[glibc] aarch64: Add longjmp test for SME

[glibc] aarch64: Add longjmp test for SME

[Szabolcs Nagy]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=0c12c8c0cb5450cca69c36991803aef838406d6f

commit 0c12c8c0cb5450cca69c36991803aef838406d6f
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date:   Tue Dec 21 13:49:37 2021 +0000

    aarch64: Add longjmp test for SME
    
    Includes test for setcontext too.
    
    The test directly checks after longjmp if ZA got disabled and the
    ZA contents got saved following the lazy saving scheme. It does not
    use ACLE code to verify that gcc can interoperate with glibc.
    
    Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

Diff:
---
 sysdeps/aarch64/Makefile      |   3 +
 sysdeps/aarch64/tst-sme-jmp.c | 280 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 283 insertions(+)

diff --git a/sysdeps/aarch64/Makefile b/sysdeps/aarch64/Makefile
index 9d8844d9c8..141d7d9cc2 100644
--- a/sysdeps/aarch64/Makefile
+++ b/sysdeps/aarch64/Makefile
@@ -68,6 +68,9 @@ sysdep_routines += \
   __mtag_tag_zero_region \
   __mtag_tag_region \
   __arm_za_disable
+
+tests += \
+  tst-sme-jmp
 endif
 
 ifeq ($(subdir),malloc)
diff --git a/sysdeps/aarch64/tst-sme-jmp.c b/sysdeps/aarch64/tst-sme-jmp.c
new file mode 100644
index 0000000000..35769340e7
--- /dev/null
+++ b/sysdeps/aarch64/tst-sme-jmp.c
@@ -0,0 +1,280 @@
+/* Test for SME longjmp.
+   Copyright (C) 2023 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 <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <setjmp.h>
+#include <ucontext.h>
+#include <sys/auxv.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/test-driver.h>
+
+struct blk {
+  void *za_save_buffer;
+  uint16_t num_za_save_slices;
+  char __reserved[6];
+};
+
+static unsigned long svl;
+static uint8_t *za_orig;
+static uint8_t *za_dump;
+static uint8_t *za_save;
+
+static unsigned long
+get_svl (void)
+{
+  register unsigned long x0 asm ("x0");
+  asm volatile (
+    ".inst   0x04bf5820  /* rdsvl   x0, 1  */\n"
+    : "=r" (x0));
+  return x0;
+}
+
+/* PSTATE.ZA = 1, set ZA state to active.  */
+static void
+start_za (void)
+{
+  asm volatile (
+    ".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)
+{
+  register unsigned long x15 asm ("x15") = 0;
+  register unsigned long x16 asm ("x16") = (unsigned long)p;
+  register unsigned long x17 asm ("x17") = svl;
+
+  asm volatile (
+    ".inst   0xd503437f  /* smstart sm  */\n"
+    ".L_ldr_loop:\n"
+    ".inst   0xe1006200  /* ldr     za[w15, 0], [x16]  */\n"
+    "add     w15, w15, 1\n"
+    ".inst   0x04305030  /* addvl   x16, x16, 1  */\n"
+    "cmp     w15, w17\n"
+    "bne     .L_ldr_loop\n"
+    ".inst   0xd503427f  /* smstop  sm  */\n"
+    : "+r"(x15), "+r"(x16), "+r"(x17));
+}
+
+/* Set tpidr2 to BLK.  */
+static void
+set_tpidr2 (struct blk *blk)
+{
+  register unsigned long x0 asm ("x0") = (unsigned long)blk;
+  asm volatile (
+    ".inst   0xd51bd0a0  /* msr     tpidr2_el0, x0  */\n"
+    :: "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)
+{
+  unsigned char *a = p;
+  printf ("%s:\n", msg);
+  for (int i = 0; i < svl; i++)
+    {
+      printf ("%d: ", i);
+      for (int j = 0; j < svl; j++)
+	printf("%02x,", a[i*svl+j]);
+      printf("\n");
+    }
+  printf(".\n");
+  fflush (stdout);
+}
+
+__attribute__ ((noinline))
+static void
+do_longjmp (jmp_buf env)
+{
+  longjmp (env, 1);
+}
+
+__attribute__ ((noinline))
+static void
+do_setcontext (const ucontext_t *p)
+{
+  setcontext (p);
+}
