From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=212.227.15.4 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793046434; b=0f7Y99vbT9HjjZHqKetSxSQONyXS79ldauPrwtmrC4CdPqtYWPAUvpw/sVnmJ1KtDchw xIW9xluG7xPK9VhdLUzFADt1emRkcwVRw+8FbnzxNEccXhADExCinxHaehQhCu541Lqqs vXCB18J5Qr+1ymLNkp/aGdPVn/x9Na+n7rI1JavtRqG+mjX0SsH7zScxovMDU5nv4wLl2 OdWzel9dGdR75svyhiLyLnd2t8x5+WxqSx/Kv1bizl8R6pvCnx905kusaXjPPHss52R3S c/b3nYtc+GYThHu6wUmvoWPFBCcN262GralTQG1ov2EGEx65Stu1cBED9Aa4wU/nMiw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793046434; h=DMARC-Filter:DKIM-Signature:X-UI-Sender-Class:Received:Message-ID: Date:MIME-Version:User-Agent:To:Cc:References:Subject: Content-Language:From:In-Reply-To:Content-Type: Content-Transfer-Encoding:X-Provags-ID:X-Spam-Flag:UI-OutboundReport; bh=0rFainJhqdviEgXERCkuAXMBJIMk47qPeO7jf0mjJHI=; b=Z6duEwnE/4VsnEL1potRV0Kycok7jypxquHCttyn+NvdmcYB+Q1iEQHizkOZ3IGze+FV j0Duu0iTeOZ9TrlTb0DX8qaG/hKOm4w4Zq8IWNqiFf5eyWen7qnGntFSe0DraKrdpjZr5 2H8CzOYci9JvhWq0WV7kvuQBgHLhLSzZVku8dnsR6eFkcD/OOUxWXO+rqTntMNAgEb954 O1U2JFaKlncYX6q9m6egQzgXNxCH+SifllkfeBvSXm7ADJimN2Z7r+lpuMWecgceW8s2w 0PLn4R0axDuaqWg7aFF/Q/fb8SlPFajryNgbEtDWVLbyM8XzMBVnsG7H03fPMKSFDlw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=web.de; spf=pass smtp.mailfrom=web.de; dkim=pass header.d=web.de header.i=markus.elfring@web.de header.a=rsa-sha256 header.s=s29768273 header.b=dHiZ3yZq; arc=none smtp.remote-ip=212.227.15.4 Received: from mout.web.de (mout.web.de [212.227.15.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A650606A31A for ; Mon, 26 Oct 2026 20:27:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 2A650606A31A Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=web.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=web.