On Sat, 2018-10-13 at 13:18:31 UTC, Michael Ellerman wrote: > From: Nicholas Piggin <npig...@gmail.com> > > This patch moves SLB miss handlers completely to C, using the standard > exception handler macros to set up the stack and branch to C. > > This can be done because the segment containing the kernel stack is > always bolted, so accessing it with relocation on will not cause an > SLB exception. > > Arbitrary kernel memory must not be accessed when handling kernel > space SLB misses, so care should be taken there. However user SLB > misses can access any kernel memory, which can be used to move some > fields out of the paca (in later patches). > > User SLB misses could quite easily reconcile IRQs and set up a first > class kernel environment and exit via ret_from_except, however that > doesn't seem to be necessary at the moment, so we only do that if a > bad fault is encountered. > > [ Credit to Aneesh for bug fixes, error checks, and improvements to > bad address handling, etc ] > > Signed-off-by: Nicholas Piggin <npig...@gmail.com> > [mpe: Disallow tracing for all of slb.c for now.] > Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
Series applied to powerpc next. https://git.kernel.org/powerpc/c/48e7b76957457f9a6f086ca2bbe49e cheers
