Steven Rostedt (Red Hat) b24d443b8f ftrace: Clear REGS_EN and TRAMP_EN flags on disabling record via sysctl ... When /proc/sys/kernel/ftrace_enabled is set to zero, all function tracing is disabled. But the records that represent the functions still hold information about the ftrace_ops that are hooked to them. ftrace_ops may request "REGS" (have a full set of pt_regs passed to the callback), or "TRAMP" (the ops has its own trampoline to use). When the record is updated to represent the state of the ops hooked to it, it sets "REGS_EN" and/or "TRAMP_EN" to state that the callback points to the correct trampoline (REGS has its own trampoline). When ftrace_enabled is set to zero, all ftrace locations are a nop, so they do not point to any trampoline. But the _EN flags are still set. This can cause the accounting to go wrong when ftrace_enabled is cleared and an ops that has a trampoline is registered or unregistered. For example, the following will cause ftrace to crash: # echo function_graph > /sys/kernel/debug/tracing/current_tracer # echo 0 > /proc/sys/kernel/ftrace_enabled # echo nop > /sys/kernel/debug/tracing/current_tracer # echo 1 > /proc/sys/kernel/ftrace_enabled # echo function_graph > /sys/kernel/debug/tracing/current_tracer As function_graph uses a trampoline, when ftrace_enabled is set to zero the updates to the record are not done. When enabling function_graph again, the record will still have the TRAMP_EN flag set, and it will look for an op that has a trampoline other than the function_graph ops, and fail to find one. Cc: stable@vger.kernel.org # 3.17+ Reported-by: Pratyush Anand <panand@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>		2015-03-09 10:46:00 -04:00
..
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2015-01-27 13:55:36 -08:00
configs
debug	debug: prevent entering debug mode on panic/exception.	2015-02-19 12:39:03 -06:00
events	Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-16 14:58:12 -08:00
gcov	kbuild,gcov: simplify kernel/gcov/Makefile more	2015-01-09 17:25:44 +01:00
irq	Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-16 15:20:40 -08:00
livepatch	livepatch: RCU protect struct klp_func all the time when used in klp_ftrace_handler()	2015-02-22 23:02:56 +01:00
locking	locking/rtmutex: Set state back to running on error	2015-03-01 09:45:06 +01:00
power	PM / sleep: Re-implement suspend-to-idle handling	2015-02-13 23:49:36 +01:00
printk	KGDB/KDB New:	2015-02-20 15:13:29 -08:00
rcu	Merge branches 'core-urgent-for-linus' and 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-21 10:36:06 -08:00
sched	Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-21 10:40:02 -08:00
time	Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-21 11:05:22 -08:00
trace	ftrace: Clear REGS_EN and TRAMP_EN flags on disabling record via sysctl	2015-03-09 10:46:00 -04:00
.gitignore
acct.c	new fs_pin killing logics	2015-01-25 23:17:28 -05:00
async.c	kernel/async.c: switch to pr_foo()	2014-10-09 22:26:04 -04:00
audit.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2014-12-30 10:45:47 -08:00
audit.h	audit: replace getname()/putname() hacks with reference counters	2015-01-23 00:23:58 -05:00
audit_tree.c	fsnotify: unify inode and mount marks handling	2014-12-13 12:42:53 -08:00
audit_watch.c
auditfilter.c	Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit	2015-02-11 20:07:47 -08:00
auditsc.c	Merge branch 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2015-02-17 15:27:47 -08:00
backtracetest.c
bounds.c
capability.c
cgroup.c	kernfs: remove KERNFS_STATIC_NAME	2015-02-13 21:21:36 -08:00
cgroup_freezer.c
compat.c	all arches, signal: move restart_block to struct task_struct	2015-02-12 18:54:12 -08:00
configs.c
context_tracking.c	sched: stop the unbound recursion in preempt_schedule_context()	2014-10-28 10:46:05 +01:00
cpu.c	hotplugcpu: Avoid deadlocks by waking active_writer	2015-01-06 11:01:14 -08:00
cpu_pm.c
cpuset.c	cpuset: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:37 -08:00
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c	oom, PM: make OOM detection in the freezer path raceless	2015-02-11 17:06:03 -08:00
