Commit Graph

96 Commits

Author SHA1 Message Date
Jiri Slaby
8da443b1a4 tty/vt: consolemap: rename struct vc_data::vc_uni_pagedir*
As a follow-up to the commit 4173f018aa (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>
2022-06-27 14:17:12 +02:00
Jiri Slaby
4173f018aa tty/vt: consolemap: rename and document struct uni_pagedir
struct uni_pagedir contains 32 unicode page directories, so the name of
the structure is a bit misleading. Rename the structure to uni_pagedict,
so it looks like this:
struct uni_pagedict
  -> 32 page dirs
     -> 32 rows
       -> 64 glyphs

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220607104946.18710-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10 13:37:01 +02:00
Daniel Vetter
99b03ca651 Linux 5.16-rc5
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Merge v5.16-rc5 into drm-next

Thomas Zimmermann requested a fixes backmerge, specifically also for
96c5f82ef0 ("drm/vc4: fix error code in vc4_create_object()")

Just a bunch of adjacent changes conflicts, even the big pile of them
in vc4.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2021-12-14 10:24:28 +01:00
Javier Martinez Canillas
6a2d2ddf2c
drm: Move nomodeset kernel parameter to the DRM subsystem
The "nomodeset" kernel cmdline parameter is handled by the vgacon driver
but the exported vgacon_text_force() symbol is only used by DRM drivers.

It makes much more sense for the parameter logic to be in the subsystem
of the drivers that are making use of it.

Let's move the vgacon_text_force() function and related logic to the DRM
subsystem. While doing that, rename it to drm_firmware_drivers_only() and
make it return true if "nomodeset" was used and false otherwise. This is
a better description of the condition that the drivers are testing for.

Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211112133230.1595307-4-javierm@redhat.com
2021-11-27 13:52:22 +01:00
Maciej W. Rozycki
3dfac26e2e vgacon: Propagate console boot parameters before calling `vc_resize'
Fix a division by zero in `vgacon_resize' with a backtrace like:

vgacon_resize
vc_do_resize
vgacon_init
do_bind_con_driver
do_unbind_con_driver
fbcon_fb_unbind
do_unregister_framebuffer
do_register_framebuffer
register_framebuffer
__drm_fb_helper_initial_config_and_unlock
drm_helper_hpd_irq_event
dw_hdmi_irq
irq_thread
kthread

caused by `c->vc_cell_height' not having been initialized.  This has
only started to trigger with commit 860dafa902 ("vt: Fix character
height handling with VT_RESIZEX"), however the ultimate offender is
commit 50ec42edd9 ("[PATCH] Detaching fbcon: fix vgacon to allow
retaking of the console").

Said commit has added a call to `vc_resize' whenever `vgacon_init' is
called with the `init' argument set to 0, which did not happen before.
And the call is made before a key vgacon boot parameter retrieved in
`vgacon_startup' has been propagated in `vgacon_init' for `vc_resize' to
use to the console structure being worked on.  Previously the parameter
was `c->vc_font.height' and now it is `c->vc_cell_height'.

In this particular scenario the registration of fbcon has failed and vt
resorts to vgacon.  Now fbcon does have initialized `c->vc_font.height'
somehow, unlike `c->vc_cell_height', which is why this code did not
crash before, but either way the boot parameters should have been copied
to the console structure ahead of the call to `vc_resize' rather than
afterwards, so that first the call has a chance to use them and second
they do not change the console structure to something possibly different
from what was used by `vc_resize'.

Move the propagation of the vgacon boot parameters ahead of the call to
`vc_resize' then.  Adjust the comment accordingly.

Fixes: 50ec42edd9 ("[PATCH] Detaching fbcon: fix vgacon to allow retaking of the console")
Cc: stable@vger.kernel.org # v2.6.18+
Reported-by: Wim Osterholt <wim@djo.tudelft.nl>
Reported-by: Pavel V. Panteleev <panteleev_p@mcst.ru>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2110252317110.58149@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-25 18:23:57 +01:00
Linus Torvalds
adc12a7407 Merge branch 'resizex' (patches from Maciej)
Merge VT_RESIZEX fixes from Maciej Rozycki:
 "I got to the bottom of the issue with VT_RESIZEX recently discussed
  and came up with this small patch series, fixing an additional issue
  that I originally thought might be broken VGA hardware emulation with
  my laptop, which however turned out to be intertwined with the
  original problem and also a regression introduced somewhat later.

