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Diffstat (limited to 'kernel/rcu/tree_stall.h')
-rw-r--r--kernel/rcu/tree_stall.h11
1 files changed, 7 insertions, 4 deletions
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index 5d666428546b..460efecd077b 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -504,7 +504,8 @@ static void print_cpu_stall_info(int cpu)
rcu_dynticks_in_eqs(rcu_dynticks_snap(cpu));
rcuc_starved = rcu_is_rcuc_kthread_starving(rdp, &j);
if (rcuc_starved)
- sprintf(buf, " rcuc=%ld jiffies(starved)", j);
+ // Print signed value, as negative values indicate a probable bug.
+ snprintf(buf, sizeof(buf), " rcuc=%ld jiffies(starved)", j);
pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%04x/%ld/%#lx softirq=%u/%u fqs=%ld%s%s\n",
cpu,
"O."[!!cpu_online(cpu)],
@@ -579,7 +580,7 @@ static void rcu_check_gp_kthread_expired_fqs_timer(void)
pr_err("%s kthread timer wakeup didn't happen for %ld jiffies! g%ld f%#x %s(%d) ->state=%#x\n",
rcu_state.name, (jiffies - jiffies_fqs),
(long)rcu_seq_current(&rcu_state.gp_seq),
- data_race(rcu_state.gp_flags),
+ data_race(READ_ONCE(rcu_state.gp_flags)), // Diagnostic read
gp_state_getname(RCU_GP_WAIT_FQS), RCU_GP_WAIT_FQS,
data_race(READ_ONCE(gpk->__state)));
pr_err("\tPossible timer handling issue on cpu=%d timer-softirq=%u\n",
@@ -628,7 +629,8 @@ static void print_other_cpu_stall(unsigned long gp_seq, unsigned long gps)
totqlen += rcu_get_n_cbs_cpu(cpu);
pr_err("\t(detected by %d, t=%ld jiffies, g=%ld, q=%lu ncpus=%d)\n",
smp_processor_id(), (long)(jiffies - gps),
- (long)rcu_seq_current(&rcu_state.gp_seq), totqlen, rcu_state.n_online_cpus);
+ (long)rcu_seq_current(&rcu_state.gp_seq), totqlen,
+ data_race(rcu_state.n_online_cpus)); // Diagnostic read
if (ndetected) {
rcu_dump_cpu_stacks();
@@ -689,7 +691,8 @@ static void print_cpu_stall(unsigned long gps)
totqlen += rcu_get_n_cbs_cpu(cpu);
pr_err("\t(t=%lu jiffies g=%ld q=%lu ncpus=%d)\n",
jiffies - gps,
- (long)rcu_seq_current(&rcu_state.gp_seq), totqlen, rcu_state.n_online_cpus);
+ (long)rcu_seq_current(&rcu_state.gp_seq), totqlen,
+ data_race(rcu_state.n_online_cpus)); // Diagnostic read
rcu_check_gp_kthread_expired_fqs_timer();
rcu_check_gp_kthread_starvation();