The following commit has been merged into the core/rcu branch of tip:
Commit-ID: 1ef5a442a113d140580b3b8bbd6f50c9f7746397
Gitweb:
https://git.kernel.org/tip/1ef5a442a113d140580b3b8bbd6f50c9f7746397
Author: Paul E. McKenney <paul...@kernel.org>
AuthorDate: Tue, 23 Jun 2020 20:57:59 -07:00
Committer: Paul E. McKenney <paul...@kernel.org>
CommitterDate: Mon, 24 Aug 2020 18:36:08 -07:00
rcu: Add READ_ONCE() to rcu_do_batch() access to rcu_cpu_stall_ftrace_dump
Given that sysfs can change the value of rcu_cpu_stall_ftrace_dump at any
time, this commit adds a READ_ONCE() to the accesses to that variable.
Signed-off-by: Paul E. McKenney <paul...@kernel.org>
---
kernel/rcu/tree_stall.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index a1780a6..0fde39b 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -623,7 +623,7 @@ static void check_cpu_stall(struct rcu_data *rdp)
/* We haven't checked in, so go dump stack. */
print_cpu_stall(gps);
- if (rcu_cpu_stall_ftrace_dump)
+ if (READ_ONCE(rcu_cpu_stall_ftrace_dump))
rcu_ftrace_dump(DUMP_ALL);
} else if (rcu_gp_in_progress() &&
@@ -632,7 +632,7 @@ static void check_cpu_stall(struct rcu_data *rdp)
/* They had a few time units to dump stack, so complain. */
print_other_cpu_stall(gs2, gps);
- if (rcu_cpu_stall_ftrace_dump)
+ if (READ_ONCE(rcu_cpu_stall_ftrace_dump))
rcu_ftrace_dump(DUMP_ALL);
}
}
