Commit Graph

448731 Commits

Author SHA1 Message Date
Joe Perches
9819cf252a checkpatch: warn on unnecessary void function return statements
void function lines that use a single tab then "return;" are generally
unnecessary.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:20 -07:00
Joe Perches
afc819ab02 checkpatch: prefer kstrto<foo> to sscanf(buf, "%<lhuidx>", &bar);
Use the kstrto<foo> functions in preference to sscanf.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:20 -07:00
Joe Perches
60a55369aa checkpatch: add warning for kmalloc/kzalloc with multiply
Protect against sizeof overflows by preferring kmalloc_array/kcalloc over
kmalloc/kzalloc with a sizeof multiply.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:20 -07:00
Joe Perches
f5ef95b12e checkpatch: warn on #defines ending in semicolon
Using a #define ending in a semicolon is poor style and can lead to
unexpected code paths being executed.

Warn on uses of these #define types:

	#define foo[(...)] bar;
	#define foo[(...)]	\
		bar;

Based on a patch from Borislav Petkov.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:20 -07:00
Joe Perches
2ac73b4f68 checkpatch: make --strict a default for files in drivers/net and net/
Networking files are generally more strictly conformant to linux-kernel
style so make checkpatch more verbose by default for patches to files or
when checking files in these directories.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:20 -07:00
Joe Perches
3f7bac031c checkpatch: always warn on missing blank line after variable declaration block
Make the test system wide, modify the message too.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:19 -07:00
Rob Herring
185d566bcd checkpatch: fix wildcard DT compatible string checking
We attempt to search for compatible strings which use a variable token in
the documented name such as <chip> or <soc>.  While this was attempted to
be handled, it's utterly broken.

The desired forms of matching are:

vendor,<chip>-*
vendor,name<part#>-*

For <chip>, lower case characters and numbers are permitted.  For <part#>,
only numeric values are allowed.

With this change, the number of missing compatible strings reported in
arch/arm/boot/dts is reduced from 1071 to 960.

Reported-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Florian Vaussard <florian.vaussard@epfl.ch>
Cc: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:19 -07:00
Fabian Frederick
6516a46619 kernel/compat.c: use sizeof() instead of sizeof
Fix 4 checkpatch warnings
WARNING: sizeof *tv should be sizeof(*tv)

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:19 -07:00
Fabian Frederick
548bbff981 lib/asn1_decoder.c: kernel-doc warning fix
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:19 -07:00
Fabian Frederick
b3b16d284a lib/atomic64_test.c: convert printk(KERN_INFO to pr_info
Convert printk to current pr_foo() logging functions.

Also add pr_fmt based on KBUILD_MODNAME to avoid repeating prefix.  Prefix
is now "atomic64_test: "

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Luca Barbieri <luca@luca-barbieri.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:19 -07:00
Fabian Frederick
c56ba70331 lib/bug.c: convert printk to pr_foo()
- Coalesce formats

- "WARNING:" prefix unchanged to keep bug format.

- printk(KERN_DEFAULT not converted.

- define pr_fmt without prefix to avoid any default prefix update
  (suggested by Joe Perches).

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:19 -07:00
Fabian Frederick
ce643a30d1 lib/textsearch.c: move EXPORT_SYMBOL after functions
Fix checkpatch warning:
"WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable"

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:19 -07:00
Fabian Frederick
6d6a138f13 lib/nlattr.c: move EXPORT_SYMBOL after functions
Fix some checkpatch warnings:
WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Pablo Neira <pablo@netfilter.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:19 -07:00
Fabian Frederick
54b14f40c5 lib/digsig.c: kernel-doc warning fixes
Small typo and @return: -> Returns ...

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:19 -07:00
Fabian Frederick
38b4fe5fcc lib/crc32.c: remove unnecessary __constant
Use cpu_to_le32 instead of __constant_cpu_to_le32.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:19 -07:00
Fabian Frederick
8e4c0b6848 lib/radix-tree.c: kernel-doc warning fix
index has been removed from __radix_tree_delete_node in 449dd6984d
("mm: keep page cache radix tree nodes in check")

