PR25384, PowerPC64 ELFv1 copy relocs against function symbols

Function symbols of course don't normally want .dynbss copies but
with some old versions of gcc they are needed to copy the function
descriptor.  This patch restricts the cases where they are useful to
compilers using dot-symbols, and enables the warning regardless of
whether a PLT entry is emitted in the executable.  PLTs in shared
libraries are affected by a .dynbss copy in the executable.

bfd/
	PR 25384
	* elf64-ppc.c (ELIMINATE_COPY_RELOCS): Update comment.
	(ppc64_elf_adjust_dynamic_symbol): Don't allow .dynbss copies
	of function symbols unless dot symbols are present.  Do warn
	whenever one is created, regardles of whether a PLT entry is
	also emitted for the function symbol.
ld/
	* testsuite/ld-powerpc/ambiguousv1b.d: Adjust expected output.
	* testsuite/ld-powerpc/funref.s: Align func_tab.
	* testsuite/ld-powerpc/funref2.s: Likewise.
	* testsuite/ld-powerpc/funv1.s: Add dot symbols.

5 files changed, 20 insertions, 8 deletions

diff --git a/ld/ChangeLog b/ld/ChangeLog
index ee68a8c..c68d920 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,10 @@
+2020-01-15  Alan Modra  <amodra@gmail.com>
+
+	* testsuite/ld-powerpc/ambiguousv1b.d: Adjust expected output.
+	* testsuite/ld-powerpc/funref.s: Align func_tab.
+	* testsuite/ld-powerpc/funref2.s: Likewise.
+	* testsuite/ld-powerpc/funv1.s: Add dot symbols.
+
 2020-01-14  Lili Cui <lili.cui@intel.com>
 
 	* testsuite/ld-i386/align-branch-1.d: Updated for i686-pc-elf.
diff --git a/ld/testsuite/ld-powerpc/ambiguousv1b.d b/ld/testsuite/ld-powerpc/ambiguousv1b.d
index 9be1371..205f7ea 100644
--- a/ld/testsuite/ld-powerpc/ambiguousv1b.d
+++ b/ld/testsuite/ld-powerpc/ambiguousv1b.d
@@ -3,6 +3,7 @@
 #as: -a64
 #ld: -melf64ppc --emit-stub-syms
 #ld_after_inputfiles: tmpdir/funv1.so
+#warning: .*requires lazy plt linking.*
 #readelf: -rs --wide
 # Check that we do the right thing with funref2.s that doesn't have
 # anything to mark it as ELFv1 or ELFv2.  Since my_func address is
@@ -15,9 +16,9 @@ Relocation section .* contains 1 entry:
 
 Symbol table '\.dynsym' contains 2 entries:
 #...
-.*: 0*[1-9a-f][0-9a-f]*     4 FUNC    GLOBAL DEFAULT   1[23] my_func
+.*: 0*[1-9a-f][0-9a-f]* +24 FUNC +GLOBAL DEFAULT +1[23] my_func
 #...
 Symbol table '\.symtab' contains .* entries:
 #...
-.*: 0*[1-9a-f][0-9a-f]*     4 FUNC    GLOBAL DEFAULT   1[23] my_func
+.*: 0*[1-9a-f][0-9a-f]* +24 FUNC +GLOBAL DEFAULT +1[23] my_func
 #pass
diff --git a/ld/testsuite/ld-powerpc/funref.s b/ld/testsuite/ld-powerpc/funref.s
index 3f7de47..27c1bcf 100644
--- a/ld/testsuite/ld-powerpc/funref.s
+++ b/ld/testsuite/ld-powerpc/funref.s
@@ -1,4 +1,5 @@
  .data
  .globl func_tab
+ .p2align 3
 func_tab:
  .dc.a my_func
diff --git a/ld/testsuite/ld-powerpc/funref2.s b/ld/testsuite/ld-powerpc/funref2.s
index a2bf949..14c58f0 100644
--- a/ld/testsuite/ld-powerpc/funref2.s
+++ b/ld/testsuite/ld-powerpc/funref2.s
@@ -1,4 +1,5 @@
  .section .rodata,"a",@progbits
  .globl func_tab
+ .p2align 3
 func_tab:
  .dc.a my_func
diff --git a/ld/testsuite/ld-powerpc/funv1.s b/ld/testsuite/ld-powerpc/funv1.s
index e79009d..988ad0d 100644
--- a/ld/testsuite/ld-powerpc/funv1.s
+++ b/ld/testsuite/ld-powerpc/funv1.s
@@ -1,10 +1,12 @@
- .globl my_func
- .type my_func,@function
- .section .opd,"aw",@progbits
+# old style ELFv1, with dot-symbols
+ .globl my_func, .my_func
+ .type .my_func, @function
+ .section .opd, "aw", @progbits
 my_func:
- .quad .Lmy_func, .TOC.@tocbase
+ .quad .my_func, .TOC.@tocbase, 0
+ .size my_func, . - my_func
 
  .text
-.Lmy_func:
+.my_func:
  blr
- .size my_func,.-.Lmy_func
+ .size .my_func, . - .my_func