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author | Will Deacon <will.deacon@arm.com> | 2018-02-05 16:34:22 +0100 |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2018-02-06 23:53:39 +0100 |
commit | 84624087dd7e3b482b7b11c170ebc1f329b3a218 (patch) | |
tree | 0f50e8eab78b53f0953ba57488777d66222214f5 /drivers/pwm/pwm-rockchip.c | |
parent | arm64: uaccess: Prevent speculative use of the current addr_limit (diff) | |
download | linux-84624087dd7e3b482b7b11c170ebc1f329b3a218.tar.xz linux-84624087dd7e3b482b7b11c170ebc1f329b3a218.zip |
arm64: uaccess: Don't bother eliding access_ok checks in __{get, put}_user
access_ok isn't an expensive operation once the addr_limit for the current
thread has been loaded into the cache. Given that the initial access_ok
check preceding a sequence of __{get,put}_user operations will take
the brunt of the miss, we can make the __* variants identical to the
full-fat versions, which brings with it the benefits of address masking.
The likely cost in these sequences will be from toggling PAN/UAO, which
we can address later by implementing the *_unsafe versions.
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'drivers/pwm/pwm-rockchip.c')
0 files changed, 0 insertions, 0 deletions