toolchain/binutils/patches/2.30/100-PR23254-ld.bfd-mishandles-file-pointers-while-scanni.patch

   1 From: Alan Modra <amodra@gmail.com>
   2 Date: Tue, 5 Jun 2018 21:04:00 +0930
   3 Subject: [PATCH] PR23254, ld.bfd mishandles file pointers while scanning
   4  archive
   5
   6 Best practice is to not mix lseek/read with fseek/fread on the same
   7 underlying file descriptor, as not all stdio implementations will cope.
   8 Since the plugin uses lseek/read while bfd uses fseek/fread this patch
   9 reopens the file for exclusive use by the plugin rather than trying to
  10 restore the file descriptor.  That allows the plugin to read the file
  11 after plugin_call_claim_file too.
  12
  13 bfd/
  14         PR 23254
  15         * plugin.c (bfd_plugin_open_input): Allow for possibility of
  16         nested archives.  Open file again for plugin.
  17         (try_claim): Don't save and restore file position.  Close file
  18         if not claimed.
  19         * sysdep.h (O_BINARY): Define.
  20 ld/
  21         PR 23254
  22         * plugin.c (plugin_call_claim_file): Revert 2016-07-19 patch.
  23         (plugin_object_p): Don't dup file descriptor.
  24 ---
  25
  26 --- a/bfd/plugin.c
  27 +++ b/bfd/plugin.c
  28 @@ -165,14 +165,22 @@ bfd_plugin_open_input (bfd *ibfd, struct
  29    bfd *iobfd;
  30
  31    iobfd = ibfd;
  32 -  if (ibfd->my_archive && !bfd_is_thin_archive (ibfd->my_archive))
  33 -    iobfd = ibfd->my_archive;
  34 +  while (iobfd->my_archive
  35 +        && !bfd_is_thin_archive (iobfd->my_archive))
  36 +    iobfd = iobfd->my_archive;
  37    file->name = iobfd->filename;
  38
  39    if (!iobfd->iostream && !bfd_open_file (iobfd))
  40      return 0;
  41
  42 -  file->fd = fileno ((FILE *) iobfd->iostream);
  43 +  /* The plugin API expects that the file descriptor won't be closed
  44 +     and reused as done by the bfd file cache.  So open it again.
  45 +     dup isn't good enough.  plugin IO uses lseek/read while BFD uses
  46 +     fseek/fread.  It isn't wise to mix the unistd and stdio calls on
  47 +     the same underlying file descriptor.  */
  48 +  file->fd = open (file->name, O_RDONLY | O_BINARY);
  49 +  if (file->fd < 0)
  50 +    return 0;
  51
  52    if (iobfd == ibfd)
  53      {
  54 @@ -196,12 +204,12 @@ try_claim (bfd *abfd)
  55    int claimed = 0;
  56    struct ld_plugin_input_file file;
  57
  58 +  file.handle = abfd;
  59    if (!bfd_plugin_open_input (abfd, &file))
  60      return 0;
  61 -  file.handle = abfd;
  62 -  off_t cur_offset = lseek (file.fd, 0, SEEK_CUR);
  63    claim_file (&file, &claimed);
  64 -  lseek (file.fd, cur_offset, SEEK_SET);
  65 +  if (!claimed)
  66 +    close (file.fd);
  67    return claimed;
  68  }
  69
  70 --- a/bfd/sysdep.h
  71 +++ b/bfd/sysdep.h
  72 @@ -108,6 +108,10 @@ extern char *strrchr ();
  73  #ifndef O_ACCMODE
  74  #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
  75  #endif
  76 +/* Systems that don't already define this, don't need it.  */
  77 +#ifndef O_BINARY
  78 +#define O_BINARY 0
  79 +#endif
  80
  81  #ifndef SEEK_SET
  82  #define SEEK_SET 0
  83 --- a/ld/plugin.c
  84 +++ b/ld/plugin.c
  85 @@ -1053,14 +1053,10 @@ plugin_call_claim_file (const struct ld_
  86      {
  87        if (curplug->claim_file_handler)
  88         {
  89 -         off_t cur_offset;
  90           enum ld_plugin_status rv;
  91
  92           called_plugin = curplug;
  93 -         cur_offset = lseek (file->fd, 0, SEEK_CUR);
  94           rv = (*curplug->claim_file_handler) (file, claimed);
  95 -         if (!*claimed)
  96 -           lseek (file->fd, cur_offset, SEEK_SET);
  97           called_plugin = NULL;
  98           if (rv != LDPS_OK)
  99             set_plugin_error (curplug->name);
 100 @@ -1126,12 +1122,6 @@ plugin_object_p (bfd *ibfd)
 101      }
 102
 103    file.handle = input;
 104 -  /* The plugin API expects that the file descriptor won't be closed
 105 -     and reused as done by the bfd file cache.  So dup one.  */
 106 -  file.fd = dup (file.fd);
 107 -  if (file.fd < 0)
 108 -    return NULL;
 109 -
 110    input->abfd = abfd;
 111    input->view_buffer.addr = NULL;
 112    input->view_buffer.filesize = 0;