{"id":23250,"url":"https://patchwork.libcamera.org/api/1.1/patches/23250/?format=json","web_url":"https://patchwork.libcamera.org/patch/23250/","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":"<20250424112203.445351-9-barnabas.pocze@ideasonboard.com>","date":"2025-04-24T11:22:01","name":"[RFC,v4,8/9] libcamera: process: Use `close_range()` when available","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"bf73690ebeca93ae5e204b867694bd8ba03ecba2","submitter":{"id":216,"url":"https://patchwork.libcamera.org/api/1.1/people/216/?format=json","name":"Barnabás Pőcze","email":"barnabas.pocze@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/23250/mbox/","series":[{"id":5144,"url":"https://patchwork.libcamera.org/api/1.1/series/5144/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5144","date":"2025-04-24T11:21:53","name":"libcamera: process: Remove `ProcessManager` singleton","version":4,"mbox":"https://patchwork.libcamera.org/series/5144/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/23250/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/23250/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 54121C3323\n\tfor ;\n\tThu, 24 Apr 2025 11:22:28 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id E277968B26;\n\tThu, 24 Apr 2025 13:22:22 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 25A1268AD7\n\tfor ;\n\tThu, 24 Apr 2025 13:22:09 +0200 (CEST)","from pb-laptop.local (185.221.143.16.nat.pool.zt.hu\n\t[185.221.143.16])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 20129F01;\n\tThu, 24 Apr 2025 13:22:07 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"q/x6otVe\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1745493727;\n\tbh=yERMYMCMd6M3R7agseyITlcqSb9qdaTssWxyeDjLHNI=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=q/x6otVefyB2Wqr+DjISz7zD2SLilgydpjoYm1BUbZ7Cz9AxDJmP3wSlYAhnxufnt\n\thV33rLlz2thybrqKOoWzBAF2GZKOZriH39ESc8EkEK3u2JrrmZTyMX5K9AU557NeF/\n\tpUdzGg1lTxGT6K/8c20m9g9D6OZi9c74rAUFpICw=","From":"=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= ","To":"libcamera-devel@lists.libcamera.org","Cc":"Laurent Pinchart ","Subject":"[RFC PATCH v4 8/9] libcamera: process: Use `close_range()` when\n\tavailable","Date":"Thu, 24 Apr 2025 13:22:01 +0200","Message-ID":"<20250424112203.445351-9-barnabas.pocze@ideasonboard.com>","X-Mailer":"git-send-email 2.49.0","In-Reply-To":"<20250424112203.445351-1-barnabas.pocze@ideasonboard.com>","References":"<20250424112203.445351-1-barnabas.pocze@ideasonboard.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=UTF-8","Content-Transfer-Encoding":"8bit","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":"Use the `close_range()` system call when available as it is simpler\nand faster than iterating `/proc/self/fd/`.\n\nSigned-off-by: Barnabás Pőcze \nReviewed-by: Laurent Pinchart \n---\n meson.build | 4 ++++\n src/libcamera/process.cpp | 25 +++++++++++++++++++++++++\n 2 files changed, 29 insertions(+)","diff":"diff --git a/meson.build b/meson.build\nindex e9d6187b3..1525bdf4a 100644\n--- a/meson.build\n+++ b/meson.build\n@@ -74,6 +74,10 @@ cc = meson.get_compiler('c')\n cxx = meson.get_compiler('cpp')\n config_h = configuration_data()\n \n+if cc.has_header_symbol('unistd.h', 'close_range', prefix : '#define _GNU_SOURCE')\n+ config_h.set('HAVE_CLOSE_RANGE', 1)\n+endif\n+\n if cc.has_header_symbol('fcntl.h', 'F_ADD_SEALS', prefix : '#define _GNU_SOURCE')\n config_h.set('HAVE_FILE_SEALS', 1)\n endif\ndiff --git a/src/libcamera/process.cpp b/src/libcamera/process.cpp\nindex 369fdb12d..42b56374d 100644\n--- a/src/libcamera/process.cpp\n+++ b/src/libcamera/process.cpp\n@@ -70,6 +70,31 @@ void closeAllFdsExcept(Span fds)\n \n \tASSERT(v.empty() || v.front() >= 0);\n \n+#if HAVE_CLOSE_RANGE\n+\t/*\n+\t * At the moment libcamera does not require at least Linux 5.9,\n+\t * which introduced the `close_range()` system call, so a runtime\n+\t * check is also needed to make sure that it is supported.\n+\t */\n+\tstatic const bool hasCloseRange = [] {\n+\t\treturn close_range(~0u, 0, 0) < 0 && errno == EINVAL;\n+\t}();\n+\n+\tif (hasCloseRange) {\n+\t\tunsigned int prev = 0;\n+\n+\t\tfor (unsigned int curr : v) {\n+\t\t\tASSERT(prev <= curr + 1);\n+\t\t\tif (prev < curr)\n+\t\t\t\tclose_range(prev, curr - 1, 0);\n+\t\t\tprev = curr + 1;\n+\t\t}\n+\n+\t\tclose_range(prev, ~0u, 0);\n+\t\treturn;\n+\t}\n+#endif\n+\n \tDIR *dir = opendir(\"/proc/self/fd\");\n \tif (!dir)\n \t\treturn;\n","prefixes":["RFC","v4","8/9"]}