From 294c22ed9aa3f576f58b9af69c9a34225fcf02aa Mon Sep 17 00:00:00 2001

From: "H.J. Lu" <hjl.tools@gmail.com>

Date: Tue, 23 Feb 2021 06:33:10 -0800

Subject: [PATCH] x86: Add string/memory function tests in RTM region

At function exit, AVX optimized string/memory functions have VZEROUPPER

which triggers RTM abort.   When such functions are called inside a

transactionally executing RTM region, RTM abort causes severe performance

degradation.  Add tests to verify that string/memory functions won't

cause RTM abort in RTM region.

(cherry picked from commit 4bd660be40967cd69072f69ebc2ad32bfcc1f206)

---

 sysdeps/x86/Makefile          | 23 +++++++++++

 sysdeps/x86/tst-memchr-rtm.c  | 54 ++++++++++++++++++++++++++

 sysdeps/x86/tst-memcmp-rtm.c  | 52 +++++++++++++++++++++++++

 sysdeps/x86/tst-memmove-rtm.c | 53 ++++++++++++++++++++++++++

 sysdeps/x86/tst-memrchr-rtm.c | 54 ++++++++++++++++++++++++++

 sysdeps/x86/tst-memset-rtm.c  | 45 ++++++++++++++++++++++

 sysdeps/x86/tst-strchr-rtm.c  | 54 ++++++++++++++++++++++++++

 sysdeps/x86/tst-strcpy-rtm.c  | 53 ++++++++++++++++++++++++++

 sysdeps/x86/tst-string-rtm.h  | 72 +++++++++++++++++++++++++++++++++++

 sysdeps/x86/tst-strlen-rtm.c  | 53 ++++++++++++++++++++++++++

 sysdeps/x86/tst-strncmp-rtm.c | 52 +++++++++++++++++++++++++

 sysdeps/x86/tst-strrchr-rtm.c | 53 ++++++++++++++++++++++++++

 12 files changed, 618 insertions(+)

 create mode 100644 sysdeps/x86/tst-memchr-rtm.c

 create mode 100644 sysdeps/x86/tst-memcmp-rtm.c

 create mode 100644 sysdeps/x86/tst-memmove-rtm.c

 create mode 100644 sysdeps/x86/tst-memrchr-rtm.c

 create mode 100644 sysdeps/x86/tst-memset-rtm.c

 create mode 100644 sysdeps/x86/tst-strchr-rtm.c

 create mode 100644 sysdeps/x86/tst-strcpy-rtm.c

 create mode 100644 sysdeps/x86/tst-string-rtm.h

 create mode 100644 sysdeps/x86/tst-strlen-rtm.c

 create mode 100644 sysdeps/x86/tst-strncmp-rtm.c

 create mode 100644 sysdeps/x86/tst-strrchr-rtm.c

diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile

index 59e928e9..5be71ada 100644

--- a/sysdeps/x86/Makefile

+++ b/sysdeps/x86/Makefile

@@ -17,6 +17,29 @@ endif

 ifeq ($(subdir),string)

 sysdep_routines += cacheinfo

+

+tests += \

+  tst-memchr-rtm \

+  tst-memcmp-rtm \

+  tst-memmove-rtm \

+  tst-memrchr-rtm \

+  tst-memset-rtm \

+  tst-strchr-rtm \

+  tst-strcpy-rtm \

+  tst-strlen-rtm \

+  tst-strncmp-rtm \

+  tst-strrchr-rtm

+

+CFLAGS-tst-memchr-rtm.c += -mrtm

+CFLAGS-tst-memcmp-rtm.c += -mrtm

+CFLAGS-tst-memmove-rtm.c += -mrtm

+CFLAGS-tst-memrchr-rtm.c += -mrtm

+CFLAGS-tst-memset-rtm.c += -mrtm

+CFLAGS-tst-strchr-rtm.c += -mrtm

+CFLAGS-tst-strcpy-rtm.c += -mrtm

+CFLAGS-tst-strlen-rtm.c += -mrtm

+CFLAGS-tst-strncmp-rtm.c += -mrtm

+CFLAGS-tst-strrchr-rtm.c += -mrtm

 endif

 ifneq ($(enable-cet),no)

