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| author | Alan Modra <amodra@gmail.com> | 2018-06-05 21:04:00 +0930 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2018-06-05 22:39:11 +0930 |
| commit | 27b0767593284f97384b3597ebd211164f8c8b47 (patch) | |
| tree | 1f82c304a2abc2acca2d865190b382e0963cd84a /bfd | |
| parent | 8347745522002d5c0093bac584a2eaf9386ad219 (diff) | |
| download | gdb-27b0767593284f97384b3597ebd211164f8c8b47.zip gdb-27b0767593284f97384b3597ebd211164f8c8b47.tar.gz gdb-27b0767593284f97384b3597ebd211164f8c8b47.tar.bz2 | |
PR23254, ld.bfd mishandles file pointers while scanning archive
Best practice is to not mix lseek/read with fseek/fread on the same
underlying file descriptor, as not all stdio implementations will cope.
Since the plugin uses lseek/read while bfd uses fseek/fread this patch
reopens the file for exclusive use by the plugin rather than trying to
restore the file descriptor. That allows the plugin to read the file
after plugin_call_claim_file too.
bfd/
PR 23254
* plugin.c (bfd_plugin_open_input): Allow for possibility of
nested archives. Open file again for plugin.
(try_claim): Don't save and restore file position. Close file
if not claimed.
* sysdep.h (O_BINARY): Define.
ld/
PR 23254
* plugin.c (plugin_call_claim_file): Revert 2016-07-19 patch.
(plugin_object_p): Don't dup file descriptor.
Diffstat (limited to 'bfd')
| -rw-r--r-- | bfd/ChangeLog | 9 | ||||
| -rw-r--r-- | bfd/plugin.c | 20 | ||||
| -rw-r--r-- | bfd/sysdep.h | 4 |
3 files changed, 27 insertions, 6 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index d776d0b..3688cf2 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,12 @@ +2018-06-05 Alan Modra <amodra@gmail.com> + + PR 23254 + * plugin.c (bfd_plugin_open_input): Allow for possibility of + nested archives. Open file again for plugin. + (try_claim): Don't save and restore file position. Close file + if not claimed. + * sysdep.h (O_BINARY): Define. + 2018-06-04 Max Filippov <jcmvbkbc@gmail.com> * elf32-xtensa.c (xtensa_read_table_entries): Make global. diff --git a/bfd/plugin.c b/bfd/plugin.c index 16a706a..7c5bba2 100644 --- a/bfd/plugin.c +++ b/bfd/plugin.c @@ -166,14 +166,22 @@ bfd_plugin_open_input (bfd *ibfd, struct ld_plugin_input_file *file) bfd *iobfd; iobfd = ibfd; - if (ibfd->my_archive && !bfd_is_thin_archive (ibfd->my_archive)) - iobfd = ibfd->my_archive; + while (iobfd->my_archive + && !bfd_is_thin_archive (iobfd->my_archive)) + iobfd = iobfd->my_archive; file->name = iobfd->filename; if (!iobfd->iostream && !bfd_open_file (iobfd)) return 0; - file->fd = fileno ((FILE *) iobfd->iostream); + /* The plugin API expects that the file descriptor won't be closed + and reused as done by the bfd file cache. So open it again. + dup isn't good enough. plugin IO uses lseek/read while BFD uses + fseek/fread. It isn't wise to mix the unistd and stdio calls on + the same underlying file descriptor. */ + file->fd = open (file->name, O_RDONLY | O_BINARY); + if (file->fd < 0) + return 0; if (iobfd == ibfd) { @@ -197,12 +205,12 @@ try_claim (bfd *abfd) int claimed = 0; struct ld_plugin_input_file file; + file.handle = abfd; if (!bfd_plugin_open_input (abfd, &file)) return 0; - file.handle = abfd; - off_t cur_offset = lseek (file.fd, 0, SEEK_CUR); claim_file (&file, &claimed); - lseek (file.fd, cur_offset, SEEK_SET); + if (!claimed) + close (file.fd); return claimed; } diff --git a/bfd/sysdep.h b/bfd/sysdep.h index 840c028..bc7dbcf 100644 --- a/bfd/sysdep.h +++ b/bfd/sysdep.h @@ -108,6 +108,10 @@ extern char *strrchr (); #ifndef O_ACCMODE #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR) #endif +/* Systems that don't already define this, don't need it. */ +#ifndef O_BINARY +#define O_BINARY 0 +#endif #ifndef SEEK_SET #define SEEK_SET 0 |