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=-11.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 58294C433DF for ; Mon, 12 Oct 2020 00:30:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE0E42087D for ; Mon, 12 Oct 2020 00:30:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="BGn5UdAR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727093AbgJLAaH (ORCPT ); Sun, 11 Oct 2020 20:30:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726735AbgJLAaG (ORCPT ); Sun, 11 Oct 2020 20:30:06 -0400 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88B76C0613CE for ; Sun, 11 Oct 2020 17:30:06 -0700 (PDT) Received: by mail-pf1-x441.google.com with SMTP id e10so11957138pfj.1 for ; Sun, 11 Oct 2020 17:30:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=Dzz8AtvP56fc2S3kjLJ9Ac6AwJBJP5SSxCgOVVjjLk8=; b=BGn5UdARxo35j3vQCgHppGYhBJdSz00oP83S0KvyfXEW+VchoqBVc0qyTFAYCjispw A2hAn68PH6O4ndVD6jVl2/+PIXKo3nC0ymUQL1pRYBOGntzdc2OLYX07OMWLW5AlGQ3n 4yK3N1ChJ6OhT/UYqO+mJJajimpRRY3KPJbekXzktv4ZO8gKXvwn1rN6On/EnNBwR+Fj guoLeqA/f9oYkrANHsY7BIaP9MnEPUFRdTBs7rZbOq0EkX5++AJC+Z533UmGgh38MBPl ineljtrRMmM/vrlf0SxTFLfUrbeq+oHziedgfFV7kE7UYJ1ZMpFZseGu4PTG/5Dosito BxiA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=Dzz8AtvP56fc2S3kjLJ9Ac6AwJBJP5SSxCgOVVjjLk8=; b=hA2seJ9euOn0kvygCFIkHErl6yiuVpkX8BXhSHQBY45/r4V820ULSG9e+gXgWJV6t5 RZZdYMg8LSHA4SPOMl7wFP1V5wo8P7eHVnw+PM7wAAVe12pgszXhdf2rjAN1sxr9sQ1Z SI7dBzgkEMiQj7NmxjB08mELYIq8DQ7++fCoYCjx/uT3d/xy9ss4JZl0PKOhQjpZ2Wzg YIR0+2QLVVhAwBQMKt0nbSmb1cREu7ibS/phKzqtV+QL4t6L06kJvXklK3oqKPg7ZSz0 0jCva+L+tDG2mekN0Az3beespgKQ76Cwf9acuB70xqcl+ugGq+SOvMVtQHseenX2SA3I I1Cg== X-Gm-Message-State: AOAM532Yj/QDhB6Be51Bau9L4yp9N4k3A0xCc/YzSC2iTRB1k8r346KM ps7qgQZG8/jrJJzPNf5qdvWtj9y9QOJ8Vjum X-Google-Smtp-Source: ABdhPJwnBKRL/q0Kpimfr4MZe3PL2tiBkk80j7hXFgEXIwMGzyUPKXEeTd4xNh3vJ9MKjekWkJ2hMA== X-Received: by 2002:a17:90b:4b90:: with SMTP id lr16mr17538311pjb.0.1602462605805; Sun, 11 Oct 2020 17:30:05 -0700 (PDT) Received: from leoy-ThinkPad-X240s ([64.120.119.108]) by smtp.gmail.com with ESMTPSA id m22sm16816322pfk.214.2020.10.11.17.30.00 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Sun, 11 Oct 2020 17:30:05 -0700 (PDT) Date: Mon, 12 Oct 2020 08:29:58 +0800 From: Leo Yan To: =?iso-8859-1?Q?Andr=E9?= Przywara Cc: 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 Subject: Re: [PATCH v2 05/14] perf arm-spe: Refactor printing string to buffer Message-ID: <20201012002958.GC15194@leoy-ThinkPad-X240s> References: <20200929133917.9224-1-leo.yan@linaro.org> <20200929133917.9224-6-leo.yan@linaro.org> <6d565f8a-e573-9b9b-b0b4-43e542dd568c@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <6d565f8a-e573-9b9b-b0b4-43e542dd568c@arm.com> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 08, 2020 at 02:46:06PM +0100, André Przywara wrote: > On 29/09/2020 14:39, Leo Yan wrote: > > Hi, > > > When outputs strings to the decoding buffer with function snprintf(), > > SPE decoder needs to detects if any error returns from snprintf() and if > > so needs to directly bail out. If snprintf() returns success, it needs > > to update buffer pointer and reduce the buffer length so can continue to > > output the next string into the consequent memory space. > > > > This complex logics are spreading in the function arm_spe_pkt_desc() so > > there has many duplicate codes for handling error