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authorSami Tolvanen <samitolvanen@google.com>2016-12-14 12:32:07 -0800
committerSami Tolvanen <samitolvanen@google.com>2017-01-04 09:02:08 -0800
commitc558527eedcd5e166fb91db26ed183e5b88e036f (patch)
tree390c48f85ebb673dcb76d09ba97834f9125f2d93
parent9ce0ba91cecce1377d9fca96eb097c428a44054f (diff)
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>
-rw-r--r--arch/arm64/xen/hypercall.S19
1 files changed, 0 insertions, 19 deletions
diff --git a/arch/arm64/xen/hypercall.S b/arch/arm64/xen/hypercall.S
index 6d6e4af1a4bf..8bbe9401f4f0 100644
--- 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);