Commit Graph

77 Commits

Author SHA1 Message Date
Petr Mladek
55bd53a4eb printk: shrink too long messages
We might want to print at least part of too long messages and add some
warning for debugging purpose.

The question is how long the shrunken message should be.  If we use the
whole buffer, it might get rotated too soon.  Let's try to use only 1/4 of
the buffer for now.

Also shrink the whole dictionary.  We do not want to parse it or break it
in the middle of some pair of values.  It would not cause any real harm
but still.

Signed-off-by: Petr Mladek <pmladek@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:16 -07:00
Petr Mladek
85c8704302 printk: split message size computation
We will want to recompute the message size when shrinking too long
messages.  Let's put the code into separate function.

The side effect of setting "pad_len" is not nice but it is worth removing
the code duplication.  Note that I will probably have one more usage for
this function when handling messages safe way in NMI context.

This patch does not change the existing behavior.

Signed-off-by: Petr Mladek <pmladek@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:16 -07:00
Petr Mladek
f40e4b9f70 printk: ignore too long messages
There was no check for too long messages.  The check for free space always
passed when first_seq and next_seq were equal.  Enough free space was not
guaranteed, though.

log_store() might be called to store messages up to 64kB + 64kB + 16B.
This is sum of maximal text_len, dict_len values, and the size of the
structure printk_log.

On the other hand, the minimal size for the main log buffer currently is
4kB and it is enforced only by Kconfig.

The good news is that the usage looks safe right now.  log_store() is
called only from vprintk_emit() and cont_flush().  Here the "text" part is
always passed via a static buffer and the length is limited to
LOG_LINE_MAX which is 1024.  The "dict" part is NULL in most cases.  The
only exceptions is when vprintk_emit() is called from printk_emit() and
dev_vprintk_emit().  But printk_emit() is currently used only in
devkmsg_writev() and here "dict" is NULL as well.  In dev_vprintk_emit(),
"dict" is limited by the static buffer "hdr" of the size 128 bytes.  It
meas that the current maximal printed text is 1024B + 128B + 16B and it
always fit the log buffer.

But it is only matter of time when someone calls printk_emit() with unsafe
parameters, especially the "dict" one.

This patch adds a check for the free space when the buffer is empty.  It
reuses the already existing log_has_space() function but it has to add an
extra parameter.  It defines whether the buffer is empty.  Note that the
same values of "first_idx" and "next_idx" might also mean that the buffer
is full.

If the buffer is empty, we must respect the current position of the
indexes.  We cannot reset them to the beginning of the buffer.  Otherwise,
the functions reading the buffer would get crazy.

The question is what to do when the message is too long.  This patch uses
the easiest solution and just ignores the problematic message.  Let's do
something better in a followup patch.

Signed-off-by: Petr Mladek <pmladek@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:16 -07:00
Petr Mladek
0a581694ab printk: split code for making free space in the log buffer
The check for free space in the log buffer always passes when "first_seq"
and "next_seq" are equal.  In theory, it might cause writing outside of
the log buffer.

Fortunately, the current usage looks safe because the used "text" and
"dict" buffers are quite limited.  See the second patch for more details.

Anyway, it is better to be on the safe side and add a check.  An easy
solution is done in the 2nd patch and it is improved in the 4th patch.

5th patch fixes the computation of the printed message length.

1st and 3rd patches just do some code refactoring to make the other
patches easier.

This patch (of 5):

There will be needed some fixes in the check for free space.  They will be
easier if the code is moved outside of the quite long log_store()
function.

This patch does not change the existing behavior.

Signed-off-by: Petr Mladek <pmladek@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:16 -07:00
Linus Torvalds
49eb7b0750 TTY/Serial driver patches for 3.16-rc1
Here is the big tty / serial driver pull request for 3.16-rc1.
 
 A variety of different serial driver fixes and updates and additions,
 nothing huge, and no real major core tty changes at all.
 
 All have been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty into next

Pull tty/serial driver updates from Greg KH:
 "Here is the big tty / serial driver pull request for 3.16-rc1.

  A variety of different serial driver fixes and updates and additions,
  nothing huge, and no real major core tty changes at all.

