From owner-freebsd-drivers@freebsd.org Fri Mar 20 14:40:15 2020 Return-Path: Delivered-To: freebsd-drivers@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 9B97726902E; Fri, 20 Mar 2020 14:40:15 +0000 (UTC) (envelope-from babupalit@gmail.com) Received: from mail-ot1-x342.google.com (mail-ot1-x342.google.com [IPv6:2607:f8b0:4864:20::342]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 48kRJb1kj7z3N9n; Fri, 20 Mar 2020 14:40:15 +0000 (UTC) (envelope-from babupalit@gmail.com) Received: by mail-ot1-x342.google.com with SMTP id e19so6163420otj.7; Fri, 20 Mar 2020 07:40:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=C0BBlLo5NKEYES2/88dE/bqmWYYFQUw8vhfYt7tEClM=; b=in9qgLku5KbTsoXqi+qNSJsDE/Gyy5l62O9YvXaEWb8e+3rQatJKRhOLfX9OG9orMt GRYS80g2puGt9k0okHa6tMOa/NEVbGa14H5gv/Bp3I2He17NXNCtwc4iQpTwfl+X0IJ2 3cUPZzJSNBHe3WyRXUmm7be2hEacwJmK4EYsIOA9mL4EP60abrUeZRs7fhCfd6lPstQw Fna2jVHlgILi60mpmmBFJJ8njIAAK6X04qtmjFnf4NF1w7a14qwTXUAF5x4WuiZDZmOe iQcHEFYL57eSi8QOMrv2+WlKb1RH8pTTRKhwlojHESuW+uIlHw0TTxwyXIi+ajP4GL99 h5aw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=C0BBlLo5NKEYES2/88dE/bqmWYYFQUw8vhfYt7tEClM=; b=e/mlHNqZUhZ9JrUQ9itaUY5Kov6bWVdVzXgzdN/e1YXnsVHf65izp9S1BluAhQbQN3 rijoi0PYKu2CxaYOIaKE58McZ9SwNJTshuyne21+lX13ueoA46nfff0/yeo/7natDQGg 9dDj83kbwcFqfOi5OOiVmCG44ykJfQZmTr5/uXIZGYFLPfVj+ya9SBNxLpLakGuvMoiE tFb3/4sKCZRDzMpVhzSlphoW/6vPNnwsNjgY0k/Xc58QsK709zJKx2tcasWJvC7sI6k7 dJDcbrdJX7g60vKYHphXLuEjMxGVUn5Ieb0JsP3tkxB9jR9m8HuOdEl0GqiXXba4lHv0 U7+A== X-Gm-Message-State: ANhLgQ1qZMixBDwV2wPrPzXV0H9FOrwq7WALBTUOI6SbtJZA4nqi3kmw K/jiQqBFECFDSjOOgWV1kHO8NgL9CpHZGMiWViuqv+jj X-Google-Smtp-Source: ADFU+vsAu73irrNS4ryUj/BKHgy9A59G73DlBtLk2mHzswggQPJypHKYuPdiEnnHYgsBfK+g7Bx2Xog/IZlT9r8+0tw= X-Received: by 2002:a05:6830:1251:: with SMTP id s17mr7331035otp.75.1584715214277; Fri, 20 Mar 2020 07:40:14 -0700 (PDT) MIME-Version: 1.0 From: Arpan Palit Date: Fri, 20 Mar 2020 20:10:02 +0530 Message-ID: Subject: How to access a user space file from kernel space in FreeBSD. To: freebsd-hackers@freebsd.org, freebsd-questions@freebsd.org, freebsd-drivers@freebsd.org X-Rspamd-Queue-Id: 48kRJb1kj7z3N9n X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=in9qgLku; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of babupalit@gmail.com designates 2607:f8b0:4864:20::342 as permitted sender) smtp.mailfrom=babupalit@gmail.com X-Spamd-Result: default: False [-3.00 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36:c]; FREEMAIL_FROM(0.00)[gmail.com]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; TO_DN_NONE(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; IP_SCORE_FREEMAIL(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; IP_SCORE(0.00)[ip: (1.92), ipnet: 2607:f8b0::/32(-1.20), asn: 15169(-1.24), country: US(-0.05)]; DKIM_TRACE(0.00)[gmail.com:+]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; RCVD_IN_DNSWL_NONE(0.00)[2.4.3.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.4.6.8.4.0.b.8.f.7.0.6.2.list.dnswl.org : 127.0.5.0]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com.dwl.dnswl.org : 127.0.5.0] Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: freebsd-drivers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Writing device drivers for FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 20 Mar 2020 14:40:15 -0000 Hi all, I am working on (kernel)driver ioctl implementation for file read/write, where I need to know what are API's which can expose to read,write and close user space file from kernel space. In general I need to know the answer for the below questions. i). How to open a user space file from driver(kernel space) ? ii). How to create a new user space file from driver(kernel space) ? iii). How to get file parameters like size of the file ? iv). How to read/write the files from the driver(kernel space) ? Thanks & Regards, Arpan Palit