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| author | Oleg Nesterov <oleg@redhat.com> | 2015-08-21 19:42:50 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-10-06 11:25:16 -0700 |
| commit | 3a518b76af7bb411efe6dd090fbf098e29accb2e (patch) | |
| tree | 784edc06760ddaa84fbdfdcfe3ea52c9fb872fca /kernel | |
| parent | 82e8c565be8a72957570d7da8dd9b441db7bb648 (diff) | |
| download | linux-3a518b76af7bb411efe6dd090fbf098e29accb2e.tar.bz2 | |
rcu_sync: Add CONFIG_PROVE_RCU checks
This commit validates that the caller of rcu_sync_is_idle() holds the
corresponding type of RCU read-side lock, but only in kernels built
with CONFIG_PROVE_RCU=y. This validation is carried out via a new
rcu_sync_ops->held() method that is checked within rcu_sync_is_idle().
Note that although this does add code to the fast path, it only does so
in kernels built with CONFIG_PROVE_RCU=y.
Suggested-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/sync.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/kernel/rcu/sync.c b/kernel/rcu/sync.c index 5a9aa4c394f1..01c9807a7f73 100644 --- a/kernel/rcu/sync.c +++ b/kernel/rcu/sync.c @@ -23,21 +23,33 @@ #include <linux/rcu_sync.h> #include <linux/sched.h> +#ifdef CONFIG_PROVE_RCU +#define __INIT_HELD(func) .held = func, +#else +#define __INIT_HELD(func) +#endif + static const struct { void (*sync)(void); void (*call)(struct rcu_head *, void (*)(struct rcu_head *)); +#ifdef CONFIG_PROVE_RCU + int (*held)(void); +#endif } gp_ops[] = { [RCU_SYNC] = { .sync = synchronize_rcu, .call = call_rcu, + __INIT_HELD(rcu_read_lock_held) }, [RCU_SCHED_SYNC] = { .sync = synchronize_sched, .call = call_rcu_sched, + __INIT_HELD(rcu_read_lock_sched_held) }, [RCU_BH_SYNC] = { .sync = synchronize_rcu_bh, .call = call_rcu_bh, + __INIT_HELD(rcu_read_lock_bh_held) }, }; @@ -46,6 +58,14 @@ enum { CB_IDLE = 0, CB_PENDING, CB_REPLAY }; #define rss_lock gp_wait.lock +#ifdef CONFIG_PROVE_RCU +bool __rcu_sync_is_idle(struct rcu_sync *rsp) +{ + WARN_ON(!gp_ops[rsp->gp_type].held()); + return rsp->gp_state == GP_IDLE; +} +#endif + /** * rcu_sync_init() - Initialize an rcu_sync structure * @rsp: Pointer to rcu_sync structure to be initialized |