From 9308f2f9e7f055cf3934645ec622bb5259dc1c14 Mon Sep 17 00:00:00 2001
From: "Luis R. Rodriguez" <mcgrof@kernel.org>
Date: Wed, 12 Jul 2017 14:33:43 -0700
Subject: test_sysctl: add dedicated proc sysctl test driver

The existing tools/testing/selftests/sysctl/ tests include two test
cases, but these use existing production kernel sysctl interfaces.  We
want to expand test coverage but we can't just be looking for random
safe production values to poke at, that's just insane!

Instead just dedicate a test driver for debugging purposes and port the
existing scripts to use it.  This will make it easier for further tests
to be added.

Subsequent patches will extend our test coverage for sysctl.

The stress test driver uses a new license (GPL on Linux, copyleft-next
outside of Linux).  Linus was fine with this [0] and later due to Ted's
and Alans's request ironed out an "or" language clause to use [1] which
is already present upstream.

[0] https://lkml.kernel.org/r/CA+55aFyhxcvD+q7tp+-yrSFDKfR0mOHgyEAe=f_94aKLsOu0Og@mail.gmail.com
[1] https://lkml.kernel.org/r/1495234558.7848.122.camel@linux.intel.com

Link: http://lkml.kernel.org/r/20170630224431.17374-2-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 tools/testing/selftests/sysctl/config           | 1 +
 tools/testing/selftests/sysctl/run_numerictests | 4 ++--
 tools/testing/selftests/sysctl/run_stringtests  | 4 ++--
 3 files changed, 5 insertions(+), 4 deletions(-)
 create mode 100644 tools/testing/selftests/sysctl/config

(limited to 'tools')

diff --git a/tools/testing/selftests/sysctl/config b/tools/testing/selftests/sysctl/config
new file mode 100644
index 000000000000..6ca14800d755
--- /dev/null
+++ b/tools/testing/selftests/sysctl/config
@@ -0,0 +1 @@
+CONFIG_TEST_SYSCTL=y
diff --git a/tools/testing/selftests/sysctl/run_numerictests b/tools/testing/selftests/sysctl/run_numerictests
index e6e76c93d948..c375ce0f4c15 100755
--- a/tools/testing/selftests/sysctl/run_numerictests
+++ b/tools/testing/selftests/sysctl/run_numerictests
@@ -1,7 +1,7 @@
 #!/bin/sh
 
-SYSCTL="/proc/sys"
-TARGET="${SYSCTL}/vm/swappiness"
+SYSCTL="/proc/sys/debug/test_sysctl/"
+TARGET="${SYSCTL}/int_0001"
 ORIG=$(cat "${TARGET}")
 TEST_STR=$(( $ORIG + 1 ))
 
diff --git a/tools/testing/selftests/sysctl/run_stringtests b/tools/testing/selftests/sysctl/run_stringtests
index 857ec667fb02..a6f2618afeaa 100755
--- a/tools/testing/selftests/sysctl/run_stringtests
+++ b/tools/testing/selftests/sysctl/run_stringtests
@@ -1,7 +1,7 @@
 #!/bin/sh
 
-SYSCTL="/proc/sys"
-TARGET="${SYSCTL}/kernel/domainname"
+SYSCTL="/proc/sys/debug/test_sysctl/"
+TARGET="${SYSCTL}/string_0001"
 ORIG=$(cat "${TARGET}")
 TEST_STR="Testing sysctl"
 
-- 
cgit v1.2.3


From 64b671204afd71591e774e7237b7c862ac5bbd97 Mon Sep 17 00:00:00 2001
From: "Luis R. Rodriguez" <mcgrof@kernel.org>
Date: Wed, 12 Jul 2017 14:33:46 -0700
Subject: test_sysctl: add generic script to expand on tests

This adds a generic script to let us more easily add more tests cases.
Since we really have only two types of tests cases just fold them into
the one file.  Each test unit is now identified into its separate
function:

    # ./sysctl.sh -l
  Test ID list:

  TEST_ID x NUM_TEST
  TEST_ID:   Test ID
  NUM_TESTS: Number of recommended times to run the test

  0001 x 1 - tests proc_dointvec_minmax()
  0002 x 1 - tests proc_dostring()

For now we start off with what we had before, and run only each test
once.  We can now watch a test case until it fails:

  ./sysctl.sh -w 0002

We can also run a test case x number of times, say we want to run a test
case 100 times:

  ./sysctl.sh -c 0001 100

To run a test case only once, for example:

  ./sysctl.sh -s 0002

The default settings are specified at the top of sysctl.sh.

Link: http://lkml.kernel.org/r/20170630224431.17374-3-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 tools/testing/selftests/sysctl/Makefile         |   3 +-
 tools/testing/selftests/sysctl/common_tests     | 131 -------
 tools/testing/selftests/sysctl/run_numerictests |  10 -
 tools/testing/selftests/sysctl/run_stringtests  |  77 ----
 tools/testing/selftests/sysctl/sysctl.sh        | 494 ++++++++++++++++++++++++
 5 files changed, 495 insertions(+), 220 deletions(-)
 delete mode 100644 tools/testing/selftests/sysctl/common_tests
 delete mode 100755 tools/testing/selftests/sysctl/run_numerictests
 delete mode 100755 tools/testing/selftests/sysctl/run_stringtests
 create mode 100644 tools/testing/selftests/sysctl/sysctl.sh

(limited to 'tools')

diff --git a/tools/testing/selftests/sysctl/Makefile b/tools/testing/selftests/sysctl/Makefile
index b3c33e071f10..95c320b354e8 100644
--- a/tools/testing/selftests/sysctl/Makefile
+++ b/tools/testing/selftests/sysctl/Makefile
@@ -4,8 +4,7 @@
 # No binaries, but make sure arg-less "make" doesn't trigger "run_tests".
 all:
 
