From 5eb9bac0406f2beb84b21aac6feb89d33d9f3f5c Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Mon, 13 Jul 2009 20:53:52 +0000 Subject: [PATCH] powerpc: Rearrange SLB preload code With the new top down layout it is likely that the pc and stack will be in the same segment, because the pc is most likely in a library allocated via a top down mmap. Right now we bail out early if these segments match. Rearrange the SLB preload code to sanity check all SLB preload addresses are not in the kernel, then check all addresses for conflicts. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/mm/slb.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c index 5b7038f..227056c 100644 --- a/arch/powerpc/mm/slb.c +++ b/arch/powerpc/mm/slb.c @@ -218,23 +218,18 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm) else unmapped_base = TASK_UNMAPPED_BASE_USER64; - if (is_kernel_addr(pc)) - return; - slb_allocate(pc); - - if (esids_match(pc,stack)) + if (is_kernel_addr(pc) || is_kernel_addr(stack) || + is_kernel_addr(unmapped_base)) return; - if (is_kernel_addr(stack)) - return; - slb_allocate(stack); + slb_allocate(pc); - if (esids_match(pc,unmapped_base) || esids_match(stack,unmapped_base)) - return; + if (!esids_match(pc, stack)) + slb_allocate(stack); - if (is_kernel_addr(unmapped_base)) - return; - slb_allocate(unmapped_base); + if (!esids_match(pc, unmapped_base) && + !esids_match(stack, unmapped_base)) + slb_allocate(unmapped_base); } static inline void patch_slb_encoding(unsigned int *insn_addr, -- 2.7.4