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=web.de header.i=markus.elfring@web.de header.a=rsa-sha256 header.s=s29768273 header.b=dHiZ3yZq DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=web.de; s=s29768273; t=1793046431; x=1793651231; i=markus.elfring@web.de; bh=0rFainJhqdviEgXERCkuAXMBJIMk47qPeO7jf0mjJHI=; h=X-UI-Sender-Class:Message-ID:Date:MIME-Version:To:Cc:References: Subject:From:In-Reply-To:Content-Type:Content-Transfer-Encoding: cc:content-transfer-encoding:content-type:date:from:message-id: mime-version:reply-to:subject:to; b=dHiZ3yZqDAa19vj3jaF0D5IbhHS3fWz1nI+cKV09cRiC/2V/RbmvzsB8DQWuQrlM 5eZojsQ1kR/p/7X4tFh+Wdj1+og7ghN4Ti+7B5wh9JPyvSEtgKIPZieC0gmi0a+f/ njX3pU031x4VyMPrNhaftt0Nm+GfSjWAdjrTWgwtWSpQZr8f1KtkxrXTkiXNWAEW8 tT87iCWo0ubz5jtZn6ExhLgfggKMaMg1eOjCQUawLepVH1eyCxPyJEIjQ4Kh65u1O 88SWRSgDZ3BwgOqpMn3RVRvISBaZ+tGGrKyi7DUaUOK2RySLYIeTWFQMFLql92VbN Uwm88kh666B8/3ttzg== X-UI-Sender-Class: 814a7b36-bfc1-4dae-8640-3722d8ec6cd6 Received: from client.hidden.invalid by smtp.web.de (mrweb006 [213.165.67.108]) with ESMTPSA (Nemesis) id 1MeUbo-1wl00I3yRY-00pJfE; Mon, 26 Oct 2026 21:27:11 +0100 Message-ID: Date: Mon, 26 Oct 2026 21:27:09 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Bart Van Assche , linuxppc-dev@lists.ozlabs.org, Madhavan Srinivasan Cc: LKML , Christophe Leroy , Michael Ellerman , Nicholas Piggin , Ritesh Harjani , Shrikanth Hegde References: <56f0c45723ee53149a21ceb599010e957457afd8.1793044370.git.bvanassche@acm.org> Subject: Re: [PATCH] powerpc/iommu: Fix an RCU read lock leak in mm_iommu_is_devmem() Content-Language: en-GB, de-DE From: Markus Elfring In-Reply-To: <56f0c45723ee53149a21ceb599010e957457afd8.1793044370.git.bvanassche@acm.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:qTKgH57TOzyJ5nr5xKKTUtBr2l4rXHfZPZF2pcEZTRYDGjUdxlE BXKBRZAupAc5mNFpzrNkQk4aPUteBJORH/mhRrE1xIfiCAtTd/t05frACCZSAvljB6j5gAX zzYVZL75Ky5DJ5rH/xANUr2d0XackBiXZ6JjyibDi9pwI4JFSlZE4E04IRjGlWYqYIdCmXh DdnCCfrCF5/8vFgeBWIjw== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:rPocoWF5R/8=;SuDjSbQw5iSaPim4M/rBY0kW85S Hb0R1cQhFXXH8S8R6O28+O2TpWtNebYxLoVgd4OcbYciUcYArsyKbr3ubrOXraJGDYCLyMvUs u84p5bhsdwTFQ0w61e6XWzCw+wHZ7G7u2pJzHvMVpFyTDJbZvm/6Pn4x9GWcJwDu5yeEL4eL8 +gQ7oAvhB+nrKf8lErAu3Ich/+JDVl+RlS9zUETvWIvSaCbLrSlS+A36vtHKdigQqGCOgjq/V AD/7A8jUtWpx6A0Kz/AXpvB5ypECgT3aORBmhjmsv8YMyAVwXMoeCKx+15Nb5y7EjKSWSLhd/ v1qYrD7W91o3Gvsirirn2cF7PHBGIPaayhbLjYrXYgW7Dl2k9rP8brkrmNy1ECMC5QB7CEP0k VMIXtb4GWG8r5Y7G9V5BovjVopwZ7cnM6iErRp/p+JDnHRe5zue17DejlLcgvTJpd2+seRX6j 99ye789pyXKva6oqOLwPYJfoHcIVWV8tUHgAA7KZN0/42VMKMtS/Iu2JstPj5Tx8uTQ5j+jPe BCVwOAMUBvh+hdHVKrc5HN1CJaQ/fpAm6+1ur1t7/sVZ6iBLB3on+P8KDlA9r6YOWrQD6gS51 Q+tQ57Ec50id7DoDVMHp5yaoD4oxWVktk72bx6Oo7yKKLtXbQFzyp2c36IiWjiWke7fJYOHN+ jzOttxiKAzB20UEXTBfF99IvTJ5aUAQyYiqDM5yMfqUVDjCkbHjHpF4r0VVPgxu/Wa+N/w8Cs MVLfoSsD6Tv5n7LLe7HlW8wKx/bHdU3NomxyjiIDYafQSeAZe80cENM3a672FVsdi418dtFBb oJn0i4G1KxmJuFpGleE3Fy7Umy6hnbAGOHUZxxmPu4A+Jc9tDzGGu8c6AoPaUYxWxVKHx+JYc F7pA0PvUepfkME3Cp7Xv0UwefW1kTGb/JvHlg948jDk0q6DnH9k2FZ81YYMboi0iMIdBm8z94 utPPlHS/wdF59TFA3yOA2acOR46PRcEnPg0709MoxV/meUaVZZdeZeEo1bvENHsVAGuI/0ns3 lWkHMdCJZVmWjsIfTlqsbC5Oq8S21xaR4xNaw6ygft3eznGaTvkABqRhv+TEiu+2kb/Q4bMhC bP52VlbLyu49EbhuQxbPu/FFgMipjF64fz5p7JFXocfDYeg+4ox2lXQ1iuBEzIEApCpPvBhqS uXxrZ5lGB6QiyQTOSF198PalFM1GxiGIsLhje1oyGp++j3tl934qfteskAorJhZ02xWytsFiv KV8eDIUKiGl7xr7QV+eoU6IGA6fu3PwPOdLdi2jEME0siDpZw707eZ/4rYPNgTxXSjWltEtwV 8oO1AOIbwgmx3eleGmPdRTWNOWegfErYyODS8jgUS3hkSA91eB+f27frYWKKJ5EJ1/Zaf8766 jc77f8RNBwVHlRzqvcoxv4cW00MVEb7Gf9W2NFJR4nPEEL5lgvnhRgkKEf9gvHmSY+CUxkYxb bLqNe8OSXxdbSH9C++pVgggV0/mQ/cpBN7YNLtYPlQXdSgIgghgXTbt5XBphS0WJ9t8OkcGvw bF8WhmD2p9L8ttmOt2D0NAA/KXSU3MwbqRC/uGNvrrkapTp51b0RIGARK0wuCx8fydiHkY1Ai BuWys8h8iAw9GPc3wVg17lLrXLvL5oloaaz68/utPYYClLLiPcgwxRGBc+J3rnhZbjGFvftmr ExeHPQV/I6SZWS0yeUkDsg8BK2LQlf0Ups0ZI3wXX2rp6t+/k9XhpW3SMsdYmP3LeL0uTZgDM AgvhDTXbjK8Ih0f6cLAxNmo38DcqwNp5lrAr6z46xCbi2zQ/e4uLKtAfp7b78Fl1sjcxHqp5m t5WqDwchMizDpqsX8BU1kJVVi8mGxsltNElYAT3Ck8AEi7RAQ+AKbXVlvdFsmQ2e/gx5Bk9ZH /xfkca67ZC0IUqHmLHMPT6raHHdy2XUMdUi8ObuPRLaWaVW/7Q7onUqXSiBhykJ6oO3TmOUNQ TW7OZ1hbQn6tuvBPDTlN11EpQ/9EJPkWsFLBCN5wgD5uTyXbGyxjfWQ2AnZ3THPfYl/0yhHx7 JMUMj6qQtNI8YyEuasF9nnqE1E+SK4XgGzCneVsoZWnO26qsDS8wAXOGCMMrYUnAc5b7KtWWE