PR22431, powerpc64 ld segfault when .plt discarded

The fix for the PR is to not use input_section->output_section->owner
to get to the output bfd, but use the output bfd directly since it is
available nowadays in struct bfd_link_info.

I thought it worth warning when non-empty dynamic sections are
discarded too, which meant a tweak to one of the ld tests to avoid the
warning.

bfd/
	PR 22431
	* elf64-ppc.c (ppc64_elf_size_dynamic_sections): Warn on discarding
	non-empty dynamic section.
	(ppc_build_one_stub): Take elf_gp from output bfd, not output
	section owner.
	(ppc_size_one_stub, ppc64_elf_next_toc_section): Likewise.
ld/
	* testsuite/ld-elf/note-3.t: Don't discard .got.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 1c9edaf7c7bf7319ba390f7b992ae2440e2c989f..ea8efcf16a781b8b74b9b46b6204b25cf9a9e62a 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,12 @@
+2017-11-14  Alan Modra  <amodra@gmail.com>
+
+       PR 22431
+       * elf64-ppc.c (ppc64_elf_size_dynamic_sections): Warn on discarding
+       non-empty dynamic section.
+       (ppc_build_one_stub): Take elf_gp from output bfd, not output
+       section owner.
+       (ppc_size_one_stub, ppc64_elf_next_toc_section): Likewise.
+
 2017-11-14  Alan Modra  <amodra@gmail.com>
 
        * elf64-ppc.c (ppc64_elf_size_stubs): Correct test for user

diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 31ee4123b8e7713e07a3475e760ff1c7ca0839dc..8a48848eb27bb8fb2de2f86fd566d8408dfa4f0f 100644 (file)
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -10202,6 +10202,10 @@ ppc64_elf_size_dynamic_sections (bfd *output_bfd,
          continue;
        }
 
+      if (bfd_is_abs_section (s->output_section))
+       _bfd_error_handler (_("warning: discarding dynamic section %s"),
+                           s->name);
+
       if ((s->flags & SEC_HAS_CONTENTS) == 0)
        continue;
 
@@ -10996,7 +11000,7 @@ ppc_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
              + htab->brlt->output_section->vma);
 
       off = (dest
-            - elf_gp (htab->brlt->output_section->owner)
+            - elf_gp (info->output_bfd)
             - htab->sec_info[stub_entry->group->link_sec->id].toc_off);
 
       if (off + 0x80008000 > 0xffffffff || (off & 7) != 0)
@@ -11147,7 +11151,7 @@ ppc_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
        }
 
       off = (dest
-            - elf_gp (plt->output_section->owner)
+            - elf_gp (info->output_bfd)
             - htab->sec_info[stub_entry->group->link_sec->id].toc_off);
 
       if (off + 0x80008000 > 0xffffffff || (off & 7) != 0)
@@ -11295,7 +11299,7 @@ ppc_size_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
        plt = htab->elf.iplt;
       off += (plt->output_offset
              + plt->output_section->vma
-             - elf_gp (plt->output_section->owner)
+             - elf_gp (info->output_bfd)
              - htab->sec_info[stub_entry->group->link_sec->id].toc_off);
 
       size = plt_stub_size (htab, stub_entry, off);
@@ -11398,7 +11402,7 @@ ppc_size_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
          off = (br_entry->offset
                 + htab->brlt->output_offset
                 + htab->brlt->output_section->vma
-                - elf_gp (htab->brlt->output_section->owner)
+                - elf_gp (info->output_bfd)
                 - htab->sec_info[stub_entry->group->link_sec->id].toc_off);
 
          if (info->emitrelocations)
@@ -11518,7 +11522,7 @@ ppc64_elf_next_toc_section (struct bfd_link_info *info, asection *isec)
         output toc base plus 0x8000.  Making the input elf_gp an
         offset allows us to move the toc as a whole without
         recalculating input elf_gp.  */
-      off = htab->toc_curr - elf_gp (isec->output_section->owner);
+      off = htab->toc_curr - elf_gp (info->output_bfd);
       off += TOC_BASE_OFF;
 
       /* Die if someone uses a linker script that doesn't keep input
@@ -11547,7 +11551,7 @@ ppc64_elf_next_toc_section (struct bfd_link_info *info, asection *isec)
     }
   addr = (htab->toc_first_sec->output_offset
          + htab->toc_first_sec->output_section->vma);
-  off = addr - elf_gp (isec->output_section->owner) + TOC_BASE_OFF;
+  off = addr - elf_gp (info->output_bfd) + TOC_BASE_OFF;
   elf_gp (isec->owner) = off;
 
   return TRUE;

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 634c9903c0714de2295709bea46e36c33f9453cd..fe8603cdd9a5c5cf8a5085fe95580f460e68fe20 100644 (file)
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,7 @@
+2017-11-14  Alan Modra  <amodra@gmail.com>
+
+       * testsuite/ld-elf/note-3.t: Don't discard .got.
+
 2017-11-14  Alan Modra  <amodra@gmail.com>
 
        * testsuite/ld-ifunc/ifunc.exp: Ensure non-PIC tests are really

diff --git a/ld/testsuite/ld-elf/note-3.t b/ld/testsuite/ld-elf/note-3.t
index 47f3fe1c95c4c75656e26e38c6b2a05772a35e4d..30ce59f93b50e88cdbdaba6f28cfd00814f3d44b 100644 (file)
--- a/ld/testsuite/ld-elf/note-3.t
+++ b/ld/testsuite/ld-elf/note-3.t
@@ -18,6 +18,7 @@ SECTIONS
   
   .dynstr : { *(.dynstr) }
   .dynsym : { *(.dynsym) }
+  .got : { *(.got .toc) *(.igot) }
   .got.plt : { *(.got.plt) *(.igot.plt) }
   /DISCARD/ : { *(*) }
 }