powerpc/mm: Fix SMP issue with MMU context handling code
authorKumar Gala <galak@kernel.crashing.org>
Thu, 30 Jul 2009 04:04:25 +0000 (23:04 -0500)
committerKumar Gala <galak@kernel.crashing.org>
Thu, 30 Jul 2009 04:05:43 +0000 (23:05 -0500)
In switch_mmu_context() if we call steal_context_smp() to get a context
to use we shouldn't fall through and than call steal_context_up().  Doing
so can be problematic in that the 'mm' that steal_context_up() ends up
using will not get marked dirty in the stale_map[] for other CPUs that
might have used that mm.  Thus we could end up with stale TLB entries in
the other CPUs that can cause all kinda of havoc.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
arch/powerpc/mm/mmu_context_nohash.c

index 92a197117d5b8012f57f83bb5d8fd56dcc055799..b1a727def15b4a49b01f850ef76d8388d7ce1853 100644 (file)
@@ -217,6 +217,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next)
                        id = steal_context_smp(id);
                        if (id == MMU_NO_CONTEXT)
                                goto again;
+                       goto stolen;
                }
 #endif /* CONFIG_SMP */
                id = steal_context_up(id);