[PATCH v2] gdb/record-full: Use xmalloc instead of alloca for temporary memory storage.

["Marcin Kościelnicki" <koriakin@0x04.net>]

On the newly added s390 target, it's possible for a single instruction
to write practically unbounded amount of memory (eg. MVCLE).  This caused
a stack overflow when alloca was used.

gdb/ChangeLog:

	* record-full.c (record_full_exec_insn): Use xmalloc for temporary
	memory storage.
---
Done and done.

 gdb/ChangeLog     | 5 +++++
 gdb/record-full.c | 5 ++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 532535d..5b20fa2 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 2015-11-03  Marcin Kościelnicki  <koriakin@0x04.net>
 
+	* record-full.c (record_full_exec_insn): Use xmalloc for temporary
+	memory storage.
+
+2015-11-03  Marcin Kościelnicki  <koriakin@0x04.net>
+
 	* MAINTAINERS (Write After Approval): Add Marcin Kościelnicki.
 
 2015-10-30  Pedro Alves  <palves@redhat.com>
diff --git a/gdb/record-full.c b/gdb/record-full.c
index 595e357..03b3d41 100644
--- a/gdb/record-full.c
+++ b/gdb/record-full.c
@@ -726,7 +726,8 @@ record_full_exec_insn (struct regcache *regcache,
 	/* Nothing to do if the entry is flagged not_accessible.  */
         if (!entry->u.mem.mem_entry_not_accessible)
           {
-            gdb_byte *mem = (gdb_byte *) alloca (entry->u.mem.len);
+            gdb_byte *mem = (gdb_byte *) xmalloc (entry->u.mem.len);
+            struct cleanup *cleanup = make_cleanup (xfree, mem);
 
             if (record_debug > 1)
               fprintf_unfiltered (gdb_stdlog,
@@ -771,6 +772,8 @@ record_full_exec_insn (struct regcache *regcache,
 		      record_full_stop_reason = TARGET_STOPPED_BY_WATCHPOINT;
 		  }
               }
+
+	    do_cleanups (cleanup);
           }
       }
       break;
-- 
2.6.2