-TEST_PROGS := run_numerictests run_stringtests
-TEST_FILES := common_tests
+TEST_PROGS := sysctl.sh
 
 include ../lib.mk
 
diff --git a/tools/testing/selftests/sysctl/common_tests b/tools/testing/selftests/sysctl/common_tests
deleted file mode 100644
index b6862322962f..000000000000
--- a/tools/testing/selftests/sysctl/common_tests
+++ /dev/null
@@ -1,131 +0,0 @@
-#!/bin/sh
-
-TEST_FILE=$(mktemp)
-
-echo "== Testing sysctl behavior against ${TARGET} =="
-
-set_orig()
-{
-	echo "${ORIG}" > "${TARGET}"
-}
-
-set_test()
-{
-	echo "${TEST_STR}" > "${TARGET}"
-}
-
-verify()
-{
-	local seen
-	seen=$(cat "$1")
-	if [ "${seen}" != "${TEST_STR}" ]; then
-		return 1
-	fi
-	return 0
-}
-
-exit_test()
-{
-	if [ ! -z ${old_strict} ]; then
-		echo ${old_strict} > ${WRITES_STRICT}
-	fi
-	exit $rc
-}
-
-trap 'set_orig; rm -f "${TEST_FILE}"' EXIT
-
-rc=0
-
-echo -n "Writing test file ... "
-echo "${TEST_STR}" > "${TEST_FILE}"
-if ! verify "${TEST_FILE}"; then
-	echo "FAIL" >&2
-	exit 1
-else
-	echo "ok"
-fi
-
-echo -n "Checking sysctl is not set to test value ... "
-if verify "${TARGET}"; then
-	echo "FAIL" >&2
-	exit 1
-else
-	echo "ok"
-fi
-
-echo -n "Writing sysctl from shell ... "
-set_test
-if ! verify "${TARGET}"; then
-	echo "FAIL" >&2
-	exit 1
-else
-	echo "ok"
-fi
-
-echo -n "Resetting sysctl to original value ... "
-set_orig
-if verify "${TARGET}"; then
-	echo "FAIL" >&2
-	exit 1
-else
-	echo "ok"
-fi
-
-echo -n "Checking write strict setting ... "
-WRITES_STRICT="${SYSCTL}/kernel/sysctl_writes_strict"
-if [ ! -e ${WRITES_STRICT} ]; then
-	echo "FAIL, but skip in case of old kernel" >&2
-else
-	old_strict=$(cat ${WRITES_STRICT})
-	if [ "$old_strict" = "1" ]; then
-		echo "ok"
-	else
-		echo "FAIL, strict value is 0 but force to 1 to continue" >&2
-		echo "1" > ${WRITES_STRICT}
-	fi
-fi
-
-# Now that we've validated the sanity of "set_test" and "set_orig",
-# we can use those functions to set starting states before running
-# specific behavioral tests.
-
-echo -n "Writing entire sysctl in single write ... "
-set_orig
-dd if="${TEST_FILE}" of="${TARGET}" bs=4096 2>/dev/null
-if ! verify "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Writing middle of sysctl after synchronized seek ... "
-set_test
-dd if="${TEST_FILE}" of="${TARGET}" bs=1 seek=1 skip=1 2>/dev/null
-if ! verify "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Writing beyond end of sysctl ... "
-set_orig
-dd if="${TEST_FILE}" of="${TARGET}" bs=20 seek=2 2>/dev/null
-if verify "${TARGET}"; then
-        echo "FAIL" >&2
-        rc=1
-else
-        echo "ok"
-fi
-
-echo -n "Writing sysctl with multiple long writes ... "
-set_orig
-(perl -e 'print "A" x 50;'; echo "${TEST_STR}") | \
-	dd of="${TARGET}" bs=50 2>/dev/null
-if verify "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
diff --git a/tools/testing/selftests/sysctl/run_numerictests b/tools/testing/selftests/sysctl/run_numerictests
deleted file mode 100755
index c375ce0f4c15..000000000000
--- a/tools/testing/selftests/sysctl/run_numerictests
+++ /dev/null
@@ -1,10 +0,0 @@
-#!/bin/sh
-
-SYSCTL="/proc/sys/debug/test_sysctl/"
-TARGET="${SYSCTL}/int_0001"
-ORIG=$(cat "${TARGET}")
-TEST_STR=$(( $ORIG + 1 ))
-
-. ./common_tests
-
-exit_test
diff --git a/tools/testing/selftests/sysctl/run_stringtests b/tools/testing/selftests/sysctl/run_stringtests
deleted file mode 100755
index a6f2618afeaa..000000000000
--- a/tools/testing/selftests/sysctl/run_stringtests
+++ /dev/null
@@ -1,77 +0,0 @@
-#!/bin/sh
-
-SYSCTL="/proc/sys/debug/test_sysctl/"
-TARGET="${SYSCTL}/string_0001"
-ORIG=$(cat "${TARGET}")
-TEST_STR="Testing sysctl"
-
-. ./common_tests
-
-# Only string sysctls support seeking/appending.
-MAXLEN=65
-
-echo -n "Writing entire sysctl in short writes ... "
-set_orig
-dd if="${TEST_FILE}" of="${TARGET}" bs=1 2>/dev/null
-if ! verify "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Writing middle of sysctl after unsynchronized seek ... "
-set_test
-dd if="${TEST_FILE}" of="${TARGET}" bs=1 seek=1 2>/dev/null
-if verify "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Checking sysctl maxlen is at least $MAXLEN ... "
-set_orig
-perl -e 'print "A" x ('"${MAXLEN}"'-2), "B";' | \
-	dd of="${TARGET}" bs="${MAXLEN}" 2>/dev/null
-if ! grep -q B "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Checking sysctl keeps original string on overflow append ... "
-set_orig
-perl -e 'print "A" x ('"${MAXLEN}"'-1), "B";' | \
-	dd of="${TARGET}" bs=$(( MAXLEN - 1 )) 2>/dev/null
-if grep -q B "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Checking sysctl stays NULL terminated on write ... "
-set_orig
-perl -e 'print "A" x ('"${MAXLEN}"'-1), "B";' | \
-	dd of="${TARGET}" bs="${MAXLEN}" 2>/dev/null
-if grep -q B "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Checking sysctl stays NULL terminated on overwrite ... "
-set_orig
-perl -e 'print "A" x ('"${MAXLEN}"'-1), "BB";' | \
-	dd of="${TARGET}" bs=$(( $MAXLEN + 1 )) 2>/dev/null
-if grep -q B "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-exit_test
diff --git a/tools/testing/selftests/sysctl/sysctl.sh b/tools/testing/selftests/sysctl/sysctl.sh