diff --git a/sysdeps/x86/tst-memchr-rtm.c b/sysdeps/x86/tst-memchr-rtm.c

new file mode 100644

index 00000000..e4749401

--- /dev/null

+++ b/sysdeps/x86/tst-memchr-rtm.c

@@ -0,0 +1,54 @@

+/* Test case for memchr inside a transactionally executing RTM region.

+   Copyright (C) 2021 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <https://www.gnu.org/licenses/>.  */

+

+#include <tst-string-rtm.h>

+

+#define LOOP 3000

+#define STRING_SIZE 1024

+char string1[STRING_SIZE];

+

+__attribute__ ((noinline, noclone))

+static int

+prepare (void)

+{

+  memset (string1, 'a', STRING_SIZE);

+  string1[100] = 'c';

+  string1[STRING_SIZE - 100] = 'c';

+  char *p = memchr (string1, 'c', STRING_SIZE);

+  if (p == &string1[100])

+    return EXIT_SUCCESS;

+  else

+    return EXIT_FAILURE;

+}

+

+__attribute__ ((noinline, noclone))

+static int

+function (void)

+{

+  char *p = memchr (string1, 'c', STRING_SIZE);

+  if (p == &string1[100])

+    return 0;

+  else

+    return 1;

+}

+

+static int

+do_test (void)

+{

+  return do_test_1 ("memchr", LOOP, prepare, function);

+}

diff --git a/sysdeps/x86/tst-memcmp-rtm.c b/sysdeps/x86/tst-memcmp-rtm.c

new file mode 100644

index 00000000..e4c8a623

--- /dev/null

+++ b/sysdeps/x86/tst-memcmp-rtm.c

@@ -0,0 +1,52 @@

+/* Test case for memcmp inside a transactionally executing RTM region.

+   Copyright (C) 2021 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <https://www.gnu.org/licenses/>.  */

+

+#include <tst-string-rtm.h>

+

+#define LOOP 3000

+#define STRING_SIZE 1024

+char string1[STRING_SIZE];

+char string2[STRING_SIZE];

+

+__attribute__ ((noinline, noclone))

+static int

+prepare (void)

+{

+  memset (string1, 'a', STRING_SIZE);

+  memset (string2, 'a', STRING_SIZE);

+  if (memcmp (string1, string2, STRING_SIZE) == 0)

+    return EXIT_SUCCESS;

+  else

+    return EXIT_FAILURE;

+}

+

+__attribute__ ((noinline, noclone))

+static int

+function (void)

+{

+  if (memcmp (string1, string2, STRING_SIZE) == 0)

+    return 0;

+  else

+    return 1;

+}

+

+static int

+do_test (void)

+{

+  return do_test_1 ("memcmp", LOOP, prepare, function);

+}

diff --git a/sysdeps/x86/tst-memmove-rtm.c b/sysdeps/x86/tst-memmove-rtm.c

new file mode 100644

index 00000000..4bf97ef1

--- /dev/null

+++ b/sysdeps/x86/tst-memmove-rtm.c

@@ -0,0 +1,53 @@

+/* Test case for memmove inside a transactionally executing RTM region.

+   Copyright (C) 2021 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <https://www.gnu.org/licenses/>.  */

+

+#include <tst-string-rtm.h>

+

+#define LOOP 3000

+#define STRING_SIZE 1024

+char string1[STRING_SIZE];

+char string2[STRING_SIZE];

+

+__attribute__ ((noinline, noclone))

+static int

+prepare (void)

+{

+  memset (string1, 'a', STRING_SIZE);

+  if (memmove (string2, string1, STRING_SIZE) == string2

+      && memcmp (string2, string1, STRING_SIZE) == 0)

+    return EXIT_SUCCESS;

