From 42ca1c480a5bca408a54c6a24d2be2c081d121ac Mon Sep 17 00:00:00 2001

From: Andreas Arnez <arnez@linux.ibm.com>

Date: Thu, 19 May 2022 13:54:06 +0200

Subject: [PATCH] Bug 454040 - Add intercept for memmem on s390x

Since memcheck may report false positives in an optimized version of memmem on

s390x, add an intercept for memmem on s390x platforms.

---

 shared/vg_replace_strmem.c | 36 ++++++++++++++++++++++++++++++++++++

 1 file changed, 36 insertions(+)

diff --git a/shared/vg_replace_strmem.c b/shared/vg_replace_strmem.c

index 5396e83be..d28e74206 100644

--- a/shared/vg_replace_strmem.c

+++ b/shared/vg_replace_strmem.c

@@ -103,6 +103,7 @@

    20430 WMEMCHR

    20440 WCSNLEN

    20450 WSTRNCMP

+   20460 MEMMEM

 */

 #if defined(VGO_solaris)

@@ -1785,6 +1786,41 @@ static inline void my_exit ( int x )

 #endif

+/*---------------------- memmem ----------------------*/

+

+#define MEMMEM(soname, fnname) \

+   void* VG_REPLACE_FUNCTION_EZU(20460,soname,fnname) \

+         (const void* haystack, SizeT hlen, const void* needle, SizeT nlen); \

+   void* VG_REPLACE_FUNCTION_EZU(20460,soname,fnname) \

+         (const void* haystack, SizeT hlen, const void* needle, SizeT nlen) \

+   { \

+      const HChar* h = haystack; \

+      const HChar* n = needle; \

+      \

+      /* If the needle is the empty string, match immediately. */ \

+      if (nlen == 0) return CONST_CAST(void *,h); \

+      \

+      HChar n0 = n[0]; \

+      \

+      for (; hlen >= nlen; hlen--, h++) { \

+         if (h[0] != n0) continue; \

+         \

+         UWord i; \

+         for (i = 1; i < nlen; i++) { \

+            if (n[i] != h[i]) \

+               break; \

+         } \

+         if (i == nlen) \

+           return CONST_CAST(HChar *,h); \

+         \

+      } \

+      return NULL; \

+   }

+

+#if defined(VGP_s390x_linux)

+ MEMMEM(VG_Z_LIBC_SONAME,          memmem)

+#endif

+

 /*---------------------- strpbrk ----------------------*/

-- 

2.31.1

From 4d675f309bcd2d4e9e2b9e6f4aba30f85116bb9b Mon Sep 17 00:00:00 2001

From: Mark Wielaard <mark@klomp.org>

Date: Thu, 19 May 2022 18:08:40 -0400

Subject: [PATCH] Add memmem memcheck tests

---

 memcheck/tests/Makefile.am       |  3 ++

 memcheck/tests/filter_memmem     |  5 ++

 memcheck/tests/memmem.c          | 81 ++++++++++++++++++++++++++++++++

 memcheck/tests/memmem.stderr.exp |  2 +

 memcheck/tests/memmem.vgtest     |  3 ++

 5 files changed, 94 insertions(+)

 create mode 100755 memcheck/tests/filter_memmem

 create mode 100644 memcheck/tests/memmem.c

 create mode 100644 memcheck/tests/memmem.stderr.exp

 create mode 100644 memcheck/tests/memmem.vgtest

diff --git a/memcheck/tests/Makefile.am b/memcheck/tests/Makefile.am

index eb9487272..4d181c1ac 100644

--- a/memcheck/tests/Makefile.am

+++ b/memcheck/tests/Makefile.am

@@ -79,6 +79,7 @@ dist_noinst_SCRIPTS = \

 	filter_strchr \

 	filter_varinfo3 \

 	filter_memcheck \

+	filter_memmem \

 	filter_overlaperror \

 	filter_malloc_free \

         filter_sized_delete

@@ -220,6 +221,7 @@ EXTRA_DIST = \

 	memalign2.stderr.exp memalign2.vgtest \

 	memcmptest.stderr.exp memcmptest.stderr.exp2 \

 	memcmptest.stdout.exp memcmptest.vgtest \

+	memmem.stderr.exp memmem.vgtest \

 	mempool.stderr.exp mempool.vgtest \

 	mempool2.stderr.exp mempool2.vgtest \

 	metadata.stderr.exp metadata.stdout.exp metadata.vgtest \

@@ -417,6 +419,7 @@ check_PROGRAMS = \

 	malloc_usable malloc1 malloc2 malloc3 manuel1 manuel2 manuel3 \

 	match-overrun \

 	memalign_test memalign2 memcmptest mempool mempool2 mmaptest \

+	memmem \

 	mismatches new_override metadata \

 	nanoleak_supp nanoleak2 new_nothrow \

 	noisy_child \

diff --git a/memcheck/tests/filter_memmem b/memcheck/tests/filter_memmem

new file mode 100755

index 000000000..f4a40b2d1

--- /dev/null

+++ b/memcheck/tests/filter_memmem

@@ -0,0 +1,5 @@

+#! /bin/sh

+

+# Too many memmem implementations and overrides.

