[PATCH 2/6] aarch64: Fix .unreq of predefined aliases

[Alice Carlotti]

Attempting to free a static reg_entry is invalid, so use
insert_reg_alias to create a dynamic copy of the content.


diff --git a/gas/config/tc-aarch64.c b/gas/config/tc-aarch64.c
index 5e92007007310b9f12f1f0051890839216666c17..7af05abbb5c777de1e7e3fa9e9f910a9719a152e 100644
--- a/gas/config/tc-aarch64.c
+++ b/gas/config/tc-aarch64.c
@@ -1599,7 +1599,7 @@ parse_simd_vector_with_bit_index (char **ccp, struct vector_type_el *typeinfo)
 /* Directives: register aliases.  */
 
 static reg_entry *
-insert_reg_alias (char *str, int number, aarch64_reg_type type)
+insert_reg_alias (const char *str, int number, aarch64_reg_type type)
 {
   reg_entry *new;
   const char *name;
@@ -10589,8 +10589,17 @@ md_begin (void)
 			aarch64_sys_regs_sr + i);
 
   for (i = 0; i < ARRAY_SIZE (reg_names); i++)
-    checked_hash_insert (aarch64_reg_hsh, reg_names[i].name,
-			 reg_names + i);
+    {
+      if (reg_names[i].builtin)
+	checked_hash_insert (aarch64_reg_hsh, reg_names[i].name,
+			     reg_names + i);
+      else
+	/* Aliases need to be safely removable, so create a copy of
+	   the reg_entry data.  */
+	insert_reg_alias (reg_names[i].name, reg_names[i].number,
+			  reg_names[i].type);
+    }
+
 
   for (i = 0; i < ARRAY_SIZE (nzcv_names); i++)
     checked_hash_insert (aarch64_nzcv_hsh, nzcv_names[i].template,
diff --git a/gas/testsuite/gas/aarch64/register_aliases.s b/gas/testsuite/gas/aarch64/register_aliases.s
index 856be5699ce434e41d52923020dcbc615208f983..10ee6d189170f6692cfe8e5f2c725fe138c72827 100644
--- a/gas/testsuite/gas/aarch64/register_aliases.s
+++ b/gas/testsuite/gas/aarch64/register_aliases.s
@@ -10,3 +10,9 @@
 	str 	IP0, [fp]
 	ldr	IP1, [fp]
 	str	zero, [x0]
+
+	# Removing builtin register aliases should not segfault.
+	.unreq lr
+	.unreq fp
+	.unreq ip0
+	.unreq ip1