Now that we don't have tty->termios tied to drivers->tty we can untangle
the logic here. In addition we can push the removal logic out of the
destructor path.

At that point we can think about sorting out tty_port and console and all
the other ugly hangovers.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This will let us sort out a whole pile of tty related races. The
alternative would be to keep points and refcount the termios objects.
However
1. They are tiny anyway
2. Many devices don't use the stored copies
3. We can remove a pty special case
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We need to initialize the console only on the first open. This is
usually what is done in the ->install hook. vt used to do this in
->open. Now we move it to ->install and use newly added helper for
install: tty_port_install. It ensures tty->port to be set properly.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This is identical to tty_schedule_flip. So let us use that instead.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

set_get_cmap() ignored the result of {get,put}_user(), causing ioctl(vt,
{G,P}IO_CMAP, 0xdeadbeef) to silently fail.

Another side effect of this: calling the PIO_CMAP ioctl with an invalid
buffer would zero the default colormap and the palette for all vts (all
colors set to black).

Leave the default colormap intact and return -EFAULT when
reading/writing to the userspace buffer fails.
Signed-off-by: NMichael Gehring <mg@ebfe.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A prototype for kmsg records instead of a byte-stream buffer revealed
a couple of missing printk(KERN_CONT ...) uses. Subsequent calls produce
one record per printk() call, while all should have ended up in a single
record.

Instead of:
  ACPI: (supports S0 S5)
  ACPI: PCI Interrupt Link [LNKA] (IRQs 5 *10 11)
  hpet0: at MMIO 0xfed00000, IRQs 2 , 8 , 0

It prints:
  ACPI: (supports S0
   S5
  )
  ACPI: PCI Interrupt Link [LNKA] (IRQs
   5
   *10
   11
  )
  hpet0: at MMIO 0xfed00000, IRQs
   2
  , 8
  , 0

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: NKay Sievers <kay@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`
Signed-off-by: NDavid Howells <dhowells@redhat.com>

All num, magic and owner are set by alloc_tty_driver. No need to
re-set them on each allocation site.

pti driver sets something different to what it passes to
alloc_tty_driver. It is not a bug, since we don't use the lines
parameter in any way. Anyway this is fixed, and now we do the right
thing.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Acked-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We leave the existing paste mess alone and just fix up the vt side of
things.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some of this ventures into selection which is still a complete lost cause. We
are not making it any worse. It's completely busted anyway.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The font methods are console_lock covered. Unfortunately they don't extend
the lock over all the needed tests.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Keyboard struct lifetime is easy, but the locking is not and is completely
ignored by the existing code. Tackle this one head on

- Make the kbd_table private so we can run down all direct users
- Hoick the relevant ioctl handlers into the keyboard layer
- Lock them with the keyboard lock so they don't change mid keypress
- Add helpers for things like console stop/start so we isolate the poking
  around properly
- Tweak the braille console so it still builds

There are a couple of FIXME locking cases left for ioctls that are so hideous
they should be addressed in a later patch. After this patch the kbd_table is
private and all the keyboard jiggery pokery is in one place.

This update fixes speakup and also a memory leak in the original.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Even though this is valid C we should not mix C99 initializers with
obfuscated ANSI C. Stick to C99 and initialize c by its name.

Found by clang:
drivers/tty/vt/vt.c:262:55: warning: explicitly assigning a variable of
type 'unsigned int' to itself [-Wself-assign]
    struct vt_notifier_param param = { .vc = vc, unicode = unicode };
                                                 ~~~~~~~ ^ ~~~~~~~
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Traditional \E[2J sequence erases console display but scroll-back
buffer and underlying device (frame) buffer keep data that can be
accessed by scrolling console back.

This patch introduce new \E[J parameter 3 that allows to scramble
scroll-back buffer explicitly. Session locking programs (screen,
vlock) can use it to prevent attacker to browse locked console
history.
Signed-off-by: NPetr Písař <ppisar@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

remove invalid location line in each file header after location
moved from driver/char to driver/tty
Signed-off-by: NJovi Zhang <bookjovi@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/tty/vt/vt.c:892:2: warning: Value stored to 'old_screen_size' is never read
        old_screen_size = vc->vc_screenbuf_size;
        ^                 ~~~~~~~~~~~~~~~~~~~~~
drivers/tty/vt/vt.c:890:2: warning: Value stored to 'old_cols' is never read
	old_cols = vc->vc_cols;
	^          ~~~~~~~~~~~
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

These were missed the last time I cleaned this up
globally, because of code moving around or new code
getting merged.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

seems there's no longer need for using con_buf/conf_buf_mtx
as vcs_read/vcs_write buffer for user's data.

The do_con_write function, that was the other user of this,
is currently using its own kmalloc-ed buffer.

Not sure when this got changed, as I was able to find this code
in 2.6.9, but it's already gone as far as current git history
goes - 2.6.12-rc2.

AFAICS there's a behaviour change with the current change.
The lseek is not completely mutually exclusive with the
vcs_read/vcs_write - the file->f_pos might get updated
via lseek callback during the vcs_read/vcs_write processing.

