On Thu, Sep 5, 2019 at 12:40 AM Nathan Chancellor <natechancellor@xxxxxxxxx> wrote: > On Wed, Sep 04, 2019 at 11:46:45PM +0200, Arnd Bergmann wrote: > > On Sat, Aug 31, 2019 at 6:26 PM Masahiro Yamada > > <yamada.masahiro@xxxxxxxxxxxxx> wrote: > > > > FWIW, I just found out I missed a bug that clang failed to warn about > > because of the -Wno-format. Apparently gcc warns only about type > > mismatches that result in incompatible calling conventions (e.g. > > int vs int64_t) but not smaller types (int, short) that get converted to an > > int anyway. Passing -Wno-format turns both off. > > > > Arnd > > Hi Arnd, > > This has been fixed in clang 10.0.0 but this areas has not been updated > as nobody has sent a patch yet: > > https://github.com/ClangBuiltLinux/linux/issues/378#issuecomment-524411147 Ok, that's good. I see that on clang-9, the documentation also mentions that -Wformat control -Wformat-extra-args -Wformat-invalid-specifier -Wformat-y2k -Wformat-zero-length -Wnonnull and -Wformat-security. We can probably turn these all on, regardless. The only warning that produces output here is -Wformat-security, and only in a couple of files (number of warnings per file from a few hundred randconfig builds): 384 kernel/trace/ring_buffer_benchmark.c 176 samples/trace_printk/trace-printk.c 174 kernel/debug/kdb/kdb_io.c 102 arch/x86/kernel/e820.c 80 fs/btrfs/check-integrity.c 67 fs/reiserfs/prints.c 63 fs/xfs/xfs_log_recover.c 54 fs/quota/dquot.c 53 lib/test_printf.c 39 sound/core/sound.c 28 arch/x86/kernel/cpu/mce/core.c 21 kernel/trace/preemptirq_delay_test.c 19 sound/core/seq/seq_clientmgr.c 17 sound/pci/hda/hda_bind.c 16 sound/usb/mixer_quirks.c 16 arch/x86/kernel/cpu/mce/amd.c 15 net/smc/smc_ism.c 12 kernel/debug/kdb/kdb_main.c 8 net/netfilter/nf_conntrack_helper.c 4 kernel/power/suspend_test.c 3 sound/pci/rme32.c 3 net/dsa/dsa.c 2 sound/pci/rme96.c 1 sound/soc/sof/intel/hda-codec.c 1 sound/pci/korg1212/korg1212.c Arnd