v5Llx8+MJaiU4FBn3Z88JTy4WtuYErwsgAbxwlJ6SQP05ozGasGdvoLsv9QwB42vj2ngz4THn 1KXwxuNgTuzI3ncRT7mwUI/+54i/r+e1+b8A3vp0k036LHoDSNPuh7oOFU8kzqYbiTpDookZu utAu+EJIeEaJwBfEa6Z6ujd0LEl6s/+jB5hw+IgerR//KLyTiEkINvYqDnF+qaY7uEzevUTIH e/aNYfLH8iAIuxLC4/8vUbOSHO5cii/bSf/3lk8QyrQa1nh/ScY7KN7PMK1XnUWfg4uApktUD FnerYikYwr0mnRD5bfbYBVJ2h21NYJoSd/s5QpUqm5ccbv1s/+FP8ZQ+fqQHR3b8u6ytpEqH9 nTrzTAMS2Z9c2TMNqjwqtr2I26btHt2Bey/hNI1X1U4xCGYE2RM7IBd1lPYCiNnfk0hJgkD40 HEHpnQ5uFY5p7yFBzqtSJLvjfTpWGs9c3FaD/IHuGb3zZ3rV29lJV6AukyrrfKSNw3pr9x7Pi T9xDvMN0zdtDbKTg75i0F5Yk3ldDdTnmoydeqMISIkR/XF4DHC9gXBeTlgNKdpdS07Kw80JM/ o4AZ2VtW0xgYvJOfgezUHFVWEDpXwVk/8XKTPX3x/EXfTfHaAQv0Y+cFA+DC06z2YCIlP+8Gm i+2jP4hwTt5zWKRPN7wnFn9rW/WOeI2ozs0UV3Mv0GwvMOZ1R5xGLrFAqCnE5/kF92/riLda+ /FTzaMj5rYh31D+Ha98CiScoVkAN2y7qinf7d/hIv5UUOV+tsUB6oqoTnVwuIgWrHogsOA/A2 Oc2x2qzWf4QtS8SoF5KVQsCc+C0V+qmUrh+ZCVeMqWQ/2yipefcAPycAM0hqNn5Xfococ2xiG RtQWlFYOsJLea21g16dbMNcOl1vU006KOUKOHavF6an0tWuET1hBsrzHFk8rxSGp7/VxAqAYl LkBN4VVu8qJFe9QELvTSyDF7xegx9bFfxHU2cqEbAq71X1RUQRlUPOvo93kfm6cI2VlZZ4FjX JNChFazfHo5qRvZYecds0yvwih4YYI8tVLxGUVltxi2i6SpGckHDogCGwkuNL93FfUZtbD0mv 6lsIx7vk9U7lHueRL26F2zu7KZdaBHQpGgqJDNC8o/SLZ2dtEK6RXLE6vIQ7MeSpIGWCnc4Jc lcZFgr64I88gzxSyqTfvvPX61w4PKRx+zr2wcpSJeG0DxO2x5AZWwqodg4ZuCPQNIK7D79NAr h6eNyrIQGj0DUyUVQzjd643gE3/YS3XLjFqjxJBAHzpJLk1GHdaOHIYBjg4w2VngPKvNVwwsb qt3b2ZnHyy/IvtkF+VXodKqZvSXAAAXB+TH/OH6hzIAa5ZFxZGkHTv3hhztvXxpypqNDXpcGE RyRokgVFQGkpdwoQqq7t1lZIP1gP/gR5mXfjzVBL151awAnV6zEcchEJYPi4OREWeoY3g+Fyr LtEz1nf8C9gcL9exlZlscXW8MQD9sJb0VURGUzMGpC9fn1hHBTw3hbspkrP7cj6x086SR8LSv sXfEriSzmAMDsghKdbfPzACkTgT5on/1P0T3KlLUwQB+QOrSD6n3Nvyk8ZcMOuuT+e7Iacj4j I7JwPAoEVg2x4vQaF1GfnFgcITAwGqHtlMZU9II3vT3Snm7DQ5xPPRFz6xKca+9A1gZnbpyxZ CN2CibcSOo+aQ3kUbg5Ca/jFvSABp0yB3azViD6HHEAzvFgWE1DgNZehxGqubDOuIoRRVlM90 WM2pqtXO5e9tuscRdhnLhJETNyWbLIDkuW6TwrGvOPmLY5Cc4anOrMBetfVkkYE+vKcX3KRxs plKZxo4+h2/AvBW/P6T5acoGl/Y3j9X4NEK793UsG6tksajwDyMCsK9NbbZY98eRmGZKY3aVI kMfR7wqRwIR4p/vt+YPMbTEZuRLeEpCXmOZfnnUttVRuxqUXt9SZc+RKa204LDQnXyhE0/DFC