Steven Rostedt (VMware) 43b5bdbf96 fgraph: Initialize tracing_graph_pause at task creation ... commit 7e0a9220467dbcfdc5bc62825724f3e52e50ab31 upstream. On some archs, the idle task can call into cpu_suspend(). The cpu_suspend() will disable or pause function graph tracing, as there's some paths in bringing down the CPU that can have issues with its return address being modified. The task_struct structure has a "tracing_graph_pause" atomic counter, that when set to something other than zero, the function graph tracer will not modify the return address. The problem is that the tracing_graph_pause counter is initialized when the function graph tracer is enabled. This can corrupt the counter for the idle task if it is suspended in these architectures. CPU 1 CPU 2 ----- ----- do_idle() cpu_suspend() pause_graph_tracing() task_struct->tracing_graph_pause++ (0 -> 1) start_graph_tracing() for_each_online_cpu(cpu) { ftrace_graph_init_idle_task(cpu) task-struct->tracing_graph_pause = 0 (1 -> 0) unpause_graph_tracing() task_struct->tracing_graph_pause-- (0 -> -1) The above should have gone from 1 to zero, and enabled function graph tracing again. But instead, it is set to -1, which keeps it disabled. There's no reason that the field tracing_graph_pause on the task_struct can not be initialized at boot up. Cc: stable@vger.kernel.org Fixes: 380c4b1411 ("tracing/function-graph-tracer: append the tracing_graph_flag") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211339 Reported-by: pierre.gondois@arm.com Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-02-10 09:29:16 +01:00
..
bpf	bpf, preload: Fix build when $(O) points to a relative path	2021-02-10 09:29:13 +01:00
cgroup	cgroup: Fix memory leak when parsing multiple source parameters	2021-01-06 14:56:51 +01:00
configs
debug	kdb: Fix pager search for multi-line strings	2020-10-01 14:44:08 +01:00
dma	swiotlb: remove the tbl_dma_addr argument to swiotlb_tbl_map_single	2020-11-02 10:10:39 -05:00
entry	entry: Fix the incorrect ordering of lockdep and RCU check	2020-11-04 18:06:14 +01:00
events	exec: Transform exec_update_mutex into a rw_semaphore	2021-01-09 13:46:24 +01:00
gcov
irq	genirq/irqdomain: Don't try to free an interrupt that has no mapping	2020-12-30 11:53:25 +01:00
kcsan	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
livepatch	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
locking	locking/lockdep: Avoid noinstr warning for DEBUG_LOCKDEP	2021-02-07 15:37:14 +01:00
power	PM: hibernate: flush swap writer after marking	2021-02-03 23:28:40 +01:00
printk	printk: fix string termination for record_print_text()	2021-01-30 13:55:20 +01:00
rcu	rcu-tasks: Move RCU-tasks initialization to before early_initcall()	2021-01-19 18:27:28 +01:00
sched	sched: Reenable interrupts in do_sched_yield()	2020-12-30 11:52:59 +01:00
time	tick/sched: Remove bogus boot "safety" check	2021-01-06 14:56:55 +01:00
trace	fgraph: Initialize tracing_graph_pause at task creation	2021-02-10 09:29:16 +01:00
.gitignore
acct.c	kernel: acct.c: fix some kernel-doc nits	2020-10-16 11:11:19 -07:00
async.c
audit_fsnotify.c	fsnotify: generalize handle_inode_event()	2020-12-30 11:54:18 +01:00
audit_tree.c	fsnotify: generalize handle_inode_event()	2020-12-30 11:54:18 +01:00
audit_watch.c	fsnotify: generalize handle_inode_event()	2020-12-30 11:54:18 +01:00
audit.c
audit.h
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c	LSM: Signal to SafeSetID when setting group IDs	2020-10-13 09:17:34 -07:00
compat.c
configs.c
context_tracking.c
cpu_pm.c
cpu.c	kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling	2020-11-27 00:10:39 +11:00
crash_core.c
crash_dump.c
cred.c
delayacct.c
dma.c
exec_domain.c
exit.c	kernel/io_uring: cancel io_uring before task works	2021-01-30 13:55:18 +01:00
extable.c
fail_function.c	fail_function: Remove a redundant mutex unlock	2020-11-19 11:58:16 -08:00
