From patchwork Thu Mar 9 16:00:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Zimmermann X-Patchwork-Id: 13167768 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16812C7618A for ; Thu, 9 Mar 2023 16:02:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231460AbjCIQCM (ORCPT ); Thu, 9 Mar 2023 11:02:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47218 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230288AbjCIQCI (ORCPT ); Thu, 9 Mar 2023 11:02:08 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08B35F4B43; Thu, 9 Mar 2023 08:02:05 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 6BE3422143; Thu, 9 Mar 2023 16:02:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1678377724; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=JSy3IOe6HAwVADCc+hI/Uqf0bdfoESCu+tTk0BOF+MI=; b=bz6qb5Bx+kU6fy0DFJbxLODvavLeoLYfrzPhmOW97GSASjQRENThgOtkikza8AonRjLEQt VivNH1ZGrAtanmx/1nvdrWvKpcklJsLhopsdlO1oqE1E2Q89r2fVzrienGO/l7Vgq8iaD9 4zv0CpykPLR0A/c2eQ86nhFq9hg/8M8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1678377724; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=JSy3IOe6HAwVADCc+hI/Uqf0bdfoESCu+tTk0BOF+MI=; b=llMqymtgLc4cOviOVHdyzcRHtQ68ua2MXLLsY8y3soHCsPeOViZQmNAQQMsy09U8KYaLuf tnkykul4AHXu9tBA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 0B40C1391B; Thu, 9 Mar 2023 16:02:04 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id go3iAfwCCmQHbgAAMHmgww (envelope-from ); Thu, 09 Mar 2023 16:02:04 +0000 From: Thomas Zimmermann To: deller@gmx.de, geert+renesas@glider.be, timur@kernel.org, rdunlap@infradead.org, paulus@samba.org, benh@kernel.crashing.org, linux@armlinux.org.uk, pjones@redhat.com, adaplas@gmail.com, s.hauer@pengutronix.de, shawnguo@kernel.org, mbroemme@libmpq.org, thomas@winischhofer.net, James.Bottomley@HansenPartnership.com, sudipm.mukherjee@gmail.com, teddy.wang@siliconmotion.com, corbet@lwn.net Cc: linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Thomas Zimmermann Subject: [PATCH v2 000/101] fbdev: Fix memory leak in option parsing Date: Thu, 9 Mar 2023 17:00:20 +0100 Message-Id: <20230309160201.5163-1-tzimmermann@suse.de> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Introduce struct option_iter and helpers to parse command-line options with comma-separated key-value pairs. Then convert fbdev drivers to the new interface. Fixes a memory leak in the parsing of the video= option. Before commit 73ce73c30ba9 ("fbdev: Transfer video= option strings to caller; clarify ownership"), a call to fb_get_options() either returned an internal string or a duplicated string; hence ownership of the string's memory buffer was not well defined, but depended on how users specified the video= option on the kernel command line. For global settings, the caller owned the returned memory and for per-driver settings, fb_get_options() owned the memory. As calling drivers were unable to detect the case, they had no option but to leak the the memory. Commit 73ce73c30ba9 ("fbdev: Transfer video= option strings to caller; clarify ownership") changed semantics to caller-owned strings. Drivers still leaked the memory, but at least ownership was clear. This patchset fixes the memory leak and changes string ownership back to fb_get_options(). Patch 1 introduces struct option_iter and a few helpers. The interface takes an option string, such as video=, in the common form value1,key2:value2,value3 etc and returns the individual comma-separated pairs. Various modules use this pattern, so the code is located under lib/. Patches 2 to 100 go through fbdev drivers and convert them to the new interface. This often requires a number of cleanups. A driver would typically refer to the option string's video mode. Such strings are now copied to driver-allocated memory so that drivers don't refer directly to the option string's memory. The option iterator then replaces manual parsing loops based on strsep(","). All driver-allocated memory is released by removing the device or unloading the module. Patch 101 finally changes the ownership of the option string to be internal to fb_get_option(); thereby fixing the memory leak. The option iterator holds its own copy of the string and is not affected by the change. Most fbdev drivers only support to parse option strings if they are built-in. I