From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A7A6C433EF for ; Mon, 20 Sep 2021 17:20:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 33A5C63271 for ; Mon, 20 Sep 2021 17:20:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349046AbhITRVZ (ORCPT ); Mon, 20 Sep 2021 13:21:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:49662 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348483AbhITRTZ (ORCPT ); Mon, 20 Sep 2021 13:19:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id DEDAE61A57; Mon, 20 Sep 2021 17:00:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632157209; bh=Ot/FDJFtnw+pBdIG0OnEiwayk1++YKhfnNyyQLhvyLI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YJrxMdiFtaYOJkYP0r6U+T2zQEOgv5H+1ipgMjg3SbqYpK+GdVhjQ7GPqtzFDEzfk Y2u2e6wr0oEyYEfP07iVbUpeMiPl8zjsikx4T82RNVoOa86tPHqD4Mg4agwl0wAVN4 wtuMxm/ZAF4Q44EeyT3+dUf6pPvJugllasxDZOv0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nageswara R Sastry , Kajol Jain , Michael Ellerman Subject: [PATCH 4.14 102/217] powerpc/perf/hv-gpci: Fix counter value parsing Date: Mon, 20 Sep 2021 18:42:03 +0200 Message-Id: <20210920163928.094526537@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210920163924.591371269@linuxfoundation.org> References: <20210920163924.591371269@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kajol Jain commit f9addd85fbfacf0d155e83dbee8696d6df5ed0c7 upstream. H_GetPerformanceCounterInfo (0xF080) hcall returns the counter data in the result buffer. Result buffer has specific format defined in the PAPR specification. One of the fields is counter offset and width of the counter data returned. Counter data are returned in a unsigned char array in big endian byte order. To get the final counter data, the values must be left shifted byte at a time. But commit 220a0c609ad17 ("powerpc/perf: Add support for the hv gpci (get performance counter info) interface") made the shifting bitwise and also assumed little endian order. Because of that, hcall counters values are reported incorrectly. In particular this can lead to counters go backwards which messes up the counter prev vs now calculation and leads to huge counter value reporting: #: perf stat -e hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ -C 0 -I 1000 time counts unit events 1.000078854 18,446,744,073,709,535,232 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ 2.000213293 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ 3.000320107 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ 4.000428392 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ 5.000537864 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ 6.000649087 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ 7.000760312 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ 8.000865218 16,448 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ 9.000978985 18,446,744,073,709,535,232 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ 10.001088891 16,384 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ 11.001201435 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ 12.001307937 18,446,744,073,709,535,232 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ Fix the shifting logic to correct match the format, ie. read bytes in big endian order. Fixes: e4f226b1580b ("powerpc/perf/hv-gpci: Increase request buffer size") Cc: stable@vger.kernel.org # v4.6+ Reported-by: Nageswara R Sastry Signed-off-by: Kajol Jain Tested-by: Nageswara R Sastry Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210813082158.429023-1-kjain@linux.ibm.com Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/perf/hv-gpci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/powerpc/perf/hv-gpci.c +++ b/arch/powerpc/perf/hv-gpci.c @@ -168,7 +168,7 @@ static unsigned long single_gpci_request */ count = 0; for (i = offset; i < offset + length; i++) - count |= arg->bytes[i] << (i - offset); + count |= (u64)(arg->bytes[i]) << ((length - 1 - (i - offset)) * 8); *value = count; out: