Note: This bug is displayed in read-only format because
the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Description of problem:
Kernel Panic always happen immediately whenever make "debug.panic_on_rcu_stall=1" set on RHEL7.4
Version-Release number of selected component (if applicable):
Kernel-3.10.0-693.el7 on RHEL7.4(GA) or later
How reproducible:
100%
Steps to Reproduce:
1.
# uname -r
3.10.0-693.1.1.el7.x86_64
2.
# cat /proc/sys/debug/panic_on_rcu_stall
0
3.
# echo 1 > /proc/sys/debug/panic_on_rcu_stall
Actual results:
kernel panic always happen.
Expected results:
When set to 1, calls panic() after RCU stall detection messages
When
Additional info:
It looks like RHEL commit 6cbfcf1526c74681ac81cda667f6f89016b47b8f backported upstream commit wrongly. We should have following diff on top of current RHEL7 code to backport upstream commit 088e9d253d3a4ab7e058dd84bb532c32dadf1882 correctly.
-------------------><--------------
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index f46e3e44c0af..981fb8baf895 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1000,6 +1000,8 @@ static void print_cpu_stall(struct rcu_state *rsp)
3 * rcu_jiffies_till_stall_check() + 3;
raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ panic_on_rcu_stall();
+
set_need_resched(); /* kick ourselves to get things going. */
}
@@ -1016,8 +1018,6 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
return;
j = ACCESS_ONCE(jiffies);
- panic_on_rcu_stall();
-
/*
* Lots of memory barriers to reject false positives.
*
-------------------><--------------
I will prepare a brew build with above diff, I hope that should resolve it.
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHSA-2018:1062