assume that's because of the original fuzzy semantics of fb_get_options(). A later patchset could change the driver to respect video= settings in any configuration. v2: * use kstrdup()/kfree() for video strings (Geert, Timur) * fix iterator docs (Randy) * update iterator interface Thomas Zimmermann (101): lib: Add option iterator fbdev/68328fb: Remove trailing whitespaces fbdev/68328fb: Remove unused option string fbdev/acornfb: Only init fb_info once fbdev/acornfb: Parse option string with struct option_iter fbdev/amifb: Duplicate video-mode option string fbdev/amifb: Parse option string with struct option_iter fbdev/arkfb: Duplicate video-mode option string fbdev/atafb: Duplicate video-mode option string fbdev/atafb: Parse option string with struct option_iter fbdev/aty: Duplicate video-mode option string fbdev/aty: Parse option string with struct option_iter fbdev/au1100fb: Parse option string with struct option_iter fbdev/au1200fb: Parse option string with struct option_iter fbdev/cirrusfb: Duplicate video-mode option string fbdev/cirrusfb: Parse option string with struct option_iter fbdev/controlfb: Remove trailing whitespaces fbdev/controlfb: Parse option string with struct option_iter fbdev/cyber2000fb: Parse option string with struct option_iter fbdev/efifb: Parse option string with struct option_iter fbdev/fm2fb: Parse option string with struct option_iter fbdev/fsl-diu-fb: Duplicate video-mode option string fbdev/fsl-diu-fb: Parse option string with struct option_iter fbdev/gbefb: Duplicate video-mode option string fbdev/gbefb: Parse option string with struct option_iter fbdev/geode: Duplicate video-mode option string fbdev/geode: Parse option string with struct option_iter fbdev/grvga: Duplicate video-mode option string fbdev/grvga: Parse option string with struct option_iter fbdev/gxt4500: Duplicate video-mode option string fbdev/hyperv_fb: Duplicate video-mode option string fbdev/i740fb: Duplicate video-mode option string fbdev/i740fb: Parse option string with struct option_iter fbdev/i810: Duplicate video-mode option string fbdev/i810: Parse option string with struct option_iter fbdev/imsttfb: Parse option string with struct option_iter fbdev/intelfb: Duplicate video-mode option string fbdev/intelfb: Parse option string with struct option_iter fbdev/imxfb: Duplicate video-mode option string fbdev/imxfb: Parse option string with struct option_iter fbdev/kyrofb: Duplicate video-mode option string fbdev/kyrofb: Parse option string with struct option_iter fbdev/macfb: Remove trailing whitespaces fbdev/macfb: Parse option string with struct option_iter fbdev/matroxfb: Parse option string with struct option_iter fbdev/mx3fb: Duplicate video-mode option string fbdev/mx3fb: Parse option string with struct option_iter fbdev/neofb: Duplicate video-mode option string fbdev/neofb: Parse option string with struct option_iter fbdev/nvidiafb: Duplicate video-mode option string fbdev/nvidiafb: Parse option string with struct option_iter fbdev/ocfb: Duplicate video-mode option string fbdev/ocfb: Parse option string with struct option_iter fbdev/omapfb: Parse option string with struct option_iter fbdev/platinumfb: Remove trailing whitespaces fbdev/platinumfb: Parse option string with struct option_iter fbdev/pm2fb: Duplicate video-mode option string fbdev/pm2fb: Parse option string with struct option_iter fbdev/pm3fb: Duplicate video-mode option string fbdev/pm3fb: Parse option string with struct option_iter fbdev/ps3fb: Duplicate video-mode option string fbdev/ps3fb: Parse option string with struct option_iter fbdev/pvr2fb: Duplicate video-mode option string fbdev/pvr2fb: Parse option string with struct option_iter fbdev/pxafb: Parse option string with struct option_iter fbdev/rivafb: Duplicate video-mode option string fbdev/rivafb: Parse option string with struct option_iter fbdev/s3fb: Duplicate video-mode option string fbdev/s3fb: Parse option string with struct option_iter fbdev/savagefb: Duplicate video-mode option string fbdev/savagefb: Parse option string with struct option_iter fbdev/sisfb: Constify mode string fbdev/sisfb: Parse option string with struct option_iter fbdev/skeletonfb: Parse option string with struct option_iter fbdev/sm712fb: Duplicate video-mode option string fbdev/sstfb: