[PATCH v4 3/3] aarch64: Add tests for glibc.cpu.aarch64_bti behaviour

Yury Khrustalev yury.khrustalev@arm.com
Mon Dec 1 16:14:58 GMT 2025


Check that the new tunable changes behaviour correctly:

 * When BTI is enforced, any unmarked binary that is loaded
   results in an error: either an abort or dlopen error when
   this binary is loaded via dlopen.
 * When BTI is not enforced, it is OK to load an unmarked
   binary.
---
 sysdeps/aarch64/Makefile                      | 57 ++++++++++++++++-
 sysdeps/aarch64/tst-bti-abort-imm.c           |  3 +
 sysdeps/aarch64/tst-bti-abort-transitive.c    |  3 +
 sysdeps/aarch64/tst-bti-abort-unprot.c        |  3 +
 sysdeps/aarch64/tst-bti-abort.sh              | 39 ++++++++++++
 sysdeps/aarch64/tst-bti-dep-prot.c            |  3 +
 sysdeps/aarch64/tst-bti-dlopen-imm.c          |  6 ++
 sysdeps/aarch64/tst-bti-dlopen-prot.c         |  6 ++
 sysdeps/aarch64/tst-bti-dlopen-transitive.c   |  6 ++
 sysdeps/aarch64/tst-bti-mod-prot.c            | 30 +++++++++
 sysdeps/aarch64/tst-bti-mod-unprot.c          | 30 +++++++++
 sysdeps/aarch64/tst-bti-mod.c                 | 27 ++++++++
 sysdeps/aarch64/tst-bti-permissive-dlopen.c   |  6 ++
 sysdeps/aarch64/tst-bti-permissive-imm.c      |  3 +
 .../aarch64/tst-bti-permissive-transitive.c   |  3 +
 sysdeps/aarch64/tst-bti-skeleton-dlopen.c     | 62 +++++++++++++++++++
 sysdeps/aarch64/tst-bti-skeleton.c            | 45 ++++++++++++++
 17 files changed, 331 insertions(+), 1 deletion(-)
 create mode 100644 sysdeps/aarch64/tst-bti-abort-imm.c
 create mode 100644 sysdeps/aarch64/tst-bti-abort-transitive.c
 create mode 100644 sysdeps/aarch64/tst-bti-abort-unprot.c
 create mode 100644 sysdeps/aarch64/tst-bti-abort.sh
 create mode 100644 sysdeps/aarch64/tst-bti-dep-prot.c
 create mode 100644 sysdeps/aarch64/tst-bti-dlopen-imm.c
 create mode 100644 sysdeps/aarch64/tst-bti-dlopen-prot.c
 create mode 100644 sysdeps/aarch64/tst-bti-dlopen-transitive.c
 create mode 100644 sysdeps/aarch64/tst-bti-mod-prot.c
 create mode 100644 sysdeps/aarch64/tst-bti-mod-unprot.c
 create mode 100644 sysdeps/aarch64/tst-bti-mod.c
 create mode 100644 sysdeps/aarch64/tst-bti-permissive-dlopen.c
 create mode 100644 sysdeps/aarch64/tst-bti-permissive-imm.c
 create mode 100644 sysdeps/aarch64/tst-bti-permissive-transitive.c
 create mode 100644 sysdeps/aarch64/tst-bti-skeleton-dlopen.c
 create mode 100644 sysdeps/aarch64/tst-bti-skeleton.c

diff --git a/sysdeps/aarch64/Makefile b/sysdeps/aarch64/Makefile
index 29348912e3..d8defadafa 100644
--- a/sysdeps/aarch64/Makefile
+++ b/sysdeps/aarch64/Makefile
@@ -83,8 +83,63 @@ tests-internal += \
 
