From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f42.google.com (mail-wm1-f42.google.com [209.85.128.42]) (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 05EBC10F3; Fri, 15 Dec 2023 01:43:35 +0000 (UTC) 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="RPJ8PLMA" Received: by mail-wm1-f42.google.com with SMTP id 5b1f17b1804b1-40c2c65e6aaso1974805e9.2; Thu, 14 Dec 2023 17:43:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1702604614; x=1703209414; darn=vger.kernel.org; h=mime-version:user-agent:content-transfer-encoding:autocrypt :references:in-reply-to:date:cc:to:from:subject:message-id:from:to :cc:subject:date:message-id:reply-to; bh=ZPXPBhj6r6wn/s7iUr6Ov+9BGjRNtkcDIxrWuGzYqqU=; b=RPJ8PLMAbBBFLXfhdNL/hD+S1YytfI9setztdjqgghfH4hCHL7rwAGWSzd0x/wiuFB Zr9D04NK+L/Rqqyb0/ShhhU4wgA7Koii5vaMmMl+6UfdSv1NW5p/gk1gdARneZZw38S1 L02bynZhEyQ0cQ/XoIQgxI9wGgoWLCv5OCN22TBax0ARRGCOmwo1+X4Sv/qAAv6Wop+I bckt045hU1ZgA9Y/XeXYfyvD0d7PDabxgLbbdz7JrTe91XgFqWqS+hKF2VLdQ1b665gz qjEZI3ztMO25Bf4FYl3l5WTEeo/pXX3jzFDrYkq7GAv/3W59ZXfJNVCiwLYeiUJEsDam N1gw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702604614; x=1703209414; h=mime-version:user-agent:content-transfer-encoding:autocrypt :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=ZPXPBhj6r6wn/s7iUr6Ov+9BGjRNtkcDIxrWuGzYqqU=; b=Uj3L5Yfd4EwLg6DOsObRHIDPOy4A5CWzFD3yrRK+CJT8V1FPnOWUEIcF0bUga0b6uM FLR4VCYiy3a7/jK8UG7/uuiYUPn/hhfUnJZkn5/3F7qnXxRo3RoUSsP0b0ccP5lRk3k+ 4RCT+EwkYIIO9d9JXRl5XAHe7pwfay1Oa58Jbj1kdw9DvkHvzsTqKHe4Q+8xyY84bQKW xMhaa/klsDjWFIeukTBoSsKZUHVaOoUADc4OBhrwm2AibUE8FZraL77nzrGIneyRYgW2 cdPu02A+HAH4rvwD+7YRdz8mQgfDdk5z6pnyI/Dim83Oz9Efpd8hfR+bjjl7ApOI0Czi XkMQ== X-Gm-Message-State: AOJu0YzvH4m9GjNxfOS+qIntgoWn/1my6vZGTkZgB2GSDwGaaBaAnmsS /+5xgHwNN/4eRSZ2vcyktu4= X-Google-Smtp-Source: AGHT+IGHbvX/KwnnFSDijk7FhPD1SJcKVFFkFn1IWOSVYXK88SCVtOeGj0OJgpawZ/uIv8bh4y5CIQ== X-Received: by 2002:a05:600c:1913:b0:40b:5e21:bde8 with SMTP id j19-20020a05600c191300b0040b5e21bde8mr5092782wmq.119.1702604614043; Thu, 14 Dec 2023 17:43:34 -0800 (PST) Received: from [192.168.1.95] (host-176-36-0-241.b024.la.net.ua. [176.36.0.241]) by smtp.gmail.com with ESMTPSA id p18-20020a5d6392000000b003333a216682sm17313271wru.97.2023.12.14.17.43.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Dec 2023 17:43:33 -0800 (PST) Message-ID: Subject: Re: [Bug Report] bpf: incorrectly pruning runtime execution path From: Eduard Zingerman To: Andrii Nakryiko Cc: Hao Sun , Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , bpf , Linux Kernel Mailing List Date: Fri, 15 Dec 2023 03:43:32 +0200 In-Reply-To: <2b49b96de9f8a1cd6d78cc5aebe7c35776cd2c19.camel@gmail.com> References: <480a5cfefc23446f7c82c5b87eef6306364132b9.camel@gmail.com> <917DAD9F-8697-45B8-8890-D33393F6CDF1@gmail.com> <9dee19c7d39795242c15b2f7aa56fb4a6c3ebffa.camel@gmail.com> <73d021e3f77161668aae833e478b210ed5cd2f4d.camel@gmail.com> <526d4ac8f6788d3323d29fdbad0e0e5d09a534db.camel@gmail.com> <2b49b96de9f8a1cd6d78cc5aebe7c35776cd2c19.camel@gmail.com> Autocrypt: addr=eddyz87@gmail.com; prefer-encrypt=mutual; keydata=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 nYzhLWGcczc6J71q1Dje0l5vIPaSFOgwmWD4DA+WvuxM/shH4rtWeodbv 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 t1iq+gsfnXbPz5AnS598ScZI1oP7OrPSFJkt/z4acEbOQDQs8aUqrd46PV jsdqGvKnXZxzylux29UTNby4jTlz9pNJM+wPrDRmGfchLDUmf6CffaUYCbu4FiId+9+dcTCDvxbABRy1C3OJ8QY7cxfJ+pEZW18fRJ0XCl/fiV/ecAOfB3HsqgTzAn555h0rkFgay0hAvMU/mAW/CFNSIxV397zm749ZNLA0L2dMy1AKuOqH+/B+/ImBfJMDjmdyJQ8WU/OFRuGLdqOd2oZrA1iuPIa+yUYyZkaZfz/emQwpIL1+Q4p1R/OplA4yc301AqruXXUcVDbEB+joHW3hy5FwK5t5OwTKatrSJBkydSF9zdXy98fYzGniRyRA65P0Ix/8J3BYB4edY2/w0Ip/mdYsYQljBY0A== Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.50.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Fri, 2023-12-15 at 03:24 +0200, Eduard Zingerman wrote: [...] > Here is an option that would fix the test in question, but I'm not > sure if it covers all cases: > 1. At the last instruction of each state (first instruction to be > backtracked) we know the set of IDs that should be tracked for > precision, as currently marked by mark_precise_scalar_ids(). > 2. In jump history we can record IDs for src and dst registers when new > entry is pushed. > 3. While backtracking 'if' statement, if one of the recorded IDs is in > the set identified at (1), add src/dst regs to precise registers set. Nah... this won't work for "second order" ids. --- suppose r2.id =3D=3D r3.id here if r3 > 10 goto exit; r1 +=3D r2 ... use r1 as precise ...