diff options
| author | Andy Lutomirski <[email protected]> | 2016-05-24 15:48:38 -0700 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2016-06-11 11:28:11 +0200 |
| commit | 99158f10e91768d34c5004c40c42f802b719bcae (patch) | |
| tree | be7ebaf9fcbdf9be940531fa481f66a119d4ea18 | |
| parent | 50c0587eedc15235144216f2d2a5bd2a85e03289 (diff) | |
x86/xen: Simplify set_aliased_prot()
A year ago, via the following commit:
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().
No change in functionality.
Signed-off-by: Andy Lutomirski <[email protected]>
Reviewed-by: Andrew Cooper <[email protected]>
Acked-by: David Vrabel <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: David Vrabel <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Jan Beulich <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: xen-devel <[email protected]>
Link: http://lkml.kernel.org/r/0706f1a2538e481194514197298cca6b5e3f2638.1464129798.git.luto@kernel.org
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | arch/x86/xen/enlighten.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 760789ae8562..0f87db2cc6a8 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, v, 1); if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0)) BUG(); |