04 Jul, 2006
40 commits
-
Teach special (recursive) locking code to the lock validator. Has no effect
on non-lockdep kernels.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Create one lock class for all waitqueue locks in the kernel. Has no effect on
non-lockdep kernels.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Teach special (recursive) locking code to the lock validator. Has no effect
on non-lockdep kernels.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Teach special (recursive) locking code to the lock validator. Introduces
double_lock_hb() to unify double- hash-bucket-lock taking.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Teach special (recursive) locking code to the lock validator. Has no effect
on non-lockdep kernels.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Teach special (recursive) locking code to the lock validator. Has no effect
on non-lockdep kernels.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Teach special (dual-initialized) locking code to the lock validator. Has no
effect on non-lockdep kernels.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Cc: Russell King
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Teach special (rwsem-in-irq) locking code to the lock validator. Has no
effect on non-lockdep kernels.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Cc: Russell King
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Enable LOCKDEP_SUPPORT on s390.
Signed-off-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Enable LOCKDEP_SUPPORT on x86_64.
Signed-off-by: Ingo Molnar
Cc: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Enable LOCKDEP_SUPPORT on i386.
Signed-off-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Machine checks on s390 are always enabled (except in the machine check handler
itself). Therefore use lockdep_off()/on() in the machine check handler to
avoid deadlocks in the lock validator.Signed-off-by: Heiko Carstens
Acked-by: Ingo Molnar
Cc: Martin Schwidefsky
Cc: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
On lockdep we have a quite big spinlock_t, so keep the size down.
Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Cc: "David S. Miller"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Make printk()-ing from within the lock validation code safer by using the
lockdep-recursion counter.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Disable SMP alternatives fixups (the patching in of NOPs on 1-CPU systems) if
the lock validator is enabled: there is a binutils section handling bug that
causes corrupted instructions when UP instructions are patched in.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
x86_64 uses spinlocks very early - earlier than start_kernel(). So call
lockdep_init() from the arch setup code.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Cc: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Print all lock-classes on SysRq-D.
Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Offer the following lock validation options:
CONFIG_PROVE_LOCKING
Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Use the lock validator framework to prove mutex locking correctness.
Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Use the lock validator framework to prove spinlock and rwlock locking
correctness.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Use the lock validator framework to prove rwsem locking correctness.
Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Lock validator /proc/lockdep and /proc/lockdep_stats support.
(FIXME: should go into debugfs)Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Lock validator design documentation.
Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
From: Ingo Molnar
lockdep so far only allowed read-recursion for the same lock instance.
This is enough in the overwhelming majority of cases, but a hostap case
triggered and reported by Miles Lane relies on same-class
different-instance recursion. So we relax the restriction on read-lock
recursion.(This change does not allow rwsem read-recursion, which is still
forbidden.)Signed-off-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Do 'make oldconfig' and accept all the defaults for new config options -
reboot into the kernel and if everything goes well it should boot up fine and
you should have /proc/lockdep and /proc/lockdep_stats files.Typically if the lock validator finds some problem it will print out
voluminous debug output that begins with "BUG: ..." and which syslog output
can be used by kernel developers to figure out the precise locking scenario.What does the lock validator do? It "observes" and maps all locking rules as
they occur dynamically (as triggered by the kernel's natural use of spinlocks,
rwlocks, mutexes and rwsems). Whenever the lock validator subsystem detects a
new locking scenario, it validates this new rule against the existing set of
rules. If this new rule is consistent with the existing set of rules then the
new rule is added transparently and the kernel continues as normal. If the
new rule could create a deadlock scenario then this condition is printed out.When determining validity of locking, all possible "deadlock scenarios" are
considered: assuming arbitrary number of CPUs, arbitrary irq context and task
context constellations, running arbitrary combinations of all the existing
locking scenarios. In a typical system this means millions of separate
scenarios. This is why we call it a "locking correctness" validator - for all
rules that are observed the lock validator proves it with mathematical
certainty that a deadlock could not occur (assuming that the lock validator
implementation itself is correct and its internal data structures are not
corrupted by some other kernel subsystem). [see more details and conditionals
of this statement in include/linux/lockdep.h and
Documentation/lockdep-design.txt]Furthermore, this "all possible scenarios" property of the validator also
enables the finding of complex, highly unlikely multi-CPU multi-context races
via single single-context rules, increasing the likelyhood of finding bugs
drastically. In practical terms: the lock validator already found a bug in
the upstream kernel that could only occur on systems with 3 or more CPUs, and
which needed 3 very unlikely code sequences to occur at once on the 3 CPUs.
