From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41941C04AAF for ; Mon, 20 May 2019 08:22:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02DAF20815 for ; Mon, 20 May 2019 08:22:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="TrKawzUN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731391AbfETIWp (ORCPT ); Mon, 20 May 2019 04:22:45 -0400 Received: from mail-ed1-f66.google.com ([209.85.208.66]:34371 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730701AbfETIWo (ORCPT ); Mon, 20 May 2019 04:22:44 -0400 Received: by mail-ed1-f66.google.com with SMTP id p27so22585944eda.1 for ; Mon, 20 May 2019 01:22:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=eM35EBMx+LqeeuwxYimZRbsx1yQ6Wi7o1I3eNH/ML70=; b=TrKawzUNypCoohtGwlMufk2BVzGw5z44FIudIvWF1khrdzBTe5O/VSS/NUwt0qtdLK NuElr8o2M8sRvFprt6j0hB8KF2AT2v9SKW5Za9P9xqlhMRofRF+A5OdeapjH6FnH4O2U kPpzA5J6kyB+1e0eW5+uIT5Bv9onoDI2q2eNE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=eM35EBMx+LqeeuwxYimZRbsx1yQ6Wi7o1I3eNH/ML70=; b=n1WnTsrzY3pzynyN48x87omSw+CPJsdjryaKNAu7T6QbesODFGOVleX2CVLAiF51EG MUg7yyt8trQdR7DnakxPR2WOvXhohlBR6RZFpZZmx8I57AhTG5arOJ4IiYFnTeDAD2BI cLaeoV0WQ8tHQpxRlI3CQzWtPNhm/6iX1vFlvXM5+AtWTTj1iX5VaRC3Vn7Hye4wP4JF VGSB8dYJD35xJ6V8qME5CjlMVmLXZuh9O5bUzN3XHQoA5poqIMorlxFlLKG3AZeMhqSP vfexxAHQon7ehrnXiszVS6q44SmF/YXF+nyhbuw+Mv6EMH1OWMorpQf+VHcFPa/j5UMY P65Q== X-Gm-Message-State: APjAAAXuOOb4eGLN3OpfI+l1Wv9YaoJhzJT2bwgaxunwidorlqQK+/Sf KzHXiNyIWVpKnuzuEIDotW4IVA== X-Google-Smtp-Source: APXvYqzwxqr5riknzKLKn3+LJQycV1xHBYyDBHu6NKNup3To1CmBLLwIazOhp9s/VmgG+UQqgYb6ww== X-Received: by 2002:a17:906:2ad5:: with SMTP id m21mr19708324eje.55.1558340561296; Mon, 20 May 2019 01:22:41 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:569e:0:3106:d637:d723:e855]) by smtp.gmail.com with ESMTPSA id t25sm3021263ejx.8.2019.05.20.01.22.40 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 20 May 2019 01:22:40 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , LKML , Daniel Vetter , Daniel Vetter , Bartlomiej Zolnierkiewicz , Hans de Goede , Yisheng Xie , Sergey Senozhatsky , =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= , Peter Rosin , =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= , Mikulas Patocka , "Gustavo A. R. Silva" , linux-fbdev@vger.kernel.org Subject: [PATCH 16/33] fbdev: lock_fb_info cannot fail Date: Mon, 20 May 2019 10:21:59 +0200 Message-Id: <20190520082216.26273-17-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190520082216.26273-1-daniel.vetter@ffwll.ch> References: <20190520082216.26273-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ever since commit c47747fde931c02455683bd00ea43eaa62f35b0e Author: Linus Torvalds Date: Wed May 11 14:58:34 2011 -0700 fbmem: make read/write/ioctl use the frame buffer at open time fbdev has gained proper refcounting for the fbinfo attached to any open files, which means that the backing driver (stored in fb_info->fbops) cannot untimely disappear anymore. The only thing that can happen is that the entire device just outright disappears and gets unregistered, but file_fb_info does check for that. Except that it's racy - it only checks once at the start of a file_ops, there's no guarantee that the underlying fbdev won't untimely disappear. Aside: A proper way to fix that race is probably to replicate the srcu trickery we've rolled out in drm. But given that this race has existed since forever it's probably not one we need to fix right away. do_unregister_framebuffer also nowhere clears fb_info->fbops, hence the check in lock_fb_info can't possible catch a disappearing fbdev later on. Long story short: Ever since the above commit the fb_info->fbops checks have essentially become dead code. Remove this all. Aside from the file_ops callbacks, and stuff called from there there's only register/unregister code left. If that goes wrong a driver managed to register/unregister a device instance twice or in the wrong order. That's just a driver bug. v2: - fb_mmap had an open-coded version of