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Re: PATCH: PR ld/13909: PR ld/12570 causes eh_frame_hdr section to be sometimes too large
On Wed, May 23, 2012 at 4:59 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> 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]$
>
This works for me.
--
H.J.
---
diff --git a/bfd/elf-eh-frame.c b/bfd/elf-eh-frame.c
index 685540c..32714bb 100644
--- a/bfd/elf-eh-frame.c
+++ b/bfd/elf-eh-frame.c
@@ -1280,6 +1280,7 @@ _bfd_elf_maybe_strip_eh_frame_hdr (struct
bfd_link_info *info)
o = bfd_get_section_by_name (abfd, ".eh_frame");
while (o != NULL
&& (o->size <= 8
+ || (o->flags & SEC_LINKER_CREATED) != 0
|| bfd_is_abs_section (o->output_section)))
o = bfd_get_next_section_by_name (o);
if (o != NULL)