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fbcon: Introduce wrapper for console->fb_info lookup

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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: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-4-daniel.vetter@ffwll.ch
This commit is contained in:
Daniel Vetter 2022-04-05 23:03:21 +02:00
parent 6893331363
commit 409d6c95f9
1 changed files with 44 additions and 32 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

76
drivers/video/fbdev/core/fbcon.c
View file

@ -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[MAX_NR_CONSOLES];
static signed char con2fb_map_boot[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; static int logo_lines;
/* logo_shown is an index to vc_cons when >= 0; otherwise follows FBCON_LOGO /* logo_shown is an index to vc_cons when >= 0; otherwise follows FBCON_LOGO
enums. */ enums. */
@ -199,7 +211,7 @@ static void fbcon_rotate(struct fb_info *info, u32 rotate)
if (!ops || ops->currcon == -1) if (!ops || ops->currcon == -1)
return; return;
fb_info = registered_fb[con2fb_map[ops->currcon]]; fb_info = fbcon_info_from_console(ops->currcon);
if (info == fb_info) { if (info == fb_info) {
struct fbcon_display *p = &fb_display[ops->currcon]; 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++) { for (i = first_fb_vc; i <= last_fb_vc; i++) {
vc = vc_cons[i].d; vc = vc_cons[i].d;
if (!vc || vc->vc_mode != KD_TEXT || if (!vc || vc->vc_mode != KD_TEXT ||
registered_fb[con2fb_map[i]] != info) fbcon_info_from_console(i) != info)
continue; continue;
p = &fb_display[vc->vc_num]; p = &fb_display[vc->vc_num];
@ -356,7 +368,7 @@ static void fb_flashcursor(struct work_struct *work)
vc = vc_cons[ops->currcon].d; vc = vc_cons[ops->currcon].d;
if (!vc || !con_is_visible(vc) || 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) { vc->vc_deccm != 1) {
console_unlock(); console_unlock();
return; return;
@ -791,7 +803,7 @@ static void con2fb_init_display(struct vc_data *vc, struct fb_info *info,
if (show_logo) { if (show_logo) {
struct vc_data *fg_vc = vc_cons[fg_console].d; struct vc_data *fg_vc = vc_cons[fg_console].d;
struct fb_info *fg_info = 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, fbcon_prepare_logo(fg_vc, fg_info, fg_vc->vc_cols,
fg_vc->vc_rows, 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) if (con2fb_map[vc->vc_num] == -1)
con2fb_map[vc->vc_num] = info_idx; 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) if (logo_shown < 0 && console_loglevel <= CONSOLE_LOGLEVEL_QUIET)
logo_shown = FBCON_LOGO_DONTSHOW; logo_shown = FBCON_LOGO_DONTSHOW;
@ -1231,7 +1243,7 @@ finished:
static void fbcon_clear(struct vc_data *vc, int sy, int sx, int height, static void fbcon_clear(struct vc_data *vc, int sy, int sx, int height,
int width) 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_ops *ops = info->fbcon_par;
struct fbcon_display *p = &fb_display[vc->vc_num]; 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, static void fbcon_putcs(struct vc_data *vc, const unsigned short *s,
int count, int ypos, int xpos) 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_display *p = &fb_display[vc->vc_num];
struct fbcon_ops *ops = info->fbcon_par; 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) 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; struct fbcon_ops *ops = info->fbcon_par;
if (!fbcon_is_inactive(vc, info)) 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) 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; struct fbcon_ops *ops = info->fbcon_par;
int c = scr_readw((u16 *) vc->vc_pos); 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) 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_ops *ops = info->fbcon_par;
struct fbcon_display *p = &fb_display[vc->vc_num]; 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) 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_ops *ops = info->fbcon_par;
struct fbcon_display *p = &fb_display[vc->vc_num]; 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) 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_display *p = &fb_display[vc->vc_num];
struct fbcon_ops *ops = info->fbcon_par; 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) 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_ops *ops = info->fbcon_par;
struct fbcon_display *p = &fb_display[vc->vc_num]; 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) 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_display *p = &fb_display[vc->vc_num];
struct fbcon_ops *ops = info->fbcon_par; 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) 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_ops *ops = info->fbcon_par;
