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Commit 45dbea5f authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
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x86/paravirt: Fix native_patch() 



While chasing a regression I noticed we potentially patch the wrong
code in native_patch().

If we do not select the native code sequence, we must use the default
patcher, not fall-through the switch case.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel test robot <xiaolong.ye@intel.com>
Fixes: 3cded417 ("x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted()")
Link: http://lkml.kernel.org/r/20161208154349.270616999@infradead.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 6f387515

arch/x86/kernel/paravirt_patch_32.c

+4 −0
Original line number Original line Diff line number Diff line
@@ -58,15 +58,19 @@ unsigned native_patch(u8 type, u16 clobbers, void *ibuf, 
				end   = end_pv_lock_ops_queued_spin_unlock;

				end   = end_pv_lock_ops_queued_spin_unlock;

				goto patch_site;

				goto patch_site;

			}

			}

			goto patch_default;



		case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):

		case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):

			if (pv_is_native_vcpu_is_preempted()) {

			if (pv_is_native_vcpu_is_preempted()) {

				start = start_pv_lock_ops_vcpu_is_preempted;

				start = start_pv_lock_ops_vcpu_is_preempted;

				end   = end_pv_lock_ops_vcpu_is_preempted;

				end   = end_pv_lock_ops_vcpu_is_preempted;

				goto patch_site;

				goto patch_site;

			}

			}

			goto patch_default;

#endif

#endif





	default:

	default:

patch_default:

		ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);

		ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);

		break;

		break;

arch/x86/kernel/paravirt_patch_64.c

+4 −0
Original line number Original line Diff line number Diff line
@@ -70,15 +70,19 @@ unsigned native_patch(u8 type, u16 clobbers, void *ibuf, 
				end   = end_pv_lock_ops_queued_spin_unlock;

				end   = end_pv_lock_ops_queued_spin_unlock;

				goto patch_site;

				goto patch_site;

			}

			}

			goto patch_default;



		case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):

		case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):

			if (pv_is_native_vcpu_is_preempted()) {

			if (pv_is_native_vcpu_is_preempted()) {

				start = start_pv_lock_ops_vcpu_is_preempted;

				start = start_pv_lock_ops_vcpu_is_preempted;

				end   = end_pv_lock_ops_vcpu_is_preempted;

				end   = end_pv_lock_ops_vcpu_is_preempted;

				goto patch_site;

				goto patch_site;

			}

			}

			goto patch_default;

#endif

#endif





	default:

	default:

patch_default:

		ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);

		ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);

		break;

		break;