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Re: PowerPC64 plt call stubs
- From: Alan Modra <amodra at gmail dot com>
- To: binutils at sourceware dot org
- Date: Tue, 2 Aug 2011 14:15:07 +0930
- Subject: Re: PowerPC64 plt call stubs
- References: <20110714032835.GT26365@bubble.grove.modra.org>
On Thu, Jul 14, 2011 at 12:58:35PM +0930, Alan Modra wrote:
> This makes plt call stubs omit the load of r11. As far as I know,
> there isn't any reason to ever load r11 when making a call via the
> PLT, so the default is to omit. Committed.
I forgot that relocs are emitted for the plt stubs.
* elf64-ppc.c (build_plt_stub): Correct emitted relocs when no
plt_static_chain.
(ppc_build_one_stub): Adjust get_relocs call to suit..
(ppc_size_one_stub): ..and reloc sizing. Correct plt size corner case.
Index: bfd/elf64-ppc.c
===================================================================
RCS file: /cvs/src/src/bfd/elf64-ppc.c,v
retrieving revision 1.357
diff -u -p -r1.357 elf64-ppc.c
--- bfd/elf64-ppc.c 26 Jul 2011 01:57:16 -0000 1.357
+++ bfd/elf64-ppc.c 2 Aug 2011 02:50:56 -0000
@@ -9291,7 +9291,7 @@ build_plt_stub (bfd *obfd, bfd_byte *p,
r[1].r_offset = r[0].r_offset + 8;
r[1].r_info = ELF64_R_INFO (0, R_PPC64_TOC16_LO_DS);
r[1].r_addend = r[0].r_addend;
- if (PPC_HA (offset + 16) != PPC_HA (offset))
+ if (PPC_HA (offset + 8 + 8 * plt_static_chain) != PPC_HA (offset))
{
r[2].r_offset = r[1].r_offset + 4;
r[2].r_info = ELF64_R_INFO (0, R_PPC64_TOC16_LO);
@@ -9302,9 +9302,12 @@ build_plt_stub (bfd *obfd, bfd_byte *p,
r[2].r_offset = r[1].r_offset + 8;
r[2].r_info = ELF64_R_INFO (0, R_PPC64_TOC16_LO_DS);
r[2].r_addend = r[0].r_addend + 8;
- r[3].r_offset = r[2].r_offset + 4;
- r[3].r_info = ELF64_R_INFO (0, R_PPC64_TOC16_LO_DS);
- r[3].r_addend = r[0].r_addend + 16;
+ if (plt_static_chain)
+ {
+ r[3].r_offset = r[2].r_offset + 4;
+ r[3].r_info = ELF64_R_INFO (0, R_PPC64_TOC16_LO_DS);
+ r[3].r_addend = r[0].r_addend + 16;
+ }
}
}
bfd_put_32 (obfd, ADDIS_R12_R2 | PPC_HA (offset), p), p += 4;
@@ -9327,7 +9330,7 @@ build_plt_stub (bfd *obfd, bfd_byte *p,
{
r[0].r_offset += 4;
r[0].r_info = ELF64_R_INFO (0, R_PPC64_TOC16_DS);
- if (PPC_HA (offset + 16) != PPC_HA (offset))
+ if (PPC_HA (offset + 8 + 8 * plt_static_chain) != PPC_HA (offset))
{
r[1].r_offset = r[0].r_offset + 4;
r[1].r_info = ELF64_R_INFO (0, R_PPC64_TOC16);
@@ -9337,10 +9340,13 @@ build_plt_stub (bfd *obfd, bfd_byte *p,
{
r[1].r_offset = r[0].r_offset + 8;
r[1].r_info = ELF64_R_INFO (0, R_PPC64_TOC16_DS);
- r[1].r_addend = r[0].r_addend + 16;
- r[2].r_offset = r[1].r_offset + 4;
- r[2].r_info = ELF64_R_INFO (0, R_PPC64_TOC16_DS);
- r[2].r_addend = r[0].r_addend + 8;
+ r[1].r_addend = r[0].r_addend + 8 + 8 * plt_static_chain;
+ if (plt_static_chain)
+ {
+ r[2].r_offset = r[1].r_offset + 4;
+ r[2].r_info = ELF64_R_INFO (0, R_PPC64_TOC16_DS);
+ r[2].r_addend = r[0].r_addend + 8;
+ }
}
}
bfd_put_32 (obfd, STD_R2_40R1, p), p += 4;
@@ -9808,8 +9814,10 @@ ppc_build_one_stub (struct bfd_hash_entr
if (info->emitrelocations)
{
r = get_relocs (stub_entry->stub_sec,
- (2 + (PPC_HA (off) != 0)
- + (PPC_HA (off + 16) == PPC_HA (off))));
+ (2
+ + (PPC_HA (off) != 0)
+ + (htab->plt_static_chain
+ && PPC_HA (off + 16) == PPC_HA (off))));
if (r == NULL)
return FALSE;
r[0].r_offset = loc - stub_entry->stub_sec->contents;
@@ -9916,7 +9924,7 @@ ppc_size_one_stub (struct bfd_hash_entry
size -= 4;
if (PPC_HA (off) == 0)
size -= 4;
- if (PPC_HA (off + 16) != PPC_HA (off))
+ if (PPC_HA (off + 8 + 8 * htab->plt_static_chain) != PPC_HA (off))
size += 4;
if (stub_entry->h != NULL
&& (stub_entry->h == htab->tls_get_addr_fd
@@ -9926,7 +9934,10 @@ ppc_size_one_stub (struct bfd_hash_entry
if (info->emitrelocations)
{
stub_entry->stub_sec->reloc_count
- += 2 + (PPC_HA (off) != 0) + (PPC_HA (off + 16) == PPC_HA (off));
+ += (2
+ + (PPC_HA (off) != 0)
+ + (htab->plt_static_chain
+ && PPC_HA (off + 16) == PPC_HA (off)));
stub_entry->stub_sec->flags |= SEC_RELOC;
}
}
--
Alan Modra
Australia Development Lab, IBM