On Tue, Jun 28, 2022 at 08:49:42PM +0530, Aneesh Kumar K.V wrote:
> Adam Sindelar <adam@xxxxxxxxxxxx> writes:
>
> > 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.
> >
> > 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]
> > -------------------------------
> >
> > Signed-off-by: Adam Sindelar <adam@xxxxxxxxxxxx>
> > ---
> > V2 -> V3: Clean up the commit message
> > V1 -> V2: Variables local, fixed Makefile typo, comment on gzip usage
> >
> > tools/testing/selftests/vm/Makefile | 1 +
> > tools/testing/selftests/vm/run_vmtests.sh | 2 +-
> > tools/testing/selftests/vm/va_128TBswitch.sh | 39 ++++++++++++++++++++
> > 3 files changed, 41 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..7860d0969888 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
> >
> > 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..767a6465b5d2
> > --- /dev/null
> > +++ b/tools/testing/selftests/vm/va_128TBswitch.sh
> > @@ -0,0 +1,39 @@
> > +#!/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
> > +
> > +# Kselftest framework requirement - SKIP code is 4.
> > +ksft_skip=4
> > +
> > +die()
> > +{
> > + echo "$1"
> > + exit $exitcode
> > +}
> > +
> > +check_test_requirements()
> > +{
> > + local config="/proc/config.gz"
> > + [[ -f "${config}" ]] || config="/boot/config-$(uname -r)"
> > + [[ -f "${config}" ]] || die "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 "$0: PG_TABLE_LEVELS=${pg_table_levels}, must be >= 5 to run this test"
> > + exit $ksft_skip
> > + fi
> > +}
>
> This prevent the test from running on powerpc architecture.
>
> $bash -x ./va_128TBswitch.sh
> + exitcode=1
> + ksft_skip=4
> + check_test_requirements
> + local config=/proc/config.gz
> + [[ -f /proc/config.gz ]]
> + [[ -f /proc/config.gz ]]
> ++ gzip -dcfq /proc/config.gz
> ++ grep PGTABLE_LEVELS
> ++ cut -d= -f 2
> + local pg_table_levels=4
> + [[ 4 -lt 5 ]]
> + echo './va_128TBswitch.sh: PG_TABLE_LEVELS=4, must be >= 5 to run this test'
> ./va_128TBswitch.sh: PG_TABLE_LEVELS=4, must be >= 5 to run this test
> + exit 4
>
> Without the patch
>
> :src/linux/tools/testing/selftests/vm$ ./va_128TBswitch
> mmap(ADDR_SWITCH_HINT - PAGE_SIZE, PAGE_SIZE): 0x7fffffff0000 - OK
> mmap(ADDR_SWITCH_HINT - PAGE_SIZE, (2 * PAGE_SIZE)): 0x763910f30000 - OK
> mmap(ADDR_SWITCH_HINT, PAGE_SIZE): 0x763910f40000 - OK
> mmap(ADDR_SWITCH_HINT, 2 * PAGE_SIZE, MAP_FIXED): 0x800000000000 - OK
> mmap(NULL): 0x763910f20000 - OK
> mmap(LOW_ADDR): 0x40000000 - OK
> mmap(HIGH_ADDR): 0x1000000000000 - OK
> mmap(HIGH_ADDR) again: 0xff63910fc0000 - OK
> mmap(HIGH_ADDR, MAP_FIXED): 0x1000000000000 - OK
> mmap(-1): 0xff63910fa0000 - OK
> mmap(-1) again: 0xff63910f80000 - OK
> mmap(ADDR_SWITCH_HINT - PAGE_SIZE, PAGE_SIZE): 0x7fffffff0000 - OK
> mmap(ADDR_SWITCH_HINT - PAGE_SIZE, 2 * PAGE_SIZE): 0x763910f20000 - OK
> mmap(ADDR_SWITCH_HINT - PAGE_SIZE/2 , 2 * PAGE_SIZE): 0x763910f00000 - OK
> mmap(ADDR_SWITCH_HINT, PAGE_SIZE): 0x763910ef0000 - OK
> mmap(ADDR_SWITCH_HINT, 2 * PAGE_SIZE, MAP_FIXED): 0x800000000000 - OK
> > +
> > +check_test_requirements
> > +./va_128TBswitch
> > --
> > 2.35.1
My bad, sorry. Let me fix it in v4.