extable.c	ftrace/x86/extable: Add is_ftrace_trampoline() function	2014-11-19 15:25:26 -05:00
fork.c	mm: do not use mm->nr_pmds on !MMU configurations	2015-02-12 18:54:10 -08:00
freezer.c	freezer: remove obsolete comments in __thaw_task()	2014-10-21 23:44:20 +02:00
futex.c	all arches, signal: move restart_block to struct task_struct	2015-02-12 18:54:12 -08:00
futex_compat.c
groups.c	userns: Don't allow setgroups until a gid mapping has been setablished	2014-12-09 16:58:40 -06:00
hung_task.c
irq_work.c	percpu: Convert remaining __get_cpu_var uses in 3.18-rcX	2014-10-29 11:18:18 -04:00
jump_label.c
kallsyms.c	kernel/kallsyms.c: use __seq_open_private()	2014-10-14 02:18:16 +02:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks	locking/mcs: Better differentiate between MCS variants	2015-01-14 15:07:32 +01:00
Kconfig.preempt
kexec.c	kexec: simplify conditional	2015-02-17 14:34:51 -08:00
kmod.c	usermodehelper: kill the kmod_thread_locker logic	2014-12-10 17:41:17 -08:00
kprobes.c	kprobes: makes kprobes/enabled works correctly for optimized kprobes.	2015-02-13 21:21:42 -08:00
ksysfs.c
kthread.c	kernel/kthread.c: partial revert of 81c98869fa ("kthread: ensure locality of task_struct allocations")	2014-10-09 22:25:51 -04:00
latencytop.c
Makefile	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2015-02-11 20:25:11 -08:00
module-internal.h
module.c	kernel/module.c: do not inline do_init_module()	2015-02-17 14:34:53 -08:00
module_signing.c
notifier.c	rcu: Make SRCU optional by using CONFIG_SRCU	2015-01-06 11:04:29 -08:00
nsproxy.c	bury struct proc_ns in fs/proc	2014-12-04 14:34:54 -05:00
padata.c	padata: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:38 -08:00
panic.c	livepatch: kernel: add TAINT_LIVEPATCH	2014-12-22 15:40:48 +01:00
params.c	param: fix uninitialized read with CONFIG_DEBUG_LOCK_ALLOC	2015-01-20 11:38:31 +10:30
pid.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-12-16 15:53:03 -08:00
pid_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-12-16 15:53:03 -08:00
profile.c	profile: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:38 -08:00
ptrace.c	ptrace: remove linux/compat.h inclusion under CONFIG_COMPAT	2015-02-17 14:34:51 -08:00
range.c	kernel: avoid overflow in cmp_range	2015-01-17 10:02:23 +13:00
reboot.c	kernel: add support for kernel restart handler call chain	2014-09-26 00:00:06 -07:00
relay.c
resource.c	resources: Move struct resource_list_entry from ACPI into resource core	2015-02-05 15:09:25 +01:00
seccomp.c	seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO	2015-02-17 14:34:55 -08:00
signal.c	signal: use current->state helpers	2015-02-17 14:34:51 -08:00
smp.c	Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu	2014-10-15 07:48:18 +02:00
smpboot.c	smpboot: Add missing get_online_cpus() in smpboot_register_percpu_thread()	2015-01-23 11:33:51 +01:00
smpboot.h
softirq.c	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-09 15:24:03 -08:00
stacktrace.c	stacktrace: introduce snprint_stack_trace for buffer output	2014-12-13 12:42:48 -08:00
stop_machine.c
sys.c	kernel/sys.c: fix UNAME26 for 4.0	2015-02-28 09:57:51 -08:00
sys_ni.c	syscalls: implement execveat() system call	2014-12-13 12:42:51 -08:00
sysctl.c	mm, hugetlb: remove unnecessary lower bound on sysctl handlers"?	2015-02-10 14:30:34 -08:00
sysctl_binary.c	kernel: add panic_on_warn	2014-12-10 17:41:10 -08:00
system_certificates.S
system_keyring.c
task_work.c
taskstats.c	netlink: make nlmsg_end() and genlmsg_end() void	2015-01-18 01:03:45 -05:00
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
uid16.c	groups: Consolidate the setgroups permission checks	2014-12-05 17:19:27 -06:00
up.c
user-return-notifier.c
user.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2014-12-17 12:31:40 -08:00
user_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2014-12-17 12:31:40 -08:00
utsname.c	copy address of proc_ns_ops into ns_common	2014-12-04 14:34:47 -05:00
utsname_sysctl.c
watchdog.c	kernel/sched/clock.c: add another clock for use with the soft lockup watchdog	2015-02-12 18:54:13 -08:00
workqueue.c	workqueue: use %*pb[l] to format bitmaps including cpumasks and nodemasks	2015-02-13 21:21:37 -08:00
workqueue_internal.h