From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Refactor the kmemleak code to work correctly with sections. This
requires changing the location of the "is kmemleak enabled?" flag to use
/tmp instead of RESULT_BASE, scanning for leaks after every test, and
clarifying which functions get used when.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
README | 2 ++
check | 7 +++++--
common/rc | 32 ++++++++++++++++++++++----------
3 files changed, 29 insertions(+), 12 deletions(-)
diff --git a/README b/README
index 73f057f3..6e9aa34d 100644
--- a/README
+++ b/README
@@ -99,6 +99,8 @@ Preparing system for tests:
that relevant results are compared. For example 'spinningrust'
for configurations that use spinning disks and 'nvme' for tests
using nvme drives.
+ - set USE_KMEMLEAK=yes to scan for memory leaks in the kernel
+ after every test, if the kernel supports kmemleak.
- or add a case to the switch in common/config assigning
these variables based on the hostname of your test
diff --git a/check b/check
index 77a06b00..20e95302 100755
--- a/check
+++ b/check
@@ -496,7 +496,7 @@ _expunge_test()
return 0
}
-_init_kmemleak
+_detect_kmemleak
_prepare_test_list
if $OPTIONS_HAVE_SECTIONS; then
@@ -771,9 +771,12 @@ for section in $HOST_OPTIONS_SECTIONS; do
# and log messages that shouldn't be there.
_check_filesystems
_check_dmesg || err=true
- _check_kmemleak || err=true
fi
+ # Scan for memory leaks after every test so that associating
+ # a leak to a particular test will be as accurate as possible.
+ _check_kmemleak || err=true
+
# test ends after all checks are done.
$timestamp && _timestamp
stop=`_wallclock`
diff --git a/common/rc b/common/rc
index b8ed1776..ab468adf 100644
--- a/common/rc
+++ b/common/rc
@@ -3500,7 +3500,7 @@ _check_dmesg()
# capture the kmemleak report
_capture_kmemleak()
{
- local kern_knob="${DEBUGFS_MNT}/kmemleak"
+ local kern_knob="$DEBUGFS_MNT/kmemleak"
local leak_file="$1"
# Tell the kernel to scan for memory leaks. Apparently the write
@@ -3521,17 +3521,20 @@ ENDL
echo "clear" > "$kern_knob"
}
-# set up kmemleak
-_init_kmemleak()
+# Figure out if the running kernel supports kmemleak; if it does, clear out
+# anything that leaked before we even started testing. The leak checker only
+# needs to be primed like this once per ./check invocation.
+_detect_kmemleak()
{
- local kern_knob="${DEBUGFS_MNT}/kmemleak"
+ local kern_knob="$DEBUGFS_MNT/kmemleak"
+ KMEMLEAK_CHECK_FILE="/tmp/check_kmemleak"
# Since kernel v4.19-rc3, the kmemleak knob exists even if kmemleak is
# disabled, but returns EBUSY on write. So instead of relying on
# existance of writable knob file, we use a test file to indicate that
# _check_kmemleak() is enabled only if we actually managed to write to
# the knob file.
- rm -f ${RESULT_BASE}/check_kmemleak
+ rm -f "$KMEMLEAK_CHECK_FILE"
if [ ! -w "$kern_knob" ]; then
return 0
@@ -3541,17 +3544,26 @@ _init_kmemleak()
# then dump all the leaks recorded so far.
if echo "scan=off" > "$kern_knob" 2>/dev/null; then
_capture_kmemleak /dev/null
- touch ${RESULT_BASE}/check_kmemleak
+ touch "$KMEMLEAK_CHECK_FILE"
fi
}
-# check kmemleak log
+# Kick the kmemleak checker to scan for leaks. Background leak scan mode is
+# not enabled, so we must call the kernel to ask for a scan and deal with the
+# results appropriately. This we do after every test completes, whether or not
+# it was successful.
_check_kmemleak()
{
- local kern_knob="${DEBUGFS_MNT}/kmemleak"
- local leak_file="${seqres}.kmemleak"
+ local kern_knob="$DEBUGFS_MNT/kmemleak"
+ local leak_file="$seqres.kmemleak"
- if [ ! -f ${RESULT_BASE}/check_kmemleak ]; then
+ if [ ! -f "$KMEMLEAK_CHECK_FILE" ]; then
+ return 0
+ fi
+
+ # Not enabled, so discard any report of leaks found.
+ if [ "$USE_KMEMLEAK" != "yes" ]; then
+ _capture_kmemleak /dev/null
return 0
fi
