Steven Rostedt 261842b7c9 tracing: add same level recursion detection ... The tracing infrastructure allows for recursion. That is, an interrupt may interrupt the act of tracing an event, and that interrupt may very well perform its own trace. This is a recursive trace, and is fine to do. The problem arises when there is a bug, and the utility doing the trace calls something that recurses back into the tracer. This recursion is not caused by an external event like an interrupt, but by code that is not expected to recurse. The result could be a lockup. This patch adds a bitmask to the task structure that keeps track of the trace recursion. To find the interrupt depth, the following algorithm is used: level = hardirq_count() + softirq_count() + in_nmi; Here, level will be the depth of interrutps and softirqs, and even handles the nmi. Then the corresponding bit is set in the recursion bitmask. If the bit was already set, we know we had a recursion at the same level and we warn about it and fail the writing to the buffer. After the data has been committed to the buffer, we clear the bit. No atomics are needed. The only races are with interrupts and they reset the bitmask before returning anywy. [ Impact: detect same irq level trace recursion ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>		2009-04-17 16:21:32 -04:00
..
irq	tracing/events: move trace point headers into include/trace/events	2009-04-14 22:05:43 -04:00
power	PM/Hibernate: Wait for SCSI devices scan to complete during resume	2009-04-13 11:37:07 -07:00
time	Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-03-26 16:05:42 -07:00
trace	tracing: add same level recursion detection	2009-04-17 16:21:32 -04:00
.gitignore
acct.c	[CVE-2009-0029] System call wrappers part 04	2009-01-14 14:15:19 +01:00
async.c	async: remove the temporary (2.6.29) "async is off by default" code	2009-03-28 13:05:30 -07:00
audit.c	Audit: remove spaces from audit_log_d_path	2009-04-05 13:49:04 -04:00
audit.h
audit_tree.c	audit: incorrect ref counting in audit tree tag_chunk	2009-04-05 13:48:26 -04:00
auditfilter.c	make the e->rule.xxx shorter in kernel auditfilter.c	2009-04-05 13:40:33 -04:00
auditsc.c	Audit: remove spaces from audit_log_d_path	2009-04-05 13:49:04 -04:00
backtracetest.c
bounds.c
capability.c	[CVE-2009-0029] System call wrappers part 04	2009-01-14 14:15:19 +01:00
cgroup.c	memcg: fix OOM killer under memcg	2009-04-02 19:04:55 -07:00
cgroup_debug.c	debug cgroup: remove unneeded cgroup_lock	2009-04-02 19:04:54 -07:00
cgroup_freezer.c
compat.c	Allow times and time system calls to return small negative values	2009-01-06 15:59:13 -08:00
configs.c
cpu.c	cpumask: use set_cpu_active in init/main.c	2009-03-30 22:05:12 +10:30
cpuset.c	cpusets: prevent PF_THREAD_BOUND tasks from attaching to non-root cpusets	2009-04-02 19:04:57 -07:00
cred-internals.h
cred.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6	2009-01-09 13:59:25 -08:00
delayacct.c
dma-coherent.c	dma-coherent: Restore dma_alloc_from_coherent() large alloc fall back policy.	2009-01-21 18:51:53 +09:00
dma.c
exec_domain.c	Get rid of indirect include of fs_struct.h	2009-03-31 23:00:27 -04:00
exit.c	tracing/events: move trace point headers into include/trace/events	2009-04-14 22:05:43 -04:00
extable.c	Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-04-05 11:04:19 -07:00
fork.c	tracing/events: move trace point headers into include/trace/events	2009-04-14 22:05:43 -04:00
