Messages in this thread | | | From | Arnd Bergmann <> | Date | Sat, 26 Sep 2020 17:14:46 +0200 | Subject | Re: [PATCH 4/4] mm: remove compat numa syscalls |
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On Sat, Sep 19, 2020 at 7:41 AM Christoph Hellwig <hch@infradead.org> wrote: > On Fri, Sep 18, 2020 at 03:24:39PM +0200, Arnd Bergmann wrote:
> > +static int get_bitmap(unsigned long *mask, const unsigned long __user *nmask, > > + unsigned long maxnode) > > +{ > > + unsigned long nlongs = BITS_TO_LONGS(maxnode); > > + int ret; > > + > > + if (in_compat_syscall()) > > + ret = compat_get_bitmap(mask, (void __user *)nmask, maxnode); > > I'd either pass void __user all the way, or do an explicit case from > the native to the compat version in the compat handler.
Changed to
if (in_compat_syscall()) ret = compat_get_bitmap(mask, (const compat_ulong_t __user *)nmask, maxnode);
> > + else > > + ret = copy_from_user(mask, nmask, nlongs*sizeof(unsigned long)); > > That whole BITS_TO_LONGS(b) * sizeof(unsigned long) pattern is > duplicated in various places including the checking of compat vs native > and probably want a helper that includes the in_compat_syscall() check.
I don't see what you mean here. I can see how having the helper would simplify copy_nodes_to_user(), but not how it can be shared with the use in get_bitmap()/get_nodes().
Arnd
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