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:18 -07:00
Dan Streetman
b8cfff68ea lib/plist.c: make CONFIG_DEBUG_PI_LIST selectable
Change CONFIG_DEBUG_PI_LIST to be user-selectable, and add a title and
description.  Remove the dependency on DEBUG_RT_MUTEXES since they were
changed to use rbtrees, and there are other users of plists now.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:18 -07:00
Minfei Huang
c75b53af2f lib/btree.c: fix leak of whole btree nodes
I use btree from 3.14-rc2 in my own module.  When the btree module is
removed, a warning arises:

 kmem_cache_destroy btree_node: Slab cache still has objects
 CPU: 13 PID: 9150 Comm: rmmod Tainted: GF          O 3.14.0-rc2 #1
 Hardware name: Inspur NF5270M3/NF5270M3, BIOS CHEETAH_2.1.3 09/10/2013
 Call Trace:
   dump_stack+0x49/0x5d
   kmem_cache_destroy+0xcf/0xe0
   btree_module_exit+0x10/0x12 [btree]
   SyS_delete_module+0x198/0x1f0
   system_call_fastpath+0x16/0x1b

The cause is that it doesn't release the last btree node, when height = 1
and fill = 1.

[akpm@linux-foundation.org: remove unneeded test of NULL]
Signed-off-by: Minfei Huang <huangminfei@ucloud.cn>
Cc: Joern Engel <joern@logfs.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:18 -07:00
Fabian Frederick
3f623eba2a lib/vsprintf.c: fix comparison to bool
Fixing 2 coccinelle warnings:
lib/vsprintf.c:2350:2-9: WARNING: Assignment of bool to 0/1
lib/vsprintf.c:2389:3-10: WARNING: Assignment of bool to 0/1

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:18 -07:00
Fabian Frederick
f8eaf298c8 lib/libcrc32c.c: use PTR_ERR_OR_ZERO
replace IS_ERR/PTR_ERR

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:18 -07:00
Lasse Collin
bf4d064d89 lib/xz: enable all filters by default in Kconfig
This restores the old behavior that existed before 2013-02-22, when
changes were made by 64dbfb444c ("decompressors: drop dependency on
CONFIG_EXPERT") and 5dc49c75a2 ("decompressors: make the default
XZ_DEC_* config match the selected architecture").

Disabling the filters only makes sense on embedded systems.

Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Acked-by: Kyle McMartin <kyle@infradead.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:18 -07:00
Dan Streetman
1812062790 lib/plist.c: replace pr_debug with printk in plist_test()
Replace pr_debug() in lib/plist.c test function plist_test() with
printk(KERN_DEBUG ...).

Without DEBUG defined, pr_debug() is complied out, but the entire
plist_test() function is already inside CONFIG_DEBUG_PI_LIST, so printk
should just be used directly.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:18 -07:00
Lasse Collin
84d517f3e5 lib/xz: add comments for the intentionally missing break statements
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:18 -07:00
Dan Carpenter
0046dd9fed lib/string.c: use the name "C-string" in comments
For strncpy() and friends the source string may or may not have an actual
NUL character at the end.  The documentation is confusing in this because
it specifically mentions that you are passing a "NUL-terminated" string.
Wikipedia says that "C-string" is an alternative name we can use instead.

http://en.wikipedia.org/wiki/Null-terminated_string

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:18 -07:00
Borislav Petkov
a8fe19ebfb kernel/printk: use symbolic defines for console loglevels
... instead of naked numbers.

Stuff in sysrq.c used to set it to 8 which is supposed to mean above
default level so set it to DEBUG instead as we're terminating/killing all
tasks and we want to be verbose there.

Also, correct the check in x86_64_start_kernel which should be >= as
we're clearly issuing the string there for all debug levels, not only
the magical 10.

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Joe Perches <joe@perches.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:17 -07:00
Will Deacon
84b5ec8a9d printk: report dropping of messages from logbuf
If the log ring buffer becomes full, we silently overwrite old messages
with new data.  console_unlock will detect this case and fast-forward the
console_* pointers to skip over the corrupted data, but nothing will be
reported to the user.

This patch hijacks the first valid log message after detecting that we
dropped messages and prefixes it with a note detailing how many messages
were dropped.  For long (~1000 char) messages, this will result in some
truncation of the real message, but given that we're dropping things
anyway, that doesn't seem to be the end of the world.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:17 -07:00
Dan Streetman
6e099f557d Documentation: expand/clarify debug documentation
The pr_debug() and related debug print macros all differ from the normal
pr_XXX() macros, in that the normal ones print unconditionally, while
the debug macros are compiled out unless DEBUG is defined or
CONFIG_DYNAMIC_DEBUG is set.  This isn't obvious, and the only way to
find this out is either to review the actual printk.h code or to read
CodingStyle, and the message there doesn't highlight the fact.

