In aa1acff356bb ("x86/xen: Probe target addresses in
set_aliased_prot() before the hypercall"), I added an explicit probe
to work around a hypercall issue. The code can be simplified by
using probe_kernel_read.
Cc: Andrew Cooper <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: David Vrabel <[email protected]>
Cc: Jan Beulich <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: xen-devel <[email protected]>
Signed-off-by: Andy Lutomirski <[email protected]>
---
arch/x86/xen/enlighten.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 6ab672233ac9..eed696c229ba 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -521,9 +521,7 @@ static void set_aliased_prot(void *v, pgprot_t prot)
preempt_disable();
- pagefault_disable(); /* Avoid warnings due to being atomic. */
- __get_user(dummy, (unsigned char __user __force *)v);
- pagefault_enable();
+ probe_kernel_read(&dummy, (unsigned char *)v, 1);
if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
BUG();
--
2.5.5
