linux/arch/arc
Vineet Gupta 328d2168ca ARC: stack unwinding: avoid indefinite looping
Currently stack unwinder is a while(1) loop which relies on the dwarf
unwinder to signal termination, which in turn relies on dwarf info to do
so. This in theory could cause an infinite loop if the dwarf info was
somehow messed up or the register contents were etc.

This fix thus detects the excessive looping and breaks the loop.

| Mem: 26184K used, 1009136K free, 0K shrd, 0K buff, 14416K cached
| CPU:  0.0% usr 72.8% sys  0.0% nic 27.1% idle  0.0% io  0.0% irq  0.0% sirq
| Load average: 4.33 2.60 1.11 2/74 139
|   PID  PPID USER     STAT   VSZ %VSZ CPU %CPU COMMAND
|   133     2 root     SWN      0  0.0   3 22.9 [rcu_torture_rea]
|   132     2 root     SWN      0  0.0   0 22.0 [rcu_torture_rea]
|   131     2 root     SWN      0  0.0   3 21.5 [rcu_torture_rea]
|   126     2 root     RW       0  0.0   2  5.4 [rcu_torture_wri]
|   129     2 root     SWN      0  0.0   0  0.2 [rcu_torture_fak]
|   137     2 root     SW       0  0.0   0  0.2 [rcu_torture_cbf]
|   127     2 root     SWN      0  0.0   0  0.1 [rcu_torture_fak]
|   138   115 root     R     1464  0.1   2  0.1 top
|   130     2 root     SWN      0  0.0   0  0.1 [rcu_torture_fak]
|   128     2 root     SWN      0  0.0   0  0.1 [rcu_torture_fak]
|   115     1 root     S     1472  0.1   1  0.0 -/bin/sh
|   104     1 root     S     1464  0.1   0  0.0 inetd
|     1     0 root     S     1456  0.1   2  0.0 init
|    78     1 root     S     1456  0.1   0  0.0 syslogd -O /var/log/messages
|   134     2 root     SW       0  0.0   2  0.0 [rcu_torture_sta]
|    10     2 root     IW       0  0.0   1  0.0 [rcu_preempt]
|    88     2 root     IW       0  0.0   1  0.0 [kworker/1:1-eve]
|    66     2 root     IW       0  0.0   2  0.0 [kworker/2:2-eve]
|    39     2 root     IW       0  0.0   2  0.0 [kworker/2:1-eve]
| unwinder looping too long, aborting !

Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2020-11-02 11:45:08 -08:00
..
boot ARC: [dts] fix the errors detected by dtbs_check 2020-10-05 21:02:29 -07:00
configs ARC: [plat-eznps]: Drop support for EZChip NPS platform 2020-10-05 21:02:29 -07:00
include treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
kernel ARC: stack unwinding: avoid indefinite looping 2020-11-02 11:45:08 -08:00
lib treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
mm ARC changes for 5.10 2020-10-20 09:09:44 -07:00
oprofile treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
plat-axs10x treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
plat-hsdk treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
plat-sim ARC: merge HAPS-HS with nSIM-HS configs 2019-10-28 12:12:31 -07:00
plat-tb10x treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
Kbuild treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
Kconfig Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-10-22 09:59:21 -07:00
Kconfig.debug Kconfig: consolidate the "Kernel hacking" menu 2018-08-02 08:06:48 +09:00
Makefile ARC: [plat-eznps]: Drop support for EZChip NPS platform 2020-10-05 21:02:29 -07:00