[PATCH] Mark all weak aliases for copy relocations

Alan Modra amodra@gmail.com
Sun Jan 26 12:24:00 GMT 2020


On Sun, Jan 26, 2020 at 03:09:42PM +1030, Alan Modra wrote:
> Cancel that OK until you fix the following.

Never mind, I'll commit the following tomorrow provided my overnight
test run looks reasonable.  I decided the comment needed fixing too.

Most of the fails were due to different dynamic symbol order.

diff --git a/bfd/elflink.c b/bfd/elflink.c
index 300be3f743..5217528a79 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -13123,7 +13123,7 @@ _bfd_elf_gc_mark_rsec (struct bfd_link_info *info, asection *sec,
 		       bfd_boolean *start_stop)
 {
   unsigned long r_symndx;
-  struct elf_link_hash_entry *h;
+  struct elf_link_hash_entry *h, *hw;
 
   r_symndx = cookie->rel->r_info >> cookie->r_sym_shift;
   if (r_symndx == STN_UNDEF)
@@ -13143,12 +13143,16 @@ _bfd_elf_gc_mark_rsec (struct bfd_link_info *info, asection *sec,
 	     || h->root.type == bfd_link_hash_warning)
 	h = (struct elf_link_hash_entry *) h->root.u.i.link;
       h->mark = 1;
-      /* If this symbol is weak and there is a non-weak definition, we
-	 keep the non-weak definition because many backends put
-	 dynamic reloc info on the non-weak definition for code
-	 handling copy relocs.  */
-      if (h->is_weakalias)
-	weakdef (h)->mark = 1;
+      /* Keep all aliases of the symbol too.  If an object symbol
+	 needs to be copied into .dynbss then all of its aliases
+	 should be present as dynamic symbols, not just the one used
+	 on the copy relocation.  */
+      hw = h;
+      while (hw->is_weakalias)
+	{
+	  hw = hw->u.alias;
+	  hw->mark = 1;
+	}
 
       if (start_stop != NULL)
 	{
diff --git a/ld/testsuite/ld-elf/pr25458.map b/ld/testsuite/ld-elf/pr25458.map
new file mode 100644
index 0000000000..5578d1fae7
--- /dev/null
+++ b/ld/testsuite/ld-elf/pr25458.map
@@ -0,0 +1,4 @@
+FOO {
+global:
+  __environ; _environ; environ;
+};
diff --git a/ld/testsuite/ld-elf/pr25458.rd b/ld/testsuite/ld-elf/pr25458.rd
new file mode 100644
index 0000000000..d0fc6b9bed
--- /dev/null
+++ b/ld/testsuite/ld-elf/pr25458.rd
@@ -0,0 +1,10 @@
+#...
+Symbol table '\.dynsym' contains [0-9]+ entries:
+ +Num: +Value +Size Type +Bind +Vis +Ndx Name
+#...
+ +[0-9]+: [0-9a-f]+ +(4|8)+ OBJECT +(WEAK|GLOBAL) +DEFAULT +[0-9]+ _*environ@FOO \(2\)
+#...
+ +[0-9]+: [0-9a-f]+ +(4|8)+ OBJECT +(WEAK|GLOBAL) +DEFAULT +[0-9]+ _*environ@FOO \(2\)
+#...
+ +[0-9]+: [0-9a-f]+ +(4|8)+ OBJECT +(WEAK|GLOBAL) +DEFAULT +[0-9]+ _*environ@FOO \(2\)
+#pass
diff --git a/ld/testsuite/ld-elf/pr25458a.s b/ld/testsuite/ld-elf/pr25458a.s
new file mode 100644
index 0000000000..59e6af2c19
--- /dev/null
+++ b/ld/testsuite/ld-elf/pr25458a.s
@@ -0,0 +1,6 @@
+	.text
+	.globl	_start
+	.type	_start, %function
+_start:
+	.dc.a	environ
+	.size	_start, .-_start
diff --git a/ld/testsuite/ld-elf/pr25458b.s b/ld/testsuite/ld-elf/pr25458b.s
new file mode 100644
index 0000000000..ff64cc7584
--- /dev/null
+++ b/ld/testsuite/ld-elf/pr25458b.s
@@ -0,0 +1,11 @@
+	.data
+	.globl __environ
+	.type __environ,%object
+__environ:
+	.dc.a	0
+	.size	__environ, .-__environ
+	.weak _environ
+	.globl _environ
+	.set _environ, __environ
+	.weak environ
+	.set environ, __environ
diff --git a/ld/testsuite/ld-elf/shared.exp b/ld/testsuite/ld-elf/shared.exp
index e03906a142..c56df1243c 100644
--- a/ld/testsuite/ld-elf/shared.exp
+++ b/ld/testsuite/ld-elf/shared.exp
@@ -337,6 +337,38 @@ if { [check_gc_sections_available] } {
 	    "pr22150" \
 	] \
     ]
+
+    switch $target_triplet {
+	# exclude targets that don't support copy relocs
+	{ bfin-*-* } { }
+	{ frv-*-* } { }
+	{ lm32-*-* } { }
+	{ mips*-*-* } { }
+	{ tic6x-*-* } { }
+	{ xtensa-*-* } { }
+	default {
+	    run_ld_link_tests [list \
+		[list \
+		     "Build pr25458.so" \
+		     "$LFLAGS -shared --version-script=pr25458.map" \
+		     "" \
+		     "$AFLAGS_PIC" \
+		     {pr25458b.s} \
+		     {} \
+		     "pr25458.so" \
+		] \
+		[list \
+		     "Build pr25458" \
+		     "$LFLAGS -e _start --gc-sections" \
+		     "tmpdir/pr25458.so" \
+		     "$AFLAGS_PIC" \
+		     {pr25458a.s} \
+		     {{readelf {--dyn-sym --wide} pr25458.rd}} \
+		     "pr25458" \
+		] \
+	    ]
+	}
+    }
 }
 
 set ASFLAGS $old_ASFLAGS

-- 
Alan Modra
Australia Development Lab, IBM



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