{"id":14870,"url":"https://patchwork.libcamera.org/api/1.1/patches/14870/?format=json","web_url":"https://patchwork.libcamera.org/patch/14870/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/1.1/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20211130033820.18235-17-laurent.pinchart@ideasonboard.com>","date":"2021-11-30T03:38:14","name":"[libcamera-devel,v4,16/22] libcamera: v4l2_videodevice: Pass SharedFD to open()","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"5970720741f3d1b4fc62f290bf7221ea18402ff3","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/1.1/people/2/?format=json","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"delegate":{"id":14,"url":"https://patchwork.libcamera.org/api/1.1/users/14/?format=json","username":"pinchartl","first_name":"Laurent","last_name":"Pinchart","email":"laurent.pinchart@ideasonboard.com"},"mbox":"https://patchwork.libcamera.org/patch/14870/mbox/","series":[{"id":2776,"url":"https://patchwork.libcamera.org/api/1.1/series/2776/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=2776","date":"2021-11-30T03:37:58","name":"libcamera: Introduce UniqueFD","version":4,"mbox":"https://patchwork.libcamera.org/series/2776/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/14870/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/14870/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id BC66EC3251\n\tfor ;\n\tTue, 30 Nov 2021 03:39:12 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 6397D605C2;\n\tTue, 30 Nov 2021 04:39:12 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 21AB5605BA\n\tfor ;\n\tTue, 30 Nov 2021 04:38:56 +0100 (CET)","from pendragon.lan (62-78-145-57.bb.dnainternet.fi [62.78.145.57])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id B05C211FB\n\tfor ;\n\tTue, 30 Nov 2021 04:38:55 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"bHsiojhX\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1638243535;\n\tbh=SeyzkNKxBvNqGt6W5rdjec51yqCbeLJdUCINRKHg0p4=;\n\th=From:To:Subject:Date:In-Reply-To:References:From;\n\tb=bHsiojhXi2dqgNmbHtzO1WAatEXC7o48XxScwkT80UP1piDQoQFc/o9So9BiN0gXY\n\tCkVh7kJl/3WVHmHngkHKOpph8IUrvvkqLKAT0HoK4GKh/0NsczJ8bDJnY8CexnyUj0\n\tylyD3pFotNpzWG1HmtL6jQ9kgr7/OltEap9USmfY=","From":"Laurent Pinchart ","To":"libcamera-devel@lists.libcamera.org","Date":"Tue, 30 Nov 2021 05:38:14 +0200","Message-Id":"<20211130033820.18235-17-laurent.pinchart@ideasonboard.com>","X-Mailer":"git-send-email 2.32.0","In-Reply-To":"<20211130033820.18235-1-laurent.pinchart@ideasonboard.com>","References":"<20211130033820.18235-1-laurent.pinchart@ideasonboard.com>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH v4 16/22] libcamera: v4l2_videodevice:\n\tPass SharedFD to open()","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"The V4L2VideoDevice::open() function that takes an open file handle\nduplicates it internally, and leaves the original handle untouched. This\nis documented but not enforced through language constructs. Fix it by\npassing a SharedFD to the function.\n\nSigned-off-by: Laurent Pinchart \n---\n include/libcamera/internal/v4l2_videodevice.h | 2 +-\n src/libcamera/v4l2_videodevice.cpp | 22 ++++++++-----------\n 2 files changed, 10 insertions(+), 14 deletions(-)","diff":"diff --git a/include/libcamera/internal/v4l2_videodevice.h b/include/libcamera/internal/v4l2_videodevice.h\nindex 80b665771782..9f556f99587c 100644\n--- a/include/libcamera/internal/v4l2_videodevice.h\n+++ b/include/libcamera/internal/v4l2_videodevice.h\n@@ -184,7 +184,7 @@ public:\n \t~V4L2VideoDevice();\n \n \tint open();\n-\tint open(int handle, enum v4l2_buf_type type);\n+\tint open(FileDescriptor handle, enum v4l2_buf_type type);\n \tvoid close();\n \n \tconst char *driverName() const { return caps_.driver(); }\ndiff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp\nindex 3966483a365f..5f1cc6e2f47f 100644\n--- a/src/libcamera/v4l2_videodevice.cpp\n+++ b/src/libcamera/v4l2_videodevice.cpp\n@@ -612,16 +612,14 @@ int V4L2VideoDevice::open()\n * its type from the capabilities. This can be used to force a given device type\n * for memory-to-memory devices.\n *\n- * The file descriptor \\a handle is duplicated, and the caller is responsible\n- * for closing the \\a handle when it has no further use for it. The close()\n- * function will close the duplicated file descriptor, leaving \\a handle\n- * untouched.\n+ * The file descriptor \\a handle is duplicated, no reference to the original\n+ * handle is kept.\n *\n * \\return 0 on success or a negative error code otherwise\n */\n-int V4L2VideoDevice::open(int handle, enum v4l2_buf_type type)\n+int V4L2VideoDevice::open(FileDescriptor handle, enum v4l2_buf_type type)\n {\n-\tUniqueFD newFd(dup(handle));\n+\tUniqueFD newFd = handle.dup();\n \tif (!newFd.isValid()) {\n \t\tLOG(V4L2, Error) << \"Failed to duplicate file handle: \"\n \t\t\t\t << strerror(errno);\n@@ -1900,12 +1898,10 @@ int V4L2M2MDevice::open()\n \n \t/*\n \t * The output and capture V4L2VideoDevice instances use the same file\n-\t * handle for the same device node. The local file handle can be closed\n-\t * as the V4L2VideoDevice::open() retains a handle by duplicating the\n-\t * fd passed in.\n+\t * handle for the same device node.\n \t */\n-\tUniqueFD fd(syscall(SYS_openat, AT_FDCWD, deviceNode_.c_str(),\n-\t\t\t O_RDWR | O_NONBLOCK));\n+\tFileDescriptor fd(syscall(SYS_openat, AT_FDCWD, deviceNode_.c_str(),\n+\t\t\t\t O_RDWR | O_NONBLOCK));\n \tif (!fd.isValid()) {\n \t\tret = -errno;\n \t\tLOG(V4L2, Error) << \"Failed to open V4L2 M2M device: \"\n@@ -1913,11 +1909,11 @@ int V4L2M2MDevice::open()\n \t\treturn ret;\n \t}\n \n-\tret = output_->open(fd.get(), V4L2_BUF_TYPE_VIDEO_OUTPUT);\n+\tret = output_->open(fd, V4L2_BUF_TYPE_VIDEO_OUTPUT);\n \tif (ret)\n \t\tgoto err;\n \n-\tret = capture_->open(fd.get(), V4L2_BUF_TYPE_VIDEO_CAPTURE);\n+\tret = capture_->open(fd, V4L2_BUF_TYPE_VIDEO_CAPTURE);\n \tif (ret)\n \t\tgoto err;\n \n","prefixes":["libcamera-devel","v4","16/22"]}