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* [PATCH] Fix prctl privilege escalation and suid_dumpable (CVE-2006-2451)Marcel Holtmann2006-07-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on a patch from Ernie Petrides During security research, Red Hat discovered a behavioral flaw in core dump handling. A local user could create a program that would cause a core file to be dumped into a directory they would not normally have permissions to write to. This could lead to a denial of service (disk consumption), or allow the local user to gain root privileges. The prctl() system call should never allow to set "dumpable" to the value 2. Especially not for non-privileged users. This can be split into three cases: 1) running as root -- then core dumps will already be done as root, and so prctl(PR_SET_DUMPABLE, 2) is not useful 2) running as non-root w/setuid-to-root -- this is the debatable case 3) running as non-root w/setuid-to-non-root -- then you definitely do NOT want "dumpable" to get set to 2 because you have the privilege escalation vulnerability With case #2, the only potential usefulness is for a program that has designed to run with higher privilege (than the user invoking it) that wants to be able to create root-owned root-validated core dumps. This might be useful as a debugging aid, but would only be safe if the program had done a chdir() to a safe directory. There is no benefit to a production setuid-to-root utility, because it shouldn't be dumping core in the first place. If this is true, then the same debugging aid could also be accomplished with the "suid_dumpable" sysctl. Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: disable lock debugging when kernel state becomes untrustedArjan van de Ven2006-07-10
| | | | | | | | | | | | | | | | | | | | | | | Disable lockdep debugging in two situations where the integrity of the kernel no longer is guaranteed: when oopsing and when hitting a tainting-condition. The goal is to not get weird lockdep traces that don't make sense or are otherwise undebuggable, to not waste time. Lockdep assumes that the previous state it knows about is valid to operate, which is why lockdep turns itself off after the first violation it reports, after that point it can no longer make that assumption. A kernel oops means that the integrity of the kernel compromised; in addition anything lockdep would report is of lesser importance than the oops. All the tainting conditions are of similar integrity-violating nature and also make debugging/diagnosing more difficult. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] remove the tasklist_lock exportChristoph Hellwig2006-07-10
| | | | | | | | | As announced half a year ago this patch will remove the tasklist_lock export. The previous two patches got rid of the remaining modular users. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] uninline init_waitqueue_head()Ingo Molnar2006-07-10
| | | | | | | | | | | | | | | | allyesconfig vmlinux size delta: text data bss dec filename 20736884 6073834 3075176 29885894 vmlinux.before 20721009 6073966 3075176 29870151 vmlinux.after ~18 bytes per callsite, 15K of text size (~0.1%) saved. (as an added bonus this also removes a lockdep annotation.) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] swsusp: fix panic when signature can't be readLinus Torvalds2006-07-10
| | | | | | | | Do not panic a machine when swsusp signature can't be read. Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] swsusp warning fixAndrew Morton2006-07-10
| | | | | | | | | | | | kernel/power/swap.c: In function 'swsusp_write': kernel/power/swap.c:275: warning: 'start' may be used uninitialized in this function gcc isn't smart enough, so help it. Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] swsusp: do not use memcpy for snapshotting memoryRafael J. Wysocki2006-07-10
| | | | | | | | | | | | | | swsusp should not use memcpy for snapshotting memory, because on some architectures memcpy may increase preempt_count (i386 does this when CONFIG_X86_USE_3DNOW is set). Then, as a result, wrong value of preempt_count is stored in the image. Replace memcpy in copy_data_pages with an open-coded loop. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] adjust clock for lost ticksRoman Zippel2006-07-10
| | | | | | | | | | | | | | A large number of lost ticks can cause an overadjustment of the clock. To compensate for this we look at the current error and the larger the error already is the more careful we are at adjusting the error. As small extra fix reset the error when the clock is set. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Acked-by: john stultz <johnstul@us.ibm.com> Cc: Uwe Bugla <uwe.bugla@gmx.de> Cc: James Bottomley <James.Bottomley@SteelEye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] pi-futex: Validate futex type instead of oopsingThomas Gleixner2006-07-10
| | | | | | | | | | | | Calling futex_lock_pi is called with a reference to a non PI futex and waiters exist already, lookup_pi_state() oopses due to pi_state == NULL. Check this condition and return -EINVAL to userspace. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jakub Jelinek <jakub@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kernel/softirq.c: EXPORT_UNUSED_SYMBOLAdrian Bunk2006-07-10
| | | | | | | | This patch marks an unused export as EXPORT_UNUSED_SYMBOL. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kernel/printk.c: EXPORT_SYMBOL_UNUSEDAdrian Bunk2006-07-10
| | | | | | | | This patch marks unused exports as EXPORT_SYMBOL_UNUSED. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: core, reduce per-lock class-cache sizeIngo Molnar2006-07-10
| | | | | | | | | | | | | | | lockdep_map is embedded into every lock, which blows up data structure sizes all around the kernel. Reduce the class-cache to be for the default class only - that is used in 99.9% of the cases and even if we dont have a class cached, the lookup in the class-hash is lockless. This change reduces the per-lock dep_map overhead by 56 bytes on 64-bit platforms and by 28 bytes on 32-bit platforms. Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: improve debug outputArjan van de Ven2006-07-10
