merge_config.sh: Check error codes from make

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 <[email protected]>

Reported-by Guillaume Tucker <[email protected]>

Signed-off-by Mark Brown <[email protected]>

---

 scripts/kconfig/merge_config.sh | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

scripts/kconfig/merge_config.sh +5 -6

index d924c51d28b7..bec246719aea 100755
@@ -13,12 +13,12 @@
 #  Copyright (c) 2009-2010 Wind River Systems, Inc.
 #  Copyright 2011 Linaro
 
+set -e
+
 clean_up() {
        rm -f $TMP_FILE
        rm -f $MERGE_FILE
-       exit
 }
-trap clean_up HUP INT TERM
 
 usage() {
        echo "Usage: $0 [OPTIONS] [CONFIG [...]]"

@@ -110,6 +110,9 @@ TMP_FILE=$(mktemp ./.tmp.config.XXXXXXXXXX)
 MERGE_FILE=$(mktemp ./.merge_tmp.config.XXXXXXXXXX)
 
 echo "Using $INITFILE as base"
+
+trap clean_up EXIT
+
 cat $INITFILE > $TMP_FILE
 
 # Merge files, printing warnings on overridden values

@@ -155,7 +158,6 @@ if [ "$RUNMAKE" = "false" ]; then
        echo "#"
        echo "# merged configuration written to $KCONFIG_CONFIG (needs make)"
        echo "#"
-       clean_up
        exit
 fi
 

@@ -185,5 +187,3 @@ for CFG in $(sed -n -e "$SED_CONFIG_EXP1" -e "$SED_CONFIG_EXP2" $TMP_FILE); do
                echo ""
        fi
 done
-
-clean_up
--

2.20.1

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 <[email protected]>

Reported-by Guillaume Tucker <[email protected]>

Signed-off-by Mark Brown <[email protected]>

---

Quoted 6 lines · Mark Brown

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.

Quoted 6 lines

This implementation was suggested by Yamada-san.

Suggested-by Masahiro Yamada <[email protected]>

Reported-by Guillaume Tucker <[email protected]>

Signed-off-by Mark Brown <[email protected]>

---

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 ...

scripts/kconfig/merge_config.sh +1 -1

index bec246719aea..63c8565206a4 100755
@@ -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.

If the intent is to catch errors returned by make, then one simple fix would be ...