This is the mail archive of the binutils@sourceware.org mailing list for the binutils project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: PATCH: PR ld/13909: PR ld/12570 causes eh_frame_hdr section to be sometimes too large


On Tue, May 22, 2012 at 9:38 PM, Alan Modra <amodra@gmail.com> wrote:
> On Tue, May 22, 2012 at 09:16:22AM -0700, H.J. Lu wrote:
>> ? ? ? * elf-eh-frame.c (_bfd_elf_maybe_strip_eh_frame_hdr): Ignore
>> ? ? ? .eh_frame section created by linker.
>
> We do need this here.
>
> ? ? ? ?* elf-eh-frame.c (_bfd_elf_maybe_strip_eh_frame_hdr): Handle
> ? ? ? ?BFDs with multiple .eh_frame sections.
>
> Index: bfd/elf-eh-frame.c
> ===================================================================
> RCS file: /cvs/src/src/bfd/elf-eh-frame.c,v
> retrieving revision 1.88
> diff -u -p -r1.88 elf-eh-frame.c
> --- bfd/elf-eh-frame.c ?24 Apr 2012 05:12:30 -0000 ? ? ?1.88
> +++ bfd/elf-eh-frame.c ?23 May 2012 04:08:28 -0000
> @@ -1278,7 +1278,11 @@ _bfd_elf_maybe_strip_eh_frame_hdr (struc
> ? ? ? ?/* Count only sections which have at least a single CIE or FDE.
> ? ? ? ? ? There cannot be any CIE or FDE <= 8 bytes. ?*/
> ? ? ? ?o = bfd_get_section_by_name (abfd, ".eh_frame");
> - ? ? ? if (o && o->size > 8 && !bfd_is_abs_section (o->output_section))
> + ? ? ? while (o != NULL
> + ? ? ? ? ? ? ?&& (o->size <= 8
> + ? ? ? ? ? ? ? ? ?|| bfd_is_abs_section (o->output_section)))
> + ? ? ? ? o = bfd_get_next_section_by_name (o);
> + ? ? ? if (o != NULL)
> ? ? ? ? ?break;
> ? ? ? }
>

Shouldn't we ignore linker created .eh_frame section?
Current trunk gave me:

[hjl@gnu-6 pr13909]$ cat dummy.S
[hjl@gnu-6 pr13909]$ ./ld -m elf_i386 -shared --eh-frame-hdr -o z.so
dummy.o -shared -lc
[hjl@gnu-6 pr13909]$ readelf -S z.so
There are 10 section headers, starting at offset 0x1fc:

Section Headers:
  [Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
  [ 0]                   NULL            00000000 000000 000000 00      0   0  0
  [ 1] .hash             HASH            000000b4 0000b4 000024 04   A  2   0  4
  [ 2] .dynsym           DYNSYM          000000d8 0000d8 000040 10   A  3   1  4
  [ 3] .dynstr           STRTAB          00000118 000118 000023 00   A  0   0  1
  [ 4] .eh_frame_hdr     PROGBITS        0000013c 00013c 00000c 00   A  0   0  4
  [ 5] .eh_frame         PROGBITS        00000148 000148 000000 00   A  0   0  4
  [ 6] .dynamic          DYNAMIC         00001148 000148 000060 08  WA  3   0  4
  [ 7] .shstrtab         STRTAB          00000000 0001a8 000052 00      0   0  1
  [ 8] .symtab           SYMTAB          00000000 00038c 0000c0 10      9   9  4
  [ 9] .strtab           STRTAB          00000000 00044c 000038 00      0   0  1
Key to Flags:
  W (write), A (alloc), X (execute), M (merge), S (strings)
  I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown)
  O (extra OS processing required) o (OS specific), p (processor specific)
[hjl@gnu-6 pr13909]$



-- 
H.J.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]