Revert "FROMLIST: arm64: xen: Enable user access before a privcmd hvc call"

This reverts commit 4dbc88bd2b.

Bug: 31432001
Change-Id: I2c3d591a2c631e7ff02c0bcb91624735e8c12f0a
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
This commit is contained in:
Sami Tolvanen 2016-12-14 12:32:07 -08:00 committed by Amit Pundir
parent 2e95b11a7b
commit 91b3735c3d

View file

@ -49,7 +49,6 @@
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/uaccess.h>
#include <xen/interface/xen.h>
@ -90,24 +89,6 @@ ENTRY(privcmd_call)
mov x2, x3
mov x3, x4
mov x4, x5
#ifdef CONFIG_ARM64_SW_TTBR0_PAN
/*
* 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 emulation
* is enabled (it implies that hardware UAO and PAN disabled).
*/
uaccess_enable_not_uao x6, x7
#endif
hvc XEN_IMM
#ifdef CONFIG_ARM64_SW_TTBR0_PAN
/*
* Disable userspace access from kernel once the hyp call completed.
*/
uaccess_disable_not_uao x6
#endif
ret
ENDPROC(privcmd_call);