* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
futex: fix requeue_pi key imbalance
futex: Fix typo in FUTEX_WAIT/WAKE_BITSET_PRIVATE definitions
rcu: Place root rcu_node structure in separate lockdep class
rcu: Make hot-unplugged CPU relinquish its own RCU callbacks
rcu: Move rcu_barrier() to rcutree
futex: Move exit_pi_state() call to release_mm()
futex: Nullify robust lists after cleanup
futex: Fix locking imbalance
panic: Fix panic message visibility by calling bust_spinlocks(0) before dying
rcu: Replace the rcu_barrier enum with pointer to call_rcu*() function
rcu: Clean up code based on review feedback from Josh Triplett, part 4
rcu: Clean up code based on review feedback from Josh Triplett, part 3
rcu: Fix rcu_lock_map build failure on CONFIG_PROVE_LOCKING=y
rcu: Clean up code to address Ingo's checkpatch feedback
rcu: Clean up code based on review feedback from Josh Triplett, part 2
rcu: Clean up code based on review feedback from Josh Triplett
Commit ffd71da4e3 ("panic: decrease oops_in_progress only after
having done the panic") moved bust_spinlocks(0) to the end of the
function, which in practice is never reached.
As a result console_unblank() is not called, and on some systems
the user may not see the panic message.
Move it back up to before the unblanking.
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1254483680-25578-1-git-send-email-aaro.koskinen@nokia.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If trace_printk_on_oops is set we lose interesting trace information
when the tracer is enabled across oops handling and printing. We want
the trace which might give us information _WHY_ we oopsed.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Ian Campbell noticed that since "Eliminate thousands of warnings with
gcc 3.2 build" (commit 57adc4d2db) all
WARN_ON()'s currently appear to come from warn_slowpath_null(), eg:
WARNING: at kernel/softirq.c:143 warn_slowpath_null+0x1c/0x20()
because now that warn_slowpath_null() is in the call path, the
__builtin_return_address(0) returns that, rather than the place that
caused the warning.
Fix this by splitting up the warn_slowpath_null/fmt cases differently,
using a common helper function, and getting the return address in the
right place. This also happens to avoid the unnecessary stack usage for
the non-stdargs case, and just generally cleans things up.
Make the function name printout use %pS while at it.
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When building with gcc 3.2 I get thousands of warnings such as
include/linux/gfp.h: In function `allocflags_to_migratetype':
include/linux/gfp.h:105: warning: null format string
due to passing a NULL format string to warn_slowpath() in
#define __WARN() warn_slowpath(__FILE__, __LINE__, NULL)
Split this case out into a separate call. This also shrinks the kernel
slightly:
text data bss dec hex filename
4802274 707668 712704 6222646 5ef336 vmlinux
text data bss dec hex filename
4799027 703572 712704 6215303 5ed687 vmlinux
due to removeing one argument from the commonly-called __WARN().
[akpm@linux-foundation.org: reduce scope of `empty']
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andi Kleen reported this message triggering on non-lockdep kernels:
Disabling lockdep due to kernel taint
Clarify the message to say 'lock debugging' - debug_locks_off()
turns off all things lock debugging, not just lockdep.
[ Impact: change kernel warning message text ]
Reported-by: Andi Kleen <andi@firstfloor.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: broaden lockdep checks
Lockdep is disabled after any kernel taints. This might be convenient
to ignore bad locking issues which sources come from outside the kernel
tree. Nevertheless, it might be a frustrating experience for the
staging developers or those who experience a warning but are focused
on another things that require lockdep.
The v2 of this patch simply don't disable anymore lockdep in case
of TAINT_CRAP and TAINT_WARN events.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: LTP <ltp-list@lists.sourceforge.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg KH <gregkh@suse.de>
LKML-Reference: <1239412638-6739-2-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: provide useful missing info for developers
Kernel taint can occur in several situations such as warnings,
load of prorietary or staging modules, bad page, etc...
But when such taint happens, a developer might still be working on
the kernel, expecting that lockdep is still enabled. But a taint
disables lockdep without ever warning about it.
Such a kernel behaviour doesn't really help for kernel development.
This patch adds this missing warning.
Since the taint is done most of the time after the main message that
explain the real source issue, it seems safe to warn about it inside
add_taint() so that it appears at last, without hurting the main
information.
v2: Use a generic helper to disable lockdep instead of an
open coded xchg().
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1239412638-6739-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, no code changed
Clean up kernel/panic.c some more and make it more consistent.
LKML-Reference: <49B91A7E.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, no code changed
Remove an ugly #ifdef CONFIG_SMP from panic(), by providing
an smp_send_stop() wrapper on UP too.
LKML-Reference: <49B91A7E.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: eliminate secondary warnings during panic()
We can panic() in a number of difficult, atomic contexts, hence
we use bust_spinlocks(1) in panic() to increase oops_in_progress,
which prevents various debug checks we have in place.
But in practice this protection only covers the first few printk's
done by panic() - it does not cover the later attempt to stop all
other CPUs and kexec(). If a secondary warning triggers in one of
those facilities that can make the panic message scroll off.
So do bust_spinlocks(0) only much later in panic(). (which code
is only reached if panic policy is relaxed that it can return
after a warning message)
Reported-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B91A7E.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: no default -fno-stack-protector if stackp is enabled, cleanup
Stackprotector make rules had the following problems.
* cc support test and warning are scattered across makefile and
kernel/panic.c.
* -fno-stack-protector was always added regardless of configuration.
Update such that cc support test and warning are contained in makefile
and -fno-stack-protector is added iff stackp is turned off. While at
it, prepare for 32bit support.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, eliminate code
now that warn_on_slowpath() uses warn_slowpath(...,NULL), we can
eliminate warn_on_slowpath() altogether and use warn_slowpath().
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: extend WARN_ON() output with DMI_PRODUCT_NAME
It's very useful for many low level WARN_ON's to find out which
motherboard has the broken BIOS etc... this patch adds a printk
to the WARN_ON code for this.
On architectures without DMI, gcc should optimize the code out.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, code reduction
warn_slowpath is a superset of warn_on_slowpath; just have
warn_on_slowpath call warn_slowpath with a NULL 3rd argument.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This allows them to be examined and set after boot, plus means they
actually give errors if they are misused (eg. panic=yes).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
It's somewhat unlikely that it happens, but right now a race window
between interrupts or machine checks or oopses could corrupt the tainted
bitmap because it is modified in a non atomic fashion.
Convert the taint variable to an unsigned long and use only atomic bit
operations on it.
Unfortunately this means the intvec sysctl functions cannot be used on it
anymore.
It turned out the taint sysctl handler could actually be simplified a bit
(since it only increases capabilities) so this patch actually removes
code.
[akpm@linux-foundation.org: remove unneeded include]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