new file mode 100644
index 000000000000..cbe1345d7c1d
--- /dev/null
+++ b/tools/testing/selftests/sysctl/sysctl.sh
@@ -0,0 +1,494 @@
+#!/bin/bash
+# Copyright (C) 2017 Luis R. Rodriguez <mcgrof@kernel.org>
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the Free
+# Software Foundation; either version 2 of the License, or at your option any
+# later version; or, when distributed separately from the Linux kernel or
+# when incorporated into other software packages, subject to the following
+# license:
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of copyleft-next (version 0.3.1 or later) as published
+# at http://copyleft-next.org/.
+
+# This performs a series tests against the proc sysctl interface.
+
+TEST_NAME="sysctl"
+TEST_DRIVER="test_${TEST_NAME}"
+TEST_DIR=$(dirname $0)
+TEST_FILE=$(mktemp)
+
+# This represents
+#
+# TEST_ID:TEST_COUNT:ENABLED
+#
+# TEST_ID: is the test id number
+# TEST_COUNT: number of times we should run the test
+# ENABLED: 1 if enabled, 0 otherwise
+#
+# Once these are enabled please leave them as-is. Write your own test,
+# we have tons of space.
+ALL_TESTS="0001:1:1"
+ALL_TESTS="$ALL_TESTS 0002:1:1"
+
+test_modprobe()
+{
+       if [ ! -d $DIR ]; then
+               echo "$0: $DIR not present" >&2
+               echo "You must have the following enabled in your kernel:" >&2
+               cat $TEST_DIR/config >&2
+               exit 1
+       fi
+}
+
+function allow_user_defaults()
+{
+	if [ -z $DIR ]; then
+		DIR="/sys/module/test_sysctl/"
+	fi
+	if [ -z $DEFAULT_NUM_TESTS ]; then
+		DEFAULT_NUM_TESTS=50
+	fi
+	if [ -z $SYSCTL ]; then
+		SYSCTL="/proc/sys/debug/test_sysctl"
+	fi
+	if [ -z $PROD_SYSCTL ]; then
+		PROD_SYSCTL="/proc/sys"
+	fi
+	if [ -z $WRITES_STRICT ]; then
+		WRITES_STRICT="${PROD_SYSCTL}/kernel/sysctl_writes_strict"
+	fi
+}
+
+function check_production_sysctl_writes_strict()
+{
+	echo -n "Checking production write strict setting ... "
+	if [ ! -e ${WRITES_STRICT} ]; then
+		echo "FAIL, but skip in case of old kernel" >&2
+	else
+		old_strict=$(cat ${WRITES_STRICT})
+		if [ "$old_strict" = "1" ]; then
+			echo "ok"
+		else
+			echo "FAIL, strict value is 0 but force to 1 to continue" >&2
+			echo "1" > ${WRITES_STRICT}
+		fi
+	fi
+}
+
+test_reqs()
+{
+	uid=$(id -u)
+	if [ $uid -ne 0 ]; then
+		echo $msg must be run as root >&2
+		exit 0
+	fi
+
+	if ! which perl 2> /dev/null > /dev/null; then
+		echo "$0: You need perl installed"
+		exit 1
+	fi
+}
+
+function load_req_mod()
+{
+	trap "test_modprobe" EXIT
+
+	if [ ! -d $DIR ]; then
+		modprobe $TEST_DRIVER
+		if [ $? -ne 0 ]; then
+			exit
+		fi
+	fi
+}
+
+set_orig()
+{
+	if [ ! -z $TARGET ]; then
+		echo "${ORIG}" > "${TARGET}"
+	fi
+}
+
+set_test()
+{
+	echo "${TEST_STR}" > "${TARGET}"
+}
+
+verify()
+{
+	local seen
+	seen=$(cat "$1")
+	if [ "${seen}" != "${TEST_STR}" ]; then
+		return 1
+	fi
+	return 0
+}
+
+test_rc()
+{
+	if [[ $rc != 0 ]]; then
+		echo "Failed test, return value: $rc" >&2
+		exit $rc
+	fi
+}
+
+test_finish()
+{
+	set_orig
+	rm -f "${TEST_FILE}"
+
+	if [ ! -z ${old_strict} ]; then
+		echo ${old_strict} > ${WRITES_STRICT}
+	fi
+	exit $rc
+}
+
+run_numerictests()
+{
+	echo "== Testing sysctl behavior against ${TARGET} =="
+
+	rc=0
+
+	echo -n "Writing test file ... "
+	echo "${TEST_STR}" > "${TEST_FILE}"
+	if ! verify "${TEST_FILE}"; then
+		echo "FAIL" >&2
+		exit 1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Checking sysctl is not set to test value ... "
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		exit 1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Writing sysctl from shell ... "
+	set_test
+	if ! verify "${TARGET}"; then
+		echo "FAIL" >&2
+		exit 1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Resetting sysctl to original value ... "
+	set_orig
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		exit 1
+	else
+		echo "ok"
+	fi
+
+	# Now that we've validated the sanity of "set_test" and "set_orig",
+	# we can use those functions to set starting states before running
+	# specific behavioral tests.
+
+	echo -n "Writing entire sysctl in single write ... "
+	set_orig
+	dd if="${TEST_FILE}" of="${TARGET}" bs=4096 2>/dev/null
+	if ! verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Writing middle of sysctl after synchronized seek ... "
+	set_test
+	dd if="${TEST_FILE}" of="${TARGET}" bs=1 seek=1 skip=1 2>/dev/null
+	if ! verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Writing beyond end of sysctl ... "
+	set_orig
+	dd if="${TEST_FILE}" of="${TARGET}" bs=20 seek=2 2>/dev/null
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Writing sysctl with multiple long writes ... "
+	set_orig
+	(perl -e 'print "A" x 50;'; echo "${TEST_STR}") | \
+		dd of="${TARGET}" bs=50 2>/dev/null
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	test_rc
+}
+
+run_stringtests()
+{
+	echo -n "Writing entire sysctl in short writes ... "
+	set_orig
+	dd if="${TEST_FILE}" of="${TARGET}" bs=1 2>/dev/null
+	if ! verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Writing middle of sysctl after unsynchronized seek ... "
+	set_test