  The fix for that because the first patch, and then to make backporting
  feasible I had to put a revert of the offending change from last
  September next, followed by a proper fix for the framebuffer issue
  that change had tried to address.

  See individual change descriptions for details.

  These have been verified with true VGA hardware (a Trident TVGA8900
  ISA video adapter) using various combinations of `svgatextmode' and
  `setfont' command invocations to change both the VT size and the font
  size, and also switching between the text console and X11, both by
  starting/stopping the X server and by switching between VTs.

  All this to ensure bringing the behaviour of VGA text console back to
  correct operation as it used to be with Linux 2.6.18"

* emailed patches from Maciej W. Rozycki <macro@orcam.me.uk>:
  vt: Fix character height handling with VT_RESIZEX
  vt_ioctl: Revert VT_RESIZEX parameter handling removal
  vgacon: Record video mode changes with VT_RESIZEX
2021-05-13 11:12:51 -07:00
Maciej W. Rozycki
860dafa902 vt: Fix character height handling with VT_RESIZEX
Restore the original intent of the VT_RESIZEX ioctl's `v_clin' parameter
which is the number of pixel rows per character (cell) rather than the
height of the font used.

For framebuffer devices the two values are always the same, because the
former is inferred from the latter one.  For VGA used as a true text
mode device these two parameters are independent from each other: the
number of pixel rows per character is set in the CRT controller, while
font height is in fact hardwired to 32 pixel rows and fonts of heights
below that value are handled by padding their data with blanks when
loaded to hardware for use by the character generator.  One can change
the setting in the CRT controller and it will update the screen contents
accordingly regardless of the font loaded.

The `v_clin' parameter is used by the `vgacon' driver to set the height
of the character cell and then the cursor position within.  Make the
parameter explicit then, by defining a new `vc_cell_height' struct
member of `vc_data', set it instead of `vc_font.height' from `v_clin' in
the VT_RESIZEX ioctl, and then use it throughout the `vgacon' driver
except where actual font data is accessed which as noted above is
independent from the CRTC setting.

This way the framebuffer console driver is free to ignore the `v_clin'
parameter as irrelevant, as it always should have, avoiding any issues
attempts to give the parameter a meaning there could have caused, such
as one that has led to commit 988d076336 ("vt_ioctl: make VT_RESIZEX
behave like VT_RESIZE"):

 "syzbot is reporting UAF/OOB read at bit_putcs()/soft_cursor() [1][2],
  for vt_resizex() from ioctl(VT_RESIZEX) allows setting font height
  larger than actual font height calculated by con_font_set() from
  ioctl(PIO_FONT). Since fbcon_set_font() from con_font_set() allocates
  minimal amount of memory based on actual font height calculated by
  con_font_set(), use of vt_resizex() can cause UAF/OOB read for font
  data."

The problem first appeared around Linux 2.5.66 which predates our repo
history, but the origin could be identified with the old MIPS/Linux repo
also at: <git://git.kernel.org/pub/scm/linux/kernel/git/ralf/linux.git>
as commit 9736a3546de7 ("Merge with Linux 2.5.66."), where VT_RESIZEX
code in `vt_ioctl' was updated as follows:

 		if (clin)
-			video_font_height = clin;
+			vc->vc_font.height = clin;

making the parameter apply to framebuffer devices as well, perhaps due
to the use of "font" in the name of the original `video_font_height'
variable.  Use "cell" in the new struct member then to avoid ambiguity.

References:

[1] https://syzkaller.appspot.com/bug?id=32577e96d88447ded2d3b76d71254fb855245837
[2] https://syzkaller.appspot.com/bug?id=6b8355d27b2b94fb5cedf4655e3a59162d9e48e3

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org # v2.6.12+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-13 11:00:18 -07:00
Maciej W. Rozycki
d4d0ad57b3 vgacon: Record video mode changes with VT_RESIZEX
Fix an issue with VGA console font size changes made after the initial
video text mode has been changed with a user tool like `svgatextmode'
calling the VT_RESIZEX ioctl.  As it stands in that case the original
screen geometry continues being used to validate further VT resizing.

Consequently when the video adapter is firstly reprogrammed from the
original say 80x25 text mode using a 9x16 character cell (720x400 pixel
resolution) to say 80x37 text mode and the same character cell (720x592
pixel resolution), and secondly the CRTC character cell updated to 9x8
(by loading a suitable font with the KD_FONT_OP_SET request of the
KDFONTOP ioctl), the VT geometry does not get further updated from 80x37
and only upper half of the screen is used for the VT, with the lower
half showing rubbish corresponding to whatever happens to be there in
the video memory that maps to that part of the screen.  Of course the
proportions change according to text mode geometries and font sizes
chosen.

