From: Martin Liska <mliska@suse.cz>
Date: Thu, 13 Apr 2017 11:51:28 +0000 (+0200)
Subject: Do not call memcpy with a NULL argument (PR gcov-profile/80413).
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=0040ecb07f44769025a4d8e4952e8dd7b6d5149e;p=gcc.git

Do not call memcpy with a NULL argument (PR gcov-profile/80413).

2017-04-13  Martin Liska  <mliska@suse.cz>

	PR gcov-profile/80413
	* gcov-io.c (gcov_write_string): Copy to buffer just when
	allocated size is greater than zero.

From-SVN: r246903
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8918882fe42..740ca666456 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2017-04-13  Martin Liska  <mliska@suse.cz>
+
+	PR gcov-profile/80413
+	* gcov-io.c (gcov_write_string): Copy to buffer just when
+	allocated size is greater than zero.
+
 2017-04-13  Jakub Jelinek  <jakub@redhat.com>
 
 	PR debug/80321
diff --git a/gcc/gcov-io.c b/gcc/gcov-io.c
index 3b6b022d143..64dedd5528e 100644
--- a/gcc/gcov-io.c
+++ b/gcc/gcov-io.c
@@ -347,8 +347,12 @@ gcov_write_string (const char *string)
   buffer = gcov_write_words (1 + alloc);
 
   buffer[0] = alloc;
-  buffer[alloc] = 0;
-  memcpy (&buffer[1], string, length);
+
+  if (alloc > 0)
+    {
+      buffer[alloc] = 0; /* place nul terminators.  */
+      memcpy (&buffer[1], string, length);
+    }
 }
 #endif