lkml.org 
[lkml]   [2018]   [Sep]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] genirq: Avoid race between cpu hot plug and irq_desc() allocation paths
Date
One of the cores might have just allocated irq_desc() and other core
might be doing irq migration in the hot plug path. In the hot plug path
during the IRQ migration, for_each_active_irq macro is trying to get
irqs whose bits are set in allocated_irqs bit map but there is no return
value check after irq_to_desc for desc validity.

[ 24.566381] msm_thermal:do_core_control Set Offline: CPU4 Temp: 73
[ 24.568821] Unable to handle kernel NULL pointer dereference at virtual address 000000a4
[ 24.568931] pgd = ffffffc002184000
[ 24.568995] [000000a4] *pgd=0000000178df5003, *pud=0000000178df5003, *pmd=0000000178df6003, *pte=0060000017a00707
[ 24.569153] ------------[ cut here ]------------
[ 24.569228] Kernel BUG at ffffffc0000f3060 [verbose debug info unavailable]
[ 24.569334] Internal error: Oops - BUG: 96000005 [#1] PREEMPT SMP
[ 24.569422] Modules linked in:
[ 24.569486] CPU: 4 PID: 28 Comm: migration/4 Tainted: G W 4.4.8-perf-9407222-eng #1
[ 24.569684] task: ffffffc0f28f0e80 ti: ffffffc0f2a84000 task.ti: ffffffc0f2a84000
[ 24.569785] PC is at do_raw_spin_lock+0x20/0x160
[ 24.569859] LR is at _raw_spin_lock+0x34/0x40
[ 24.569931] pc : [<ffffffc0000f3060>] lr : [<ffffffc001023dec>] pstate: 200001c5
[ 24.570029] sp : ffffffc0f2a87bc0
[ 24.570091] x29: ffffffc0f2a87bc0 x28: ffffffc001033988
[ 24.570174] x27: ffffffc001adebb0 x26: 0000000000000000
[ 24.570257] x25: 00000000000000a0 x24: 0000000000000020
[ 24.570339] x23: ffffffc001033978 x22: ffffffc001adeb80
[ 24.570421] x21: 000000000000027e x20: 0000000000000000
[ 24.570502] x19: 00000000000000a0 x18: 000000000000000d
[ 24.570584] x17: 0000000000005f00 x16: 0000000000000003
[ 24.570666] x15: 000000000000bd39 x14: 0ffffffffffffffe
[ 24.570748] x13: 0000000000000000 x12: 0000000000000018
[ 24.570829] x11: 0101010101010101 x10: 7f7f7f7f7f7f7f7f
[ 24.570911] x9 : fefefefeff332e6d x8 : 7f7f7f7f7f7f7f7f
[ 24.570993] x7 : ffffffc00344f6a0 x6 : 0000000000000000
[ 24.571075] x5 : 0000000000000001 x4 : ffffffc00344f488
[ 24.571157] x3 : 0000000000000000 x2 : 0000000000000000
[ 24.571238] x1 : ffffffc0f2a84000 x0 : 0000000000004ead
...
...
...
[ 24.581324] Call trace:
[ 24.581379] [<ffffffc0000f3060>] do_raw_spin_lock+0x20/0x160
[ 24.581463] [<ffffffc001023dec>] _raw_spin_lock+0x34/0x40
[ 24.581546] [<ffffffc000103f10>] irq_migrate_all_off_this_cpu+0x84/0x1c4
[ 24.581641] [<ffffffc00008ec84>] __cpu_disable+0x54/0x74
[ 24.581722] [<ffffffc0000a3368>] take_cpu_down+0x1c/0x58
[ 24.581803] [<ffffffc00013ac08>] multi_cpu_stop+0xb0/0x10c
[ 24.581885] [<ffffffc00013ad60>] cpu_stopper_thread+0xb8/0x184
[ 24.581972] [<ffffffc0000c4920>] smpboot_thread_fn+0x26c/0x290
[ 24.582057] [<ffffffc0000c0f84>] kthread+0x100/0x108
[ 24.582135] Code: aa0003f3 aa1e03e0 d503201f 5289d5a0 (b9400661)
[ 24.582224] ---[ end trace 609f38584306f5d9 ]---

Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Prakruthi Deepak Heragu <pheragu@codeaurora.org>
---
kernel/irq/cpuhotplug.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c
index 5b1072e..17c5e71 100644
--- a/kernel/irq/cpuhotplug.c
+++ b/kernel/irq/cpuhotplug.c
@@ -160,6 +160,9 @@ void irq_migrate_all_off_this_cpu(void)
bool affinity_broken;

desc = irq_to_desc(irq);
+ if (!desc)
+ continue;
+
raw_spin_lock(&desc->lock);
affinity_broken = migrate_one_irq(desc);
raw_spin_unlock(&desc->lock);
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
\
 
 \ /
  Last update: 2018-09-05 19:05    [W:0.050 / U:3.152 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site