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Re: [RFC v2 09/20] sysdeps/getrlimit: Use prlimit64 if avaliable
On Tue, Jun 25, 2019 at 4:11 AM Florian Weimer <fweimer@redhat.com> wrote:
>
> * Alistair Francis:
>
> > If the prlimit64 syscall is avaliable let's use that instead of
> > ugetrlimit as it isn't always avaliable (they aren't avaliable
> > on RV32).
>
> > diff --git a/sysdeps/unix/sysv/linux/getrlimit.c b/sysdeps/unix/sysv/linux/getrlimit.c
> > index 10c0176619..741b065b25 100644
> > --- a/sysdeps/unix/sysv/linux/getrlimit.c
> > +++ b/sysdeps/unix/sysv/linux/getrlimit.c
> > @@ -35,7 +35,16 @@
> > int
> > __new_getrlimit (enum __rlimit_resource resource, struct rlimit *rlim)
> > {
> > +#ifdef __ASSUME_RLIM64_SYSCALLS
> > + return INLINE_SYSCALL_CALL (prlimit64, 0, resource, rlim, NULL);
> > +#else
> > +# ifdef __NR_prlimit64
> > + long int ret = INLINE_SYSCALL_CALL (prlimit64, 0, resource, rlim, NULL);
> > + if (ret == 0 || errno != ENOSYS)
> > + return ret;
> > +# endif
> > return INLINE_SYSCALL_CALL (ugetrlimit, resource, rlim);
> > +#endif
>
> I think that's not correct because with this change, defining
> __ASSUME_RLIM64_SYSCALLS changes the struct expected by getrlimit.
I'm not clear what you mean here, why is the struct expected by
getrlimit different?
> I believe the expectation is that such definitions only alter the set of
> system calls glibc assumes to be present. They should not affect the
> external glibc ABI exposed on its function call interface.
I agree, I don't see how this changes the function call interface though.
Alistair
>
> Thanks,
> Florian