[1/4] aarch64: Add tests for Guarded Control Stack
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| linaro-tcwg-bot/tcwg_glibc_build--master-arm |
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| linaro-tcwg-bot/tcwg_glibc_check--master-arm |
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| linaro-tcwg-bot/tcwg_glibc_build--master-aarch64 |
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Commit Message
These tests validate that GCS tunable works as expected depending
on the GCS markings in the test binaries.
Tests validate both static and dynamically linked binaries.
Test will build and run on AArch64 targets only and if GCS is not
enabled on the platform running tests, they will be reported as
UNSUPPORTED.
When linking tests a new linker command line flag -z gcs=<value>
is used. If the toolchain used to build these tests doesn't support
this flag, there will be a warning that is expected and should be
ignored.
---
sysdeps/unix/sysv/linux/aarch64/Makefile | 64 +++++++++++++++++++
.../unix/sysv/linux/aarch64/tst-gcs-abort.sh | 40 ++++++++++++
.../linux/aarch64/tst-gcs-disabled-static.c | 1 +
.../sysv/linux/aarch64/tst-gcs-disabled.c | 2 +
.../linux/aarch64/tst-gcs-enforced-abort.c | 2 +
.../aarch64/tst-gcs-enforced-static-abort.c | 1 +
.../linux/aarch64/tst-gcs-enforced-static.c | 1 +
.../sysv/linux/aarch64/tst-gcs-enforced.c | 2 +
.../sysv/linux/aarch64/tst-gcs-optional-off.c | 2 +
.../sysv/linux/aarch64/tst-gcs-optional-on.c | 2 +
.../aarch64/tst-gcs-optional-static-off.c | 1 +
.../aarch64/tst-gcs-optional-static-on.c | 1 +
.../linux/aarch64/tst-gcs-override-static.c | 1 +
.../sysv/linux/aarch64/tst-gcs-override.c | 2 +
.../sysv/linux/aarch64/tst-gcs-skeleton.c | 58 +++++++++++++++++
15 files changed, 180 insertions(+)
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled-static.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-abort.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static-abort.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-off.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-on.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-off.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-on.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-override-static.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-override.c
create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-skeleton.c
Comments
On 23/01/25 11:13, Yury Khrustalev wrote:
> These tests validate that GCS tunable works as expected depending
> on the GCS markings in the test binaries.
>
> Tests validate both static and dynamically linked binaries.
>
> Test will build and run on AArch64 targets only and if GCS is not
> enabled on the platform running tests, they will be reported as
> UNSUPPORTED.
>
> When linking tests a new linker command line flag -z gcs=<value>
> is used. If the toolchain used to build these tests doesn't support
> this flag, there will be a warning that is expected and should be
> ignored.
I think it would be better to add a configure check for '-z gcs=' support
and do not enable them if linker does not support it.
Making them UNSUPPORTED might be somewhat misleading without also check the
build outout for '-z gcs=always ignored', because on systems with HWCAP_GCS
it will result in some unexpect results for __check_gcs_status.
> ---
> sysdeps/unix/sysv/linux/aarch64/Makefile | 64 +++++++++++++++++++
> .../unix/sysv/linux/aarch64/tst-gcs-abort.sh | 40 ++++++++++++
> .../linux/aarch64/tst-gcs-disabled-static.c | 1 +
> .../sysv/linux/aarch64/tst-gcs-disabled.c | 2 +
> .../linux/aarch64/tst-gcs-enforced-abort.c | 2 +
> .../aarch64/tst-gcs-enforced-static-abort.c | 1 +
> .../linux/aarch64/tst-gcs-enforced-static.c | 1 +
> .../sysv/linux/aarch64/tst-gcs-enforced.c | 2 +
> .../sysv/linux/aarch64/tst-gcs-optional-off.c | 2 +
> .../sysv/linux/aarch64/tst-gcs-optional-on.c | 2 +
> .../aarch64/tst-gcs-optional-static-off.c | 1 +
> .../aarch64/tst-gcs-optional-static-on.c | 1 +
> .../linux/aarch64/tst-gcs-override-static.c | 1 +
> .../sysv/linux/aarch64/tst-gcs-override.c | 2 +
> .../sysv/linux/aarch64/tst-gcs-skeleton.c | 58 +++++++++++++++++
> 15 files changed, 180 insertions(+)
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled-static.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-abort.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static-abort.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-off.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-on.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-off.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-on.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-override-static.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-override.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-skeleton.c
>
> diff --git a/sysdeps/unix/sysv/linux/aarch64/Makefile b/sysdeps/unix/sysv/linux/aarch64/Makefile
> index 1fdad67fae..82a992bc14 100644
> --- a/sysdeps/unix/sysv/linux/aarch64/Makefile
> +++ b/sysdeps/unix/sysv/linux/aarch64/Makefile
> @@ -1,8 +1,72 @@
> ifeq ($(subdir),misc)
> sysdep_headers += sys/elf.h
> +
> +gcs-tests-dynamic = \
> + tst-gcs-disabled \
> + tst-gcs-enforced \
> + tst-gcs-enforced-abort \
> + tst-gcs-optional-off \
> + tst-gcs-optional-on \
> + tst-gcs-override \
> + # gcs-tests-dynamic
> +
> +gcs-tests-static = \
> + tst-gcs-disabled-static \
> + tst-gcs-enforced-static \
> + tst-gcs-enforced-static-abort \
> + tst-gcs-optional-static-off \
> + tst-gcs-optional-static-on \
> + tst-gcs-override-static \
> + # gcs-tests-static
> +
> tests += \
> + $(gcs-tests-dynamic) \
> + $(gcs-tests-static) \
> tst-aarch64-pkey \
> # tests
> +
> +tests-static += \
> + $(gcs-tests-static) \
> + # tests-static
> +
> +define run-gcs-abort-test
> + $(test-wrapper-env) $(run-program-env) \
> + $(tst-gcs-$*-abort-ENV) $(host-test-program-cmd)
> +endef
> +
> +$(objpfx)tst-gcs-%-abort.out: $(..)sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh \
> + $(objpfx)tst-gcs-%-abort
> + $(SHELL) $< $(common-objpfx) $(test-name) '$(run-gcs-abort-test)'; \
> + $(evaluate-test)
> +
> +LDFLAGS-tst-gcs-disabled += -Wl,-z gcs=always
> +LDFLAGS-tst-gcs-enforced += -Wl,-z gcs=always
> +LDFLAGS-tst-gcs-enforced-abort += -Wl,-z gcs=never
> +LDFLAGS-tst-gcs-optional-on += -Wl,-z gcs=always
> +LDFLAGS-tst-gcs-optional-off += -Wl,-z gcs=never
> +LDFLAGS-tst-gcs-override += -Wl,-z gcs=never
> +
> +LDFLAGS-tst-gcs-disabled-static += -Wl,-z gcs=always
> +LDFLAGS-tst-gcs-enforced-static += -Wl,-z gcs=always