+  else

+    return EXIT_FAILURE;

+}

+

+__attribute__ ((noinline, noclone))

+static int

+function (void)

+{

+  if (memmove (string2, string1, STRING_SIZE) == string2

+      && memcmp (string2, string1, STRING_SIZE) == 0)

+    return 0;

+  else

+    return 1;

+}

+

+static int

+do_test (void)

+{

+  return do_test_1 ("memmove", LOOP, prepare, function);

+}

diff --git a/sysdeps/x86/tst-memrchr-rtm.c b/sysdeps/x86/tst-memrchr-rtm.c

new file mode 100644

index 00000000..a57a5a8e

--- /dev/null

+++ b/sysdeps/x86/tst-memrchr-rtm.c

@@ -0,0 +1,54 @@

+/* Test case for memrchr inside a transactionally executing RTM region.

+   Copyright (C) 2021 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <https://www.gnu.org/licenses/>.  */

+

+#include <tst-string-rtm.h>

+

+#define LOOP 3000

+#define STRING_SIZE 1024

+char string1[STRING_SIZE];

+

+__attribute__ ((noinline, noclone))

+static int

+prepare (void)

+{

+  memset (string1, 'a', STRING_SIZE);

+  string1[100] = 'c';

+  string1[STRING_SIZE - 100] = 'c';

+  char *p = memrchr (string1, 'c', STRING_SIZE);

+  if (p == &string1[STRING_SIZE - 100])

+    return EXIT_SUCCESS;

+  else

+    return EXIT_FAILURE;

+}

+

+__attribute__ ((noinline, noclone))

+static int

+function (void)

+{

+  char *p = memrchr (string1, 'c', STRING_SIZE);

+  if (p == &string1[STRING_SIZE - 100])

+    return 0;

+  else

+    return 1;

+}

+

+static int

+do_test (void)

+{

+  return do_test_1 ("memrchr", LOOP, prepare, function);

+}

diff --git a/sysdeps/x86/tst-memset-rtm.c b/sysdeps/x86/tst-memset-rtm.c

new file mode 100644

index 00000000..bf343a4d

--- /dev/null

+++ b/sysdeps/x86/tst-memset-rtm.c

@@ -0,0 +1,45 @@

+/* Test case for memset inside a transactionally executing RTM region.

+   Copyright (C) 2021 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <https://www.gnu.org/licenses/>.  */

+

+#include <tst-string-rtm.h>

+

+#define LOOP 3000

+#define STRING_SIZE 1024

+char string1[STRING_SIZE];

+

+__attribute__ ((noinline, noclone))

+static int

+prepare (void)

+{

+  memset (string1, 'a', STRING_SIZE);

+  return EXIT_SUCCESS;

+}

+

+__attribute__ ((noinline, noclone))

+static int

+function (void)

+{

+  memset (string1, 'a', STRING_SIZE);

+  return 0;

+}

+

+static int

+do_test (void)

+{

+  return do_test_1 ("memset", LOOP, prepare, function);

+}

diff --git a/sysdeps/x86/tst-strchr-rtm.c b/sysdeps/x86/tst-strchr-rtm.c

new file mode 100644

index 00000000..a82e29c0

--- /dev/null

+++ b/sysdeps/x86/tst-strchr-rtm.c

@@ -0,0 +1,54 @@

+/* Test case for strchr inside a transactionally executing RTM region.

+   Copyright (C) 2021 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <https://www.gnu.org/licenses/>.  */

+

+#include <tst-string-rtm.h>

+

+#define LOOP 3000

+#define STRING_SIZE 1024

+char string1[STRING_SIZE];

+

+__attribute__ ((noinline, noclone))

+static int

+prepare (void)

+{

+  memset (string1, 'a', STRING_SIZE - 1);

+  string1[100] = 'c';

+  string1[STRING_SIZE - 100] = 'c';

+  char *p = strchr (string1, 'c');

+  if (p == &string1[100])

+    return EXIT_SUCCESS;

