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 <andrew.coop...@citrix.com>
Cc: Boris Ostrovsky <boris.ostrov...@oracle.com>
Cc: David Vrabel <dvra...@cantab.net>
Cc: Jan Beulich <jbeul...@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Cc: xen-devel <xen-de...@lists.xen.org>
Signed-off-by: Andy Lutomirski <l...@kernel.org>
---
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