> +LDFLAGS-tst-gcs-enforced-static-abort += -Wl,-z gcs=never
> +LDFLAGS-tst-gcs-optional-static-on += -Wl,-z gcs=always
> +LDFLAGS-tst-gcs-optional-static-off += -Wl,-z gcs=never
> +LDFLAGS-tst-gcs-override-static += -Wl,-z gcs=never
> +
> +tst-gcs-disabled-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=0
> +tst-gcs-enforced-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
> +tst-gcs-enforced-abort-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
> +tst-gcs-optional-on-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
> +tst-gcs-optional-off-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
> +tst-gcs-override-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=3
> +
> +tst-gcs-disabled-static-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=0
> +tst-gcs-enforced-static-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
> +tst-gcs-enforced-static-abort-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
> +tst-gcs-optional-static-on-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
> +tst-gcs-optional-static-off-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
> +tst-gcs-override-static-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=3
> +
> endif
>
> ifeq ($(subdir),stdlib)
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh
> new file mode 100644
> index 0000000000..5c1889bfcd
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh
> @@ -0,0 +1,40 @@
> +#!/bin/sh
> +# Test wrapper for AArch64 tests for GCS that are expected to abort.
> +# Copyright (C) 2001-2025 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 $status -eq 127 \
> + && grep -q -w "not GCS compatible" "$logfile" ; then
> + exit 0
> +elif test $status -eq 77; then
> + exit 77
> +else
> + echo "unexpected test output or exit status $status"
> + exit 1
> +fi
> +
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled-static.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled-static.c
> new file mode 100644
> index 0000000000..c71d68cb86
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled-static.c
> @@ -0,0 +1 @@
> +#include "tst-gcs-disabled.c"
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled.c
> new file mode 100644
> index 0000000000..bd688785bb
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled.c
> @@ -0,0 +1,2 @@
> +#define TEST_GCS_EXPECT_ENABLED 0
> +#include "tst-gcs-skeleton.c"
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-abort.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-abort.c
> new file mode 100644
> index 0000000000..608318f26d
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-abort.c
> @@ -0,0 +1,2 @@
> +#define TEST_GCS_EXPECT_ENABLED 1
> +#include "tst-gcs-skeleton.c"
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static-abort.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static-abort.c
> new file mode 100644
> index 0000000000..c20a999f6b
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static-abort.c
> @@ -0,0 +1 @@
> +#include "tst-gcs-enforced-abort.c"
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static.c
> new file mode 100644
> index 0000000000..bb39dada55
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static.c
> @@ -0,0 +1 @@
> +#include "tst-gcs-enforced.c"
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced.c
> new file mode 100644
> index 0000000000..608318f26d
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced.c
> @@ -0,0 +1,2 @@
> +#define TEST_GCS_EXPECT_ENABLED 1
> +#include "tst-gcs-skeleton.c"
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-off.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-off.c
> new file mode 100644
> index 0000000000..bd688785bb
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-off.c
> @@ -0,0 +1,2 @@
> +#define TEST_GCS_EXPECT_ENABLED 0
> +#include "tst-gcs-skeleton.c"
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-on.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-on.c
> new file mode 100644
> index 0000000000..608318f26d
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-on.c
> @@ -0,0 +1,2 @@
> +#define TEST_GCS_EXPECT_ENABLED 1
> +#include "tst-gcs-skeleton.c"
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-off.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-off.c
> new file mode 100644
> index 0000000000..54e3b9a0d5
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-off.c
> @@ -0,0 +1 @@
> +#include "tst-gcs-optional-off.c"
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-on.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-on.c
> new file mode 100644
> index 0000000000..11b884b429
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-on.c
> @@ -0,0 +1 @@
> +#include "tst-gcs-optional-on.c"
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override-static.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override-static.c
> new file mode 100644
> index 0000000000..09055dcdc4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override-static.c
> @@ -0,0 +1 @@
> +#include "tst-gcs-override.c"
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override.c
> new file mode 100644
> index 0000000000..608318f26d
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override.c
> @@ -0,0 +1,2 @@
> +#define TEST_GCS_EXPECT_ENABLED 1
> +#include "tst-gcs-skeleton.c"
> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-skeleton.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-skeleton.c
> new file mode 100644
> index 0000000000..37692c96d0
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-skeleton.c
> @@ -0,0 +1,58 @@
> +/* AArch64 tests for GCS.
> + 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 <support/check.h>
> +#include <support/support.h>
> +#include <support/test-driver.h>
> +
> +#include <stdio.h>
> +#include <sys/auxv.h>
> +
> +static bool __check_gcs_status (void)
> +{
> + register unsigned long x16 asm ("x16");
> + asm volatile (
> + "mov x16, #1 /* _CHKFEAT_GCS */\n"
> + "hint 40 /* CHKFEAT_X16 */\n"
> + : "=r" (x16));
> + return x16 ^ 1;
> +}
> +
> +static int
> +do_test (void)
> +{
> + /* Check if GCS could possible by enabled. */
> + if (!(getauxval (AT_HWCAP) & HWCAP_GCS))
> + {
> + puts ("kernel or CPU does not support GCS");
> + return EXIT_UNSUPPORTED;
> + }
> + bool gcs_enabled = __check_gcs_status ();
> + if (gcs_enabled)
> + puts ("GCS enabled");
> + else
> + puts ("GCS not enabled");
> +#if TEST_GCS_EXPECT_ENABLED
> + TEST_VERIFY (gcs_enabled);
> +#else
> + TEST_VERIFY (!gcs_enabled);
> +#endif
> + return 0;
> +}
> +
> +#include <support/test-driver.c>
The rest looks ok.
