begin_end (uiout, NULL); |
| ui_out_field_int (uiout, "refcount", gdata->refc); |
| ui_out_field_string (uiout, "addr", host_address_to_string (abfd)); |
| ui_out_field_string (uiout, "filename", bfd_get_filename (abfd)); |
| ui_out_text (uiout, "\n"); |
| do_cleanups (inner); |
| |
| return 1; |
| } |
| |
| /* Implement the 'maint info bfd' command. */ |
| |
| static void |
| maintenance_info_bfds (char *arg, int from_tty) |
| { |
| struct cleanup *cleanup; |
| struct ui_out *uiout = current_uiout; |
| |
| cleanup = make_cleanup_ui_out_table_begin_end (uiout, 3, -1, "bfds"); |
| ui_out_table_header (uiout, 10, ui_left, "refcount", "Refcount"); |
| ui_out_table_header (uiout, 18, ui_left, "addr", "Address"); |
| ui_out_table_header (uiout, 40, ui_left, "filename", "Filename"); |
| |
| ui_out_table_body (uiout); |
| htab_traverse (all_bfds, print_one_bfd, uiout); |
| |
| do_cleanups (cleanup); |
| } |
| |
| /* -Wmissing-prototypes */ |
| extern initialize_file_ftype _initialize_gdb_bfd; |
| |
| void |
| _initialize_gdb_bfd (void) |
| { |
| all_bfds = htab_create_alloc (10, htab_hash_pointer, htab_eq_pointer, |
| NULL, xcalloc, xfree); |
| |
| add_cmd ("bfds", class_maintenance, maintenance_info_bfds, _("\ |
| List the BFDs that are currently open."), |
| &maintenanceinfolist); |
| } |