On Wed, 14 Apr 2021 11:10:42 +0200
Christophe Leroy <christophe.leroy@xxxxxxxxxx> wrote:
>
> Le 14/04/2021 à 10:58, Jisheng Zhang a écrit :
> > Many architectures implement the trap_init() as NOP, since there is
> > no such default for trap_init(), this empty stub is duplicated among
> > these architectures. Provide a generic but weak NOP implementation
> > to drop the empty stubs of trap_init() in these architectures.
>
> You define the weak function in the __init section.
>
> Most but not all architectures had it in __init section.
>
> And the remaining ones may not be defined in __init section. For instance look at the one in alpha
> architecture.
>
> Have you checked that it is not a problem ? It would be good to say something about it in the commit
> description.
For those non-nop platforms, I can only test x86/arm64/, but both has
__init mark. I'm not sure whether this is a problem for alpha etc. Maybe
I can check which section the trap_init() sits. Or to avoid any possible
regression, I can add __init mark to those remaining ones without it in
preparation patches.
>
>
> >
> > Signed-off-by: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
> > ---
> > arch/arc/kernel/traps.c | 5 -----
> > arch/arm/kernel/traps.c | 5 -----
> > arch/h8300/kernel/traps.c | 13 -------------
> > arch/hexagon/kernel/traps.c | 4 ----
> > arch/nds32/kernel/traps.c | 5 -----
> > arch/nios2/kernel/traps.c | 5 -----
> > arch/openrisc/kernel/traps.c | 5 -----
> > arch/parisc/kernel/traps.c | 4 ----
> > arch/powerpc/kernel/traps.c | 5 -----
> > arch/riscv/kernel/traps.c | 5 -----
> > arch/um/kernel/trap.c | 4 ----
> > init/main.c | 2 ++
> > 12 files changed, 2 insertions(+), 60 deletions(-)
> >
> > diff --git a/init/main.c b/init/main.c
> > index 53b278845b88..4bdbe2928530 100644
> > --- a/init/main.c
> > +++ b/init/main.c
> > @@ -790,6 +790,8 @@ static inline void initcall_debug_enable(void)
> > }
> > #endif
> >
> > +void __init __weak trap_init(void) { }
> > +
>
> I think in a C file we don't try to save space as much as in a header file.
>
This is to follow most weak NOP implementations in init/main.c to make
the style unified in the same file. I'm not sure which is better.
> I would prefer something like:
>
>
> void __init __weak trap_init(void)
> {
> }
>
>
> > /* Report memory auto-initialization states for this boot. */
> > static void __init report_meminit(void)
> > {
> >
