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authorMarek Marczykowski-Górecki <marmarek@invisiblethingslab.com>2017-06-26 14:49:46 +0200
committerJuergen Gross <jgross@suse.com>2017-07-03 13:26:17 +0200
commitc54590cac51db8ab5fd30156bdaba34af915e629 (patch)
tree675db462622402556032c4d798641f728882be8a /arch/x86
parentbf1b9ddf181d29ec91f87d9c52bcb551ccf04157 (diff)
x86/xen: allow userspace access during hypercalls
Userspace application can do a hypercall through /dev/xen/privcmd, and some for some hypercalls argument is a pointers to user-provided structure. When SMAP is supported and enabled, hypervisor can't access. So, lets allow it. The same applies to HYPERVISOR_dm_op, where additionally privcmd driver carefully verify buffer addresses. Cc: stable@vger.kernel.org Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/xen/hypercall.h9
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h
index 7a4db5fefd15..11071fcd630e 100644
--- a/arch/x86/include/asm/xen/hypercall.h
+++ b/arch/x86/include/asm/xen/hypercall.h
@@ -43,6 +43,7 @@
#include <asm/page.h>
#include <asm/pgtable.h>
+#include <asm/smap.h>
#include <xen/interface/xen.h>
#include <xen/interface/sched.h>
@@ -216,10 +217,12 @@ privcmd_call(unsigned call,
__HYPERCALL_DECLS;
__HYPERCALL_5ARG(a1, a2, a3, a4, a5);
+ stac();
asm volatile("call *%[call]"
: __HYPERCALL_5PARAM
: [call] "a" (&hypercall_page[call])
: __HYPERCALL_CLOBBER5);
+ clac();
return (long)__res;
}
@@ -478,7 +481,11 @@ static inline int
HYPERVISOR_dm_op(
domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs)
{
- return _hypercall3(int, dm_op, dom, nr_bufs, bufs);
+ int ret;
+ stac();
+ ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs);
+ clac();
+ return ret;
}
static inline void