Messages in this thread | | | From | Jann Horn <> | Date | Mon, 15 Jun 2020 09:57:40 +0200 | Subject | Re: general protection fault in syscall_return_slowpath |
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On Sun, Jun 14, 2020 at 10:03 AM Dmitry Vyukov <dvyukov@google.com> wrote: > On Tue, Mar 10, 2020 at 9:10 AM Dmitry Vyukov <dvyukov@google.com> wrote: > > On Tue, Mar 10, 2020 at 7:15 AM Nathan Chancellor > > <natechancellor@gmail.com> wrote: > > > > > > On Mon, Mar 09, 2020 at 09:20:58AM +0100, Dmitry Vyukov wrote: > > > > On Sun, Mar 8, 2020 at 7:35 PM 'Jann Horn' via syzkaller-bugs > > > > <syzkaller-bugs@googlegroups.com> wrote: > > > > > Ugh, why does it build with -Werror... > > > > > > There are certain warnings that are specifically treated like errors: > > > > > > In the main Makefile: > > > > > > KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types) > > > > > > > Now I am realizing I don't know what's the proper way to turn off > > > > warnings entirely... > > > > > > > > We turn off this CONFIG_ERROR_ON_WARNING historically: > > > > https://github.com/google/syzkaller/blob/2e9971bbbfb4df6ba0118353163a7703f3dbd6ec/dashboard/config/bits-syzbot.config#L17 > > > > and I thought that's enough. But now I realize it's not even a thing. > > > > I see it referenced in some ChromeOS threads and there are some > > > > discussions re upstreaming, but apparently it never existed upstream. > > > > > > > > make has W=n, but it seems that it can only be used to produce more > > > > warnings. We don't pass W=3 specifically and there is no W=0. > > > > > > > > Should we always build with CFLAGS=-w? Is it guaranteed to work? Or is > > > > there a better way? > > > > > > Would passing -Wno-werror via KCFLAGS work? Otherwise, passing > > > -Wno-error=<specific warning> should work. > > > > > > Cheers, > > > Nathan > > > > Filed https://github.com/google/syzkaller/issues/1635 so that this is not lost. > > Jann, > > Getting back to this. > Are you sure building without warning will be better? > > Currently make enables these warnings as errors only: > > -Werror=strict-prototypes > -Werror=implicit-function-declaration > -Werror=implicit-int > -Werror=date-time > -Werror=incompatible-pointer-types > -Werror=designated-init > > So most warnings won't cause build failure. > And, say, converting T* to Y* implicitly may be an actual bug in the patch.
Ah, I guess you have a point there.
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