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

This reverts commit 4dbc88bd2b6a74fd33483ee2593dcf2bd858eabe.

Bug: 31432001
Change-Id: I2c3d591a2c631e7ff02c0bcb91624735e8c12f0a
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

diff --git a/arch/arm64/xen/hypercall.S b/arch/arm64/xen/hypercall.S
index 6d6e4af1a4bfb2e6354a242c0638a813d3f173d0..8bbe9401f4f011d3239adcd2d6f5251d5fe37ff0 100644 (file)
--- a/arch/arm64/xen/hypercall.S
+++ b/arch/arm64/xen/hypercall.S
@@ -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);