  All have been in linux-next for a while"

* tag 'tty-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (84 commits)
  Revert "serial: imx: remove the DMA wait queue"
  serial: kgdb_nmi: Improve console integration with KDB I/O
  serial: kgdb_nmi: Switch from tasklets to real timers
  serial: kgdb_nmi: Use container_of() to locate private data
  serial: cpm_uart: No LF conversion in put_poll_char()
  serial: sirf: Fix compilation failure
  console: Remove superfluous readonly check
  console: Use explicit pointer type for vc_uni_pagedir* fields
  vgacon: Fix & cleanup refcounting
  ARM: tty: Move HVC DCC assembly to arch/arm
  tty/hvc/hvc_console: Fix wakeup of HVC thread on hvc_kick()
  drivers/tty/n_hdlc.c: replace kmalloc/memset by kzalloc
  vt: emulate 8- and 24-bit colour codes.
  printk/of_serial: fix serial console cessation part way through boot.
  serial: 8250_dma: check the result of TX buffer mapping
  serial: uart: add hw flow control support configuration
  tty/serial: at91: add interrupts for modem control lines
  tty/serial: at91: use mctrl_gpio helpers
  tty/serial: Add GPIOLIB helpers for controlling modem lines
  ARM: at91: gpio: implement get_direction
  ...
2014-06-03 09:01:02 -07:00
Stephen Chivers
7fa21dd8bd printk/of_serial: fix serial console cessation part way through boot.
Commit 5f5c9ae56c
"serial_core: Unregister console in uart_remove_one_port()"
fixed a crash where a serial port was removed but
not deregistered as a console.

There is a side effect of that commit for platforms having serial consoles
and of_serial configured (CONFIG_SERIAL_OF_PLATFORM). The serial console
is disabled midway through the boot process.

This cessation of the serial console affects PowerPC computers
such as the MVME5100 and SAM440EP.

The sequence is:

	bootconsole [udbg0] enabled
	....
	serial8250/16550 driver initialises and registers its UARTS,
	one of these is the serial console.
	console [ttyS0] enabled
	....
	of_serial probes "platform" devices, registering them as it goes.
	One of these is the serial console.
	console [ttyS0] disabled.

The disabling of the serial console is due to:

	a.  unregister_console in printk not clearing the
	    CONS_ENABLED bit in the console flags,
	    even though it has announced that the console is disabled; and

	b.  of_platform_serial_probe in of_serial not setting the port type
	    before it registers with serial8250_register_8250_port.

This patch ensures that the serial console is re-enabled when of_serial
registers a serial port that corresponds to the designated console.

Signed-off-by: Stephen Chivers <schivers@csc.com>
Tested-by: Stephen Chivers <schivers@csc.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [unregister_console]
Cc: stable <stable@vger.kernel.org> # 3.15

===
The above failure was identified in Linux-3.15-rc2.

Tested using MVME5100 and SAM440EP PowerPC computers with
kernels built from Linux-3.15-rc5 and tty-next.

The continued operation of the serial console is vital for computers
such as the MVME5100 as that Single Board Computer does not
have any grapical/display hardware.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 13:07:27 -07:00
Andi Kleen
722a9f9299 asmlinkage: Add explicit __visible to drivers/*, lib/*, kernel/*
As requested by Linus add explicit __visible to the asmlinkage users.
This marks functions visible to assembler.

Tree sweep for rest of tree.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1398984278-29319-4-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-05 16:07:46 -07:00
Jane Li
72581487a6 printk: fix one circular lockdep warning about console_lock
Fix a warning about possible circular locking dependency.

If do in following sequence:

    enter suspend ->  resume ->  plug-out CPUx (echo 0 > cpux/online)

lockdep will show warning as following:

  ======================================================
  [ INFO: possible circular locking dependency detected ]
  3.10.0 #2 Tainted: G           O
  -------------------------------------------------------
  sh/1271 is trying to acquire lock:
  (console_lock){+.+.+.}, at: console_cpu_notify+0x20/0x2c
  but task is already holding lock:
  (cpu_hotplug.lock){+.+.+.}, at: cpu_hotplug_begin+0x2c/0x58
  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:
  -> #2 (cpu_hotplug.lock){+.+.+.}:
    lock_acquire+0x98/0x12c
    mutex_lock_nested+0x50/0x3d8
    cpu_hotplug_begin+0x2c/0x58
    _cpu_up+0x24/0x154
    cpu_up+0x64/0x84
    smp_init+0x9c/0xd4
    kernel_init_freeable+0x78/0x1c8
    kernel_init+0x8/0xe4
    ret_from_fork+0x14/0x2c

