* PowerPC64 synthetic syms
@ 2006-05-23 6:07 Alan Modra
2006-05-23 15:48 ` Andreas Schwab
0 siblings, 1 reply; 4+ messages in thread
From: Alan Modra @ 2006-05-23 6:07 UTC (permalink / raw)
To: binutils
PowerPC64 bfd_get_synthetic_symtab provides pseudo function entry
symbols (dot-symbols) for object files generated by newer toolchains.
This is useful for objdump disassembly of object files. gdb also has
at least one place where a dot-symbol is searched, solib-svr4.c
solib_break_names, so relies on bfd_get_synthetic_symtab. A recent
testcase shows this to be unreliable because the ppc64 back-end only
creates one synthetic sym for each function descriptor, and ld.so
happens to have *two* symbols pointing at the functions descriptor.
Which dot-symbol is created depends on symbol table hash order.
Really, gdb should be looking up the function descriptor syms itself
instead of relying on a crutch like the synthetic syms, but the
following patch happens to cure gdb and makes sense in isolation.
Applying mainline and 2.17.
* elf64-ppc.c (compare_symbols): Prefer strong dynamic global
function syms over other syms.
Index: bfd/elf64-ppc.c
===================================================================
RCS file: /cvs/src/src/bfd/elf64-ppc.c,v
retrieving revision 1.238
diff -u -p -r1.238 elf64-ppc.c
--- bfd/elf64-ppc.c 9 May 2006 03:38:30 -0000 1.238
+++ bfd/elf64-ppc.c 23 May 2006 01:29:40 -0000
@@ -2626,6 +2626,32 @@ compare_symbols (const void *ap, const v
if (a->value + a->section->vma > b->value + b->section->vma)
return 1;
+ /* For syms with the same value, prefer strong dynamic global function
+ syms over other syms. */
+ if ((a->flags & BSF_GLOBAL) != 0 && (b->flags & BSF_GLOBAL) == 0)
+ return -1;
+
+ if ((a->flags & BSF_GLOBAL) == 0 && (b->flags & BSF_GLOBAL) != 0)
+ return 1;
+
+ if ((a->flags & BSF_FUNCTION) != 0 && (b->flags & BSF_FUNCTION) == 0)
+ return -1;
+
+ if ((a->flags & BSF_FUNCTION) == 0 && (b->flags & BSF_FUNCTION) != 0)
+ return 1;
+
+ if ((a->flags & BSF_WEAK) == 0 && (b->flags & BSF_WEAK) != 0)
+ return -1;
+
+ if ((a->flags & BSF_WEAK) != 0 && (b->flags & BSF_WEAK) == 0)
+ return 1;
+
+ if ((a->flags & BSF_DYNAMIC) != 0 && (b->flags & BSF_DYNAMIC) == 0)
+ return -1;
+
+ if ((a->flags & BSF_DYNAMIC) == 0 && (b->flags & BSF_DYNAMIC) != 0)
+ return 1;
+
return 0;
}
--
Alan Modra
IBM OzLabs - Linux Technology Centre
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: PowerPC64 synthetic syms
2006-05-23 6:07 PowerPC64 synthetic syms Alan Modra
@ 2006-05-23 15:48 ` Andreas Schwab
2006-05-24 8:13 ` Alan Modra
0 siblings, 1 reply; 4+ messages in thread
From: Andreas Schwab @ 2006-05-23 15:48 UTC (permalink / raw)
To: binutils
Alan Modra <amodra@bigpond.net.au> writes:
> Really, gdb should be looking up the function descriptor syms itself
> instead of relying on a crutch like the synthetic syms, but the
> following patch happens to cure gdb and makes sense in isolation.
> Applying mainline and 2.17.
I think you want to apply that to the gdb-6.5 branch as well.
Andreas.
--
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, MaxfeldstraÃe 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: PowerPC64 synthetic syms
2006-05-23 15:48 ` Andreas Schwab
@ 2006-05-24 8:13 ` Alan Modra
2006-05-24 8:17 ` Daniel Jacobowitz
0 siblings, 1 reply; 4+ messages in thread
From: Alan Modra @ 2006-05-24 8:13 UTC (permalink / raw)
To: Andreas Schwab, gdb-patches; +Cc: binutils
On Tue, May 23, 2006 at 02:09:42PM +0200, Andreas Schwab wrote:
> Alan Modra <amodra@bigpond.net.au> writes:
>
> > Really, gdb should be looking up the function descriptor syms itself
> > instead of relying on a crutch like the synthetic syms, but the
> > following patch happens to cure gdb and makes sense in isolation.
> > Applying mainline and 2.17.
>
> I think you want to apply that to the gdb-6.5 branch as well.
Probably. I'll need an OK from the relevant gdb authority.
http://sources.redhat.com/ml/binutils/2006-05/msg00389.html
--
Alan Modra
IBM OzLabs - Linux Technology Centre
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: PowerPC64 synthetic syms
2006-05-24 8:13 ` Alan Modra
@ 2006-05-24 8:17 ` Daniel Jacobowitz
0 siblings, 0 replies; 4+ messages in thread
From: Daniel Jacobowitz @ 2006-05-24 8:17 UTC (permalink / raw)
To: Andreas Schwab, gdb-patches, binutils
On Wed, May 24, 2006 at 09:06:57AM +0930, Alan Modra wrote:
> On Tue, May 23, 2006 at 02:09:42PM +0200, Andreas Schwab wrote:
> > Alan Modra <amodra@bigpond.net.au> writes:
> >
> > > Really, gdb should be looking up the function descriptor syms itself
> > > instead of relying on a crutch like the synthetic syms, but the
> > > following patch happens to cure gdb and makes sense in isolation.
> > > Applying mainline and 2.17.
> >
> > I think you want to apply that to the gdb-6.5 branch as well.
>
> Probably. I'll need an OK from the relevant gdb authority.
>
> http://sources.redhat.com/ml/binutils/2006-05/msg00389.html
Yes Please.
--
Daniel Jacobowitz
CodeSourcery
^ permalink raw reply [flat|nested] 4+ messages in thread
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2006-05-23 6:07 PowerPC64 synthetic syms Alan Modra
2006-05-23 15:48 ` Andreas Schwab
2006-05-24 8:13 ` Alan Modra
2006-05-24 8:17 ` Daniel Jacobowitz
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