James Morse 3b82a6ea23 Revert "arm64: uaccess: implement unsafe accessors" ... This reverts commit a1f33941f7. The unsafe accessors allow the PAN enable/disable calls to be made once for a group of accesses. Adding these means we can now have sequences that look like this: | user_access_begin(); | unsafe_put_user(static-value, x, err); | unsafe_put_user(helper-that-sleeps(), x, err); | user_access_end(); Calling schedule() without taking an exception doesn't switch the PSTATE or TTBRs. We can switch out of a uaccess-enabled region, and run other code with uaccess enabled for a different thread. We can also switch from uaccess-disabled code back into this region, meaning the unsafe_put_user()s will fault. For software-PAN, threads that do this will get stuck as handle_mm_fault() will determine the page has already been mapped in, but we fault again as the page tables aren't loaded. To solve this we need code in __switch_to() that save/restores the PAN state. Acked-by: Julien Thierry <julien.thierry@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>		2018-10-10 17:52:08 +01:00
..
boot	ARM: SoC: late updates	2018-08-25 14:12:36 -07:00
configs	arm64: defconfig: Enable TI's AM6 SoC platform	2018-08-29 11:51:26 -07:00
crypto	crypto: arm64/aes-gcm-ce - fix scatterwalk API violation	2018-08-25 19:50:43 +08:00
include	Revert "arm64: uaccess: implement unsafe accessors"	2018-10-10 17:52:08 +01:00
kernel	arm64: Trap WFI executed in userspace	2018-10-01 16:52:24 +01:00
kvm	arm64: KVM: Enable Common Not Private translations	2018-09-18 12:03:34 +01:00
lib	arm64: lse: remove -fcall-used-x0 flag	2018-09-24 10:56:24 +01:00
mm	arm64: mm: Drop the unused cpu parameter	2018-10-09 17:17:23 +01:00
net	bpf, arm64: save 4 bytes in prologue when ebpf insns came from cbpf	2018-05-14 19:11:45 -07:00
xen	arm64: mm: Add additional parameter to uaccess_ttbr0_disable	2018-01-17 13:57:49 +01:00
Kconfig	arm64: arch_timer: avoid unused function warning	2018-10-03 11:41:34 +01:00
Kconfig.debug	Kconfig: consolidate the "Kernel hacking" menu	2018-08-02 08:06:48 +09:00
Kconfig.platforms	ARM: SoC: late updates	2018-08-25 14:12:36 -07:00
Makefile	kbuild: rename LDFLAGS to KBUILD_LDFLAGS	2018-08-24 08:22:08 +09:00