Re: [PATCH] x86/xen: allow userspace access during hypercalls

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 06/23/2017 02:47 PM, Marek Marczykowski-Górecki wrote:
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.

What about HYPERVISOR_dm_op?


Juergen


Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
---
  arch/x86/include/asm/xen/hypercall.h | 3 +++
  1 file changed, 3 insertions(+)

diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h
index f6d20f6..a1d2c5d 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>
@@ -214,10 +215,12 @@ 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;
  }





[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]