From FEDORA_PATCHES Mon Sep 17 00:00:00 2001

From: Keith Seitz <keiths@redhat.com>

Date: Mon, 27 Jul 2020 16:34:37 -0400

Subject: gdb-rhbz1842691-corefile-mem-access-1of15.patch

;; Remove hack for GDB which sets the section size to 0

;; Kevin Buettner, RH BZ 1842691

    Author: Kevin Buettner <kevinb@redhat.com>

    Remove hack for GDB which sets the section size to 0

    This commit removes a hack for GDB which was introduced in 2007.

    See:

        https://sourceware.org/ml/binutils/2007-08/msg00044.html

    That hack mostly allowed GDB's handling of core files to continue to

    work without any changes to GDB.

    The problem with setting the section size to zero is that GDB won't

    know how big that section is/was.  Often, this doesn't matter because

    the data in question are found in the exec file.  But it can happen

    that the section describes memory that had been allocated, but never

    written to.  In this instance, the contents of that memory region are

    not written to the core file.  Also, since the region in question was

    dynamically allocated, it won't appear in the exec file.  We don't

    want these regions to appear as inaccessible to GDB (since they *were*

    accessible when the process was live), so it's important that GDB know

    the size of the region.

    I've made changes to GDB which correctly handles this case.  When

    attempting to access memory, GDB will first consider core file data

    for which both SEC_ALLOC and SEC_HAS_CONTENTS is set.  Next, if that

    fails, GDB will attempt to find the data in the exec file.  Finally,

    if that also fails, GDB will attempt to access memory in the sections

    which are flagged as SEC_ALLOC, but not SEC_HAS_CONTENTS.

    bfd/ChangeLog:

        * elf.c (_bfd_elf_make_section_from_phdr): Remove hack for GDB.

diff --git a/bfd/elf.c b/bfd/elf.c

--- a/bfd/elf.c

+++ b/bfd/elf.c

@@ -2975,14 +2975,6 @@ _bfd_elf_make_section_from_phdr (bfd *abfd,

       newsect->alignment_power = bfd_log2 (align);

       if (hdr->p_type == PT_LOAD)

 	{

-	  /* Hack for gdb.  Segments that have not been modified do

-	     not have their contents written to a core file, on the

-	     assumption that a debugger can find the contents in the

-	     executable.  We flag this case by setting the fake

-	     section size to zero.  Note that "real" bss sections will

-	     always have their contents dumped to the core file.  */

-	  if (bfd_get_format (abfd) == bfd_core)

-	    newsect->size = 0;

 	  newsect->flags |= SEC_ALLOC;

 	  if (hdr->p_flags & PF_X)

 	    newsect->flags |= SEC_CODE;