fork.c	exec: Transform exec_update_mutex into a rw_semaphore	2021-01-09 13:46:24 +01:00
freezer.c
futex.c	futex: Handle faults correctly for PI futexes	2021-01-30 13:55:17 +01:00
gen_kheaders.sh
groups.c	LSM: Signal to SafeSetID when setting group IDs	2020-10-13 09:17:34 -07:00
hung_task.c	kernel/hung_task.c: make type annotations consistent	2020-11-02 12:14:19 -08:00
iomem.c
irq_work.c
jump_label.c	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
kallsyms.c	treewide: Convert macro and uses of __section(foo) to __section("foo")	2020-10-25 14:51:49 -07:00
kcmp.c	exec: Transform exec_update_mutex into a rw_semaphore	2021-01-09 13:46:24 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kexec_core.c	kernel: kexec: remove the lock operation of system_transition_mutex	2021-02-03 23:28:37 +01:00
kexec_elf.c
kexec_file.c	kernel/resource: move and rename IORESOURCE_MEM_DRIVER_MANAGED	2020-10-16 11:11:18 -07:00
kexec_internal.h
kexec.c	LSM: Introduce kernel_post_load_data() hook	2020-10-05 13:37:03 +02:00
kheaders.c
kmod.c
kprobes.c	kprobes: Tell lockdep about kprobe nesting	2020-11-04 09:46:06 -05:00
ksysfs.c
kthread.c	kthread: Extract KTHREAD_IS_PER_CPU	2021-02-07 15:37:17 +01:00
latencytop.c
Makefile	elfcore: fix building with clang	2020-12-11 14:02:14 -08:00
module_signature.c
module_signing.c
module-internal.h
module.c	module: delay kobject uevent until after module init call	2021-01-06 14:56:54 +01:00
notifier.c
nsproxy.c
padata.c
panic.c	panic: don't dump stack twice on warn	2020-11-14 11:26:04 -08:00
params.c	params: Replace zero-length array with flexible-array member	2020-10-29 17:22:59 -05:00
pid_namespace.c	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
pid.c	exec: Transform exec_update_mutex into a rw_semaphore	2021-01-09 13:46:24 +01:00
profile.c
ptrace.c	ptrace: Set PF_SUPERPRIV when checking capability	2020-11-17 12:53:22 -08:00
range.c	kernel.h: split out min()/max() et al. helpers	2020-10-16 11:11:19 -07:00
reboot.c	reboot: fix overflow parsing reboot cpu number	2020-11-14 11:26:03 -08:00
regset.c
relay.c	kernel/relay.c: drop unneeded initialization	2020-10-16 11:11:22 -07:00
resource.c	kernel/resource: make iomem_resource implicit in release_mem_region_adjustable()	2020-10-16 11:11:18 -07:00
rseq.c
scftorture.c
scs.c
seccomp.c	seccomp: Set PF_SUPERPRIV when checking capability	2020-11-17 12:53:22 -08:00
signal.c	ptrace: fix task_join_group_stop() for the case when current is traced	2020-11-02 12:14:19 -08:00
smp.c	Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2020-10-18 14:34:50 -07:00
smpboot.c	kthread: Extract KTHREAD_IS_PER_CPU	2021-02-07 15:37:17 +01:00
smpboot.h
softirq.c
stackleak.c
stacktrace.c
static_call.c	static_call: Fix return type of static_call_init	2020-10-02 21:18:25 +02:00
stop_machine.c	stop_machine, rcu: Mark functions as notrace	2020-10-26 12:12:27 +01:00
sys_ni.c	mm/madvise: introduce process_madvise() syscall: an external memory hinting API	2020-10-18 09:27:10 -07:00
sys.c	kernel/sys.c: fix prototype of prctl_get_tid_address()	2020-10-25 11:44:16 -07:00
sysctl-test.c
sysctl.c
task_work.c	task_work: cleanup notification modes	2020-10-17 15:05:30 -06:00
taskstats.c	taskstats: move specifying netlink policy back to ops	2020-10-02 19:11:12 -07:00
test_kprobes.c
torture.c
tracepoint.c	tracepoint: Replace zero-length array with flexible-array member	2020-10-29 17:22:59 -05:00
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c	usermodehelper: reset umask to default before executing user process	2020-10-06 10:31:52 -07:00
up.c
user_namespace.c	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
user-return-notifier.c
user.c
usermode_driver.c
utsname_sysctl.c
utsname.c
watch_queue.c
watchdog_hld.c
watchdog.c	kernel/watchdog: fix watchdog_allowed_mask not used warning	2020-11-14 11:26:03 -08:00
workqueue_internal.h
workqueue.c	workqueue: Restrict affinity change to rescuer	2021-02-07 15:37:17 +01:00