+# So just keep the main file lines.

+./filter_stderr "$@" | grep " main (memmem.c:"

diff --git a/memcheck/tests/memmem.c b/memcheck/tests/memmem.c

new file mode 100644

index 000000000..d627076e3

--- /dev/null

+++ b/memcheck/tests/memmem.c

@@ -0,0 +1,81 @@

+#define _GNU_SOURCE

+#include <assert.h>

+#include <string.h>

+#include <stdlib.h>

+

+/* mallocs an mem block and fills it with A. A needs to be a zero

+   terminated string. The A string chars, minus the terminating zero

+   are copied into the returned mem block.  */

+static void *

+create_mem (const char *a)

+{

+  size_t len = strlen (a);

+  void *mem = malloc (len);

+  memcpy (mem, a, len);

+  return mem;

+}

+

+int

+main ()

+{

+  char *haystack;

+  char *needle;

+

+  haystack = create_mem ("a");

+  needle = create_mem ("a");

+  assert (memmem (haystack, 0, needle, 0) == haystack);

+  assert (memmem (haystack, 1, needle, 0) == haystack);

+  assert (memmem (haystack, 0, needle, 1) == NULL);

+  assert (memmem (haystack, 1, needle, 1) == haystack);

+  free (haystack);

+  free (needle);

+

+  haystack = create_mem ("abc");

+  needle = create_mem ("bc");

+  assert (memmem (haystack, 3, needle, 0) == haystack);

+  assert (memmem (haystack, 3, needle, 2) == haystack + 1);

+  assert (memmem (haystack + 1, 2, needle, 2) == haystack + 1);

+  assert (memmem (haystack + 2, 1, needle, 2) == NULL);

+  free (haystack);

+  free (needle);

+

+  haystack = create_mem ("abcabcabc");

+  needle = create_mem ("bca");

+  assert (memmem (haystack, 9, needle, 3) == haystack + 1);

+  free (haystack);

+  free (needle);

+

+  haystack = create_mem ("abcabcabc");

+  needle = create_mem ("bcad");

+  assert (memmem (haystack, 9, needle, 4) == NULL);

+  free (haystack);

+  free (needle);

+

+  haystack = create_mem ("xxxxxxxxxxxxxxxxxABC");

+  needle = create_mem ("ABCD");

+  assert (memmem (haystack, 20, needle, 2) == haystack + 17);

+  assert (memmem (haystack + 3, 17, needle, 2) == haystack + 17);

+  assert (memmem (haystack + 15, 5, needle, 2) == haystack + 17);

+  assert (memmem (haystack, 20, needle, 3) == haystack + 17);

+  assert (memmem (haystack + 3, 17, needle, 3) == haystack + 17);

+  assert (memmem (haystack + 15, 5, needle, 3) == haystack + 17);

+  assert (memmem (haystack, 20, needle, 4) == NULL);

+  assert (memmem (haystack + 3, 5, needle, 4) == NULL);

+  assert (memmem (haystack + 15, 5, needle, 4) == NULL);

+  free (haystack);

+  free (needle);

+

+  haystack = malloc (1);

+  needle = create_mem ("a");

+  assert (memmem (haystack, 1, needle, 1) == NULL);

+  free (haystack);

+  free (needle);

+

+  haystack = create_mem ("A");

+  needle = malloc (1);

+  assert (memmem (haystack, 1, needle, 1) == NULL);

+  free (haystack);

+  free (needle);

+

+  return 0;

+}

diff --git a/memcheck/tests/memmem.stderr.exp b/memcheck/tests/memmem.stderr.exp

new file mode 100644

index 000000000..b4612fbd4

--- /dev/null

+++ b/memcheck/tests/memmem.stderr.exp

@@ -0,0 +1,2 @@

+   by 0x........: main (memmem.c:70)

+   by 0x........: main (memmem.c:76)

diff --git a/memcheck/tests/memmem.vgtest b/memcheck/tests/memmem.vgtest

new file mode 100644

index 000000000..6d12895df

--- /dev/null

+++ b/memcheck/tests/memmem.vgtest

@@ -0,0 +1,3 @@

+prog: memmem

+vgopts: -q

+stderr_filter: filter_memmem

-- 

2.18.4