+	dd if="${TEST_FILE}" of="${TARGET}" bs=1 seek=1 2>/dev/null
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Checking sysctl maxlen is at least $MAXLEN ... "
+	set_orig
+	perl -e 'print "A" x ('"${MAXLEN}"'-2), "B";' | \
+		dd of="${TARGET}" bs="${MAXLEN}" 2>/dev/null
+	if ! grep -q B "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Checking sysctl keeps original string on overflow append ... "
+	set_orig
+	perl -e 'print "A" x ('"${MAXLEN}"'-1), "B";' | \
+		dd of="${TARGET}" bs=$(( MAXLEN - 1 )) 2>/dev/null
+	if grep -q B "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Checking sysctl stays NULL terminated on write ... "
+	set_orig
+	perl -e 'print "A" x ('"${MAXLEN}"'-1), "B";' | \
+		dd of="${TARGET}" bs="${MAXLEN}" 2>/dev/null
+	if grep -q B "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	echo -n "Checking sysctl stays NULL terminated on overwrite ... "
+	set_orig
+	perl -e 'print "A" x ('"${MAXLEN}"'-1), "BB";' | \
+		dd of="${TARGET}" bs=$(( $MAXLEN + 1 )) 2>/dev/null
+	if grep -q B "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+
+	test_rc
+}
+
+sysctl_test_0001()
+{
+	TARGET="${SYSCTL}/int_0001"
+	ORIG=$(cat "${TARGET}")
+	TEST_STR=$(( $ORIG + 1 ))
+
+	run_numerictests
+}
+
+sysctl_test_0002()
+{
+	TARGET="${SYSCTL}/string_0001"
+	ORIG=$(cat "${TARGET}")
+	TEST_STR="Testing sysctl"
+	# Only string sysctls support seeking/appending.
+	MAXLEN=65
+
+	run_numerictests
+	run_stringtests
+}
+
+list_tests()
+{
+	echo "Test ID list:"
+	echo
+	echo "TEST_ID x NUM_TEST"
+	echo "TEST_ID:   Test ID"
+	echo "NUM_TESTS: Number of recommended times to run the test"
+	echo
+	echo "0001 x $(get_test_count 0001) - tests proc_dointvec_minmax()"
+	echo "0002 x $(get_test_count 0002) - tests proc_dostring()"
+}
+
+test_reqs
+
+usage()
+{
+	NUM_TESTS=$(grep -o ' ' <<<"$ALL_TESTS" | grep -c .)
+	let NUM_TESTS=$NUM_TESTS+1
+	MAX_TEST=$(printf "%04d\n" $NUM_TESTS)
+	echo "Usage: $0 [ -t <4-number-digit> ] | [ -w <4-number-digit> ] |"
+	echo "		 [ -s <4-number-digit> ] | [ -c <4-number-digit> <test- count>"
+	echo "           [ all ] [ -h | --help ] [ -l ]"
+	echo ""
+	echo "Valid tests: 0001-$MAX_TEST"
+	echo ""
+	echo "    all     Runs all tests (default)"
+	echo "    -t      Run test ID the number amount of times is recommended"
+	echo "    -w      Watch test ID run until it runs into an error"
+	echo "    -c      Run test ID once"
+	echo "    -s      Run test ID x test-count number of times"
+	echo "    -l      List all test ID list"
+	echo " -h|--help  Help"
+	echo
+	echo "If an error every occurs execution will immediately terminate."
+	echo "If you are adding a new test try using -w <test-ID> first to"
+	echo "make sure the test passes a series of tests."
+	echo
+	echo Example uses:
+	echo
+	echo "$TEST_NAME.sh            -- executes all tests"
+	echo "$TEST_NAME.sh -t 0002    -- Executes test ID 0002 number of times is recomended"
+	echo "$TEST_NAME.sh -w 0002    -- Watch test ID 0002 run until an error occurs"
+	echo "$TEST_NAME.sh -s 0002    -- Run test ID 0002 once"
+	echo "$TEST_NAME.sh -c 0002 3  -- Run test ID 0002 three times"
+	echo
+	list_tests
+	exit 1
+}
+
+function test_num()
+{
+	re='^[0-9]+$'
+	if ! [[ $1 =~ $re ]]; then
+		usage
+	fi
+}
+
+function get_test_count()
+{
+	test_num $1
+	TEST_DATA=$(echo $ALL_TESTS | awk '{print $'$1'}')
+	LAST_TWO=${TEST_DATA#*:*}
+	echo ${LAST_TWO%:*}
+}
+
+function get_test_enabled()
+{
+	test_num $1
+	TEST_DATA=$(echo $ALL_TESTS | awk '{print $'$1'}')
+	echo ${TEST_DATA#*:*:}
+}
+
+function run_all_tests()
+{
+	for i in $ALL_TESTS ; do
+		TEST_ID=${i%:*:*}
+		ENABLED=$(get_test_enabled $TEST_ID)
+		TEST_COUNT=$(get_test_count $TEST_ID)
+		if [[ $ENABLED -eq "1" ]]; then
+			test_case $TEST_ID $TEST_COUNT
+		fi
+	done
+}
+
+function watch_log()
+{
+	if [ $# -ne 3 ]; then
+		clear
+	fi
+	date
+	echo "Running test: $2 - run #$1"
+}
+
+function watch_case()
+{
+	i=0
+	while [ 1 ]; do
+
+		if [ $# -eq 1 ]; then
+			test_num $1
+			watch_log $i ${TEST_NAME}_test_$1
+			${TEST_NAME}_test_$1
+		else
+			watch_log $i all
+			run_all_tests
+		fi
+		let i=$i+1
+	done
+}
+
+function test_case()
+{
+	NUM_TESTS=$DEFAULT_NUM_TESTS
+	if [ $# -eq 2 ]; then
+		NUM_TESTS=$2
+	fi
+
+	i=0
+	while [ $i -lt $NUM_TESTS ]; do
+		test_num $1
+		watch_log $i ${TEST_NAME}_test_$1 noclear
+		RUN_TEST=${TEST_NAME}_test_$1
+		$RUN_TEST
+		let i=$i+1
+	done
+}
+
+function parse_args()
+{
+	if [ $# -eq 0 ]; then
+		run_all_tests
+	else
+		if [[ "$1" = "all" ]]; then
+			run_all_tests
+		elif [[ "$1" = "-w" ]]; then
+			shift
+			watch_case $@
+		elif [[ "$1" = "-t" ]]; then
+			shift
+			test_num $1
+			test_case $1 $(get_test_count $1)
+		elif [[ "$1" = "-c" ]]; then
+			shift
+			test_num $1
+			test_num $2
+			test_case $1 $2
+		elif [[ "$1" = "-s" ]]; then
+			shift
+			test_case $1 1
+		elif [[ "$1" = "-l" ]]; then
+			list_tests
+		elif [[ "$1" = "-h" || "$1" = "--help" ]]; then
+			usage
+		else
+			usage
+		fi
+	fi
+}
+
+test_reqs
+allow_user_defaults
+check_production_sysctl_writes_strict
+load_req_mod
+
+trap "test_finish" EXIT
+
+parse_args $@
+
+exit 0
-- 
cgit v1.2.3