the fbinfo->fops check, because it doesn't need the fbinfo->lock. Delete that too. - Use the wrapper function in fb_open/release now, since no difference anymore. Signed-off-by: Daniel Vetter Cc: Bartlomiej Zolnierkiewicz Cc: Daniel Vetter Cc: Hans de Goede Cc: Yisheng Xie Cc: Sergey Senozhatsky Cc: "Noralf Trønnes" Cc: Peter Rosin Cc: "Michał Mirosław" Cc: Mikulas Patocka Cc: "Gustavo A. R. Silva" Cc: linux-fbdev@vger.kernel.org --- drivers/video/fbdev/core/fbcmap.c | 6 +-- drivers/video/fbdev/core/fbcon.c | 3 +- drivers/video/fbdev/core/fbmem.c | 73 +++++++------------------------ include/linux/fb.h | 5 ++- 4 files changed, 23 insertions(+), 64 deletions(-) diff --git a/drivers/video/fbdev/core/fbcmap.c b/drivers/video/fbdev/core/fbcmap.c index 68a113594808..aac710b2f95f 100644 --- a/drivers/video/fbdev/core/fbcmap.c +++ b/drivers/video/fbdev/core/fbcmap.c @@ -283,11 +283,7 @@ int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info) goto out; } umap.start = cmap->start; - if (!lock_fb_info(info)) { - rc = -ENODEV; - goto out; - } - + lock_fb_info(info); rc = fb_set_cmap(&umap, info); unlock_fb_info(info); out: diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index 95af6bd783e8..35443add7f7e 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -2360,8 +2360,7 @@ static void fbcon_generic_blank(struct vc_data *vc, struct fb_info *info, } - if (!lock_fb_info(info)) - return; + lock_fb_info(info); event.info = info; event.data = ␣ fb_notifier_call_chain(FB_EVENT_CONBLANK, &event); diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index ae2db31eeba7..1987aba4f5a2 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -80,17 +80,6 @@ static void put_fb_info(struct fb_info *fb_info) fb_info->fbops->fb_destroy(fb_info); } -int lock_fb_info(struct fb_info *info) -{ - mutex_lock(&info->lock); - if (!info->fbops) { - mutex_unlock(&info->lock); - return 0; - } - return 1; -} -EXPORT_SYMBOL(lock_fb_info); - /* * Helpers */ @@ -1121,8 +1110,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, switch (cmd) { case FBIOGET_VSCREENINFO: - if (!lock_fb_info(info)) - return -ENODEV; + lock_fb_info(info); var = info->var; unlock_fb_info(info); @@ -1132,10 +1120,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, if (copy_from_user(&var, argp, sizeof(var))) return -EFAULT; console_lock(); - if (!lock_fb_info(info)) { - console_unlock(); - return -ENODEV; - } + lock_fb_info(info); info->flags |= FBINFO_MISC_USEREVENT; ret = fb_set_var(info, &var); info->flags &= ~FBINFO_MISC_USEREVENT; @@ -1145,8 +1130,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, ret = -EFAULT; break; case FBIOGET_FSCREENINFO: - if (!lock_fb_info(info)) - return -ENODEV; + lock_fb_info(info); fix = info->fix; if (info->flags & FBINFO_HIDE_SMEM_START) fix.smem_start = 0; @@ -1162,8 +1146,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, case FBIOGETCMAP: if (copy_from_user(&cmap, argp, sizeof(cmap))) return -EFAULT; - if (!lock_fb_info(info)) - return -ENODEV; + lock_fb_info(info); cmap_from = info->cmap; unlock_fb_info(info); ret = fb_cmap_to_user(&cmap_from, &cmap); @@ -1172,10 +1155,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, if (copy_from_user(&var, argp, sizeof(var))) return -EFAULT; console_lock(); - if (!lock_fb_info(info)) { - console_unlock(); - return -ENODEV; - } + lock_fb_info(info); ret = fb_pan_display(info, &var); unlock_fb_info(info); console_unlock(); @@ -1192,8 +1172,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, return -EINVAL; con2fb.framebuffer = -1; event.data = &con2fb; - if (!lock_fb_info(info)) - return -ENODEV; + lock_fb_info(info); event.info = info; fb_notifier_call_chain(FB_EVENT_GET_CONSOLE_MAP, &event); unlock_fb_info(info); @@ -1214,10 +1193,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, } event.data = &con2fb; console_lock(); - if (!lock_fb_info(info)) { - console_unlock(); - return -ENODEV; - } + lock_fb_info(info); event.info = info; ret = fb_notifier_call_chain(FB_EVENT_SET_CONSOLE_MAP, &event); unlock_fb_info(info); @@ -1225,10 +1201,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, break; case FBIOBLANK: console_lock(); - if (!lock_fb_info(info)) { - console_unlock(); - return -ENODEV; - } + lock_fb_info(info); info->flags |= FBINFO_MISC_USEREVENT; ret = fb_blank(info, arg); info->flags &= ~FBINFO_MISC_USEREVENT; @@ -1236,8 +1209,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, console_unlock(); break; default: - if (!lock_fb_info(info)) - return -ENODEV; + lock_fb_info(info); fb = info->fbops; if (fb->fb_ioctl) ret = fb->fb_ioctl(info, cmd, arg); @@ -1357,8 +1329,7 @@ static int fb_get_fscreeninfo(struct fb_info *info, unsigned int cmd, { struct fb_fix_screeninfo fix; - if (!lock_fb_info(info)) - return -ENODEV; + lock_fb_info(info); fix = info->fix; if (info->flags & FBINFO_HIDE_SMEM_START) fix.smem_start = 0; @@ -1418,8 +1389,6 @@ fb_mmap(struct file *file, struct vm_area_struct * vma) if (!info) return -ENODEV; fb = info->fbops; - if (!fb) - return -ENODEV; mutex_lock(&info->mm_lock); if (fb->fb_mmap) { int res; @@ -1483,7 +1452,7 @@ __releases(&info->lock) if (IS_ERR(info)) return PTR_ERR(info); - mutex_lock(&info->lock); + lock_fb_info(info); if (!try_module_get(info->fbops->owner)) { res = -ENODEV; goto out; @@ -1499,7 +1468,7 @@ __releases(&info->lock) fb_deferred_io_open(info, inode, file); #endif out: - mutex_unlock(&info->lock); + unlock_fb_info(info); if (res) put_fb_info(info); return res; @@ -1512,11 +1481,11 @@ __releases(&info->lock) { struct fb_info * const info = file->private_data; - mutex_lock(&info->lock); + lock_fb_info(info); if (info->fbops->fb_release) info->fbops->fb_release(info,1); module_put(info->fbops->owner); - mutex_unlock(&info->lock); + unlock_fb_info(info); put_fb_info(info); return 0; } @@ -1726,14 +1695,10 @@ static int do_register_framebuffer(struct fb_info *fb_info) console_lock(); else atomic_inc(&ignore_console_lock_warning); - if (!lock_fb_info(fb_info)) { - ret = -ENODEV; - goto unlock_console; - } - + lock_fb_info(fb_info); ret = fbcon_fb_registered(fb_info); unlock_fb_info(fb_info); -unlock_console: + if (!lockless_register_fb) console_unlock(); else @@ -1751,11 +1716,7 @@ static int unbind_console(struct fb_info *fb_info) return -EINVAL; console_lock(); - if (!lock_fb_info(fb_info)) { - console_unlock(); - return -ENODEV; - } - + lock_fb_info(fb_info); event.info = fb_info; ret = fb_notifier_call_chain(FB_EVENT_FB_UNBIND, &event); unlock_fb_info(fb_info); diff --git a/include/linux/fb.h b/include/linux/fb.h index 701abaf79c87..fd60207c0685 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -656,7 +656,10 @@ extern struct class *fb_class; for (i = 0; i < FB_MAX; i++) \ if (!registered_fb[i]) {} else -extern int lock_fb_info(struct fb_info *info); +static inline void lock_fb_info(struct fb_info *info) +{ + mutex_lock(&info->lock); +} static inline void unlock_fb_info(struct fb_info *info) { -- 2.20.1 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Date: Mon, 20 May 2019 08:21:59 +0000 Subject: [PATCH 16/33] fbdev: lock_fb_info cannot fail Message-Id: <20190520082216.26273-17-daniel.vetter@ffwll.ch> List-Id: References: <20190520082216.26273-1-daniel.vetter@ffwll.ch> In-Reply-To: <20190520082216.26273-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: DRI Development Cc: Intel Graphics Development , LKML , Daniel Vetter , Daniel Vetter , Bartlomiej Zolnierkiewicz , Hans de Goede , Yisheng Xie , Sergey Senozhatsky , =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= , Peter Rosin , =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= , Mikulas Patocka , "Gustavo A. R. Silva" , linux-fbdev@vger.kernel.org Ever since commit c47747fde931c02455683bd00ea43eaa62f35b0e Author: Linus Torvalds Date: Wed May 11 14:58:34 2011 -0700 fbmem: make read/write/ioctl use the frame buffer at open time fbdev has gained proper refcounting for the fbinfo attached to any open files, which means that the backing driver (stored in fb_info->fbops) cannot