cy2MxSBLqckI7xVoRAUUEgyvF3Im2y00QLuwbOH++5/TH9wcdIy367POemLJK4DpRO5L0pMU8 TxeuAylrrVaepfM/RutX0CbUNFBW3BJrvBj1BvtVOUHJXBKOO8J4pTrIQqMxFDSZnGvFsXj6e tb/mGViV7pg1czug67sJrIhOS31Wdm7l0Ae7PWfRdGNjbrLeZBSN1HF/VCT9ml+qrUxCvWzM3 Ax21My/LqJuOghUljP61ARc9BZ2+n+oc+W1yE0GLyWlRlcrmCnB/6x9l9ULSXLtJiKRWle+wJ qnnQO4O3OldrrThBzoi4TiikckH3FycRv1Ueo9CaY4p9nLESqWOTM0z72xn8T06g1L+2iWH0R Y9vFqsolEm2A0CSjNGnnlO9B46RAKCrXL3QA0iRwQ7xsQr79YIfoAYjTgohol1gkhEZYmoXJN DwZISEAo4jCBlPxvUMKj8VD/uPE+NpTWzKMO5okV86dyHvI0NtO3DBRZ4UM/9ZivpDC4ioZtN 2XZi5ciNrcC9gL/6ivFhNu1D232YwPlHSbexN5Frqg/wJ38wIeDw86mi9v5P77AssTswsXVDv X7IxAqdfqWn7vGqylpQGDBcq7FN/R1V2bseiAaWuBPBrdm/U8kbdman4j9Dq8gMU4uBq7DHqq cT6qJTf/D2Se/+nxbdhrJR2G6hpVuPM+cO7bN5ID0yQgVbGHM7m33w8uxEBjxYhIQx/OG8E0j GC5OohbtgrJkorx+vIMi0O2g5cJcOqPGoUasZw6jWqs3eZfraC5Wx37ihK5bXiCbVzoSsevQl n0szn1YCVeMzLa+2n/8FFSympHq35BKbPsfBH3RiZ09KO7JauLGEA2T/NNfgoCC+QGYjAFpzD 2W3n+BkEiwfDeh8tcJsVEPvQjc5LrFydpRCOxe6mgnp37PhxNRziakMZkE+wy4S+hqjLkb1AR 3nBIOSh2zekVfv9GGx47LA7LjTftjHpTD2uC+9LYDvRqCzIK2ExjGwRyH4kLxVVAXaTYjv0Vi 0bb+Bzrtq3dnw8TEMND7npX0sXq7fbT5D6W6AHxz1bDInlaFs/ZFIAgMsFg/GdAiOIqwxYohQ JmHhXxJ4t0PuA/cdptlkYlgV+GkGPijh9SMsdEsAyFQnIWqTlCyPG5H2aoJUWlRJkRZEsbssY tl0zFk+DXc61TZPEz3ozLjtFS938NGcju+h3YfexR58Ly5+yb+mtXfrla3SnnlkfQzNWvx1+m dI0XAiGeGwmK0gP+1MTFkUnWsNtNO6RvqzT2id51Pjhv9V5woguBlSeS4gHTuq7emIHQOAsPm 25902TcmZJgmlrHoRQr8nbKsL0i5MkhoYTWWEGFADC3OM+zjK3lBDTs/ZLs19a9akRhRr8LGl oH3qc1/v0mcwYi2lZT+CVUt7K87RWHac7ZbL8OeuAPwzQGRy5R/LPKAGk6aKP3OVzJ2pMphs+ lcjarImjCPw9LxgoExbm4H5lTZOEOmvvWZdeD8t4G6arT3kagfvkPkBDsVXfQdSBziXohjOvs xJ+0HzJiCviuTWqq1sU6jRtZ6isTkgeIcq+genqj/ElNmLZOMrpg6gk6f0HdGRmmC8QAksntO 5T1C7OhYybmzwLlLyqjmBI4A9I/j57jH99Lz7K+fdVqrnWxijglQ2kEQvmMHf+Hw2GIhqV+H4 j/gR78hWQWwE4oSjtiJJLeO2fkj8c+HkjFJ/GXTUXPWdCYWFCwrWyUPl99rNSk9SMdK/qsTLk w22xxYXqKCq+koEeitCwE+NINQvEKhfLrvGQFAyluNkpuOw7YTWXGoDHyZuNcEVh4ZpgIT4qM jjE7HJqaTsn2GqUYNrChVpQziaL6qZs/VPhgNMCGf9eAPefSb6IQlL0ndMASMGyay23zJesB7 UiECq9iGiWCZcVF2ly6nuQBSzTfeB+dYnJDveDo/eBH+mBMRDzPTH++CjScFiK3Zkbqkdpfsd