Commit 969974e5 authored May 22, 2019 by Paul E. McKenney

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>

parent 921bb5fa

kernel/rcu/tree_plugin.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -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

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