detecting, increment > > buffer pointer and decrement buffer size. > > > > To avoid the duplicate code, this patch introduces a new helper function > > arm_spe_pkt_snprintf() which is used to wrap up the complex logics, and > > the caller arm_spe_pkt_desc() will call it and simply check the returns > > value. > > > > This patch also moves the variable 'blen' as the function's local > > variable, this allows to remove the unnecessary braces and improve the > > readability. > > Ah, many thanks for tackling this, I wondered about those code > duplications and missing error handling already. > > So I tried some sed pattern on the "old" part of the patch, to get to > the new format and spot any differences apart from mechanically changing > "snprintf(buf, buf_len," to "arm_spe_pkt_snprintf(&buf, &blen,". > See below. > > > > > Suggested-by: Dave Martin > > Signed-off-by: Leo Yan > > Very nice cleanup! If you can address this one '"%s", name' comment > below, then: > > Reviewed-by: Andre Przywara > > > > --- > > .../arm-spe-decoder/arm-spe-pkt-decoder.c | 247 ++++++++++-------- > > 1 file changed, 135 insertions(+), 112 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 4f0aeb62e97b..96b717a19163 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 > > @@ -9,6 +9,7 @@ > > #include > > #include > > #include > > +#include > > > > #include "arm-spe-pkt-decoder.h" > > > > @@ -256,192 +257,214 @@ int arm_spe_get_packet(const unsigned char *buf, size_t len, > > return ret; > > } > > > > +static int arm_spe_pkt_snprintf(char **buf_p, size_t *blen, > > + const char *fmt, ...) > > +{ > > + va_list ap; > > + int ret; > > + > > + va_start(ap, fmt); > > + ret = vsnprintf(*buf_p, *blen, fmt, ap); > > + va_end(ap); > > + > > + if (ret < 0) > > + return ret; > > + > > + *buf_p += ret; > > + *blen -= ret; > > + return ret; > > +} > > + > > int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf, > > size_t buf_len) > > { > > int ret, ns, el, idx = packet->index; > > unsigned long long payload = packet->payload; > > const char *name = arm_spe_pkt_name(packet->type); > > + size_t blen = buf_len; > > > > switch (packet->type) { > > case ARM_SPE_BAD: > > case ARM_SPE_PAD: > > case ARM_SPE_END: > > - return snprintf(buf, buf_len, "%s", name); > > - case ARM_SPE_EVENTS: { > > - size_t blen = buf_len; > > - > > - ret = 0; > > - ret = snprintf(buf, buf_len, "EV"); > > - buf += ret; > > - blen -= ret; > > + return arm_spe_pkt_snprintf(&buf, &blen, name); > > Isn't it considered safer to use '..., "%s", name)', because that would > handle percent signs in "name" correctly? > Not really an issue in the current code, but good style, I believe. Good point. '..., "%s", name)' format is more reliable, will change to use it. > > + case ARM_SPE_EVENTS: > > + ret = arm_spe_pkt_snprintf(&buf, &blen, "EV"); > > + if (ret < 0) > > + return ret; > > + > > if (payload & 0x1) { > > - ret = snprintf(buf, buf_len, " EXCEPTION-GEN"); > > So this was actually a bug before, right? Because "buf" does no longer > have buf_len bytes available at this point, it should have been blen > here already. Which gets fixed with all your changes! Exactly, I will update the commit log so can give more explicit info. Thanks a lot, Leo > Thanks! > Andre > > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " EXCEPTION-GEN"); > > + if (ret < 0) > > + return