dwarf2 and objdump -S --adjust-vma

[Karsten Keil <kkeil at suse dot de>]

Hi,

while debuging some x86-64 kernel problem I found a bug in
dwarf and objdump -S --adjust-vma handling.
It's not x86-64 related, following simple testcase shows the bug even on
i386:

Famous c code :-) hello.c:
main() {
printf("hello world\n");
}

cc -gdwarf-2 -c -o hello.o hello.c

objdump -S --adjust-vma 0x0 hello.o works as expected:

hello.o:     file format elf32-i386

Disassembly of section .text:

00000000 <main>:
   0:   55                      push   %ebp
   1:   89 e5                   mov    %esp,%ebp
   3:   83 ec 08                sub    $0x8,%esp
main() {
printf("hello world\n");
   6:   83 c4 f4                add    $0xfffffff4,%esp
   9:   68 00 00 00 00          push   $0x0
   e:   e8 fc ff ff ff          call   f <main+0xf>
  13:   83 c4 10                add    $0x10,%esp
}
  16:   89 ec                   mov    %ebp,%esp
  18:   5d                      pop    %ebp
  19:   c3                      ret
  1a:   8d b6 00 00 00 00       lea    0x0(%esi),%esi

But
objdump -S --adjust-vma 0x10 hello.o
shows the bug:

hello.o:     file format elf32-i386

Disassembly of section .text:

00000010 <main>:
main() {
printf("hello world\n");
  10:   55                      push   %ebp
  11:   89 e5                   mov    %esp,%ebp
  13:   83 ec 08                sub    $0x8,%esp
}
  16:   83 c4 f4                add    $0xfffffff4,%esp
  19:   68 00 00 00 00          push   $0x0
  1e:   e8 fc ff ff ff          call   1f <main+0xf>
  23:   83 c4 10                add    $0x10,%esp
  26:   89 ec                   mov    %ebp,%esp
  28:   5d                      pop    %ebp
  29:   c3                      ret
  2a:   8d b6 00 00 00 00       lea    0x0(%esi),%esi


The source code inserts are shifted with --adjust-vma offset and are gone
away if offset are big.

Tested with binutils CVS two days ago.

-- 
Karsten Keil
SuSE Labs
ISDN development