  -> #1 (cpu_add_remove_lock){+.+.+.}:
    lock_acquire+0x98/0x12c
    mutex_lock_nested+0x50/0x3d8
    disable_nonboot_cpus+0x8/0xe8
    suspend_devices_and_enter+0x214/0x448
    pm_suspend+0x1e4/0x284
    try_to_suspend+0xa4/0xbc
    process_one_work+0x1c4/0x4fc
    worker_thread+0x138/0x37c
    kthread+0xa4/0xb0
    ret_from_fork+0x14/0x2c

  -> #0 (console_lock){+.+.+.}:
    __lock_acquire+0x1b38/0x1b80
    lock_acquire+0x98/0x12c
    console_lock+0x54/0x68
    console_cpu_notify+0x20/0x2c
    notifier_call_chain+0x44/0x84
    __cpu_notify+0x2c/0x48
    cpu_notify_nofail+0x8/0x14
    _cpu_down+0xf4/0x258
    cpu_down+0x24/0x40
    store_online+0x30/0x74
    dev_attr_store+0x18/0x24
    sysfs_write_file+0x16c/0x19c
    vfs_write+0xb4/0x190
    SyS_write+0x3c/0x70
    ret_fast_syscall+0x0/0x48

  Chain exists of:
     console_lock --> cpu_add_remove_lock --> cpu_hotplug.lock

  Possible unsafe locking scenario:
         CPU0                    CPU1
         ----                    ----
  lock(cpu_hotplug.lock);
                                 lock(cpu_add_remove_lock);
                                 lock(cpu_hotplug.lock);
  lock(console_lock);
    *** DEADLOCK ***

There are three locks involved in two sequence:
a) pm suspend:
	console_lock (@suspend_console())
	cpu_add_remove_lock (@disable_nonboot_cpus())
	cpu_hotplug.lock (@_cpu_down())
b) Plug-out CPUx:
	cpu_add_remove_lock (@(cpu_down())
	cpu_hotplug.lock (@_cpu_down())
	console_lock (@console_cpu_notify()) => Lockdeps prints warning log.

There should be not real deadlock, as flag of console_suspended can
protect this.

Although console_suspend() releases console_sem, it doesn't tell lockdep
about it.  That results in the lockdep warning about circular locking
when doing the following: enter suspend -> resume -> plug-out CPUx (echo
0 > cpux/online)

Fix the problem by telling lockdep we actually released the semaphore in
console_suspend() and acquired it again in console_resume().

Signed-off-by: Jane Li <jiel@marvell.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:21:08 -07:00
Petr Mladek
fce6e0338a printk: do not compute the size of the message twice
This is just a tiny optimization.  It removes duplicate computation of
the message size.

Signed-off-by: Petr Mladek <pmladek@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:21:07 -07:00
Petr Mladek
39b25109b4 printk: use also the last bytes in the ring buffer
It seems that we have newer used the last byte in the ring buffer.  In
fact, we have newer used the last 4 bytes because of padding.

First problem is in the check for free space.  The exact number of free
bytes is enough to store the length of data.

Second problem is in the check where the ring buffer is rotated.  The
left side counts the first unused index.  It is unused, so it might be
the same as the size of the buffer.

Note that the first problem has to be fixed together with the second
one.  Otherwise, the buffer is rotated even when there is enough space
on the end of the buffer.  Then the beginning of the buffer is rewritten
and valid entries get corrupted.

Signed-off-by: Petr Mladek <pmladek@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:21:07 -07:00
Petr Mladek
e8c42d36ab printk: add comment about tricky check for text buffer size
There is no check for potential "text_len" overflow.  It is not needed
because only valid level is detected.  It took me some time to
understand why.  It would deserve a comment ;-)

Signed-off-by: Petr Mladek <pmladek@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:21:07 -07:00
Petr Mladek
c64730b26f printk: remove obsolete check for log level "c"
The kernel log level "c" was removed in commit 61e99ab8e3 ("printk:
remove the now unnecessary "C" annotation for KERN_CONT").  It is no
longer detected in printk_get_level().  Hence we do not need to check it
in vprintk_emit.

