From patchwork Tue Feb 8 21:08:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 12739392 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 8CAF2C433FE for ; Tue, 8 Feb 2022 22:23:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1387370AbiBHWXS (ORCPT ); Tue, 8 Feb 2022 17:23:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1386702AbiBHVIg (ORCPT ); Tue, 8 Feb 2022 16:08:36 -0500 Received: from mail-wm1-x32c.google.com (mail-wm1-x32c.google.com [IPv6:2a00:1450:4864:20::32c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65A4AC0612BF for ; Tue, 8 Feb 2022 13:08:35 -0800 (PST) Received: by mail-wm1-x32c.google.com with SMTP id k3-20020a1ca103000000b0037bdea84f9cso176894wme.1 for ; Tue, 08 Feb 2022 13:08:35 -0800 (PST) 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=a5WrS/1rmXvD/BYbGf8gVLMNVbqD+GkBVWeKUPnYEUE=; b=W8SZ9ZT9lnqf674qYwX61QIIXfYPpz5TT8FNFquYqMWF60Zr1NxVSo67LFUIumhY/b g4X3DWnYQ4E9O0TT9I27jrKoBmg4rpZuW34qAkgkfckRl0rxiOId6Jms4FaL+TttstLl RZw/gE3MZ7mAZ0AStwQU91DCKbDEAy83Zt1DU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=a5WrS/1rmXvD/BYbGf8gVLMNVbqD+GkBVWeKUPnYEUE=; b=AdKXU5dVxPpd9lMCE7lsxsqZ3AtsloO5rHidMLEnjZvK5DfAEfCz+gL6rc/kGSInyJ 3uSxJ9BjJnmgMQa37CrtNkg/3e6A9P+LM1j+ZCzef/tUCOaVqWpCVHTxwYB1e7YSitql EEa55lknCRz3eN7+0Sk5wcBfUnhkkdRY59kOG7qebUgOSP2//HbtVrA9O0Lv7KKcA28v gK/NRDbtnvkydQJfDdOap8gKQQwJnEz4KB0lqXPnDhukp3Ajiit1l79MLX3krrZlnodU ZAKO/YqNJe2B+wU7qkHzkimUg2V6eQbtijULKlnW2NCNIScuzk2LldKajkrSZYkgzrWA cmQQ== X-Gm-Message-State: AOAM530ce190p3saYx5kIZqHWquigb5fyGxVFW9u7WOVynLcz0Lt0oiG 6CEaMbv9FPhdpW6gcVRnY8Fwsw== X-Google-Smtp-Source: ABdhPJymquC64RJAFkzllw/eFz8WLOUKu7ZMOr++7kAYlKbVxvjPxIJXICIuvaEML/N2TifrI9Fp2w== X-Received: by 2002:a05:600c:4f85:: with SMTP id n5mr2579212wmq.64.1644354513896; Tue, 08 Feb 2022 13:08:33 -0800 (PST) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id o14sm3033561wmr.3.2022.02.08.13.08.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Feb 2022 13:08:32 -0800 (PST) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , linux-fbdev@vger.kernel.org, LKML , Daniel Vetter , Sam Ravnborg , Daniel Vetter , Helge Deller , Daniel Vetter , Greg Kroah-Hartman , Tetsuo Handa , Du Cheng , Claudio Suarez , Thomas Zimmermann Subject: [PATCH v2 03/19] fbcon: Introduce wrapper for console->fb_info lookup Date: Tue, 8 Feb 2022 22:08:08 +0100 Message-Id: <20220208210824.2238981-4-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220208210824.2238981-1-daniel.vetter@ffwll.ch> References: <20220208210824.2238981-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Half of it is protected by console_lock, but the other half is a lot more awkward: Registration/deregistration of fbdev are serialized, but we don't really clear out anything in con2fb_map and so there's potential for use-after free mixups. First step is to encapsulate the lookup. Acked-by: Sam Ravnborg Signed-off-by: Daniel Vetter Cc: Helge Deller Cc: Daniel Vetter Cc: Greg Kroah-Hartman Cc: Tetsuo Handa Cc: Du Cheng Cc: Claudio Suarez Cc: Thomas Zimmermann Acked-by: Thomas Zimmermann --- drivers/video/fbdev/core/fbcon.c | 76 ++++++++++++++++++-------------- 1 file changed, 44 insertions(+), 32 deletions(-) diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index e925bb608e25..b75e638cb83d 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -110,6 +110,18 @@ static struct fbcon_display fb_display[MAX_NR_CONSOLES]; static signed char con2fb_map[MAX_NR_CONSOLES]; static signed char con2fb_map_boot[MAX_NR_CONSOLES]; +static struct fb_info *fbcon_info_from_console(int console) +{ + WARN_CONSOLE_UNLOCKED(); + + /* + * Note that only con2fb_map is protected by the console lock, + * registered_fb is protected by a separate mutex. This lookup can + * therefore race. + */ + return registered_fb[con2fb_map[console]]; +} + static int logo_lines; /* logo_shown is an index to vc_cons when >= 0; otherwise follows FBCON_LOGO enums. */ @@ -199,7 +211,7 @@ static void fbcon_rotate(struct fb_info *info, u32 rotate) if (!ops || ops->currcon == -1) return; - fb_info = registered_fb[con2fb_map[ops->currcon]]; + fb_info = fbcon_info_from_console(ops->currcon); if (info == fb_info) { struct fbcon_display *p = &fb_display[ops->currcon]; @@ -226,7 +238,7 @@ static void fbcon_rotate_all(struct fb_info *info, u32 rotate) for (i = first_fb_vc; i <= last_fb_vc; i++) { vc = vc_cons[i].d; if (!vc || vc->vc_mode != KD_TEXT || - registered_fb[con2fb_map[i]] != info) + fbcon_info_from_console(i) != info) continue; p = &fb_display[vc->vc_num]; @@ -356,7 +368,7 @@ static void fb_flashcursor(struct work_struct *work) vc = vc_cons[ops->currcon].d; if (!vc || !con_is_visible(vc) || - registered_fb[con2fb_map[vc->vc_num]] != info || + fbcon_info_from_console(vc->vc_num) != info || vc->vc_deccm != 1) { console_unlock(); return; @@ -791,7 +803,7 @@ static void con2fb_init_display(struct vc_data *vc, struct fb_info *info, if (show_logo) { struct vc_data *fg_vc = vc_cons[fg_console].d; struct fb_info *fg_info = - registered_fb[con2fb_map[fg_console]]; + fbcon_info_from_console(fg_console); fbcon_prepare_logo(fg_vc, fg_info, fg_vc->vc_cols, fg_vc->vc_rows, fg_vc->vc_cols, @@ -1014,7 +1026,7 @@ static void fbcon_init(struct vc_data *vc, int init) if (con2fb_map[vc->vc_num] == -1) con2fb_map[vc->vc_num] = info_idx; - info = registered_fb[con2fb_map[vc->vc_num]]; + info = fbcon_info_from_console(vc->vc_num); if (logo_shown < 0 && console_loglevel <= CONSOLE_LOGLEVEL_QUIET) logo_shown = FBCON_LOGO_DONTSHOW; @@ -1231,7 +1243,7 @@ static void fbcon_deinit(struct vc_data *vc) static void fbcon_clear(struct vc_data *vc, int sy, int sx, int height, int width) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_ops *ops = info->fbcon_par; struct fbcon_display *p = &fb_display[vc->vc_num]; @@ -1269,7 +1281,7 @@ static void fbcon_clear(struct vc_data *vc, int sy, int sx, int height, static void fbcon_putcs(struct vc_data *vc, const unsigned short *s, int count, int ypos, int xpos) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_display *p = &fb_display[vc->vc_num]; struct fbcon_ops *ops = info->fbcon_par; @@ -1289,7 +1301,7 @@ static void fbcon_putc(struct vc_data *vc, int c, int ypos, int xpos) static void fbcon_clear_margins(struct vc_data *vc, int bottom_only) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_ops *ops = info->fbcon_par; if (!fbcon_is_inactive(vc, info)) @@ -1298,7 +1310,7 @@ static void fbcon_clear_margins(struct vc_data *vc, int bottom_only) static void fbcon_cursor(struct vc_data *vc, int mode) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_ops *ops = info->fbcon_par; int c = scr_readw((u16 *) vc->vc_pos); @@ -1392,7 +1404,7 @@ static void fbcon_set_disp(struct