From 1c0357c846452add7c2c863ec372010e3d2ca943 Mon Sep 17 00:00:00 2001
From: "Luis R. Rodriguez" <mcgrof@kernel.org>
Date: Wed, 12 Jul 2017 14:33:49 -0700
Subject: test_sysctl: test against PAGE_SIZE for int

Add the following tests to ensure we do not regress:

  o Test using a buffer full of space (PAGE_SIZE-1) followed by a
    single digit works

  o Test using a buffer full of spaces (PAGE_SIZE or over) will fail

As tests increase instead of unloading the module and reloading it we
can just do a shell reset_vals() with a reset to values we know are set
at init on the driver.

Link: http://lkml.kernel.org/r/20170630224431.17374-4-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 tools/testing/selftests/sysctl/sysctl.sh | 66 ++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)

(limited to 'tools')

diff --git a/tools/testing/selftests/sysctl/sysctl.sh b/tools/testing/selftests/sysctl/sysctl.sh
index cbe1345d7c1d..6ec807576f7c 100644
--- a/tools/testing/selftests/sysctl/sysctl.sh
+++ b/tools/testing/selftests/sysctl/sysctl.sh
@@ -75,6 +75,13 @@ function check_production_sysctl_writes_strict()
 			echo "1" > ${WRITES_STRICT}
 		fi
 	fi
+
+	if [ -z $PAGE_SIZE ]; then
+		PAGE_SIZE=$(getconf PAGESIZE)
+	fi
+	if [ -z $MAX_DIGITS ]; then
+		MAX_DIGITS=$(($PAGE_SIZE/8))
+	fi
 }
 
 test_reqs()
@@ -89,6 +96,10 @@ test_reqs()
 		echo "$0: You need perl installed"
 		exit 1
 	fi
+	if ! which getconf 2> /dev/null > /dev/null; then
+		echo "$0: You need getconf installed"
+		exit 1
+	fi
 }
 
 function load_req_mod()
@@ -103,6 +114,23 @@ function load_req_mod()
 	fi
 }
 
+reset_vals()
+{
+	VAL=""
+	TRIGGER=$(basename ${TARGET})
+	case "$TRIGGER" in
+		int_0001)
+			VAL="60"
+			;;
+		string_0001)
+			VAL="(none)"
+			;;
+		*)
+			;;
+	esac
+	echo -n $VAL > $TARGET
+}
+
 set_orig()
 {
 	if [ ! -z $TARGET ]; then
@@ -229,7 +257,42 @@ run_numerictests()
 	else
 		echo "ok"
 	fi
+	test_rc
+}
+
+# Your test must accept digits 3 and 4 to use this
+run_limit_digit()
+{
+	echo -n "Checking ignoring spaces up to PAGE_SIZE works on write ..."
+	reset_vals
 
