fbcon: Increase maximum font width x height to 64 x 128

By using bitmaps we actually support whatever size we would want, but
the console currently limits fonts to 64x128 (which gives 60x16 text on
4k screens), so we don't need more for now, and we can easily increase
later.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Helge Deller <deller@gmx.de>

fbcon: remove fbcon_getxy()

Again, fbcon_getxy() is the same as the default implementation since the
softscroll removal in commit 50145474f6ef (fbcon: remove soft scrollback
code). Drop that.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-43-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fbcon: remove consw::con_screen_pos()

fbcon_screen_pos() performs the same as the default implementation. The
only difference in the default implementation is that is considers both
vc->vc_origin and vc->vc_visible_origin. But given fbcon's softscroll
code was already removed in commit 50145474f6ef (fbcon: remove soft
scrollback code), both are always the same.

So remove fbcon_screen_pos() too.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-40-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: vt: make consw::con_font_default()'s name const

It's a name after all and that is not supposed to be changed. So make it
const to make this obvious.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-38-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: vt: make font of consw::con_font_set() const

Provided the font parameter of consw::con_font_set() is not supposed to
be changed, make it const.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-37-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: vt: make types around consw::con_blank() bool

Both the mode_switch parameter and the return value (a redraw needed)
are true/false. So switch them to bool, so that users won't return
-Eerrors or anything else.

And document the hook.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-36-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: vt: use enum constants for VESA blanking modes

Use the new enum for VESA constants. This improves type checking in
consw::con_blank().

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-35-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: vt: make consw::con_switch() return a bool

The non-zero (true) return value from consw::con_switch() means a redraw
is needed. So make this return type a bool explicitly instead of int.
The latter might imply that -Eerrors are expected. They are not.

And document the hook.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-31-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: vt: remove CM_* constants

There is no difference between CM_MOVE and CM_DRAW. Either of them
enables the cursor. CM_ERASE then disables cursor.

So get rid of all of them and use simple "bool enable".

Note that this propagates down to the fbcon code.

And document the hook.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-30-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: vt: sanitize consw::con_putcs() parameters

Similar to con_putc() in the previous patch:
* make the pointer to charattr a pointer to u16, and
* make x, y, and count unsigned as they are strictly non-negative.

And again, document that hook.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-27-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: vt: eliminate unneeded consw::con_putc() implementations

All these consw::con_putc() implementations do the same as
consw::con_putcs() (only for one charattr) or even call
consw::con_putcs() on their own.

Drop them, as thanks to the new con_putc() helper in the previous patch,
the console code performs this already -- exactly if consw::con_putc()
is missing (NULL).

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-25-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: vt: sanitize arguments of consw::con_clear()

In consw::con_clear():
* Height is always 1, so drop it.
* Offsets and width are always unsigned values, so re-type them as such.

This needs a new __fbcon_clear() in the fbcon code to still handle
height which might not be 1 when called internally.

Note that tests for negative count/width are left in place -- they are
taken care of in the next patches.

And document the hook.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-22-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: vt: make init parameter of consw::con_init() a bool

The 'init' parameter of consw::con_init() is true for the first call of
the hook on a particular console. So make the parameter a bool.

And document the hook.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-21-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: vt: make consw::con_debug_*() return void

The return value of con_debug_enter() and con_debug_leave() is ignored
on many fronts. So just don't propagate errors (the current
implementations return 0 anyway) and make the return type a void.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-20-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: vt: pass vc_resize_user as a parameter

It is pretty unfortunate to set vc_data::vc_resize_user in two callers
of vc_do_resize(). vc_resize_user is immediately reset there (while
remembering it). So instead of this back and forth, pass 'from_user' as
a parameter.

Notes on 'int user':
* The name changes from 'user' to 'from_user' on some places to be
consistent.
* The type is bool now as 'int user' might evoke user's uid or whatever.

Provided vc_resize() is called on many places and they need not to care
about this parameter, its prototype is kept unchanged. Instead, it is
now an inline calling a new __vc_resize() which implements the above.

This patch makes the situation much more obvious.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-8-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fbcon: make display_desc a static array in fbcon_startup()

display_desc is a pointer to a RO string. Instead, switch display_desc
to a static array as we are used to. It BTW saves unnecessary 8B on the
stack.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-3-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fbcon: always restore the old font data in fbcon_do_set_font()

Commit a5a923038d70 (fbdev: fbcon: Properly revert changes when
vc_resize() failed) started restoring old font data upon failure (of
vc_resize()). But it performs so only for user fonts. It means that the
"system"/internal fonts are not restored at all. So in result, the very
first call to fbcon_do_set_font() performs no restore at all upon
failing vc_resize().

This can be reproduced by Syzkaller to crash the system on the next
invocation of font_get(). It's rather hard to hit the allocation failure
in vc_resize() on the first font_set(), but not impossible. Esp. if
fault injection is used to aid the execution/failure. It was
demonstrated by Sirius:
BUG: unable to handle page fault for address: fffffffffffffff8
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD cb7b067 P4D cb7b067 PUD cb7d067 PMD 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8007 Comm: poc Not tainted 6.7.0-g9d1694dc91ce #20
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:fbcon_get_font+0x229/0x800 drivers/video/fbdev/core/fbcon.c:2286
Call Trace:
<TASK>
con_font_get drivers/tty/vt/vt.c:4558 [inline]
con_font_op+0x1fc/0xf20 drivers/tty/vt/vt.c:4673
vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]
vt_ioctl+0x632/0x2ec0 drivers/tty/vt/vt_ioctl.c:752
tty_ioctl+0x6f8/0x1570 drivers/tty/tty_io.c:2803
vfs_ioctl fs/ioctl.c:51 [inline]
...

So restore the font data in any case, not only for user fonts. Note the
later 'if' is now protected by 'old_userfont' and not 'old_data' as the
latter is always set now. (And it is supposed to be non-NULL. Otherwise
we would see the bug above again.)

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Fixes: a5a923038d70 ("fbdev: fbcon: Properly revert changes when vc_resize() failed")
Reported-and-tested-by: Ubisectech Sirius <bugreport@ubisectech.com>
Cc: Ubisectech Sirius <bugreport@ubisectech.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20240208114411.14604-1-jirislaby@kernel.org

fbcon: Fix incorrect printed function name in fbcon_prepare_logo()

If the boot logo does not fit, a message is printed, including a wrong
function name prefix. Instead of correcting the function name (or using
__func__), just use "fbcon", like is done in several other messages.

While at it, modernize the call by switching to pr_info().

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Helge Deller <deller@gmx.de>

fbdev/core: Move logo functions into separate source file

Move the fbdev function for displaying boot-up logos into their
own file fb_logo.c. Only build fb_logo.c if CONFIG_LOGO has been
selected. No functional changes.

v2:
* include fb_internal.h (kernel test robot)
* simplify option-parsing ifdefs
* build fb_logo.o iff CONFIG_LOGO has been set

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230907085408.9354-6-tzimmermann@suse.de

fbcon: Make fbcon_registered_fb and fbcon_num_registered_fb static

fbcon_registered_fb and fbcon_num_registered_fb is not referred outside
drivers/video/fbdev/core/fbcon.c, so make them static.

Signed-off-by: GUO Zihua <guozihua@huawei.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803020939.491-1-guozihua@huawei.com

Revert "fbcon: Use kzalloc() in fbcon_prepare_logo()"

This reverts commit a6a00d7e8ffd78d1cdb7a43f1278f081038c638f.

This commit is redundant, as the root cause that resulted in a false
positive was fixed by commit 27f644dc5a77f8d9 ("x86: kmsan: use C
versions of memset16/memset32/memset64").

Closes: https://lore.kernel.org/r/CAMuHMdUH4CU9EfoirSxjivg08FDimtstn7hizemzyQzYeq6b6g@mail.gmail.com/
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/bd8b71bb13af21cc48af40349db440f794336d3a.1690535849.git.geert+renesas@glider.be

fbdev/core: Rework fb init code

Init the class "graphics" before the rest of fbdev. Later steps, such
as the sysfs code, depend on the class. Also arrange the module's exit
code in reverse order.

Unexport the global variable fb_class, which is only shared internally
within the fbdev core module.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230613110953.24176-38-tzimmermann@suse.de

fbcon: remove unused display (p) from fbcon_redraw()

The parameter is unused.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Helge Deller <deller@gmx.de>

fbdev: Include <linux/fb.h> instead of <asm/fb.h>

Replace include statements for <asm/fb.h> with <linux/fb.h>. Fixes
the coding style: if a header is available in asm/ and linux/, it
is preferable to include the header from linux/. This only affects
a few source files, most of which already include <linux/fb.h>.

Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230512102444.5438-6-tzimmermann@suse.de

fbcon: set_con2fb_map needs to set con2fb_map!

I got really badly confused in d443d9386472 ("fbcon: move more common
code into fb_open()") because we set the con2fb_map before the failure
points, which didn't look good.

But in trying to fix that I moved the assignment into the wrong path -
we need to do it for _all_ vc we take over, not just the first one
(which additionally requires the call to con2fb_acquire_newinfo).

I've figured this out because of a KASAN bug report, where the
fbcon_registered_fb and fbcon_display arrays went out of sync in
fbcon_mode_deleted() because the con2fb_map pointed at the old
fb_info, but the modes and everything was updated for the new one.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Helge Deller <deller@gmx.de>
Tested-by: Xingyuan Mo <hdthky0@gmail.com>
Fixes: d443d9386472 ("fbcon: move more common code into fb_open()")
Reported-by: Xingyuan Mo <hdthky0@gmail.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Xingyuan Mo <hdthky0@gmail.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v5.19+

fbcon: Fix error paths in set_con2fb_map

This is a regressoin introduced in b07db3958485 ("fbcon: Ditch error
handling for con2fb_release_oldinfo"). I failed to realize what the if
(!err) checks. The mentioned commit was dropping the
con2fb_release_oldinfo() return value but the if (!err) was also
checking whether the con2fb_acquire_newinfo() function call above
failed or not.

Fix this with an early return statement.

Note that there's still a difference compared to the orginal state of
the code, the below lines are now also skipped on error:

if (!search_fb_in_map(info_idx))
info_idx = newidx;

These are only needed when we've actually thrown out an old fb_info
from the console mappings, which only happens later on.

Also move the fbcon_add_cursor_work() call into the same if block,
it's all protected by console_lock so doesn't matter when we set up
the blinking cursor delayed work anyway. This further simplifies the
control flow and allows us to ditch the found local variable.

v2: Clarify commit message (Javier)

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Helge Deller <deller@gmx.de>
Tested-by: Xingyuan Mo <hdthky0@gmail.com>
Fixes: b07db3958485 ("fbcon: Ditch error handling for con2fb_release_oldinfo")
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Xingyuan Mo <hdthky0@gmail.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v5.19+

VT: Bump font size limitation to 64x128 pixels

This moves 32x32 font size limitation checking down to drivers, so that
fbcon can allow large fonts.