ret; > > } > > if (payload & 0x2) { > > - ret = snprintf(buf, buf_len, " RETIRED"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " RETIRED"); > > + if (ret < 0) > > + return ret; > > } > > if (payload & 0x4) { > > - ret = snprintf(buf, buf_len, " L1D-ACCESS"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " L1D-ACCESS"); > > + if (ret < 0) > > + return ret; > > } > > if (payload & 0x8) { > > - ret = snprintf(buf, buf_len, " L1D-REFILL"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " L1D-REFILL"); > > + if (ret < 0) > > + return ret; > > } > > if (payload & 0x10) { > > - ret = snprintf(buf, buf_len, " TLB-ACCESS"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " TLB-ACCESS"); > > + if (ret < 0) > > + return ret; > > } > > if (payload & 0x20) { > > - ret = snprintf(buf, buf_len, " TLB-REFILL"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " TLB-REFILL"); > > + if (ret < 0) > > + return ret; > > } > > if (payload & 0x40) { > > - ret = snprintf(buf, buf_len, " NOT-TAKEN"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " NOT-TAKEN"); > > + if (ret < 0) > > + return ret; > > } > > if (payload & 0x80) { > > - ret = snprintf(buf, buf_len, " MISPRED"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " MISPRED"); > > + if (ret < 0) > > + return ret; > > } > > if (idx > 1) { > > if (payload & 0x100) { > > - ret = snprintf(buf, buf_len, " LLC-ACCESS"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " LLC-ACCESS"); > > + if (ret < 0) > > + return ret; > > } > > if (payload & 0x200) { > > - ret = snprintf(buf, buf_len, " LLC-REFILL"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " LLC-REFILL"); > > + if (ret < 0) > > + return ret; > > } > > if (payload & 0x400) { > > - ret = snprintf(buf, buf_len, " REMOTE-ACCESS"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " REMOTE-ACCESS"); > > + if (ret < 0) > > + return ret; > > } > > } > > - if (ret < 0) > > - return ret; > > - blen -= ret; > > return buf_len - blen; > > - } > > + > > case ARM_SPE_OP_TYPE: > > switch (idx) { > > - case 0: return snprintf(buf, buf_len, "%s", payload & 0x1 ? > > - "COND-SELECT" : "INSN-OTHER"); > > - case 1: { > > - size_t blen = buf_len; > > - > > - if (payload & 0x1) > > - ret = snprintf(buf, buf_len, "ST"); > > - else > > - ret = snprintf(buf, buf_len, "LD"); > > - buf += ret; > > - blen -= ret; > > + case 0: > > + return arm_spe_pkt_snprintf(&buf, &blen, > > + payload & 0x1 ? "COND-SELECT" : "INSN-OTHER"); > > + case 1: > > + ret = arm_spe_pkt_snprintf(&buf, &blen, > > + payload & 0x1 ? "ST" : "LD"); > > + if (ret < 0) > > + return ret; > > + > > if (payload & 0x2) { > > if (payload & 0x4) { > > - ret = snprintf(buf, buf_len, " AT"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " AT"); > > + if (ret < 0) > > + return ret; > > } > > if (payload & 0x8) { > > - ret = snprintf(buf, buf_len, " EXCL"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " EXCL"); > > + if (ret < 0) > > + return ret; > > } > > if (payload & 0x10) { > > - ret = snprintf(buf, buf_len, " AR"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " AR"); > > + if (ret < 0) > > + return ret; > > } > > } else if (payload & 0x4) { > > - ret = snprintf(buf, buf_len, " SIMD-FP"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " SIMD-FP"); > > + if (ret < 0) > > + return ret; > > } > > + > > + return buf_len - blen; > > + > > + case 2: > > + ret = arm_spe_pkt_snprintf(&buf, &blen, "B"); > > if (ret < 0) > > return ret; > > - blen -= ret; > > - return buf_len - blen; > > - } > > - case 2: { > > - size_t blen = buf_len; > > > > - ret = snprintf(buf, buf_len, "B"); > > - buf += ret; > > - blen -= ret; > > if (payload & 0x1) { > > - ret = snprintf(buf, buf_len, " COND"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " COND"); > > + if (ret < 0) > > + return ret; > > } > > if (payload & 0x2) { > > - ret = snprintf(buf, buf_len, " IND"); > > - buf += ret; > > - blen -= ret; > > + ret = arm_spe_pkt_snprintf(&buf, &blen, " IND"); > > + if (ret < 0) > > + return ret; > > } > > - if (ret < 0) > > - return ret; > > - blen -= ret; > > + > > return buf_len - blen; > > - } > > - default: return 0; > > + > > + default: > > + return 0; > > } > > case ARM_SPE_DATA_SOURCE: > > case ARM_SPE_TIMESTAMP: > > - return snprintf(buf, buf_len, "%s %lld", name, payload); > > + return arm_spe_pkt_snprintf(&buf, &blen, "%s %lld", name, payload); > > case ARM_SPE_ADDRESS: > > switch (idx) { > > case 0: > > case 1: ns = !!(packet->payload & NS_FLAG); > > el = (packet->payload & EL_FLAG) >> 61; > > payload &= ~(0xffULL << 56); > > - return snprintf(buf, buf_len, "%s 0x%llx el%d ns=%d", > > + return arm_spe_pkt_snprintf(&buf, &blen, > > + "%s 0x%llx el%d ns=%d", > > (idx == 1) ? "TGT" : "PC", payload, el, ns); > > - case 2: return snprintf(buf, buf_len, "VA 0x%llx", payload); > > + case 2: > > + return arm_spe_pkt_snprintf(&buf, &blen, > > + "VA 0x%llx", payload); > > case 3: ns = !!(packet->payload & NS_FLAG); > > payload &= ~(0xffULL << 56); > > - return snprintf(buf, buf_len, "PA 0x%llx ns=%d", > > - payload, ns); > > - default: return 0; > > + return arm_spe_pkt_snprintf(&buf, &blen, > > + "PA 0x%llx ns=%d", payload, ns); > > + default: > > + return 0; > > } > > case ARM_SPE_CONTEXT: > > - return snprintf(buf, buf_len, "%s 0x%lx el%d", name, > > - (unsigned long)payload, idx + 1); > > - case ARM_SPE_COUNTER: { > > - size_t blen = buf_len; > > - > > - ret = snprintf(buf, buf_len, "%s %d ", name, > > - (unsigned short)payload); > > - buf += ret; > > - blen -= ret; > > - switch (idx) { > > - case 0: ret = snprintf(buf, buf_len, "TOT"); break; > > - case 1: ret = snprintf(buf, buf_len, "ISSUE"); break; > > - case 2: ret = snprintf(buf, buf_len, "XLAT"); break; > > - default: ret = 0; > > - } > > + return arm_spe_pkt_snprintf(&buf, &blen, "%s 0x%lx el%d", > > + name, (unsigned long)payload, idx + 1); > > + case ARM_SPE_COUNTER: > > + ret = arm_spe_pkt_snprintf(&buf, &blen, "%s %d ", name, > > + (unsigned short)payload); > > if (ret < 0) > > return ret; > > - blen -= ret; > > + > > + switch (idx) { > > + case 0: > > + ret = arm_spe_pkt_snprintf(&buf, &blen, "TOT"); > > + if (ret < 0) > > + return ret; > > + break; > > + case 1: > > + ret = arm_spe_pkt_snprintf(&buf, &blen, "ISSUE"); > > + if (ret < 0) > > + return ret; > > + break; > > + case 2: > > + ret = arm_spe_pkt_snprintf(&buf, &blen, "XLAT"); > > + if (ret < 0) > > + return ret; > > + break; > > + default: > > + break; > > + } > > + > > return buf_len - blen; > > - } > > + > > default: > > break; > > } > > > > - return snprintf(buf, buf_len, "%s 0x%llx (%d)", > > - name, payload, packet->index); > > + return arm_spe_pkt_snprintf(&buf, &blen, "%s 0x%llx (%d)", > > + name, payload, packet->index); > > } > > >