 $(objpfx)tst-sme-clone3: $(objpfx)clone3.o $(objpfx)__arm_za_disable.o
 
+ifeq (yes,$(have-test-bti))
+
+tests += \
+  tst-bti-abort-imm \
+  tst-bti-abort-transitive \
+  tst-bti-abort-unprot \
+  tst-bti-dep-prot \
+  tst-bti-dlopen-imm \
+  tst-bti-dlopen-prot \
+  tst-bti-dlopen-transitive \
+  tst-bti-permissive-dlopen \
+  tst-bti-permissive-imm \
+  tst-bti-permissive-transitive \
+  # tests
+
+modules-names += \
+  tst-bti-mod \
+  tst-bti-mod-prot \
+  tst-bti-mod-unprot
+
+$(objpfx)tst-bti-abort-imm: $(objpfx)tst-bti-mod-unprot.so
+$(objpfx)tst-bti-abort-transitive: $(objpfx)tst-bti-mod.so
+$(objpfx)tst-bti-abort-unprot: $(objpfx)tst-bti-mod-prot.so
+$(objpfx)tst-bti-dep-prot: $(objpfx)tst-bti-mod-prot.so
+$(objpfx)tst-bti-mod.so: $(objpfx)tst-bti-mod-unprot.so
+$(objpfx)tst-bti-permissive-imm: $(objpfx)tst-bti-mod-unprot.so
+$(objpfx)tst-bti-permissive-transitive: $(objpfx)tst-bti-mod.so
+
+CFLAGS-tst-bti-abort-unprot.o += -mbranch-protection=none
+CFLAGS-tst-bti-mod-unprot.os += -mbranch-protection=none
+
+tst-bti-abort-imm-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_bti=1
+tst-bti-abort-transitive-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_bti=1
+tst-bti-abort-unprot-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_bti=1
+tst-bti-dep-prot-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_bti=1
+tst-bti-dlopen-imm-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_bti=1
+tst-bti-dlopen-prot-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_bti=1
+tst-bti-dlopen-transitive-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_bti=1
+
+tst-bti-permissive-imm-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_bti=0
+tst-bti-permissive-transitive-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_bti=0
+tst-bti-permissive-dlopen-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_bti=0
+
+define run-bti-abort-test
+  $(test-wrapper-env) $(run-program-env) \
+  $(tst-bti-abort-$*-ENV) $(host-test-program-cmd)
+endef
+
+$(objpfx)tst-bti-abort-%.out: $(..)sysdeps/aarch64/tst-bti-abort.sh \
+	$(objpfx)tst-bti-abort-%
+	$(SHELL) $< $(common-objpfx) $(test-name) '$(run-bti-abort-test)'; \
+	$(evaluate-test)
+
+endif # ifeq (yes,$(have-test-bti))
+
 endif
 
