On 19/08/2019 21:06, Mark Brown wrote:
> When we execute make after merging the configurations we ignore any
> errors it produces causing whatever is running merge_config.sh to be
> unaware of any failures. This issue was noticed by Guillaume Tucker
> while looking at problems with testing of clang only builds in KernelCI
> which caused Kbuild to be unable to find a working host compiler.
>
> This implementation was suggested by Yamada-san.
>
> Suggested-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> Reported-by: Guillaume Tucker <guillaume.tucker@xxxxxxxxxxxxx>
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
> ---
I have noticed some recent build failures on -next and the bisect is
pointing to this commit. I have been looking at why this commit is
making the builds fail and I see a few different things going on ...
1. By using 'set -e', if grep fails to find a kconfig option in the
resulting config file, then script exits silently without reporting
which option it failed to find. Hence, it is unclear what triggered
the failure. This may happen when options are being disabled.
2. If an option is disabled by the config fragment that happens to be a
parent of other kconfig options, then although the parent and
children are disabled correctly, the script may fail because it no
longer finds the children in the resulting config file. A specific
example, here is CONFIG_NFS_V4. We disable this option due to
issues with some host machines we use, and disabling this also
disables CONFIG_NFS_V4_1 and CONFIG_NFS_V4_2. Now if all 3 of these
options are enabled by default in the base config file, such as the
case in the ARM64 defconfig, then disabling CONFIG_NFS_V4 in the
config fragment causes merge_config.sh to fail because
CONFIG_NFS_V4_1 and CONFIG_NFS_V4_2 are not defined at all in
the resulting config. This causes grep to fail to find these and
hence causes the script to terminate. In the resulting config file we
just have '# CONFIG_NFS_V4 is not set'. I am not sure if there is an
easy way to determine if a missing config option is legitimate or
not.
A simple way to test the above is ...
$ export ARCH=arm64
$ echo "CONFIG_NFS_V4=n" > kfrag
$ ./scripts/kconfig/merge_config.sh arch/arm64/configs/defconfig kfrag
If the intent is to catch errors returned by make, then one simple fix would be ...
diff --git a/scripts/kconfig/merge_config.sh b/scripts/kconfig/merge_config.sh
index bec246719aea..63c8565206a4 100755
--- a/scripts/kconfig/merge_config.sh
+++ b/scripts/kconfig/merge_config.sh
@@ -179,7 +179,7 @@ make KCONFIG_ALLCONFIG=$TMP_FILE $OUTPUT_ARG $ALLTARGET
for CFG in $(sed -n -e "$SED_CONFIG_EXP1" -e "$SED_CONFIG_EXP2" $TMP_FILE); do
REQUESTED_VAL=$(grep -w -e "$CFG" $TMP_FILE)
- ACTUAL_VAL=$(grep -w -e "$CFG" "$KCONFIG_CONFIG")
+ ACTUAL_VAL=$(grep -w -e "$CFG" "$KCONFIG_CONFIG" || true)
if [ "x$REQUESTED_VAL" != "x$ACTUAL_VAL" ] ; then
echo "Value requested for $CFG not in final .config"
echo "Requested value: $REQUESTED_VAL"
I have been using merge_config.sh to enable and disable various options
we need for testing for sometime now and so would hope I am not doing
anything out of the ordinary here.
Let me know your thoughts.
Cheers
Jon
--
nvpublic