We still keep a limitation to 64x128 pixels so as to have a simple bounded
allocation for con_font_get and in the userland kbd tool. That glyph size
will however be enough to have 128x36 characters on a "16/9 8K display".

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Link: https://lore.kernel.org/r/20230119151935.112415738@ens-lyon.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

VT: Add height parameter to con_font_get/set consw operations

The current con_font_get/set API currently hardcodes a 32-pixel-tall
limitation, which only dates from the old VGA hardware which could not
handle taller fonts than that.

This change just adds a vpitch parameter to release this
constraint. Drivers which do not support vpitch != 32 can just return
EINVAL when it is not 32, font loading tools will revert to trying 32
and succeed.

This change makes the fbcon driver consider vpitch appropriately, thus
making it able to load large fonts.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Link: https://lore.kernel.org/r/20230119151934.932642243@ens-lyon.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "fbcon: don't lose the console font across generic->chip driver switch"

This reverts commit ae1287865f5361fa138d4d3b1b6277908b54eac9.

Always free the console font when deinitializing the framebuffer
console. Subsequent framebuffer consoles will then use the default
font. Rely on userspace to load any user-configured font for these
consoles.

Commit ae1287865f53 ("fbcon: don't lose the console font across
generic->chip driver switch") was introduced to work around losing
the font during graphics-device handover. [1][2] It kept a dangling
pointer with the font data between loading the two consoles, which is
fairly adventurous hack. It also never covered cases when the other
consoles, such as VGA text mode, where involved.

The problem has meanwhile been solved in userspace. Systemd comes
with a udev rule that re-installs the configured font when a console
comes up. [3] So the kernel workaround can be removed.

This also removes one of the two special cases triggered by setting
FBINFO_MISC_FIRMWARE in an fbdev driver.

Tested during device handover from efifb and simpledrm to radeon. Udev
reloads the configured console font for the new driver's terminal.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=892340 # 1
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1074624 # 2
Link: https://cgit.freedesktop.org/systemd/systemd/tree/src/vconsole/90-vconsole.rules.in?h=v222 # 3
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221219160516.23436-3-tzimmermann@suse.de

fbcon: Remove trailing whitespaces

Fix coding style. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221219160516.23436-2-tzimmermann@suse.de

fbcon: Check font dimension limits

blit_x and blit_y are u32, so fbcon currently cannot support fonts
larger than 32x32.

The 32x32 case also needs shifting an unsigned int, to properly set bit
31, otherwise we get "UBSAN: shift-out-of-bounds in fbcon_set_font",
as reported on:

http://lore.kernel.org/all/IA1PR07MB98308653E259A6F2CE94A4AFABCE9@IA1PR07MB9830.namprd07.prod.outlook.com
Kernel Branch: 6.2.0-rc5-next-20230124
Kernel config: https://drive.google.com/file/d/1F-LszDAizEEH0ZX0HcSR06v5q8FPl2Uv/view?usp=sharing
Reproducer: https://drive.google.com/file/d/1mP1jcLBY7vWCNM60OMf-ogw-urQRjNrm/view?usp=sharing

Reported-by: Sanan Hasanov <sanan.hasanov@Knights.ucf.edu>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Fixes: 2d2699d98492 ("fbcon: font setting should check limitation of driver")
Cc: stable@vger.kernel.org
Tested-by: Miko Larsson <mikoxyzzz@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Helge Deller <deller@gmx.de>

fbdev: fbcon: release buffer when fbcon_do_set_font() failed

syzbot is reporting memory leak at fbcon_do_set_font() [1], for
commit a5a923038d70 ("fbdev: fbcon: Properly revert changes when
vc_resize() failed") missed that the buffer might be newly allocated
by fbcon_set_font().

Link: https://syzkaller.appspot.com/bug?extid=25bdb7b1703639abd498 [1]
Reported-by: syzbot <syzbot+25bdb7b1703639abd498@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+25bdb7b1703639abd498@syzkaller.appspotmail.com>
Fixes: a5a923038d70 ("fbdev: fbcon: Properly revert changes when vc_resize() failed")
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Helge Deller <deller@gmx.de>

fbcon: Use kzalloc() in fbcon_prepare_logo()

A kernel built with syzbot's config file reported that

scr_memcpyw(q, save, array3_size(logo_lines, new_cols, 2))

causes uninitialized "save" to be copied.

----------
[drm] Initialized vgem 1.0.0 20120112 for vgem on minor 0
[drm] Initialized vkms 1.0.0 20180514 for vkms on minor 1
Console: switching to colour frame buffer device 128x48
=====================================================
BUG: KMSAN: uninit-value in do_update_region+0x4b8/0xba0
do_update_region+0x4b8/0xba0
update_region+0x40d/0x840
fbcon_switch+0x3364/0x35e0
redraw_screen+0xae3/0x18a0
do_bind_con_driver+0x1cb3/0x1df0
do_take_over_console+0x11cb/0x13f0
fbcon_fb_registered+0xacc/0xfd0
register_framebuffer+0x1179/0x1320
__drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40
drm_fbdev_client_hotplug+0xbea/0xda0
drm_fbdev_generic_setup+0x65e/0x9d0
vkms_init+0x9f3/0xc76
(...snipped...)

Uninit was stored to memory at:
fbcon_prepare_logo+0x143b/0x1940
fbcon_init+0x2c1b/0x31c0
visual_init+0x3e7/0x820
do_bind_con_driver+0x14a4/0x1df0
do_take_over_console+0x11cb/0x13f0
fbcon_fb_registered+0xacc/0xfd0
register_framebuffer+0x1179/0x1320
__drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40
drm_fbdev_client_hotplug+0xbea/0xda0
drm_fbdev_generic_setup+0x65e/0x9d0
vkms_init+0x9f3/0xc76
(...snipped...)

Uninit was created at:
__kmem_cache_alloc_node+0xb69/0x1020
__kmalloc+0x379/0x680
fbcon_prepare_logo+0x704/0x1940
fbcon_init+0x2c1b/0x31c0
visual_init+0x3e7/0x820
do_bind_con_driver+0x14a4/0x1df0
do_take_over_console+0x11cb/0x13f0
fbcon_fb_registered+0xacc/0xfd0
register_framebuffer+0x1179/0x1320
__drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40
drm_fbdev_client_hotplug+0xbea/0xda0
drm_fbdev_generic_setup+0x65e/0x9d0
vkms_init+0x9f3/0xc76
(...snipped...)

CPU: 2 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc4-00356-g8f2975c2bb4c #924
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
----------

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/cad03d25-0ea0-32c4-8173-fd1895314bce@I-love.SAKURA.ne.jp

fbdev: fbcon: Properly revert changes when vc_resize() failed

fbcon_do_set_font() calls vc_resize() when font size is changed.
However, if if vc_resize() failed, current implementation doesn't
revert changes for font size, and this causes inconsistent state.

syzbot reported unable to handle page fault due to this issue [1].
syzbot's repro uses fault injection which cause failure for memory
allocation, so vc_resize() failed.

This patch fixes this issue by properly revert changes for font
related date when vc_resize() failed.

Link: https://syzkaller.appspot.com/bug?id=3443d3a1fa6d964dd7310a0cb1696d165a3e07c4 [1]
Reported-by: syzbot+a168dbeaaa7778273c1b@syzkaller.appspotmail.com
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Signed-off-by: Helge Deller <deller@gmx.de>
CC: stable@vger.kernel.org # 5.15+

fbdev: Move fbdev drivers from strlcpy to strscpy

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Helge Deller <deller@gmx.de>

tty/vt: consolemap: rename struct vc_data::vc_uni_pagedir*

As a follow-up to the commit 4173f018aae1 (tty/vt: consolemap: rename
and document struct uni_pagedir), rename also the members of struct
vc_data. I.e. pagedir -> pagedict. And while touching all the places,
remove also the unnecessary vc_ prefix.

Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220614090537.15557-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fbcon: Fix boundary checks for fbcon=vc:n1-n2 parameters

The user may use the fbcon=vc:<n1>-<n2> option to tell fbcon to take
over the given range (n1...n2) of consoles. The value for n1 and n2
needs to be a positive number and up to (MAX_NR_CONSOLES - 1).
The given values were not fully checked against those boundaries yet.

To fix the issue, convert first_fb_vc and last_fb_vc to unsigned
integers and check them against the upper boundary, and make sure that
first_fb_vc is smaller than last_fb_vc.

Cc: stable@vger.kernel.org # v4.19+
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/YpkYRMojilrtZIgM@p100

fbcon: Fix accelerated fbdev scrolling while logo is still shown

There is no need to directly skip over to the SCROLL_REDRAW case while
the logo is still shown.

When using DRM, this change has no effect because the code will reach
the SCROLL_REDRAW case immediately anyway.

But if you run an accelerated fbdev driver and have
FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION enabled, console scrolling is
slowed down by factors so that it feels as if you use a 9600 baud
terminal.

So, drop those unnecessary checks and speed up fbdev console
acceleration during bootup.

Cc: stable@vger.kernel.org # v5.10+
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/YpkYxk7wsBPx3po+@p100

fbcon: Remove obsolete reference to initmem_freed

initmem_freed was removed in v2.1.124, and the underlying issue was
fixed for good in commit 92b004d1aa9f367c ("video/logo: prevent use of
logos after they have been freed").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/b8b9147a48e233fe32e072f2085c7b413cd92a00.1654702835.git.geert+renesas@glider.be

fbcon: Use fbcon_info_from_console() in fbcon_modechange_possible()

Use the fbcon_info_from_console() wrapper which was added to kernel
v5.19 with commit 409d6c95f9c6 ("fbcon: Introduce wrapper for console->fb_info lookup").

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>

fbcon: Prevent that screen size is smaller than font size

We need to prevent that users configure a screen size which is smaller than the
currently selected font size. Otherwise rendering chars on the screen will
access memory outside the graphics memory region.

This patch adds a new function fbcon_modechange_possible() which
implements this check and which later may be extended with other checks
if necessary. The new function is called from the FBIOPUT_VSCREENINFO
ioctl handler in fbmem.c, which will return -EINVAL if userspace asked
for a too small screen size.

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org # v5.4+

fbcon: Disallow setting font bigger than screen size

Prevent that users set a font size which is bigger than the physical screen.
It's unlikely this may happen (because screens are usually much larger than the
fonts and each font char is limited to 32x32 pixels), but it may happen on
smaller screens/LCD displays.