ZLW5a6+KT8Kh0YB0LW0m40hLd5IZnRR+oEJaxomEyt5rhroIf+Z67ghJLxiz2N2RWboaTINlr RpQ0k+O9+YIgdaR383n0x+usuFwLNaFNOpXciv3Z75otFDYkd7UPNCmxc0T0YvqHhXELL8jJe RStP438wOzUgl5gYRTh33k7ciTBdNCxHmNzrE9zgrtGkAnYKpY5upibrjPBRziOgxk+CJ8zgT 5KIw7fzElmWDZa+B1ozCTfwMWzd6lhqdtd8oQ1MXgcNzT3HikwRGplsrgocfa91ilCVSoRAGM qMeUeLawtCcgltudg8vxtu+geyCag45nXjhHHOnr8B4wyRFIzK6u86o6mYs6jLek5WpUJblEo h8DGlvdP1I9/kdjHi1+hyrdsaPrUpC27yvfBMci1VfVZ0HObCXy8yCQNnyE6xsAWCf0GNlV7J 7bL00L0ZRSb2GHsySzN84t0ios2EYr8WFCNK0O5J+yxoXOQRgL9DPwEd2UtAXRkHw0l/m6M/o SOYSTqgMrkR8PJN65ptP+bNEdJ61fTnCjvGf4mANuaRhz7D7qd8Bk+2kfotPeCzqbH18OzJNz XBrqTMk1GMwxENjbseIFX2YBtRI+TAgaTP707Zxv0o3/YZE89RL+Gv+Z7L5wJm9yJ5PAibiCS jB892LG8aliC/xBJom8WafVI0ZYJBMoY2gHrfKt/CDCw5PK6b8rKOJyzRmOK6TqgnQvxwIez6 xWOQcLjbMF+9J/OiEQp3Iib9Jq6FchFFqX8HM14XIUdW9kOByXhAcvP2OKE/d8LJvPs2I/0XB rrlFTZUUGUxwzujvOWgeDrlT3PGopNj+uj8FwKIB2ivWfAtlv6nDv9tqimcmhm+ff+rEW6ReT mS/GT96IgRO7dREQJx+oojzdEE9vutqboUoDjDu0Bl4XiyWgZgQ74X0Yq9Imp6X9FU9/zCIPN gVGIBNjG2dgPIko7kreA2ZVbj9kDuoZPEM7Wl9NXXk/6aY/EnqNQhAWZX+4C+xMqyk8FxFm3S pDSr4bAcPSRP7D2rCEdAa+NHyFoZtuK61snMw61fMueEEJKO9eBBLi7ijHbgOJ6XbLPMEZWEs g19pMp7GQZb7PllKyVVRW6uPHzDtb91whveW/DA121QbgbytJFdGL+zvrIoYPdFTt+qSvEe7x 4OPSI9J0rpZa9cQhIyISMMpT8HsAs35rmv4Qpu4GWkawZsgKdqcbwRlwJHJ6UEXCL+qsCUgli dEdaTzWqj46vuWYl+MEULKzWnnBNXvYV8/13DDx9/fpizRUYjI8fkxrmXxGQgyNggmTIGv5sY dYSB1pls5rxkoJTu3Rdl7JgGZh2/Rp8rKug97HFQ3jRZxQ196IKm8nTfBUrlQHgnvWX64iaKx IIa6+Dlz7ZQuT0F2tzpgyVDJ2CZ1VtlqWU/Q82c5RA9/unMtonmfTt3xKZHYmkhyJjOGjvYgz rzO5VwrQi3nHl/jd7mRCPNq8I/ug== =E2=80=A6 > +++ b/arch/powerpc/mm/book3s64/iommu_api.c > @@ -371,6 +371,7 @@ bool mm_iommu_is_devmem(struct mm_struct *mm, unsign= ed long hpa, > * and the caller needs to distinguish this situation. > */ > *size =3D min(1UL << pageshift, end - hpa); > + rcu_read_unlock(); > return true; > } > } Under which circumstances would you become interested to apply a statement like =E2=80=9Cguard(rcu)();=E2=80=9D? https://elixir.bootlin.com/linux/v7.3/source/include/linux/rcupdate.h#L121= 6 Regards, Markus