Address the problem then, by updating the text mode geometry defaults
rather than checking against them whenever the VT is resized via a user
ioctl.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: e400b6ec4e ("vt/vgacon: Check if screen resize request comes from userspace")
Cc: stable@vger.kernel.org # v2.6.24+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-13 11:00:18 -07:00
Stephen Kitt
0ae798fd96 vgacon: drop unused vga_init_done
Commit 973c096f6a ("vgacon: remove software scrollback support")
removed all uses of vga_init_done, so let's get rid of it entirely.

Signed-off-by: Stephen Kitt <steve@sk2.org>
Link: https://lore.kernel.org/r/20210215170837.1599706-1-steve@sk2.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-23 10:26:04 +01:00
Jiri Slaby
5a3c96e964 vgacon: comment on vga_rolled_over
Long time ago, I figured out what this number is good for and documented
that locally. But never submitted, so do it now.

Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10 09:34:06 +01:00
Jiri Slaby
cac8a63063 vgacon: drop BROKEN_GRAPHICS_PROGRAMS
BROKEN_GRAPHICS_PROGRAMS is defined when CONFIG_VGA_CONSOLE=y. And
vgacon.c is built exclusively in that case too. So the check for
BROKEN_GRAPHICS_PROGRAMS is pointless in vgacon.c as it is always true.
So remove the test and BROKEN_GRAPHICS_PROGRAMS completely.

This also eliminates the need for vga_font_is_default global as it is
only set and never read.

Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210105120239.28031-9-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07 16:17:31 +01:00
Linus Torvalds
973c096f6a vgacon: remove software scrollback support
Yunhai Zhang recently fixed a VGA software scrollback bug in commit
ebfdfeeae8 ("vgacon: Fix for missing check in scrollback handling"),
but that then made people look more closely at some of this code, and
there were more problems on the vgacon side, but also the fbcon software
scrollback.

We don't really have anybody who maintains this code - probably because
nobody actually _uses_ it any more.  Sure, people still use both VGA and
the framebuffer consoles, but they are no longer the main user
interfaces to the kernel, and haven't been for decades, so these kinds
of extra features end up bitrotting and not really being used.

So rather than try to maintain a likely unused set of code, I'll just
aggressively remove it, and see if anybody even notices.  Maybe there
are people who haven't jumped on the whole GUI badnwagon yet, and think
it's just a fad.  And maybe those people use the scrollback code.

If that turns out to be the case, we can resurrect this again, once
we've found the sucker^Wmaintainer for it who actually uses it.

Reported-by: NopNop Nop <nopitydays@gmail.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Cc: 张云海 <zhangyunhai@nsfocus.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-14 10:06:15 -07:00
Yunhai Zhang
ebfdfeeae8 vgacon: Fix for missing check in scrollback handling
vgacon_scrollback_update() always leaves enbough room in the scrollback
buffer for the next call, but if the console size changed that room
might not actually be enough, and so we need to re-check.

The check should be in the loop since vgacon_scrollback_cur->tail is
updated in the loop and count may be more than 1 when triggered by CSI M,
as Jiri's PoC:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>

int main(int argc, char** argv)
{
        int fd = open("/dev/tty1", O_RDWR);
        unsigned short size[3] = {25, 200, 0};
        ioctl(fd, 0x5609, size); // VT_RESIZE

        write(fd, "\e[1;1H", 6);
        for (int i = 0; i < 30; i++)
                write(fd, "\e[10M", 5);
}

It leads to various crashes as vgacon_scrollback_update writes out of
the buffer:
 BUG: unable to handle page fault for address: ffffc900001752a0
 #PF: supervisor write access in kernel mode
 #PF: error_code(0x0002) - not-present page
 RIP: 0010:mutex_unlock+0x13/0x30
...
 Call Trace:
  n_tty_write+0x1a0/0x4d0
  tty_write+0x1a0/0x2e0

Or to KASAN reports:
BUG: KASAN: slab-out-of-bounds in vgacon_scroll+0x57a/0x8ed

This fixes CVE-2020-14331.