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org # v4.14+

fbcon: replace snprintf in show functions with sysfs_emit

Use sysfs_emit instead of scnprintf or sprintf.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Yang Guang <yang.guang5@zte.com.cn>
Signed-off-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/0cb7ca73d9cd7162988a22a24cd18bbcd3d8bb27.1638156341.git.yang.guang5@zte.com.cn

fbcon: Fix delayed takeover locking

I messed up the delayed takover path in the locking conversion in
6e7da3af008b ("fbcon: Move console_lock for register/unlink/unregister").

If CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER is enabled, fbcon take-over
doesn't take place when calling fbcon_fb_registered(). Instead, is deferred
using a workqueue and its fbcon_register_existing_fbs() function calls to
fbcon_fb_registered() again for each registered fbcon fb.

This leads to the console_lock tried to be held twice, causing a deadlock.

Fix it by re-extracting the lockless function and using it in the
delayed takeover path, where we need to hold the lock already to
iterate over the list of already registered fb. Well the current code
still is broken in there (since the list is protected by a
registration_lock, which we can't take here because it nests the other
way round with console_lock), but in the future this will be a list
protected by console_lock when this is all sorted out.

While reviewing the broken commit I realized that I've left some
outdated comments about the locking behind. Fix those too.

v2: Improve commit message (Javier)

Reported-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Fixes: 6e7da3af008b ("fbcon: Move console_lock for register/unlink/unregister")
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Zheyu Ma <zheyuma97@gmail.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Helge Deller <deller@gmx.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220413082128.348186-1-daniel.vetter@ffwll.ch

fbcon: use min() to make code cleaner

Use min() in order to make code cleaner.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209084810.1561184-1-deng.changcheng@zte.com.cn

fbcon: Maintain a private array of fb_info

Accessing the one in fbmem.c without taking the right locks is a bad
idea. Instead maintain our own private copy, which is fully protected
by console_lock() (like everything else in fbcon.c). That copy is
serialized through fbcon_fb_registered/unregistered() calls.

Also this means we do not need to hold a full fb_info reference, which
is nice because doing so would mean a refcount loop between the
console and the fb_info. But it's also not nice since it means
console_lock() must be held absolutely everywhere. Well strictly
speaking we could still try to do some refcounting games again by
calling get_fb_info before we drop the console_lock. But things will
get tricky.

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-18-daniel.vetter@ffwll.ch

fbcon: untangle fbcon_exit

There's a bunch of confusions going on here:
- The deferred fbcon setup notifier should only be cleaned up from
fb_console_exit(), to be symmetric with fb_console_init()
- We also need to make sure we don't race with the work, which means
temporarily dropping the console lock (or we can deadlock)
- That also means no point in clearing deferred_takeover, we are
unloading everything anyway.
- Finally rename fbcon_exit to fbcon_release_all and move it, since
that's what's it doing when being called from consw->con_deinit
through fbcon_deinit.

To answer a question from Sam just quoting my own reply:

> We loose the call to fbcon_release_all() here [in fb_console_exit()].
> We have part of the old fbcon_exit() above, but miss the release parts.

Ah yes that's the entire point of this change. The release_all in the
fbcon exit path was only needed when fbcon was a separate module
indepedent from core fb.ko. Which means it was possible to unload fbcon
while having fbdev drivers registered.

But since we've merged them that has become impossible, so by the time the
fb.ko module can be unloaded, there's guaranteed to be no fbdev drivers
left. And hence removing them is pointless.

v2: Explain the why better (Sam)

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-17-daniel.vetter@ffwll.ch

fbcon: Move more code into fbcon_release

con2fb_release_oldinfo() has a bunch more kfree() calls than
fbcon_exit(), but since kfree() on NULL is harmless doing that in both
places should be ok. This is also a bit more symmetric now again with
fbcon_open also allocating the fbcon_ops structure.

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Claudio Suarez <cssk@net-c.es>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-16-daniel.vetter@ffwll.ch

fbcon: Move console_lock for register/unlink/unregister

Ideally console_lock becomes an implementation detail of fbcon.c and
doesn't show up anywhere in fbmem.c. We're still pretty far from that,
but at least the register/unregister code is there now.

With this the do_fb_ioctl() handler is the only code in fbmem.c still
calling console_lock().

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Zheyu Ma <zheyuma97@gmail.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-15-daniel.vetter@ffwll.ch

fbcon: Consistently protect deferred_takeover with console_lock()

This shouldn't be a problem in practice since until we've actually
taken over the console there's nothing we've registered with the
console/vt subsystem, so the exit/unbind path that check this can't
do the wrong thing. But it's confusing, so fix it by moving it a tad
later.

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-14-daniel.vetter@ffwll.ch

fbcon: use lock_fb_info in fbcon_open/release

Now we get to the real motiviation, because fbmem.c insists that
that's the right lock for these.

Ofc fbcon.c has a lot more places where it probably should call
lock_fb_info(). But looking at fbmem.c at least most of these seem to
be protected by console_lock() too, which is probably what papers over
any issues.

Note that this means we're shuffling around a bit the locking sections
for some of the console takeover and unbind paths, but not all:
- console binding/unbinding from the console layer never with
lock_fb_info
- unbind (as opposed to unlink) never bother with lock_fb_info

Also the real serialization against set_par and set_pan are still
doing by wrapping the entire ioctl code in console_lock(). So this
shuffling shouldn't be worse than what we had from a "can you trigger
races?" pov, but it's at least clearer.

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Zheyu Ma <zheyuma97@gmail.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-13-daniel.vetter@ffwll.ch

fbcon: move more common code into fb_open()

No idea why con2fb_acquire_newinfo() initializes much less than
fbcon_startup(), but so be it. From a quick look most of the
un-initialized stuff should be fairly harmless, but who knows.

Note that the error handling for the con2fb_acquire_newinfo() failure
case was very strange: Callers updated con2fb_map to the new value
before calling this function, but upon error con2fb_acquire_newinfo
reset it to the old value. Since I removed the call to fbcon_release
anyway that strange error path was sticking out like a sore thumb,
hence I removed it. Which also allows us to remove the oldidx
parameter from that function.

v2: Explain what's going on with oldidx and error paths (Sam)

v3: Drop unused variable (0day)

v4: Rebased over bisect fix in previous patch, unchagend end result.

Acked-by: Sam Ravnborg <sam@ravnborg.org> (v2)
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Du Cheng <ducheng2@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-12-daniel.vetter@ffwll.ch

fbcon: Ditch error handling for con2fb_release_oldinfo

It doesn't ever fail anymore.

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-11-daniel.vetter@ffwll.ch

fbcon: Extract fbcon_open/release helpers

There's two minor behaviour changes in here:
- in error paths we now consistently call fb_ops->fb_release
- fb_release really can't fail (fbmem.c ignores it too) and there's no
reasonable cleanup we can do anyway.

Note that everything in fbcon.c is protected by the big console_lock()
lock (especially all the global variables), so the minor changes in
ordering of setup/cleanup do not matter.

v2: Explain a bit better why this is all correct (Sam)

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Du Cheng <ducheng2@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-10-daniel.vetter@ffwll.ch

fbcon: Replace FBCON_FLAGS_INIT with a boolean

It's only one flag and slightly tidier code.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Claudio Suarez <cssk@net-c.es>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-8-daniel.vetter@ffwll.ch

fbcon: Use delayed work for cursor

Allows us to delete a bunch of hand-rolled stuff using a timer plus a
separate work). Also to simplify the code we initialize the
cursor_work completely when we allocate the fbcon_ops structure,
instead of trying to cope with console re-initialization.

The motiviation here is that fbcon code stops using the fb_info.queue,
which helps with locking issues around cleanup and all that in a later
patch.

Also note that this allows us to ditch the hand-rolled work cleanup in
fbcon_exit - we already call fbcon_del_cursor_timer, which takes care
of everything. Plus this was racy anyway.

v2:
- Only INIT_DELAYED_WORK when kzalloc succeeded (Tetsuo)
- Explain that we replace both the timer and a work with the combined
delayed_work (Javier)

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-7-daniel.vetter@ffwll.ch

fbcon: delete delayed loading code

Before

commit 6104c37094e729f3d4ce65797002112735d49cd1
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue Aug 1 17:32:07 2017 +0200

fbcon: Make fbcon a built-time depency for fbdev

it was possible to load fbcon and fbdev drivers in any order, which
means that fbcon init had to handle the case where fbdev drivers where
already registered.

This is no longer possible, hence delete that code.

Note that the exit case is a bit more complex and will be done in a
separate patch.

Since I had to audit the entire fbcon load code I also spotted a wrong
function name in a comment in fbcon_startup(), which this patch also
fixes.

v2: Explain why we also fix the comment (Sam)

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: Claudio Suarez <cssk@net-c.es>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Du Cheng <ducheng2@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-5-daniel.vetter@ffwll.ch

fbcon: Introduce wrapper for console->fb_info lookup

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

fbcon: Move fbcon_bmove(_rec) functions

Avoids two forward declarations, and more importantly, matches what
I've done in my fbcon scrolling restore patches - so I need this to
avoid a bunch of conflicts in rebasing since we ended up merging
Helge's series instead.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-3-daniel.vetter@ffwll.ch

fbcon: delete a few unneeded forward decl

I didn't bother with any code movement to fix the others, these just
got a bit in the way.

v2: Rebase on top of Helge's reverts.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org> (v1)
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-2-daniel.vetter@ffwll.ch

fbcon: Avoid 'cap' set but not used warning

Fix this kernel test robot warning:

drivers/video/fbdev/core/fbcon.c: In function 'fbcon_init':
drivers/video/fbdev/core/fbcon.c:1028:6: warning: variable 'cap' set but not used [-Wunused-but-set-variable]

The cap variable is only used when CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION
is enabled. Drop the temporary variable and use info->flags instead.

Fixes: 87ab9f6b7417 ("Revert "fbcon: Disable accelerated scrolling")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/YgFB4xqI+As196FR@p100

fbcon: Add option to enable legacy hardware acceleration

Add a config option CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION to
enable bitblt and fillrect hardware acceleration in the framebuffer
console. If disabled, such acceleration will not be used, even if it is
supported by the graphics hardware driver.

If you plan to use DRM as your main graphics output system, you should
disable this option since it will prevent compiling in code which isn't
used later on when DRM takes over.

For all other configurations, e.g. if none of your graphic cards support
DRM (yet), DRM isn't available for your architecture, or you can't be
sure that the graphic card in the target system will support DRM, you
most likely want to enable this option.

