On Mon, Jun 27, 2022 at 02:31:06PM +0200, Adam Sindelar wrote:
> The test va_128TBswitch.c expects to be able to pass mmap an address hint
> and length that cross the address 1<<47. This is not possible without
> 5-level page tables, so the test fails.
>
> The test is already only run on 64-bit powerpc and x86 archs, but this
> patch adds an additional check that skips the test if PG_TABLE_LEVELS < 5.
> There is precedent for checking /proc/config.gz in selftests, e.g. in
> selftests/firmware.
>
> Signed-off-by: Adam Sindelar <adam@xxxxxxxxxxxx>
Hi Adam,
Thanks for the patch. This is a great start -- left a few comments and
questions.
> ---
> tools/testing/selftests/vm/Makefile | 1 +
> tools/testing/selftests/vm/run_vmtests.sh | 2 +-
> tools/testing/selftests/vm/va_128TBswitch.sh | 37 ++++++++++++++++++++
> 3 files changed, 39 insertions(+), 1 deletion(-)
> create mode 100755 tools/testing/selftests/vm/va_128TBswitch.sh
>
> diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
> index c45e535ff4b8..74390f498859 100644
> --- a/tools/testing/selftests/vm/Makefile
> +++ b/tools/testing/selftests/vm/Makefile
> @@ -91,6 +91,7 @@ endif
> TEST_PROGS := run_vmtests.sh
>
> TEST_FILES := test_vmalloc.sh
> +TEST_FILEs += va_128TBswitch.sh
s/TEST_FILEs/TEST_FILES
I recommend verifying that the installation worked as expected by running:
$ make -C tools/testing/selftests TARGETS=vm install
and ensuring that the shell script is output into
tools/testing/selftests/kselftest_install/vm
> KSFT_KHDR_INSTALL := 1
> include ../lib.mk
> diff --git a/tools/testing/selftests/vm/run_vmtests.sh b/tools/testing/selftests/vm/run_vmtests.sh
> index a2302b5faaf2..edda7350ccca 100755
> --- a/tools/testing/selftests/vm/run_vmtests.sh
> +++ b/tools/testing/selftests/vm/run_vmtests.sh
> @@ -149,7 +149,7 @@ if [ $VADDR64 -ne 0 ]; then
> run_test ./virtual_address_range
>
> # virtual address 128TB switch test
> - run_test ./va_128TBswitch
> + run_test ./va_128TBswitch.sh
> fi # VADDR64
>
> # vmalloc stability smoke test
> diff --git a/tools/testing/selftests/vm/va_128TBswitch.sh b/tools/testing/selftests/vm/va_128TBswitch.sh
> new file mode 100755
> index 000000000000..269cc674fe9e
> --- /dev/null
> +++ b/tools/testing/selftests/vm/va_128TBswitch.sh
> @@ -0,0 +1,37 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# Copyright (C) 2022 Adam Sindelar (Meta) <adam@xxxxxxxxxxxx>
> +#
> +# This is a test for mmap behavior with 5-level paging. This script wraps the
> +# real test to check that the kernel is configured to support at least 5
> +# pagetable levels.
> +
> +# 1 means the test failed
> +exitcode=1
Should we change this to ksft_fail to match ksft_skip?
> +
> +# Kselftest framework requirement - SKIP code is 4.
> +ksft_skip=4
> +
> +die()
> +{
> + echo "$1"
> + exit $exitcode
> +}
> +
> +check_test_requirements()
> +{
> + config="/proc/config.gz"
Can you make this variable local?
> + [[ -f "${config}" ]] || config="/boot/config-$(uname -r)"
> + [[ -f "${config}" ]] || die "Cannot find kernel config in /proc or /boot"
> +
> + pg_table_levels=$(gzip -dcfq "${config}" | grep PGTABLE_LEVELS | cut -d'=' -f 2)
Same here r.e. making it local.
Also, does this work if we end up having to pull config from /boot where
it's not gzipped? Perhaps we should create a variable called something like
'configs' which stores the output as either:
$ local configs="$(zcat /proc/config.gz)"
or
$ local configs="$(cat /boot/config-$(uname -r))"
Also, to the point above, just using zcat might be a bit simpler than
invoking gzip -dcfq.
> + if [[ "${pg_table_levels}" -lt 5 ]]; then
> + echo "$0: PG_TABLE_LEVELS=${pg_table_levels}, must be >= 5 to run this test"
> + exit $ksft_skip
> + fi
> +}
> +
> +check_test_requirements
> +./va_128TBswitch
> --
> 2.35.1
>
Thanks,
David