+
+static void
+longjmp_test (void)
+{
+  unsigned long svcr;
+  jmp_buf env;
+  void *p;
+  int r;
+  struct blk blk = {za_save, svl, {0}};
+
+  printf ("longjmp test:\n");
+  p = get_tpidr2 ();
+  printf ("initial tp2 = %p\n", p);
+  if (p != NULL)
+    FAIL_EXIT1 ("tpidr2 is not initialized to 0");
+  svcr = get_svcr ();
+  if (svcr != 0)
+    FAIL_EXIT1 ("svcr != 0: %lu", svcr);
+  set_tpidr2 (&blk);
+  start_za ();
+  load_za (za_orig);
+
+  print_data ("za save space", za_save);
+  p = get_tpidr2 ();
+  printf ("before setjmp: tp2 = %p\n", p);
+  if (p != &blk)
+    FAIL_EXIT1 ("tpidr2 is not set to BLK %p", (void *)&blk);
+  if (setjmp (env) == 0)
+    {
+      p = get_tpidr2 ();
+      printf ("before longjmp: tp2 = %p\n", p);
+      if (p != &blk)
+	FAIL_EXIT1 ("tpidr2 is clobbered");
+      do_longjmp (env);
+      FAIL_EXIT1 ("longjmp returned");
+    }
+  p = get_tpidr2 ();
+  printf ("after longjmp: tp2 = %p\n", p);
+  if (p != NULL)
+    FAIL_EXIT1 ("tpidr2 is not set to 0");
+  svcr = get_svcr ();
+  if (svcr != 0)
+    FAIL_EXIT1 ("svcr != 0: %lu", svcr);
+  print_data ("za save space", za_save);
+  r = memcmp (za_orig, za_save, svl*svl);
+  if (r != 0)
+    FAIL_EXIT1 ("saving za failed");
+}
+
+static void
+setcontext_test (void)
+{
+  volatile int setcontext_done = 0;
+  unsigned long svcr;
+  ucontext_t ctx;
+  void *p;
+  int r;
+  struct blk blk = {za_save, svl, {0}};
+
+  printf ("setcontext test:\n");
+  p = get_tpidr2 ();
+  printf ("initial tp2 = %p\n", p);
+  if (p != NULL)
+    FAIL_EXIT1 ("tpidr2 is not initialized to 0");
+  svcr = get_svcr ();
+  if (svcr != 0)
+    FAIL_EXIT1 ("svcr != 0: %lu", svcr);
+  set_tpidr2 (&blk);
+  start_za ();
+  load_za (za_orig);
+
+  print_data ("za save space", za_save);
+  p = get_tpidr2 ();
+  printf ("before getcontext: tp2 = %p\n", p);
+  if (p != &blk)
+    FAIL_EXIT1 ("tpidr2 is not set to BLK %p", (void *)&blk);
+  r = getcontext (&ctx);
+  if (r != 0)
+    FAIL_EXIT1 ("getcontext failed");
+  if (setcontext_done == 0)
+    {
+      p = get_tpidr2 ();
+      printf ("before setcontext: tp2 = %p\n", p);
+      if (p != &blk)
+	FAIL_EXIT1 ("tpidr2 is clobbered");
+      setcontext_done = 1;
+      do_setcontext (&ctx);
+      FAIL_EXIT1 ("setcontext returned");
+    }
+  p = get_tpidr2 ();
+  printf ("after setcontext: tp2 = %p\n", p);
+  if (p != NULL)
+    FAIL_EXIT1 ("tpidr2 is not set to 0");
+  svcr = get_svcr ();
+  if (svcr != 0)
+    FAIL_EXIT1 ("svcr != 0: %lu", svcr);
+  print_data ("za save space", za_save);
+  r = memcmp (za_orig, za_save, svl*svl);
+  if (r != 0)
+    FAIL_EXIT1 ("saving za failed");
+}
+
+static int
+do_test (void)
+{
+  unsigned long hwcap2;
+
+  hwcap2 = getauxval (AT_HWCAP2);
+  if ((hwcap2 & HWCAP2_SME) == 0)
+    return EXIT_UNSUPPORTED;
+
+  svl = get_svl ();
+  printf ("svl: %lu\n", svl);
+  if (svl < 16 || svl % 16 != 0 || svl >= (1 << 16))
+    FAIL_EXIT1 ("invalid svl");
+
+  za_orig = xmalloc (svl*svl);
+  za_save = xmalloc (svl*svl);
+  za_dump = xmalloc (svl*svl);
+  memset (za_orig, 1, svl*svl);
+  memset (za_save, 2, svl*svl);
+  memset (za_dump, 3, svl*svl);
+  for (int i = 0; i < svl; i++)
+    for (int j = 0; j < svl; j++)
+      za_orig[i*svl+j] = i*svl+j;
+  print_data ("original data", za_orig);
+
+  longjmp_test ();
+
+  memset (za_save, 2, svl*svl);
+  memset (za_dump, 3, svl*svl);
+
+  setcontext_test ();
+
+  free (za_orig);
+  free (za_save);
+  free (za_dump);
+  return 0;
+}
+
+#include <support/test-driver.c>