In the non-accelerated case (e.g. when DRM is used), the inlined
fb_scrollmode() function is hardcoded to return SCROLL_REDRAW and as such the
compiler is able to optimize much unneccesary code away.

In this v3 patch version I additionally changed the GETVYRES() and GETVXRES()
macros to take a pointer to the fbcon_display struct. This fixes the build when
console rotation is enabled and helps the compiler again to optimize out code.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-4-deller@gmx.de

Revert "fbcon: Disable accelerated scrolling"

This reverts commit 39aead8373b3c20bb5965c024dfb51a94e526151.

Revert the first (of 2) commits which disabled scrolling acceleration in
fbcon/fbdev. It introduced a regression for fbdev-supported graphic cards
because of the performance penalty by doing screen scrolling by software
instead of using the existing graphic card 2D hardware acceleration.

Console scrolling acceleration was disabled by dropping code which
checked at runtime the driver hardware capabilities for the
BINFO_HWACCEL_COPYAREA or FBINFO_HWACCEL_FILLRECT flags and if set, it
enabled scrollmode SCROLL_MOVE which uses hardware acceleration to move
screen contents. After dropping those checks scrollmode was hard-wired
to SCROLL_REDRAW instead, which forces all graphic cards to redraw every
character at the new screen position when scrolling.

This change effectively disabled all hardware-based scrolling acceleration for
ALL drivers, because now all kind of 2D hardware acceleration (bitblt,
fillrect) in the drivers isn't used any longer.

The original commit message mentions that only 3 DRM drivers (nouveau, omapdrm
and gma500) used hardware acceleration in the past and thus code for checking
and using scrolling acceleration is obsolete.

This statement is NOT TRUE, because beside the DRM drivers there are around 35
other fbdev drivers which depend on fbdev/fbcon and still provide hardware
acceleration for fbdev/fbcon.

The original commit message also states that syzbot found lots of bugs in fbcon
and thus it's "often the solution to just delete code and remove features".
This is true, and the bugs - which actually affected all users of fbcon,
including DRM - were fixed, or code was dropped like e.g. the support for
software scrollback in vgacon (commit 973c096f6a85).

So to further analyze which bugs were found by syzbot, I've looked through all
patches in drivers/video which were tagged with syzbot or syzkaller back to
year 2005. The vast majority fixed the reported issues on a higher level, e.g.
when screen is to be resized, or when font size is to be changed. The few ones
which touched driver code fixed a real driver bug, e.g. by adding a check.

But NONE of those patches touched code of either the SCROLL_MOVE or the
SCROLL_REDRAW case.

That means, there was no real reason why SCROLL_MOVE had to be ripped-out and
just SCROLL_REDRAW had to be used instead. The only reason I can imagine so far
was that SCROLL_MOVE wasn't used by DRM and as such it was assumed that it
could go away. That argument completely missed the fact that SCROLL_MOVE is
still heavily used by fbdev (non-DRM) drivers.

Some people mention that using memcpy() instead of the hardware acceleration is
pretty much the same speed. But that's not true, at least not for older graphic
cards and machines where we see speed decreases by factor 10 and more and thus
this change leads to console responsiveness way worse than before.

That's why the original commit is to be reverted. By reverting we
reintroduce hardware-based scrolling acceleration and fix the
performance regression for fbdev drivers.

There isn't any impact on DRM when reverting those patches.

Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Sven Schnelle <svens@stackframe.org>
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-3-deller@gmx.de

Revert "fbdev: Garbage collect fbdev scrolling acceleration, part 1 (from TODO list)"

This reverts commit b3ec8cdf457e5e63d396fe1346cc788cf7c1b578.

Revert the second (of 2) commits which disabled scrolling acceleration
in fbcon/fbdev. It introduced a regression for fbdev-supported graphic
cards because of the performance penalty by doing screen scrolling by
software instead of using the existing graphic card 2D hardware
acceleration.

Console scrolling acceleration was disabled by dropping code which
checked at runtime the driver hardware capabilities for the
BINFO_HWACCEL_COPYAREA or FBINFO_HWACCEL_FILLRECT flags and if set, it
enabled scrollmode SCROLL_MOVE which uses hardware acceleration to move
screen contents. After dropping those checks scrollmode was hard-wired
to SCROLL_REDRAW instead, which forces all graphic cards to redraw every
character at the new screen position when scrolling.

This change effectively disabled all hardware-based scrolling acceleration for
ALL drivers, because now all kind of 2D hardware acceleration (bitblt,
fillrect) in the drivers isn't used any longer.

The original commit message mentions that only 3 DRM drivers (nouveau, omapdrm
and gma500) used hardware acceleration in the past and thus code for checking
and using scrolling acceleration is obsolete.

This statement is NOT TRUE, because beside the DRM drivers there are around 35
other fbdev drivers which depend on fbdev/fbcon and still provide hardware
acceleration for fbdev/fbcon.

The original commit message also states that syzbot found lots of bugs in fbcon
and thus it's "often the solution to just delete code and remove features".
This is true, and the bugs - which actually affected all users of fbcon,
including DRM - were fixed, or code was dropped like e.g. the support for
software scrollback in vgacon (commit 973c096f6a85).

So to further analyze which bugs were found by syzbot, I've looked through all
patches in drivers/video which were tagged with syzbot or syzkaller back to
year 2005. The vast majority fixed the reported issues on a higher level, e.g.
when screen is to be resized, or when font size is to be changed. The few ones
which touched driver code fixed a real driver bug, e.g. by adding a check.

But NONE of those patches touched code of either the SCROLL_MOVE or the
SCROLL_REDRAW case.

That means, there was no real reason why SCROLL_MOVE had to be ripped-out and
just SCROLL_REDRAW had to be used instead. The only reason I can imagine so far
was that SCROLL_MOVE wasn't used by DRM and as such it was assumed that it
could go away. That argument completely missed the fact that SCROLL_MOVE is
still heavily used by fbdev (non-DRM) drivers.

Some people mention that using memcpy() instead of the hardware acceleration is
pretty much the same speed. But that's not true, at least not for older graphic
cards and machines where we see speed decreases by factor 10 and more and thus
this change leads to console responsiveness way worse than before.

That's why the original commit is to be reverted. By reverting we
reintroduce hardware-based scrolling acceleration and fix the
performance regression for fbdev drivers.

There isn't any impact on DRM when reverting those patches.

Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Sven Schnelle <svens@stackframe.org>
Cc: stable@vger.kernel.org # v5.16+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-2-deller@gmx.de

fbdev: Garbage collect fbdev scrolling acceleration, part 1 (from TODO list)

Scroll acceleration is disabled in fbcon by hard-wiring
p->scrollmode = SCROLL_REDRAW. Remove the obsolete code in fbcon.c
and fbdev/core/

Signed-off-by: Claudio Suarez <cssk@net-c.es>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/YVXTYqszZix9TxjJ@gineta.localdomain

tty: vt: always invoke vc->vc_sw->con_resize callback

syzbot is reporting OOB write at vga16fb_imageblit() [1], for
resize_screen() from ioctl(VT_RESIZE) returns 0 without checking whether
requested rows/columns fit the amount of memory reserved for the graphical
screen if current mode is KD_GRAPHICS.

----------
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/kd.h>
#include <linux/vt.h>

int main(int argc, char *argv[])
{
const int fd = open("/dev/char/4:1", O_RDWR);
struct vt_sizes vt = { 0x4100, 2 };

ioctl(fd, KDSETMODE, KD_GRAPHICS);
ioctl(fd, VT_RESIZE, &vt);
ioctl(fd, KDSETMODE, KD_TEXT);
return 0;
}
----------

Allow framebuffer drivers to return -EINVAL, by moving vc->vc_mode !=
KD_GRAPHICS check from resize_screen() to fbcon_resize().

Link: https://syzkaller.appspot.com/bug?extid=1f29e126cf461c4de3b3 [1]
Reported-by: syzbot <syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers: video: fbcon: fix NULL dereference in fbcon_cursor()

add null-check on function pointer before dereference on ops->cursor

Reported-by: syzbot+b67aaae8d3a927f68d20@syzkaller.appspotmail.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Du Cheng <ducheng2@gmail.com>
Link: https://lore.kernel.org/r/20210312081421.452405-1-ducheng2@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

video: fbcon: Fix warnings by using pr_debug() in fbcon

Replacing DPRINTK() statements with pr_debug fixes set but not used
warnings. And moves to a more standard logging setup at the same time.

v2:
- Fix indent (Joe)

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Joe Perches <joe@perches.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Peilin Ye <yepeilin.cs@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: George Kennedy <george.kennedy@oracle.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Peter Rosin <peda@axentia.se>
Link: https://patchwork.freedesktop.org/patch/msgid/20201128224114.1033617-3-sam@ravnborg.org

fbcon: Disable accelerated scrolling

So ever since syzbot discovered fbcon, we have solid proof that it's
full of bugs. And often the solution is to just delete code and remove
features, e.g. 50145474f6ef ("fbcon: remove soft scrollback code").

Now the problem is that most modern-ish drivers really only treat
fbcon as an dumb kernel console until userspace takes over, and Oops
printer for some emergencies. Looking at drm drivers and the basic
vesa/efi fbdev drivers shows that only 3 drivers support any kind of
acceleration:

- nouveau, seems to be enabled by default
- omapdrm, when a DMM remapper exists using remapper rewriting for
y/xpanning
- gma500, but that is getting deleted now for the GTT remapper trick,
and the accelerated copyarea never set the FBINFO_HWACCEL_COPYAREA
flag, so unused (and could be deleted already I think).

No other driver supportes accelerated fbcon. And fbcon is the only
user of this accel code (it's not exposed as uapi through ioctls),
which means we could garbage collect fairly enormous amounts of code
if we kill this.

Plus because syzbot only runs on virtual hardware, and none of the
drivers for that have acceleration, we'd remove a huge gap in testing.
And there's no other even remotely comprehensive testing aside from
syzbot.