 ifeq ($(subdir),malloc)
 sysdep_malloc_debug_routines = __mtag_tag_zero_region __mtag_tag_region
-endif
+endif # malloc directory
diff --git a/sysdeps/aarch64/tst-bti-abort-imm.c b/sysdeps/aarch64/tst-bti-abort-imm.c
new file mode 100644
index 0000000000..60d29f6773
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-abort-imm.c
@@ -0,0 +1,3 @@
+/* This test checks that process is aborted when an immediate
+   dependency is not marked with BTI and BTI is enforced.  */
+#include "tst-bti-skeleton.c"
diff --git a/sysdeps/aarch64/tst-bti-abort-transitive.c b/sysdeps/aarch64/tst-bti-abort-transitive.c
new file mode 100644
index 0000000000..1264ae0362
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-abort-transitive.c
@@ -0,0 +1,3 @@
+/* This test checks that process is aborted when a transitive
+   dependency is not marked with BTI and BTI is enforced.  */
+#include "tst-bti-skeleton.c"
diff --git a/sysdeps/aarch64/tst-bti-abort-unprot.c b/sysdeps/aarch64/tst-bti-abort-unprot.c
new file mode 100644
index 0000000000..6c3b31b421
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-abort-unprot.c
@@ -0,0 +1,3 @@
+/* This test checks that process is aborted the executable
+   is not marked with BTI and BTI is enforced.  */
+#include "tst-bti-skeleton.c"
diff --git a/sysdeps/aarch64/tst-bti-abort.sh b/sysdeps/aarch64/tst-bti-abort.sh
new file mode 100644
index 0000000000..d2ef007be4
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-abort.sh
@@ -0,0 +1,39 @@
+#!/bin/sh
+# Test wrapper for AArch64 tests for BTI that are expected to abort.
+# 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/>.
+
+objpfx=$1; shift
+tstname=$1; shift
+tstrun=$1; shift
+
+logfile=$objpfx/$tstname.out
+
+rm -vf $logfile
+touch $logfile
+
+${tstrun} 2>> $logfile >> $logfile; status=$?
+
+if test $status -eq 127 \
+  && grep -q -w "failed to turn on BTI protection" "$logfile" ; then
+  exit 0
+elif test $status -eq 77; then
+  exit 77
+else
+  echo "expected 'failed to turn on BTI protection' not $status return status"
+  exit 1
+fi
diff --git a/sysdeps/aarch64/tst-bti-dep-prot.c b/sysdeps/aarch64/tst-bti-dep-prot.c
new file mode 100644
index 0000000000..9da00a68bd
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-dep-prot.c
@@ -0,0 +1,3 @@
+/* This test checks that program works correctly when an immediate
+   dependency is marked with BTI and BTI is enforced.  */
+#include "tst-bti-skeleton.c"
diff --git a/sysdeps/aarch64/tst-bti-dlopen-imm.c b/sysdeps/aarch64/tst-bti-dlopen-imm.c
new file mode 100644
index 0000000000..262bb70abe
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-dlopen-imm.c
@@ -0,0 +1,6 @@
+/* This test checks that dlopen returns an error when a dependency
+   is loaded via dlopen and the corresponding binary is not marked
+   with BTI while BTI is enforced.  */
+#define TEST_BTI_DLOPEN_MODULE "tst-bti-mod-unprot.so"
+#define TEST_BTI_EXPECT_DLOPEN 0
+#include "tst-bti-skeleton-dlopen.c"
diff --git a/sysdeps/aarch64/tst-bti-dlopen-prot.c b/sysdeps/aarch64/tst-bti-dlopen-prot.c
new file mode 100644
index 0000000000..10e4fb79ce
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-dlopen-prot.c
@@ -0,0 +1,6 @@
+/* This test checks that dlopen succeeds when a dependency is loaded
+   via dlopen and the corresponding binary is marked with BTI
+   while BTI is enforced.  */
+#define TEST_BTI_DLOPEN_MODULE "tst-bti-mod-prot.so"
+#define TEST_BTI_EXPECT_DLOPEN 1
+#include "tst-bti-skeleton-dlopen.c"
diff --git a/sysdeps/aarch64/tst-bti-dlopen-transitive.c b/sysdeps/aarch64/tst-bti-dlopen-transitive.c
new file mode 100644
index 0000000000..4f4f8456cc
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-dlopen-transitive.c
@@ -0,0 +1,6 @@
+/* This test checks that dlopen returns an error when a dependency
+   is loaded via dlopen that has an unmarked dependency while BTI
+   is enforced.  */
+#define TEST_BTI_DLOPEN_MODULE "tst-bti-mod.so"
+#define TEST_BTI_EXPECT_DLOPEN 0
+#include "tst-bti-skeleton-dlopen.c"
diff --git a/sysdeps/aarch64/tst-bti-mod-prot.c b/sysdeps/aarch64/tst-bti-mod-prot.c
new file mode 100644
index 0000000000..1187e0f8c9
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-mod-prot.c
@@ -0,0 +1,30 @@
+/* This SO will be linked with BTI marking.
+   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>
+
+int foo (void)
+{
+  puts ("called function fun unprot");
+  return 0;
+}
+
+int fun (void)
+{
+  return 0;
