rcu/nocb: Suppress uninitialized false-positive in nocb_gp_wait()

Some compilers complain that wait_gp_seq might be used uninitialized
in nocb_gp_wait().  This cannot actually happen because when wait_gp_seq
is uninitialized, needwait_gp must be false, which prevents wait_gp_seq
from being used.  But this analysis is apparently beyond some compilers,
so this commit adds a bogus initialization of wait_gp_seq for the sole
purpose of suppressing the false-positive warning.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit is contained in:
Paul E. McKenney 2019-05-22 09:35:11 -07:00
parent 921bb5fad1
commit 969974e5c5

View File

@ -1668,12 +1668,12 @@ static void nocb_gp_wait(struct rcu_data *my_rdp)
unsigned long cur_gp_seq;
unsigned long flags;
bool gotcbs;
bool needwait_gp = false;
bool needwait_gp = false; // This prevents actual uninitialized use.
bool needwake;
bool needwake_gp;
struct rcu_data *rdp;
struct rcu_node *rnp;
unsigned long wait_gp_seq;
unsigned long wait_gp_seq = 0; // Suppress "use uninitialized" warning.
/*
* Each pass through the following loop checks for CBs and for the