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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 C66E7C4363A for ; Thu, 8 Oct 2020 13:46:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B57D20782 for ; Thu, 8 Oct 2020 13:46:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730406AbgJHNqZ (ORCPT ); Thu, 8 Oct 2020 09:46:25 -0400 Received: from foss.arm.com ([217.140.110.172]:58508 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730396AbgJHNqZ (ORCPT ); Thu, 8 Oct 2020 09:46:25 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8BA701063; Thu, 8 Oct 2020 06:46:24 -0700 (PDT) Received: from [192.168.2.22] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C61923F70D; Thu, 8 Oct 2020 06:46:22 -0700 (PDT) From: =?UTF-8?Q?Andr=c3=a9_Przywara?= Subject: Re: [PATCH v2 04/14] perf arm-spe: Fix packet length handling To: Leo Yan , Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Wei Li , James Clark , Dave Martin , linux-kernel@vger.kernel.org, Al Grant References: <20200929133917.9224-1-leo.yan@linaro.org> <20200929133917.9224-5-leo.yan@linaro.org> Organization: ARM Ltd. Message-ID: <230f6fbf-02b4-1ce2-bf80-3cbaa16fb587@arm.com> Date: Thu, 8 Oct 2020 14:45:32 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200929133917.9224-5-leo.yan@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 29/09/2020 14:39, Leo Yan wrote: > When process address packet and counter packet, if the packet contains processing > extended header, it misses to account the extra one byte for header > length calculation, thus returns the wrong packet length. > > To correct the packet length calculation, one possible fixing is simply > to plus extra 1 for extended header, but will spread some duplicate code > in the flows for processing address packet and counter packet. > Alternatively, we can refine the function arm_spe_get_payload() to not > only support short header and allow it to support extended header, and > rely on it for the packet length calculation. > > So this patch refactors function arm_spe_get_payload() with a new > argument 'ext_hdr' for support extended header; the packet processing > flows can invoke this function to unify the packet length calculation. > > Signed-off-by: Leo Yan That looks alright to me. Reviewed-by: Andre Przywara Cheers, Andre > --- > .../arm-spe-decoder/arm-spe-pkt-decoder.c | 34 +++++++------------ > 1 file changed, 12 insertions(+), 22 deletions(-) > > diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c > index 5a8696031e16..4f0aeb62e97b 100644 > --- a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c > +++ b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c > @@ -80,14 +80,15 @@ const char *arm_spe_pkt_name(enum arm_spe_pkt_type type) > (1 << (((val) & SPE_HEADER_SZ_MASK) >> SPE_HEADER_SZ_SHIFT)) > > static int arm_spe_get_payload(const unsigned char *buf, size_t len, > + unsigned char ext_hdr, > struct arm_spe_pkt *packet) > { > - size_t payload_len = PAYLOAD_LEN(buf[0]); > + size_t payload_len = PAYLOAD_LEN(buf[ext_hdr]); > > - if (len < 1 + payload_len) > + if (len < 1 + ext_hdr + payload_len) > return ARM_SPE_NEED_MORE_BYTES; > > - buf++; > + buf += 1 + ext_hdr; > > switch (payload_len) { > case 1: packet->payload = *(uint8_t *)buf; break; > @@ -97,7 +98,7 @@ static int arm_spe_get_payload(const unsigned char *buf, size_t len, > default: return ARM_SPE_BAD_PACKET; > } > > - return 1 + payload_len; > + return 1 + ext_hdr + payload_len; > } > > static int arm_spe_get_pad(struct arm_spe_pkt *packet) > @@ -128,7 +129,7 @@ static int arm_spe_get_timestamp(const unsigned char *buf, size_t len, > struct arm_spe_pkt *packet) > { > packet->type = ARM_SPE_TIMESTAMP; > - return arm_spe_get_payload(buf, len, packet); > + return arm_spe_get_payload(buf, len, 0, packet); > } > > static int arm_spe_get_events(const unsigned char *buf, size_t len, > @@ -143,14 +144,14 @@ static int arm_spe_get_events(const unsigned char *buf, size_t len, > */ > packet->index = PAYLOAD_LEN(buf[0]); > > - return arm_spe_get_payload(buf, len, packet); > + return arm_spe_get_payload(buf, len, 0, packet); > } > > static int arm_spe_get_data_source(const unsigned char *buf, size_t len, > struct arm_spe_pkt *packet) > { > packet->type = ARM_SPE_DATA_SOURCE; > - return arm_spe_get_payload(buf, len, packet); > + return arm_spe_get_payload(buf, len, 0, packet); > } > > static int arm_spe_get_context(const unsigned char *buf, size_t len, > @@ -158,8 +159,7 @@ static int arm_spe_get_context(const unsigned char *buf, size_t len, > { > packet->type = ARM_SPE_CONTEXT; > packet->index = buf[0] & 0x3; > - > - return arm_spe_get_payload(buf, len, packet); > + return arm_spe_get_payload(buf, len, 0, packet); > } > > static int arm_spe_get_op_type(const unsigned char *buf, size_t len, > @@ -167,41 +167,31 @@ static int arm_spe_get_op_type(const unsigned char *buf, size_t len, > { > packet->type = ARM_SPE_OP_TYPE; > packet->index = buf[0] & 0x3; > - return arm_spe_get_payload(buf, len, packet); > + return arm_spe_get_payload(buf, len, 0, packet); > } > > static int arm_spe_get_counter(const unsigned char *buf, size_t len, > const unsigned char ext_hdr, struct arm_spe_pkt *packet) > { > - if (len < 2) > - return ARM_SPE_NEED_MORE_BYTES; > - > packet->type = ARM_SPE_COUNTER; > if (ext_hdr) > packet->index = ((buf[0] & 0x3) << 3) | (buf[1] & 0x7); > else > packet->index = buf[0] & 0x7; > > - packet->payload = le16_to_cpu(*(uint16_t *)(buf + 1)); > - > - return 1 + ext_hdr + 2; > + return arm_spe_get_payload(buf, len, ext_hdr, packet); > } > > static int arm_spe_get_addr(const unsigned char *buf, size_t len, > const unsigned char ext_hdr, struct arm_spe_pkt *packet) > { > - if (len < 8) > - return ARM_SPE_NEED_MORE_BYTES; > - > packet->type = ARM_SPE_ADDRESS; > if (ext_hdr) > packet->index = ((buf[0] & 0x3) << 3) | (buf[1] & 0x7); > else > packet->index = buf[0] & 0x7; > > - memcpy_le64(&packet->payload, buf + 1, 8); > - > - return 1 + ext_hdr + 8; > + return arm_spe_get_payload(buf, len, ext_hdr, packet); > } > > static int arm_spe_do_get_packet(const unsigned char *buf, size_t len, >