Commit b45cfba4e9 (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: Jason Wessel <jason.wessel@windriver.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
CC: Andrew Morton <akpm@linux-foundation.org>
Fix the following new sparse warnings in vt.c introduced by the commit
b45cfba4e9 (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: Jason Wessel <jason.wessel@windriver.com>
Reviewed-by: Jesse 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: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg 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: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg 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: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg 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: Dave Airlie <airlied@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: James Simmons <jsimmons@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg 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: qiaochong <qiaochong@loongson.cn>
Cc: Greg KH <greg@kroah.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: qiaochong <qiaochong@loongson.cn>
Cc: Greg KH <greg@kroah.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jesse 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: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
CC: David Airlie <airlied@linux.ie>
CC: Andrew Morton <akpm@linux-foundation.org>
This reverts commit 962400e8fd, 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: Markus Trippelsdorf <markus@trippelsdorf.de>
Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com>
Reported-by: Jeff Chua <jeff.chua.linux@gmail.com>
Reported-by: Justin P. Mattock <justinmattock@gmail.com>
Reported-bisected-and-tested-by: Justin P. Mattock <justinmattock@gmail.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Cc: Frank Pan <frankpzh@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus 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: Frank Pan <frankpzh@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use memdup_user when user data is immediately copied into the
allocated region.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression from,to,size,flag;
position p;
identifier l1,l2;
@@
- to = \(kmalloc@p\|kzalloc@p\)(size,flag);
+ to = memdup_user(from,size);
if (
- to==NULL
+ IS_ERR(to)
|| ...) {
<+... when != goto l1;
- -ENOMEM
+ PTR_ERR(to)
...+>
}
- if (copy_from_user(to, from, size) != 0) {
- <+... when != goto l2;
- -EFAULT
- ...+>
- }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In particular, several occurances of funny versions of 'success',
'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address',
'beginning', 'desirable', 'separate' and 'necessary' are fixed.
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Joe Perches <joe@perches.com>
Cc: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Remove unused fields in drivers/char/vt.c
variables orig_buf and orig_count are assigned but never used.
Signed-off-by: Shahar Havivi <shaharh@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
For embedded systems, the blinking cursor at startup time can be annoying
and unintended. Add a new kernel parameter to change the default cursor
shape.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: Daniel Mack <daniel@caiaq.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: David Newall <davidn@davidnewall.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel offers with TIOCL_GETKMSGREDIRECT ioctl() the possibility to
redirect the kernel messages to a specific console.
However, since it's not possible to switch to the kernel message console
after a panic(), it would be nice if the kernel would print the panic
message on the current console.
This patch series adds a new interface to access the global kmsg_redirect
variable by a function to be able to use it in code where
CONFIG_VT_CONSOLE is not set (kernel/panic.c).
This patch:
Instead of using and exporting a global value kmsg_redirect, introduce a
function vt_kmsg_redirect() that both can set and return the console where
messages are printed.
Change all users of kmsg_redirect (the VT code itself and kernel/power.c)
to the new interface.
The main advantage is that vt_kmsg_redirect() can also be used when
CONFIG_VT_CONSOLE is not set.
Signed-off-by: Bernhard Walle <bernhard@bwalle.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for setting a global default for whether or not a visible
cursor should be enabled when creating VCs. The default will be to do so,
unless overridden by the user at boot time or by a driver.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
LKML-Reference: <1258143251-5818-1-git-send-email-mjg@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
The VT specific compat_ioctl handlers are the only ones
in common code that require the BKL. Moving them into
the vt driver lets us remove the BKL from the other handlers
and cleans up the code.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is needed and requested in various forms for ConsoleKit, screenblank
handling and the like so do the job with a single interface. Also build the
interface so that unlike VT_WAITACTIVE and friends it won't miss events.
FIXME: Should this be a waitactive ioctl or a new device file you can poll
and read events from. We need the code anyway to fix up the existing broken
wait for console switch logic but the ConsoleKit people would prefer the
new device to the ioctl we have here
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
fix the following 'make includecheck' warning:
drivers/char/vt.c: linux/device.h is included more than once.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Many years ago when this driver was written, it had a use, but these
days it's nothing but trouble and distributions should not enable it
in any situation.
Pretty much every console device a sparc machine could see has a
bonafide real driver, making the PROM console hack unnecessary.
If any new device shows up, we should write a driver instead of
depending upon this crutch to save us. We've been able to take care
of this even when no chip documentation exists (sunxvr500, sunxvr2500)
so there are no excuses.
Signed-off-by: David S. Miller <davem@davemloft.net>
Bootmem is not used for the vt screen buffer anymore as slab is now
available at the time the console is initialized.
Get rid of the now superfluous distinction between slab and bootmem,
it's always slab.
