From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kan Liang , "Peter Zijlstra (Intel)" , Thomas Gleixner , Linus Torvalds , acme@kernel.org, eranian@google.com, Ingo Molnar , Sasha Levin Subject: [PATCH 3.18 14/85] perf/x86/intel/uncore: Correct fixed counter index check in generic code Date: Tue, 7 Aug 2018 20:51:16 +0200 Message-Id: <20180807172357.883218197@linuxfoundation.org> In-Reply-To: <20180807172357.357252052@linuxfoundation.org> References: <20180807172357.357252052@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kan Liang [ Upstream commit 4749f8196452eeb73cf2086a6a9705bae479d33d ] There is no index which is bigger than UNCORE_PMC_IDX_FIXED. The only exception is client IMC uncore, which has been specially handled. For generic code, it is not correct to use >= to check fixed counter. The code quality issue will bring problem when a new counter index is introduced. Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Thomas Gleixner Cc: Linus Torvalds Cc: Peter Zijlstra Cc: acme@kernel.org Cc: eranian@google.com Link: http://lkml.kernel.org/r/1525371913-10597-3-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/perf_event_intel_uncore.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c @@ -175,7 +175,7 @@ void uncore_perf_event_update(struct int u64 prev_count, new_count, delta; int shift; - if (event->hw.idx >= UNCORE_PMC_IDX_FIXED) + if (event->hw.idx == UNCORE_PMC_IDX_FIXED) shift = 64 - uncore_fixed_ctr_bits(box); else shift = 64 - uncore_perf_ctr_bits(box);