+	LIMIT=$((MAX_DIGITS -1))
+	TEST_STR="3"
+	(perl -e 'print " " x '$LIMIT';'; echo "${TEST_STR}") | \
+		dd of="${TARGET}" 2>/dev/null
+
+	if ! verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+	test_rc
+
+	echo -n "Checking passing PAGE_SIZE of spaces fails on write ..."
+	reset_vals
+
+	LIMIT=$((MAX_DIGITS))
+	TEST_STR="4"
+	(perl -e 'print " " x '$LIMIT';'; echo "${TEST_STR}") | \
+		dd of="${TARGET}" 2>/dev/null
+
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
 	test_rc
 }
 
@@ -305,15 +368,18 @@ run_stringtests()
 sysctl_test_0001()
 {
 	TARGET="${SYSCTL}/int_0001"
+	reset_vals
 	ORIG=$(cat "${TARGET}")
 	TEST_STR=$(( $ORIG + 1 ))
 
 	run_numerictests
+	run_limit_digit
 }
 
 sysctl_test_0002()
 {
 	TARGET="${SYSCTL}/string_0001"
+	reset_vals
 	ORIG=$(cat "${TARGET}")
 	TEST_STR="Testing sysctl"
 	# Only string sysctls support seeking/appending.
-- 
cgit v1.2.3


From eb965eda1cabf26e62afc07a06cdf2fd5aaa2906 Mon Sep 17 00:00:00 2001
From: "Luis R. Rodriguez" <mcgrof@kernel.org>
Date: Wed, 12 Jul 2017 14:33:52 -0700
Subject: test_sysctl: add simple proc_dointvec() case

Test against a simple proc_dointvec() case.  While at it, add a test
against INT_MAX.  Make sure INT_MAX works, and INT_MAX+1 will fail.
Also test negative values work.

Link: http://lkml.kernel.org/r/20170630224431.17374-5-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 tools/testing/selftests/sysctl/sysctl.sh | 62 ++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

(limited to 'tools')

diff --git a/tools/testing/selftests/sysctl/sysctl.sh b/tools/testing/selftests/sysctl/sysctl.sh
index 6ec807576f7c..7ba3fa2bbd54 100644
--- a/tools/testing/selftests/sysctl/sysctl.sh
+++ b/tools/testing/selftests/sysctl/sysctl.sh
@@ -31,6 +31,7 @@ TEST_FILE=$(mktemp)
 # we have tons of space.
 ALL_TESTS="0001:1:1"
 ALL_TESTS="$ALL_TESTS 0002:1:1"
+ALL_TESTS="$ALL_TESTS 0003:1:1"
 
 test_modprobe()
 {
@@ -82,6 +83,9 @@ function check_production_sysctl_writes_strict()
 	if [ -z $MAX_DIGITS ]; then
 		MAX_DIGITS=$(($PAGE_SIZE/8))
 	fi
+	if [ -z $INT_MAX ]; then
+		INT_MAX=$(getconf INT_MAX)
+	fi
 }
 
 test_reqs()
@@ -122,6 +126,9 @@ reset_vals()
 		int_0001)
 			VAL="60"
 			;;
+		int_0002)
+			VAL="1"
+			;;
 		string_0001)
 			VAL="(none)"
 			;;
@@ -296,6 +303,48 @@ run_limit_digit()
 	test_rc
 }
 
+# You are using an int
+run_limit_digit_int()
+{
+	echo -n "Testing INT_MAX works ..."
+	reset_vals
+	TEST_STR="$INT_MAX"
+	echo -n $TEST_STR > $TARGET
+
+	if ! verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+	test_rc
+
+	echo -n "Testing INT_MAX + 1 will fail as expected..."
+	reset_vals
+	let TEST_STR=$INT_MAX+1
+	echo -n $TEST_STR > $TARGET 2> /dev/null
+
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+	test_rc
+
+	echo -n "Testing negative values will work as expected..."
+	reset_vals
+	TEST_STR="-3"
+	echo -n $TEST_STR > $TARGET 2> /dev/null
+	if ! verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+	test_rc
+}
+
 run_stringtests()
 {
 	echo -n "Writing entire sysctl in short writes ... "
@@ -389,6 +438,18 @@ sysctl_test_0002()
 	run_stringtests
 }
 
+sysctl_test_0003()
+{
+	TARGET="${SYSCTL}/int_0002"
+	reset_vals
+	ORIG=$(cat "${TARGET}")
+	TEST_STR=$(( $ORIG + 1 ))
+
+	run_numerictests
+	run_limit_digit
+	run_limit_digit_int
+}
+
 list_tests()
 {
 	echo "Test ID list:"
@@ -399,6 +460,7 @@ list_tests()
 	echo
 	echo "0001 x $(get_test_count 0001) - tests proc_dointvec_minmax()"
 	echo "0002 x $(get_test_count 0002) - tests proc_dostring()"
+	echo "0003 x $(get_test_count 0003) - tests proc_dointvec()"
 }
 
 test_reqs
-- 
cgit v1.2.3


From 2920fad3a5d394b66011c7f35c7b05278354055e Mon Sep 17 00:00:00 2001
From: "Luis R. Rodriguez" <mcgrof@kernel.org>
Date: Wed, 12 Jul 2017 14:33:55 -0700
Subject: test_sysctl: add simple proc_douintvec() case

Test against a simple proc_douintvec() case.  While at it, add a test
against UINT_MAX.  Make sure UINT_MAX works, and UINT_MAX+1 will fail
and that negative values are not accepted.

