From: Alan Modra <amodra@gmail.com>
Date: Tue, 2 Nov 2021 08:31:06 +0000 (+1030)
Subject: PR28523, ld.bfd created undefined symbols on ppc64
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=a442059f66075e4e503c43b119cc8b7de04e5718;p=binutils-gdb.git

PR28523, ld.bfd created undefined symbols on ppc64

This patch removes any fake (linker created) function descriptor
symbol if its code entry symbol isn't dynamic, to ensure bogus dynamic
symbols are not created.  The change to func_desc_adjust requires that
it be run only once, which means ppc64_elf_tls_setup can't call it for
just a few selected symbols.

	PR 28523
	* elf64-ppc.c (func_desc_adjust): If a function entry sym is
	not dynamic and has no plt entry, hide any associated fake
	function descriptor symbol.
	(ppc64_elf_edit): Move func_desc_adjust iteration over syms to..
	(ppc64_elf_tls_setup): ..here.
---

diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 4ebacbd9945..40ae96b00d5 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -6281,7 +6281,8 @@ tls_get_addr_epilogue (bfd *obfd, bfd_byte *p, struct ppc_link_hash_table *htab)
 
 /* Called via elf_link_hash_traverse to transfer dynamic linking
    information on function code symbol entries to their corresponding
-   function descriptor symbol entries.  */
+   function descriptor symbol entries.  Must not be called twice for
+   any given code symbol.  */
 
 static bool
 func_desc_adjust (struct elf_link_hash_entry *h, void *inf)
@@ -6339,7 +6340,11 @@ func_desc_adjust (struct elf_link_hash_entry *h, void *inf)
 	if (ent->plt.refcount > 0)
 	  break;
       if (ent == NULL)
-	return true;
+	{
+	  if (fdh != NULL && fdh->fake)
+	    _bfd_elf_link_hash_hide_symbol (info, &fdh->elf, true);
+	  return true;
+	}
     }
 
   /* Create a descriptor as undefined if necessary.  */
@@ -6464,12 +6469,6 @@ ppc64_elf_edit (bfd *obfd ATTRIBUTE_UNUSED, struct bfd_link_info *info)
 	= (htab->elf.hgot->other & ~ELF_ST_VISIBILITY (-1)) | STV_HIDDEN;
     }
 
-  if (htab->need_func_desc_adj)
-    {
-      elf_link_hash_traverse (&htab->elf, func_desc_adjust, info);
-      htab->need_func_desc_adj = 0;
-    }
-
   return true;
 }
 
@@ -7783,6 +7782,13 @@ ppc64_elf_tls_setup (struct bfd_link_info *info)
   if (htab == NULL)
     return false;
 
+  /* Move dynamic linking info to the function descriptor sym.  */
+  if (htab->need_func_desc_adj)
+    {
+      elf_link_hash_traverse (&htab->elf, func_desc_adjust, info);
+      htab->need_func_desc_adj = 0;
+    }
+
   if (abiversion (info->output_bfd) == 1)
     htab->opd_abi = 1;
 
@@ -7830,10 +7836,6 @@ ppc64_elf_tls_setup (struct bfd_link_info *info)
   tga = elf_link_hash_lookup (&htab->elf, ".__tls_get_addr",
 			      false, false, true);
   htab->tls_get_addr = ppc_elf_hash_entry (tga);
-
-  /* Move dynamic linking info to the function descriptor sym.  */
-  if (tga != NULL)
-    func_desc_adjust (tga, info);
   tga_fd = elf_link_hash_lookup (&htab->elf, "__tls_get_addr",
 				 false, false, true);
   htab->tls_get_addr_fd = ppc_elf_hash_entry (tga_fd);
@@ -7841,8 +7843,6 @@ ppc64_elf_tls_setup (struct bfd_link_info *info)
   desc = elf_link_hash_lookup (&htab->elf, ".__tls_get_addr_desc",
 			       false, false, true);
   htab->tga_desc = ppc_elf_hash_entry (desc);
-  if (desc != NULL)
-    func_desc_adjust (desc, info);
   desc_fd = elf_link_hash_lookup (&htab->elf, "__tls_get_addr_desc",
 				  false, false, true);
   htab->tga_desc_fd = ppc_elf_hash_entry (desc_fd);
@@ -7853,8 +7853,6 @@ ppc64_elf_tls_setup (struct bfd_link_info *info)
 
       opt = elf_link_hash_lookup (&htab->elf, ".__tls_get_addr_opt",
 				  false, false, true);
-      if (opt != NULL)
-	func_desc_adjust (opt, info);
       opt_fd = elf_link_hash_lookup (&htab->elf, "__tls_get_addr_opt",
 				     false, false, true);
       if (opt_fd != NULL