[PATCH 2/2] aarch64: update tests for SME

[Yury Khrustalev]

Add test that checks that ZA state is disabled after setjmp and sigsetjmp
Update existing SME test that uses setjmp
---
 sysdeps/aarch64/Makefile           |  4 +-
 sysdeps/aarch64/tst-sme-helper.h   | 39 +++++++++++++++++
 sysdeps/aarch64/tst-sme-jmp.c      | 28 ++----------
 sysdeps/aarch64/tst-sme-za-state.c | 68 ++++++++++++++++++++++++++++++
 4 files changed, 114 insertions(+), 25 deletions(-)
 create mode 100644 sysdeps/aarch64/tst-sme-helper.h
 create mode 100644 sysdeps/aarch64/tst-sme-za-state.c

diff --git a/sysdeps/aarch64/Makefile b/sysdeps/aarch64/Makefile
index 4b7f8a5c07..2cb8f6cebc 100644
--- a/sysdeps/aarch64/Makefile
+++ b/sysdeps/aarch64/Makefile
@@ -75,7 +75,9 @@ sysdep_routines += \
   __alloc_gcs
 
 tests += \
-  tst-sme-jmp
+  tst-sme-jmp \
+  tst-sme-za-state \
+  # tests
 endif
 
 ifeq ($(subdir),malloc)
diff --git a/sysdeps/aarch64/tst-sme-helper.h b/sysdeps/aarch64/tst-sme-helper.h
new file mode 100644
index 0000000000..09dd659aed
--- /dev/null
+++ b/sysdeps/aarch64/tst-sme-helper.h
@@ -0,0 +1,39 @@
+/* Utility functions for SME tests.
+   Copyright (C) 2025 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/>.  */
+
+/* Read SVCR to get SM (bit0) and ZA (bit1) state.  */
+static unsigned long
+get_svcr (void)
+{
+  register unsigned long x0 asm ("x0");
+  asm volatile (
+    ".inst   0xd53b4240  /* mrs     x0, svcr  */\n"
+    : "=r" (x0));
+  return x0;
+}
+
+/* Returns tpidr2.  */
+static void *
+get_tpidr2 (void)
+{
+  register unsigned long x0 asm ("x0");
+  asm volatile (
+    ".inst   0xd53bd0a0  /* mrs     x0, tpidr2_el0  */\n"
+    : "=r"(x0) :: "memory");
+  return (void *) x0;
+}
diff --git a/sysdeps/aarch64/tst-sme-jmp.c b/sysdeps/aarch64/tst-sme-jmp.c
index 62c419f6c1..0be11d44f5 100644
--- a/sysdeps/aarch64/tst-sme-jmp.c
+++ b/sysdeps/aarch64/tst-sme-jmp.c
@@ -27,6 +27,8 @@
 #include <support/support.h>
 #include <support/test-driver.h>
 
+#include "tst-sme-helper.h"
+
 struct blk {
   void *za_save_buffer;
   uint16_t num_za_save_slices;
@@ -56,17 +58,6 @@ start_za (void)
     ".inst   0xd503457f  /* smstart za  */");
 }
 
-/* Read SVCR to get SM (bit0) and ZA (bit1) state.  */
-static unsigned long
-get_svcr (void)
-{
-  register unsigned long x0 asm ("x0");
-  asm volatile (
-    ".inst   0xd53b4240  /* mrs     x0, svcr  */\n"
-    : "=r" (x0));
-  return x0;
-}
-
 /* Load data into ZA byte by byte from p.  */
 static void __attribute__ ((noinline))
 load_za (const void *p)
@@ -97,17 +88,6 @@ set_tpidr2 (struct blk *blk)
     :: "r"(x0) : "memory");
 }
 
-/* Returns tpidr2.  */
-static void *
-get_tpidr2 (void)
-{
-  register unsigned long x0 asm ("x0");
-  asm volatile (
-    ".inst   0xd53bd0a0  /* mrs     x0, tpidr2_el0  */\n"
-    : "=r"(x0) :: "memory");
-  return (void *) x0;
-}
-
 static void
 print_data(const char *msg, void *p)
 {
@@ -168,8 +148,8 @@ longjmp_test (void)
     {
       p = get_tpidr2 ();
       printf ("before longjmp: tp2 = %p\n", p);
-      if (p != &blk)
-	FAIL_EXIT1 ("tpidr2 is clobbered");
+      if (p != NULL)
+	FAIL_EXIT1 ("tpidr2 has not been reset to null");
       do_longjmp (env);
       FAIL_EXIT1 ("longjmp returned");
     }
diff --git a/sysdeps/aarch64/tst-sme-za-state.c b/sysdeps/aarch64/tst-sme-za-state.c
new file mode 100644
index 0000000000..b547674d76
--- /dev/null
+++ b/sysdeps/aarch64/tst-sme-za-state.c
@@ -0,0 +1,68 @@
+/* Test for SME ZA state being cleared on setjmp and longjmp.
+   Copyright (C) 2025 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 <stdio.h>
+#include <setjmp.h>
+#include <sys/auxv.h>
+
+#include <support/check.h>
+#include <support/support.h>
+#include <support/test-driver.h>
+
+#include "tst-sme-helper.h"
+
+static void
+check_sme_za_state (void)
+{
+  unsigned long svcr = get_svcr ();
+  void *tpidr2 = get_tpidr2 ();
+  printf ("svcr = %016lx\n", svcr);
+  printf ("tpidr2 = %016lx\n", (unsigned long)tpidr2);
+  TEST_COMPARE (svcr, 0);
+  TEST_COMPARE ((unsigned long)tpidr2, 0);
+}
+
+static void
+run(void)
+{
+  jmp_buf buf;
+  int ret;
+  if ((ret = setjmp (buf)) == 0)
+    {
+      printf ("ready for long jump\n");
+      check_sme_za_state ();
+      longjmp (buf, 42);
+      TEST_VERIFY (false); // unreachable
+      __builtin_unreachable ();
+    }
+  TEST_COMPARE (ret, 42);
+  printf ("completed long jump\n");
+  check_sme_za_state ();
+}
+
+static int
+do_test (void)
+{
+  unsigned long hwcap2 = getauxval (AT_HWCAP2);
+  if ((hwcap2 & HWCAP2_SME) == 0)
+    return EXIT_UNSUPPORTED;
+  run ();
+  return 0;
+}
+
+#include <support/test-driver.c>
-- 
2.39.5