From patchwork Tue Mar 25 18:08:20 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= X-Patchwork-Id: 23019 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id 7696CC3323 for ; Tue, 25 Mar 2025 18:09:04 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 457E96895F; Tue, 25 Mar 2025 19:09:02 +0100 (CET) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="tgJt/Ixy"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 757686895F for ; Tue, 25 Mar 2025 19:08:48 +0100 (CET) Received: from pb-laptop.local (185.221.143.221.nat.pool.zt.hu [185.221.143.221]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id CBBCA353 for ; Tue, 25 Mar 2025 19:07:00 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1742926021; bh=qRGu2Bth2fPbi9yFuKL/gq8+YmejefhAxhWGC8edVHY=; h=From:To:Subject:Date:In-Reply-To:References:From; b=tgJt/IxyH+HoYo8B9gSiBwdT33Wg1OCoGywhJIkdtifW6Sdszs9+gpJbCEZtbEy85 YmogVyQEd8d+noYk8+tfRdQ+hD38KGYOhvGb39sv51XPZ2wAdUECFlM9XkSqxO2i4C tRYllR+LBJFYAtl5Dv9zrpuBe4XJp3zQDUF3keWA= From: =?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= To: libcamera-devel@lists.libcamera.org Subject: [RFC PATCH v3 8/9] libcamera: process: Use `close_range()` when available Date: Tue, 25 Mar 2025 19:08:20 +0100 Message-ID: <20250325180821.1456154-9-barnabas.pocze@ideasonboard.com> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250325180821.1456154-1-barnabas.pocze@ideasonboard.com> References: <20250325180821.1456154-1-barnabas.pocze@ideasonboard.com> MIME-Version: 1.0 X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" Use the `close_range()` system call when available as it is simpler and faster than iterating `/proc/self/fd/`. Signed-off-by: Barnabás Pőcze Reviewed-by: Laurent Pinchart --- meson.build | 4 ++++ src/libcamera/process.cpp | 20 ++++++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/meson.build b/meson.build index 668ec3969..00291d628 100644 --- a/meson.build +++ b/meson.build @@ -103,6 +103,10 @@ if cc.has_header_symbol('stdlib.h', 'secure_getenv', prefix : '#define _GNU_SOUR config_h.set('HAVE_SECURE_GETENV', 1) endif +if cc.has_header_symbol('unistd.h', 'close_range', prefix : '#define _GNU_SOURCE') + config_h.set('HAVE_CLOSE_RANGE', 1) +endif + common_arguments = [ '-Wmissing-declarations', '-Wshadow', diff --git a/src/libcamera/process.cpp b/src/libcamera/process.cpp index 01503e485..5fa813300 100644 --- a/src/libcamera/process.cpp +++ b/src/libcamera/process.cpp @@ -70,6 +70,26 @@ void closeAllFdsExcept(Span fds) ASSERT(v.empty() || v.front() >= 0); +#if HAVE_CLOSE_RANGE + static const bool hasCloseRange = [] { + return close_range(~0u, 0, 0) < 0 && errno == EINVAL; + }(); + + if (hasCloseRange) { + unsigned int prev = 0; + + for (unsigned int curr : v) { + ASSERT(prev <= curr); + if (prev < curr) + close_range(prev, curr - 1, 0); + prev = curr + 1; + } + + close_range(prev, ~0u, 0); + return; + } +#endif + DIR *dir = opendir("/proc/self/fd"); if (!dir) return;