This patch here just disables the acceleration code by always
redrawing when scrolling. The plan is that once this has been merged
for well over a year in released kernels, we can start to go around
and delete a lot of code.

v2:
- Drop a few more unused local variables, somehow I missed the
compiler warnings (Sam)
- Fix typo in comment (Jiri)
- add a todo entry for the cleanup (Thomas)

v3: Remove more unused variables (0day)

Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: nouveau@lists.freedesktop.org
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Peilin Ye <yepeilin.cs@gmail.com>
Cc: George Kennedy <george.kennedy@oracle.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Peter Rosin <peda@axentia.se>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201029132229.4068359-1-daniel.vetter@ffwll.ch

fbcon: Avoid using FNTCHARCNT() and hard-coded built-in font charcount

For user-provided fonts, the framebuffer layer is using a magic
negative-indexing macro, FNTCHARCNT(), to keep track of their number of
characters:

#define FNTCHARCNT(fd) (((int *)(fd))[-3])

For built-in fonts, it is using hard-coded values (256). This results in
something like the following:

map.length = (ops->p->userfont) ?
FNTCHARCNT(ops->p->fontdata) : 256;

This is unsatisfactory. In fact, there is already a `charcount` field in
our virtual console descriptor (see `struct console_font` inside `struct
vc_data`), let us use it:

map.length = vc->vc_font.charcount;

Recently we added a `charcount` field to `struct font_desc`. Use it to set
`vc->vc_font.charcount` properly. The idea is:

- We only use FNTCHARCNT() on `vc->vc_font.data` and `p->fontdata`.
Assume FNTCHARCNT() is working as intended;
- Whenever `vc->vc_font.data` is set, also set `vc->vc_font.charcount`
properly;
- We can now replace `FNTCHARCNT(vc->vc_font.data)` with
`vc->vc_font.charcount`;
- Since `p->fontdata` always point to the same font data buffer with
`vc->vc_font.data`, we can also replace `FNTCHARCNT(p->fontdata)` with
`vc->vc_font.charcount`.

In conclusion, set `vc->vc_font.charcount` properly in fbcon_startup(),
fbcon_init(), fbcon_set_disp() and fbcon_do_set_font(), then replace
FNTCHARCNT() with `vc->vc_font.charcount`. No more if-else between
negative-indexing macros and hard-coded values.

Do not include <linux/font.h> in fbcon_rotate.c and tileblit.c, since they
no longer need it.

Depends on patch "Fonts: Add charcount field to font_desc".

Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/e460a5780e54e3022661d5f09555144583b4cc59.1605169912.git.yepeilin.cs@gmail.com

console: Delete unused con_font_copy() callback implementations

Recently in commit 3c4e0dff2095 ("vt: Disable KD_FONT_OP_COPY") we
disabled the KD_FONT_OP_COPY ioctl() option. Delete all the
con_font_copy() callbacks, since we no longer use them.

Mark KD_FONT_OP_COPY as "obsolete" in include/uapi/linux/kd.h, just like
what we have done for PPPIOCDETACH in commit af8d3c7c001a ("ppp: remove
the PPPIOCDETACH ioctl").

Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/c8d28007edf50de4387e1532eb3eb736db716f73.1605169912.git.yepeilin.cs@gmail.com

fbcon: remove no-op fbcon_set_origin()

We don't need to call vc->vc_sw->con_set_origin() from set_origin()
if it is no-op.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://lore.kernel.org/r/20200915000019.3422-3-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fbcon: Fix global-out-of-bounds read in fbcon_get_font()

fbcon_get_font() is reading out-of-bounds. A malicious user may resize
`vc->vc_font.height` to a large value, causing fbcon_get_font() to
read out of `fontdata`.

fbcon_get_font() handles both built-in and user-provided fonts.
Fortunately, recently we have added FONT_EXTRA_WORDS support for built-in
fonts, so fix it by adding range checks using FNTSIZE().

This patch depends on patch "fbdev, newport_con: Move FONT_EXTRA_WORDS
macros into linux/font.h", and patch "Fonts: Support FONT_EXTRA_WORDS
macros for built-in fonts".

Cc: stable@vger.kernel.org
Reported-and-tested-by: syzbot+29d4ed7f3bdedf2aa2fd@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=08b8be45afea11888776f897895aef9ad1c3ecfd
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/b34544687a1a09d6de630659eb7a773f4953238b.1600953813.git.yepeilin.cs@gmail.com

fbcon: Remove the superfluous break

Remove the superfluous break, as there is a 'return' before it.

Fixes: bad07ff74c32 ("fbcon: smart blitter usage for scrolling")
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200918010521.69950-1-jingxiangfeng@huawei.com

fbcon: Fix user font detection test at fbcon_resize().

syzbot is reporting OOB read at fbcon_resize() [1], for
commit 39b3cffb8cf31117 ("fbcon: prevent user font height or width change
from causing potential out-of-bounds access") is by error using
registered_fb[con2fb_map[vc->vc_num]]->fbcon_par->p->userfont (which was
set to non-zero) instead of fb_display[vc->vc_num].userfont (which remains
zero for that display).

We could remove tricky userfont flag [2], for we can determine it by
comparing address of the font data and addresses of built-in font data.
But since that commit is failing to fix the original OOB read [3], this
patch keeps the change minimal in case we decide to revert altogether.

[1] https://syzkaller.appspot.com/bug?id=ebcbbb6576958a496500fee9cf7aa83ea00b5920
[2] https://syzkaller.appspot.com/text?tag=Patch&x=14030853900000
[3] https://syzkaller.appspot.com/bug?id=6fba8c186d97cf1011ab17660e633b1cc4e080c9

Reported-by: syzbot <syzbot+b38b1ef6edf0c74a8d97@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 39b3cffb8cf31117 ("fbcon: prevent user font height or width change from causing potential out-of-bounds access")
Cc: George Kennedy <george.kennedy@oracle.com>
Link: https://lore.kernel.org/r/f6e3e611-8704-1263-d163-f52c906a4f06@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fbcon: remove now unusued 'softback_lines' cursor() argument

Since the softscroll code got removed, this argument is always zero and
makes no sense any more.

Tested-by: Yuan Ming <yuanmingbuaa@gmail.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fbcon: remove soft scrollback code

This (and the VGA soft scrollback) turns out to have various nasty small
special cases that nobody really is willing to fight. The soft
scrollback code was really useful a few decades ago when you typically
used the console interactively as the main way to interact with the
machine, but that just isn't the case any more.

So it's not worth dragging along.

Tested-by: Yuan Ming <yuanmingbuaa@gmail.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

vt: make vc_data pointers const in selection.h

There are many functions declared in selection.h which only read from
struct vc_data passed as a parameter. Make all those uses const to hint
the compiler a bit.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200818085706.12163-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fbcon: prevent user font height or width change from causing potential out-of-bounds access

Add a check to fbcon_resize() to ensure that a possible change to user font
height or user font width will not allow a font data out-of-bounds access.
NOTE: must use original charcount in calculation as font charcount can
change and cannot be used to determine the font data allocated size.

Signed-off-by: George Kennedy <george.kennedy@oracle.com>
Cc: stable <stable@vger.kernel.org>
Reported-by: syzbot+38a3699c7eaf165b97a6@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/1596213192-6635-1-git-send-email-george.kennedy@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fbcon: Use array3_size() helper in scr_memcpyw()

Use array3_size() helper instead of the open-coded version in scr_memcpyw()
and scr_memsetw(). These sorts of multiplication factors need to be wrapped
in array3_size().

This issue was found with the help of Coccinelle and, audited and fixed
manually.

Addresses-KSPP-ID: https://github.com/KSPP/linux/issues/83
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200615231542.GA20470@embeddedor

drm/fb-helper: Fix vt restore

In the past we had a pile of hacks to orchestrate access between fbdev
emulation and native kms clients. We've tried to streamline this, by
always preferring the kms side above fbdev calls when a drm master
exists, because drm master controls access to the display resources.

Unfortunately this breaks existing userspace, specifically Xorg. When
exiting Xorg first restores the console to text mode using the KDSET
ioctl on the vt. This does nothing, because a drm master is still
around. Then it drops the drm master status, which again does nothing,
because logind is keeping additional drm fd open to be able to
orchestrate vt switches. In the past this is the point where fbdev was
restored, as part of the ->lastclose hook on the drm side.

Now to fix this regression we don't want to go back to letting fbdev
restore things whenever it feels like, or to the pile of hacks we've
had before. Instead try and go with a minimal exception to make the
KDSET case work again, and nothing else.

This means that if userspace does a KDSET call when switching between
graphical compositors, there will be some flickering with fbcon
showing up for a bit. But a) that's not a regression and b) userspace
can fix it by improving the vt switching dance - logind should have
all the information it needs.

While pondering all this I'm also wondering wheter we should have a
SWITCH_MASTER ioctl to allow race-free master status handover. But
that's for another day.

v2: Somehow forgot to cc all the fbdev people.

v3: Fix typo Alex spotted.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=208179
Cc: shlomo@fastmail.com
Reported-and-Tested-by: shlomo@fastmail.com
Cc: Michel Dänzer <michel@daenzer.net>
Fixes: 64914da24ea9 ("drm/fbdev-helper: don't force restores")
Cc: Noralf Trønnes <noralf@tronnes.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v5.7+
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Qiujun Huang <hqjagain@gmail.com>
Cc: Peter Rosin <peda@axentia.se>
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200624092910.3280448-1-daniel.vetter@ffwll.ch

vt: use newly defined CUR_* macros

We defined macros for all the magic constants in the previous patch. So
let us use the macro in the code now.

No functional change intended.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-usb@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Acked-by: Helge Deller <deller@gmx.de>
Link: https://lore.kernel.org/r/20200615074910.19267-26-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vc: separate state

There are two copies of some members of struct vc_data. This is because
we need to save them and restore later. Move these memebers to a
separate structure called vc_state. So now instead of members like:
vc_x, vc_y and vc_saved_x, vc_saved_y
we have
state and saved_state (of type: struct vc_state)
containing
state.x, state.y and saved_state.x, saved_state.y

This change:
* makes clear what is saved & restored
* eases save & restore by using memcpy (see save_cur and restore_cur)

Finally, we document the newly added struct vc_state using kernel-doc.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fbcon: fix null-ptr-deref in fbcon_switch

Set logo_shown to FBCON_LOGO_CANSHOW when the vc was deallocated.

syzkaller report: https://lkml.org/lkml/2020/3/27/403
general protection fault, probably for non-canonical address
0xdffffc000000006c: 0000 [#1] SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000360-0x0000000000000367]
RIP: 0010:fbcon_switch+0x28f/0x1740
drivers/video/fbdev/core/fbcon.c:2260

Call Trace:
redraw_screen+0x2a8/0x770 drivers/tty/vt/vt.c:1008
vc_do_resize+0xfe7/0x1360 drivers/tty/vt/vt.c:1295
fbcon_init+0x1221/0x1ab0 drivers/video/fbdev/core/fbcon.c:1219
visual_init+0x305/0x5c0 drivers/tty/vt/vt.c:1062
do_bind_con_driver+0x536/0x890 drivers/tty/vt/vt.c:3542
do_take_over_console+0x453/0x5b0 drivers/tty/vt/vt.c:4122
do_fbcon_takeover+0x10b/0x210 drivers/video/fbdev/core/fbcon.c:588
fbcon_fb_registered+0x26b/0x340 drivers/video/fbdev/core/fbcon.c:3259
do_register_framebuffer drivers/video/fbdev/core/fbmem.c:1664 [inline]
register_framebuffer+0x56e/0x980 drivers/video/fbdev/core/fbmem.c:1832
dlfb_usb_probe.cold+0x1743/0x1ba3 drivers/video/fbdev/udlfb.c:1735
usb_probe_interface+0x310/0x800 drivers/usb/core/driver.c:374

accessing vc_cons[logo_shown].d->vc_top causes the bug.

