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 CEE03154433 for ; Wed, 4 Dec 2024 20:12:10 +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=1733343132; cv=none; b=CVNVx4yo9RB6870LJh1oZA/k7Rvnp+W0pDnmC6mIrw8BgcLusag/baKe+IpzHDs7PVWSAII+YQacscmIfjthWkLyWyJilx3ZF9Mf5iOIHSC42bn0mqv5AvjwYud6ZSGEv+oVwBX2sObesiEWWnRMYNUssGGuXPDeNAz0yLiADWk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733343132; c=relaxed/simple; bh=+tYABKE+9VZ7RMyRCTc+tYyfN2yVNZw/8jxpGDZTedc=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=PekNRqB2RVmvBKOzNYaPDpW2d76zV41S9PbOAisrktfXYDM3sQp9w9rJfEyNclbImh0YA1x4h6rAWDz9x2K82xiQQ817FXWEnTOT3A2+T+OQ3dx9ZkE3XDXbQBVhyfFqgF0HiA5eC2hkA0Nwc7W4hF4ZSSW2QbZwwyioxsDJtnE= 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=mIIldsYj; arc=none smtp.client-ip=209.85.214.176 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="mIIldsYj" Received: by mail-pl1-f176.google.com with SMTP id d9443c01a7336-215909152c5so1418865ad.3 for ; Wed, 04 Dec 2024 12:12:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1733343130; x=1733947930; 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=7GBC6xfTNsIXbNlV9Qs00AxRvgqJbQsfnGWeYO27AeE=; b=mIIldsYjpL6sgoy3x9JbF6WtzoHZjelRKlsdT7iJbqY084n6irmrq3XVR1gb6lPAHK PW6Ogres96D0cvOzVQ05hCYptxvm0iR6vUu+HvfnMzjt/3cAC9rz7WJKxXAaCRypTI7r H3ojAUCCQqejKgfYGgemKhxO0nQHGM+Lzy7LoWyul5mp/19u1ASwCcjEzaGpDexCDsHH DCuUCQW3Nz+sutvz/0pqg3YQdU66A7FPsCSFkGP7DnVEkcM1GfB+skbBKUGtsba2tVms SZWALeEVIiAODzS0EP9eJdC0HxAmmE5hd7if0XwZ16qjyYT7sW02Ngszl2bHADOr7W+o EXEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1733343130; x=1733947930; 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=7GBC6xfTNsIXbNlV9Qs00AxRvgqJbQsfnGWeYO27AeE=; b=fWLFY7YEfbmswZU8pmEdkqSsf0B0y2OarvPKGJ7fCmneYF2oEns7qSF+bHf7PWoWaz aD1VOj8Gb8RYHOxCWKXklFdZf1SGFtTGP2NjCdPmzDQbr4TuoYBwYUmgKRBlNMGlDPTf IBgGEle3fplloKs00E74WQ2dMPTtrUFlc2sePtJk5mQ8O3IIwAcl7cNU1jTjvjObWLQM Hz0EY+EbXuebWkX7PpeBwhduJ8hNgXgCTbr8Cd852ZJGqceA7YkDnkI2IbbAZIlwSanv 1cWy1kGqLmwOOIGHkww4JNSc4oqRCg3sPFmf70TtiMy/FiStuyEVeFA5gRnFwZXez4lO O4Hg== X-Forwarded-Encrypted: i=1; AJvYcCUSIi2ddgDWbq6FyA76ddFGJgGuGFpTHPE0IOHTxXfQ2FVIsAmGSM8VUzVC+b7MaljgLIo=@vger.kernel.org X-Gm-Message-State: AOJu0Yzu8LEp1cPDEHGMxaF7JtR+yYgbVAhLuKtqoqdI5LtvFL4rx7is H/aVnSdilGrMwrViQ5SEg7jsn75rZttqp60TfmR0jCqL1B/eqx1N X-Gm-Gg: ASbGncuIypTV+aEhai6T+eqzB+1pBKQNwuqWzyARMtxH+OKAmLq4ymeXMHOoFpuGWXp llrgJFS29pf3Gjnon0I2xnvxjF7xDxWbmmRQ8xARgRdFR+mdG/BgtRrK9dVW9ol5toH3TC7ntV7 b8yNeQtt7lyVCSASwi3i+bBmv32Al0Y5cHZRi4Hf6grQy3+KAPjhNsnXqb3/YBn4exsc6BSD5PW IbYZzMRBYRSYspUgoPClhyCO4/nNi+K8hoQ7u0J3bQWVTbN0s2kCL7UIaaVLXKvWT4OLuF88Mic X-Google-Smtp-Source: AGHT+IFxYpodVK+rq3YAN1p1uS5dI4YBFBncPPJ6GOs2Uh9HBCIY7W2L+1wKhYDVuQ0XkikzC2nPxQ== X-Received: by 2002:a17:902:e80f:b0:215:86cf:f10b with SMTP id d9443c01a7336-215bd1b453cmr113058345ad.11.1733343130152; Wed, 04 Dec 2024 12:12:10 -0800 (PST) Received: from ?IPv6:2620:10d:c096:14a:ab16:b297:5216:f3f1? ([2620:10d:c090:600::1:468e]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-21589aa5478sm61730395ad.59.2024.12.04.12.12.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Dec 2024 12:12:09 -0800 (PST) Message-ID: Subject: Re: [PATCH bpf v1 2/2] selftests/bpf: Add raw_tp tests for PTR_MAYBE_NULL marking From: Eduard Zingerman To: Kumar Kartikeya Dwivedi , bpf@vger.kernel.org Cc: kkd@meta.com, Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Manu Bretelle , kernel-team@fb.com Date: Wed, 04 Dec 2024 12:12:07 -0800 In-Reply-To: <20241204024154.21386-3-memxor@gmail.com> References: <20241204024154.21386-1-memxor@gmail.com> <20241204024154.21386-3-memxor@gmail.com> 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 Tue, 2024-12-03 at 18:41 -0800, Kumar Kartikeya Dwivedi wrote: [...] > +/* r2 with offset is checked, which marks r1 with off=3D0 as non-NULL */ > +SEC("tp_btf/bpf_testmod_test_raw_tp_null") > +__failure > +__msg("3: (07) r2 +=3D 8 ; R2_w=3Dtrusted_ptr_or_n= ull_sk_buff(id=3D1,off=3D8)") > +__msg("4: (15) if r2 =3D=3D 0x0 goto pc+2 ; R2_w=3Dtrusted_ptr_or= _null_sk_buff(id=3D2,off=3D8)") > +__msg("5: (bf) r1 =3D r1 ; R1_w=3Dtrusted_ptr_sk_b= uff()") This looks like a bug. 'r1 !=3D 0' does not follow from 'r2 =3D=3D r1 + 8 and r2 !=3D 0'. > +int BPF_PROG(test_raw_tp_null_copy_check_with_off, struct sk_buff *skb) > +{ > + asm volatile ( > + "r1 =3D *(u64 *)(r1 +0); \ > + r2 =3D r1; \ > + r3 =3D 0; \ > + r2 +=3D 8; \ > + if r2 =3D=3D 0 goto jmp2; \ > + r1 =3D r1; \ > + *(u64 *)(r3 +0) =3D r3; \ > + jmp2: " > + :: > + : __clobber_all > + ); > + return 0; > +} [...]