Revision: 743
http://www.exim.org/viewvc/pcre2?view=rev&revision=743
Author: ph10
Date: 2017-04-12 14:48:11 +0100 (Wed, 12 Apr 2017)
Log Message:
-----------
Fix valgrind warnings for unset padding at the end of the pcre2_real_code
structure.
Modified Paths:
--------------
code/trunk/ChangeLog
code/trunk/src/pcre2_compile.c
Modified: code/trunk/ChangeLog
===================================================================
--- code/trunk/ChangeLog 2017-04-12 13:26:23 UTC (rev 742)
+++ code/trunk/ChangeLog 2017-04-12 13:48:11 UTC (rev 743)
@@ -126,7 +126,12 @@
heap limit along with other pattern information, and to find the minimum when
the find_limits modifier is set.
+23. Write to the last 8 bytes of the pcre2_real_code structure when a compiled
+pattern is set up so as to initialize any padding the compiler might have
+included. This avoids valgrind warnings when a compiled pattern is copied, in
+particular when it is serialized.
+
Version 10.23 14-February-2017
------------------------------
Modified: code/trunk/src/pcre2_compile.c
===================================================================
--- code/trunk/src/pcre2_compile.c 2017-04-12 13:26:23 UTC (rev 742)
+++ code/trunk/src/pcre2_compile.c 2017-04-12 13:48:11 UTC (rev 743)
@@ -9283,7 +9283,14 @@
errorcode = ERR21;
goto HAD_CB_ERROR;
}
+
+/* The compiler may put padding at the end of the pcre2_real_code structure in
+order to round it up to a multiple of 4 or 8 bytes. This means that when a
+compiled pattern is copied (for example, when serialized) undefined bytes are
+read, and this annoys debuggers such as valgrind. To avoid this, we explicitly
+write to the last 8 bytes of the structure before setting the fields. */
+memset((char *)re + sizeof(pcre2_real_code) - 8, 0, 8);
re->memctl = ccontext->memctl;
re->tables = tables;
re->executable_jit = NULL;
