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 <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Anton Blanchard 2009-07-13 20:53:52 +00:00 committed by Benjamin Herrenschmidt
parent 30d0b36828
commit 5eb9bac040
1 changed files with 8 additions and 13 deletions

View File

@ -218,22 +218,17 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
else else
unmapped_base = TASK_UNMAPPED_BASE_USER64; 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; return;
slb_allocate(pc); slb_allocate(pc);
if (esids_match(pc,stack)) if (!esids_match(pc, stack))
return;
if (is_kernel_addr(stack))
return;
slb_allocate(stack); slb_allocate(stack);
if (esids_match(pc,unmapped_base) || esids_match(stack,unmapped_base)) if (!esids_match(pc, unmapped_base) &&
return; !esids_match(stack, unmapped_base))
if (is_kernel_addr(unmapped_base))
return;
slb_allocate(unmapped_base); slb_allocate(unmapped_base);
} }