Change Documentation/CodingStyle to clearly indicate that pr_debug() and
related debug printing macros behave differently than all other pr_XXX()
macros, and attempt to clarify when and where the different debug
printing methods might be used.

Add short comment to printk.h above the pr_XXX() macros indicating that
while these macros print unconditionally, pr_debug() does not.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Cc: Joe Perches <joe@perches.com>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:17 -07:00
John Stultz
6d9bcb621b timekeeping: use printk_deferred when holding timekeeping seqlock
Jiri Bohac pointed out that there are rare but potential deadlock
possibilities when calling printk while holding the timekeeping
seqlock.

This is due to printk() triggering console sem wakeup, which can
cause scheduling code to trigger hrtimers which may try to read
the time.

Specifically, as Jiri pointed out, that path is:
  printk
    vprintk_emit
      console_unlock
        up(&console_sem)
          __up
	    wake_up_process
	      try_to_wake_up
	        ttwu_do_activate
		  ttwu_activate
		    activate_task
		      enqueue_task
		        enqueue_task_fair
			  hrtick_update
			    hrtick_start_fair
			      hrtick_start_fair
			        get_time
				  ktime_get
				    --> endless loop on
				    read_seqcount_retry(&timekeeper_seq, ...)

This patch tries to avoid this issue by using printk_deferred (previously
named printk_sched) which should defer printing via a irq_work_queue.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Reported-by: Jiri Bohac <jbohac@suse.cz>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:17 -07:00
John Stultz
c224815dac printk: Add printk_deferred_once
Two of the three prink_deferred uses are really printk_once style
uses, so add a printk_deferred_once macro to simplify those call
sites.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:17 -07:00
John Stultz
aac74dc495 printk: rename printk_sched to printk_deferred
After learning we'll need some sort of deferred printk functionality in
the timekeeping core, Peter suggested we rename the printk_sched function
so it can be reused by needed subsystems.

This only changes the function name. No logic changes.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:17 -07:00
John Stultz
8195460626 printk: disable preemption for printk_sched
An earlier change in -mm (printk: remove separate printk_sched
buffers...), removed the printk_sched irqsave/restore lines since it was
safe for current users.  Since we may be expanding usage of
printk_sched(), disable preepmtion for this function to make it more
generally safe to call.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:17 -07:00
Steven Rostedt
458df9fd48 printk: remove separate printk_sched buffers and use printk buf instead
To prevent deadlocks with doing a printk inside the scheduler,
printk_sched() was created.  The issue is that printk has a console_sem
that it can grab and release.  The release does a wake up if there's a
task pending on the sem, and this wake up grabs the rq locks that is
held in the scheduler.  This leads to a possible deadlock if the wake up
uses the same rq as the one with the rq lock held already.

What printk_sched() does is to save the printk write in a per cpu buffer
and sets the PRINTK_PENDING_SCHED flag.  On a timer tick, if this flag is
set, the printk() is done against the buffer.

There's a couple of issues with this approach.

1) If two printk_sched()s are called before the tick, the second one
   will overwrite the first one.

2) The temporary buffer is 512 bytes and is per cpu.  This is a quite a
   bit of space wasted for something that is seldom used.

In order to remove this, the printk_sched() can use the printk buffer
instead, and delay the console_trylock()/console_unlock() to the queued
work.

Because printk_sched() would then be taking the logbuf_lock, the
logbuf_lock must not be held while doing anything that may call into the
scheduler functions, which includes wake ups.  Unfortunately, printk()
also has a console_sem that it uses, and on release, the up(&console_sem)
may do a wake up of any pending waiters.  This must be avoided while
holding the logbuf_lock.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:17 -07:00
Jan Kara
939f04bec1 printk: enable interrupts before calling console_trylock_for_printk()
We need interrupts disabled when calling console_trylock_for_printk()
only so that cpu id we pass to can_use_console() remains valid (for
other things console_sem provides all the exclusion we need and
deadlocks on console_sem due to interrupts are impossible because we use
down_trylock()).  However if we are rescheduled, we are guaranteed to
run on an online cpu so we can easily just get the cpu id in
can_use_console().