Signed-off-by: Petr Mladek <pmladek@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:21:07 -07:00
Linus Torvalds
e4178d809f printk: fix syslog() overflowing user buffer
This is not a buffer overflow in the traditional sense: we don't
overflow any *kernel* buffers, but we do mis-count the amount of data we
copy back to user space for the SYSLOG_ACTION_READ_ALL case.

In particular, if the user buffer is too small to hold everything, and
*if* there is a continuation line at just the right place, we can end up
giving the user more data than he asked for.

The reason is that we first count up the number of bytes all the log
records contains, then we walk the records again until we've skipped the
records at the beginning that won't fit, and then we walk the rest of
the records and copy them to the user space buffer.

And in between that "skip the initial records that won't fit" and the
"copy the records that *will* fit to user space", we reset the 'prev'
variable that contained the record information for the last record not
copied.  That meant that when we started copying to user space, we now
had a different character count than what we had originally calculated
in the first record walk-through.

The fix is to simply not clear the 'prev' flags value (in both cases
where we had the same logic: syslog_print_all and kmsg_dump_get_buffer:
the latter is used for pstore-like dumping)

Reported-and-tested-by: Debabrata Banerjee <dbanerje@akamai.com>
Acked-by: Kay Sievers <kay@vrfy.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-17 12:24:45 -08:00
Arun KS
1d3fa37034 printk: flush conflicting continuation line
An earlier newline was missing and current print is from different task.
In this scenario flush the continuation line and store this line
seperatly.

This patch fix the below scenario of timestamp interleaving,
   [   28.154370 ] read_word_reg : reg[0x 3], reg[0x 4]  data [0x 642]
   [   28.155428 ] uart disconnect
   [   31.947341 ] dvfs[cpufreq.c<275>]:plug-in cpu<1> done
   [   28.155445 ] UART detached : send switch state 201
   [   32.014112 ] read_reg : reg[0x 3] data[0x21]

[akpm@linux-foundation.org: simplify and condense the code]
Signed-off-by: Arun KS <getarunks@gmail.com>
Signed-off-by: Arun KS <arun.ks@broadcom.com>
Cc: Joe Perches <joe@perches.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:36:56 -08:00
Santosh Shilimkar
9da791dfab kernel/printk/printk.c: use memblock apis for early memory allocations
Switch to memblock interfaces for early memory allocator instead of
bootmem allocator.  No functional change in beahvior than what it is in
current code from bootmem users points of view.

Archs already converted to NO_BOOTMEM now directly use memblock
interfaces instead of bootmem wrappers build on top of memblock.  And
the archs which still uses bootmem, these new apis just fallback to
exiting bootmem APIs.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21 16:19:47 -08:00
Dirk Gouders
4c1ace6408 printk.c: comments should refer to /proc/vmcore instead of /proc/vmcoreinfo
In one of those comments a typo was fixed, too.

Signed-off-by: Dirk Gouders <dirk@gouders.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:14 +09:00
Dave Young
29e9d22559 kernel/printk/printk.c: enable boot delay for earlyprintk
boot_delay does not work for earlyprintk because the kernel cmdline
parsing is late.

Change to use early_param so early kernel messages can also be delayed.

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:14 +09:00
Andrew Morton
27083baca5 kernel/printk/printk.c: convert to pr_foo()
It was half-and-half.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:14 +09:00
Kees Cook
6b80239447 printk: report console names during cut-over
This reports the names of consoles as they're being disabled to help
identify which is which during cut-over.  Helps answer the question
"which boot console actually got activated?" once the regular console is
running, mostly when debugging boot console failures.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:13 +09:00
Linus Torvalds
2f01ea908b TTY/Serial driver patches for 3.12-rc1
Here's the big tty/serial driver pull request for 3.12-rc1.
 
 Lots of n_tty reworks to resolve some very long-standing issues, removing the
 3-4 different locks that were taken for every character.  This code has been
 beaten on for a long time in linux-next with no reported regressions.
 
 Other than that, a range of serial and tty driver updates and revisions.  Full
 details in the shortlog.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver patches from Greg KH:
 "Here's the big tty/serial driver pull request for 3.12-rc1.

