On Sat, May 6, 2023 at 10:35 AM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Fri, May 5, 2023, at 22:34, Andrew Morton wrote: > > On Thu, 4 May 2023 19:26:11 +0200 Geert Uytterhoeven > > <geert@xxxxxxxxxxxxxx> wrote: > > > >> > arch/x86/entry/syscalls/syscall_32.tbl | 1 + > >> > arch/x86/entry/syscalls/syscall_64.tbl | 1 + > >> > >> This should be wired up on each and every architecture. > >> Currently we're getting > >> > >> <stdin>:1567:2: warning: #warning syscall cachestat not implemented [-Wcpp] > >> > >> in linux-next for all the missing architectures. > > > > Is that wise? We risk adding a syscall to an architecture without the > > arch maintainers and testers even knowing about it. > > > > The compile-time nag is there to inform the arch maintainers that a new > > syscall is available and that they should wire it up, run the selftest > > and then ship the code if they're happy with the result. > > The usual approach is for the author of a new syscall to > include a patch with all the architecture specific changes > and Cc the architecture maintainers for that. > > Note that half the architectures get the entry from > include/uapi/asm-generic/unistd.h, so adding it there > does not necessarily trigger adding each maintainer > from scripts/get_maintainer.pl. > > The only real risk in adding a new syscall is passing __u64 > register arguments that behave differently across > architectures, or using pointers to data structures that > require a compat handler on some architectures. I watch out > for those as they get sent to me or the linux-arch list, > and this one is fine. > > Arnd I took a stab at wiring the new syscall in this follow-up patch: https://lore.kernel.org/lkml/20230510195806.2902878-1-nphamcs@xxxxxxxxx/ Let me know if I missed something! Review and/or suggestion is very much appreciated.