I tried to find out if the prefered behaviour is to keep
this in sync within read/write/lseek functions, but I did
not find any pattern on different places.

I guess if user end up calling write/lseek from different
threads she should know what she's doing. If needed we
could use dedicated fd mutex/buffer.
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

printk()s without a priority level default to KERN_WARNING. To reduce
noise at KERN_WARNING, this patch set the priority level appriopriately
for unleveled printks()s. This should be useful to folks that look at
dmesg warnings closely.
Signed-off-by: NMandeep Singh Baines <msb@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The -rt patches change the console_semaphore to console_mutex.  As a
result, a quite large chunk of the patches changes all
acquire/release_console_sem() to acquire/release_console_mutex()

This commit makes things use more neutral function names which dont make
implications about the underlying lock.

The only real change is the return value of console_trylock which is
inverted from try_acquire_console_sem()

This patch also paves the way to switching console_sem from a semaphore to
a mutex.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: make console_trylock return 1 on success, per Geert]
Signed-off-by: NTorben Hohn <torbenh@gmx.de>
Cc: Thomas Gleixner <tglx@tglx.de>
Cc: Greg KH <gregkh@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes the build warnings in the tty code, and uses the proper
function for iterating over the console devices.
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

With framebuffer handover and multiple GPUs, we get into a
position where the fbcon unbinds the vesafb framebuffer for GPU 1,
but we still have a radeon framebuffer bound from GPU 0, so
we don't unregister the console driver. Then when we tried to bind
the new radeon framebuffer for GPU1 we never get to the bind
call as we fail due to the console being registered already.

This changes the return value to -EBUSY when the driver is
already registered and continues to bind for -EBUSY.
Signed-off-by: NDave Airlie <airlied@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

tty: add 'active' sysfs attribute to tty0 and console device

Userspace can query the actual virtual console, and the configured
console devices behind /dev/tt0 and /dev/console.

The last entry in the list of devices is the active device, analog
to the console= kernel command line option.

The attribute supports poll(), which is raised when the virtual
console is changed or /dev/console is reconfigured.
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

index 0000000..b138b66

The vt and other related code is moved into the drivers/tty/vt directory.
Acked-by: NArnd Bergmann <arnd@arndb.de>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

A notifier chain is called whenever the vt code modifies a terminal
content, except for one case which is when the modification comes
through writes to /dev/vcs* devices.  Let's add the missing notifier
invocation at the end of vcs_write() for that case too.
Signed-off-by: NNicolas Pitre <nicolas.pitre@canonical.com>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

After 02f0777a "vc_origin" is no
longer reset to the screen buffer before calling the con_init() hook
of the new console driver.

If the old driver wasn't using a fixed scanout buffer (e.g. the case
of vgacon) "vc_origin" may be a pointer to a VRAM location, and its
contents aren't guaranteed to be preserved after calling con_deinit()
on the old driver and con_init() on the new driver, i.e. the
subsequent console resize may fill the framebuffer with garbage.

It can be reproduced in the transition from vgacon to the nouveau
framebuffer driver: in that case the legacy VGA aperture "vc_origin"
points to becomes unreadable after fbcon_init().

This patch reverts the mentioned commit. To avoid the problem it
intended to fix, stop using "vc_scr_end" in vc_do_resize() to
calculate how many rows we have to copy (actually the code looks
simpler this way without the help of "vc_scr_end").
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Cc: qiaochong <qiaochong@loongson.cn>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Commit b45cfba4 (vt,console,kdb:
implement atomic console enter/leave functions) introduced the ability
to atomically change the console mode with kernel mode setting but did
not preserve the state of the console_blanked variable.

The console_blanked variable must be restored when executing the
con_debug_leave() or further kernel mode set changes (such as using
chvt X) will fail to correctly set the state of console.
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
CC: Andrew Morton <akpm@linux-foundation.org>

Fix the following new sparse warnings in vt.c introduced by the commit
b45cfba4 (vt,console,kdb: implement
atomic console enter/leave functions):

drivers/char/vt.c:197:5: warning: symbol 'saved_fg_console' was not declared. Should it be static?
drivers/char/vt.c:198:5: warning: symbol 'saved_last_console' was not declared. Should it be static?
drivers/char/vt.c:199:5: warning: symbol 'saved_want_console' was not declared. Should it be static?
drivers/char/vt.c:200:5: warning: symbol 'saved_vc_mode' was not declared. Should it be static?
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
CC: Andrew Morton <akpm@linux-foundation.org>

This takes all the tty references through the expected interface points so
we can refcount them.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The vt layer isn't safely handling reference counts to tty object on the input
side. Add a tty port structure to the vt layer in order to implement this using
the standard helpers.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The virtual console layer uses the BKL for various things that don't really
need it. Clean them out.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Jesse's initial patch commit said:

"At panic time (i.e.  when oops_in_progress is set) we should try a bit
harder to update the screen and make sure output gets to the VT, since
some drivers are capable of flipping back to it.

So make sure we try to unblank and update the display if called from a
panic context."

