On Mon, Jun 24, 2019 at 04:33:00PM +0200, Andrey Konovalov wrote:
This patch is a part of a series that extends kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments.
This patch adds a simple test, that calls the uname syscall with a tagged user pointer as an argument. Without the kernel accepting tagged user pointers the test fails with EFAULT.
Signed-off-by: Andrey Konovalov andreyknvl@google.com
Acked-by: Kees Cook keescook@chromium.org
-Kees
tools/testing/selftests/arm64/.gitignore | 1 + tools/testing/selftests/arm64/Makefile | 11 +++++++ .../testing/selftests/arm64/run_tags_test.sh | 12 ++++++++ tools/testing/selftests/arm64/tags_test.c | 29 +++++++++++++++++++ 4 files changed, 53 insertions(+) create mode 100644 tools/testing/selftests/arm64/.gitignore create mode 100644 tools/testing/selftests/arm64/Makefile create mode 100755 tools/testing/selftests/arm64/run_tags_test.sh create mode 100644 tools/testing/selftests/arm64/tags_test.c
diff --git a/tools/testing/selftests/arm64/.gitignore b/tools/testing/selftests/arm64/.gitignore new file mode 100644 index 000000000000..e8fae8d61ed6 --- /dev/null +++ b/tools/testing/selftests/arm64/.gitignore @@ -0,0 +1 @@ +tags_test diff --git a/tools/testing/selftests/arm64/Makefile b/tools/testing/selftests/arm64/Makefile new file mode 100644 index 000000000000..a61b2e743e99 --- /dev/null +++ b/tools/testing/selftests/arm64/Makefile @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0
+# ARCH can be overridden by the user for cross compiling +ARCH ?= $(shell uname -m 2>/dev/null || echo not)
+ifneq (,$(filter $(ARCH),aarch64 arm64)) +TEST_GEN_PROGS := tags_test +TEST_PROGS := run_tags_test.sh +endif
+include ../lib.mk diff --git a/tools/testing/selftests/arm64/run_tags_test.sh b/tools/testing/selftests/arm64/run_tags_test.sh new file mode 100755 index 000000000000..745f11379930 --- /dev/null +++ b/tools/testing/selftests/arm64/run_tags_test.sh @@ -0,0 +1,12 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0
+echo "--------------------" +echo "running tags test" +echo "--------------------" +./tags_test +if [ $? -ne 0 ]; then
- echo "[FAIL]"
+else
- echo "[PASS]"
+fi diff --git a/tools/testing/selftests/arm64/tags_test.c b/tools/testing/selftests/arm64/tags_test.c new file mode 100644 index 000000000000..22a1b266e373 --- /dev/null +++ b/tools/testing/selftests/arm64/tags_test.c @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <stdint.h> +#include <sys/prctl.h> +#include <sys/utsname.h>
+#define SHIFT_TAG(tag) ((uint64_t)(tag) << 56) +#define SET_TAG(ptr, tag) (((uint64_t)(ptr) & ~SHIFT_TAG(0xff)) | \
SHIFT_TAG(tag))+int main(void) +{
- static int tbi_enabled = 0;
- struct utsname *ptr, *tagged_ptr;
- int err;
- if (prctl(PR_SET_TAGGED_ADDR_CTRL, PR_TAGGED_ADDR_ENABLE, 0, 0, 0) == 0)
tbi_enabled = 1;- ptr = (struct utsname *)malloc(sizeof(*ptr));
- if (tbi_enabled)
tagged_ptr = (struct utsname *)SET_TAG(ptr, 0x42);- err = uname(tagged_ptr);
- free(ptr);
- return err;
+}
2.22.0.410.gd8fdbe21b5-goog