On Mon, Jan 27, 2025 at 05:47:21PM -0300, Adhemerval Zanella Netto wrote:
>
> On 23/01/25 11:13, Yury Khrustalev wrote:
> > These tests validate that GCS tunable works as expected depending
> > on the GCS markings in the test binaries.
> >
> > Tests validate both static and dynamically linked binaries.
> >
> > Test will build and run on AArch64 targets only and if GCS is not
> > enabled on the platform running tests, they will be reported as
> > UNSUPPORTED.
> >
> > When linking tests a new linker command line flag -z gcs=<value>
> > is used. If the toolchain used to build these tests doesn't support
> > this flag, there will be a warning that is expected and should be
> > ignored.
>
> I think it would be better to add a configure check for '-z gcs=' support
> and do not enable them if linker does not support it.
Such an option would only be needed for tests however it may give an
impression that it can be used for the library code as well which would
be incorrect. I'm not sure what is the best approach here but it would
be good to use some sort of test-only configuration.
> Making them UNSUPPORTED might be somewhat misleading without also check the
> build outout for '-z gcs=always ignored', because on systems with HWCAP_GCS
> it will result in some unexpect results for __check_gcs_status.
This is true, some of the tests will fail on such a system. I'm using assumption
that the toolchain supports GCS if we intend to run tests on a system that has
HWCAP_GCS.
Please note that there is v2 of this series:
https://inbox.sourceware.org/libc-alpha/20250124122858.3788655-1-yury.khrustalev@arm.com/
> > ---
> > sysdeps/unix/sysv/linux/aarch64/Makefile | 64 +++++++++++++++++++
> > .../unix/sysv/linux/aarch64/tst-gcs-abort.sh | 40 ++++++++++++
> > .../linux/aarch64/tst-gcs-disabled-static.c | 1 +
> > .../sysv/linux/aarch64/tst-gcs-disabled.c | 2 +
> > .../linux/aarch64/tst-gcs-enforced-abort.c | 2 +
> > .../aarch64/tst-gcs-enforced-static-abort.c | 1 +
> > .../linux/aarch64/tst-gcs-enforced-static.c | 1 +
> > .../sysv/linux/aarch64/tst-gcs-enforced.c | 2 +
> > .../sysv/linux/aarch64/tst-gcs-optional-off.c | 2 +
> > .../sysv/linux/aarch64/tst-gcs-optional-on.c | 2 +
> > .../aarch64/tst-gcs-optional-static-off.c | 1 +
> > .../aarch64/tst-gcs-optional-static-on.c | 1 +
> > .../linux/aarch64/tst-gcs-override-static.c | 1 +
> > .../sysv/linux/aarch64/tst-gcs-override.c | 2 +
> > .../sysv/linux/aarch64/tst-gcs-skeleton.c | 58 +++++++++++++++++
> > 15 files changed, 180 insertions(+)
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled-static.c
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled.c
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-abort.c
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static-abort.c
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static.c
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced.c
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-off.c
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-on.c
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-off.c
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-on.c
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-override-static.c
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-override.c
> > create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-skeleton.c
> >
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/Makefile b/sysdeps/unix/sysv/linux/aarch64/Makefile
> > index 1fdad67fae..82a992bc14 100644
> > --- a/sysdeps/unix/sysv/linux/aarch64/Makefile
> > +++ b/sysdeps/unix/sysv/linux/aarch64/Makefile
> > @@ -1,8 +1,72 @@
> > ifeq ($(subdir),misc)
> > sysdep_headers += sys/elf.h
> > +
> > +gcs-tests-dynamic = \
> > + tst-gcs-disabled \
> > + tst-gcs-enforced \
> > + tst-gcs-enforced-abort \
> > + tst-gcs-optional-off \
> > + tst-gcs-optional-on \
> > + tst-gcs-override \
> > + # gcs-tests-dynamic
> > +
> > +gcs-tests-static = \
> > + tst-gcs-disabled-static \
> > + tst-gcs-enforced-static \
> > + tst-gcs-enforced-static-abort \
> > + tst-gcs-optional-static-off \
> > + tst-gcs-optional-static-on \
> > + tst-gcs-override-static \
> > + # gcs-tests-static
> > +
> > tests += \
> > + $(gcs-tests-dynamic) \
> > + $(gcs-tests-static) \
> > tst-aarch64-pkey \
> > # tests
> > +
> > +tests-static += \
> > + $(gcs-tests-static) \
> > + # tests-static
> > +
> > +define run-gcs-abort-test
> > + $(test-wrapper-env) $(run-program-env) \
> > + $(tst-gcs-$*-abort-ENV) $(host-test-program-cmd)
> > +endef
> > +
> > +$(objpfx)tst-gcs-%-abort.out: $(..)sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh \
> > + $(objpfx)tst-gcs-%-abort
> > + $(SHELL) $< $(common-objpfx) $(test-name) '$(run-gcs-abort-test)'; \
> > + $(evaluate-test)
> > +
> > +LDFLAGS-tst-gcs-disabled += -Wl,-z gcs=always
> > +LDFLAGS-tst-gcs-enforced += -Wl,-z gcs=always
> > +LDFLAGS-tst-gcs-enforced-abort += -Wl,-z gcs=never
> > +LDFLAGS-tst-gcs-optional-on += -Wl,-z gcs=always
> > +LDFLAGS-tst-gcs-optional-off += -Wl,-z gcs=never
> > +LDFLAGS-tst-gcs-override += -Wl,-z gcs=never
> > +
> > +LDFLAGS-tst-gcs-disabled-static += -Wl,-z gcs=always
> > +LDFLAGS-tst-gcs-enforced-static += -Wl,-z gcs=always
> > +LDFLAGS-tst-gcs-enforced-static-abort += -Wl,-z gcs=never
> > +LDFLAGS-tst-gcs-optional-static-on += -Wl,-z gcs=always
> > +LDFLAGS-tst-gcs-optional-static-off += -Wl,-z gcs=never
> > +LDFLAGS-tst-gcs-override-static += -Wl,-z gcs=never
> > +
> > +tst-gcs-disabled-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=0
> > +tst-gcs-enforced-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
> > +tst-gcs-enforced-abort-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
> > +tst-gcs-optional-on-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
> > +tst-gcs-optional-off-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
> > +tst-gcs-override-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=3
> > +
> > +tst-gcs-disabled-static-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=0
> > +tst-gcs-enforced-static-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
> > +tst-gcs-enforced-static-abort-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
> > +tst-gcs-optional-static-on-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
> > +tst-gcs-optional-static-off-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
> > +tst-gcs-override-static-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=3
> > +
> > endif
> >
> > ifeq ($(subdir),stdlib)
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh
> > new file mode 100644
> > index 0000000000..5c1889bfcd
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh
> > @@ -0,0 +1,40 @@
> > +#!/bin/sh
> > +# Test wrapper for AArch64 tests for GCS that are expected to abort.
