Commit 4f2930c6 authored by Adam Sindelar's avatar Adam Sindelar Committed by Andrew Morton
Browse files

selftests/vm: only run 128TBswitch with 5-level paging 

The test va_128TBswitch.c expects to be able to pass mmap an address hint
and length that cross the address 1<<47.  On x86_64, 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_64 archs, but this
patch adds an additional check on x86_64 that skips the test if
PG_TABLE_LEVELS < 5.  There is precedent for checking /proc/config.gz in
selftests, e.g.  in selftests/firmware.

Running the tests produces the desired output:

sudo make -C tools/testing/selftests TARGETS=vm run_tests
---------------------------
running ./va_128TBswitch.sh
---------------------------
./va_128TBswitch.sh: PG_TABLE_LEVELS=4, must be >= 5 to run this test
[SKIP]
-------------------------------

[adam@wowsignal.io: restrict the check to x86_64]
  Link: https://lkml.kernel.org/r/20220628163654.337600-1-adam@wowsignal.io
[adam@wowsignal.io: fix formatting issues, rename "die" to "fail"]
  Link: https://lkml.kernel.org/r/20220701163030.415735-1-adam@wowsignal.io
Link: https://lkml.kernel.org/r/20220627163912.5581-1-adam@wowsignal.io


Signed-off-by: default avatarAdam Sindelar <adam@wowsignal.io>
Cc: Adam Sindelar <ats@fb.com>
Cc: David Vernet <void@manifault.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 1baec203

tools/testing/selftests/vm/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -93,6 +93,7 @@ TEST_PROGS := run_vmtests.sh 


TEST_FILES := test_vmalloc.sh

TEST_FILES += test_hmm.sh

TEST_FILES += va_128TBswitch.sh



KSFT_KHDR_INSTALL := 1

include ../lib.mk

tools/testing/selftests/vm/run_vmtests.sh

+1 −1
Original line number Diff line number Diff line
@@ -151,7 +151,7 @@ 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

tools/testing/selftests/vm/va_128TBswitch.sh

0 → 100644
+54 −0
Original line number Diff line number Diff line 
#!/bin/bash

# SPDX-License-Identifier: GPL-2.0

#

# Copyright (C) 2022 Adam Sindelar (Meta) <adam@wowsignal.io>

#

# 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



# Kselftest framework requirement - SKIP code is 4.

ksft_skip=4



fail()

{

	echo "$1"

	exit $exitcode

}



check_supported_x86_64()

{

	local config="/proc/config.gz"

	[[ -f "${config}" ]] || config="/boot/config-$(uname -r)"

	[[ -f "${config}" ]] || fail "Cannot find kernel config in /proc or /boot"



	# gzip -dcfq automatically handles both compressed and plaintext input.

	# See man 1 gzip under '-f'.

	local pg_table_levels=$(gzip -dcfq "${config}" | grep PGTABLE_LEVELS | cut -d'=' -f 2)



	if [[ "${pg_table_levels}" -lt 5 ]]; then

		echo "$0: PGTABLE_LEVELS=${pg_table_levels}, must be >= 5 to run this test"

		exit $ksft_skip

	fi

}



check_test_requirements()

{

	# The test supports x86_64 and powerpc64. We currently have no useful

	# eligibility check for powerpc64, and the test itself will reject other

	# architectures.

	case `uname -m` in

		"x86_64")

			check_supported_x86_64

		;;

		*)

			return 0

		;;

	esac

}



check_test_requirements

./va_128TBswitch