On Tue, 2011-07-26 at 23:50 -0700, Mike Frysinger wrote: > On Mon, Jul 18, 2011 at 21:29, Benjamin Herrenschmidt wrote: > > The futex code currently attempts to write to user memory within > > a pagefault disabled section, and if that fails, tries to fix it > > up using get_user_pages(). > > > > This doesn't work on archs where the dirty and young bits are > > maintained by software, since they will gate access permission > > in the TLB, and will not be updated by gup(). > > > > In addition, there's an expectation on some archs that a > > spurious write fault triggers a local TLB flush, and that is > > missing from the picture as well. > > > > I decided that adding those "features" to gup() would be too much > > for this already too complex function, and instead added a new > > simpler fixup_user_fault() which is essentially a wrapper around > > handle_mm_fault() which the futex code can call. > > unfortunately, this breaks all nommu ports. you added > fixup_user_fault() to mm/memory.c only which is not used by nommu
Argh. Andrew, do you want to send a fix ? I won't be able to do that tonight, I have to go. What should nommu do anyways ? it's not like there's much it can do right ? It should never even hit the fault path to start with ... Cheers, Ben. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
