On Fri, Sep 21, 2018 at 03:22:33PM +0100, Kieran Bingham wrote: > kernel/bounds.c is recompiled on every build, and shows the following > warning when compiling with W=1: Don't do that, you will get a lot of warnings that really don't make much sense. Like this one :) > > CC kernel/bounds.s > linux/kernel/bounds.c:16:6: warning: no previous prototype for ‘foo’ [-Wmissing-prototypes] > void foo(void) > ^~~ > > Provide a prototype to satisfy the compiler. > > Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > > --- > I compile all of my incremental builds with W=1, which allows me to know > instantly if I add a new compiler warning in code I generate. > > This warning always comes up and seems trivial to clean up. > --- > kernel/bounds.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/bounds.c b/kernel/bounds.c > index c373e887c066..60136d937800 100644 > --- a/kernel/bounds.c > +++ b/kernel/bounds.c > @@ -13,6 +13,8 @@ > #include <linux/log2.h> > #include <linux/spinlock_types.h> > > +void foo(void); > + > void foo(void) This file is a userspace tool that is used to later generate the include/generated/bounds.h file. If you really want to track this down and fix it properly, put the prototype in the .c file that ends up calling this function. That's a fun task to dig through the build system to find :) good luck! greg k-h