kernel.git/kernel/lockdep.c, branch linux-2.6.33.y

lockdep: Fix lock_is_held() on recursion

2011-06-23T22:28:40Z

commit f2513cde93f0957d5dc6c09bc24b0cccd27d8e1d upstream. The main lock_is_held() user is lockdep_assert_held(), avoid false assertions in lockdep_off() sections by unconditionally reporting the lock is taken. [ the reason this is important is a lockdep_assert_held() in ttwu() which triggers a warning under lockdep_off() as in printk() which can trigger another wakeup and lock up due to spinlock recursion, as reported and heroically debugged by Arne Jansen ] Reported-and-tested-by: Arne Jansen Signed-off-by: Peter Zijlstra Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1307398759.2497.966.camel@laptop Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

lockdep: fix incorrect percpu usage

2010-04-26T14:48:03Z

The mainline kernel as of 2.6.34-rc5 is not affected by this problem because commit 10fad5e46f6c7bdfb01b1a012380a38e3c6ab346 fixed it by refactoring. lockdep fix incorrect percpu usage Should use per_cpu_ptr() to obfuscate the per cpu pointers (RELOC_HIDE is needed for per cpu pointers). git blame points to commit: lockdep.c: commit 8e18257d29238311e82085152741f0c3aa18b74d But it's really just moving the code around. But it's enough to say that the problems appeared before Jul 19 01:48:54 2007, which brings us back to 2.6.23. It should be applied to stable 2.6.23.x to 2.6.33.x (or whichever of these stable branches are still maintained). (tested on 2.6.33.1 x86_64) Signed-off-by: Mathieu Desnoyers CC: Randy Dunlap CC: Eric Dumazet CC: Rusty Russell CC: Peter Zijlstra CC: Tejun Heo CC: Ingo Molnar CC: Andrew Morton CC: Linus Torvalds CC: Greg Kroah-Hartman CC: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

lockdep: Fix check_usage_backwards() error message

2010-01-27T07:34:02Z

Lockdep has found the real bug, but the output doesn't look right to me: > ========================================================= > [ INFO: possible irq lock inversion dependency detected ] > 2.6.33-rc5 #77 > --------------------------------------------------------- > emacs/1609 just changed the state of lock: > (&(&tty->ctrl_lock)->rlock){+.....}, at: [] tty_fasync+0xe8/0x190 > but this lock took another, HARDIRQ-unsafe lock in the past: > (&(&sighand->siglock)->rlock){-.....} "HARDIRQ-unsafe" and "this lock took another" looks wrong, afaics. > ... key at: [] __key.46539+0x0/0x8 > ... acquired at: > [] __lock_acquire+0x1056/0x15a0 > [] lock_acquire+0x9f/0x120 > [] _raw_spin_lock_irqsave+0x52/0x90 > [] __proc_set_tty+0x3e/0x150 > [] tty_open+0x51d/0x5e0 The stack-trace shows that this lock (ctrl_lock) was taken under ->siglock (which is hopefully irq-safe). This is a clear typo in check_usage_backwards() where we tell the print a fancy routine we're forwards. Signed-off-by: Oleg Nesterov Signed-off-by: Peter Zijlstra LKML-Reference: <20100126181641.GA10460@redhat.com> Signed-off-by: Ingo Molnar

locking: Convert __raw_spin* functions to arch_spin*

2009-12-14T22:55:32Z

Name space cleanup. No functional change. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: David S. Miller Acked-by: Ingo Molnar Cc: linux-arch@vger.kernel.org

locking: Rename __RAW_SPIN_LOCK_UNLOCKED to __ARCH_SPIN_LOCK_UNLOCKED

2009-12-14T22:55:32Z

Further name space cleanup. No functional change Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: David S. Miller Acked-by: Ingo Molnar Cc: linux-arch@vger.kernel.org

locking: Convert raw_spinlock to arch_spinlock

2009-12-14T22:55:32Z

The raw_spin* namespace was taken by lockdep for the architecture specific implementations. raw_spin_* would be the ideal name space for the spinlocks which are not converted to sleeping locks in preempt-rt. Linus suggested to convert the raw_ to arch_ locks and cleanup the name space instead of using an artifical name like core_spin, atomic_spin or whatever No functional change. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: David S. Miller Acked-by: Ingo Molnar Cc: linux-arch@vger.kernel.org

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

2009-12-14T17:58:24Z

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (34 commits) m68k: rename global variable vmalloc_end to m68k_vmalloc_end percpu: add missing per_cpu_ptr_to_phys() definition for UP percpu: Fix kdump failure if booted with percpu_alloc=page percpu: make misc percpu symbols unique percpu: make percpu symbols in ia64 unique percpu: make percpu symbols in powerpc unique percpu: make percpu symbols in x86 unique percpu: make percpu symbols in xen unique percpu: make percpu symbols in cpufreq unique percpu: make percpu symbols in oprofile unique percpu: make percpu symbols in tracer unique percpu: make percpu symbols under kernel/ and mm/ unique percpu: remove some sparse warnings percpu: make alloc_percpu() handle array types vmalloc: fix use of non-existent percpu variable in put_cpu_var() this_cpu: Use this_cpu_xx in trace_functions_graph.c this_cpu: Use this_cpu_xx for ftrace this_cpu: Use this_cpu_xx in nmi handling this_cpu: Use this_cpu operations in RCU this_cpu: Use this_cpu ops for VM statistics ... Fix up trivial (famous last words) global per-cpu naming conflicts in arch/x86/kvm/svm.c mm/slab.c

lockdep: Avoid out of bounds array reference in save_trace()

2009-12-10T07:29:33Z

ia64 found this the hard way (because we currently have a stub for save_stack_trace() that does nothing). But it would be a good idea to be cautious in case a real save_stack_trace() bailed out with an error before it set trace->nr_entries. Signed-off-by: Tony Luck Acked-by: Peter Zijlstra Cc: luming.yu@intel.com LKML-Reference: <4b2024d085302c2a2@agluck-desktop.sc.intel.com> Signed-off-by: Ingo Molnar

lockstat: Fix min, max times in /proc/lock_stats

2009-12-06T12:20:00Z

Fix min, max times in /proc/lock_stats (1) When collecting lock hold and wait times, if the current minimum time is zero, it will be replaced by the next time. (2) When aggregating minimum and maximum lock hold and wait times accross cpus, the values are added, instead of selecting the minimum and maximum. Signed-off-by: Frank Rowand Signed-off-by: Peter Zijlstra LKML-Reference: <4B05BBAE.2050005@am.sony.com> Signed-off-by: Ingo Molnar

tracing: Rename 'lockdep' event subsystem into 'lock'

2009-11-13T09:48:27Z

Lockdep events subsystem gathers various locking related events such as a request, release, contention or acquisition of a lock. The name of this event subsystem is a bit of a misnomer since these events are not quite related to lockdep but more generally to locking, ie: these events are not reporting lock dependencies or possible deadlock scenario but pure locking events. Hence this rename. Signed-off-by: Frederic Weisbecker Acked-by: Peter Zijlstra Acked-by: Hitoshi Mitake Cc: Arnaldo Carvalho de Melo Cc: Mike Galbraith Cc: Paul Mackerras Cc: Steven Rostedt Cc: Li Zefan LKML-Reference: <1258103194-843-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar