On Wed, 2009-11-18 at 08:04 +0100, Heiko Carstens wrote:
> On Tue, Nov 17, 2009 at 10:23:56AM -0500, Eric Paris wrote:
> > On Tue, 2009-11-17 at 14:55 +0100, Heiko Carstens wrote:
> >
> > > Yes, also some places should have used lgfr instead of llgfr for proper sign
> > > extension. But please, just drop the s390 bits from your patch.
> > > Its easier and less painful for us to do it ourselves instead of reviewing
> > > and fixing these things. (No offence intended!).
> >
> > dropped and won't show up in -next tomorrow.
> >
> > This what I thought it should be and would love to read if you say it's
> > right....
> >
>
> [...]
>
> > +sys32_fanotify_mark_wrapper:
> > + lgfr %r2,%r2 # int
> > + llgfr %r3,%r3 # unsigned int
> > + lgfr %r4,%r4 # int
> > + llgtr %r5,%r5 # char *
> > + sllg %r6,%r6,32 # get high word of 64bit mask
> > + l %r6,164(%r15) # get low word of 64bit mask
> > + jg sys_fanotify_mark
>
> Oh wait, I have to correct myself:
>
> With
>
> long sys_fanotify_mark(int fanotify_fd, unsigned int flags,
> int fd, const char __user *pathname,
> u64 mask);
>
> we have a 64 bit type as 5th argument. That doesn't work for syscalls
> on 32 bit s390.
> I just simplify the reason for this: on 32 bit long longs will be passed via
> two consecutive registers _unless_ the first register would be r6 (which is
> the case here). In that case the whole 64 bits would be passed on the stack.
> Our glibc syscall code will always put the contents of the first parameter
> stack slot into register r7, so we have six registers for parameter passing
> (r2-r7). So with the 64 bit value put into two stack slots we would miss
> the second part of the 5th argument.
asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len);
sys_fallocate_wrapper:
lgfr %r2,%r2 # int
lgfr %r3,%r3 # int
sllg %r4,%r4,32 # get high word of 64bit loff_t
lr %r4,%r5 # get low word of 64bit loff_t
sllg %r5,%r6,32 # get high word of 64bit loff_t
l %r5,164(%r15) # get low word of 64bit loff_t
jg sys_fallocate
Does this work? It's basically the same thing, right? I'm willing to
hear "that's fine you are clueless" Just saw it and hoping that we
have everything right....
-Eric
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