Re: [PATCH v9 8/9] arch, mm: wire up memfd_secret system call were relevant

[Mike Rapoport]

On Tue, Nov 17, 2020 at 05:15:30PM +0000, Catalin Marinas wrote:
> On Tue, Nov 17, 2020 at 06:29:31PM +0200, Mike Rapoport wrote:
> > From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> > 
> > Wire up memfd_secret system call on architectures that define
> > ARCH_HAS_SET_DIRECT_MAP, namely arm64, risc-v and x86.
> > 
> > Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> > Acked-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
> > Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
> > ---
> >  arch/arm64/include/asm/unistd.h        | 2 +-
> >  arch/arm64/include/asm/unistd32.h      | 2 ++
> >  arch/arm64/include/uapi/asm/unistd.h   | 1 +
> >  arch/riscv/include/asm/unistd.h        | 1 +
> >  arch/x86/entry/syscalls/syscall_32.tbl | 1 +
> >  arch/x86/entry/syscalls/syscall_64.tbl | 1 +
> >  include/linux/syscalls.h               | 1 +
> >  include/uapi/asm-generic/unistd.h      | 6 +++++-
> >  scripts/checksyscalls.sh               | 4 ++++
> >  9 files changed, 17 insertions(+), 2 deletions(-)
> > 
> > diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
> > index 86a9d7b3eabe..949788f5ba40 100644
> > --- a/arch/arm64/include/asm/unistd.h
> > +++ b/arch/arm64/include/asm/unistd.h
> > @@ -38,7 +38,7 @@
> >  #define __ARM_NR_compat_set_tls		(__ARM_NR_COMPAT_BASE + 5)
> >  #define __ARM_NR_COMPAT_END		(__ARM_NR_COMPAT_BASE + 0x800)
> >  
> > -#define __NR_compat_syscalls		442
> > +#define __NR_compat_syscalls		443
> >  #endif
> >  
> >  #define __ARCH_WANT_SYS_CLONE
> > diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
> > index 6c1dcca067e0..5279481ec95b 100644
> > --- a/arch/arm64/include/asm/unistd32.h
> > +++ b/arch/arm64/include/asm/unistd32.h
> > @@ -891,6 +891,8 @@ __SYSCALL(__NR_faccessat2, sys_faccessat2)
> >  __SYSCALL(__NR_process_madvise, sys_process_madvise)
> >  #define __NR_watch_mount 441
> >  __SYSCALL(__NR_watch_mount, sys_watch_mount)
> > +/* 442 is memfd_secret, it is not implemented for 32-bit */
> > +__SYSCALL(442, sys_ni_syscall)
> 
> It now behaves correctly for compat but I don't think we need to
> increment __NR_compat_syscalls. The compat syscall handler already calls
> sys_ni_syscall() if out of range.

Ok, let's drop this change as well :)

> So the only arm64 change needed is defining __ARCH_WANT_MEMFD_SECRET
> (well, we don't have a use for it yet ;)).
> 
> -- 
> Catalin

-- 
Sincerely yours,
Mike.