Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
srcu: Move rcu_is_watching() checks to srcu_read_{,un}lock_fast()
The rcu_is_watching() warnings are currently in the SRCU-tree
implementations of __srcu_read_lock_fast() and __srcu_read_unlock_fast().
However, this makes it difficult to create _notrace variants of
srcu_read_lock_fast() and srcu_read_unlock_fast(). This commit therefore
moves these checks to srcu_read_lock_fast(), srcu_read_unlock_fast(),
srcu_down_read_fast(), and srcu_up_read_fast().
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: <bpf@vger.kernel.org>
+4
-2
+4
include/linux/srcu.h
+4
include/linux/srcu.h
···
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{
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struct srcu_ctr __percpu *retval;
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+
RCU_LOCKDEP_WARN(!rcu_is_watching(), "RCU must be watching srcu_read_lock_fast().");
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srcu_check_read_flavor_force(ssp, SRCU_READ_FLAVOR_FAST);
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retval = __srcu_read_lock_fast(ssp);
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rcu_try_lock_acquire(&ssp->dep_map);
···
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static inline struct srcu_ctr __percpu *srcu_down_read_fast(struct srcu_struct *ssp) __acquires(ssp)
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{
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WARN_ON_ONCE(IS_ENABLED(CONFIG_PROVE_RCU) && in_nmi());
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+
RCU_LOCKDEP_WARN(!rcu_is_watching(), "RCU must be watching srcu_down_read_fast().");
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srcu_check_read_flavor_force(ssp, SRCU_READ_FLAVOR_FAST);
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return __srcu_read_lock_fast(ssp);
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}
···
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srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_FAST);
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srcu_lock_release(&ssp->dep_map);
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__srcu_read_unlock_fast(ssp, scp);
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+
RCU_LOCKDEP_WARN(!rcu_is_watching(), "RCU must be watching srcu_read_unlock_fast().");
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}
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/**
···
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WARN_ON_ONCE(IS_ENABLED(CONFIG_PROVE_RCU) && in_nmi());
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srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_FAST);
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__srcu_read_unlock_fast(ssp, scp);
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+
RCU_LOCKDEP_WARN(!rcu_is_watching(), "RCU must be watching srcu_up_read_fast().");
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}
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/**
-2
include/linux/srcutree.h
-2
include/linux/srcutree.h
···
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{
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struct srcu_ctr __percpu *scp = READ_ONCE(ssp->srcu_ctrp);
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-
RCU_LOCKDEP_WARN(!rcu_is_watching(), "RCU must be watching srcu_read_lock_fast().");
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if (!IS_ENABLED(CONFIG_NEED_SRCU_NMI_SAFE))
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this_cpu_inc(scp->srcu_locks.counter); /* Y */
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else
···
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this_cpu_inc(scp->srcu_unlocks.counter); /* Z */
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else
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atomic_long_inc(raw_cpu_ptr(&scp->srcu_unlocks)); /* Z */
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-
RCU_LOCKDEP_WARN(!rcu_is_watching(), "RCU must be watching srcu_read_unlock_fast().");
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}
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void __srcu_check_read_flavor(struct srcu_struct *ssp, int read_flavor);