MDEV-35738 mariadb build -fsanitize=pointer-compare

invalid pointer pairs are when the length/memory of one string are
intermixed with another.

For comp_err, the end null pointer was compared to soffset within
my_strtoll10. As we didn't need the end position a NULL arg option
was compatble.

For uca-dump, Address Sanitizer raises invalid pointer pair because
argv options (opt) don't have an obvious correlation of having a start
at opt_X.length, even though the lstrncmp makes this true.

The DBUG_ASSERTS of strmov (added MDEV-11752) where incompatible with
pointer-compare. Replaced strmov with static inline version in
m_string.h using memmove that allows overlaps, and being inline allows
the uneeded parts of the implementation to be optimized away.

extra/comp_err.c

@@ -623,7 +623,7 @@ static uint parse_input_file(const char *file_name, struct errors **top_error,
 
 static uint parse_error_offset(char *str)
 {
-  char *soffset, *end;
+  char *soffset;
   int error;
   uint ioffset;
 
@@ -651,8 +651,7 @@ static uint parse_error_offset(char *str)
   }
   DBUG_PRINT("info", ("str: %s", str));
 
-  end= 0;
-  ioffset= (uint) my_strtoll10(soffset, &end, &error);
+  ioffset= (uint) my_strtoll10(soffset, NULL, &error);
   my_free(soffset);
   DBUG_RETURN(ioffset);
 }

include/m_string.h

@@ -65,13 +65,23 @@
 extern "C" {
 #endif
 
-#ifdef DBUG_OFF
 #if defined(HAVE_STPCPY) && defined(__GNUC__) && !defined(__INTEL_COMPILER)
 #define strmov(A,B) __builtin_stpcpy((A),(B))
 #elif defined(HAVE_STPCPY)
 #define strmov(A,B) stpcpy((A),(B))
-#endif
-#endif
+#else
+__attribute__((nonnull))
+static inline char *strmov(char *dst, const char *src)
+{
+  size_t l;
+  DBUG_ASSERT(dst != NULL);
+  DBUG_ASSERT(src != NULL);
+
+  l= strlen(src);
+  memmove(dst, src, l + 1);
+  return dst + l;
+}
+#endif /* strmov */
 
 /* Declared in int2str() */
 extern const char _dig_vec_upper[];

strings/CMakeLists.txt

@@ -24,7 +24,7 @@ SET(STRINGS_SOURCES bchange.c bmove_upp.c ctype-big5.c ctype-bin.c ctype-cp932.c
                 ctype-ucs2.c ctype-ujis.c ctype-utf8.c ctype-win1250ch.c ctype.c decimal.c dtoa.c int2str.c
                 ctype-unidata.c
                 is_prefix.c llstr.c longlong2str.c my_strtoll10.c my_vsnprintf.c
-                str2int.c strcend.c strend.c strfill.c strmake.c strmov.c strnmov.c
+                str2int.c strcend.c strend.c strfill.c strmake.c strnmov.c
                 strxmov.c strxnmov.c xml.c
                 strmov_overlapp.c
 		my_strchr.c strcont.c strappend.c json_lib.c json_normalize.c)

strings/strmov.c

@@ -1,48 +0,0 @@
-/* Copyright (c) 2000 TXT DataKonsult Ab & Monty Program Ab
-   Copyright (c) 2009-2011, Monty Program Ab
-
-   Redistribution and use in source and binary forms, with or without
-   modification, are permitted provided that the following conditions are
-   met:
-
-   1. Redistributions of source code must retain the above copyright
-   notice, this list of conditions and the following disclaimer.
-
-   2. Redistributions in binary form must the following disclaimer in
-     the documentation and/or other materials provided with the
-     distribution.
-
-   THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND ANY
-   EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
-   PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> OR
-   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
-   USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-   ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
-   OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
-   OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-   SUCH DAMAGE.
-*/
-
-/*
-  strmov(dst, src) moves all the  characters  of  src  (including  the
-  closing NUL) to dst, and returns a pointer to the new closing NUL in
-  dst.	 The similar UNIX routine strcpy returns the old value of dst,
-  which I have never found useful.  strmov(strmov(dst,a),b) moves a//b
-  into dst, which seems useful.
-*/
-
-#include "strings_def.h"
-
-#ifndef strmov
-
-char *strmov(register char *dst, register const char *src)
-{
-  DBUG_ASSERT(src + strlen(src) < dst || dst + strlen(src) < src);
-  while ((*dst++ = *src++)) ;
-  return dst-1;
-}
-
-#endif /* strmov */

strings/uca-dump.c

@@ -417,14 +417,20 @@ static int process_option(OPT *options, const char *opt)
   static const LEX_CSTRING opt_levels= {STRING_WITH_LEN("--levels=")};
   static const LEX_CSTRING opt_no_contractions= {STRING_WITH_LEN("--no-contractions")};
   static const LEX_CSTRING opt_case_first= {STRING_WITH_LEN("--case-first=")};
+  const char *eq= strchr(opt, '=');
   if (!lstrncmp(opt, opt_name_prefix))
   {
-    options->name_prefix= opt + opt_name_prefix.length;
+    if (!eq)
+      return 1;
+
+    options->name_prefix= eq + 1;
     return 0;
   }
   if (!lstrncmp(opt, opt_levels))
   {
-    options->levels= (uint) strtoul(opt + opt_levels.length, NULL, 10);
+    if (!eq)
+      return 1;
+    options->levels= (uint) strtoul(eq + 1, NULL, 10);
     if (options->levels < 1 || options->levels > 3)
     {
       printf("Bad --levels value\n");
@@ -434,13 +440,15 @@ static int process_option(OPT *options, const char *opt)
   }
   if (!lstrncmp(opt, opt_case_first))
   {
-    const char *value= opt + opt_case_first.length;
-    if (!strcasecmp(value, "upper"))
+    if (!eq)
+      return 1;
+    eq++;
+    if (!strcasecmp(eq, "upper"))
     {
       options->case_first_upper= TRUE;
       return 0;
     }
-    if (!strcasecmp(value, "lower"))
+    if (!strcasecmp(eq, "lower"))
     {
       options->case_first_upper= FALSE;
       return 0;