[PATCH RT 07/20] latencyhist: disable jump-labels

From: Steven Rostedt
Date: Wed Mar 02 2016 - 10:37:48 EST


3.18.27-rt27-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

Atleast on X86 we die a recursive death

|CPU: 3 PID: 585 Comm: bash Not tainted 4.4.1-rt4+ #198
|Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Debian-1.8.2-1 04/01/2014
|task: ffff88007ab4cd00 ti: ffff88007ab94000 task.ti: ffff88007ab94000
|RIP: 0010:[<ffffffff81684870>] [<ffffffff81684870>] int3+0x0/0x10
|RSP: 0018:ffff88013c107fd8 EFLAGS: 00010082
|RAX: ffff88007ab4cd00 RBX: ffffffff8100ceab RCX: 0000000080202001
|RDX: 0000000000000000 RSI: ffffffff8100ceab RDI: ffffffff810c78b2
|RBP: ffff88007ab97c10 R08: ffffffffff57b000 R09: 0000000000000000
|R10: ffff88013bb64790 R11: ffff88007ab4cd68 R12: ffffffff8100ceab
|R13: ffffffff810c78b2 R14: ffffffff810f8158 R15: ffffffff810f9120
|FS: 0000000000000000(0000) GS:ffff88013c100000(0063) knlGS:00000000f74e3940
|CS: 0010 DS: 002b ES: 002b CR0: 000000008005003b
|CR2: 0000000008cf6008 CR3: 000000013b169000 CR4: 00000000000006e0
|Call Trace:
| <#DB>
| [<ffffffff810f8158>] ? trace_preempt_off+0x18/0x170
| <<EOE>>
| [<ffffffff81077745>] preempt_count_add+0xa5/0xc0
| [<ffffffff810c78b2>] on_each_cpu+0x22/0x90
| [<ffffffff8100ceab>] text_poke_bp+0x5b/0xc0
| [<ffffffff8100a29c>] arch_jump_label_transform+0x8c/0xf0
| [<ffffffff8111c77c>] __jump_label_update+0x6c/0x80
| [<ffffffff8111c83a>] jump_label_update+0xaa/0xc0
| [<ffffffff8111ca54>] static_key_slow_inc+0x94/0xa0
| [<ffffffff810e0d8d>] tracepoint_probe_register_prio+0x26d/0x2c0
| [<ffffffff810e0df3>] tracepoint_probe_register+0x13/0x20
| [<ffffffff810fca78>] trace_event_reg+0x98/0xd0
| [<ffffffff810fcc8b>] __ftrace_event_enable_disable+0x6b/0x180
| [<ffffffff810fd5b8>] event_enable_write+0x78/0xc0
| [<ffffffff8117a768>] __vfs_write+0x28/0xe0
| [<ffffffff8117b025>] vfs_write+0xa5/0x180
| [<ffffffff8117bb76>] SyS_write+0x46/0xa0
| [<ffffffff81002c91>] do_fast_syscall_32+0xa1/0x1d0
| [<ffffffff81684d57>] sysenter_flags_fixed+0xd/0x17

during
echo 1 > /sys/kernel/debug/tracing/events/hist/preemptirqsoff_hist/enable

Reported-By: Christoph Mathys <eraserix@xxxxxxxxx>
Cc: stable-rt@xxxxxxxxxxxxxxx
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
arch/Kconfig | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/Kconfig b/arch/Kconfig
index 84d340b061a9..efb75aee313a 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -50,6 +50,7 @@ config KPROBES
config JUMP_LABEL
bool "Optimize very unlikely/likely branches"
depends on HAVE_ARCH_JUMP_LABEL
+ depends on (!INTERRUPT_OFF_HIST && !PREEMPT_OFF_HIST && !WAKEUP_LATENCY_HIST && !MISSED_TIMER_OFFSETS_HIST)
help
This option enables a transparent branch optimization that
makes certain almost-always-true or almost-always-false branch
--
2.7.0