This also fixes a kmalloc leak which Catalin described thusly:
Commit a5f4f52e ("vt: use kzalloc() instead of the bootmem allocator")
replaced the alloc_bootmem() with kzalloc() but didn't set vc_kmalloced to
1 and the memory block is later leaked. The corresponding kmemleak trace:
unreferenced object 0xdf828000 (size 8192):
comm "swapper", pid 0, jiffies 4294937296
backtrace:
[<c006d473>] __save_stack_trace+0x17/0x1c
[<c000d869>] log_early+0x55/0x84
[<c01cfa4b>] kmemleak_alloc+0x33/0x3c
[<c006c013>] __kmalloc+0xd7/0xe4
[<c00108c7>] con_init+0xbf/0x1b8
[<c0010149>] console_init+0x11/0x20
[<c0008797>] start_kernel+0x137/0x1e4
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT
This will make hardirq.h inclusion cheaper for every PREEMPT=n config
(which includes allmodconfig/allyesconfig, BTW)
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The console blank timer is currently hardcoded to 10*60 seconds which
might be annoying on systems with no input devices attached to wake up the
console again. Especially during development, disabling the screen saver
can be handy - for example when debugging the root fs mount mechanism or
other scenarios where no userspace program could be started to do that at
runtime from userspace.
This patch defines a core_param for the variable in charge which allows
users to entirely disable the blank feature at boot time by setting it 0.
The value can still be overwritten at runtime using the standard ioctl
call - this just allows to conditionally change the default.
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This file is no longer annotated for false positives but the kmemleak.h
include was still present.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Alan Cox <alan.cox@linux.intel.com>
* 'for-linus' of git://linux-arm.org/linux-2.6:
kmemleak: Add the corresponding MAINTAINERS entry
kmemleak: Simple testing module for kmemleak
kmemleak: Enable the building of the memory leak detector
kmemleak: Remove some of the kmemleak false positives
kmemleak: Add modules support
kmemleak: Add kmemleak_alloc callback from alloc_large_system_hash
kmemleak: Add the vmalloc memory allocation/freeing hooks
kmemleak: Add the slub memory allocation/freeing hooks
kmemleak: Add the slob memory allocation/freeing hooks
kmemleak: Add the slab memory allocation/freeing hooks
kmemleak: Add documentation on the memory leak detector
kmemleak: Add the base support
Manual conflict resolution (with the slab/earlyboot changes) in:
drivers/char/vt.c
init/main.c
mm/slab.c
Now that kmem_cache_init() happens before console_init(), we should use
kzalloc() and not the bootmem allocator.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
There are allocations for which the main pointer cannot be found but
they are not memory leaks. This patch fixes some of them. For more
information on false positives, see Documentation/kmemleak.txt.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This reverts commit 1c55f18717.
Ingo Brueckl was assuming that reverting to 1:1 mapping for chars >= 128
was not useful, but it happens to be: due to the limitations of the
Linux console, when a blind user wants to read BIG5 on it, he has no
other way than loading a font without SFM and let the 1:1 mapping permit
the screen reader to get the BIG5 encoding.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During bootup performance tracing I noticed many occurrences of
vca* device creation and removal, leading to the usual userspace
uevent processing, which are, in this case, rather pointless.
A simple test showing the kernel timing (not including all the
work userspace has to do), gives us these numbers:
$ time for i in `seq 1000`; do echo a > /dev/tty2; done
real 0m1.142s
user 0m0.015s
sys 0m0.540s
If we move the hook for the vcs* driver core devices from the
tty "binding" to the vc allocation/deallocation, which is what
the vcs* devices represent, we get the following numbers:
$ time for i in `seq 1000`; do echo a > /dev/tty2; done
real 0m0.152s
user 0m0.030s
sys 0m0.072s
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Building an allnoconfig kernel, sparse asked whether these could be
static, so I checked, and they are only used in the file where they are
declared.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have special case logic for resizing pty/tty pairs. We also have a per
driver resize method so for the pty case we should use it.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes the loss of echoed (and other ldisc-generated characters) when
the tty is stopped or when the driver output buffer is full (happens
frequently for input during continuous program output, such as ^C)
and removes the Big Kernel Lock from the N_TTY line discipline.
Adds an "echo buffer" to the N_TTY line discipline that handles all
ldisc-generated output (including echoed characters). Along with the
loss of characters, this also fixes the associated loss of sync between
tty output and the ldisc state when characters cannot be immediately
written to the tty driver.
The echo buffer stores (in addition to characters) state operations that need
to be done at the time of character output (like management of the column
position). This allows echo to cooperate correctly with program output,
since the ldisc state remains consistent with actual characters written.