> > +# Copyright (C) 2001-2025 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 $status -eq 127 \
> > + && grep -q -w "not GCS compatible" "$logfile" ; then
> > + exit 0
> > +elif test $status -eq 77; then
> > + exit 77
> > +else
> > + echo "unexpected test output or exit status $status"
> > + exit 1
> > +fi
> > +
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled-static.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled-static.c
> > new file mode 100644
> > index 0000000000..c71d68cb86
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled-static.c
> > @@ -0,0 +1 @@
> > +#include "tst-gcs-disabled.c"
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled.c
> > new file mode 100644
> > index 0000000000..bd688785bb
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled.c
> > @@ -0,0 +1,2 @@
> > +#define TEST_GCS_EXPECT_ENABLED 0
> > +#include "tst-gcs-skeleton.c"
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-abort.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-abort.c
> > new file mode 100644
> > index 0000000000..608318f26d
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-abort.c
> > @@ -0,0 +1,2 @@
> > +#define TEST_GCS_EXPECT_ENABLED 1
> > +#include "tst-gcs-skeleton.c"
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static-abort.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static-abort.c
> > new file mode 100644
> > index 0000000000..c20a999f6b
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static-abort.c
> > @@ -0,0 +1 @@
> > +#include "tst-gcs-enforced-abort.c"
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static.c
> > new file mode 100644
> > index 0000000000..bb39dada55
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static.c
> > @@ -0,0 +1 @@
> > +#include "tst-gcs-enforced.c"
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced.c
> > new file mode 100644
> > index 0000000000..608318f26d
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced.c
> > @@ -0,0 +1,2 @@
> > +#define TEST_GCS_EXPECT_ENABLED 1
> > +#include "tst-gcs-skeleton.c"
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-off.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-off.c
> > new file mode 100644
> > index 0000000000..bd688785bb
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-off.c
> > @@ -0,0 +1,2 @@
> > +#define TEST_GCS_EXPECT_ENABLED 0
> > +#include "tst-gcs-skeleton.c"
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-on.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-on.c
> > new file mode 100644
> > index 0000000000..608318f26d
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-on.c
> > @@ -0,0 +1,2 @@
> > +#define TEST_GCS_EXPECT_ENABLED 1
> > +#include "tst-gcs-skeleton.c"
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-off.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-off.c
> > new file mode 100644
> > index 0000000000..54e3b9a0d5
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-off.c
> > @@ -0,0 +1 @@
> > +#include "tst-gcs-optional-off.c"
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-on.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-on.c
> > new file mode 100644
> > index 0000000000..11b884b429
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-on.c
> > @@ -0,0 +1 @@
> > +#include "tst-gcs-optional-on.c"
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override-static.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override-static.c
> > new file mode 100644
> > index 0000000000..09055dcdc4
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override-static.c
> > @@ -0,0 +1 @@
> > +#include "tst-gcs-override.c"
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override.c
> > new file mode 100644
> > index 0000000000..608318f26d
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override.c
> > @@ -0,0 +1,2 @@
> > +#define TEST_GCS_EXPECT_ENABLED 1
> > +#include "tst-gcs-skeleton.c"
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-skeleton.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-skeleton.c
> > new file mode 100644
> > index 0000000000..37692c96d0
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-skeleton.c
> > @@ -0,0 +1,58 @@
> > +/* AArch64 tests for GCS.
> > + 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 <support/check.h>
> > +#include <support/support.h>
> > +#include <support/test-driver.h>
> > +
> > +#include <stdio.h>
> > +#include <sys/auxv.h>
> > +
> > +static bool __check_gcs_status (void)
> > +{
> > + register unsigned long x16 asm ("x16");
> > + asm volatile (
> > + "mov x16, #1 /* _CHKFEAT_GCS */\n"
> > + "hint 40 /* CHKFEAT_X16 */\n"
> > + : "=r" (x16));
> > + return x16 ^ 1;
> > +}
> > +
> > +static int
> > +do_test (void)
> > +{
> > + /* Check if GCS could possible by enabled. */
> > + if (!(getauxval (AT_HWCAP) & HWCAP_GCS))
> > + {
> > + puts ("kernel or CPU does not support GCS");
> > + return EXIT_UNSUPPORTED;
> > + }
> > + bool gcs_enabled = __check_gcs_status ();
> > + if (gcs_enabled)
> > + puts ("GCS enabled");
> > + else
> > + puts ("GCS not enabled");
> > +#if TEST_GCS_EXPECT_ENABLED
> > + TEST_VERIFY (gcs_enabled);
> > +#else
> > + TEST_VERIFY (!gcs_enabled);
> > +#endif
> > + return 0;
> > +}
> > +
> > +#include <support/test-driver.c>
>
> The rest looks ok.