Link: http://lkml.kernel.org/r/20170630224431.17374-6-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 tools/testing/selftests/sysctl/sysctl.sh | 63 ++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

(limited to 'tools')

diff --git a/tools/testing/selftests/sysctl/sysctl.sh b/tools/testing/selftests/sysctl/sysctl.sh
index 7ba3fa2bbd54..abeef675a884 100644
--- a/tools/testing/selftests/sysctl/sysctl.sh
+++ b/tools/testing/selftests/sysctl/sysctl.sh
@@ -32,6 +32,7 @@ TEST_FILE=$(mktemp)
 ALL_TESTS="0001:1:1"
 ALL_TESTS="$ALL_TESTS 0002:1:1"
 ALL_TESTS="$ALL_TESTS 0003:1:1"
+ALL_TESTS="$ALL_TESTS 0004:1:1"
 
 test_modprobe()
 {
@@ -86,6 +87,9 @@ function check_production_sysctl_writes_strict()
 	if [ -z $INT_MAX ]; then
 		INT_MAX=$(getconf INT_MAX)
 	fi
+	if [ -z $UINT_MAX ]; then
+		UINT_MAX=$(getconf UINT_MAX)
+	fi
 }
 
 test_reqs()
@@ -129,6 +133,9 @@ reset_vals()
 		int_0002)
 			VAL="1"
 			;;
+		uint_0001)
+			VAL="314"
+			;;
 		string_0001)
 			VAL="(none)"
 			;;
@@ -345,6 +352,49 @@ run_limit_digit_int()
 	test_rc
 }
 
+# You are using an unsigned int
+run_limit_digit_uint()
+{
+	echo -n "Testing UINT_MAX works ..."
+	reset_vals
+	TEST_STR="$UINT_MAX"
+	echo -n $TEST_STR > $TARGET
+
+	if ! verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+	test_rc
+
+	echo -n "Testing UINT_MAX + 1 will fail as expected..."
+	reset_vals
+	TEST_STR=$(($UINT_MAX+1))
+	echo -n $TEST_STR > $TARGET 2> /dev/null
+
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+	test_rc
+
+	echo -n "Testing negative values will not work as expected ..."
+	reset_vals
+	TEST_STR="-3"
+	echo -n $TEST_STR > $TARGET 2> /dev/null
+
+	if verify "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+	test_rc
+}
+
 run_stringtests()
 {
 	echo -n "Writing entire sysctl in short writes ... "
@@ -450,6 +500,18 @@ sysctl_test_0003()
 	run_limit_digit_int
 }
 
+sysctl_test_0004()
+{
+	TARGET="${SYSCTL}/uint_0001"
+	reset_vals
+	ORIG=$(cat "${TARGET}")
+	TEST_STR=$(( $ORIG + 1 ))
+
+	run_numerictests
+	run_limit_digit
+	run_limit_digit_uint
+}
+
 list_tests()
 {
 	echo "Test ID list:"
@@ -461,6 +523,7 @@ list_tests()
 	echo "0001 x $(get_test_count 0001) - tests proc_dointvec_minmax()"
 	echo "0002 x $(get_test_count 0002) - tests proc_dostring()"
 	echo "0003 x $(get_test_count 0003) - tests proc_dointvec()"
+	echo "0004 x $(get_test_count 0004) - tests proc_douintvec()"
 }
 
 test_reqs
-- 
cgit v1.2.3


From 7c43a657a4beadeb6d2fe1a00732261e313a807f Mon Sep 17 00:00:00 2001
From: "Luis R. Rodriguez" <mcgrof@kernel.org>
Date: Wed, 12 Jul 2017 14:33:58 -0700
Subject: test_sysctl: test against int proc_dointvec() array support

Add a few initial respective tests for an array:

  o Echoing values separated by spaces works
  o Echoing only first elements will set first elements
  o Confirm PAGE_SIZE limit still applies even if an array is used

Link: http://lkml.kernel.org/r/20170630224431.17374-7-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 tools/testing/selftests/sysctl/sysctl.sh | 89 ++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)

(limited to 'tools')

diff --git a/tools/testing/selftests/sysctl/sysctl.sh b/tools/testing/selftests/sysctl/sysctl.sh
index abeef675a884..ec232c3cfcaa 100644
--- a/tools/testing/selftests/sysctl/sysctl.sh
+++ b/tools/testing/selftests/sysctl/sysctl.sh
@@ -33,6 +33,7 @@ ALL_TESTS="0001:1:1"
 ALL_TESTS="$ALL_TESTS 0002:1:1"
 ALL_TESTS="$ALL_TESTS 0003:1:1"
 ALL_TESTS="$ALL_TESTS 0004:1:1"
+ALL_TESTS="$ALL_TESTS 0005:3:1"
 
 test_modprobe()
 {
@@ -108,6 +109,10 @@ test_reqs()
 		echo "$0: You need getconf installed"
 		exit 1
 	fi
+	if ! which diff 2> /dev/null > /dev/null; then
+		echo "$0: You need diff installed"
+		exit 1
+	fi
 }
 
 function load_req_mod()
@@ -167,6 +172,12 @@ verify()
 	return 0
 }
 
+verify_diff_w()
+{
+	echo "$TEST_STR" | diff -q -w -u - $1
+	return $?
+}
+
 test_rc()
 {
 	if [[ $rc != 0 ]]; then
@@ -352,6 +363,74 @@ run_limit_digit_int()
 	test_rc
 }
 
