Am 07.08.25 um 09:22 schrieb Dan Carpenter:
On Thu, Aug 07, 2025 at 08:34:09AM +0200, Stefan Metzmacher wrote:
Am 06.08.25 um 16:39 schrieb Dan Carpenter:
On Wed, Aug 06, 2025 at 04:17:41PM +0200, Stefan Metzmacher wrote:
What was the test that triggered the problem?
Or did you only noticed it by looking at the code?
This was a Smatch static checker warning. You need to have the cross
function DB to detect it.
Ok, I'll try to integrate it into my build flow...
Does it replace sparse or does it run in addition?
In addition. I find the Sparse endianness checks especially useful.
If it replaces sparse I guess a small script would
run them both?
$ cat mychecker.sh:
#!/bin/bash
set -e
sparse $@
smatch $@
And maybe all others from
https://gautammenghani.com/linux,/c/2022/05/19/static-analysis-tools-linux-kernel.html
I'm using this now:
This seems to work for me now:
$ cat custom-checker.sh
#!/bin/bash
set -e
which sparse > /dev/null 2>&1 && {
sparse -Winit-cstring -Wsparse-error -fdiagnostic-prefix=SPARSE $@
}
which smatch > /dev/null 2>&1 && {
smatch -p=kernel --pedantic --succeed $@
}
$ cat build-fs-smb.sh
#!/bin/bash
#
set -ueo pipefail
make modules_prepare
make -j16 M=fs/smb CF=-D__CHECK_ENDIAN__ W=1ce C=1 KBUILD_MODPOST_WARN=1 KCFLAGS="-Wfatal-errors" CHECK="$(pwd)/custom-checker.sh" $@ 2>&1 | tee build-fs-smb.out
cat build-fs-smb.out | grep -v 'parse error: Function too hairy' | grep -q 'error:' || {
rm build-fs-smb.out
exit 0
}
echo ""
echo "BUILD-ERRORS:"
cat build-fs-smb.out | grep -v 'parse error: Function too hairy' | grep 'error:'
find fs/smb -name '*.o' | xargs rm
find fs/smb -name '*.ko' | xargs rm
rm build-fs-smb.out
exit 1
The DB is too big and too dependent on your .config but I should
share the smatch_data/ more regularly. I started to push that into
a separate git repo but I didn't finish that work. I should do
that.
Ok, what's the gain of updating it?
Does it help when doing fixes on old kernels?
I'm typically doing a full kernel build a week after each rc.
My idea was to rebuild the whole db after doing that.
Thanks!
metze