That bug was found and reported on a single-CPU system (!). So in essence a
race will be found "piecemail-wise", triggering all the necessary components
for the race, without having to reproduce the race scenario itself! In its
short existence the lock validator found and reported many bugs before they
actually caused a real deadlock.To further increase the efficiency of the validator, the mapping is not per
"lock instance", but per "lock-class". For example, all struct inode objects
in the kernel have inode->inotify_mutex. If there are 10,000 inodes cached,
then there are 10,000 lock objects. But ->inotify_mutex is a single "lock
type", and all locking activities that occur against ->inotify_mutex are
"unified" into this single lock-class. The advantage of the lock-class
approach is that all historical ->inotify_mutex uses are mapped into a single
(and as narrow as possible) set of locking rules - regardless of how many
different tasks or inode structures it took to build this set of rules. The
set of rules persist during the lifetime of the kernel.To see the rough magnitude of checking that the lock validator does, here's a
portion of /proc/lockdep_stats, fresh after bootup:lock-classes: 694 [max: 2048]
direct dependencies: 1598 [max: 8192]
indirect dependencies: 17896
all direct dependencies: 16206
dependency chains: 1910 [max: 8192]
in-hardirq chains: 17
in-softirq chains: 105
in-process chains: 1065
stack-trace entries: 38761 [max: 131072]
combined max dependencies: 2033928
hardirq-safe locks: 24
hardirq-unsafe locks: 176
softirq-safe locks: 53
softirq-unsafe locks: 137
irq-safe locks: 59
irq-unsafe locks: 176The lock validator has observed 1598 actual single-thread locking patterns,
and has validated all possible 2033928 distinct locking scenarios.More details about the design of the lock validator can be found in
Documentation/lockdep-design.txt, which can also found at:http://redhat.com/~mingo/lockdep-patches/lockdep-design.txt
[bunk@stusta.de: cleanups]
Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce DEBUG_LOCKING_API_SELFTESTS, which uses the generic lock debugging
code's silent-failure feature to run a matrix of testcases. There are 210
testcases currently:+-----------------------
| Locking API testsuite:
+------------------------------+------+------+------+------+------+------+
| spin |wlock |rlock |mutex | wsem | rsem |
-------------------------------+------+------+------+------+------+------+
A-A deadlock: ok | ok | ok | ok | ok | ok |
A-B-B-A deadlock: ok | ok | ok | ok | ok | ok |
A-B-B-C-C-A deadlock: ok | ok | ok | ok | ok | ok |
A-B-C-A-B-C deadlock: ok | ok | ok | ok | ok | ok |
A-B-B-C-C-D-D-A deadlock: ok | ok | ok | ok | ok | ok |
A-B-C-D-B-D-D-A deadlock: ok | ok | ok | ok | ok | ok |
A-B-C-D-B-C-D-A deadlock: ok | ok | ok | ok | ok | ok |
double unlock: ok | ok | ok | ok | ok | ok |
bad unlock order: ok | ok | ok | ok | ok | ok |
--------------------------------------+------+------+------+------+------+
recursive read-lock: | ok | | ok |
--------------------------------------+------+------+------+------+------+
non-nested unlock: ok | ok | ok | ok |
--------------------------------------+------+------+------+
hard-irqs-on + irq-safe-A/12: ok | ok | ok |
soft-irqs-on + irq-safe-A/12: ok | ok | ok |
hard-irqs-on + irq-safe-A/21: ok | ok | ok |
soft-irqs-on + irq-safe-A/21: ok | ok | ok |
sirq-safe-A => hirqs-on/12: ok | ok | ok |
sirq-safe-A => hirqs-on/21: ok | ok | ok |
hard-safe-A + irqs-on/12: ok | ok | ok |
soft-safe-A + irqs-on/12: ok | ok | ok |
hard-safe-A + irqs-on/21: ok | ok | ok |
soft-safe-A + irqs-on/21: ok | ok | ok |
hard-safe-A + unsafe-B #1/123: ok | ok | ok |
soft-safe-A + unsafe-B #1/123: ok | ok | ok |
hard-safe-A + unsafe-B #1/132: ok | ok | ok |
soft-safe-A + unsafe-B #1/132: ok | ok | ok |
hard-safe-A + unsafe-B #1/213: ok | ok | ok |
soft-safe-A + unsafe-B #1/213: ok | ok | ok |
hard-safe-A + unsafe-B #1/231: ok | ok | ok |
soft-safe-A + unsafe-B #1/231: ok | ok | ok |
hard-safe-A + unsafe-B #1/312: ok | ok | ok |
soft-safe-A + unsafe-B #1/312: ok | ok | ok |
hard-safe-A + unsafe-B #1/321: ok | ok | ok |
soft-safe-A + unsafe-B #1/321: ok | ok | ok |
hard-safe-A + unsafe-B #2/123: ok | ok | ok |
soft-safe-A + unsafe-B #2/123: ok | ok | ok |
hard-safe-A + unsafe-B #2/132: ok | ok | ok |
