commit d093b677c36ef4b360bf30483b68b95d9f0ad1d2

Author: Noah Goldstein <goldstein.w.n@gmail.com>

Date:   Fri Feb 18 14:19:15 2022 -0600

    x86: Test wcscmp RTM in the wcsncmp overflow case [BZ #28896]

    In the overflow fallback strncmp-avx2-rtm and wcsncmp-avx2-rtm would

    call strcmp-avx2 and wcscmp-avx2 respectively. This would have

    not checks around vzeroupper and would trigger spurious

    aborts. This commit fixes that.

    test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass on

    AVX2 machines with and without RTM.

    Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

    (cherry picked from commit 7835d611af0854e69a0c71e3806f8fe379282d6f)

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

index af934d6ccf1fa337..cd94e683afd5b4a4 100644

--- a/sysdeps/x86/Makefile

+++ b/sysdeps/x86/Makefile

@@ -95,7 +95,9 @@ tests += \

   tst-strcpy-rtm \

   tst-strlen-rtm \

   tst-strncmp-rtm \

-  tst-strrchr-rtm

+  tst-strrchr-rtm \

+  tst-wcsncmp-rtm \

+# tests

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

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

@@ -107,6 +109,7 @@ CFLAGS-tst-strcpy-rtm.c += -mrtm

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

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

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

+CFLAGS-tst-wcsncmp-rtm.c += -mrtm -Wno-error

 endif

 ifneq ($(enable-cet),no)

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

index 4d0004b58aae428d..4e9f094f39c72f67 100644

--- a/sysdeps/x86/tst-strncmp-rtm.c

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

@@ -19,18 +19,32 @@

 #include <stdint.h>

 #include <tst-string-rtm.h>

+#ifdef WIDE

+# define CHAR wchar_t

+# define MEMSET wmemset

+# define STRNCMP wcsncmp

+# define TEST_NAME wcsncmp

+#else /* !WIDE */

+# define CHAR char

+# define MEMSET memset

+# define STRNCMP strncmp

+# define TEST_NAME strncmp

+#endif /* !WIDE */

+

+

+

 #define LOOP 3000

 #define STRING_SIZE 1024

-char string1[STRING_SIZE];

-char string2[STRING_SIZE];

+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)

+  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;

@@ -40,7 +54,7 @@ __attribute__ ((noinline, noclone))

 static int

 function (void)

 {

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

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

     return 0;

   else

     return 1;

@@ -50,7 +64,7 @@ __attribute__ ((noinline, noclone))

 static int

 function_overflow (void)

 {

-  if (strncmp (string1, string2, SIZE_MAX) == 0)

+  if (STRNCMP (string1, string2, SIZE_MAX) == 0)

     return 0;

   else

     return 1;

@@ -59,9 +73,9 @@ function_overflow (void)

 static int

 do_test (void)

 {

-  int status = do_test_1 ("strncmp", LOOP, prepare, function);

+  int status = do_test_1 (TEST_NAME, LOOP, prepare, function);

   if (status != EXIT_SUCCESS)

     return status;

-  status = do_test_1 ("strncmp", LOOP, prepare, function_overflow);

+  status = do_test_1 (TEST_NAME, LOOP, prepare, function_overflow);

   return status;

 }

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

new file mode 100644

index 0000000000000000..bad3b863782c5e56

--- /dev/null

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

@@ -0,0 +1,21 @@

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

+   Copyright (C) 2022 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/>.  */

+

+#define WIDE 1

+#include <wchar.h>

+#include "tst-strncmp-rtm.c"