Since the echo buffer code now isolates the tty column state code
to the process_out* and process_echoes functions, we can remove the
Big Kernel Lock (BKL) and replace it with mutex locks.
Highlights are:
* Handles echo (and other ldisc output) when tty driver buffer is full
- continuous program output can block echo
* Saves echo when tty is in stopped state (e.g. ^S)
- (e.g.: ^Q will correctly cause held characters to be released for output)
* Control character pairs (e.g. "^C") are treated atomically and not
split up by interleaved program output
* Line discipline state is kept consistent with characters sent to
the tty driver
* Remove the big kernel lock (BKL) from N_TTY line discipline
Signed-off-by: Joe Peterson <joe@skyrush.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For the console, there is a 1:1 mapping of glyphs which cannot be found
in the current font. This seems to be meant as a kind of 'emergency
fallback' for fonts without unicode mapping which otherwise would
display nothing readable on the screen.
At the moment it affects all chars for which no substitution character
is defined. In particular this means that for all chars (>= 128) where
there is no iso88591-1/unicode character (e.g. control character area)
you'll get the very strange 1:1 mapping of the (cp437) graphics card
glyphs.
I'm pretty sure that the 1:1 mapping should only affect strict ASCII
code characters, i.e. chars < 128.
The patch limits the mapping as it probably was meant anyway.
Signed-off-by: Ingo Brueckl <ib@wupperonline.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Egmont Koblinger <egmont@uhulinux.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Problem 1 (see patch below):
vc_tab_stop is declared as an array of 8 unsigned ints in struct
vc_data in include/linux/console_struct.h .
In drivers/char/vt.c only 5 of these 8 unsigned ints get initialized
leading to unintended tabulator placement on displays with more than
160 columns text.
Problem 2 (open):
Upcoming displays will have more than 256 columns of text leading to
invalid memory access in drivers/char/vt.c during tabulator
calculations:
if (vc->vc_tab_stop[vc->vc_x >> 5] & (1 << (vc->vc_x & 31)))
break;
Signed-off-by: Wolfgang Kroworsch <wolfgang@kroworsch.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
People can use the real name an an index into MAINTAINERS to find the
current email address.
Signed-off-by: Francois Cami <francois.cami@free.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit c9e587abfd, and the
subsequent commits that fixed it up:
- afa9b649 "fbcon: prevent cursor disappearance after switching to 512
character font"
- d850a2fa "vt/fbcon: fix background color on line feed"
- 7fe3915a "vt/fbcon: update scrl_erase_char after 256/512-glyph font
switch"
by request of Alan Cox. Quoth Alan:
"Unfortunately it's wrong and its been causing breakages because
various apps like ncurses expect our previous (and correct)
behaviour."
Alexander sent out a similar patch.
Requested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Tested-by: Jan Engelhardt <jengelh@medozas.de>
Cc: Alexander V. Lukyanov <lav@netis.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Carry on pushing code out of tty_io when it belongs to other drivers. I'm
not 100% happy with some of this and it will be worth revisiting some of the
exports later when the restructuring work is done.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Right now there are various drivers that try to use tty->count to know when
they get the final close. Aristeau Rozanski showed while debugging the vt
sysfs race that this isn't entirely safe.
Instead of driver side tricks to work around this introduce a shutdown which
is called when the tty is being destructed. This also means that the shutdown
method is tied into the refcounting.
Use this to rework the console close/sysfs logic.
Remove lots of special case code from the tty core code. The pty code can now
have a shutdown() method that replaces the special case hackery in the tree
free up paths.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For hysterical raisins the vt layer drops and retakes locks in the write
method. This is a left over from the days when user/kernel data was passed
directly to the tty not pre-buffered.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Right now we have ifdefs and hooks in the core ioctl handler for TIOCLINUX
and then test if its a console. This is brain dead. Instead call the
tioclinux helper from the relevant driver ioctl methods.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This moves it to being a tty operation. That removes special cases and now
also means that resize can be picked up by um and other non vt consoles
which may have a resize operation.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2.6.26 corrected the mutex locking on tty resizing to fix the case where
you could get the tty/vt sizing out of sync. That turns out to have a
deadlock.
The actual fix is really major and I've got it lined up as part of the ops
changes for 2.6.28 so for 2.6.26/2.6.27 it is safer to reintroduce this
ages old minor bug.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vt.c DO_UPDATE macro checks if the console is visible but doesn't check if
the console is blanked.
In fact updating fbcon while the console is blanked is not only
unnecessary but can even cause screen corruption.
Therefore I am adding a simple check on console_blanked in DO_UPDATE.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hold console sem while creating/destroying sysfs files. Serialisation is
so far done by BKL held in tty release_dev and chrdev_open, but no other
locks are held in open path.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Aristeu Rozanski <aris@ruivo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