+  else

+    return EXIT_FAILURE;

+}

+

+__attribute__ ((noinline, noclone))

+static int

+function (void)

+{

+  char *p = strchr (string1, 'c');

+  if (p == &string1[100])

+    return 0;

+  else

+    return 1;

+}

+

+static int

+do_test (void)

+{

+  return do_test_1 ("strchr", LOOP, prepare, function);

+}

diff --git a/sysdeps/x86/tst-strcpy-rtm.c b/sysdeps/x86/tst-strcpy-rtm.c

new file mode 100644

index 00000000..2b2a583f

--- /dev/null

+++ b/sysdeps/x86/tst-strcpy-rtm.c

@@ -0,0 +1,53 @@

+/* Test case for strcpy inside a transactionally executing RTM region.

+   Copyright (C) 2021 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <https://www.gnu.org/licenses/>.  */

+

+#include <tst-string-rtm.h>

+

+#define LOOP 3000

+#define STRING_SIZE 1024

+char string1[STRING_SIZE];

+char string2[STRING_SIZE];

+

+__attribute__ ((noinline, noclone))

+static int

+prepare (void)

+{

+  memset (string1, 'a', STRING_SIZE - 1);

+  if (strcpy (string2, string1) == string2

+      && strcmp (string2, string1) == 0)

+    return EXIT_SUCCESS;

+  else

+    return EXIT_FAILURE;

+}

+

+__attribute__ ((noinline, noclone))

+static int

+function (void)

+{

+  if (strcpy (string2, string1) == string2

+      && strcmp (string2, string1) == 0)

+    return 0;

+  else

+    return 1;

+}

+

+static int

+do_test (void)

+{

+  return do_test_1 ("strcpy", LOOP, prepare, function);

+}

diff --git a/sysdeps/x86/tst-string-rtm.h b/sysdeps/x86/tst-string-rtm.h

new file mode 100644

index 00000000..d2470afa

--- /dev/null

+++ b/sysdeps/x86/tst-string-rtm.h

@@ -0,0 +1,72 @@

+/* Test string function in a transactionally executing RTM region.

+   Copyright (C) 2021 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <https://www.gnu.org/licenses/>.  */

+

+#include <string.h>

+#include <x86intrin.h>

+#include <sys/platform/x86.h>

+#include <support/check.h>

+#include <support/test-driver.h>

+

+static int

+do_test_1 (const char *name, unsigned int loop, int (*prepare) (void),

+	   int (*function) (void))

+{

+  if (!CPU_FEATURE_USABLE (RTM))

+    return EXIT_UNSUPPORTED;

+

+  int status = prepare ();

+  if (status != EXIT_SUCCESS)

+    return status;

+

+  unsigned int i;

+  unsigned int naborts = 0;

+  unsigned int failed = 0;

+  for (i = 0; i < loop; i++)

+    {

+      failed |= function ();

+      if (_xbegin() == _XBEGIN_STARTED)

+	{

+	  failed |= function ();

+	  _xend();

+	}

+      else

+	{

+	  failed |= function ();

+	  ++naborts;

+	}

+    }

+

+  if (failed)

+    FAIL_EXIT1 ("%s() failed", name);

+

+  if (naborts)

+    {

+      /* NB: Low single digit (<= 5%) noise-level aborts are normal for

+	 TSX.  */

+      double rate = 100 * ((double) naborts) / ((double) loop);

+      if (rate > 5)

+	FAIL_EXIT1 ("TSX abort rate: %.2f%% (%d out of %d)",

+		    rate, naborts, loop);

+    }

+

+  return EXIT_SUCCESS;

+}

+

+static int do_test (void);

+

+#include <support/test-driver.c>

diff --git a/sysdeps/x86/tst-strlen-rtm.c b/sysdeps/x86/tst-strlen-rtm.c

new file mode 100644

index 00000000..0dcf14db

--- /dev/null

+++ b/sysdeps/x86/tst-strlen-rtm.c

@@ -0,0 +1,53 @@

+/* Test case for strlen inside a transactionally executing RTM region.