Reported-by: 张云海 <zhangyunhai@nsfocus.com>
Reported-by: Yang Yingliang <yangyingliang@huawei.com>
Reported-by: Kyungtae Kim <kt0755@gmail.com>
Fixes: 15bdab959c ([PATCH] vgacon: Add support for soft scrollback)
Cc: stable@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Solar Designer <solar@openwall.com>
Cc: "Srivatsa S. Bhat" <srivatsa@csail.mit.edu>
Cc: Anthony Liguori <aliguori@amazon.com>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Yunhai Zhang <zhangyunhai@nsfocus.com>
Link: https://lore.kernel.org/r/9fb43895-ca91-9b07-ebfd-808cf854ca95@nsfocus.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-04 09:40:35 +02:00
Jiri Slaby
c0e4b3ad67 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>
2020-06-24 17:08:33 +02:00
Jiri Slaby
77bc14f273 vc: switch state to bool
The code currently uses bitfields to store true-false values. Switch all
of that to bools. Apart from the cleanup, it saves 20B of code as many
shifts, ANDs, and ORs became simple movzb's.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-24 17:08:31 +02:00
Jiri Slaby
b84ae3dc70 vt: introduce enum vc_intensity for intensity
Introduce names (en enum) for 0, 1, and 2 constants. We now have
VCI_HALF_BRIGHT, VCI_NORMAL, and VCI_BOLD instead.

Apart from the cleanup,
1) the enum allows for better type checking, and
2) this saves some code. No more fiddling with bits is needed in
   assembly now. (OTOH, the structure is larger.)

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-24 17:08:31 +02:00
Jiri Slaby
28bc24fc46 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>
2020-06-24 17:08:30 +02:00
Zhang Xiaoxu
513dc792d6 vgacon: Fix a UAF in vgacon_invert_region
When syzkaller tests, there is a UAF:
  BUG: KASan: use after free in vgacon_invert_region+0x9d/0x110 at addr
    ffff880000100000
  Read of size 2 by task syz-executor.1/16489
  page:ffffea0000004000 count:0 mapcount:-127 mapping:          (null)
  index:0x0
  page flags: 0xfffff00000000()
  page dumped because: kasan: bad access detected
  CPU: 1 PID: 16489 Comm: syz-executor.1 Not tainted
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
  rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
  Call Trace:
    [<ffffffffb119f309>] dump_stack+0x1e/0x20
    [<ffffffffb04af957>] kasan_report+0x577/0x950
    [<ffffffffb04ae652>] __asan_load2+0x62/0x80
    [<ffffffffb090f26d>] vgacon_invert_region+0x9d/0x110
    [<ffffffffb0a39d95>] invert_screen+0xe5/0x470
    [<ffffffffb0a21dcb>] set_selection+0x44b/0x12f0
    [<ffffffffb0a3bfae>] tioclinux+0xee/0x490
    [<ffffffffb0a1d114>] vt_ioctl+0xff4/0x2670
    [<ffffffffb0a0089a>] tty_ioctl+0x46a/0x1a10
    [<ffffffffb052db3d>] do_vfs_ioctl+0x5bd/0xc40
    [<ffffffffb052e2f2>] SyS_ioctl+0x132/0x170
    [<ffffffffb11c9b1b>] system_call_fastpath+0x22/0x27
    Memory state around the buggy address:
     ffff8800000fff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00
     00 00
     ffff8800000fff80: 00 00 00 00 00 00 00 00 00 00 00 00 00
     00 00 00
    >ffff880000100000: ff ff ff ff ff ff ff ff ff ff ff ff ff
     ff ff ff

It can be reproduce in the linux mainline by the program:
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <sys/ioctl.h>
  #include <linux/vt.h>

  struct tiocl_selection {
    unsigned short xs;      /* X start */
    unsigned short ys;      /* Y start */
    unsigned short xe;      /* X end */
    unsigned short ye;      /* Y end */
    unsigned short sel_mode; /* selection mode */
  };

  #define TIOCL_SETSEL    2
  struct tiocl {
    unsigned char type;
    unsigned char pad;
    struct tiocl_selection sel;
  };

  int main()
  {
    int fd = 0;
    const char *dev = "/dev/char/4:1";

    struct vt_consize v = {0};
    struct tiocl tioc = {0};

    fd = open(dev, O_RDWR, 0);

    v.v_rows = 3346;
    ioctl(fd, VT_RESIZEX, &v);

    tioc.type = TIOCL_SETSEL;
    ioctl(fd, TIOCLINUX, &tioc);

    return 0;
  }

When resize the screen, update the 'vc->vc_size_row' to the new_row_size,
but when 'set_origin' in 'vgacon_set_origin', vgacon use 'vga_vram_base'
for 'vc_origin' and 'vc_visible_origin', not 'vc_screenbuf'. It maybe
smaller than 'vc_screenbuf'. When TIOCLINUX, use the new_row_size to calc
the offset, it maybe larger than the vga_vram_size in vgacon driver, then
bad access.
Also, if set an larger screenbuf firstly, then set an more larger
screenbuf, when copy old_origin to new_origin, a bad access may happen.

