From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f172.google.com (mail-pf1-f172.google.com [209.85.210.172]) (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 435A62BAF4 for ; Sat, 22 Nov 2025 01:13:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763774001; cv=none; b=V5fFwF+DMKnsAL8vNvCy5fLK8v75nYOIvcFZulfuEi4MDPHfgciOF8Gs3MqQEhAp9ROA5RxnzEkvF7q0asMC1N4fVALRs4/6LTt4Ok5ieqVaWo2+BOG1ULYIuc9dWMqGsy3WyXDcJgXheHePTDi9sSf6wgviFB5+Snzm7Q6C1QQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763774001; c=relaxed/simple; bh=saP4U5WhwlXVToCCAufwLLzNHnfjLxtTvbXL7C7/9I4=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=LGRcgB56JILgDMegvZmgrpnyAF7ZtQXJ/BrvyeNdarWv/cpY2Nj/6U6nDYsC/raHXsS7o6Ehw3oBw82sWy/u9uGnThUSISYRRKN5LkuFB0unNSh6sAqJxNhZyNT8Ohzy3s1wOElQdNIlTo7ZukmkiiwyH+UAlyObk+7QRF19o6M= 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=MZL4VFDU; arc=none smtp.client-ip=209.85.210.172 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="MZL4VFDU" Received: by mail-pf1-f172.google.com with SMTP id d2e1a72fcca58-7acd9a03ba9so2884813b3a.1 for ; Fri, 21 Nov 2025 17:13:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1763773997; x=1764378797; 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=saP4U5WhwlXVToCCAufwLLzNHnfjLxtTvbXL7C7/9I4=; b=MZL4VFDUVF2XUuut7Eycu2BwuilcgJ6aSQHDRyAexb3TvoDS43XeGcaLR5Vw7SRHJr UqhvjMZz4XFbOu4IEIj3Fop+bUJlQwgN81/JhfX93TT8eMINaKgGeblu+oTecewRaXp8 ST5DjwED2OFMi6rCqSqIgTlrNYnY+s/vtyfU8y5ZsskQoYQWjNyrFGk1CCHRs81ZT2Ox 9nVwR0SCNHiCIoSdcyDYVTqyDBcyHcNPvbAsrTnudX4ERxEIBc+Siuzv1G9h4jTEpKqu Mw2fY1qobKIzgfLEvlIgo0DHVMlB8uKPmvYPeXEO3dHz9RjB4Ld1rizJigBDLU5nu1xf EulA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763773997; x=1764378797; h=mime-version:user-agent:content-transfer-encoding:references :in-reply-to:date:cc:to:from:subject:message-id:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=saP4U5WhwlXVToCCAufwLLzNHnfjLxtTvbXL7C7/9I4=; b=RBCdsQEWoFKhLuxXcgC0H4MxLLAXa6gP/HxA/WqMB8zaNe7lIRPLxgznMghLhPFKzI 18jIkcLZfPmo0xjYFHt/ynaJlQUfze0fSPJcI0vrYLLoUfcSlRf4zSx1oAeOfpiLFJcn 6ruhlu6nWdRJoexnDhRJCvfVF5EalY8Nciorvtc8UVARKsnhpYD3A76m04Cox1SDksmo mRIb7DLQtFa3F+AjbQnj67IWN7zR/fFTK0Dnp8zY/AO4VgqCSDmLE46yC46+CnGf+z6K kukpmadMglwldKKV5pX2/nlfO3zzl4X1xVcXQxsVtA53kHZRbR1EZM8UdiZNigyxwfQb Baug== X-Forwarded-Encrypted: i=1; AJvYcCXufnoax02bA5MNh9vKdh5T+uhWpNWRjvbi9DsqS23KiSiJJ6L2J0T99aG8rhYnDlY7tx4=@vger.kernel.org X-Gm-Message-State: AOJu0Yxvf0GJYYUHeeMsNmZ1A7JbZTQedq/KVzXQC6mcHmQLn2L1pzW3 P+Ew+OYPF69XKNe/QnwQ5qI20oSecF0DOps4SIbq0W6UcSNOgrjTvSDc X-Gm-Gg: ASbGncs4H4PyP6I5VFMsSNVFh9RSJfjXyyoEpNKAD9Dp4DZtITaEQkRZX2br5Gn5Zfg 8lkRYXhi8ypxSRvao6mTJ1F15sdo7JkgzUCEyyrVEsYzNq0qyGuOvL5vN3PpzGhQ5/k5iqAhN1W KVXgwchQMkakvhPPoKrq5TJk+2StbhD6hmj9J8+4/msZKANcNXyQyip+X7PO+xHqWsBzDodZM36 Amoeq0UzAP9CxrRS49kT+ODtnF1+16QwINmef7jE3ER+hgSOod4YEk2SyANBV4DEtN+XYeZF3k8 8tOLYMNXfplEPFKoTMpWHmL8655oFoRqMNd3yynFAkxXV/ox8UZxu6i+SjpPo+DfpGOR4wXvBql NdcSJ6reRBrMv9EE5OgmlmHxxXNVUl5Ham8jDSErBW4mgAmNfSkBnnlh9qxQM9Zn7X1eSq/Rks7 i/FxSlDU0= X-Google-Smtp-Source: AGHT+IGIIcLGKXwyxuZlN6zxJg+WkVgPCE2c4e1rlk/IN7KLg5Hz52zlgmkpzsDz9+2o01MH/tdE/g== X-Received: by 2002:a05:6a00:3983:b0:7ac:78d6:5f00 with SMTP id d2e1a72fcca58-7c58effc48emr4683334b3a.31.1763773997302; Fri, 21 Nov 2025 17:13:17 -0800 (PST) Received: from [192.168.0.56] ([38.34.87.7]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7c3ed47b388sm7349609b3a.27.2025.11.21.17.13.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 21 Nov 2025 17:13:16 -0800 (PST) Message-ID: <9cb294bb7d786f8ac3b55a2593fb15e76b5d9696.camel@gmail.com> Subject: Re: [PATCH bpf-next v2 1/2] bpf: support nested rcu critical sections From: Eduard Zingerman To: Puranjay Mohan , bpf@vger.kernel.org Cc: kkd@meta.com, Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Puranjay Mohan , kernel-team@fb.com Date: Fri, 21 Nov 2025 17:13:14 -0800 In-Reply-To: <20251117200411.25563-2-puranjay@kernel.org> References: <20251117200411.25563-1-puranjay@kernel.org> <20251117200411.25563-2-puranjay@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.58.1 (3.58.1-1.fc43) Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Mon, 2025-11-17 at 20:04 +0000, Puranjay Mohan wrote: > Currently, nested rcu critical sections are rejected by the verifier and > rcu_lock state is managed by a boolean variable. Add support for nested > rcu critical sections by make active_rcu_locks a counter similar to > active_preempt_locks. bpf_rcu_read_lock() increments this counter and > bpf_rcu_read_unlock() decrements it, MEM_RCU -> PTR_UNTRUSTED transition > happens when active_rcu_locks drops to 0. >=20 > Signed-off-by: Puranjay Mohan > --- Acked-by: Eduard Zingerman [...]