On Fri, Jul 21, 2023 at 05:41:20PM +0200, Arnd Bergmann wrote: > On Fri, Jul 21, 2023, at 12:22, Peter Zijlstra wrote: > > --- a/arch/arm/tools/syscall.tbl > > +++ b/arch/arm/tools/syscall.tbl > > @@ -465,3 +465,4 @@ > > 449 common futex_waitv sys_futex_waitv > > 450 common set_mempolicy_home_node sys_set_mempolicy_home_node > > 451 common cachestat sys_cachestat > > +452 common futex_wake sys_futex_wake > > This clashes with __NR_fchmodat2 in linux-next, which also wants number 452. Yeah, I fully expected some collisions :/ Unavoidable. > > --- a/arch/arm64/include/asm/unistd32.h > > +++ b/arch/arm64/include/asm/unistd32.h > > @@ -909,6 +909,8 @@ __SYSCALL(__NR_futex_waitv, sys_futex_wa > > __SYSCALL(__NR_set_mempolicy_home_node, sys_set_mempolicy_home_node) > > #define __NR_cachestat 451 > > __SYSCALL(__NR_cachestat, sys_cachestat) > > +#define __NR_futex_wake 452 > > +__SYSCALL(__NR_futex_wake, sys_futex_wake) > > > > /* > > * Please add new compat syscalls above this comment and update > > Unfortunately, changing this file still requires updating __NR_compat_syscalls > in arch/arm64/include/asm/unistd.h as well. Bah I missed that. I'll go fix it up. Thanks! > > --- a/kernel/sys_ni.c > > +++ b/kernel/sys_ni.c > > @@ -87,6 +87,7 @@ COND_SYSCALL_COMPAT(set_robust_list); > > COND_SYSCALL(get_robust_list); > > COND_SYSCALL_COMPAT(get_robust_list); > > COND_SYSCALL(futex_waitv); > > +COND_SYSCALL(futex_wake); > > COND_SYSCALL(kexec_load); > > COND_SYSCALL_COMPAT(kexec_load); > > COND_SYSCALL(init_module); > > This is fine for the moment, but I wonder if we should start making > futex mandatory at some point. Right now, sparc32 with CONFIG_SMP > cannot support futex because of the lack of atomics in early > sparc processors, but sparc32 glibc actually requires futexes > and consequently only works on uniprocessor machines, on sparc64 > compat mode, or on Leon3 with out of tree patches. PARISC is another 'fun' case.