So, If the screen size larger than vga_vram, resize screen should be
failed. This alse fix CVE-2020-8649 and CVE-2020-8647.

Linus pointed out that overflow checking seems absent. We're saved by
the existing bounds checks in vc_do_resize() with rather strict
limits:

	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
		return -EINVAL;

Fixes: 0aec4867dc ("[PATCH] SVGATextMode fix")
Reference: CVE-2020-8647 and CVE-2020-8649
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
[danvet: augment commit message to point out overflow safety]
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200304022429.37738-1-zhangxiaoxu5@huawei.com
2020-03-06 21:06:34 +01:00
Kefeng Wang
3e3d38bd0d vgacon: Use pr_warn instead of pr_warning
As said in commit f2c2cbcc35 ("powerpc: Use pr_warn instead of
pr_warning"), removing pr_warning so all logging messages use a
consistent <prefix>_warn style. Let's do it.

Link: http://lkml.kernel.org/r/20191018031850.48498-24-wangkefeng.wang@huawei.com
To: linux-kernel@vger.kernel.org
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-10-18 15:01:56 +02:00
Nicolas Pitre
bfd8d8fe98 vgacon: unconfuse vc_origin when using soft scrollback
When CONFIG_VGACON_SOFT_SCROLLBACK is selected, the VGA display memory
index and vc_visible_origin don't change when scrollback is activated.
The actual screen content is saved away and the scrollbackdata is copied
over it. However the vt code, and /dev/vcs devices in particular, still
expect vc_origin to always point at the actual screen content not the
displayed scrollback content.

So adjust vc_origin to point at the saved screen content when scrollback
is active and set it back to vc_visible_origin when restoring the screen.

This fixes /dev/vcsa<n> that return scrollback content when they
shouldn't (onli /dev/vcsa without a number should), and also fixes
/dev/vcsu that should return scrollback content when scrollback is
active but currently doesn't.

An unnecessary call to vga_set_mem_top() is also removed.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18 13:45:22 +01:00
Lyude Paul
ff459c2dc0 video/console/vgacon: Print big fat warning with nomodeset
It's been a pretty good while since kernel modesetting was introduced.
It has almost entirely replaced previous solutions which required
userspace modesetting, and I can't even recall any drivers off the top
of my head for modern day hardware that don't only support one or the
other. Even nvidia's ugly blob does not require the use of nomodeset,
and only requires that nouveau be blacklisted.

Effectively, the only thing nomodeset does in the year 2018 is disable
your graphics drivers. Since VESA is a thing, this will give many users
the false impression that they've actually fixed an issue they were
having with their machine simply because the laptop will boot up to a
degraded GUI. This of course, is never actually the case.

Things get even worse when you consider that there's still an enormous
amount of tutorials users find on the internet that still suggest adding
nomodeset, along with various users who have been around long enough to
still suggest it.

There really isn't any legitimate reason I can see for this to be an
option that's used by anyone else other then developers, or properly
informed users. So, let's end the confusion and start printing warnings
whenever it's enabled.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Jan H. Schönherr" <jschoenh@amazon.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
2018-07-24 19:11:26 +02:00
Kees Cook
c396a5bf45 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>
2018-02-27 10:17:33 +01:00
Bjorn Helgaas
c82084117f vgacon: Set VGA struct resource types
Set the resource type when we reserve VGA-related I/O port resources.

The resource code doesn't actually look at the type, so it inserts
resources without a type in the tree correctly even without this change.
But if we ever print a resource without a type, it looks like this:

  vga+ [??? 0x000003c0-0x000003df flags 0x0]

Setting the type means it will be printed correctly as:

  vga+ [io  0x000003c0-0x000003df]

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-12-18 23:07:43 -06:00
Jan H. Schönherr
b9a58de545 vgacon: Prevent faulty bootparams.screeninfo from causing harm
If a zero for the number of colums or rows manages to slip through,
gotoxy() will underflow vc->vc_pos, causing the next action on the
referenced memory to end with a page fault.