untimely disappear anymore. The only thing that can happen is that the entire device just outright disappears and gets unregistered, but file_fb_info does check for that. Except that it's racy - it only checks once at the start of a file_ops, there's no guarantee that the underlying fbdev won't untimely disappear. Aside: A proper way to fix that race is probably to replicate the srcu trickery we've rolled out in drm. But given that this race has existed since forever it's probably not one we need to fix right away. do_unregister_framebuffer also nowhere clears fb_info->fbops, hence the check in lock_fb_info can't possible catch a disappearing fbdev later on. Long story short: Ever since the above commit the fb_info->fbops checks have essentially become dead code. Remove this all. Aside from the file_ops callbacks, and stuff called from there there's only register/unregister code left. If that goes wrong a driver managed to register/unregister a device instance twice or in the wrong order. That's just a driver bug. v2: - fb_mmap had an open-coded version of the fbinfo->fops check, because it doesn't need the fbinfo->lock. Delete that too. - Use the wrapper function in fb_open/release now, since no difference anymore. Signed-off-by: Daniel Vetter Cc: Bartlomiej Zolnierkiewicz Cc: Daniel Vetter Cc: Hans de Goede Cc: Yisheng Xie Cc: Sergey Senozhatsky Cc: "Noralf Trønnes" Cc: Peter Rosin Cc: "Michał Mirosław" Cc: Mikulas Patocka Cc: "Gustavo A. R. Silva" Cc: linux-fbdev@vger.kernel.org --- drivers/video/fbdev/core/fbcmap.c | 6 +-- drivers/video/fbdev/core/fbcon.c | 3 +- drivers/video/fbdev/core/fbmem.c | 73 +++++++------------------------ include/linux/fb.h | 5 ++- 4 files changed, 23 insertions(+), 64 deletions(-) diff --git a/drivers/video/fbdev/core/fbcmap.c b/drivers/video/fbdev/core/fbcmap.c index 68a113594808..aac710b2f95f 100644 --- a/drivers/video/fbdev/core/fbcmap.c +++ b/drivers/video/fbdev/core/fbcmap.c @@ -283,11 +283,7 @@ int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info) goto out; } umap.start = cmap->start; - if (!lock_fb_info(info)) { - rc = -ENODEV; - goto out; - } - + lock_fb_info(info); rc = fb_set_cmap(&umap, info); unlock_fb_info(info); out: diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index 95af6bd783e8..35443add7f7e 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -2360,8 +2360,7 @@ static void fbcon_generic_blank(struct vc_data *vc, struct fb_info *info, } - if (!lock_fb_info(info)) - return; + lock_fb_info(info); event.info = info; event.data = ␣ fb_notifier_call_chain(FB_EVENT_CONBLANK, &event); diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index ae2db31eeba7..1987aba4f5a2 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -80,17 +80,6 @@ static void put_fb_info(struct fb_info *fb_info) fb_info->fbops->fb_destroy(fb_info); } -int lock_fb_info(struct fb_info *info) -{ - mutex_lock(&info->lock); - if (!info->fbops) { - mutex_unlock(&info->lock); - return 0; - } - return 1; -} -EXPORT_SYMBOL(lock_fb_info); - /* * Helpers */ @@ -1121,8 +1110,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, switch (cmd) { case FBIOGET_VSCREENINFO: - if (!lock_fb_info(info)) - return -ENODEV; + lock_fb_info(info); var = info->var; unlock_fb_info(info); @@ -1132,10 +1120,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, if (copy_from_user(&var, argp, sizeof(var))) return -EFAULT; console_lock(); - if (!lock_fb_info(info)) { - console_unlock(); - return -ENODEV; - } + lock_fb_info(info); info->flags |= FBINFO_MISC_USEREVENT; ret = fb_set_var(info, &var); info->flags &= ~FBINFO_MISC_USEREVENT; @@ -1145,8 +1130,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, ret = -EFAULT; break; case FBIOGET_FSCREENINFO: - if (!lock_fb_info(info)) - return -ENODEV; + lock_fb_info(info); fix = info->fix; if (info->flags & FBINFO_HIDE_SMEM_START) fix.smem_start = 0; @@ -1162,8 +1146,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, case FBIOGETCMAP: if (copy_from_user(&cmap, argp, sizeof(cmap))) return -EFAULT; - if (!lock_fb_info(info)) - return -ENODEV; + lock_fb_info(info); cmap_from = info->cmap; unlock_fb_info(info); ret = fb_cmap_to_user(&cmap_from, &cmap); @@ -1172,10 +1155,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, if (copy_from_user(&var, argp, sizeof(var))) return -EFAULT; console_lock(); - if (!lock_fb_info(info)) { - console_unlock(); - return -ENODEV; - } + lock_fb_info(info); ret = fb_pan_display(info, &var); unlock_fb_info(info); console_unlock(); @@ -1192,8 +1172,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, return -EINVAL; con2fb.framebuffer = -1; event.data = &con2fb; - if (!lock_fb_info(info)) - return -ENODEV; + lock_fb_info(info); event.info = info; fb_notifier_call_chain(FB_EVENT_GET_CONSOLE_MAP, &event); unlock_fb_info(info); @@ -1214,10 +1193,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, } event.data = &con2fb; console_lock(); - if (!lock_fb_info(info)) { - console_unlock(); - return -ENODEV; - } + lock_fb_info(info); event.info = info; ret = fb_notifier_call_chain(FB_EVENT_SET_CONSOLE_MAP, &event); unlock_fb_info(info); @@ -1225,10 +1201,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, break; case FBIOBLANK: console_lock(); - if (!lock_fb_info(info)) { - console_unlock(); - return -ENODEV; - } + lock_fb_info(info); info->flags |= FBINFO_MISC_USEREVENT; ret = fb_blank(info, arg); info->flags &= ~FBINFO_MISC_USEREVENT; @@ -1236,8 +1209,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, console_unlock(); break; default: - if (!lock_fb_info(info)) - return -ENODEV; + lock_fb_info(info); fb = info->fbops; if (fb->fb_ioctl) ret = fb->fb_ioctl(info, cmd, arg); @@ -1357,8 +1329,7 @@ static int fb_get_fscreeninfo(struct fb_info *info, unsigned int cmd, { struct fb_fix_screeninfo fix; - if (!lock_fb_info(info)) - return -ENODEV; + lock_fb_info(info); fix = info->fix; if (info->flags & FBINFO_HIDE_SMEM_START) fix.smem_start = 0; @@ -1418,8 +1389,6 @@ fb_mmap(struct file *file, struct vm_area_struct * vma) if (!info) return -ENODEV; fb = info->fbops; - if (!fb) - return -ENODEV; mutex_lock(&info->mm_lock); if (fb->fb_mmap) { int res; @@ -1483,7 +1452,7 @@ __releases(&info->lock) if (IS_ERR(info)) return PTR_ERR(info); - mutex_lock(&info->lock); + lock_fb_info(info); if (!try_module_get(info->fbops->owner)) { res = -ENODEV; goto out; @@ -1499,7 +1468,7 @@ __releases(&info->lock) fb_deferred_io_open(info, inode, file); #endif out: - mutex_unlock(&info->lock); + unlock_fb_info(info); if (res) put_fb_info(info); return res; @@ -1512,11 +1481,11 @@ __releases(&info->lock) { struct fb_info * const info = file->private_data; - mutex_lock(&info->lock); + lock_fb_info(info); if (info->fbops->fb_release) info->fbops->fb_release(info,1); module_put(info->fbops->owner); - mutex_unlock(&info->lock); + unlock_fb_info(info); put_fb_info(info); return 0; } @@ -1726,14 +1695,10 @@ static int do_register_framebuffer(struct fb_info *fb_info) console_lock(); else atomic_inc(&ignore_console_lock_warning); - if (!lock_fb_info(fb_info)) { - ret = -ENODEV; - goto unlock_console; - } - + lock_fb_info(fb_info); ret = fbcon_fb_registered(fb_info); unlock_fb_info(fb_info); -unlock_console: + if (!lockless_register_fb) console_unlock(); else @@ -1751,11 +1716,7 @@ static int unbind_console(struct fb_info *fb_info) return -EINVAL; console_lock(); - if (!lock_fb_info(fb_info)) { - console_unlock(); - return -ENODEV; - } - + lock_fb_info(fb_info); event.info = fb_info; ret = fb_notifier_call_chain(FB_EVENT_FB_UNBIND, &event); unlock_fb_info(fb_info); diff --git a/include/linux/fb.h b/include/linux/fb.h index 701abaf79c87..fd60207c0685 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -656,7 +656,10 @@ extern struct class *fb_class; for (i = 0; i < FB_MAX; i++) \ if (!registered_fb[i]) {} else -extern int lock_fb_info(struct fb_info *info); +static inline void lock_fb_info(struct fb_info *info) +{ + mutex_lock(&info->lock); +} static inline void unlock_fb_info(struct fb_info *info) { -- 2.20.1