Reported-by: syzbot+732528bae351682f1f27@syzkaller.appspotmail.com
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200329085647.25133-1-hqjagain@gmail.com

fbcon: Adjust indentation in set_con2fb_map

Clang warns:

../drivers/video/fbdev/core/fbcon.c:915:3: warning: misleading
indentation; statement is not part of the previous 'if'
[-Wmisleading-indentation]
return err;
^
../drivers/video/fbdev/core/fbcon.c:912:2: note: previous statement is
here
if (!search_fb_in_map(info_idx))
^
1 warning generated.

This warning occurs because there is a space before the tab on this
line. This happens on several lines in this function; normalize them
so that the indentation is consistent with the Linux kernel coding
style and clang no longer warns.

This warning was introduced before the beginning of git history so no
fixes tab.

Link: https://github.com/ClangBuiltLinux/linux/issues/824
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218025337.35044-1-natechancellor@gmail.com

fbdev: fbmem: allow overriding the number of bootup logos

Probably most useful if you want no logo at all, or if you only want one
logo regardless of how many CPU cores you have.

Signed-off-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190827110854.12574-3-peda@axentia.se

fbcon: Export fbcon_update_vcs

I failed to spot this while compile-testing. Oops.

Reported-by: kbuild test robot <lkp@intel.com>
Fixes: 9e1467002630 ("fbcon: replace FB_EVENT_MODE_CHANGE/_ALL with direct calls")
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Peter Rosin <peda@axentia.se>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: linux-fbdev@vger.kernel.org
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190619081115.27921-1-daniel.vetter@ffwll.ch

fbcon: Document what I learned about fbcon locking

It's not pretty.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-32-daniel.vetter@ffwll.ch

fbcon: Call con2fb_map functions directly

These are actually fbcon ioctls which just happen to be exposed
through /dev/fb*. They completely ignore which fb_info they're called
on, and I think the userspace tool even hardcodes to /dev/fb0.

Hence just forward the entire thing to fbcon.c wholesale.

Note that this patch drops the fb_lock/unlock on the set side. Since
the ioctl can operate on any fb (as passed in through
con2fb.framebuffer) this is bogus. Also note that fbcon.c in general
never calls fb_lock on anything, so this has been badly broken
already.

With this the last user of the fbcon notifier callback is gone, and we
can garbage collect that too.

v2: add missing uaccess.h include (alpha fails to compile otherwise),
reported by kbuild.

v3: Remember to also drop the #defines (Maarten)

v4: Add the static inline to dummy functions.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Peter Rosin <peda@axentia.se>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-31-daniel.vetter@ffwll.ch

vgaswitcheroo: call fbcon_remap_all directly

While at it, clean up the interface a bit and push the console locking
into fbcon.c.

v2: Remove now outdated comment (Lukas).

v3: Forgot to add static inline to the dummy function.

Acked-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: linux-fbdev@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-30-daniel.vetter@ffwll.ch

fbcon: replace FB_EVENT_MODE_CHANGE/_ALL with direct calls

Create a new wrapper function for this, feels like there's some
refactoring room here between the two modes.

v2: backlight notifier is also interested in the mode change event,
it calls lcd->set_mode, of which there are 3 implementations. Thanks
to Maarten for spotting this. So we keep that. We can ditch the differentiation
between mode change and all mode changes (because backlight notifier
doesn't care), and we can drop the FBINFO_MISC_USEREVENT stuff too,
because that's just to prevent recursion between fbmem.c and fbcon.c.

While at it flatten the control flow a bit.

v3: Need to add a static inline to the dummy function.

v4: Add missing #include <fbcon.h> to sh_mob (Sam).

Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Peter Rosin <peda@axentia.se>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: linux-fbdev@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-29-daniel.vetter@ffwll.ch

fbdev: remove FBINFO_MISC_USEREVENT around fb_blank

With the recursion broken in the previous patch we can drop the
FBINFO_MISC_USEREVENT flag around calls to fb_blank - recursion
prevention was it's only job.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Peter Rosin <peda@axentia.se>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Rob Clark <robdclark@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-27-daniel.vetter@ffwll.ch

Revert "backlight/fbcon: Add FB_EVENT_CONBLANK"

This reverts commit 994efacdf9a087b52f71e620b58dfa526b0cf928.

The justification is that if hw blanking fails (i.e. fbops->fb_blank)
fails, then we still want to shut down the backlight. Which is exactly
_not_ what fb_blank() does and so rather inconsistent if we end up
with different behaviour between fbcon and direct fbdev usage. Given
that the entire notifier maze is getting in the way anyway I figured
it's simplest to revert this not well justified commit.

v2: Add static inline to the dummy version.

Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: linux-fbdev@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-25-daniel.vetter@ffwll.ch

fbdev: Call fbcon_get_requirement directly

Pretty simple case really.

v2: Forgot to remove a break;

v3: Add static inline to the dummy versions.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Peter Rosin <peda@axentia.se>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: linux-fbdev@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-24-daniel.vetter@ffwll.ch

fbcon: Call fbcon_mode_deleted/new_modelist directly

I'm not entirely clear on what new_modelist actually does, it seems
exclusively for a sysfs interface. Which in the end does amount to a
normal fb_set_par to check the mode, but then takes a different path
in both fbmem.c and fbcon.c.

I have no idea why these 2 paths are different, but then I also don't
really want to find out. So just do the simple conversion to a direct
function call.

v2: static inline for the dummy versions, I forgot.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Rosin <peda@axentia.se>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: linux-fbdev@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-23-daniel.vetter@ffwll.ch

fbdev: directly call fbcon_suspended/resumed

With the sh_mobile notifier removed we can just directly call the
fbcon code here.

v2: Remove now unused local variable.

v3: fixup !CONFIG_FRAMEBUFFER_CONSOLE, noticed by kbuild

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Konstantin Khorenko <khorenko@virtuozzo.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Peter Rosin <peda@axentia.se>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: linux-fbdev@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-22-daniel.vetter@ffwll.ch

fbcon: call fbcon_fb_bind directly

Also remove the error return value. That's all errors for either
driver bugs (trying to unbind something that isn't bound), or errors
of the new driver that will take over.

There's nothing the outgoing driver can do about this anyway, so
switch over to void.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Peter Rosin <peda@axentia.se>
Cc: Kees Cook <keescook@chromium.org>
Cc: Konstantin Khorenko <khorenko@virtuozzo.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: linux-fbdev@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-18-daniel.vetter@ffwll.ch

fbdev: lock_fb_info cannot fail

Ever since

commit c47747fde931c02455683bd00ea43eaa62f35b0e
Author: Linus Torvalds <torvalds@linux-foundation.org>
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 <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: "Noralf Trønnes" <noralf@tronnes.org>
Cc: Peter Rosin <peda@axentia.se>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: linux-fbdev@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-17-daniel.vetter@ffwll.ch

fbcon: call fbcon_fb_(un)registered directly

With

commit 6104c37094e729f3d4ce65797002112735d49cd1
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue Aug 1 17:32:07 2017 +0200

fbcon: Make fbcon a built-time depency for fbdev

we have a static dependency between fbcon and fbdev, and we can
replace the indirection through the notifier chain with a function
call.

v2: Sam Ravnborg noticed that mach-pxa/am200epd.c has a notifier too,
and listens to this.

...

Looking at the code it seems to wait for some fb to show up, so that
it can get the framebuffer base address from the fb_info struct. I
suspect his is some firmware fbdev. Then it uses that information to
let the real fbdev driver (metronomefb.c by the looks) get at the
framebuffer memory.

This doesn't looke like it's easy to fix (except by deleting the
entire thing, seems untouched since 2008, we might be able to get away
with that), so let's just stuff a few #ifdef into fb.h and fbmem.c and
cry over them for a bit.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Noralf Trønnes" <noralf@tronnes.org>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: Peter Rosin <peda@axentia.se>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: linux-fbdev@vger.kernel.org
Cc: Daniel Mack <daniel@zonque.org>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Konstantin Khorenko <khorenko@virtuozzo.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Steve Sakoman <sakoman@gmail.com>
Cc: Steve Sakoman <steve@sakoman.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-11-daniel.vetter@ffwll.ch

fbcon: Remove fbcon_has_exited

This is unused code since

commit 6104c37094e729f3d4ce65797002112735d49cd1
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue Aug 1 17:32:07 2017 +0200

fbcon: Make fbcon a built-time depency for fbdev

when fbcon was made a compile-time static dependency of fbdev. We
can't exit fbcon anymore without exiting fbdev first, which only works
if all fbdev drivers have unloaded already. Hence this is all dead
code.

v2: I missed that fbcon_exit is also called from con_deinit stuff, and
there fbcon_has_exited prevents double-cleanup. But we can fix that
by properly resetting con2fb_map[] to all -1, which is used everywhere
else to indicate "no fb_info allocate to this console". With that
change the double-cleanup (which resulted in a module refcount underflow,
among other things) is prevented.

Aside: con2fb_map is a signed char, so don't register more than 128 fb_info
or hilarity will ensue.

v3: CI showed me that I still didn't fully understand what's going on
here. The leaked references in con2fb_map have been used upon
rebinding the fb console in fbcon_init. It worked because fbdev
unregistering still cleaned out con2fb_map, and reset it to info_idx.
If the last fbdev driver unregistered, then it also reset info_idx,
and unregistered the fbcon driver.

Imo that's all a bit fragile, so let's keep the con2fb_map reset to
-1, and in fbcon_init pick info_idx if we're starting fresh. That
means unbinding and rebinding will cleanse the mapping, but why are
you doing that if you want to retain the mapping, so should be fine.

Also, I think info_idx == -1 is impossible in fbcon_init - we
unregister the fbcon in that case. So catch&warn about that.

v4: Drop unecessary assignment - I forgot to delete the first
assignment of info in fbcon_init.

