3.2.63-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "David S. Miller" <davem@xxxxxxxxxxxxx> [ Upstream commit 18f38132528c3e603c66ea464727b29e9bbcb91b ] The assumption was that update_mmu_cache() (and the equivalent for PMDs) would only be called when the PTE being installed will be accessible by the user. This is not true for code paths originating from remove_migration_pte(). There are dire consequences for placing a non-valid PTE into the TSB. The TLB miss frramework assumes thatwhen a TSB entry matches we can just load it into the TLB and return from the TLB miss trap. So if a non-valid PTE is in there, we will deadlock taking the TLB miss over and over, never satisfying the miss. Just exit early from update_mmu_cache() and friends in this situation. Based upon a report and patch from Christopher Alexander Tobias Schulze. Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- arch/sparc/mm/init_64.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c index b4989f9..77ad815 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -309,6 +309,10 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t * tsb_index = MM_TSB_BASE; tsb_hash_shift = PAGE_SHIFT; + /* Don't insert a non-valid PTE into the TSB, we'll deadlock. */ + if (!(pte_val(pte) & _PAGE_VALID)) + return; + spin_lock_irqsave(&mm->context.lock, flags); #ifdef CONFIG_HUGETLB_PAGE -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html