We can lose a bit of performance when we enable interrupts in
vprintk_emit() and then disable them again in console_unlock() but OTOH
it can somewhat reduce interrupt latency caused by console_unlock()
especially since later in the patch series we will want to spin on
console_sem in console_trylock_for_printk().

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:17 -07:00
Jan Kara
bd8d7cf5b8 printk: fix lockdep instrumentation of console_sem
Printk calls mutex_acquire() / mutex_release() by hand to instrument
lockdep about console_sem.  However in some corner cases the
instrumentation is missing.  Fix the problem by creating helper functions
for locking / unlocking console_sem which take care of lockdep
instrumentation as well.

Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Fabio Estevam <festevam@gmail.com>
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-By: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.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
Jan Kara
608873cacb printk: release lockbuf_lock before calling console_trylock_for_printk()
There's no reason to hold lockbuf_lock when entering
console_trylock_for_printk().

The first thing this function does is to call down_trylock(console_sem)
and if that fails it immediately unlocks lockbuf_lock.  So lockbuf_lock
isn't needed for that branch.  When down_trylock() succeeds, the rest of
console_trylock() is OK without lockbuf_lock (it is called without it
from other places), and the only remaining thing in
console_trylock_for_printk() is can_use_console() call.  For that call
console_sem is enough (it iterates all consoles and checks CON_ANYTIME
flag).

So we drop logbuf_lock before entering console_trylock_for_printk() which
simplifies the code.

[akpm@linux-foundation.org: fix have_callable_console() comment]
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:16 -07:00
Jan Kara
ca1d432ad8 printk: remove outdated comment
Comment about interesting interlocking between lockbuf_lock and
console_sem is outdated.

It was added in 2002 by commit a880f45a48be during conversion of
console_lock to console_sem + lockbuf_lock.

At that time release_console_sem() (today's equivalent is
console_unlock()) was indeed using lockbuf_lock to avoid races between
trylock on console_sem in printk() and unlock of console_sem.  However
these days the interlocking is gone and the races are avoided by
rechecking logbuf state after releasing console_sem.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:16 -07:00
Petr Mladek
034633ccb2 printk: return really stored message length
I wonder if anyone uses printk return value but it is there and should be
counted correctly.

This patch modifies log_store() to return the number of really stored
bytes from the 'text' part.  Also it handles the return value in
vprintk_emit().

Note that log_store() is used also in cont_flush() but we could ignore the
return value there.  The function works with characters that were already
counted earlier.  In addition, the store could newer fail here because the
length of the printed text is limited by the "cont" buffer and "dict" is
NULL.

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
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
Kirill A. Shutemov
b300a4ea66 kernel/user.c: drop unused field 'files' from user_struct
Nobody seems uses it for a long time. Let's drop it.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
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
Fabian Frederick
b51dbec68c kernel/hung_task.c: convert simple_strtoul to kstrtouint
sysctl_hung_task_panic has been changed to unsigned int.  use kstrtouint
instead of obsolete simple_strtoul

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:15 -07:00
Fabian Frederick
95583e4ab5 kernel/utsname_sysctl.c: replace obsolete __initcall by device_initcall
Also fixes checkpatch warnings on proc_dostring function parameters

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:15 -07:00
Fabian Frederick
616feab753 kernel/reboot.c: convert simple_strtoul to kstrtoint
Replace obsolete function.
kstrtoint is used as reboot_cpu is an integer.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:15 -07:00
Fabian Frederick
6c5a53c670 kernel/res_counter.c: replace simple_strtoull by kstrtoull
[akpm@linux-foundation.org: don't overwrite kstrtoull()'s errno]
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:15 -07:00
Fabian Frederick
cac92ba74f kernel/tracepoint.c: kernel-doc fixes
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:15 -07:00
Fabian Frederick
cf25004069 kernel/stop_machine.c: kernel-doc warning fix
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:15 -07:00
Fabian Frederick
eaa1809b90 kernel/latencytop.c: convert seq_printf to seq_puts
This patch also fixes one function declaration over 80 characters.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:15 -07:00
Fabian Frederick
b9e5db6d2b kernel/exec_domain.c: code clean-up
Fix checkpatch warnings about EXPORT_SYMBOL and return()

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:15 -07:00