From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C701A1E572F for ; Mon, 21 Oct 2024 11:20:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729509653; cv=none; b=QoWDIcn+DAKCO6L1hIm4pdv7y6orL93D1s4bKleR/0xJijtddEZYrP2p+EnqonlGsuVWyx+4/PNwOHbwDtsPb/AuqSeRuYNRrPh3W9qoYwrTDSD2Dm+X12aU3+ujxzp4qeJxngWezILShHV27UxNcq7PyhtnfI7NeZzkTqXY5Bo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729509653; c=relaxed/simple; bh=vN1ylj+X91hQZw4H17XL5HLnuy4ALKIQAm1oA5MM2rA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YMmAy3HmYNoBtXB0PcSp7oXSR0gQOsdW2LkcT6UfxSN2D7i0iL7wYpsu2BElP3ubgL97RaUnSOCWh4DQfvJjUtyeiDPPvDZn3mxoSBqtkCWB2OiaodFwS5bLa6o/0aTmZ2f8VdoIDzY3PicqtGhwaHsDVsXiCJkvtmB8VSAPdiI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=LZfS4iPL; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LZfS4iPL" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1729509650; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5EJq3nTCY2846K0vo9vaCnqoyl72A9YpQztvsfdIGoY=; b=LZfS4iPLnPwXhszaGgO6nJTNGrL2cKd5yBH+39LUsgokaWhh4HtxDSZwr1mlp/7FlIEVXt gTfy2ewLMuOb8i4FDdlBfo2XDa4/DiTIq+H/jHEhm3v+acH9GWuJ742jbaeFlhAgS9sXQH 8xDLWkf8PnOshIKVEMYxQg8d6u58b2U= Received: from mail-ua1-f72.google.com (mail-ua1-f72.google.com [209.85.222.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-228-5lil7ap-PaWv4OiU0i18Bw-1; Mon, 21 Oct 2024 07:20:48 -0400 X-MC-Unique: 5lil7ap-PaWv4OiU0i18Bw-1 Received: by mail-ua1-f72.google.com with SMTP id a1e0cc1a2514c-850069b5c2dso594269241.1 for ; Mon, 21 Oct 2024 04:20:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729509648; x=1730114448; h=content-transfer-encoding:in-reply-to:content-language:from :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=5EJq3nTCY2846K0vo9vaCnqoyl72A9YpQztvsfdIGoY=; b=BkihX03GYMeJcmN7dPQxKzemIFQuhdW6wjdrzYy5BEq2i6bC7x5qYQCRo1ELhw7qK/ Z1AY0uX6O7787vikHao6OIF4xPQh1367pYwTLU0PfFoaZ2xm+6MVUlnT2xxQ1xsX2HAW +/V0cAXkCx92nDtA1bWRDKLbcPHiBxyRgbyhleBhy7BKSHaR9rdgfR5vspG+cmpmkTo5 vi5+yM3N37my0wU9ExJYHgcvx0F9yWnLnNCz7HEkyx7DXSHRtDniw1lBfmcdYun+GCrG duCAUyclieQot8eKiF3bsMZie+n2FW+Aryupevc09jMvEG6cE7rDEJE/lv3Qid0bTEnt 0Jww== X-Forwarded-Encrypted: i=1; AJvYcCW/tQumkYCoEsnacFxni2WTSH3Z1c6Z+V1VZtUyGq0uRrvg9Y63UnPMmsHnU9t8W6iFw2B5Ga42r1mSHkdOI3M=@vger.kernel.org X-Gm-Message-State: AOJu0YzC0C9oF6lqaeCx9Lt5NOCEOViIkOwZYcqH47TJ+mwuUwBnsdZY XYp8u2BBLC9lGnSLx0WxSW6qvmb+P0ak5IizEOPwGDD4mldqAq8qasyqLIYOZJ0cZ0mGDyKz+xR icdAXGWeliwW9Nqu07ZQBu/QbDjTYi3zwl2YoCDeGF6HfVFuoQ/KOTwUROxfNuBtYCw== X-Received: by 2002:a05:6102:ccb:b0:4a3:ce37:9137 with SMTP id ada2fe7eead31-4a5d6b080cbmr9475729137.13.1729509648301; Mon, 21 Oct 2024 04:20:48 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEeyi/HIFqi2HtXCMmpe1qAaPmojvVF0iexyAfT2ooED6UKyLdMATTFLlU05hPn3kNpW2Vngw== X-Received: by 2002:a05:6102:ccb:b0:4a3:ce37:9137 with SMTP id ada2fe7eead31-4a5d6b080cbmr9475690137.13.1729509647916; Mon, 21 Oct 2024 04:20:47 -0700 (PDT) Received: from ?IPV6:2a09:80c0:192:0:36d3:2b96:a142:a05b? ([2a09:80c0:192:0:36d3:2b96:a142:a05b]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-460d3c62e9esm16564851cf.27.2024.10.21.04.20.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 21 Oct 2024 04:20:47 -0700 (PDT) Message-ID: <7213ebbd-49d1-422d-84f2-14b48a14ed82@redhat.com> Date: Mon, 21 Oct 2024 13:20:44 +0200 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] selftests: kvm: Adds a judgment on the return value To: Liu Jing , borntraeger@linux.ibm.com Cc: frankja@linux.ibm.com, imbrenda@linux.ibm.com, pbonzini@redhat.com, shuah@kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org References: <20241021100644.3591-1-liujing@cmss.chinamobile.com> From: David Hildenbrand Content-Language: en-US In-Reply-To: <20241021100644.3591-1-liujing@cmss.chinamobile.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Am 21.10.24 um 12:06 schrieb Liu Jing: > The global variable errno is not recommended to be assigned, Just curious: from where is that information? Reading the man page: "errno is defined by the ISO C standard to be a modifiable lvalue of type int, and must not be explicitly declared; errno may be a macro. errno is thread-local; setting it in one thread does not affect its value in any other thread." Paired with "For some system calls and library functions (e.g., getpriority(2)), -1 is a valid return on success. In such cases, a successful return can be distinguished from an error return by setting errno to zero before the call" Not objecting that relying on the rc looks cleaner. > and rc in the function does not check its return value, so it is fixed > > Signed-off-by: Liu Jing > --- > tools/testing/selftests/kvm/s390x/cmma_test.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/kvm/s390x/cmma_test.c b/tools/testing/selftests/kvm/s390x/cmma_test.c > index e32dd59703a0..c59c21f28bbd 100644 > --- a/tools/testing/selftests/kvm/s390x/cmma_test.c > +++ b/tools/testing/selftests/kvm/s390x/cmma_test.c > @@ -210,7 +210,7 @@ static int vm_get_cmma_bits(struct kvm_vm *vm, u64 flags, int *errno_out) > struct kvm_s390_cmma_log args; > int rc; > > - errno = 0; > + *errno_out = 0; > > args = (struct kvm_s390_cmma_log){ > .start_gfn = 0, > @@ -219,8 +219,10 @@ static int vm_get_cmma_bits(struct kvm_vm *vm, u64 flags, int *errno_out) > .values = (__u64)&cmma_value_buf[0] > }; > rc = __vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, &args); > + if (rc < 0) { > + *errno_out = errno; > + } > if (rc < 0) *errno_out = errno; -- Cheers, David / dhildenb