[v4,06/14] Update binary_get_section_contents to seek using section's file position

Message ID 20200705225807.2264705-7-kevinb@redhat.com
State Superseded
Headers show
Series
  • Fix BZ 25631 - core file memory access problem
Related show

Commit Message

Pedro Franco de Carvalho via Gdb-patches July 5, 2020, 10:57 p.m.
I have a patch for GDB which opens and reads from BFDs using the
"binary" target.  However, for it to work, we need to be able to get a
section's contents based from the file position of that section.

At the moment, reading a section's contents will always read from the
start of the file regardless of where that section is located.  While
this was fine for the original use of the "binary" target, it won't
work for my use case.  This change shouldn't impact any existing
callers due to the fact that the single .data section is initialized
with a filepos of 0.

bfd/ChangeLog:

	* binary.c (binary_get_section_contents): Seek using offset
	from section's file position.
---
 bfd/binary.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

-- 
2.26.2

Patch

diff --git a/bfd/binary.c b/bfd/binary.c
index 999de0d8c4..e872924a2d 100644
--- a/bfd/binary.c
+++ b/bfd/binary.c
@@ -19,10 +19,10 @@ 
    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
    MA 02110-1301, USA.  */
 
-/* This is a BFD backend which may be used to write binary objects.
-   It may only be used for output, not input.  The intention is that
-   this may be used as an output format for objcopy in order to
-   generate raw binary data.
+/* This is a BFD backend which may be used to read or write binary
+   objects.  Historically, it was used as an output format for objcopy
+   in order to generate raw binary data, but is now used for other
+   purposes as well.
 
    This is very simple.  The only complication is that the real data
    will start at some address X, and in some cases we will not want to
@@ -97,12 +97,12 @@  binary_object_p (bfd *abfd)
 
 static bfd_boolean
 binary_get_section_contents (bfd *abfd,
-			     asection *section ATTRIBUTE_UNUSED,
+			     asection *section,
 			     void * location,
 			     file_ptr offset,
 			     bfd_size_type count)
 {
-  if (bfd_seek (abfd, offset, SEEK_SET) != 0
+  if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0
       || bfd_bread (location, count, abfd) != count)
     return FALSE;
   return TRUE;