From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f176.google.com (mail-pl1-f176.google.com [209.85.214.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8A0771C84C7 for ; Tue, 4 Mar 2025 00:39:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741048796; cv=none; b=A9WSgJianESZX8hKBEI0YdfMN5a1/HD2MQdF6tzdWFDQsYmjbV8yqgGGVzfzM+iNyWUxNr/bbFalsYFt9DjfZQS/R7cS24zxVOQpJPSb9W+lojbKSgCyxwTNwXX6BvuT+wVlm4cXOvtdHUY07fO6MpUBA96JcLk8Q3cjmNU7jOM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741048796; c=relaxed/simple; bh=rkWPmAk7WVKWGqIACfOChkzLOcxrNPRKbBUUx4bSPOs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ddeNn5U5p6LLSipc9r6xTs0fMWoE1KiWewGWgluPwiHlc1WfRbV1/JAMcz9dRQBdrMqJ8OXpwZ842qKgdAqG2c4a49ves/x/lFu52BwsP7w/6sT0oJXvlOfCWG7zhy7KqseXBSarPbkmEMmRm2lyF2Qr/MPko/kzWgpfz9Ohl0o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=qArVyWMM; arc=none smtp.client-ip=209.85.214.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="qArVyWMM" Received: by mail-pl1-f176.google.com with SMTP id d9443c01a7336-22342c56242so72215ad.0 for ; Mon, 03 Mar 2025 16:39:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1741048795; x=1741653595; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=NZZ6RWDnljKub/rNqmhOhGtUl9a9akOzeS+eKL/NSi8=; b=qArVyWMMKL8YstysnALLXFKe/gPNIrW4TqIFc7h10y1oBHcQpbcn02BCNoIYmgIhTV +zSu89EH96kFAL0/hN423fcHpmQ7Yhu16BMDsBq5lOA3iuFwIOZ7c7pgM0JXAiwzIPeh NiGrXZ4oxf53BwmotCbM9EBOEorWKnRGCfUtegitMV9pg5i4EYCvxi/EfcvEHo+rxT0d vqPtDKSaBFdIFq2Pjv/oOjjWf/rpAQLcfFzWNfVfBbqzqe0k1gvS5vDu6ngSkAkk8+Ys pVr9Ilt1PU4zr+b4kW2MxaKjNPrd+uSNdJBRpL+CrRMaqFpTKY8JUIId9Hels6ei85fq kTIQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1741048795; x=1741653595; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=NZZ6RWDnljKub/rNqmhOhGtUl9a9akOzeS+eKL/NSi8=; b=VjJYd9Yeap1KhaePDxW5Rpe0kQcGMpYhPiqj/EHdLGep2a7z81JghPNM2J0jOtZ4fr tQhlfKj/hi/G/s8BZmyWFUViYZhPHi3n1Tg8NYGUrK8FNh8YW+ZBx5shhcGTzGY5ciUd YwZa9xBfqLt8JNqk8O4pSSlmDm/VhH6dZWCYJP1M8DpnXHutkAwmaHkdbU55zTZgH1Yc Mx2pPfgY9q+vhWCtV0lbmrAT+Me75BqvTj9ssj4bDKB6u5N4hw3MNnf3lN6EQMoIMyUU 9ElWP8qsQRrKkNIXYg576dPKaAlwfhteTfOVTbwjyzwe9qsHJvFoPWl8SOTsU54E8+xa kSsA== X-Gm-Message-State: AOJu0YxZjgzpoIgvaitHOMsNIsxmtwANMF03XoZ4FaTbHeFAsuqltrxP QnyKfPEf/Lo4bm5n3lmNnCSrS+y6wu4mHjivBvrruC0AHsw7DzZNUlbcaPaFZA1hiT0oQWTsozb jVw== X-Gm-Gg: ASbGncsCGQ94LZewK8FKAuDR+b26ikv+AZpvlGfRC02XHy2cD8axyZIx1z2cXvLxfkn rp9GBJ1xXLkOGlphwhq/eVlj76HTnSdvl513iBF7aAsUo+4hNd541Vyi9t3YxtQsoVfkrlZzRH7 J4pZ7TpvcERUcdYOWTURHSf0tN6y0wGJYsjI7VCYCDPSrYW0fukJIOhlZGiAhQbK+OTa05HpWyE gLeSrBCSDeYmqDR9FmiJmeIjwjghsx6aKHAvKPd0B/6YW/mZTpu/uyLjydCilGOmZILOU7VoxCu NEdZ5ypEC9HkYK4KeN/7AJFpLSK6+mldkeWqJxcNz7Bzgzb9F8kY+d5rW15C5EC7HkcBwTtIQlU HlN6Yb7g= X-Google-Smtp-Source: AGHT+IEFZMvKPvqJtn6porx/jOyYtLyQRQGPPfM3zCCktwuBu79Q8Ew7WkeXkukdVZEY0NkgznAoKg== X-Received: by 2002:a17:902:ea05:b0:216:48d4:b3a8 with SMTP id d9443c01a7336-223d9e0df5cmr1199935ad.16.1741048794489; Mon, 03 Mar 2025 16:39:54 -0800 (PST) Received: from google.com (147.141.16.34.bc.googleusercontent.com. [34.16.141.147]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-aee90c7e519sm6971619a12.61.2025.03.03.16.39.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Mar 2025 16:39:53 -0800 (PST) Date: Tue, 4 Mar 2025 00:39:48 +0000 From: Peilin Ye To: Alexei Starovoitov Cc: bpf , linux-arm-kernel , bpf@ietf.org, Alexei Starovoitov , Xu Kuohai , Eduard Zingerman , David Vernet , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Jonathan Corbet , "Paul E. McKenney" , Puranjay Mohan , Ilya Leoshkevich , Heiko Carstens , Vasily Gorbik , Catalin Marinas , Will Deacon , Quentin Monnet , Mykola Lysenko , Shuah Khan , Ihor Solodrai , Yingchi Long , Josh Don , Barret Rhoden , Neel Natu , Benjamin Segall , LKML Subject: Re: [PATCH bpf-next v5 1/6] bpf: Introduce load-acquire and store-release instructions Message-ID: References: Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Hi Alexei, On Mon, Mar 03, 2025 at 04:24:12PM -0800, Alexei Starovoitov wrote: > > switch (insn->imm) { > > @@ -7780,6 +7813,24 @@ static int check_atomic(struct bpf_verifier_env *env, struct bpf_insn *insn) > > case BPF_XCHG: > > case BPF_CMPXCHG: > > return check_atomic_rmw(env, insn); > > + case BPF_LOAD_ACQ: > > +#ifndef CONFIG_64BIT > > + if (BPF_SIZE(insn->code) == BPF_DW) { > > + verbose(env, > > + "64-bit load-acquires are only supported on 64-bit arches\n"); > > + return -EOPNOTSUPP; > > + } > > +#endif > > Your earlier proposal of: > if (BPF_SIZE(insn->code) == BPF_DW && BITS_PER_LONG != 64) { > > was cleaner. > Why did you pick ifndef ? Likely overthinking, but I wanted to avoid this check at all for 64-bit arches, so it's just a little bit faster. Should I change it back to checking BITS_PER_LONG ? Thanks, Peilin Ye