[PATCH v2 2/2] arm64: mm: treat memstart_addr as a signed quantity
From: catalin.marinas@arm.com (Catalin Marinas)
Date: 2016-02-29 18:36:36
From: catalin.marinas@arm.com (Catalin Marinas)
Date: 2016-02-29 18:36:36
On Fri, Feb 26, 2016 at 05:57:14PM +0100, Ard Biesheuvel wrote:
Commit c031a4213c11 ("arm64: kaslr: randomize the linear region")
implements randomization of the linear region, by subtracting a random
multiple of PUD_SIZE from memstart_addr. This causes the virtual mapping
of system RAM to move upwards in the linear region, and at the same time
causes memstart_addr to assume a value which may be negative if the offset
of system RAM in the physical space is smaller than its offset relative to
PAGE_OFFSET in the virtual space.
Since memstart_addr is effectively an offset now, redefine its type as s64
so that expressions involving shifting or division preserve its sign.
Signed-off-by: Ard Biesheuvel <redacted>Applied. Thanks. -- Catalin