struct fbcon_display *p = &fb_display[vc->vc_num]; 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, 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) 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; struct fbcon_ops *ops = info->fbcon_par;
u_int b; 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, static void fbcon_bmove(struct vc_data *vc, int sy, int sx, int dy, int dx,
int height, int width) 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]; struct fbcon_display *p = &fb_display[vc->vc_num];
if (fbcon_is_inactive(vc, info)) 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, static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
enum con_scroll dir, unsigned int count) 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]; struct fbcon_display *p = &fb_display[vc->vc_num];
int scroll_partial = info->flags & FBINFO_PARTIAL_PAN_OK; 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, static int fbcon_resize(struct vc_data *vc, unsigned int width,
unsigned int height, unsigned int user) 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_ops *ops = info->fbcon_par;
struct fbcon_display *p = &fb_display[vc->vc_num]; struct fbcon_display *p = &fb_display[vc->vc_num];
struct fb_var_screeninfo var = info->var; struct fb_var_screeninfo var = info->var;
@ -2065,7 +2077,7 @@ static int fbcon_switch(struct vc_data *vc)
struct fb_var_screeninfo var; struct fb_var_screeninfo var;
int i, ret, prev_console; 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; ops = info->fbcon_par;
if (logo_shown >= 0) { if (logo_shown >= 0) {
@ -2079,7 +2091,7 @@ static int fbcon_switch(struct vc_data *vc)
prev_console = ops->currcon; prev_console = ops->currcon;
if (prev_console != -1) 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 * FIXME: If we have multiple fbdev's loaded, we need to
* update all info->currcon. Perhaps, we can place this * 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) 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; struct fbcon_ops *ops = info->fbcon_par;
if (mode_switch) { 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) 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; struct fbcon_ops *ops = info->fbcon_par;
ops->save_graphics = ops->graphics; 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) 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; struct fbcon_ops *ops = info->fbcon_par;
ops->graphics = ops->save_graphics; 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, static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount,
const u8 * data, int userfont) 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_ops *ops = info->fbcon_par;
struct fbcon_display *p = &fb_display[vc->vc_num]; struct fbcon_display *p = &fb_display[vc->vc_num];
int resize; 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, static int fbcon_set_font(struct vc_data *vc, struct console_font *font,
unsigned int flags) 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; unsigned charcount = font->charcount;
int w = font->width; int w = font->width;
int h = font->height; 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) 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; const struct font_desc *f;
if (!name) 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) 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; int i, j, k, depth;
u8 val; u8 val;
@ -2651,7 +2663,7 @@ static void fbcon_modechanged(struct fb_info *info)
return; return;
vc = vc_cons[ops->currcon].d; vc = vc_cons[ops->currcon].d;
if (vc->vc_mode != KD_TEXT || if (vc->vc_mode != KD_TEXT ||
registered_fb[con2fb_map[ops->currcon]] != info) fbcon_info_from_console(ops->currcon) != info)
return; return;
p = &fb_display[vc->vc_num]; 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++) { for (i = first_fb_vc; i <= last_fb_vc; i++) {
vc = vc_cons[i].d; vc = vc_cons[i].d;
if (!vc || vc->vc_mode != KD_TEXT || if (!vc || vc->vc_mode != KD_TEXT ||
registered_fb[con2fb_map[i]] != info) fbcon_info_from_console(i) != info)
continue; continue;
if (con_is_visible(vc)) { 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; vc = vc_cons[ops->currcon].d;
if (vc->vc_mode != KD_TEXT || if (vc->vc_mode != KD_TEXT ||
registered_fb[con2fb_map[ops->currcon]] != info) fbcon_info_from_console(ops->currcon) != info)
return; return;
if (con_is_visible(vc)) { if (con_is_visible(vc)) {
@ -2974,7 +2986,7 @@ void fbcon_new_modelist(struct fb_info *info)
const struct fb_videomode *mode; const struct fb_videomode *mode;
for (i = first_fb_vc; i <= last_fb_vc; i++) { 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; continue;
if (!fb_display[i].mode) if (!fb_display[i].mode)
continue; continue;