UPSTREAM: arm64: xen: Enable user access before a privcmd hvc call
authorCatalin Marinas <catalin.marinas@arm.com>
Tue, 5 Jul 2016 11:25:15 +0000 (12:25 +0100)
committerAmit Pundir <amit.pundir@linaro.org>
Mon, 16 Jan 2017 09:30:56 +0000 (15:00 +0530)
commit62a7c6fac9744a9a1a002a1fb5e3b39c8dca5866
treeb0484057a2d64f1c3ad1ffa265ffa0d723a08cb5
parent23df43f5fcf51d3df59d8c2991810f0d5b329c0a
UPSTREAM: arm64: xen: Enable user access before a privcmd hvc call

Privcmd calls are issued by the userspace. The kernel needs to enable
access to TTBR0_EL1 as the hypervisor would issue stage 1 translations
to user memory via AT instructions. Since AT instructions are not
affected by the PAN bit (ARMv8.1), we only need the explicit
uaccess_enable/disable if the TTBR0 PAN option is enabled.

Reviewed-by: Julien Grall <julien.grall@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Bug: 31432001
Change-Id: I64d827923d869c1868702c8a18efa99ea91d3151
(cherry picked from commit 9cf09d68b89ae5fe0261dcc69464bcc676900af6)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
arch/arm64/xen/hypercall.S