+}
diff --git a/sysdeps/aarch64/tst-bti-mod-unprot.c b/sysdeps/aarch64/tst-bti-mod-unprot.c
new file mode 100644
index 0000000000..03b656d2dd
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-mod-unprot.c
@@ -0,0 +1,30 @@
+/* This SO will be linked without BTI marking.
+   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>
+
+int foo (void)
+{
+  puts ("called function fun unprot");
+  return 0;
+}
+
+int fun (void)
+{
+  return 0;
+}
diff --git a/sysdeps/aarch64/tst-bti-mod.c b/sysdeps/aarch64/tst-bti-mod.c
new file mode 100644
index 0000000000..79b48d2561
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-mod.c
@@ -0,0 +1,27 @@
+/* DSO for testing BTI.
+   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>
+
+extern int foo (void);
+
+int fun (void)
+{
+  puts ("called function fun");
+  return foo ();
+}
diff --git a/sysdeps/aarch64/tst-bti-permissive-dlopen.c b/sysdeps/aarch64/tst-bti-permissive-dlopen.c
new file mode 100644
index 0000000000..bcfa1601ed
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-permissive-dlopen.c
@@ -0,0 +1,6 @@
+/* This test checks that dlopen succeeds when a dependency is loaded
+   via dlopen and the corresponding binary is not marked with BTI
+   while BTI is not enforced.  */
+#define TEST_BTI_DLOPEN_MODULE "tst-bti-mod-unprot.so"
+#define TEST_BTI_EXPECT_DLOPEN 1
+#include "tst-bti-skeleton-dlopen.c"
diff --git a/sysdeps/aarch64/tst-bti-permissive-imm.c b/sysdeps/aarch64/tst-bti-permissive-imm.c
new file mode 100644
index 0000000000..61a993d3b0
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-permissive-imm.c
@@ -0,0 +1,3 @@
+/* This test checks that process runs when an immediate
+   dependency is not marked with BTI but BTI is not enforced.  */
+#include "tst-bti-skeleton.c"
diff --git a/sysdeps/aarch64/tst-bti-permissive-transitive.c b/sysdeps/aarch64/tst-bti-permissive-transitive.c
new file mode 100644
index 0000000000..0808fe17f6
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-permissive-transitive.c
@@ -0,0 +1,3 @@
+/* This test checks that process runs when a transitive
+   dependency is not marked with BTI but BTI is not enforced.  */
+#include "tst-bti-skeleton.c"
diff --git a/sysdeps/aarch64/tst-bti-skeleton-dlopen.c b/sysdeps/aarch64/tst-bti-skeleton-dlopen.c
new file mode 100644
index 0000000000..b855b9a7d4
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-skeleton-dlopen.c
@@ -0,0 +1,62 @@
+/* Simple test for BTI support with dlopen: this base source file is
+   included in several 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/>.  */
+
+#include <stdio.h>
+#include <dlfcn.h>
+#include <string.h>
+#include <sys/auxv.h>
+#include <sys/signal.h>
+
+#include <support/check.h>
+#include <support/test-driver.h>
+
+typedef int (*fun_t) (void);
+
+static int
+do_test (void)
+{
+  unsigned long hwcap2 = getauxval (AT_HWCAP2);
+  if ((hwcap2 & HWCAP2_BTI) == 0)
+    {
+      FAIL_UNSUPPORTED ("BTI is not supported by this system");
+    }
+
+  void *h = dlopen (TEST_BTI_DLOPEN_MODULE, RTLD_NOW);
+  const char *err = dlerror ();
+
+#if TEST_BTI_EXPECT_DLOPEN
+  TEST_VERIFY (h != NULL);
+#else
+  TEST_VERIFY (h == NULL);
+  /* Only accept expected BTI-related errors.  */
+  TEST_VERIFY (strstr (err, "failed to turn on BTI protection") != NULL);
+#endif
+
+  if (h == NULL)
+    printf ("dlopen error: %s\n", err);
+  else
+    {
+      puts ("library "  TEST_BTI_DLOPEN_MODULE " loaded normally");
+      dlclose (h);
+    }
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/aarch64/tst-bti-skeleton.c b/sysdeps/aarch64/tst-bti-skeleton.c
new file mode 100644
index 0000000000..460b4302c9
--- /dev/null
+++ b/sysdeps/aarch64/tst-bti-skeleton.c
@@ -0,0 +1,45 @@
+/* Simple test for BTI support: this base source file is included in
+   several 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/>.  */
+
+#include <stdio.h>
+#include <sys/auxv.h>
+#include <sys/signal.h>
+
+#include <support/check.h>
+#include <support/test-driver.h>
+
+/* Defined in tst-bti-mod.c file.  */
+extern int fun (void);
+
+typedef int (*fun_t) (void);
+
+static int
+do_test (void)
+{
+  unsigned long hwcap2 = getauxval (AT_HWCAP2);
+  if ((hwcap2 & HWCAP2_BTI) == 0)
+    {
+      FAIL_UNSUPPORTED ("BTI is not supported by this system");
+    }
+
+  fun_t fn = &fun;
+  return fn ();
+}
+
+#include <support/test-driver.c>
-- 
2.47.3



More information about the Libc-alpha mailing list