From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f174.google.com (mail-pg1-f174.google.com [209.85.215.174]) (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 1995C1E890 for ; Mon, 15 Jul 2024 23:55:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721087750; cv=none; b=RtHFhkMzqRdyyfScvZ3jE/KEdHCl4Ox75yegI3oFCUU/9aRhDdFu/ZhDHQDq80WX8MDNClY/gBmII3QpywDXAwtF1IKKvfuMjm2YGfy0+FGi8pXXkG8ptY0MNXoNOfZpX36VBBAw2etJtfDlQP1Xpr4dRRVZxnpbjzP8mynWIC8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721087750; c=relaxed/simple; bh=Ie+GpugXhMedyalTyQuUCMwpFXJ5/yLRZ9OJEGI7WoU=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=lea2vmVJdz6ryCQdZM6MPSs34GFP/ArCTCq9m88Ci8b/ggxXDP3HGtXEcY2IifjrlnAVyKBKbZs617A5MwlUcqR+E6Sg1DZkK0poZoLyMPP5ouoNuMQsDVcYtEVjWHB9tTLSRQJChKAfrmYKRAOA2fnLdUl8JBoogq5XJ5ExcFI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=e745A8uz; arc=none smtp.client-ip=209.85.215.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="e745A8uz" Received: by mail-pg1-f174.google.com with SMTP id 41be03b00d2f7-795d2aa4ba4so172325a12.3 for ; Mon, 15 Jul 2024 16:55:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1721087748; x=1721692548; darn=vger.kernel.org; h=mime-version:user-agent:content-transfer-encoding:references :in-reply-to:date:cc:to:from:subject:message-id:from:to:cc:subject :date:message-id:reply-to; bh=oriqLV0ynz58BFDLv4p0WSUWoGsw4FrgoSPv9lgBI5I=; b=e745A8uzCQ/f+CTWzc7NB4t3qSBIOROvyPmF78RqDgNH0IsudzVFvdvkV4VuQ82Sef YarJWZ7vNAKQgvkdJvS9MyJrWFY1U/6gYX/Jz5Al3RXtNAunOhsut1IHfOkJdK04O7xw O0U8IwebAKFH33HmV1ggq4bqLvMTEDBC9ORzpvZuQQDmWOVygRXHneCLy2swPZH6ecbs AWnFiS8sDl6lgs66o0P0rxJ9IeW++Na7+pPBpZKfKNr29vIpsv1StzmzbKEcLGSzZ4oP UdDke74RwJNCcdx7IUFVLXTe4fNT8AgBQ/vvDal6CTqVb7n71D0zNFkom+mGecDaUd/0 k9Kg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721087748; x=1721692548; h=mime-version:user-agent:content-transfer-encoding:references :in-reply-to:date:cc:to:from:subject:message-id:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=oriqLV0ynz58BFDLv4p0WSUWoGsw4FrgoSPv9lgBI5I=; b=sA/T/IAlKy5T6QIa+uq8AZZwYUJeH0vmj6X1Vwd9F1S+Yp1nAwgLzM1/VbG02cnT5Y Oe8xImz+hs3LWXV2N2BnfQI0NWAvexuX5amavClxTcgbHjve7+D3d+6kq5HVWYPhUSmM iswEcJkFxLg6fM5cLFjq/A6egFWE/trljc+1zO7fsv4yNZ4p/bIPl1smA4V12YuD3nFV 1P7spZQei8Tp9pUt67oCUa0ueqGK2kIBiv1isi+al8xHa5JIoZF+v7OqSWo2Je2lAPYs owic5ZbnYfcJRNNdU6eaeTGFvk9xdvQEHqKi6Cl6dDB5dxfv90/rLzZFKJtixuiC+xw0 0Msg== X-Forwarded-Encrypted: i=1; AJvYcCVdG7mPo8AgPGRlsnhCW6OADF0AcYw3DbcAO9zuwA83H9FiYOAY3pAF5f81+vUran2Db8ma8a2QsH3P158dMOi3Tr7n X-Gm-Message-State: AOJu0YyHfG1lREOfxQFGKnSJYr/5zQlURxXYTBt++B+Yt4BtJHppLynp 4hTnfeIc/IP/yNJB5W6hMG3ejYcjUvRlSWmPfMOeVfJ6xrvfCeqw X-Google-Smtp-Source: AGHT+IHkh1yzDOemy+xWek82YAOW6mjaN0uLkZ/NHkHmcvIlp2CSqWo257HBW3mgShGTtwHReqA51g== X-Received: by 2002:a05:6a21:32a3:b0:1bd:1d6e:d444 with SMTP id adf61e73a8af0-1c3f12037c1mr611475637.2.1721087748193; Mon, 15 Jul 2024 16:55:48 -0700 (PDT) Received: from [192.168.0.31] ([38.34.87.7]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1fc0bba45ccsm46443005ad.82.2024.07.15.16.55.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Jul 2024 16:55:47 -0700 (PDT) Message-ID: <3594134da3dd50a5e7fca62d9843c47a8b47ce9a.camel@gmail.com> Subject: Re: [PATCH bpf-next v3 1/2] bpf: Get better reg range with ldsx and 32bit compare From: Eduard Zingerman To: Yonghong Song , bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , kernel-team@fb.com, Martin KaFai Lau Date: Mon, 15 Jul 2024 16:55:42 -0700 In-Reply-To: <20240712234359.287698-1-yonghong.song@linux.dev> References: <20240712234359.287698-1-yonghong.song@linux.dev> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.44.4-0ubuntu2 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Fri, 2024-07-12 at 16:43 -0700, Yonghong Song wrote: [...] > This patch fixed the issue by adding additional register deduction after = 32-bit compare > insn. If the signed 32-bit register range is non-negative then 64-bit smi= n is > in range of [S32_MIN, S32_MAX], then the actual 64-bit smin/smax should b= e the same > as 32-bit smin32/smax32. [...] Acked-by: Eduard Zingerman [...] > + * Now, suppose that register range is in fact tighter: > + * [0xffff_ffff_8000_0000, 0x0000_0000_ffff_ffff] (R) > + * Also suppose that it's 32-bit range is positive, > + * meaning that lower 32-bits of the full 64-bit register > + * are in the range: > + * [0x0000_0000, 0x7fff_ffff] (W) > + * > + * It this happens, then any value in a range: ^^ Sorry, one more typo, should be "If". Maybe could be changed when the patch would be applied. [...]