  Lots of n_tty reworks to resolve some very long-standing issues,
  removing the 3-4 different locks that were taken for every character.
  This code has been beaten on for a long time in linux-next with no
  reported regressions.

  Other than that, a range of serial and tty driver updates and
  revisions.  Full details in the shortlog"

* tag 'tty-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (226 commits)
  hvc_xen: Remove unnecessary __GFP_ZERO from kzalloc
  serial: imx: initialize the local variable
  tty: ar933x_uart: add device tree support and binding documentation
  tty: ar933x_uart: allow to build the driver as a module
  ARM: dts: msm: Update uartdm compatible strings
  devicetree: serial: Document msm_serial bindings
  serial: unify serial bindings into a single dir
  serial: fsl-imx-uart: Cleanup duplicate device tree binding
  tty: ar933x_uart: use config_enabled() macro to clean up ifdefs
  tty: ar933x_uart: remove superfluous assignment of ar933x_uart_driver.nr
  tty: ar933x_uart: use the clk API to get the uart clock
  tty: serial: cpm_uart: Adding proper request of GPIO used by cpm_uart driver
  serial: sirf: fix the amount of serial ports
  serial: sirf: define macro for some magic numbers of USP
  serial: icom: move array overflow checks earlier
  TTY: amiserial, remove unnecessary platform_set_drvdata()
  serial: st-asc: remove unnecessary platform_set_drvdata()
  msm_serial: Send more than 1 character on the console w/ UARTDM
  msm_serial: Add support for non-GSBI UARTDM devices
  msm_serial: Switch clock consumer strings and simplify code
  ...
2013-09-03 11:38:36 -07:00
Steven Rostedt
2cfe6c4ac7 printk: Fix return of braille_register_console()
Some of my configs I test with have CONFIG_A11Y_BRAILLE_CONSOLE set.
When I started testing against v3.11-rc4 my console went bonkers.  Using
ktest to bisect the issue, it came down to:

commit bbeddf52a "printk: move braille console support into separate
braille.[ch] files"

Looking into the patch I found the problem.  It's with the return of
braille_register_console().  As anything other than NULL is considered a
failure.

But for those of us that have CONFIG_A11Y_BRAILLE_CONSOLE set but do not
define a "brl" or "brl=" on the command line, we still may want a
console that those with sight can still use.

Return NULL (success) if "brl" or "brl=" is not on the console line.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-06 13:18:12 -07:00
Andreas Bießmann
16cf48a6d3 register_console: prevent adding the same console twice
This patch guards the console_drivers list to be corrupted. The
for_each_console() macro insist on a strictly forward list ended by NULL:

 con0->next->con1->next->NULL

Without this patch it may happen easily to destroy this list for example by
adding 'earlyprintk' twice, especially on embedded devices where the early
console is often a single static instance.  This will result in the following
list:

 con0->next->con0

This in turn will result in an endless loop in console_unlock() later on by
printing the first __log_buf line endlessly.

Signed-off-by: Andreas Bießmann <andreas@biessmann.de>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-05 15:06:46 +08:00
Joe Perches
62e32ac350 printk: rename struct log to struct printk_log
Rename the struct to enable moving portions of
printk.c to separate files.

The rename changes output of /proc/vmcoreinfo.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-31 14:41:03 -07:00
Joe Perches
23475408c6 printk: use pointer for console_cmdline indexing
Make the code a bit more compact by always using a pointer for the active
console_cmdline.

Move overly indented code to correct indent level.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-31 14:41:03 -07:00
Joe Perches
bbeddf52ad printk: move braille console support into separate braille.[ch] files
Create files with prototypes and static inlines for braille support.  Make
braille_console functions return 1 on success.

Corrected CONFIG_A11Y_BRAILLE_CONSOLE=n _braille_console_setup
return value to NULL.

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-31 14:41:03 -07:00
Joe Perches
d197c43d04 printk: add console_cmdline.h
Add an include file for the console_cmdline struct so that the braille
console driver can be separated.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-31 14:41:03 -07:00
Joe Perches
b9ee979e9d printk: move to separate directory for easier modification
Make it easier to break up printk into bite-sized chunks.

Remove printk path/filename from comment.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-31 14:41:03 -07:00