freezer.c
futex.c	futex: comment requeue key reference semantics	2009-04-02 23:39:53 +02:00
futex_compat.c
hrtimer.c	hrtimer: fix rq->lock inversion (again)	2009-03-31 14:52:52 +02:00
hung_task.c	softlockup: ensure the task has been switched out once	2009-02-11 11:04:16 +01:00
itimer.c	timers: split process wide cpu clocks/timers	2009-02-05 13:04:33 +01:00
kallsyms.c	Ksplice: Add functions for walking kallsyms symbols	2009-03-31 13:05:32 +10:30
Kconfig.freezer
Kconfig.hz
Kconfig.preempt
kexec.c	kexec: vmcoreinfo_data[] can become static	2009-04-02 19:05:04 -07:00
kfifo.c
kgdb.c
kmod.c	module: create a request_module_nowait()	2009-03-31 13:05:35 +10:30
kprobes.c	kprobes: support per-kprobe disabling	2009-04-07 08:31:08 -07:00
ksysfs.c
kthread.c	tracing/events: move trace point headers into include/trace/events	2009-04-14 22:05:43 -04:00
latencytop.c	sched, latencytop: incorporate review feedback from Andrew Morton	2009-02-11 10:18:04 +01:00
lockdep.c	tracing/events: move trace point headers into include/trace/events	2009-04-14 22:05:43 -04:00
lockdep_internals.h	lockdep: get_user_chars() redo	2009-02-14 23:28:22 +01:00
lockdep_proc.c	lockstat: warn about disabled lock debugging	2009-02-14 23:28:28 +01:00
lockdep_states.h	lockdep: move state bit definitions around	2009-02-14 23:27:59 +01:00
Makefile	Merge branch 'linus' into core/softlockup	2009-04-07 11:15:40 +02:00
marker.c
module.c	ftrace: use module notifier for function tracer	2009-04-17 16:59:15 +02:00
mutex-debug.c	mutex: implement adaptive spinning	2009-01-14 18:09:02 +01:00
mutex-debug.h	mutex: implement adaptive spinning	2009-01-14 18:09:02 +01:00
mutex.c	mutex: have non-spinning mutexes on s390 by default	2009-04-09 19:28:24 +02:00
mutex.h	mutex: implement adaptive spinning	2009-01-14 18:09:02 +01:00
notifier.c
ns_cgroup.c	cgroups: relax ns_can_attach checks to allow attaching to grandchild cgroups	2009-04-02 19:04:53 -07:00
nsproxy.c
panic.c	lockdep: continue lock debugging despite some taints	2009-04-12 16:10:52 +02:00
params.c	param: fix charp parameters set via sysfs	2009-03-31 13:05:30 +10:30
pid.c	pids: refactor vnr/nr_ns helpers to make them safe	2009-04-02 19:05:02 -07:00
pid_namespace.c	signals: zap_pid_ns_process() should use force_sig()	2009-04-02 19:04:58 -07:00
pm_qos_params.c
posix-cpu-timers.c	Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-04-09 10:37:28 -07:00
posix-timers.c	[CVE-2009-0029] System call wrappers part 05	2009-01-14 14:15:20 +01:00
printk.c	Merge branch 'printk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-04-05 10:23:25 -07:00
profile.c	profiling: fix broken profiling regression	2009-02-10 00:50:37 +01:00
ptrace.c	ptrace: some checkpatch fixes	2009-04-08 10:21:44 -07:00
rcuclassic.c	kmemtrace, rcu: fix linux/rcutree.h and linux/rcuclassic.h dependencies	2009-04-03 12:23:02 +02:00
rcupdate.c	rcu: rcu_barrier VS cpu_hotplug: Ensure callbacks in dead cpu are migrated to online cpu	2009-03-31 00:09:37 +02:00
rcupreempt.c	kmemtrace, rcu: fix rcupreempt.c data structure dependencies	2009-04-03 12:23:04 +02:00
rcupreempt_trace.c
rcutorture.c	cpumask: convert rcutorture.c	2009-03-30 22:05:16 +10:30
rcutree.c	kmemtrace, rcu: fix rcu_tree_trace.c data structure dependencies	2009-04-03 12:23:03 +02:00
rcutree.h	kmemtrace, rcu: fix rcu_tree_trace.c data structure dependencies	2009-04-03 12:23:03 +02:00
rcutree_trace.c	kmemtrace, rcu: fix rcu_tree_trace.c data structure dependencies	2009-04-03 12:23:03 +02:00
