From patchwork Tue Mar 26 15:18:53 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 231280 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 4EF802C009F for ; Wed, 27 Mar 2013 02:22:14 +1100 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UKVhP-0007c9-1h; Tue, 26 Mar 2013 15:22:07 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UKVhL-0007Z4-Or for kernel-team@lists.ubuntu.com; Tue, 26 Mar 2013 15:22:03 +0000 Received: from bl20-143-66.dsl.telepac.pt ([2.81.143.66] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UKVhL-0004cl-GF; Tue, 26 Mar 2013 15:22:03 +0000 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 034/150] perf, x86: fix kernel crash with PEBS/BTS after suspend/resume Date: Tue, 26 Mar 2013 15:18:53 +0000 Message-Id: <1364311249-14454-35-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1364311249-14454-1-git-send-email-luis.henriques@canonical.com> References: <1364311249-14454-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Cc: Linus Torvalds , Stephane Eranian X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.5.7.9 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Stephane Eranian commit 1d9d8639c063caf6efc2447f5f26aa637f844ff6 upstream. This patch fixes a kernel crash when using precise sampling (PEBS) after a suspend/resume. Turns out the CPU notifier code is not invoked on CPU0 (BP). Therefore, the DS_AREA (used by PEBS) is not restored properly by the kernel and keeps it power-on/resume value of 0 causing any PEBS measurement to crash when running on CPU0. The workaround is to add a hook in the actual resume code to restore the DS Area MSR value. It is invoked for all CPUS. So for all but CPU0, the DS_AREA will be restored twice but this is harmless. Reported-by: Linus Torvalds Signed-off-by: Stephane Eranian Signed-off-by: Linus Torvalds Signed-off-by: Luis Henriques --- arch/x86/kernel/cpu/perf_event_intel_ds.c | 8 ++++++++ arch/x86/power/cpu.c | 2 ++ include/linux/perf_event.h | 2 ++ 3 files changed, 12 insertions(+) diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c index 35e2192..9a9be1e 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -714,3 +714,11 @@ void intel_ds_init(void) } } } + +void perf_restore_debug_store(void) +{ + if (!x86_pmu.bts && !x86_pmu.pebs) + return; + + init_debug_store_on_cpu(smp_processor_id()); +} diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index 218cdb1..fcbaac60 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -227,6 +228,7 @@ static void __restore_processor_state(struct saved_context *ctxt) do_fpu_end(); x86_platform.restore_sched_clock_state(); mtrr_bp_restore(); + perf_restore_debug_store(); } /* Needed by apm.c */ diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index c3c98a6..1d56bf6 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1295,6 +1295,7 @@ extern void perf_swevent_put_recursion_context(int rctx); extern void perf_event_enable(struct perf_event *event); extern void perf_event_disable(struct perf_event *event); extern void perf_event_task_tick(void); +extern void perf_restore_debug_store(void); #else static inline void perf_event_task_sched_in(struct task_struct *prev, @@ -1333,6 +1334,7 @@ static inline void perf_swevent_put_recursion_context(int rctx) { } static inline void perf_event_enable(struct perf_event *event) { } static inline void perf_event_disable(struct perf_event *event) { } static inline void perf_event_task_tick(void) { } +static inline void perf_restore_debug_store(void) { } #endif #define perf_output_put(handle, x) perf_output_copy((handle), &(x), sizeof(x))