Duplicate video-mode option string fbdev/sstfb: Parse option string with struct option_iter fbdev/stifb: Remove trailing whitespaces fbdev/stifb: Constify option string fbdev/tdfxfb: Duplicate video-mode option string fbdev/tdfxfb: Parse option string with struct option_iter fbdev/tgafb: Duplicate video-mode option string fbdev/tgafb: Parse option string with struct option_iter fbdev/tmiofb: Remove unused option string fbdev/tridentfb: Duplicate video-mode option string fbdev/tridentfb: Parse option string with struct option_iter fbdev/uvesafb: Duplicate video-mode option string fbdev/uvesafb: Parse option string with struct option_iter fbdev/valkyriefb: Remove trailing whitespaces fbdev/valkyriefb: Parse option string with struct option_iter fbdev/vermilion: Remove unused option string fbdev/vesafb: Parse option string with struct option_iter fbdev/vfb: Remove trailing whitespaces fbdev/vfb: Duplicate video-mode option string fbdev/vfb: Parse option string with struct option_iter fbdev/viafb: Parse option string with struct option_iter fbdev/vt8623fb: Duplicate video-mode option string staging/sm750fb: Release g_settings in module-exit function staging/sm750fb: Duplicate video-mode option string staging/sm750fb: Parse option string with struct option_iter fbdev: Constify option strings Documentation/core-api/kernel-api.rst | 9 ++ drivers/staging/sm750fb/sm750.c | 63 ++++---- drivers/video/fbdev/68328fb.c | 24 +-- drivers/video/fbdev/acornfb.c | 23 ++- drivers/video/fbdev/amifb.c | 23 +-- drivers/video/fbdev/arkfb.c | 10 +- drivers/video/fbdev/atafb.c | 21 +-- drivers/video/fbdev/aty/aty128fb.c | 22 ++- drivers/video/fbdev/aty/atyfb_base.c | 23 ++- drivers/video/fbdev/aty/radeon_base.c | 26 +-- drivers/video/fbdev/au1100fb.c | 13 +- drivers/video/fbdev/au1200fb.c | 15 +- drivers/video/fbdev/cirrusfb.c | 30 ++-- drivers/video/fbdev/controlfb.c | 47 +++--- drivers/video/fbdev/core/fb_cmdline.c | 13 +- drivers/video/fbdev/core/modedb.c | 8 +- drivers/video/fbdev/cyber2000fb.c | 17 +- drivers/video/fbdev/efifb.c | 44 ++--- drivers/video/fbdev/ep93xx-fb.c | 2 +- drivers/video/fbdev/fm2fb.c | 14 +- drivers/video/fbdev/fsl-diu-fb.c | 24 +-- drivers/video/fbdev/gbefb.c | 23 +-- drivers/video/fbdev/geode/gx1fb_core.c | 16 +- drivers/video/fbdev/geode/gxfb_core.c | 23 +-- drivers/video/fbdev/geode/lxfb_core.c | 25 +-- drivers/video/fbdev/grvga.c | 18 ++- drivers/video/fbdev/gxt4500.c | 13 +- drivers/video/fbdev/hyperv_fb.c | 18 ++- drivers/video/fbdev/i740fb.c | 26 +-- drivers/video/fbdev/i810/i810_main.c | 26 ++- drivers/video/fbdev/imsttfb.c | 16 +- drivers/video/fbdev/imxfb.c | 21 +-- drivers/video/fbdev/intelfb/intelfbdrv.c | 23 ++- drivers/video/fbdev/kyro/fbdev.c | 21 ++- drivers/video/fbdev/macfb.c | 26 +-- drivers/video/fbdev/matrox/matroxfb_base.c | 19 +-- drivers/video/fbdev/mx3fb.c | 23 ++- drivers/video/fbdev/neofb.c | 26 +-- drivers/video/fbdev/nvidia/nvidia.c | 26 ++- drivers/video/fbdev/ocfb.c | 21 ++- drivers/video/fbdev/omap/omapfb_main.c | 15 +- drivers/video/fbdev/platinumfb.c | 44 ++--- drivers/video/fbdev/pm2fb.c | 25 +-- drivers/video/fbdev/pm3fb.c | 27 ++-- drivers/video/fbdev/ps3fb.c | 28 ++-- drivers/video/fbdev/pvr2fb.c | 32 ++-- drivers/video/fbdev/pxafb.c | 18 ++- drivers/video/fbdev/riva/fbdev.c | 26 ++- drivers/video/fbdev/s3fb.c | 27 ++-- drivers/video/fbdev/savage/savagefb_driver.c | 20 ++- drivers/video/fbdev/sis/sis_main.c | 24 +-- drivers/video/fbdev/skeletonfb.c | 17 +- drivers/video/fbdev/sm712fb.c | 12 +- drivers/video/fbdev/sstfb.c | 25 +-- drivers/video/fbdev/stifb.c | 162 +++++++++---------- drivers/video/fbdev/tdfxfb.c | 21 ++- drivers/video/fbdev/tgafb.c | 30 ++-- drivers/video/fbdev/tmiofb.c | 24 +-- drivers/video/fbdev/tridentfb.c | 27 ++-- drivers/video/fbdev/uvesafb.c | 21 ++- drivers/video/fbdev/valkyriefb.c | 30 ++-- drivers/video/fbdev/vermilion/vermilion.c | 7 +- drivers/video/fbdev/vesafb.c | 16 +- drivers/video/fbdev/vfb.c | 35 ++-- drivers/video/fbdev/via/viafbdev.c | 15 +- drivers/video/fbdev/vt8623fb.c | 11 +- include/linux/cmdline.h | 36 +++++ include/linux/fb.h | 2 +- lib/Makefile | 2 +- lib/cmdline_iter.c | 109 +++++++++++++ 70 files changed, 1087 insertions(+), 682 deletions(-) create mode 100644 include/linux/cmdline.h create mode 100644 lib/cmdline_iter.c