I've enhanced this to add a flag to the vc that console layer can set to
indicate they want this behaviour to occur.  This also adds support to
fbcon for that flag and adds an fb flag for drivers to indicate they want
to use the support.  It enables this for KMS drivers.
Signed-off-by: NDave Airlie <airlied@redhat.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: NJames Simmons <jsimmons@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NAndy Shevchenko <ext-andriy.shevchenko@nokia.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

According include/linux/console_struct.h,vc_scr_end is unsigned long.

struct vc_data {
    unsigned short  vc_num;         /* Console number */
    unsigned int    vc_cols;        /* [#] Console size */
    unsigned int    vc_rows;
    unsigned int    vc_size_row;        /* Bytes per row */
    unsigned int    vc_scan_lines;      /* # of scan lines */
    unsigned long   vc_origin;      /* [!] Start of real screen */
    unsigned long   vc_scr_end;     /* [!] End of real screen */
    unsigned long   vc_visible_origin;  /* [!] Top of visible window */
    unsigned int    vc_top, vc_bottom;  /* Scrolling region */
    const struct consw *vc_sw;
    unsigned short  *vc_screenbuf;
...
}
Signed-off-by: Nqiaochong <qiaochong@loongson.cn>
Cc: Greg KH <greg@kroah.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kernel will die on some platform when switch from vga mode to framebuffer
mode.  The reason of this bug is that bind_con_driver reset vc->vc_origin
to (unsigned long)vc->vc_screenbuf.

On vgacon vc->vc_origin is not releated to vc->vc_screenbuf,if set
vc->vc_origin to vc->vc_screenbuf,kernel will die on vc_do_resize.

static int vc_do_resize(struct tty_struct *tty, struct tty_struct *real_tty,
        struct vc_data *vc, unsigned int cols, unsigned int lines)
{
    unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
    unsigned int old_cols, old_rows, old_row_size, old_screen_size;
    unsigned int new_cols, new_rows, new_row_size, new_screen_size;
    unsigned int end, user;
...
        end = (old_rows > new_rows) ? old_origin +
            (old_row_size * new_rows) :
            vc->vc_scr_end;

...
/*
here for a test from vgacon to framebuffer:
old_origin=0x810814a0,end=0xb00b8fa0,vc->vc_origin=0x810814a0
the code bellow will copy memory from 0x810814a0 to 0xb00b8fa0,
this will cover kernel code,kernel died here.
*/

    while (old_origin < end) {

        scr_memcpyw((unsigned short *) new_origin,
                (unsigned short *) old_origin, rlth);
        if (rrem)
            scr_memsetw((void *)(new_origin + rlth),
                    vc->vc_video_erase_char, rrem);
        old_origin += old_row_size;
        new_origin += new_row_size;
    }

...
}

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Nqiaochong <qiaochong@loongson.cn>
Cc: Greg KH <greg@kroah.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The kernel console interface stores the number of lines it is
configured to use. The kdb debugger can greatly benefit by knowing how
many lines there are on the console for the pager functionality
without having the end user compile in the setting or have to
repeatedly change it at run time.
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
CC: David Airlie <airlied@linux.ie>
CC: Andrew Morton <akpm@linux-foundation.org>

These functions allow the kernel debugger to save and restore the
state of the system console.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
CC: David Airlie <airlied@linux.ie>
CC: Andrew Morton <akpm@linux-foundation.org>

This reverts commit 962400e8, which was
entirely bogus.

The code used to multiply the character offset by "vc->vc_cols", and
that's actually correct, because 'd' itself is an 'unsigned short'.  So
the pointer arithmetic already takes the size of a VGA character into
account.  Changing it to use vc_size_row (which is just "vc_cols"
shifted up to take the size of the character into account) ends up
multiplying with the VGA character size twice.

This got reported as bugs for various other subsystems, because what it
actually results in is writing the 16-bit vc_video_erase_char pattern
(usually 0x0720: 0x07 is the default attribute, 0x20 is ASCII space)
into some random other allocation.

So Markus ended up reporting this as a ext4 bug, while to Torsten Kaiser
it looked like a problem with KMS or libata.  Jeff Chua saw it in
different places.

And finally - Justin Mattock had slab poisoning enabled, and saw it as a
slab poison overwritten.  And bisected and reverted this to verify the
buggy commit.
Reported-by: NMarkus Trippelsdorf <markus@trippelsdorf.de>
Reported-by: NTorsten Kaiser <just.for.lkml@googlemail.com>
Reported-by: NJeff Chua <jeff.chua.linux@gmail.com>
Reported-by: NJustin P. Mattock <justinmattock@gmail.com>
Reported-bisected-and-tested-by: NJustin P. Mattock <justinmattock@gmail.com>
Acked-by: NDave Airlie <airlied@redhat.com>
Cc: Frank Pan <frankpzh@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The code uses vc->vc_cols instead of vc->vc_size_row by mistake, it
will cause half of the region which is going to clear remain
uncleared.
The issue happens in background consoles, so it's hard to observe.

Frank Pan
Signed-off-by: NFrank Pan <frankpzh@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>