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authorAlan Modra <amodra@gmail.com>2019-03-18 21:38:36 +1030
committerAlan Modra <amodra@gmail.com>2019-03-18 22:38:29 +1030
commit8cd1fe1bf525b59f4d07e5790d11d49eee7e8494 (patch)
treeb54654c1967d9cc2a3693e727a77f5e7114987ad /bfd
parent28a66f07f0695c740dc0e1b043cd36f90dbfb5ea (diff)
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PR24355, segmentation fault in function called from ppc_finish_symbols
This one looks to be a bug going back to 2009, git commit e054468f6c "STT_GNU_IFUNC support for PowerPC". That bug was carried over with git commit 49c09209d0 "Rearrange PLT reloc output on powerpc". If the refcount for an ifunc local sym plt entry was zero, ppc_elf_size_dynamic_sections would correctly set plt.offset to -1 but leave glink_offset uninitialized. That leads to occasional segfaults (which can be made solid with MALLOC_PERTURB_=1 when using glibc). So, guard the write_glink_stub call with plt.offset != -1. Also, remove the totally ineffective attempt at writing multiple-use glink stubs only once. PR 24355 * elf32-ppc.c (ppc_finish_symbols): Don't call write_glink_stub for local iplt syms with ent->plt.offset == -1. Remove ineffective attempt at writing glink stubs only once.
Diffstat (limited to 'bfd')
-rw-r--r--bfd/ChangeLog7
-rw-r--r--bfd/elf32-ppc.c8
2 files changed, 9 insertions, 6 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index f92b273..9cdd4fe 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,10 @@
+2019-03-18 Alan Modra <amodra@gmail.com>
+
+ PR 24355
+ * elf32-ppc.c (ppc_finish_symbols): Don't call write_glink_stub
+ for local iplt syms with ent->plt.offset == -1. Remove ineffective
+ attempt at writing glink stubs only once.
+
2019-03-16 Alan Modra <amodra@gmail.com>
PR 24337
diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c
index 593ef47..6991e8d 100644
--- a/bfd/elf32-ppc.c
+++ b/bfd/elf32-ppc.c
@@ -9704,6 +9704,7 @@ ppc_finish_symbols (struct bfd_link_info *info)
bfd_byte *loc;
bfd_vma val;
Elf_Internal_Rela rela;
+ unsigned char *p;
if (!get_sym_h (NULL, &sym, &sym_sec, NULL, &local_syms,
lplt - local_plt, ibfd))
@@ -9748,14 +9749,9 @@ ppc_finish_symbols (struct bfd_link_info *info)
loc = relplt->contents + (relplt->reloc_count++
* sizeof (Elf32_External_Rela));
bfd_elf32_swap_reloca_out (info->output_bfd, &rela, loc);
- }
- if ((ent->glink_offset & 1) == 0)
- {
- unsigned char *p = ((unsigned char *) htab->glink->contents
- + ent->glink_offset);
+ p = (unsigned char *) htab->glink->contents + ent->glink_offset;
write_glink_stub (NULL, ent, htab->elf.iplt, p, info);
- ent->glink_offset |= 1;
}
}