On 28/01/25 07:08, Yury Khrustalev wrote:
> On Mon, Jan 27, 2025 at 05:47:21PM -0300, Adhemerval Zanella Netto wrote:
>>
>> On 23/01/25 11:13, Yury Khrustalev wrote:
>>> These tests validate that GCS tunable works as expected depending
>>> on the GCS markings in the test binaries.
>>>
>>> Tests validate both static and dynamically linked binaries.
>>>
>>> Test will build and run on AArch64 targets only and if GCS is not
>>> enabled on the platform running tests, they will be reported as
>>> UNSUPPORTED.
>>>
>>> When linking tests a new linker command line flag -z gcs=<value>
>>> is used. If the toolchain used to build these tests doesn't support
>>> this flag, there will be a warning that is expected and should be
>>> ignored.
>>
>> I think it would be better to add a configure check for '-z gcs=' support
>> and do not enable them if linker does not support it.
>
> Such an option would only be needed for tests however it may give an
> impression that it can be used for the library code as well which would
> be incorrect. I'm not sure what is the best approach here but it would
> be good to use some sort of test-only configuration.
But this would be done automatically and only enabled during tests, as we
for various linker options on multiple Makefiles like have-test-stb-gnu-unique,
have-fpie, have-test-cc-trampoline, etc.
I don't see much value in building a test that user will need to debug further
to understand what it is failing (for instance on a system with HWCAP_GCS, but
without a toolchain that support -z gcs).
>
>> Making them UNSUPPORTED might be somewhat misleading without also check the
>> build outout for '-z gcs=always ignored', because on systems with HWCAP_GCS
>> it will result in some unexpect results for __check_gcs_status.
>
> This is true, some of the tests will fail on such a system. I'm using assumption
> that the toolchain supports GCS if we intend to run tests on a system that has
> HWCAP_GCS.
> > Please note that there is v2 of this series:
> https://inbox.sourceware.org/libc-alpha/20250124122858.3788655-1-yury.khrustalev@arm.com/
Right, I missed that. I will focus on this version.
>
>>> ---
>>> sysdeps/unix/sysv/linux/aarch64/Makefile | 64 +++++++++++++++++++
>>> .../unix/sysv/linux/aarch64/tst-gcs-abort.sh | 40 ++++++++++++
>>> .../linux/aarch64/tst-gcs-disabled-static.c | 1 +
>>> .../sysv/linux/aarch64/tst-gcs-disabled.c | 2 +
>>> .../linux/aarch64/tst-gcs-enforced-abort.c | 2 +
>>> .../aarch64/tst-gcs-enforced-static-abort.c | 1 +
>>> .../linux/aarch64/tst-gcs-enforced-static.c | 1 +
>>> .../sysv/linux/aarch64/tst-gcs-enforced.c | 2 +
>>> .../sysv/linux/aarch64/tst-gcs-optional-off.c | 2 +
>>> .../sysv/linux/aarch64/tst-gcs-optional-on.c | 2 +
>>> .../aarch64/tst-gcs-optional-static-off.c | 1 +
>>> .../aarch64/tst-gcs-optional-static-on.c | 1 +
>>> .../linux/aarch64/tst-gcs-override-static.c | 1 +
>>> .../sysv/linux/aarch64/tst-gcs-override.c | 2 +
>>> .../sysv/linux/aarch64/tst-gcs-skeleton.c | 58 +++++++++++++++++
>>> 15 files changed, 180 insertions(+)
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled-static.c
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled.c
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-abort.c
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static-abort.c
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static.c
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced.c
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-off.c
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-on.c
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-off.c
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-on.c
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-override-static.c
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-override.c
>>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/tst-gcs-skeleton.c
>>>
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/Makefile b/sysdeps/unix/sysv/linux/aarch64/Makefile
>>> index 1fdad67fae..82a992bc14 100644
>>> --- a/sysdeps/unix/sysv/linux/aarch64/Makefile
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/Makefile
>>> @@ -1,8 +1,72 @@
>>> ifeq ($(subdir),misc)
>>> sysdep_headers += sys/elf.h
>>> +
>>> +gcs-tests-dynamic = \
>>> + tst-gcs-disabled \
>>> + tst-gcs-enforced \
>>> + tst-gcs-enforced-abort \
>>> + tst-gcs-optional-off \
>>> + tst-gcs-optional-on \
>>> + tst-gcs-override \
>>> + # gcs-tests-dynamic
>>> +
>>> +gcs-tests-static = \
>>> + tst-gcs-disabled-static \
>>> + tst-gcs-enforced-static \
>>> + tst-gcs-enforced-static-abort \
>>> + tst-gcs-optional-static-off \
>>> + tst-gcs-optional-static-on \
>>> + tst-gcs-override-static \
>>> + # gcs-tests-static
>>> +
>>> tests += \
>>> + $(gcs-tests-dynamic) \
>>> + $(gcs-tests-static) \
>>> tst-aarch64-pkey \
>>> # tests
>>> +
>>> +tests-static += \
>>> + $(gcs-tests-static) \
>>> + # tests-static
>>> +
>>> +define run-gcs-abort-test
>>> + $(test-wrapper-env) $(run-program-env) \
>>> + $(tst-gcs-$*-abort-ENV) $(host-test-program-cmd)
>>> +endef
>>> +
>>> +$(objpfx)tst-gcs-%-abort.out: $(..)sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh \
>>> + $(objpfx)tst-gcs-%-abort
>>> + $(SHELL) $< $(common-objpfx) $(test-name) '$(run-gcs-abort-test)'; \
>>> + $(evaluate-test)
>>> +
>>> +LDFLAGS-tst-gcs-disabled += -Wl,-z gcs=always
>>> +LDFLAGS-tst-gcs-enforced += -Wl,-z gcs=always
>>> +LDFLAGS-tst-gcs-enforced-abort += -Wl,-z gcs=never
>>> +LDFLAGS-tst-gcs-optional-on += -Wl,-z gcs=always
>>> +LDFLAGS-tst-gcs-optional-off += -Wl,-z gcs=never
>>> +LDFLAGS-tst-gcs-override += -Wl,-z gcs=never
>>> +
>>> +LDFLAGS-tst-gcs-disabled-static += -Wl,-z gcs=always
>>> +LDFLAGS-tst-gcs-enforced-static += -Wl,-z gcs=always
>>> +LDFLAGS-tst-gcs-enforced-static-abort += -Wl,-z gcs=never
>>> +LDFLAGS-tst-gcs-optional-static-on += -Wl,-z gcs=always
>>> +LDFLAGS-tst-gcs-optional-static-off += -Wl,-z gcs=never
>>> +LDFLAGS-tst-gcs-override-static += -Wl,-z gcs=never
>>> +
>>> +tst-gcs-disabled-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=0
>>> +tst-gcs-enforced-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
>>> +tst-gcs-enforced-abort-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
>>> +tst-gcs-optional-on-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
>>> +tst-gcs-optional-off-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
>>> +tst-gcs-override-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=3
>>> +
>>> +tst-gcs-disabled-static-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=0
>>> +tst-gcs-enforced-static-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
>>> +tst-gcs-enforced-static-abort-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
>>> +tst-gcs-optional-static-on-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
>>> +tst-gcs-optional-static-off-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
>>> +tst-gcs-override-static-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=3
>>> +
>>> endif
>>>
>>> ifeq ($(subdir),stdlib)
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh
>>> new file mode 100644
>>> index 0000000000..5c1889bfcd
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh
>>> @@ -0,0 +1,40 @@
>>> +#!/bin/sh
>>> +# Test wrapper for AArch64 tests for GCS that are expected to abort.
