powerpc: Rearrange SLB preload code (5eb9bac0) · Commits · 戴 / test

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 <anton@samba.org> Signed-off-by:

Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/mm/slb.c

+8 −13

Original line number	Diff line number	Diff line
		@@ -218,22 +218,17 @@ void switch_slb(struct task_struct tsk, struct mm_struct mm)
		else
		unmapped_base = TASK_UNMAPPED_BASE_USER64;

		if (is_kernel_addr(pc))
		if (is_kernel_addr(pc) \|\| is_kernel_addr(stack) \|\|
		is_kernel_addr(unmapped_base))
		return;
		slb_allocate(pc);

		if (esids_match(pc,stack))
		return;
		slb_allocate(pc);

		if (is_kernel_addr(stack))
		return;
		if (!esids_match(pc, stack))
		slb_allocate(stack);

		if (esids_match(pc,unmapped_base) \|\| esids_match(stack,unmapped_base))
		return;

		if (is_kernel_addr(unmapped_base))
		return;
		if (!esids_match(pc, unmapped_base) &&
		!esids_match(stack, unmapped_base))
		slb_allocate(unmapped_base);
		}

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