tests: shell: auto-run kmemleak if its available

On my test vm a full scan takes almost 5s. As this would slowdown
the test runs too much, only run them every couple of tests.

This allows to detect when there is a leak reported at the
end of the script, and it allows to narrow down the test
case/group that triggers the issue.

Add new -K flag to force kmemleak runs after each test if its
available, this can then be used to find the exact test case.

Signed-off-by: Florian Westphal <fw@strlen.de>

diff --git a/tests/shell/run-tests.sh b/tests/shell/run-tests.sh
index 1a69987598314f7636437b7d8d13ac8124109933..b66ef4fa4d1f31ffed7926e15ffc5906fd899af1 100755 (executable)
--- a/tests/shell/run-tests.sh
+++ b/tests/shell/run-tests.sh
@@ -74,6 +74,11 @@ if [ "$1" == "-V" ] ; then
        shift
 fi
 
+if [ "$1" == "-K" ]; then
+       KMEMLEAK=y
+       shift
+fi
+
 for arg in "$@"; do
        SINGLE+=" $arg"
        VERBOSE=y
@@ -163,7 +168,46 @@ check_taint()
        read taint_now < /proc/sys/kernel/tainted
        if [ $taint -ne $taint_now ] ; then
                msg_warn "[FAILED]      kernel is tainted: $taint  -> $taint_now"
-               ((failed++))
+       fi
+}
+
+kmem_runs=0
+kmemleak_found=0
+
+check_kmemleak_force()
+{
+       test -f /sys/kernel/debug/kmemleak || return 0
+
+       echo scan > /sys/kernel/debug/kmemleak
+
+       lines=$(grep "unreferenced object" /sys/kernel/debug/kmemleak | wc -l)
+       if [ $lines -ne $kmemleak_found ];then
+               msg_warn "[FAILED]      kmemleak detected $lines memory leaks"
+               kmemleak_found=$lines
+       fi
+
+       if [ $lines -ne 0 ];then
+               return 1
+       fi
+
+       return 0
+}
+
+check_kmemleak()
+{
+       test -f /sys/kernel/debug/kmemleak || return
+
+       if [ "$KMEMLEAK" == "y" ] ; then
+               check_kmemleak_force
+               return
+       fi
+
+       kmem_runs=$((kmem_runs + 1))
+       if [ $((kmem_runs % 30)) -eq 0 ]; then
+               # scan slows tests down quite a bit, hence
+               # do this only for every 30th test file by
+               # default.
+               check_kmemleak_force
        fi
 }
 
@@ -218,9 +262,19 @@ do
        fi
 
        check_taint
+       check_kmemleak
 done
 
 echo ""
+
+# kmemleak may report suspected leaks
+# that get free'd after all, so always do
+# a check after all test cases
+# have completed and reset the counter
+# so another warning gets emitted.
+kmemleak_found=0
+check_kmemleak_force
+
 msg_info "results: [OK] $ok [FAILED] $failed [TOTAL] $((ok+failed))"
 
 kernel_cleanup