From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f49.google.com (mail-oa1-f49.google.com [209.85.160.49]) (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 EB7DA2DEA70 for ; Fri, 5 Dec 2025 16:52:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.49 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764953580; cv=none; b=AMnQvYyRSQY+oER5ty5uD+gbbEip585ucg/PXKCvQpovlVo72r3/ZdYBo7TF8JaHt9nTvglGWMoWOW5C516/UyTkYCmrNi7JsocLLkIPWoAiSWiS8GAzGEPUs9nWAVx5dbMBTF2vJNlkQYwDR51ue48jIuVNV89WIyiVm2WTZnQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764953580; c=relaxed/simple; bh=+g6uqAnbC89NpMwdDhzAjO8+Gri4EzCzfdoe7GIPweg=; h=From:To:Cc:In-Reply-To:References:Subject:Message-Id:Date: MIME-Version:Content-Type; b=rhu0WCFPS6EnXsP7aNZi+gO8Gzb7OPAjJo/SLoAGLwH7JEiGzDFNeHdC2Xa77EqwyKYirVK5kgDrEKE7Tss+EKn/P5QgqBGGuHgItxQq/8+S/B4WLqZvN3GEPI11cEEk6gmb70XR0H2CJFxvXIDIprs3MIbChqsL5hIx4Isg5To= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=oM0ODan0; arc=none smtp.client-ip=209.85.160.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="oM0ODan0" Received: by mail-oa1-f49.google.com with SMTP id 586e51a60fabf-3ec31d2b7f8so911133fac.3 for ; Fri, 05 Dec 2025 08:52:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1764953572; x=1765558372; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:date:message-id:subject :references:in-reply-to:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=w8SKMX4ybu6h8zNWUZiAOTt8fMQRkTvyjaDYjeKxvBA=; b=oM0ODan0DI8NIAWlHClSnAM2R2TJn+/0hXp+/mwVtOoeoj95s9j+XxOOt2UjxEXuaI HvpL4ywfkZ9dKDDArA17vLMyXsI//D7+hnAavrShvOgmvsGUsAj9UMEFdoVAvFhvfBHZ 9Hhvn5Qh3hQGGNj6XlelJXOyGwbcHWXGOlYu3BhCRGfLbX2SGg41ifT0nO2TweDo9sRi xgB2YMufS1XXYgbh+rFAAQpeGHFj8ptiY5POudwPMgG/qc+UO8y33bsEIMjiWq4DyKtX CCmL1DRQYkS/McUWqEoM872HQIeMTMurOy7WGRqBbCG287EVYp2pUfpAcbX0bME7uv5L cCnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764953572; x=1765558372; h=content-transfer-encoding:mime-version:date:message-id:subject :references:in-reply-to:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=w8SKMX4ybu6h8zNWUZiAOTt8fMQRkTvyjaDYjeKxvBA=; b=P/LdXiQfkVSlWnn3ZTy2z87forEKZmMb6xQkQLz4Up6LmX6DMMSFATdFyvBib8tyEQ FE4zwpOMfVzOfY6tSDO1STY30cfud2aDzncBRs2sHrrY/r105m1KOO0+iU/UUJRmnZfO JEf1bmm1awRr8mBT92Vtn9AWE/6pQMOeYp1+BcyoWHbs4mNs9RZTFHHCnATnVXU5WJd6 IOgWsNfIhNSkNukkHhS6RGh89myNXag00jBhhetur5zzRzZbnxgxlEoytffAI2MPzUX2 Dqvulaa2YVrcN9ooKrQTkUM0dgJDzSUgQPZ3XO2s45O3G4SwSQJVbDnoFHvoStEZ75Cv kUnw== X-Forwarded-Encrypted: i=1; AJvYcCVerFbDVGTUgvNXamFLvJCFilI0SNOtTsJRUcEL2jG3WWWarPwvrO1UXLvOlmhuZ86xb6REV7ghrg==@vger.kernel.org X-Gm-Message-State: AOJu0YxlgP2DguiTOBU72k00B5yROpH2bdF+0KEcFzfIsgXndQQ1cteF 8ueWgJS39gCG7PLbTIsoJD/tty2H7XhwiRooNdFt28vCHJkKYexaBhC0pnHw/sUbk+k= X-Gm-Gg: ASbGncs9wmTjdU0HXg1mvHb+xkiRY0lEsKemRiaINF5XjvBNAoMUZO9LBdlecm3AtF9 +NrkvV6/hoxS9Byr5aWO+symaMrOP1aDFtfqS3oztaJWIfLHUg2afpqjuHqEQi8da0GXTKh+1b7 zzGvi7r6ozigjNEDqAul601MCj/bET1oQlw90wS6/7/JBxEvk0y1G1DCWWYCqgGlKWMtvQaW83j /NKbYBfe2fJePmb7YQYpIVD7GPAfU0jF97ZeknbECVGZct3VThLPlGVrNhaTBDtVzBDDqaLru/A ZFyDovJGr6OW53OtOm6OqG44IOkJL3LiMVO7GAiQui3CtwWs1M8yZ4UhwHq937XfMHgb7RkUIK9 2NXRfwfFvB25x7Y+/tJQa/IyrCLAXIu8VPENI8Q3TpGMq3IcNboyqPi9d/+zAPb5f83r+QHUBuy vVtQ== X-Google-Smtp-Source: AGHT+IEevaXi1fBwIlO1FuNasBCIdcVM8uEAdbLWI97tIfwz0yxjFCAJXCYW9nxOjHXEQj4a/NiXeg== X-Received: by 2002:a05:6808:15a6:b0:450:125d:d9e with SMTP id 5614622812f47-4536e435c75mr5974098b6e.21.1764953572537; Fri, 05 Dec 2025 08:52:52 -0800 (PST) Received: from [127.0.0.1] ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id 006d021491bc7-6597ef0ca05sm2398649eaf.11.2025.12.05.08.52.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 Dec 2025 08:52:51 -0800 (PST) From: Jens Axboe To: Joanne Koong Cc: csander@purestorage.com, io-uring@vger.kernel.org In-Reply-To: <20251204235450.1219662-1-joannelkoong@gmail.com> References: <20251204235450.1219662-1-joannelkoong@gmail.com> Subject: Re: [PATCH v1] io_uring/kbuf: use WRITE_ONCE() for userspace-shared buffer ring fields Message-Id: <176495357153.1162213.11911701547224537851.b4-ty@kernel.dk> Date: Fri, 05 Dec 2025 09:52:51 -0700 Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Mailer: b4 0.14.3 On Thu, 04 Dec 2025 15:54:50 -0800, Joanne Koong wrote: > buf->addr and buf->len reside in memory shared with userspace. They > should be written with WRITE_ONCE() to guarantee atomic stores and > prevent tearing or other unsafe compiler optimizations. > > Applied, thanks! [1/1] io_uring/kbuf: use WRITE_ONCE() for userspace-shared buffer ring fields commit: a4c694bfc2455e82b7caf6045ca893d123e0ed11 Best regards, -- Jens Axboe