Cc: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: "Noralf Trønnes" <noralf@tronnes.org>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: Konstantin Khorenko <khorenko@virtuozzo.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-10-daniel.vetter@ffwll.ch

fbcon: s/struct display/struct fbcon_display/

This was formerly used in fbdev drivers (not sure why, predates most
git history), but now it's entirely an fbcon internal thing. Give it a
more specific name.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Konstantin Khorenko <khorenko@virtuozzo.com>
Cc: Peter Rosin <peda@axentia.se>
Cc: Yisheng Xie <ysxie@foxmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-9-daniel.vetter@ffwll.ch

vt/fbcon: deinitialize resources in visual_init() after failed memory allocation

After memory allocation failure vc_allocate() doesn't clean up data
which has been initialized in visual_init(). In case of fbcon this
leads to divide-by-0 in fbcon_init() on next open of the same tty.

memory allocation in vc_allocate() may fail here:
1097: vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);

on next open() fbcon_init() skips vc_font.data initialization:
1088: if (!p->fontdata) {

division by zero in fbcon_init() happens here:
1149: new_cols /= vc->vc_font.width;

Additional check is needed in fbcon_deinit() to prevent
usage of uninitialized vc_screenbuf:

1251: if (vc->vc_hi_font_mask && vc->vc_screenbuf)
1252: set_vc_hi_font(vc, false);

Crash:

#6 [ffffc90001eafa60] divide_error at ffffffff81a00be4
[exception RIP: fbcon_init+463]
RIP: ffffffff814b860f RSP: ffffc90001eafb18 RFLAGS: 00010246
...
#7 [ffffc90001eafb60] visual_init at ffffffff8154c36e
#8 [ffffc90001eafb80] vc_allocate at ffffffff8154f53c
#9 [ffffc90001eafbc8] con_install at ffffffff8154f624
...

Signed-off-by: Grzegorz Halat <ghalat@redhat.com>
Reviewed-by: Oleksandr Natalenko <oleksandr@redhat.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vt/fbcon: deinitialize resources in visual_init() after failed memory allocation

After memory allocation failure vc_allocate() doesn't clean up data
which has been initialized in visual_init(). In case of fbcon this
leads to divide-by-0 in fbcon_init() on next open of the same tty.

memory allocation in vc_allocate() may fail here:
1097: vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);

on next open() fbcon_init() skips vc_font.data initialization:
1088: if (!p->fontdata) {

division by zero in fbcon_init() happens here:
1149: new_cols /= vc->vc_font.width;

Additional check is needed in fbcon_deinit() to prevent
usage of uninitialized vc_screenbuf:

1251: if (vc->vc_hi_font_mask && vc->vc_screenbuf)
1252: set_vc_hi_font(vc, false);

Crash:

#6 [ffffc90001eafa60] divide_error at ffffffff81a00be4
[exception RIP: fbcon_init+463]
RIP: ffffffff814b860f RSP: ffffc90001eafb18 RFLAGS: 00010246
...
#7 [ffffc90001eafb60] visual_init at ffffffff8154c36e
#8 [ffffc90001eafb80] vc_allocate at ffffffff8154f53c
#9 [ffffc90001eafbc8] con_install at ffffffff8154f624
...

Signed-off-by: Grzegorz Halat <ghalat@redhat.com>
Reviewed-by: Oleksandr Natalenko <oleksandr@redhat.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fbcon: Don't reset logo_shown when logo is currently shown

When the logo is currently drawn on a virtual console, and the console
loglevel is reduced to quiet, logo_shown must be left alone, so that it
the scrolling region on that virtual console is properly reset.

Fixes: 10993504d647 ("fbcon: Silence fbcon logo on 'quiet' boots")
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Marko Myllynen <myllynen@redhat.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

fbcon: Silence fbcon logo on 'quiet' boots

On text-based systems the 'quiet' boot option will show printk levels
higher than CONSOLE_LOGLEVEL_QUIET. The displaying of the Tux logo
during boot can cause some consoles to lose display data and as a result
confuse the end user.

Do not display the Tux logo on systems that are in 'quiet' boot.

v2: It helps to commit all my changes before sending them. Remove extra
bracket.
v3: buildbot error fix: fbcon can be built as part of a module so export console_printk
v4: move console_printk change to separate patch, and drop logo cleanup
v5: Only set FBCON_LOGO_DONTSHOW for console loglevel

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Marko Myllynen <myllynen@redhat.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

fbcon: use kvmalloc() for scrollback buffer

Scrollback frame buffer is rather big - 32K,
so it requires 3rd order page, so let's use kvmalloc() instead of
ordinary kmalloc() for it.

Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

fbdev: fbmem: convert CONFIG_FB_LOGO_CENTER into a cmd line option

A command line option is much more flexible than a config option and
the supporting code is small. Gets rid of #ifdefs in the code too...

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

fbdev: fbcon: Fix unregister crash when more than one framebuffer

When unregistering fbdev using unregister_framebuffer(), any bound
console will unbind automatically. This is working fine if this is the
only framebuffer, resulting in a switch to the dummy console. However if
there is a fb0 and I unregister fb1 having a bound console, I eventually
get a crash. The fastest way for me to trigger the crash is to do a
reboot, resulting in this splat:

[ 76.478825] WARNING: CPU: 0 PID: 527 at linux/kernel/workqueue.c:1442 __queue_work+0x2d4/0x41c
[ 76.478849] Modules linked in: raspberrypi_hwmon gpio_backlight backlight bcm2835_rng rng_core [last unloaded: tinydrm]
[ 76.478916] CPU: 0 PID: 527 Comm: systemd-udevd Not tainted 4.20.0-rc4+ #4
[ 76.478933] Hardware name: BCM2835
[ 76.478949] Backtrace:
[ 76.478995] [<c010d388>] (dump_backtrace) from [<c010d670>] (show_stack+0x20/0x24)
[ 76.479022] r6:00000000 r5:c0bc73be r4:00000000 r3:6fb5bf81
[ 76.479060] [<c010d650>] (show_stack) from [<c08e82f4>] (dump_stack+0x20/0x28)
[ 76.479102] [<c08e82d4>] (dump_stack) from [<c0120070>] (__warn+0xec/0x12c)
[ 76.479134] [<c011ff84>] (__warn) from [<c01201e4>] (warn_slowpath_null+0x4c/0x58)
[ 76.479165] r9:c0eb6944 r8:00000001 r7:c0e927f8 r6:c0bc73be r5:000005a2 r4:c0139e84
[ 76.479197] [<c0120198>] (warn_slowpath_null) from [<c0139e84>] (__queue_work+0x2d4/0x41c)
[ 76.479222] r6:d7666a00 r5:c0e918ee r4:dbc4e700
[ 76.479251] [<c0139bb0>] (__queue_work) from [<c013a02c>] (queue_work_on+0x60/0x88)
[ 76.479281] r10:c0496bf8 r9:00000100 r8:c0e92ae0 r7:00000001 r6:d9403700 r5:d7666a00
[ 76.479298] r4:20000113
[ 76.479348] [<c0139fcc>] (queue_work_on) from [<c0496c28>] (cursor_timer_handler+0x30/0x54)
[ 76.479374] r7:d8a8fabc r6:c0e08088 r5:d8afdc5c r4:d8a8fabc
[ 76.479413] [<c0496bf8>] (cursor_timer_handler) from [<c0178744>] (call_timer_fn+0x100/0x230)
[ 76.479435] r4:c0e9192f r3:d758a340
[ 76.479465] [<c0178644>] (call_timer_fn) from [<c0178980>] (expire_timers+0x10c/0x12c)
[ 76.479495] r10:40000000 r9:c0e9192f r8:c0e92ae0 r7:d8afdccc r6:c0e19280 r5:c0496bf8
[ 76.479513] r4:d8a8fabc
[ 76.479541] [<c0178874>] (expire_timers) from [<c0179630>] (run_timer_softirq+0xa8/0x184)
[ 76.479570] r9:00000001 r8:c0e19280 r7:00000000 r6:c0e08088 r5:c0e1a3e0 r4:c0e19280
[ 76.479603] [<c0179588>] (run_timer_softirq) from [<c0102404>] (__do_softirq+0x1ac/0x3fc)
[ 76.479632] r10:c0e91680 r9:d8afc020 r8:0000000a r7:00000100 r6:00000001 r5:00000002
[ 76.479650] r4:c0eb65ec
[ 76.479686] [<c0102258>] (__do_softirq) from [<c0124d10>] (irq_exit+0xe8/0x168)
[ 76.479716] r10:d8d1a9b0 r9:d8afc000 r8:00000001 r7:d949c000 r6:00000000 r5:c0e8b3f0
[ 76.479734] r4:00000000
[ 76.479764] [<c0124c28>] (irq_exit) from [<c016b72c>] (__handle_domain_irq+0x94/0xb0)
[ 76.479793] [<c016b698>] (__handle_domain_irq) from [<c01021dc>] (bcm2835_handle_irq+0x3c/0x48)
[ 76.479823] r8:d8afdebc r7:d8afddfc r6:ffffffff r5:c0e089f8 r4:d8afddc8 r3:d8afddc8
[ 76.479851] [<c01021a0>] (bcm2835_handle_irq) from [<c01019f0>] (__irq_svc+0x70/0x98)

The problem is in the console rebinding in fbcon_fb_unbind(). It uses the
virtual console index as the new framebuffer index to bind the console(s)
to. The correct way is to use the con2fb_map lookup table to find the
framebuffer index.

Fixes: cfafca8067c6 ("fbdev: fbcon: console unregistration from unregister_framebuffer")
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

vt: Remove vc_panic_force_write

It was only used by the panic support in fbcon, which is now gone.
Remove this now dead code too.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Meng Xu <mengxu.gatech@gmail.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Thomas Meyer <thomas@m3y3r.de>
Cc: Mike Frysinger <vapier@chromium.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: David Lechner <david@lechnology.com>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180822085405.10787-2-daniel.vetter@ffwll.ch

fbdev: Drop FBINFO_CAN_FORCE_OUTPUT flag

This was only added for the drm's fbdev emulation support, so that it
would try harder to show the Oops.

Unfortunately this never really worked reliably, and in practice ended
up pushing the real Oops off the screen due to plentyfull locking,
sleep-while-atomic and other issues. So we removed all that support
from the fbdev emulation a while back. Aside: We've also removed the
kgdb support, for similar reasons.

Since it's such a small patch I figured I don't split this up into the
usual 3-phase removal.

Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Alexander Kapshuk <alexander.kapshuk@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: David Lechner <david@lechnology.com>
Cc: nouveau@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180822085405.10787-1-daniel.vetter@ffwll.ch

fbcon: Do not takeover the console from atomic context

Taking over the console involves allocating mem with GFP_KERNEL, talking
to drm drivers, etc. So this should not be done from an atomic context.

But the console-output trigger deferred console takeover may happen from an
atomic context, which leads to "BUG: sleeping function called from invalid
context" errors.

