From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: [PATCH 1/2] x86,paravirt: Fix native_patch() Date: Thu, 08 Dec 2016 16:42:14 +0100 Message-ID: <20161208154349.270616999@infradead.org> References: <20161208154213.952687487@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline; filename=peter_zijlstra-fd6f48529f-_aim7_jobs-per-min_-26_1__regression.patch List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: Jeremy Fitzhardinge , "Peter Zijlstra (Intel)" , Pan Xinhui , Alok Kataria , kernel test robot , virtualization@lists.linux-foundation.org, Chris Wright , Borislav Petkov , Peter Anvin , Paolo Bonzini , Thomas Gleixner , Ingo Molnar List-Id: virtualization@lists.linuxfoundation.org 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. Fixes: 3cded4179481 ("x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted()") Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/kernel/paravirt_patch_32.c | 4 ++++ arch/x86/kernel/paravirt_patch_64.c | 4 ++++ 2 files changed, 8 insertions(+) --- a/arch/x86/kernel/paravirt_patch_32.c +++ b/arch/x86/kernel/paravirt_patch_32.c @@ -56,15 +56,19 @@ unsigned native_patch(u8 type, u16 clobb end = end_pv_lock_ops_queued_spin_unlock; goto patch_site; } + goto patch_default; + case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted): if (pv_is_native_vcpu_is_preempted()) { start = start_pv_lock_ops_vcpu_is_preempted; end = end_pv_lock_ops_vcpu_is_preempted; goto patch_site; } + goto patch_default; #endif default: +patch_default: ret = paravirt_patch_default(type, clobbers, ibuf, addr, len); break; --- a/arch/x86/kernel/paravirt_patch_64.c +++ b/arch/x86/kernel/paravirt_patch_64.c @@ -68,15 +68,19 @@ unsigned native_patch(u8 type, u16 clobb end = end_pv_lock_ops_queued_spin_unlock; goto patch_site; } + goto patch_default; + case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted): if (pv_is_native_vcpu_is_preempted()) { start = start_pv_lock_ops_vcpu_is_preempted; end = end_pv_lock_ops_vcpu_is_preempted; goto patch_site; } + goto patch_default; #endif default: +patch_default: ret = paravirt_patch_default(type, clobbers, ibuf, addr, len); break;