Make the check in vgacon_startup() more pessimistic to prevent that.

Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
2017-09-04 16:00:50 +02:00
Manuel Schölling
1a336c9346 console: Make persistent scrollback a boot parameter
The impact of the persistent scrollback feature on the code size is
rather small, so the config option is removed. The feature stays
disabled by default and can be enabled by using the boot command line
parameter 'vgacon.scrollback_persistent=1' or by setting
VGACON_SOFT_SCROLLBACK_PERSISTENT_ENABLE_BY_DEFAULT=y.

Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de>
Suggested-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 11:54:02 +01:00
Manuel Schölling
aabd31c421 console: Add persistent scrollback buffers for all VGA consoles
Add a scrollback buffers for each VGA console. The benefit is that
the scrollback history is not flushed when switching between consoles
but is persistent.
The buffers are allocated on demand when a new console is opened.

This breaks tools like clear_console that rely on flushing the
scrollback history by switching back and forth between consoles
which is why this feature is disabled by default.
Use the escape sequence \e[3J instead for flushing the buffer.

Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de>
Reviewed-by: Andrey Utkin <andrey_utkin@fastmail.com>
Tested-by: Andrey Utkin <andrey_utkin@fastmail.com>
Tested-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 11:54:02 +01:00
Manuel Schölling
bcd375f7f7 console: Add callback to flush scrollback buffer to consw struct
This new callback is in preparation for persistent scrollback buffer
support for VGA consoles.
With a single scrollback buffer for all consoles, we could flush the
buffer just by invocating consw->con_switch(). But when each VGA console
has its own scrollback buffer, we need a new callback to tell the
video console driver which buffer to flush.

Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de>
Reviewed-by: Andrey Utkin <andrey_utkin@fastmail.com>
Tested-by: Andrey Utkin <andrey_utkin@fastmail.com>
Tested-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 11:54:02 +01:00
Manuel Schölling
66da39eb91 console: Move scrollback data into its own struct
This refactoring is in preparation for persistent scrollback
support for VGA console.

Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de>
Reviewed-by: Andrey Utkin <andrey_utkin@fastmail.com>
Tested-by: Andrey Utkin <andrey_utkin@fastmail.com>
Tested-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 11:54:02 +01:00
Jiri Slaby
b9c8b7fc25 vgacon: remove prehistoric macros
These macros:
* CAN_LOAD_EGA_FONTS
* CAN_LOAD_PALETTE
* TRIDENT_GLITCH
* VGA_CAN_DO_64KB
* SLOW_VGA
are either always set or always unset. They come from the linux 2.1
times. And given nobody switched them to some configurable options, I
assume nobody actually uses them.

So remove the macros and leave in place appropriate branches of the
conditional code.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: <linux-fbdev@vger.kernel.org>
Cc: <linux-doc@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27 16:37:44 +02:00
Jiri Slaby
96fd955423 vgacon: switch boolean variables to bool
These variables:
* vga_can_do_color
* vgacon_text_mode_force
* vga_font_is_default
* vga_hardscroll_enabled
* vga_hardscroll_user_enable
* vga_init_done
* vga_is_gfx
* vga_palette_blanked
* vga_512_chars
are used exclusively as a boolean value, so make them really a bool.

Remove also useless "? true : false".

__read_mostly annotations removed too as they obfuscate the code and I
doubt they improve anything measurable given the variables are used
from .con_scroll, .con_startup and such.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: <linux-fbdev@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27 16:37:44 +02:00
Jiri Slaby
35cc56f9a3 tty: vgacon+sisusb, move scrolldelta to a common helper
The code is mirrorred in scrolldelta implementations of both vgacon
and sisusb. Let's move the code to a separate helper where we will
perform a common cleanup and further changes.

While we are moving the code, make it linear and save one indentation
level. This is done by returning from the "!lines" then-branch
immediatelly. This allows flushing the else-branch 1 level to the
left, obviously.

Few more new lines and comments were added too.

And do not forget to export the helper function given sisusb can be
built as module.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: <linux-fbdev@vger.kernel.org>
Cc: <linux-usb@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27 16:37:44 +02:00
Jiri Slaby
d705ff3818 tty: vt, cleanup and document con_scroll
Scrolling helpers scrup and scrdown both accept 'top' and 'bottom' as
unsigned int. Number of lines 'nr' is accepted as int, but all callers
pass down unsigned too. So change the type of 'nr' to unsigned too.
Now, promote unsigned int from the helpers up to the con_scroll
hook which actually accepted all those as signed int.

