[PATCH] kdb: Fix the deadlock issue in KDB debugging.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



master cpu : After executing the go command, a deadlock occurs.
slave cpu: may be performing thread migration,
        acquiring the running queue lock of master CPU.
        Then it was interrupted by kdb NMI and entered the nmi_handler process.
        (nmi_handle-> kgdb_nmicallback-> kgdb_cpu_enter
        while(1){ touch wathcdog}.)

example:
 BUG: spinlock lockup suspected on CPU#0, namex/10450
 lock: 0xffff881ffe823980, .magic: dead4ead, .owner: namexx/21888, .owner_cpu: 1
 ffff881741d00000 ffff881741c01000 0000000000000000 0000000000000000
 ffff881740f58e78 ffff881741cffdd0 ffffffff8147a7fc ffff881740f58f20
Call Trace:
 [<ffffffff81479e6d>] ? __schedule+0x16d/0xac0
 [<ffffffff8147a7fc>] ? schedule+0x3c/0x90
 [<ffffffff8147e71a>] ? schedule_hrtimeout_range_clock+0x10a/0x120
 [<ffffffff8147d22e>] ? mutex_unlock+0xe/0x10
 [<ffffffff811c839b>] ? ep_scan_ready_list+0x1db/0x1e0
 [<ffffffff8147e743>] ? schedule_hrtimeout_range+0x13/0x20
 [<ffffffff811c864a>] ? ep_poll+0x27a/0x3b0
 [<ffffffff8108c540>] ? wake_up_q+0x70/0x70
 [<ffffffff811c99a8>] ? SyS_epoll_wait+0xb8/0xd0
 [<ffffffff8147f296>] ? entry_SYSCALL_64_fastpath+0x12/0x75
 CPU: 0 PID: 10450 Comm: namex Tainted: G           O    4.4.65 #1
 Hardware name: Insyde Purley/Type2 - Board Product Name1, BIOS 05.21.51.0036 07/19/2019
  0000000000000000 ffff881ffe813c10 ffffffff8124e883 ffff881741c01000
  ffff881ffe823980 ffff881ffe813c38 ffffffff810a7f7f ffff881ffe823980
  000000007d2b7cd0 0000000000000001 ffff881ffe813c68 ffffffff810a80e0
  Call Trace:
  <#DB>  [<ffffffff8124e883>] dump_stack+0x85/0xc2
  [<ffffffff810a7f7f>] spin_dump+0x7f/0x100
  [<ffffffff810a80e0>] do_raw_spin_lock+0xa0/0x150
  [<ffffffff8147eb55>] _raw_spin_lock+0x15/0x20
  [<ffffffff8108c256>] try_to_wake_up+0x176/0x3d0
  [<ffffffff8108c4c5>] wake_up_process+0x15/0x20
  [<ffffffff8107b371>] insert_work+0x81/0xc0
  [<ffffffff8107b4e5>] __queue_work+0x135/0x390
  [<ffffffff8107b786>] queue_work_on+0x46/0x90
  [<ffffffff81313d28>] kgdboc_post_exp_handler+0x48/0x70
  [<ffffffff810ed488>] kgdb_cpu_enter+0x598/0x610
  [<ffffffff810ed6e2>] kgdb_handle_exception+0xf2/0x1f0
  [<ffffffff81054e21>] __kgdb_notify+0x71/0xd0
  [<ffffffff81054eb5>] kgdb_notify+0x35/0x70
  [<ffffffff81082e6a>] notifier_call_chain+0x4a/0x70
  [<ffffffff8108304d>] notify_die+0x3d/0x50
  [<ffffffff81017219>] do_int3+0x89/0x120
  [<ffffffff81480fb4>] int3+0x44/0x80

Signed-off-by: LiuYe <liu.yeC@xxxxxxx>
---
 drivers/tty/serial/kgdboc.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c
index 7ce7bb164..945318ef1 100644
--- a/drivers/tty/serial/kgdboc.c
+++ b/drivers/tty/serial/kgdboc.c
@@ -22,6 +22,9 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/serial_core.h>
+#include <linux/smp.h>
+
+#include "../kernel/sched/sched.h"

 #define MAX_CONFIG_LEN         40

@@ -399,7 +402,8 @@ static void kgdboc_post_exp_handler(void)
                dbg_restore_graphics = 0;
                con_debug_leave();
        }
-       kgdboc_restore_input();
+       if (!raw_spin_is_locked(&(cpu_rq(smp_processor_id())->lock)))
+               kgdboc_restore_input();
 }

 static struct kgdb_io kgdboc_io_ops = {
--
2.25.1

-------------------------------------------------------------------------------------------------------------------------------------
±¾Óʼþ¼°Æ丽¼þº¬ÓÐлªÈý¼¯Íŵı£ÃÜÐÅÏ¢£¬½öÏÞÓÚ·¢Ë͸øÉÏÃæµØÖ·ÖÐÁгö
µÄ¸öÈË»òȺ×é¡£½ûÖ¹ÈκÎÆäËûÈËÒÔÈκÎÐÎʽʹÓ㨰üÀ¨µ«²»ÏÞÓÚÈ«²¿»ò²¿·ÖµØй¶¡¢¸´ÖÆ¡¢
»òÉ¢·¢£©±¾ÓʼþÖеÄÐÅÏ¢¡£Èç¹ûÄú´íÊÕÁ˱¾Óʼþ£¬ÇëÄúÁ¢¼´µç»°»òÓʼþ֪ͨ·¢¼þÈ˲¢É¾³ý±¾
Óʼþ£¡
This e-mail and its attachments contain confidential information from New H3C, which is
intended only for the person or entity whose address is listed above. Any use of the
information contained herein in any way (including, but not limited to, total or partial
disclosure, reproduction, or dissemination) by persons other than the intended
recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender
by phone or email immediately and delete it!





[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux PPP]     [Linux FS]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Linmodem]     [Device Mapper]     [Linux Kernel for ARM]

  Powered by Linux