fb_info *info, struct fb_var_screeninfo *var, static __inline__ void ywrap_up(struct vc_data *vc, int count) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_ops *ops = info->fbcon_par; struct fbcon_display *p = &fb_display[vc->vc_num]; @@ -1411,7 +1423,7 @@ static __inline__ void ywrap_up(struct vc_data *vc, int count) static __inline__ void ywrap_down(struct vc_data *vc, int count) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_ops *ops = info->fbcon_par; struct fbcon_display *p = &fb_display[vc->vc_num]; @@ -1430,7 +1442,7 @@ static __inline__ void ywrap_down(struct vc_data *vc, int count) static __inline__ void ypan_up(struct vc_data *vc, int count) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_display *p = &fb_display[vc->vc_num]; struct fbcon_ops *ops = info->fbcon_par; @@ -1454,7 +1466,7 @@ static __inline__ void ypan_up(struct vc_data *vc, int count) static __inline__ void ypan_up_redraw(struct vc_data *vc, int t, int count) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_ops *ops = info->fbcon_par; struct fbcon_display *p = &fb_display[vc->vc_num]; @@ -1478,7 +1490,7 @@ static __inline__ void ypan_up_redraw(struct vc_data *vc, int t, int count) static __inline__ void ypan_down(struct vc_data *vc, int count) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_display *p = &fb_display[vc->vc_num]; struct fbcon_ops *ops = info->fbcon_par; @@ -1502,7 +1514,7 @@ static __inline__ void ypan_down(struct vc_data *vc, int count) static __inline__ void ypan_down_redraw(struct vc_data *vc, int t, int count) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_ops *ops = info->fbcon_par; struct fbcon_display *p = &fb_display[vc->vc_num]; @@ -1666,7 +1678,7 @@ static void fbcon_redraw(struct vc_data *vc, struct fbcon_display *p, static void fbcon_bmove_rec(struct vc_data *vc, struct fbcon_display *p, int sy, int sx, int dy, int dx, int height, int width, u_int y_break) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_ops *ops = info->fbcon_par; u_int b; @@ -1708,7 +1720,7 @@ static void fbcon_bmove_rec(struct vc_data *vc, struct fbcon_display *p, int sy, static void fbcon_bmove(struct vc_data *vc, int sy, int sx, int dy, int dx, int height, int width) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_display *p = &fb_display[vc->vc_num]; if (fbcon_is_inactive(vc, info)) @@ -1731,7 +1743,7 @@ static void fbcon_bmove(struct vc_data *vc, int sy, int sx, int dy, int dx, static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b, enum con_scroll dir, unsigned int count) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_display *p = &fb_display[vc->vc_num]; int scroll_partial = info->flags & FBINFO_PARTIAL_PAN_OK; @@ -1996,7 +2008,7 @@ static void updatescrollmode(struct fbcon_display *p, static int fbcon_resize(struct vc_data *vc, unsigned int width, unsigned int height, unsigned int user) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_ops *ops = info->fbcon_par; struct fbcon_display *p = &fb_display[vc->vc_num]; struct fb_var_screeninfo var = info->var; @@ -2065,7 +2077,7 @@ static int fbcon_switch(struct vc_data *vc) struct fb_var_screeninfo var; int i, ret, prev_console; - info = registered_fb[con2fb_map[vc->vc_num]]; + info = fbcon_info_from_console(vc->vc_num); ops = info->fbcon_par; if (logo_shown >= 0) { @@ -2079,7 +2091,7 @@ static