soft-safe-A + unsafe-B #2/132: ok | ok | ok |
hard-safe-A + unsafe-B #2/213: ok | ok | ok |
soft-safe-A + unsafe-B #2/213: ok | ok | ok |
hard-safe-A + unsafe-B #2/231: ok | ok | ok |
soft-safe-A + unsafe-B #2/231: ok | ok | ok |
hard-safe-A + unsafe-B #2/312: ok | ok | ok |
soft-safe-A + unsafe-B #2/312: ok | ok | ok |
hard-safe-A + unsafe-B #2/321: ok | ok | ok |
soft-safe-A + unsafe-B #2/321: ok | ok | ok |
hard-irq lock-inversion/123: ok | ok | ok |
soft-irq lock-inversion/123: ok | ok | ok |
hard-irq lock-inversion/132: ok | ok | ok |
soft-irq lock-inversion/132: ok | ok | ok |
hard-irq lock-inversion/213: ok | ok | ok |
soft-irq lock-inversion/213: ok | ok | ok |
hard-irq lock-inversion/231: ok | ok | ok |
soft-irq lock-inversion/231: ok | ok | ok |
hard-irq lock-inversion/312: ok | ok | ok |
soft-irq lock-inversion/312: ok | ok | ok |
hard-irq lock-inversion/321: ok | ok | ok |
soft-irq lock-inversion/321: ok | ok | ok |
hard-irq read-recursion/123: ok |
soft-irq read-recursion/123: ok |
hard-irq read-recursion/132: ok |
soft-irq read-recursion/132: ok |
hard-irq read-recursion/213: ok |
soft-irq read-recursion/213: ok |
hard-irq read-recursion/231: ok |
soft-irq read-recursion/231: ok |
hard-irq read-recursion/312: ok |
soft-irq read-recursion/312: ok |
hard-irq read-recursion/321: ok |
soft-irq read-recursion/321: ok |
--------------------------------+-----+----------------
Good, all 210 testcases passed! |
--------------------------------+Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
irqtrace support for s390.
Signed-off-by: Heiko Carstens
Signed-off-by: Ingo Molnar
Cc: Martin Schwidefsky
Cc: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Clean up the x86-64 irqflags.h file:
- macro => inline function transformation
- simplifications
- style fixesSigned-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Cc: Andi Kleen
Cc: Jan Beulich
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add irqflags-tracing support to x86_64.
[akpm@osdl.org: build fix]
Signed-off-by: Ingo Molnar
Cc: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Clean up the x86 irqflags.h file:
- macro => inline function transformation
- simplifications
- style fixesSigned-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add irqflags-tracing support to i386.
Signed-off-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add Documentation/irqflags-tracing.txt.
Signed-off-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Accurate hard-IRQ-flags and softirq-flags state tracing.
This allows us to attach extra functionality to IRQ flags on/off
events (such as trace-on/off).Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
stacktrace interface for s390 as needed by lock validator.
[clg@fr.ibm.com: build fix]
Signed-off-by: Heiko Carstens
Acked-by: Ingo Molnar
Cc: Martin Schwidefsky
Cc: Arjan van de Ven
Signed-off-by: Cedric Le Goater
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Framework to generate and save stacktraces quickly, without printing anything
to the console. x86_64 support.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Cc: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Framework to generate and save stacktraces quickly, without printing anything
to the console. i386 support.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
CONFIG_FRAME_POINTER support for s390.
Signed-off-by: Heiko Carstens
Acked-by: Ingo Molnar
Cc: Martin Schwidefsky
Cc: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Framework to generate and save stacktraces quickly, without printing anything
to the console.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove CONFIG_STACK_BACKTRACE_COLS.
This feature didnt work out: instead of making kernel debugging more
efficient, it produces much harder to read stacktraces! Check out this trace
for example:http://static.flickr.com/47/158326090_35d0129147_b_d.jpg
That backtrace could have been printed much nicer as a one-entry-per-line
thing, taking the same amount of screen real-estate.Plus we remove 30 lines of kernel code as well.
Signed-off-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Document stack frame nesting internals some more.
Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Cc: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