+# You used an int array
+run_limit_digit_int_array()
+{
+	echo -n "Testing array works as expected ... "
+	TEST_STR="4 3 2 1"
+	echo -n $TEST_STR > $TARGET
+
+	if ! verify_diff_w "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+	test_rc
+
+	echo -n "Testing skipping trailing array elements works ... "
+	# Do not reset_vals, carry on the values from the last test.
+	# If we only echo in two digits the last two are left intact
+	TEST_STR="100 101"
+	echo -n $TEST_STR > $TARGET
+	# After we echo in, to help diff we need to set on TEST_STR what
+	# we expect the result to be.
+	TEST_STR="100 101 2 1"
+
+	if ! verify_diff_w "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+	test_rc
+
+	echo -n "Testing PAGE_SIZE limit on array works ... "
+	# Do not reset_vals, carry on the values from the last test.
+	# Even if you use an int array, you are still restricted to
+	# MAX_DIGITS, this is a known limitation. Test limit works.
+	LIMIT=$((MAX_DIGITS -1))
+	TEST_STR="9"
+	(perl -e 'print " " x '$LIMIT';'; echo "${TEST_STR}") | \
+		dd of="${TARGET}" 2>/dev/null
+
+	TEST_STR="9 101 2 1"
+	if ! verify_diff_w "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+	test_rc
+
+	echo -n "Testing exceeding PAGE_SIZE limit fails as expected ... "
+	# Do not reset_vals, carry on the values from the last test.
+	# Now go over limit.
+	LIMIT=$((MAX_DIGITS))
+	TEST_STR="7"
+	(perl -e 'print " " x '$LIMIT';'; echo "${TEST_STR}") | \
+		dd of="${TARGET}" 2>/dev/null
+
+	TEST_STR="7 101 2 1"
+	if verify_diff_w "${TARGET}"; then
+		echo "FAIL" >&2
+		rc=1
+	else
+		echo "ok"
+	fi
+	test_rc
+}
+
 # You are using an unsigned int
 run_limit_digit_uint()
 {
@@ -512,6 +591,15 @@ sysctl_test_0004()
 	run_limit_digit_uint
 }
 
+sysctl_test_0005()
+{
+	TARGET="${SYSCTL}/int_0003"
+	reset_vals
+	ORIG=$(cat "${TARGET}")
+
+	run_limit_digit_int_array
+}
+
 list_tests()
 {
 	echo "Test ID list:"
@@ -524,6 +612,7 @@ list_tests()
 	echo "0002 x $(get_test_count 0002) - tests proc_dostring()"
 	echo "0003 x $(get_test_count 0003) - tests proc_dointvec()"
 	echo "0004 x $(get_test_count 0004) - tests proc_douintvec()"
+	echo "0005 x $(get_test_count 0005) - tests proc_douintvec() array"
 }
 
 test_reqs
-- 
cgit v1.2.3


From dcda9b04713c3f6ff0875652924844fae28286ea Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.com>
Date: Wed, 12 Jul 2017 14:36:45 -0700
Subject: mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more
 useful semantic

__GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to
the page allocator.  This has been true but only for allocations
requests larger than PAGE_ALLOC_COSTLY_ORDER.  It has been always
ignored for smaller sizes.  This is a bit unfortunate because there is
no way to express the same semantic for those requests and they are
considered too important to fail so they might end up looping in the
page allocator for ever, similarly to GFP_NOFAIL requests.

Now that the whole tree has been cleaned up and accidental or misled
usage of __GFP_REPEAT flag has been removed for !costly requests we can
give the original flag a better name and more importantly a more useful
semantic.  Let's rename it to __GFP_RETRY_MAYFAIL which tells the user
that the allocator would try really hard but there is no promise of a
success.  This will work independent of the order and overrides the
default allocator behavior.  Page allocator users have several levels of
guarantee vs.  cost options (take GFP_KERNEL as an example)

 - GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_
   attempt to free memory at all. The most light weight mode which even
   doesn't kick the background reclaim. Should be used carefully because
   it might deplete the memory and the next user might hit the more
   aggressive reclaim

 - GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic
   allocation without any attempt to free memory from the current
   context but can wake kswapd to reclaim memory if the zone is below
   the low watermark. Can be used from either atomic contexts or when
   the request is a performance optimization and there is another
   fallback for a slow path.

 - (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) -
   non sleeping allocation with an expensive fallback so it can access
   some portion of memory reserves. Usually used from interrupt/bh
   context with an expensive slow path fallback.

 - GFP_KERNEL - both background and direct reclaim are allowed and the
   _default_ page allocator behavior is used. That means that !costly
   allocation requests are basically nofail but there is no guarantee of
   that behavior so failures have to be checked properly by callers
   (e.g. OOM killer victim is allowed to fail currently).

 - GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior
   and all allocation requests fail early rather than cause disruptive
   reclaim (one round of reclaim in this implementation). The OOM killer
   is not invoked.

 - GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator
   behavior and all allocation requests try really hard. The request
   will fail if the reclaim cannot make any progress. The OOM killer
   won't be triggered.

 - GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior
   and all allocation requests will loop endlessly until they succeed.
   This might be really dangerous especially for larger orders.

Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL
because they already had their semantic.  No new users are added.
__alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if
there is no progress and we have already passed the OOM point.

This means that all the reclaim opportunities have been exhausted except
the most disruptive one (the OOM killer) and a user defined fallback
behavior is more sensible than keep retrying in the page allocator.

[akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c]
[mhocko@suse.com: semantic fix]
  Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz
[mhocko@kernel.org: address other thing spotted by Vlastimil]
  Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alex Belits <alex.belits@cavium.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: NeilBrown <neilb@suse.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 tools/perf/builtin-kmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'tools')

diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index 0a8a1c45af87..a1497c516d85 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -643,7 +643,7 @@ static const struct {
 	{ "__GFP_FS",			"F" },
 	{ "__GFP_COLD",			"CO" },
 	{ "__GFP_NOWARN",		"NWR" },
-	{ "__GFP_REPEAT",		"R" },
+	{ "__GFP_RETRY_MAYFAIL",	"R" },
 	{ "__GFP_NOFAIL",		"NF" },
 	{ "__GFP_NORETRY",		"NR" },
 	{ "__GFP_COMP",			"C" },
-- 
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