On Mon, Jun 03, 2019 at 06:55:18PM +0200, Andrey Konovalov wrote:
This patch is a part of a series that extends arm64 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
I'm adding Shuah to CC in case she has some suggestions about the new selftest.
Reviewed-by: Kees Cook keescook@chromium.org
-Kees
tools/testing/selftests/arm64/.gitignore | 1 + tools/testing/selftests/arm64/Makefile | 22 ++++++++++ .../testing/selftests/arm64/run_tags_test.sh | 12 ++++++ tools/testing/selftests/arm64/tags_lib.c | 42 +++++++++++++++++++ tools/testing/selftests/arm64/tags_test.c | 18 ++++++++ 5 files changed, 95 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_lib.c 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..9dee18727923 --- /dev/null +++ b/tools/testing/selftests/arm64/Makefile @@ -0,0 +1,22 @@ +# SPDX-License-Identifier: GPL-2.0
+include ../lib.mk
+# 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_CUSTOM_PROGS := $(OUTPUT)/tags_test
+$(OUTPUT)/tags_test: tags_test.c $(OUTPUT)/tags_lib.so
- $(CC) -o $@ $(CFLAGS) $(LDFLAGS) $<
+$(OUTPUT)/tags_lib.so: tags_lib.c
- $(CC) -o $@ -shared $(CFLAGS) $(LDFLAGS) $^
+TEST_PROGS := run_tags_test.sh
+all: $(TEST_CUSTOM_PROGS)
+endif 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..2bbe0cd4220b --- /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 "--------------------" +LD_PRELOAD=./tags_lib.so ./tags_test +if [ $? -ne 0 ]; then
- echo "[FAIL]"
+else
- echo "[PASS]"
+fi diff --git a/tools/testing/selftests/arm64/tags_lib.c b/tools/testing/selftests/arm64/tags_lib.c new file mode 100644 index 000000000000..8a674509216e --- /dev/null +++ b/tools/testing/selftests/arm64/tags_lib.c @@ -0,0 +1,42 @@ +#include <stdlib.h>
+#define TAG_SHIFT (56) +#define TAG_MASK (0xffUL << TAG_SHIFT)
+void *__libc_malloc(size_t size); +void __libc_free(void *ptr); +void *__libc_realloc(void *ptr, size_t size); +void *__libc_calloc(size_t nmemb, size_t size);
+static void *tag_ptr(void *ptr) +{
- unsigned long tag = rand() & 0xff;
- if (!ptr)
return ptr;- return (void *)((unsigned long)ptr | (tag << TAG_SHIFT));
+}
+static void *untag_ptr(void *ptr) +{
- return (void *)((unsigned long)ptr & ~TAG_MASK);
+}
+void *malloc(size_t size) +{
- return tag_ptr(__libc_malloc(size));
+}
+void free(void *ptr) +{
- __libc_free(untag_ptr(ptr));
+}
+void *realloc(void *ptr, size_t size) +{
- return tag_ptr(__libc_realloc(untag_ptr(ptr), size));
+}
+void *calloc(size_t nmemb, size_t size) +{
- return tag_ptr(__libc_calloc(nmemb, size));
+} diff --git a/tools/testing/selftests/arm64/tags_test.c b/tools/testing/selftests/arm64/tags_test.c new file mode 100644 index 000000000000..263b302874ed --- /dev/null +++ b/tools/testing/selftests/arm64/tags_test.c @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <stdint.h> +#include <sys/utsname.h>
+int main(void) +{
- struct utsname *ptr;
- int err;
- ptr = (struct utsname *)malloc(sizeof(*ptr));
- err = uname(ptr);
- free(ptr);
- return err;
+}
2.22.0.rc1.311.g5d7573a151-goog