Next, the 'dir' parameter can have only two values and we define
constants for that: SM_UP and SM_DOWN. Switch them to enum and do
proper type checking on 'dir' too.

Finally, document the behaviour of the hook.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: <linux-fbdev@vger.kernel.org>
Cc: <linux-usb@vger.kernel.org>
Cc: <linux-parisc@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27 16:37:43 +02:00
Jiri Slaby
6ca8dfd781 tty: vt, convert more macros to functions
Namely convert:
* IS_FG -> con_is_fg
* DO_UPDATE -> con_should_update
* CON_IS_VISIBLE -> con_is_visible

DO_UPDATE was a weird name for a yes/no answer, so the new name is
con_should_update.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: linux-usb@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25 09:04:48 -07:00
Jiri Slaby
52ad1f38b4 tty: vt, remove consw->con_bmove
It is never called since commit 81732c3b2f (tty vt: Fix line
garbage in virtual console on command line edition) in 3.7. So remove
all the callbacks.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Cc: linux-usb@vger.kernel.org
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25 09:04:48 -07:00
Jiri Slaby
709280da62 tty: vt, consw->con_set_palette cleanup
* allow NULL consw->con_set_palette (some consoles define an empty
  hook)
* => remove empty hooks now
* return value of consw->con_set_palette is never checked => make the
  function void
* document consw->con_set_palette a bit

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Cc: linux-usb@vger.kernel.org
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25 09:04:48 -07:00
Jiri Slaby
97293de977 tty: vt, consw->con_scrolldelta cleanup
* allow NULL consw->con_scrolldelta (some consoles define an empty
  hook)
* => remove empty hooks now
* return value of consw->con_scrolldelta is never checked => make the
  function void
* document consw->con_scrolldelta a bit

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Cc: linux-usb@vger.kernel.org
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25 09:04:48 -07:00
Jiri Slaby
8ede5cce4f tty: vt, make color_table const
This means all ->con_set_palette have to have the second parameter
const too now.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 09:26:55 -07:00
Mark Rustad
89f0244e7f video/console: Resolve several shadow warnings
Resolve shadow warnings that appear in W=2 builds by renaming
the "state" global to "vgastate".

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2014-10-22 09:56:41 +03:00
Dave Airlie
884d6147ba Merge tag 'drm-intel-fixes-2014-06-17' of git://anongit.freedesktop.org/drm-intel into drm-next
First round of fixes for 3.16-rc, mostly cc: stable, and the vt/vgacon
fixes from Daniel [1] to avoid hangs and unclaimed register errors on
module load/reload.

* tag 'drm-intel-fixes-2014-06-17' of git://anongit.freedesktop.org/drm-intel:
  drm/i915/bdw: remove erroneous chv specific workarounds from bdw code
  drm/i915: fix possible refcount leak when resetting forcewake
  drm/i915: Reorder semaphore deadlock check
  drm/i95: Initialize active ring->pid to -1
  drm/i915: set backlight duty cycle after backlight enable for gen4
  drm/i915: Avoid div-by-zero when pixel_multiplier is zero
  drm/i915: Disable FBC by default also on Haswell and later
  drm/i915: Kick out vga console
  drm/i915: Fixup global gtt cleanup
  vt: Don't ignore unbind errors in vt_unbind
  vt: Fix up unregistration of vt drivers
  vt: Fix replacement console check when unbinding
2014-06-19 10:54:35 +10:00
Daniel Vetter
a4de05268e drm/i915: Kick out vga console
Touching the VGA resources on an IVB EFI machine causes hard hangs when
we then kick out the efifb. Ouch.

Apparently this also prevents unclaimed register errors on hsw and
hard machine hangs on my i855gm when trying to unbind fbcon.

Also, we want this to make I915_FBDEV=n safe.

v2: Rebase and pimp commit message.

v3: We also need to unregister the vga console, otherwise the unbind
of the fb console before module unload might resurrect it again.

v4: Ignore errors when the vga console is already unregistered - this
can happen when e.g. reloading i915.ko.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67813
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: linux-fbdev@vger.kernel.org
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-06-09 21:03:47 +02:00
Takashi Iwai
e4bdab70dd console: Use explicit pointer type for vc_uni_pagedir* fields
The vc_data.vc_uni_pagedir filed is currently long int, supposedly to
be served generically.  This, however, leads to lots of cast to
pointer, and rather it worsens the readability significantly.

