[binutils-gdb] PR23595, simple objcopy of executable failure for msp430-elf

[Alan Modra <amodra at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=2542e49e21e6b7270f72c7be0fc4ff1a986371da

commit 2542e49e21e6b7270f72c7be0fc4ff1a986371da
Author: Jozef Lawrynowicz <jozef.l@mittosystems.com>
Date:   Mon Sep 3 11:04:05 2018 +0930

    PR23595, simple objcopy of executable failure for msp430-elf
    
    VMA of the first section in the segment containing the ELF file header
    (and possibly section headers too) can't be used to reliably find the
    size of the headers plus padding.  What's really needed is sh_offset
    of the first section assuming it has contents (vma does have a
    relationship to sh_offset, but is only guaranteed in demand paged
    executables).
    
    If the first section is SHT_NOBITS and it hasn't been converted to
    have file contents by the existence of a following SHT_PROGBITS
    section in the same segment, the sh_offset value also isn't reliable.
    
    	PR 23595
    	elf.c (copy_elf_program_header): When first segment contains
    	only the headers and SHT_NOBITS sections, use segment p_filesz
    	to calculate header and padding size.  Use filepos of the first
    	section otherwise.

Diff:
---
 bfd/ChangeLog |  9 +++++++++
 bfd/elf.c     | 16 ++++++++++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 792df8a..9a3b9b1 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,12 @@
+2018-09-03  Jozef Lawrynowicz <jozef.l@mittosystems.com>
+	    Alan Modra  <amodra@gmail.com>
+
+	PR 23595
+	elf.c (copy_elf_program_header): When first segment contains
+	only the headers and SHT_NOBITS sections, use segment p_filesz
+	to calculate header and padding size.  Use filepos of the first
+	section otherwise.
+
 018-08-31  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/23600
diff --git a/bfd/elf.c b/bfd/elf.c
index b8860c4..02d605c 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -7235,6 +7235,7 @@ copy_elf_program_header (bfd *ibfd, bfd *obfd)
       Elf_Internal_Shdr *this_hdr;
       asection *first_section = NULL;
       asection *lowest_section;
+      bfd_boolean no_contents = TRUE;
 
       /* Compute how many sections are in this segment.  */
       for (section = ibfd->sections, section_count = 0;
@@ -7246,6 +7247,8 @@ copy_elf_program_header (bfd *ibfd, bfd *obfd)
 	    {
 	      if (first_section == NULL)
 		first_section = section;
+	      if (elf_section_type (section) != SHT_NOBITS)
+		no_contents = FALSE;
 	      section_count++;
 	    }
 	}
@@ -7342,8 +7345,17 @@ copy_elf_program_header (bfd *ibfd, bfd *obfd)
 	}
 
       if (map->includes_filehdr && lowest_section != NULL)
-	/* We need to keep the space used by the headers fixed.  */
-	map->header_size = lowest_section->vma - segment->p_vaddr;
+	{
+	  /* Try to keep the space used by the headers plus any
+	     padding fixed.  If there are sections with file contents
+	     in this segment then the lowest sh_offset is the best
+	     guess.  Otherwise the segment only has file contents for
+	     the headers, and p_filesz is the best guess.  */
+	  if (no_contents)
+	    map->header_size = segment->p_filesz;
+	  else
+	    map->header_size = lowest_section->filepos;
+	}
 
       if (!map->includes_phdrs
 	  && !map->includes_filehdr