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authorAndy Lutomirski <luto@kernel.org>2016-03-16 14:14:21 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-04-12 09:08:38 -0700
commit0f63ab5873ed78838afa4b2f8bfd9d18f806cf40 (patch)
tree9366afab9ccb34b1d9bde5792eca5825b4609c4e /arch/x86/xen
parent1eeb3225856a914d199f92d2d492142783eb5740 (diff)
x86/iopl/64: Properly context-switch IOPL on Xen PV
commit b7a584598aea7ca73140cb87b40319944dd3393f upstream. On Xen PV, regs->flags doesn't reliably reflect IOPL and the exit-to-userspace code doesn't change IOPL. We need to context switch it manually. I'm doing this without going through paravirt because this is specific to Xen PV. After the dust settles, we can merge this with the 32-bit code, tidy up the iopl syscall implementation, and remove the set_iopl pvop entirely. Fixes XSA-171. Reviewewd-by: Jan Beulich <JBeulich@suse.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan Beulich <JBeulich@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/693c3bd7aeb4d3c27c92c622b7d0f554a458173c.1458162709.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/xen')
-rw-r--r--arch/x86/xen/enlighten.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index b7de78bdc09c..beab8c706ac9 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -961,7 +961,7 @@ static void xen_load_sp0(struct tss_struct *tss,
tss->x86_tss.sp0 = thread->sp0;
}
-static void xen_set_iopl_mask(unsigned mask)
+void xen_set_iopl_mask(unsigned mask)
{
struct physdev_set_iopl set_iopl;