On Wed, Jan 23, 2019 at 1:04 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Wed, Jan 23, 2019 at 03:03:47AM -0800, Kees Cook wrote: > > Variables declared in a switch statement before any case statements > > cannot be initialized, so move all instances out of the switches. > > After this, future always-initialized stack variables will work > > and not throw warnings like this: > > > > fs/fcntl.c: In function ‘send_sigio_to_task’: > > fs/fcntl.c:738:13: warning: statement will never be executed [-Wswitch-unreachable] > > siginfo_t si; > > ^~ > > That's a pain, so this means we can't have any new variables in { } > scope except for at the top of a function? AFAICS this only applies to switch statements (because they jump to a case and don't execute stuff at the start of the block), not blocks after if/while/... . > That's going to be a hard thing to keep from happening over time, as > this is valid C :(