relay.c	Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-04-05 11:04:19 -07:00
res_counter.c	memcg: memory cgroup resource counters for hierarchy	2009-01-08 08:31:05 -08:00
resource.c	resources: fix parameter name and kernel-doc	2009-01-15 16:39:38 -08:00
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rtmutex_common.h
rwsem.c
sched.c	tracing/events: move trace point headers into include/trace/events	2009-04-14 22:05:43 -04:00
sched_clock.c	Merge branch 'tracing/core-v2' into tracing-for-linus	2009-04-02 00:49:02 +02:00
sched_cpupri.c	sched_rt: don't allocate cpumask in fastpath	2009-04-01 13:24:51 +02:00
sched_cpupri.h	cpumask: remove cpumask_t from core	2009-03-30 22:05:17 +10:30
sched_debug.c	sched: remove unused fields from struct rq	2009-03-24 23:16:51 +01:00
sched_fair.c	Merge branch 'sched/urgent'; commit 'v2.6.29-rc5' into sched/core	2009-02-15 21:15:16 +01:00
sched_features.h	Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-03-30 17:17:35 -07:00
sched_idletask.c
sched_rt.c	Merge commit 'v2.6.30-rc1' into sched/urgent	2009-04-08 17:26:00 +02:00
sched_stats.h	sched: remove unused fields from struct rq	2009-03-24 23:16:51 +01:00
seccomp.c	x86-64: seccomp: fix 32/64 syscall hole	2009-03-02 15:41:30 -08:00
semaphore.c
signal.c	tracing/events: move trace point headers into include/trace/events	2009-04-14 22:05:43 -04:00
slow-work.c	Document the slow work thread pool	2009-04-03 16:42:35 +01:00
smp.c	generic-ipi: eliminate WARN_ON()s during oops/panic	2009-03-13 10:47:34 +01:00
softirq.c	tracing/events: move trace point headers into include/trace/events	2009-04-14 22:05:43 -04:00
softlockup.c	softlockup: decouple hung tasks check from softlockup detection	2009-01-16 14:06:04 +01:00
spinlock.c	Allow rwlocks to re-enable interrupts	2009-04-02 19:05:11 -07:00
srcu.c
stacktrace.c
stop_machine.c	cpumask: remove cpumask_t from core	2009-03-30 22:05:17 +10:30
sys.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6	2009-04-02 21:09:10 -07:00
sys_ni.c	[CVE-2009-0029] Make sys_syslog a conditional system call	2009-01-14 14:15:16 +01:00
sysctl.c	Merge branch 'core/softlockup' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-04-07 14:11:07 -07:00
sysctl_check.c	net: add ARP notify option for devices	2009-02-01 01:04:33 -08:00
taskstats.c
test_kprobes.c	kprobes: add tests for register_kprobes	2009-01-06 15:59:20 -08:00
time.c	[CVE-2009-0029] System call wrappers part 01	2009-01-14 14:15:18 +01:00
timeconst.pl
timer.c	Merge branches 'core-fixes-for-linus', 'irq-fixes-for-linus' and 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-04-09 10:35:30 -07:00
tracepoint.c	tracepoints: dont update zero-sized tracepoint sections	2009-03-18 19:55:00 +01:00
tsacct.c	Fix fixpoint divide exception in acct_update_integrals	2009-03-09 08:13:35 -07:00
uid16.c	[CVE-2009-0029] System call wrappers part 19	2009-01-14 14:15:26 +01:00
up.c	smp_call_function_single(): be slightly less stupid, fix #2	2009-01-12 16:04:37 +01:00
user.c	Merge branch 'master' into next	2009-03-24 10:52:46 +11:00
user_namespace.c	Fix recursive lock in free_uid()/free_user_ns()	2009-02-27 16:26:21 -08:00
utsname.c
utsname_sysctl.c	proc_sysctl: use CONFIG_PROC_SYSCTL around ipc and utsname proc_handlers	2009-04-02 19:05:01 -07:00
wait.c	wait: prevent exclusive waiter starvation	2009-02-05 12:56:48 -08:00
workqueue.c	work_on_cpu(): rewrite it to create a kernel thread on demand	2009-04-09 09:50:37 +09:30