>>> +# Copyright (C) 2001-2025 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 $status -eq 127 \
>>> + && grep -q -w "not GCS compatible" "$logfile" ; then
>>> + exit 0
>>> +elif test $status -eq 77; then
>>> + exit 77
>>> +else
>>> + echo "unexpected test output or exit status $status"
>>> + exit 1
>>> +fi
>>> +
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled-static.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled-static.c
>>> new file mode 100644
>>> index 0000000000..c71d68cb86
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled-static.c
>>> @@ -0,0 +1 @@
>>> +#include "tst-gcs-disabled.c"
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled.c
>>> new file mode 100644
>>> index 0000000000..bd688785bb
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-disabled.c
>>> @@ -0,0 +1,2 @@
>>> +#define TEST_GCS_EXPECT_ENABLED 0
>>> +#include "tst-gcs-skeleton.c"
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-abort.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-abort.c
>>> new file mode 100644
>>> index 0000000000..608318f26d
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-abort.c
>>> @@ -0,0 +1,2 @@
>>> +#define TEST_GCS_EXPECT_ENABLED 1
>>> +#include "tst-gcs-skeleton.c"
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static-abort.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static-abort.c
>>> new file mode 100644
>>> index 0000000000..c20a999f6b
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static-abort.c
>>> @@ -0,0 +1 @@
>>> +#include "tst-gcs-enforced-abort.c"
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static.c
>>> new file mode 100644
>>> index 0000000000..bb39dada55
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced-static.c
>>> @@ -0,0 +1 @@
>>> +#include "tst-gcs-enforced.c"
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced.c
>>> new file mode 100644
>>> index 0000000000..608318f26d
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-enforced.c
>>> @@ -0,0 +1,2 @@
>>> +#define TEST_GCS_EXPECT_ENABLED 1
>>> +#include "tst-gcs-skeleton.c"
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-off.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-off.c
>>> new file mode 100644
>>> index 0000000000..bd688785bb
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-off.c
>>> @@ -0,0 +1,2 @@
>>> +#define TEST_GCS_EXPECT_ENABLED 0
>>> +#include "tst-gcs-skeleton.c"
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-on.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-on.c
>>> new file mode 100644
>>> index 0000000000..608318f26d
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-on.c
>>> @@ -0,0 +1,2 @@
>>> +#define TEST_GCS_EXPECT_ENABLED 1
>>> +#include "tst-gcs-skeleton.c"
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-off.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-off.c
>>> new file mode 100644
>>> index 0000000000..54e3b9a0d5
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-off.c
>>> @@ -0,0 +1 @@
>>> +#include "tst-gcs-optional-off.c"
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-on.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-on.c
>>> new file mode 100644
>>> index 0000000000..11b884b429
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-optional-static-on.c
>>> @@ -0,0 +1 @@
>>> +#include "tst-gcs-optional-on.c"
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override-static.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override-static.c
>>> new file mode 100644
>>> index 0000000000..09055dcdc4
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override-static.c
>>> @@ -0,0 +1 @@
>>> +#include "tst-gcs-override.c"
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override.c
>>> new file mode 100644
>>> index 0000000000..608318f26d
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-override.c
>>> @@ -0,0 +1,2 @@
>>> +#define TEST_GCS_EXPECT_ENABLED 1
>>> +#include "tst-gcs-skeleton.c"
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/tst-gcs-skeleton.c b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-skeleton.c
>>> new file mode 100644
>>> index 0000000000..37692c96d0
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/tst-gcs-skeleton.c
>>> @@ -0,0 +1,58 @@
>>> +/* AArch64 tests for GCS.
>>> + 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 <support/check.h>
>>> +#include <support/support.h>
>>> +#include <support/test-driver.h>
>>> +
>>> +#include <stdio.h>
>>> +#include <sys/auxv.h>
>>> +
>>> +static bool __check_gcs_status (void)
>>> +{
>>> + register unsigned long x16 asm ("x16");
>>> + asm volatile (
>>> + "mov x16, #1 /* _CHKFEAT_GCS */\n"
>>> + "hint 40 /* CHKFEAT_X16 */\n"
>>> + : "=r" (x16));
>>> + return x16 ^ 1;
>>> +}
>>> +
>>> +static int
>>> +do_test (void)
>>> +{
>>> + /* Check if GCS could possible by enabled. */
>>> + if (!(getauxval (AT_HWCAP) & HWCAP_GCS))
>>> + {
>>> + puts ("kernel or CPU does not support GCS");
>>> + return EXIT_UNSUPPORTED;
>>> + }
>>> + bool gcs_enabled = __check_gcs_status ();
>>> + if (gcs_enabled)
>>> + puts ("GCS enabled");
>>> + else
>>> + puts ("GCS not enabled");
>>> +#if TEST_GCS_EXPECT_ENABLED
>>> + TEST_VERIFY (gcs_enabled);
>>> +#else
>>> + TEST_VERIFY (!gcs_enabled);
>>> +#endif
>>> + return 0;
>>> +}
>>> +
>>> +#include <support/test-driver.c>
>>
>> The rest looks ok.