This commit fixes these errors by doing the deferred takeover from a
workqueue.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[b.zolnierkie: remove unused variable]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

fbcon: Only defer console takeover if the current console driver is the dummycon

We rely on dummycon's output notifier mechanism to defer the takeover.

If say vgacon is the current console driver then dummycon will never get
used so its output notifier will also never get called and fbcon never
takes over. This commit fixes this by only deferring the console takeover
if the current console driver is the dummycon driver.

This commit also moves the entirety of fbcon_start under the console_lock,
since the conswitchp which fbcon_start now checks is protected by it.

This commit also inlines fbcon_register_output_notifier, since we now
need a #ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER in fbcon_start
anyways because of the write access to the deferred_takeover variable,
this has the added advantage that it puts the
dummycon_register_output_notifier() call directly after the "conswitchp !=
&dummy_con" comparison making it clear why that check is there.

Note the arch setup code will set conswitchp to either dummy_con or
vga_con, in the cases where it gets set to vga_con even though their is
no vga_con present we rely on vga_con_startup() to set conswitchp to
dummy_con. vga_con_startup() is guaranteed to happen before
fb_console_init() as it gets called as a console_initcall where as
fb_console_init() gets called as a subsys_initcall.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

fbcon: introduce for_each_registered_fb() helper

Following pattern is often used:

for (i = 0; i < FB_MAX; i++) {
if (registered_fb[i]) {
...
}
}

Therefore, as Andy's suggestion, for_each_registered_fb() helper can
be introduced to make the code easier to read and write by reducing
indentation level. It also saves few lines of code in each occurrence.

This patch convert all part here at the same time.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yisheng Xie <ysxie@foxmail.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Lechner <david@lechnology.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

console/fbcon: Add support for deferred console takeover

Currently fbcon claims fbdevs as soon as they are registered and takes over
the console as soon as the first fbdev gets registered.

This behavior is undesirable in cases where a smooth graphical bootup is
desired, in such cases we typically want the contents of the framebuffer
(typically a vendor logo) to stay in place as is.

The current solution for this problem (on embedded systems) is to not
enable fbcon.

This commit adds a new FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER config option,
which when enabled defers fbcon taking over the console from the dummy
console until the first text is displayed on the console. Together with the
"quiet" kernel commandline option, this allows fbcon to still be used
together with a smooth graphical bootup, having it take over the console as
soon as e.g. an error message is logged.

Note the choice to detect the first console output in the dummycon driver,
rather then handling this entirely inside the fbcon code, was made after
2 failed attempts to handle this entirely inside the fbcon code. The fbcon
code is woven quite tightly into the console code, making this to only
feasible option.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

fbcon: Call WARN_CONSOLE_UNLOCKED() where applicable

Replace comments about places where the console lock should be held with
calls to WARN_CONSOLE_UNLOCKED() to assert that it is actually held.

Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

treewide: kmalloc() -> kmalloc_array()

The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

kmalloc(a * b, gfp)

with:
kmalloc_array(a * b, gfp)

as well as handling cases of:

kmalloc(a * b * c, gfp)

with:

kmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kmalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kmalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kmalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kmalloc
+ kmalloc_array
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kmalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kmalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kmalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kmalloc(sizeof(THING) * C2, ...)
|
kmalloc(sizeof(TYPE) * C2, ...)
|
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * E2
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>

console: Expand dummy functions for CFI

This expands the no-op dummy functions into full prototypes to avoid
indirect call mismatches when running under Control Flow Integrity
checking, like with Clang's -fsanitize=cfi.

Co-Developed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fbcon: Remove dmi quirk table

This is now all handled in the drivers and communicated through
fb_info.fbcon_rotate_hint.

Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171125193553.23986-8-hdegoede@redhat.com

fbcon: Add fbcon_rotate_hint to struct fb_info

On some hardware the LCD panel is not mounted upright in the casing,
but upside-down or rotated 90 degrees. In this case we want the console
to automatically be rotated to compensate.

The fbdev-driver may know about the need to rotate. Add a new
fbcon_rotate_hint field to struct fb_info, which gets initialized to -1.
If the fbdev-driver knows that some sort of rotation is necessary then
it can set this field to a FB_ROTATE_* value to tell the fbcon console
driver to rotate the console.

Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171125193553.23986-2-hdegoede@redhat.com

fbcon: Initialize ops->info early

During console takeover, which happens for all DRM/KMS setups using the
fbdev helpers, fbcon_startup() is called before fbcon_init() and as a
result con2fb_acquire_newinfo() will not be called (info->fbcon_par was
set to non-NULL in fbcon_startup()) to assign ops->info.

This causes the cursor_timer_handler() to unreference a NULL pointer.

Avoid this by unconditionally assigning ops->info during fbcon_startup()
so that it will be available early, but keep the additional assignment
in con2fb_acquire_newinfo() to support console remapping at runtime.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

video: fbdev: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly. One tracking pointer was added.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: David Lechner <david@lechnology.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
[b.zolnierkie: ported it over pxa3xx_gcu changes]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

fbcon: remove restriction on margin color

This removes the restriction on the value range of the fbcon=margin:
parameter. The color value really depends on the driver being used.

Signed-off-by: David Lechner <david@lechnology.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
[b.zolnierkie: ported over fbcon changes]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

fbcon: add fbcon=margin:<color> command line option

This adds a new command line option to select the fbcon margin color.

The motivation for this is screens where black does not blend into the
physical surroundings of the screen. For example, using an LCD (not the
backlit kind), white text on a black background is hard to read, so
inverting the colors is preferred. However, when you do this, most of the
screen is filled with white but the margins are still filled with black.
This makes a big, black, backwards 'L' on the screen. By setting
fbcon=margin:7, the margins will be filled with white and the LCD looks as
expected.

Signed-off-by: David Lechner <david@lechnology.com>
[b.zolnierkie: ported over fbcon changes]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

video/console: Add dmi quirk table for x86 systems which need fbcon rotation

Some x86 clamshell design devices use portrait tablet screens and a
display engine which cannot rotate in hardware, so we need to rotate
the fbcon to compensate.

This commit adds a DMI based quirk table which is initially populated with
4 such devices: The Asus T100HA, GPD Pocket, the GPD win and the I.T.Works
TW891, so that the console comes up in the right orientation on these
devices OOTB.

Unfortunately these (cheap) devices also typically have quite generic DMI
data, so we match on a combination of DMI data, screen resolution and a
list of known BIOS dates to avoid false positives.

Suggested-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
[b.zolnierkie: ported over fbcon changes]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

fbdev: Nuke FBINFO_MODULE

Instead check info->ops->owner, which amounts to the same.

Spotted because I want to remove the pile of broken and cargo-culted
fb_info->flags assignments in drm drivers.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

fbcon: Make fbcon a built-time depency for fbdev

There's a bunch of folks who're trying to make printk less
contended and faster, but there's a problem: printk uses the
console_lock, and the console lock has become the BKL for all things
fbdev/fbcon, which in turn pulled in half the drm subsystem under that
lock. That's awkward.

There reasons for that is probably just a historical accident:

- fbcon is a runtime option of fbdev, i.e. at runtime you can pick
whether your fbdev driver instances are used as kernel consoles.
Unfortunately this wasn't implemented with some module option, but
through some module loading magic: As long as you don't load
fbcon.ko, there's no fbdev console support, but loading it (in any
order wrt fbdev drivers) will create console instances for all fbdev
drivers.

- This was implemented through a notifier chain. fbcon.ko enumerates
all fbdev instances at load time and also registers itself as
listener in the fbdev notifier. The fbdev core tries to register new
fbdev instances with fbcon using the notifier.

- On top of that the modifier chain is also used at runtime by the
fbdev subsystem to e.g. control backlights for panels.

- The problem is that the notifier puts a mutex locking context
between fbdev and fbcon, which mixes up the locking contexts for
both the runtime usage and the register time usage to notify fbcon.
And at runtime fbcon (through the fbdev core) might call into the
notifier from a printk critical section while console_lock is held.

- This means console_lock must be an outer lock for the entire fbdev
subsystem, which also means it must be acquired when registering a
new framebuffer driver as the outermost lock since we might call
into fbcon (through the notifier) which would result in a locking
inversion if fbcon would acquire the console_lock from its notifier
callback (which it needs to register the console).

- console_lock can be held anywhere, since printk can be called
anywhere, and through the above story, plus drm/kms being an fbdev
driver, we pull in a shocking amount of locking hiercharchy
underneath the console_lock. Which makes cleaning up printk really
hard (not even splitting console_lock into an rwsem is all that
useful due to this).

There's various ways to address this, but the cleanest would be to
make fbcon a compile-time option, where fbdev directly calls the fbcon
register functions from register_framebuffer, or dummy static inline
versions if fbcon is disabled. Maybe augmented with a runtime knob to
disable fbcon, if that's needed (for debugging perhaps).

But this could break some users who rely on the magic "loading
fbcon.ko enables/disables fbdev framebuffers at runtime" thing, even
if that's unlikely. Hence we must be careful:

1. Create a compile-time dependency between fbcon and fbdev in the
least minimal way. This is what this patch does.

2. Wait at least 1 year to give possible users time to scream about
how we broke their setup. Unlikely, since all distros make fbcon
compile-in, and embedded platforms only compile stuff they know they
need anyway. But still.

3. Convert the notifier to direct functions calls, with dummy static
inlines if fbcon is disabled. We'll still need the fb notifier for the
other uses (like backlights), but we can probably move it into the fb
core (atm it must be built-into vmlinux).

4. Push console_lock down the call-chain, until it is down in
console_register again.

5. Finally start to clean up and rework the printk/console locking.

For context of this saga see

commit 50e244cc793d511b86adea24972f3a7264cae114
Author: Alan Cox <alan@linux.intel.com>
Date: Fri Jan 25 10:28:15 2013 +1000

fb: rework locking to fix lock ordering on takeover

plus the pile of commits on top that tried to make this all work
without terminally upsetting lockdep. We've uncovered all this when
console_lock lockdep annotations where added in

commit daee779718a319ff9f83e1ba3339334ac650bb22
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Sat Sep 22 19:52:11 2012 +0200

console: implement lockdep support for console_lock

On the patch itself:
- Switch CONFIG_FRAMEBUFFER_CONSOLE to be a boolean, using the overall
CONFIG_FB tristate to decided whether it should be a module or
built-in.

- At first I thought I could force the build depency with just a dummy
symbol that fbcon.ko exports and fb.ko uses. But that leads to a
module depency cycle (it works fine when built-in).

Since this tight binding is the entire goal the simplest solution is
to move all the fbcon modules (and there's a bunch of optinal
source-files which are each modules of their own, for no good
reason) into the overall fb.ko core module. That's a bit more than
what I would have liked to do in this patch, but oh well.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>