Actually, we have now only a single uni_pagedir map implementation,
and this won't change likely.  So, it'd be much more simple and
error-prone to just use the exact pointer for struct uni_pagedir
instead of long.

Ditto for vc_uni_pagedir_loc.  It's a pointer to the uni_pagedir, thus
it can be changed similarly to the exact type.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 13:37:21 -07:00
Takashi Iwai
0f2893f0d1 vgacon: Fix & cleanup refcounting
The vgacon driver prepares a two element array of uni_pagedir_loc and
uses the second item as its own reference counter for sharing the
uni_pagedir.  And the code assumes blindly that the second item is
available if the assigned vc_uni_pagedir isn't the standard one, which
might be wrong (although currently it's so).

This patch fixes that wrong assumption, and gives a slight cleanup
along with it: namely, instead of array, just give the uni_pagedir_loc
and a separate refcount variable.  It makes the code a bit more
understandable at first glance.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 13:37:21 -07:00
Dave Airlie
0ab3691fa8 vgacon: fix missing include.
This fixes the build error.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-06-27 10:08:04 +10:00
Marcelo Tosatti
7e6d72c15f vgacon.c: add cond reschedule points in vgacon_do_font_op
Booting a 64-vcpu KVM guest, with CONFIG_PREEMPT_VOLUNTARY,
can result in a soft lockup:

BUG: soft lockup - CPU#41 stuck for 67s! [setfont:1505]
 RIP: 0010:[<ffffffff812c48da>]
[<ffffffff812c48da>] vgacon_do_font_op.clone.0+0x1ba/0x550

This is due to the 8192 (cmapsz) IO operations taking longer than expected
due to lock contention in QEMU.

Add conditional resched points in between writes allowing other tasks to
execute.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-06-26 16:27:55 +10:00
Dave Airlie
2a24830723 vgacon/vt: clear buffer attributes when we load a 512 character font (v2)
When we switch from 256->512 byte font rendering mode, it means the
current contents of the screen is being reinterpreted. The bit that holds
the high bit of the 9-bit font, may have been previously set, and thus
the new font misrenders.

The problem case we see is grub2 writes spaces with the bit set, so it
ends up with data like 0x820, which gets reinterpreted into 0x120 char
which the font translates into G with a circumflex. This flashes up on
screen at boot and is quite ugly.

A current side effect of this patch though is that any rendering on the
screen changes color to a slightly darker color, but at least the screen
no longer corrupts.

v2: as suggested by hpa, always clear the attribute space, whether we
are are going to or from 512 chars.

Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-02-07 12:37:03 +10:00
Thomas Gleixner
6b2c1800f1 locking, video: Annotate vga console lock as raw
The vga_lock lock can be taken in atomic context and therefore
cannot be preempted on -rt - annotate it.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-09-13 11:12:04 +02:00
Amerigo Wang
63b1dd07fa video: fix some comments in drivers/video/console/vgacon.c
Now vgacon_scrollback_startup() uses slab, not bootmem,
the comment above it is obsolete, so does __init_refok.

Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2011-01-25 15:10:21 +09:00
Yannick Heneault
554ec37aca vgacon: check for efi machine
It seems there is a small problem of VGA palette corruption on EFI
machine.  When the kernel initializes the architecture, it checks if the
machine is a EFI machine and assumes that a VGA console can exist.

When it initializes the console in vgacon_startup it checks if it can
really use the VGA console.  I think this is where a check is missing.
Currently, the function can fail if a VESA boot mode is detected but not if
a EFI boot mode was used.

Thus vgacon_startup() doesn't fail and initialize the video card for a real
VGA mode.  This function changes the first 16entries of the VGA palette.

When the efifb driver kicks in, the palette is not restored to default
ramp value, thus the 16 first entry remain in a modified state.  The
following patch prevent this corruption.

Signed-off-by: Yannick Heneault <yheneaul@matrox.com>
Cc: Dave Airlie <airlied@linux.ie>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:12 -08:00
Arnd Bergmann
451a3c24b0 BKL: remove extraneous #include <smp_lock.h>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-17 08:59:32 -08:00
Arnd Bergmann
83ceb67d7d tty: fix console_sem lock order
vgacon_do_font_op releases and reacquires the BTM while holding
console_sem. This violates the rule that BTM has to be the
outer lock whenever we hold both.

There does not seem to be any reason to give up the BTM here,
so just stop doing that.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 13:47:43 -07:00