On Tue, Jan 28, 2025 at 08:49:00AM -0300, Adhemerval Zanella Netto wrote:
>
> On 28/01/25 07:08, Yury Khrustalev wrote:
> > On Mon, Jan 27, 2025 at 05:47:21PM -0300, Adhemerval Zanella Netto wrote:
> >>
> >> On 23/01/25 11:13, Yury Khrustalev wrote:
> >>> These tests validate that GCS tunable works as expected depending
> >>> on the GCS markings in the test binaries.
> >>>
> >>> Tests validate both static and dynamically linked binaries.
> >>>
> >>> Test will build and run on AArch64 targets only and if GCS is not
> >>> enabled on the platform running tests, they will be reported as
> >>> UNSUPPORTED.
> >>>
> >>> When linking tests a new linker command line flag -z gcs=<value>
> >>> is used. If the toolchain used to build these tests doesn't support
> >>> this flag, there will be a warning that is expected and should be
> >>> ignored.
> >>
> >> I think it would be better to add a configure check for '-z gcs=' support
> >> and do not enable them if linker does not support it.
> >
> > Such an option would only be needed for tests however it may give an
> > impression that it can be used for the library code as well which would
> > be incorrect. I'm not sure what is the best approach here but it would
> > be good to use some sort of test-only configuration.
>
> But this would be done automatically and only enabled during tests, as we
> for various linker options on multiple Makefiles like have-test-stb-gnu-unique,
> have-fpie, have-test-cc-trampoline, etc.
Would LIBC_LINKER_FEATURE be appropriate here. I see that for compiler flags
support there is a desinction between CC and TEST_CC so probably it's the
same for linker? But I can't find something like LIBC_TEST_LINKER_FEATURE.
Kind regards,
Yury
On 28/01/25 10:23, Yury Khrustalev wrote:
> On Tue, Jan 28, 2025 at 08:49:00AM -0300, Adhemerval Zanella Netto wrote:
>>
>> On 28/01/25 07:08, Yury Khrustalev wrote:
>>> On Mon, Jan 27, 2025 at 05:47:21PM -0300, Adhemerval Zanella Netto wrote:
>>>>
>>>> On 23/01/25 11:13, Yury Khrustalev wrote:
>>>>> These tests validate that GCS tunable works as expected depending
>>>>> on the GCS markings in the test binaries.
>>>>>
>>>>> Tests validate both static and dynamically linked binaries.
>>>>>
>>>>> Test will build and run on AArch64 targets only and if GCS is not
>>>>> enabled on the platform running tests, they will be reported as
>>>>> UNSUPPORTED.
>>>>>
>>>>> When linking tests a new linker command line flag -z gcs=<value>
>>>>> is used. If the toolchain used to build these tests doesn't support
>>>>> this flag, there will be a warning that is expected and should be
>>>>> ignored.
>>>>
>>>> I think it would be better to add a configure check for '-z gcs=' support
>>>> and do not enable them if linker does not support it.
>>>
>>> Such an option would only be needed for tests however it may give an
>>> impression that it can be used for the library code as well which would
>>> be incorrect. I'm not sure what is the best approach here but it would
>>> be good to use some sort of test-only configuration.
>>
>> But this would be done automatically and only enabled during tests, as we
>> for various linker options on multiple Makefiles like have-test-stb-gnu-unique,
>> have-fpie, have-test-cc-trampoline, etc.
>
> Would LIBC_LINKER_FEATURE be appropriate here. I see that for compiler flags
> support there is a desinction between CC and TEST_CC so probably it's the
> same for linker? But I can't find something like LIBC_TEST_LINKER_FEATURE.
I think we should LIBC_LINKER_FEATURE for now, it is used on some tests enablement
like have-z-execstack. But the CC and TEST_CC is a good point and we might
get back to this if/when CC and TEST_CC uses a liker with different support
(which I think was not taking in consideration for TEST_CC addition).
On Tue, Jan 28, 2025 at 11:28:40AM -0300, Adhemerval Zanella Netto wrote:
>
> > Would LIBC_LINKER_FEATURE be appropriate here. I see that for compiler flags
> > support there is a desinction between CC and TEST_CC so probably it's the
> > same for linker? But I can't find something like LIBC_TEST_LINKER_FEATURE.
>
> I think we should LIBC_LINKER_FEATURE for now, it is used on some tests enablement
> like have-z-execstack. But the CC and TEST_CC is a good point and we might
> get back to this if/when CC and TEST_CC uses a liker with different support
> (which I think was not taking in consideration for TEST_CC addition).
