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]
-------------------------------
Signed-off-by: Adam Sindelar <adam@xxxxxxxxxxxx>
---
V4 -> V5: Renamed "die" to "fail" (missed the review comment, sorry!)
V3 -> V4: Restrict the check to x86_64
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 | 54 ++++++++++++++++++++
3 files changed, 56 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 44f25acfbeca..6a34209379a4 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -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
diff --git a/tools/testing/selftests/vm/run_vmtests.sh b/tools/testing/selftests/vm/run_vmtests.sh
index 41fce8bea929..27c01c35c7a9 100755
--- a/tools/testing/selftests/vm/run_vmtests.sh
+++ b/tools/testing/selftests/vm/run_vmtests.sh
@@ -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
diff --git a/tools/testing/selftests/vm/va_128TBswitch.sh b/tools/testing/selftests/vm/va_128TBswitch.sh
new file mode 100755
index 000000000000..334d12715ac3
--- /dev/null
+++ b/tools/testing/selftests/vm/va_128TBswitch.sh
@@ -0,0 +1,54 @@
+#!/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
+
+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
--
2.35.1
