linux/kernel/lockdep.c, branch v2.6.19

[PATCH] lockdep: fix static keys in module-allocated percpu areas

2006-11-17T19:10:37Z

lockdep got confused by certain locks in modules: INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. Call Trace: [] dump_trace+0xaa/0x3f2 [] show_trace+0x3a/0x60 [] dump_stack+0x15/0x17 [] __lock_acquire+0x724/0x9bb [] lock_acquire+0x4d/0x67 [] rt_spin_lock+0x3d/0x41 [] :ip_conntrack:__ip_ct_refresh_acct+0x131/0x174 [] :ip_conntrack:udp_packet+0xbf/0xcf [] :ip_conntrack:ip_conntrack_in+0x394/0x4a7 [] nf_iterate+0x41/0x7f [] nf_hook_slow+0x64/0xd5 [] ip_rcv+0x24e/0x506 [...] Steven Rostedt found the bug: static_obj() check did not take PERCPU_ENOUGH_ROOM into account, so in-module DEFINE_PER_CPU-area locks were triggering this message. Signed-off-by: Ingo Molnar Signed-off-by: Steven Rostedt Signed-off-by: Linus Torvalds

Merge git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

2006-10-17T15:56:43Z

* git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: fm801-gp - handle errors from pci_enable_device() Input: gameport core - handle errors returned by device_bind_driver() Input: serio core - handle errors returned by device_bind_driver() Lockdep: fix compile error in drivers/input/serio/serio.c Input: serio - add lockdep annotations Lockdep: add lockdep_set_class_and_subclass() and lockdep_set_subclass() Input: atkbd - supress "too many keys" error message Input: i8042 - supress ACK/NAKs when blinking during panic Input: add missing exports to fix modular build

[PATCH] lockdep: increase max allowed recursion depth

2006-10-17T15:18:42Z

In general, lockdep warnings are intended to be non-fatal, so I have put in various practical limits on internal data structure failure modes. We haven't had a /single/ lockdep-internal crash ever since lockdep went upstream [the unwinder crashes are outside of lockdep], and that's largely due to the good internal checks it does. Recursion within the dependency graph is currently limited to 20, that's probably not enough on some many-CPU boxes - this patch doubles it to 40. I have written the lockdep functions to have as small stackframes as possible, so 40 should be OK too. (The practical recursion limit should be somewhere between 100 and 200 entries. If we hit that then I'll change the algorithm to be iteration-based. Graph walking logic is so easy to program via recursion, so i'd like to keep recursion as long as possible.) Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] lockdep: use BUILD_BUG_ON

2006-10-11T18:14:24Z

Signed-off-by: Alexey Dobriyan Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Lockdep: add lockdep_set_class_and_subclass() and lockdep_set_subclass()

2006-10-11T05:45:14Z

This annotation makes it possible to assign a subclass on lock init. This annotation is meant to reduce the _nested() annotations by assigning a default subclass. One could do without this annotation and rely on lockdep_set_class() exclusively, but that would require a manual stack of struct lock_class_key objects. Signed-off-by: Peter Zijlstra Signed-off-by: Dmitry Torokhov

[PATCH] namespaces: utsname: use init_utsname when appropriate

2006-10-02T14:57:21Z

In some places, particularly drivers and __init code, the init utsns is the appropriate one to use. This patch replaces those with a the init_utsname helper. Changes: Removed several uses of init_utsname(). Hope I picked all the right ones in net/ipv4/ipconfig.c. These are now changed to utsname() (the per-process namespace utsname) in the previous patch (2/7) [akpm@osdl.org: CIFS fix] Signed-off-by: Serge E. Hallyn Cc: Kirill Korotaev Cc: "Eric W. Biederman" Cc: Herbert Poetzl Cc: Andrey Savochkin Cc: Serge Hallyn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] lockdep core: improve the lock-chain-hash

2006-09-29T16:18:25Z

With CONFIG_DEBUG_LOCK_ALLOC turned off i was getting sporadic failures in the locking self-test: ------------> | 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 |FAILED| 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 |FAILED| after much debugging it turned out to be caused by accidental chain-hash key collisions. The current hash is: #define iterate_chain_key(key1, key2) \ (((key1) << MAX_LOCKDEP_KEYS_BITS/2) ^ \ ((key1) >> (64-MAX_LOCKDEP_KEYS_BITS/2)) ^ \ (key2)) where MAX_LOCKDEP_KEYS_BITS is 11. This hash is pretty good as it will shift by 5 bits in every iteration, where every new ID 'mixed' into the hash would have up to 11 bits. But because there was a 6 bits overlap between subsequent IDs and their high bits tended to be similar, there was a chance for accidental chain-hash collision for a low number of locks held. the solution is to shift by 11 bits: #define iterate_chain_key(key1, key2) \ (((key1) << MAX_LOCKDEP_KEYS_BITS) ^ \ ((key1) >> (64-MAX_LOCKDEP_KEYS_BITS)) ^ \ (key2)) This keeps the hash perfect up to 5 locks held, but even above that the hash is still good because 11 bits is a relative prime to the total 64 bits, so a complete match will only occur after 64 held locks (which doesnt happen in Linux). Even after 5 locks held, entropy of the 5 IDs mixed into the hash is already good enough so that overlap doesnt generate a colliding hash ID. with this change the false positives went away. Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] lockdep: print kernel version

2006-09-29T16:18:13Z

Lets do the same thing we do for oopses - print out the version in the report. It's an extra line of output though. We could tack it on the end of the INFO: lines, but that screws up Ingo's pretty output. Signed-off-by: Dave Jones Cc: Ingo Molnar Cc: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Avoid recursion in lockdep when stack tracer takes locks

2006-09-26T08:52:34Z

The new dwarf2 unwinder needs to take locks to do backtraces inside modules. This patch makes sure lockdep which calls stacktrace is not reentered. Thanks to Ingo for suggesting this simpler approach. Cc: mingo@elte.hu Signed-off-by: Andi Kleen

[PATCH] x86: Some preparationary cleanup for stack trace

2006-09-26T08:52:34Z

- Remove unused all_contexts parameter No caller used it - Move skip argument into the structure (needed for followon patches) Cc: mingo@elte.hu Signed-off-by: Andi Kleen