Will Deacon c2f0ad4fc0 arm64: uaccess: Prevent speculative use of the current addr_limit
A mispredicted conditional call to set_fs could result in the wrong
addr_limit being forwarded under speculation to a subsequent access_ok
check, potentially forming part of a spectre-v1 attack using uaccess
routines.

This patch prevents this forwarding from taking place, but putting heavy
barriers in set_fs after writing the addr_limit.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-06 22:53:37 +00:00
..
2017-12-09 20:23:29 -08:00
2018-02-06 22:53:32 +00:00