Thanks, I've sent v3 with the new configure check that allows to only enable
GCS tests if toolchain supports them, and then it run on both systems with
and without GCS (UNSUPPORTED in the latter case).
https://inbox.sourceware.org/libc-alpha/20250129094940.2643944-1-yury.khrustalev@arm.com/
Kind regards,
Yury
@@ -1,8 +1,72 @@
ifeq ($(subdir),misc)
sysdep_headers += sys/elf.h
+
+gcs-tests-dynamic = \
+ tst-gcs-disabled \
+ tst-gcs-enforced \
+ tst-gcs-enforced-abort \
+ tst-gcs-optional-off \
+ tst-gcs-optional-on \
+ tst-gcs-override \
+ # gcs-tests-dynamic
+
+gcs-tests-static = \
+ tst-gcs-disabled-static \
+ tst-gcs-enforced-static \
+ tst-gcs-enforced-static-abort \
+ tst-gcs-optional-static-off \
+ tst-gcs-optional-static-on \
+ tst-gcs-override-static \
+ # gcs-tests-static
+
tests += \
+ $(gcs-tests-dynamic) \
+ $(gcs-tests-static) \
tst-aarch64-pkey \
# tests
+
+tests-static += \
+ $(gcs-tests-static) \
+ # tests-static
+
+define run-gcs-abort-test
+ $(test-wrapper-env) $(run-program-env) \
+ $(tst-gcs-$*-abort-ENV) $(host-test-program-cmd)
+endef
+
+$(objpfx)tst-gcs-%-abort.out: $(..)sysdeps/unix/sysv/linux/aarch64/tst-gcs-abort.sh \
+ $(objpfx)tst-gcs-%-abort
+ $(SHELL) $< $(common-objpfx) $(test-name) '$(run-gcs-abort-test)'; \
+ $(evaluate-test)
+
+LDFLAGS-tst-gcs-disabled += -Wl,-z gcs=always
+LDFLAGS-tst-gcs-enforced += -Wl,-z gcs=always
+LDFLAGS-tst-gcs-enforced-abort += -Wl,-z gcs=never
+LDFLAGS-tst-gcs-optional-on += -Wl,-z gcs=always
+LDFLAGS-tst-gcs-optional-off += -Wl,-z gcs=never
+LDFLAGS-tst-gcs-override += -Wl,-z gcs=never
+
+LDFLAGS-tst-gcs-disabled-static += -Wl,-z gcs=always
+LDFLAGS-tst-gcs-enforced-static += -Wl,-z gcs=always
+LDFLAGS-tst-gcs-enforced-static-abort += -Wl,-z gcs=never
+LDFLAGS-tst-gcs-optional-static-on += -Wl,-z gcs=always
+LDFLAGS-tst-gcs-optional-static-off += -Wl,-z gcs=never
+LDFLAGS-tst-gcs-override-static += -Wl,-z gcs=never
+
+tst-gcs-disabled-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=0
+tst-gcs-enforced-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
+tst-gcs-enforced-abort-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
+tst-gcs-optional-on-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
+tst-gcs-optional-off-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
+tst-gcs-override-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=3
+
+tst-gcs-disabled-static-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=0
+tst-gcs-enforced-static-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
+tst-gcs-enforced-static-abort-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=1
+tst-gcs-optional-static-on-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
+tst-gcs-optional-static-off-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=2
+tst-gcs-override-static-ENV = GLIBC_TUNABLES=glibc.cpu.aarch64_gcs=3
+
endif
ifeq ($(subdir),stdlib)
new file mode 100644
@@ -0,0 +1,40 @@
+#!/bin/sh
+# Test wrapper for AArch64 tests for GCS that are expected to abort.
+# Copyright (C) 2001-2025 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 $status -eq 127 \
+ && grep -q -w "not GCS compatible" "$logfile" ; then
+ exit 0
+elif test $status -eq 77; then
+ exit 77
+else
+ echo "unexpected test output or exit status $status"
+ exit 1
+fi
+
new file mode 100644
@@ -0,0 +1 @@
+#include "tst-gcs-disabled.c"
new file mode 100644
@@ -0,0 +1,2 @@
+#define TEST_GCS_EXPECT_ENABLED 0
+#include "tst-gcs-skeleton.c"
new file mode 100644
@@ -0,0 +1,2 @@
+#define TEST_GCS_EXPECT_ENABLED 1
+#include "tst-gcs-skeleton.c"
new file mode 100644
@@ -0,0 +1 @@
+#include "tst-gcs-enforced-abort.c"
new file mode 100644
@@ -0,0 +1 @@
+#include "tst-gcs-enforced.c"
new file mode 100644
@@ -0,0 +1,2 @@
+#define TEST_GCS_EXPECT_ENABLED 1
+#include "tst-gcs-skeleton.c"
new file mode 100644
@@ -0,0 +1,2 @@
+#define TEST_GCS_EXPECT_ENABLED 0
+#include "tst-gcs-skeleton.c"
new file mode 100644
@@ -0,0 +1,2 @@
+#define TEST_GCS_EXPECT_ENABLED 1
+#include "tst-gcs-skeleton.c"
new file mode 100644
@@ -0,0 +1 @@
+#include "tst-gcs-optional-off.c"
new file mode 100644
@@ -0,0 +1 @@
+#include "tst-gcs-optional-on.c"
new file mode 100644
@@ -0,0 +1 @@
+#include "tst-gcs-override.c"
new file mode 100644
@@ -0,0 +1,2 @@
+#define TEST_GCS_EXPECT_ENABLED 1
+#include "tst-gcs-skeleton.c"
new file mode 100644
@@ -0,0 +1,58 @@
+/* AArch64 tests for GCS.
+ 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 <support/check.h>
+#include <support/support.h>
+#include <support/test-driver.h>
+
+#include <stdio.h>
+#include <sys/auxv.h>
+
+static bool __check_gcs_status (void)
+{
+ register unsigned long x16 asm ("x16");
+ asm volatile (
+ "mov x16, #1 /* _CHKFEAT_GCS */\n"
+ "hint 40 /* CHKFEAT_X16 */\n"
+ : "=r" (x16));
+ return x16 ^ 1;
+}
+
+static int
+do_test (void)
+{
+ /* Check if GCS could possible by enabled. */
+ if (!(getauxval (AT_HWCAP) & HWCAP_GCS))
+ {
+ puts ("kernel or CPU does not support GCS");
+ return EXIT_UNSUPPORTED;
+ }
+ bool gcs_enabled = __check_gcs_status ();
+ if (gcs_enabled)
+ puts ("GCS enabled");
+ else
+ puts ("GCS not enabled");
+#if TEST_GCS_EXPECT_ENABLED
+ TEST_VERIFY (gcs_enabled);
+#else
+ TEST_VERIFY (!gcs_enabled);
+#endif
+ return 0;
+}
+
+#include <support/test-driver.c>