commit 55de49f9aa upstream.
Our compat swp emulation holds the compat user address in an unsigned
int, which it passes to __user_swpX_asm(). When a 32-bit value is passed
in a register, the upper 32 bits of the register are unknown, and we
must extend the value to 64 bits before we can use it as a base address.
This patch casts the address to unsigned long to ensure it has been
suitably extended, avoiding the potential issue, and silencing a related
warning from clang.
Fixes: bd35a4adc4 ("arm64: Port SWP/SWPB emulation support from arm")
Cc: <stable@vger.kernel.org> # 3.19.x-
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mark Rutland
01ce16f40c