int fbcon_switch(struct vc_data *vc) prev_console = ops->currcon; if (prev_console != -1) - old_info = registered_fb[con2fb_map[prev_console]]; + old_info = fbcon_info_from_console(prev_console); /* * FIXME: If we have multiple fbdev's loaded, we need to * update all info->currcon. Perhaps, we can place this @@ -2202,7 +2214,7 @@ static void fbcon_generic_blank(struct vc_data *vc, struct fb_info *info, static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_ops *ops = info->fbcon_par; if (mode_switch) { @@ -2244,7 +2256,7 @@ static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch) static int fbcon_debug_enter(struct vc_data *vc) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_ops *ops = info->fbcon_par; ops->save_graphics = ops->graphics; @@ -2257,7 +2269,7 @@ static int fbcon_debug_enter(struct vc_data *vc) static int fbcon_debug_leave(struct vc_data *vc) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_ops *ops = info->fbcon_par; ops->graphics = ops->save_graphics; @@ -2393,7 +2405,7 @@ static void set_vc_hi_font(struct vc_data *vc, bool set) static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount, const u8 * data, int userfont) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); struct fbcon_ops *ops = info->fbcon_par; struct fbcon_display *p = &fb_display[vc->vc_num]; int resize; @@ -2447,7 +2459,7 @@ static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount, static int fbcon_set_font(struct vc_data *vc, struct console_font *font, unsigned int flags) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); unsigned charcount = font->charcount; int w = font->width; int h = font->height; @@ -2511,7 +2523,7 @@ static int fbcon_set_font(struct vc_data *vc, struct console_font *font, static int fbcon_set_def_font(struct vc_data *vc, struct console_font *font, char *name) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); const struct font_desc *f; if (!name) @@ -2535,7 +2547,7 @@ static struct fb_cmap palette_cmap = { static void fbcon_set_palette(struct vc_data *vc, const unsigned char *table) { - struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]]; + struct fb_info *info = fbcon_info_from_console(vc->vc_num); int i, j, k, depth; u8 val; @@ -2651,7 +2663,7 @@ static void fbcon_modechanged(struct fb_info *info) return; vc = vc_cons[ops->currcon].d; if (vc->vc_mode != KD_TEXT || - registered_fb[con2fb_map[ops->currcon]] != info) + fbcon_info_from_console(ops->currcon) != info) return; p = &fb_display[vc->vc_num]; @@ -2691,7 +2703,7 @@ static void fbcon_set_all_vcs(struct fb_info *info) for (i = first_fb_vc; i <= last_fb_vc; i++) { vc = vc_cons[i].d; if (!vc || vc->vc_mode != KD_TEXT || - registered_fb[con2fb_map[i]] != info) + fbcon_info_from_console(i) != info) continue; if (con_is_visible(vc)) { @@ -2954,7 +2966,7 @@ void fbcon_fb_blanked(struct fb_info *info, int blank) vc = vc_cons[ops->currcon].d; if (vc->vc_mode != KD_TEXT || - registered_fb[con2fb_map[ops->currcon]] != info) + fbcon_info_from_console(ops->currcon) != info) return; if (con_is_visible(vc)) { @@ -2974,7 +2986,7 @@ void fbcon_new_modelist(struct fb_info *info) const struct fb_videomode *mode; for (i = first_fb_vc; i <= last_fb_vc; i++) { - if (registered_fb[con2fb_map[i]] != info) + if (fbcon_info_from_console(i) != info) continue; if (!fb_display[i].mode) continue;