[PATCH v2 3/6] test_sysctl: test against PAGE_SIZE for int

From: Luis R. Rodriguez
Date: Fri Jun 30 2017 - 18:44:43 EST


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.

Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
---
tools/testing/selftests/sysctl/sysctl.sh | 66 ++++++++++++++++++++++++++++++++
1 file changed, 66 insertions(+)

diff --git a/tools/testing/selftests/sysctl/sysctl.sh b/tools/testing/selftests/sysctl/sysctl.sh
index cbe1345d7c1d..6ec807576f7c 100755
--- 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.
--
2.11.0