| | | | | | | | | | Make lockdep print which lock is held, in the "kfree() of a live lock" scenario. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Minor cleanup to lockdep.cAndi Kleen2006-07-10
| | | | | | | | | | - Use printk formatting for indentation - Don't leave NTFS in the default event filter Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] small kernel/sched.c cleanupAndreas Mohr2006-07-10
| | | | | | | | | | - constify and optimize stat_nam (thanks to Michael Tokarev!) - spelling and comment fixes Signed-off-by: Andreas Mohr <andi@lisas.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: fix bug in __migrate_task()Peter Williams2006-07-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Problem: In the function __migrate_task(), deactivate_task() followed by activate_task() is used to move the task from one run queue to another. This has two undesirable effects: 1. The task's priority is recalculated. (Nowhere else in the scheduler code is the priority recalculated for a change of CPU.) 2. The task's time stamp is set to the current time. At the very least, this makes the adjustment of the time stamp before the call to deactivate_task() redundant but I believe the problem is more serious as the time stamp now holds the time of the queue change instead of the time at which the task was woken. In addition, unless dest_rq is the same queue as "current" is on the time stamp could be inaccurate due to inter CPU drift. Solution: Replace the call to activate_task() with one to __activate_task(). Signed-off-by: Peter Williams <pwil3058@bigpond.net.au> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreqLinus Torvalds2006-07-04
|\ | | | | | | | | | | | | | | | | * master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq: Move workqueue exports to where the functions are defined. [CPUFREQ] Misc cleanups in ondemand. [CPUFREQ] Make ondemand sampling per CPU and remove the mutex usage in sampling path. [CPUFREQ] Add queue_delayed_work_on() interface for workqueues. [CPUFREQ] Remove slowdown from ondemand sampling path.
| * Move workqueue exports to where the functions are defined.Dave Jones2006-06-30
| | | | | | | | Signed-off-by: Dave Jones <davej@redhat.com>
| * [CPUFREQ] Add queue_delayed_work_on() interface for workqueues.Venkatesh Pallipadi2006-06-30
| | | | | | | | | | | | | | | | Add queue_delayed_work_on() interface for workqueues. Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
* | [PATCH] revert "kthread: convert stop_machine into a kthread"Andrew Morton2006-07-04
| | | | | | | | | | | | | | | | | | | | | | | | | | Jiri reports that the stop_machin kthread conversion caused his machine to hang when suspending. Hyperthreading is apparently involved. I don't see why that would be and I can't reproduce it. Revert to the 2.6.17 code. Cc: "Serge E. Hallyn" <serue@us.ibm.com> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpcLinus Torvalds2006-07-03
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: powerpc: add defconfig for Freescale MPC8349E-mITX board powerpc: Add base support for the Freescale MPC8349E-mITX eval board Documentation: correct values in MPC8548E SEC example node [POWERPC] Actually copy over i8259.c to arch/ppc/syslib this time [POWERPC] Add new interrupt mapping core and change platforms to use it [POWERPC] Copy i8259 code back to arch/ppc [POWERPC] New device-tree interrupt parsing code [POWERPC] Use the genirq framework [PATCH] genirq: Allow fasteoi handler to retrigger disabled interrupts [POWERPC] Update the SWIM3 (powermac) floppy driver [POWERPC] Fix error handling in detecting legacy serial ports [POWERPC] Fix booting on Momentum "Apache" board (a Maple derivative) [POWERPC] Fix various offb and BootX-related issues [POWERPC] Add a default config for 32-bit CHRP machines [POWERPC] fix implicit declaration on cell. [POWERPC] change get_property to return void *
| * | [PATCH] genirq: Allow fasteoi handler to retrigger disabled interruptsBenjamin Herrenschmidt2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the fasteoi handler mark disabled interrupts as pending if they happen anyway. This allow implementation of a delayed disable scheme with the fasteoi handler. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul Mackerras <paulus@samba.org>
* | | [PATCH] sched: cleanup, convert sched.c-internal typedefs to structIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] sched: cleanup, remove task_t, convert to struct task_structIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] sched: clean up fallout of recent changesIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: irqtrace subsystem, move account_system_vtime() calls into ↵Paul Mackerras2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernel/softirq.c At the moment, powerpc and s390 have their own versions of do_softirq which include local_bh_disable() and __local_bh_enable() calls. They end up calling __do_softirq (in kernel/softirq.c) which also does local_bh_disable/enable. Apparently the two levels of disable/enable trigger a warning from some validation code that Ingo is working on, and he would like to see the outer level removed. But to do that, we have to move the account_system_vtime calls that are currently in the arch do_softirq() implementations for powerpc and s390 into the generic __do_softirq() (this is a no-op for other archs because account_system_vtime is defined to be an empty inline function on all other archs). This patch does that. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: annotate on-stack completionsIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | lockdep needs to have the waitqueue lock initialized for on-stack waitqueues implicitly initialized by DECLARE_COMPLETION(). Annotate on-stack completions accordingly. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: annotate enable_in_hardirq()Ingo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make use of local_irq_enable_in_hardirq() API to annotate places that enable hardirqs in hardirq context. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: annotate ->mmap_semIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Teach special (recursive) locking code to the lock validator. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: annotate hrtimer base locksIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Teach special (recursive) locking code to the lock validator. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: annotate scheduler runqueue locksIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Teach per-CPU runqueue locks and recursive locking code to the lock validator. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: annotate timer base locksIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split the per-CPU timer base locks up into separate lock classes, because they are used recursively. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: annotate waitqueuesIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Create one lock class for all waitqueue locks in the kernel. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: annotate genirqIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Teach special (recursive) locking code to the lock validator. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: annotate futexIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: do not recurse in printkIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make printk()-ing from within the lock validation code safer by using the lockdep-recursion counter. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: prove mutex locking correctnessIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | Use the lock validator framework to prove mutex locking correctness. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: prove spinlock rwlock locking correctnessIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the lock validator framework to prove spinlock and rwlock locking correctness. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: prove rwsem locking correctnessIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | Use the lock validator framework to prove rwsem locking correctness. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: procfsIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lock validator /proc/lockdep and /proc/lockdep_stats support. (FIXME: should go into debugfs) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: allow read_lock() recursion of same classIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | From: Ingo Molnar <mingo@elte.hu> 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 <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: coreIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: 176 The 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 <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: irqtrace subsystem, coreIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: stacktrace subsystem, coreIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Framework to generate and save stacktraces quickly, without printing anything to the console. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: locking init debugging improvementIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Locking init improvement: - introduce and use __SPIN_LOCK_UNLOCKED for array initializations, to pass in the name string of locks, used by debugging Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: mutex section binutils workaroundIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Work around weird section nesting build bug causing smp-alternatives failures under certain circumstances. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: better lock debuggingIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Generic lock debugging: - generalized lock debugging framework. For example, a bug in one lock subsystem turns off debugging in all lock subsystems. - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from the mutex/rtmutex debugging code: it caused way too much prototype hackery, and lockdep will give the same information anyway. - ability to do silent tests - check lock freeing in vfree too. - more finegrained debugging options, to allow distributions to turn off more expensive debugging features. There's no separate 'held mutexes' list anymore - but there's a 'held locks' stack within lockdep, which unifies deadlock detection across all lock classes. (this is independent of the lockdep validation stuff - lockdep first checks whether we are holding a lock already) Here are the current debugging options: CONFIG_DEBUG_MUTEXES=y CONFIG_DEBUG_LOCK_ALLOC=y which do: config DEBUG_MUTEXES bool "Mutex debugging, basic checks" config DEBUG_LOCK_ALLOC bool "Detect incorrect freeing of live mutexes" Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: remove mutex deadlock checking codeIngo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | With the lock validator we detect mutex deadlocks (and more), the mutex deadlock checking code is both redundant and slower. So remove it. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: remove DEBUG_BUG_ON()Ingo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | cleanup: remove unused DEBUG_BUG_ON() defines. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] lockdep: rename DEBUG_WARN_ON()Ingo Molnar2006-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | Rename DEBUG_WARN_ON() to the less generic DEBUG_LOCKS_WARN_ON() name, so that it's clear that this is a lock-debugging internal mechanism. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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