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ppc64 ld toc edit hang
- From: Alan Modra <amodra at gmail dot com>
- To: binutils at sourceware dot org
- Date: Mon, 5 Nov 2012 15:54:21 +1030
- Subject: ppc64 ld toc edit hang
An assembly testcase I generated last week made ppc64 ld hang, the
cause a "repeat" variable once set never being cleared. A toc entry
referring to another toc entry as I had in my testcase is fortunately
never generated by gcc, and apparently no one has found the need for
such a thing even in user assembly. Committed.
* elf64-ppc.c (ppc64_elf_edit_toc): Clear "repeat" inside
loop. Really mark toc entry referring to another toc entry
only if the first is used.
Index: bfd/elf64-ppc.c
===================================================================
RCS file: /cvs/src/src/bfd/elf64-ppc.c,v
retrieving revision 1.393
diff -u -p -r1.393 elf64-ppc.c
--- bfd/elf64-ppc.c 12 Sep 2012 22:56:05 -0000 1.393
+++ bfd/elf64-ppc.c 5 Nov 2012 00:39:13 -0000
@@ -8372,150 +8375,156 @@ ppc64_elf_edit_toc (struct bfd_link_info
goto error_ret;
/* Mark toc entries referenced as used. */
- repeat = 0;
do
- for (rel = relstart; rel < relstart + sec->reloc_count; ++rel)
- {
- enum elf_ppc64_reloc_type r_type;
- unsigned long r_symndx;
- asection *sym_sec;
- struct elf_link_hash_entry *h;
- Elf_Internal_Sym *sym;
- bfd_vma val;
- enum {no_check, check_lo, check_ha} insn_check;
-
- r_type = ELF64_R_TYPE (rel->r_info);
- switch (r_type)
- {
- default:
- insn_check = no_check;
- break;
+ {
+ repeat = 0;
+ for (rel = relstart; rel < relstart + sec->reloc_count; ++rel)
+ {
+ enum elf_ppc64_reloc_type r_type;
+ unsigned long r_symndx;
+ asection *sym_sec;
+ struct elf_link_hash_entry *h;
+ Elf_Internal_Sym *sym;
+ bfd_vma val;
+ enum {no_check, check_lo, check_ha} insn_check;
- case R_PPC64_GOT_TLSLD16_HA:
- case R_PPC64_GOT_TLSGD16_HA:
- case R_PPC64_GOT_TPREL16_HA:
- case R_PPC64_GOT_DTPREL16_HA:
- case R_PPC64_GOT16_HA:
- case R_PPC64_TOC16_HA:
- insn_check = check_ha;
- break;
+ r_type = ELF64_R_TYPE (rel->r_info);
+ switch (r_type)
+ {
+ default:
+ insn_check = no_check;
+ break;
- case R_PPC64_GOT_TLSLD16_LO:
- case R_PPC64_GOT_TLSGD16_LO:
- case R_PPC64_GOT_TPREL16_LO_DS:
- case R_PPC64_GOT_DTPREL16_LO_DS:
- case R_PPC64_GOT16_LO:
- case R_PPC64_GOT16_LO_DS:
- case R_PPC64_TOC16_LO:
- case R_PPC64_TOC16_LO_DS:
- insn_check = check_lo;
- break;
- }
+ case R_PPC64_GOT_TLSLD16_HA:
+ case R_PPC64_GOT_TLSGD16_HA:
+ case R_PPC64_GOT_TPREL16_HA:
+ case R_PPC64_GOT_DTPREL16_HA:
+ case R_PPC64_GOT16_HA:
+ case R_PPC64_TOC16_HA:
+ insn_check = check_ha;
+ break;
- if (insn_check != no_check)
- {
- bfd_vma off = rel->r_offset & ~3;
- unsigned char buf[4];
- unsigned int insn;
+ case R_PPC64_GOT_TLSLD16_LO:
+ case R_PPC64_GOT_TLSGD16_LO:
+ case R_PPC64_GOT_TPREL16_LO_DS:
+ case R_PPC64_GOT_DTPREL16_LO_DS:
+ case R_PPC64_GOT16_LO:
+ case R_PPC64_GOT16_LO_DS:
+ case R_PPC64_TOC16_LO:
+ case R_PPC64_TOC16_LO_DS:
+ insn_check = check_lo;
+ break;
+ }
- if (!bfd_get_section_contents (ibfd, sec, buf, off, 4))
- {
- free (used);
- goto error_ret;
- }
- insn = bfd_get_32 (ibfd, buf);
- if (insn_check == check_lo
- ? !ok_lo_toc_insn (insn)
- : ((insn & ((0x3f << 26) | 0x1f << 16))
- != ((15u << 26) | (2 << 16)) /* addis rt,2,imm */))
- {
- char str[12];
+ if (insn_check != no_check)
+ {
+ bfd_vma off = rel->r_offset & ~3;
+ unsigned char buf[4];
+ unsigned int insn;
- ppc64_elf_tdata (ibfd)->unexpected_toc_insn = 1;
- sprintf (str, "%#08x", insn);
- info->callbacks->einfo
- (_("%P: %H: toc optimization is not supported for"
- " %s instruction.\n"),
- ibfd, sec, rel->r_offset & ~3, str);
- }
- }
+ if (!bfd_get_section_contents (ibfd, sec, buf, off, 4))
+ {
+ free (used);
+ goto error_ret;
+ }
+ insn = bfd_get_32 (ibfd, buf);
+ if (insn_check == check_lo
+ ? !ok_lo_toc_insn (insn)
+ : ((insn & ((0x3f << 26) | 0x1f << 16))
+ != ((15u << 26) | (2 << 16)) /* addis rt,2,imm */))
+ {
+ char str[12];
- switch (r_type)
- {
- case R_PPC64_TOC16:
- case R_PPC64_TOC16_LO:
- case R_PPC64_TOC16_HI:
- case R_PPC64_TOC16_HA:
- case R_PPC64_TOC16_DS:
- case R_PPC64_TOC16_LO_DS:
- /* In case we're taking addresses of toc entries. */
- case R_PPC64_ADDR64:
- break;
+ ppc64_elf_tdata (ibfd)->unexpected_toc_insn = 1;
+ sprintf (str, "%#08x", insn);
+ info->callbacks->einfo
+ (_("%P: %H: toc optimization is not supported for"
+ " %s instruction.\n"),
+ ibfd, sec, rel->r_offset & ~3, str);
+ }
+ }
- default:
- continue;
- }
+ switch (r_type)
+ {
+ case R_PPC64_TOC16:
+ case R_PPC64_TOC16_LO:
+ case R_PPC64_TOC16_HI:
+ case R_PPC64_TOC16_HA:
+ case R_PPC64_TOC16_DS:
+ case R_PPC64_TOC16_LO_DS:
+ /* In case we're taking addresses of toc entries. */
+ case R_PPC64_ADDR64:
+ break;
- r_symndx = ELF64_R_SYM (rel->r_info);
- if (!get_sym_h (&h, &sym, &sym_sec, NULL, &local_syms,
- r_symndx, ibfd))
- {
- free (used);
- goto error_ret;
- }
+ default:
+ continue;
+ }
- if (sym_sec != toc)
- continue;
+ r_symndx = ELF64_R_SYM (rel->r_info);
+ if (!get_sym_h (&h, &sym, &sym_sec, NULL, &local_syms,
+ r_symndx, ibfd))
+ {
+ free (used);
+ goto error_ret;
+ }
- if (h != NULL)
- val = h->root.u.def.value;
- else
- val = sym->st_value;
- val += rel->r_addend;
+ if (sym_sec != toc)
+ continue;
- if (val >= toc->size)
- continue;
+ if (h != NULL)
+ val = h->root.u.def.value;
+ else
+ val = sym->st_value;
+ val += rel->r_addend;
- if ((skip[val >> 3] & can_optimize) != 0)
- {
- bfd_vma off;
- unsigned char opc;
+ if (val >= toc->size)
+ continue;
- switch (r_type)
- {
- case R_PPC64_TOC16_HA:
- break;
+ if ((skip[val >> 3] & can_optimize) != 0)
+ {
+ bfd_vma off;
+ unsigned char opc;
- case R_PPC64_TOC16_LO_DS:
- off = rel->r_offset + (bfd_big_endian (ibfd) ? -2 : 3);
- if (!bfd_get_section_contents (ibfd, sec, &opc, off, 1))
- {
- free (used);
- goto error_ret;
- }
- if ((opc & (0x3f << 2)) == (58u << 2))
+ switch (r_type)
+ {
+ case R_PPC64_TOC16_HA:
break;
- /* Fall thru */
- default:
- /* Wrong sort of reloc, or not a ld. We may
- as well clear ref_from_discarded too. */
- skip[val >> 3] = 0;
- }
- }
+ case R_PPC64_TOC16_LO_DS:
+ off = rel->r_offset;
+ off += (bfd_big_endian (ibfd) ? -2 : 3);
+ if (!bfd_get_section_contents (ibfd, sec, &opc,
+ off, 1))
+ {
+ free (used);
+ goto error_ret;
+ }
+ if ((opc & (0x3f << 2)) == (58u << 2))
+ break;
+ /* Fall thru */
- /* For the toc section, we only mark as used if
- this entry itself isn't unused. */
- if (sec == toc
- && !used[val >> 3]
- && (used[rel->r_offset >> 3]
- || !(skip[rel->r_offset >> 3] & ref_from_discarded)))
- /* Do all the relocs again, to catch reference
- chains. */
- repeat = 1;
+ default:
+ /* Wrong sort of reloc, or not a ld. We may
+ as well clear ref_from_discarded too. */
+ skip[val >> 3] = 0;
+ }
+ }
- used[val >> 3] = 1;
- }
+ if (sec != toc)
+ used[val >> 3] = 1;
+ /* For the toc section, we only mark as used if this
+ entry itself isn't unused. */
+ else if ((used[rel->r_offset >> 3]
+ || !(skip[rel->r_offset >> 3] & ref_from_discarded))
+ && !used[val >> 3])
+ {
+ /* Do all the relocs again, to catch reference
+ chains. */
+ repeat = 1;
+ used[val >> 3] = 1;
+ }
+ }
+ }
while (repeat);
if (elf_section_data (sec)->relocs != relstart)
--
Alan Modra
Australia Development Lab, IBM