Re: [PATCH v4 3/7] bfd: Improve nm and objdump without section header

[Simon Marchi via Gdb-patches <gdb-patches@sourceware.org>]

> It works for me:
> 
> $ make check TESTS="gdb.base/eu-strip-infcall.exp"
> ....
> === gdb Summary ===
> 
> # of expected passes 1
> 
> My change only impacts files without section header. eu-strip-infcall.exp does
> "eu-strip -f ${binfile}.debug $binfile", which doesn't remove section header.
> 

I can reliably reproduce the problem on two separate machine, one Ubuntu
22.04 and one failrly up to date Arch Linux.  elfutils version 0.186 and
0.189, respectively.

It goes wrong when GDB does a bfd_check_format call on
testsuite/outputs/gdb.base/eu-strip-infcall/eu-strip-infcall.debug.
Before you commit it works, and after your commit it returns false.  It
happens in this new statement added to elf_object_p, added by the commit:

	      if ((i_phdr->p_offset + i_phdr->p_filesz) > filesize)
		goto got_no_match;

(top-gdb) p i_phdr->p_offset
$1 = 8192
(top-gdb) p i_phdr->p_filesz
$2 = 196
(top-gdb) p filesize
$3 = 5104
(top-gdb) p i
$4 = 4

It would be this program header causing the condition to fail:

  Type           Offset   VirtAddr           PhysAddr           FileSiz  MemSiz   Flg Align
  ...
  LOAD           0x002000 0x0000000000002000 0x0000000000002000 0x0000c4 0x0000c4 R   0x1000

So, the program header of the .debug file describes the segments of the
main binary, not sure if that's expected.

Simon