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Andy Lutomirski authored
commit b7a58459 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.orgSigned-off-by:
Ingo Molnar <mingo@kernel.org> [ kamal: backport to 3.19-stable: no X86_FEATURE_XENPV so just call xen_pv_domain() directly ] Acked-by:
Andy Lutomirski <luto@kernel.org> Signed-off-by:
Kamal Mostafa <kamal@canonical.com> Signed-off-by:
Luis Henriques <luis.henriques@canonical.com>
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