From 9ce1263033cd2ad393e2ff0df4a1c4ab4992c9df Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Tue, 23 Jul 2019 19:58:52 +0200 Subject: selftests, arm64: add a selftest for passing tagged pointers to kernel 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. Reviewed-by: Catalin Marinas Acked-by: Kees Cook Signed-off-by: Andrey Konovalov Signed-off-by: Will Deacon --- tools/testing/selftests/arm64/.gitignore | 1 + tools/testing/selftests/arm64/Makefile | 11 ++++++++++ tools/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 (limited to 'tools/testing/selftests') 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 +#include +#include +#include +#include +#include + +#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; +} -- cgit v1.2.3-59-g8ed1b From 74585fcb7b3ccb35135e2418dd66251022a916e5 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Mon, 19 Aug 2019 15:14:42 +0200 Subject: selftests, arm64: fix uninitialized symbol in tags_test.c Fix tagged_ptr not being initialized when TBI is not enabled. Link: https://www.spinics.net/lists/linux-kselftest/msg09446.html Reported-by: Dan Carpenter Signed-off-by: Andrey Konovalov Signed-off-by: Will Deacon --- tools/testing/selftests/arm64/tags_test.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'tools/testing/selftests') diff --git a/tools/testing/selftests/arm64/tags_test.c b/tools/testing/selftests/arm64/tags_test.c index 22a1b266e373..5701163460ef 100644 --- a/tools/testing/selftests/arm64/tags_test.c +++ b/tools/testing/selftests/arm64/tags_test.c @@ -14,15 +14,17 @@ int main(void) { static int tbi_enabled = 0; - struct utsname *ptr, *tagged_ptr; + unsigned long tag = 0; + struct utsname *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); + tag = 0x42; + ptr = (struct utsname *)SET_TAG(ptr, tag); + err = uname(ptr); free(ptr); return err; -- cgit v1.2.3-59-g8ed1b