ARM: 7768/1: prevent risks of out-of-bound access in ASID allocator
On a CPU that never ran anything, both the active and reserved ASID fields are set to zero. In this case the ASID_TO_IDX() macro will return -1, which is not a very useful value to index a bitmap. Instead of trying to offset the ASID so that ASID #1 is actually bit 0 in the asid_map bitmap, just always ignore bit 0 and start the search from bit 1. This makes the code a bit more readable, and without risk of OoB access. Cc: <stable@vger.kernel.org> # 3.9 Acked-by: NWill Deacon <will.deacon@arm.com> Acked-by: NCatalin Marinas <catalin.marinas@arm.com> Reported-by: NCatalin Marinas <catalin.marinas@arm.com> Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
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