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| author | Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> | 2017-06-26 14:49:46 +0200 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2017-07-03 13:26:17 +0200 |
| commit | c54590cac51db8ab5fd30156bdaba34af915e629 (patch) | |
| tree | 675db462622402556032c4d798641f728882be8a /arch/x86/include/asm/xen/hypercall.h | |
| parent | bf1b9ddf181d29ec91f87d9c52bcb551ccf04157 (diff) | |
| download | lwn-c54590cac51db8ab5fd30156bdaba34af915e629.tar.gz lwn-c54590cac51db8ab5fd30156bdaba34af915e629.zip | |
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/include/asm/xen/hypercall.h')
| -rw-r--r-- | arch/x86/include/asm/xen/hypercall.h | 9 |
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 |