4.14-stable review patch. If anyone has any objections, please let me know.
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From: Michael Ellerman mpe@ellerman.id.au
commit 7ece370996b694ae263025e056ad785afc1be5ab upstream.
Currently userspace is able to request mmap() search between 128T-512T by specifying a hint address that is greater than 128T. But that means a hint of 128T exactly will return an address below 128T, which is confusing and wrong.
So fix the logic to check the hint is greater than *or equal* to 128T.
Fixes: f4ea6dcb08ea ("powerpc/mm: Enable mappings above 128TB") Suggested-by: Aneesh Kumar K.V aneesh.kumar@linux.vnet.ibm.com Suggested-by: Nicholas Piggin npiggin@gmail.com [mpe: Split out of Nick's bigger patch] Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/mm/slice.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/powerpc/mm/slice.c +++ b/arch/powerpc/mm/slice.c @@ -419,7 +419,7 @@ unsigned long slice_get_unmapped_area(un /* * Check if we need to expland slice area. */ - if (unlikely(addr > mm->context.addr_limit && + if (unlikely(addr >= mm->context.addr_limit && mm->context.addr_limit != TASK_SIZE)) { mm->context.addr_limit = TASK_SIZE; on_each_cpu(slice_flush_segments, mm, 1); @@ -427,7 +427,7 @@ unsigned long slice_get_unmapped_area(un /* * This mmap request can allocate upt to 512TB */ - if (addr > DEFAULT_MAP_WINDOW) + if (addr >= DEFAULT_MAP_WINDOW) high_limit = mm->context.addr_limit; else high_limit = DEFAULT_MAP_WINDOW;