From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936022AbcA0Ukc (ORCPT ); Wed, 27 Jan 2016 15:40:32 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:43750 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161286AbcA0UkU (ORCPT ); Wed, 27 Jan 2016 15:40:20 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Stephane Eranian , "Peter Zijlstra (Intel)" , Arnaldo Carvalho de Melo , Jiri Olsa , Linus Torvalds , Thomas Gleixner , Vince Weaver , kan.liang@intel.com, Ingo Molnar , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 220/268] perf/x86: fix PEBS issues on Intel Atom/Core2 Date: Wed, 27 Jan 2016 12:34:41 -0800 Message-Id: <1453926929-17663-221-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1453926929-17663-1-git-send-email-kamal@canonical.com> References: <1453926929-17663-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.2.8-ckt3 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Stephane Eranian commit 1424a09a9e1839285e948d4ea9fdfca26c9a2086 upstream. This patch fixes broken PEBS support on Intel Atom and Core2 due to wrong pointer arithmetic in intel_pmu_drain_pebs_core(). The get_next_pebs_record_by_bit() was called on PEBS format fmt0 which does not use the pebs_record_nhm layout. Signed-off-by: Stephane Eranian Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vince Weaver Cc: kan.liang@intel.com Fixes: 21509084f999 ("perf/x86/intel: Handle multiple records in the PEBS buffer") Link: http://lkml.kernel.org/r/1449182000-31524-3-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar Signed-off-by: Kamal Mostafa --- arch/x86/kernel/cpu/perf_event_intel_ds.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c index 71fc402..dbe8d89 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -1027,6 +1027,13 @@ get_next_pebs_record_by_bit(void *base, void *top, int bit) void *at; u64 pebs_status; + /* + * fmt0 does not have a status bitfield (does not use + * perf_record_nhm format) + */ + if (x86_pmu.intel_cap.pebs_format < 1) + return base; + if (base == NULL) return NULL; @@ -1112,7 +1119,7 @@ static void intel_pmu_drain_pebs_core(struct pt_regs *iregs) if (!event->attr.precise_ip) return; - n = (top - at) / x86_pmu.pebs_record_size; + n = top - at; if (n <= 0) return; -- 1.9.1