+   Copyright (C) 2021 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <https://www.gnu.org/licenses/>.  */

+

+#include <tst-string-rtm.h>

+

+#define LOOP 3000

+#define STRING_SIZE 1024

+char string1[STRING_SIZE];

+

+__attribute__ ((noinline, noclone))

+static int

+prepare (void)

+{

+  memset (string1, 'a', STRING_SIZE - 1);

+  string1[STRING_SIZE - 100] = '\0';

+  size_t len = strlen (string1);

+  if (len == STRING_SIZE - 100)

+    return EXIT_SUCCESS;

+  else

+    return EXIT_FAILURE;

+}

+

+__attribute__ ((noinline, noclone))

+static int

+function (void)

+{

+  size_t len = strlen (string1);

+  if (len == STRING_SIZE - 100)

+    return 0;

+  else

+    return 1;

+}

+

+static int

+do_test (void)

+{

+  return do_test_1 ("strlen", LOOP, prepare, function);

+}

diff --git a/sysdeps/x86/tst-strncmp-rtm.c b/sysdeps/x86/tst-strncmp-rtm.c

new file mode 100644

index 00000000..236ad951

--- /dev/null

+++ b/sysdeps/x86/tst-strncmp-rtm.c

@@ -0,0 +1,52 @@

+/* Test case for strncmp inside a transactionally executing RTM region.

+   Copyright (C) 2021 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <https://www.gnu.org/licenses/>.  */

+

+#include <tst-string-rtm.h>

+

+#define LOOP 3000

+#define STRING_SIZE 1024

+char string1[STRING_SIZE];

+char string2[STRING_SIZE];

+

+__attribute__ ((noinline, noclone))

+static int

+prepare (void)

+{

+  memset (string1, 'a', STRING_SIZE - 1);

+  memset (string2, 'a', STRING_SIZE - 1);

+  if (strncmp (string1, string2, STRING_SIZE) == 0)

+    return EXIT_SUCCESS;

+  else

+    return EXIT_FAILURE;

+}

+

+__attribute__ ((noinline, noclone))

+static int

+function (void)

+{

+  if (strncmp (string1, string2, STRING_SIZE) == 0)

+    return 0;

+  else

+    return 1;

+}

+

+static int

+do_test (void)

+{

+  return do_test_1 ("strncmp", LOOP, prepare, function);

+}

diff --git a/sysdeps/x86/tst-strrchr-rtm.c b/sysdeps/x86/tst-strrchr-rtm.c

new file mode 100644

index 00000000..e32bfaf5

--- /dev/null

+++ b/sysdeps/x86/tst-strrchr-rtm.c

@@ -0,0 +1,53 @@

+/* Test case for strrchr inside a transactionally executing RTM region.

+   Copyright (C) 2021 Free Software Foundation, Inc.

+   This file is part of the GNU C Library.

+

+   The GNU C Library is free software; you can redistribute it and/or

+   modify it under the terms of the GNU Lesser General Public

+   License as published by the Free Software Foundation; either

+   version 2.1 of the License, or (at your option) any later version.

+

+   The GNU C Library is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+   Lesser General Public License for more details.

+

+   You should have received a copy of the GNU Lesser General Public

+   License along with the GNU C Library; if not, see

+   <https://www.gnu.org/licenses/>.  */

+

+#include <tst-string-rtm.h>

+

+#define LOOP 3000

+#define STRING_SIZE 1024

+char string1[STRING_SIZE];

+

+__attribute__ ((noinline, noclone))

+static int

+prepare (void)

+{

+  memset (string1, 'a', STRING_SIZE - 1);

+  string1[STRING_SIZE - 100] = 'c';

+  char *p = strrchr (string1, 'c');

+  if (p == &string1[STRING_SIZE - 100])

+    return EXIT_SUCCESS;

+  else

+    return EXIT_FAILURE;

+}

+

+__attribute__ ((noinline, noclone))

+static int