From: Luis Chamberlain <mcg...@kernel.org>

The "odd" 256 value was just an issue with the umh never
wrapping it around with WEXITSTATUS() for us. Now that it
does that, we can use a sane value / name for the selftest,
and this is no longer a oddity.

We add a way to detect this for older kernels, and support
the old return value for kernel code where it was given.

This never affected userspace.

Reported-by: Tiezhu Yang <yangtie...@loongson.cn>
Signed-off-by: Luis Chamberlain <mcg...@kernel.org>
---
 tools/testing/selftests/kmod/kmod.sh | 46 +++++++++++++++++++++++-----
 1 file changed, 39 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/kmod/kmod.sh 
b/tools/testing/selftests/kmod/kmod.sh
index da60c3bd4f23..df7b21d8561c 100755
--- a/tools/testing/selftests/kmod/kmod.sh
+++ b/tools/testing/selftests/kmod/kmod.sh
@@ -64,6 +64,8 @@ ALL_TESTS="$ALL_TESTS 0009:150:1"
 ALL_TESTS="$ALL_TESTS 0010:1:1"
 ALL_TESTS="$ALL_TESTS 0011:1:1"
 
+MODULE_NOT_FOUND="FAILURE"
+
 # Kselftest framework requirement - SKIP code is 4.
 ksft_skip=4
 
@@ -155,14 +157,19 @@ test_finish()
        echo "Test completed"
 }
 
+# OLD_FAILURE is just because the old kernel umh never wrapped
+# the error with WEXITSTATUS(). Now that it does it, we get the
+# appropriate actual value from userspace observed in-kernel.
+
+# We keep the old mapping to ensure this script keeps working
+# with older kernels.
 errno_name_to_val()
 {
        case "$1" in
-       # kmod calls modprobe and upon of a module not found
-       # modprobe returns just 1... However in the kernel we
-       # *sometimes* see 256...
-       MODULE_NOT_FOUND)
+       OLD_FAILURE)
                echo 256;;
+       FAILURE)
+               echo 1;;
        SUCCESS)
                echo 0;;
        -EPERM)
@@ -181,7 +188,9 @@ errno_name_to_val()
 errno_val_to_name()
        case "$1" in
        256)
-               echo MODULE_NOT_FOUND;;
+               echo OLD_FAILURE;;
+       1)
+               echo FAILURE;;
        0)
                echo SUCCESS;;
        -1)
@@ -335,6 +344,28 @@ kmod_defaults_fs()
        config_set_test_case_fs
 }
 
+check_umh()
+{
+       NAME=''
+
+       kmod_defaults_driver
+       config_num_threads 1
+       printf '\0' >"$DIR"/config_test_driver
+       config_trigger ${FUNCNAME[0]}
+       RC=$(config_get_test_result)
+       if [[ "$RC" == "256" ]]; then
+               MODULE_NOT_FOUND="OLD_FAILURE"
+               echo "check_umh: you have and old umh which didn't wrap errors"
+               echo "           with WEXITSTATUS(). This is OK!"
+       elif [[ "$RC" != "1" ]]; then
+               echo "check_umh: Unexpected return value with no modprobe 
argument: $RC"
+               exit
+       else
+               echo "check_umh: You have a new umh which wraps erros with"
+               echo "           WEXITSTATUS(). This is OK!"
+       fi
+}
+
 kmod_test_0001_driver()
 {
        NAME='\000'
@@ -343,7 +374,7 @@ kmod_test_0001_driver()
        config_num_threads 1
        printf $NAME >"$DIR"/config_test_driver
        config_trigger ${FUNCNAME[0]}
-       config_expect_result ${FUNCNAME[0]} MODULE_NOT_FOUND
+       config_expect_result ${FUNCNAME[0]} $MODULE_NOT_FOUND
 }
 
 kmod_test_0001_fs()
@@ -371,7 +402,7 @@ kmod_test_0002_driver()
        config_set_driver $NAME
        config_num_threads 1
        config_trigger ${FUNCNAME[0]}
-       config_expect_result ${FUNCNAME[0]} MODULE_NOT_FOUND
+       config_expect_result ${FUNCNAME[0]} $MODULE_NOT_FOUND
 }
 
 kmod_test_0002_fs()
@@ -648,6 +679,7 @@ load_req_mod
 MODPROBE=$(</proc/sys/kernel/modprobe)
 trap "test_finish" EXIT
 
+check_umh
 parse_args $@
 
 exit 0
-- 
2.26.2

Reply via email to