From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753421AbbFSCT6 (ORCPT ); Thu, 18 Jun 2015 22:19:58 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:56475 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752214AbbFSCTu (ORCPT ); Thu, 18 Jun 2015 22:19:50 -0400 X-Helo: d03dlp03.boulder.ibm.com X-MailFrom: paulmck@linux.vnet.ibm.com X-RcptTo: linux-kernel@vger.kernel.org Date: Thu, 18 Jun 2015 19:19:43 -0700 From: "Paul E. McKenney" To: Ingo Molnar Cc: Andy Lutomirski , x86@kernel.org, linux-kernel@vger.kernel.org, =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Rik van Riel , Oleg Nesterov , Denys Vlasenko , Borislav Petkov , Kees Cook , Brian Gerst Subject: Re: [RFC/INCOMPLETE 01/13] context_tracking: Add context_tracking_assert_state Message-ID: <20150619021943.GA9505@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1d95640676a92a5ff7382e9c87517c12ea23ccd9.1434485184.git.luto@kernel.org> <20150617094114.GA3940@gmail.com> <20150617152756.GA3913@linux.vnet.ibm.com> <20150618095955.GB4528@gmail.com> <20150618225420.GQ3913@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150618225420.GQ3913@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15061902-0017-0000-0000-00000BC63821 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 18, 2015 at 03:54:20PM -0700, Paul E. McKenney wrote: > On Thu, Jun 18, 2015 at 11:59:55AM +0200, Ingo Molnar wrote: > > * Paul E. McKenney wrote: [ . . . ] > > > The thought is to rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN() > > > by analogy to WARN()? Easy to do if so! Or am I missing the point? > > > > Yeah, and inverting the condition. Assuming the condition was assert()-style > > inverted to begin with! :-) > > It appears to have been. ;-) > > Please see below for an untested patch. I made this be one big patch, > but could have one patch add RCU_LOCKDEP_WARN(), a series convert uses > from rcu_lockdep_assert() to RCU_LOCKDEP_WARN(), and a final patch > remove rcu_lockdep_assert(). Let me know! > > > and lockdep should be fixed too I suspect, lockdep_assert_held() was really a > > poorly chosen name I suspect, it should be 'lockdep_check_held()' or so? It has > > very little to do with the assert() interface. And this one actually builds and passes light rcutorture testing. ;-) Thanx, Paul ------------------------------------------------------------------------ commit eeacf89826376570bff42edec59fd1606ce1829f Author: Paul E. McKenney Date: Thu Jun 18 15:50:02 2015 -0700 rcu: Rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN() This commit renames rcu_lockdep_assert() to RCU_LOCKDEP_WARN() for consistency with the WARN() series of macros. This also requires inverting the sense of the conditional, which this commit also does. Reported-by: Ingo Molnar Signed-off-by: Paul E. McKenney diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt index 5746b0c77f3e..adc2184009c5 100644 --- a/Documentation/RCU/whatisRCU.txt +++ b/Documentation/RCU/whatisRCU.txt @@ -883,7 +883,7 @@ All: lockdep-checked RCU-protected pointer access rcu_access_pointer rcu_dereference_raw - rcu_lockdep_assert + RCU_LOCKDEP_WARN rcu_sleep_check RCU_NONIDLE diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index d4298feaa6fb..127ecd687c1d 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -54,9 +54,9 @@ static DEFINE_MUTEX(mce_chrdev_read_mutex); #define rcu_dereference_check_mce(p) \ ({ \ - rcu_lockdep_assert(rcu_read_lock_sched_held() || \ - lockdep_is_held(&mce_chrdev_read_mutex), \ - "suspicious rcu_dereference_check_mce() usage"); \ + RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \ + !lockdep_is_held(&mce_chrdev_read_mutex), \ + "suspicious rcu_dereference_check_mce() usage"); \ smp_load_acquire(&(p)); \ }) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 324ab5247687..37f827cb78ed 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -136,7 +136,7 @@ enum ctx_state ist_enter(struct pt_regs *regs) preempt_count_add(HARDIRQ_OFFSET); /* This code is a bit fragile. Test it. */ - rcu_lockdep_assert(rcu_is_watching(), "ist_enter didn't work"); + RCU_LOCKDEP_WARN(!rcu_is_watching(), "ist_enter didn't work"); return prev_state; } diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 677fb2843553..3b188f20b43f 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -110,8 +110,8 @@ static DEFINE_MUTEX(dev_opp_list_lock); #define opp_rcu_lockdep_assert() \ do { \ - rcu_lockdep_assert(rcu_read_lock_held() || \ - lockdep_is_held(&dev_opp_list_lock), \ + RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ + !lockdep_is_held(&dev_opp_list_lock), \ "Missing rcu_read_lock() or " \ "dev_opp_list_lock protection"); \ } while (0) diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 230f87bdf5ad..910c75f6cd0b 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -83,8 +83,8 @@ static inline struct file *__fcheck_files(struct files_struct *files, unsigned i static inline struct file *fcheck_files(struct files_struct *files, unsigned int fd) { - rcu_lockdep_assert(rcu_read_lock_held() || - lockdep_is_held(&files->file_lock), + RCU_LOCKDEP_WARN(!rcu_read_lock_held() && + !lockdep_is_held(&files->file_lock), "suspicious rcu_dereference_check() usage"); return __fcheck_files(files, fd); } diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 2f4a93a8ceab..e9e04c32cb4c 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -537,14 +537,14 @@ static inline int rcu_read_lock_sched_held(void) #ifdef CONFIG_PROVE_RCU /** - * rcu_lockdep_assert - emit lockdep splat if specified condition not met + * RCU_LOCKDEP_WARN - emit lockdep splat if specified condition is met * @c: condition to check * @s: informative message */ -#define rcu_lockdep_assert(c, s) \ +#define RCU_LOCKDEP_WARN(c, s) \ do { \ static bool __section(.data.unlikely) __warned; \ - if (debug_lockdep_rcu_enabled() && !__warned && !(c)) { \ + if (debug_lockdep_rcu_enabled() && !__warned && (c)) { \ __warned = true; \ lockdep_rcu_suspicious(__FILE__, __LINE__, s); \ } \ @@ -553,8 +553,8 @@ static inline int rcu_read_lock_sched_held(void) #if defined(CONFIG_PROVE_RCU) && !defined(CONFIG_PREEMPT_RCU) static inline void rcu_preempt_sleep_check(void) { - rcu_lockdep_assert(!lock_is_held(&rcu_lock_map), - "Illegal context switch in RCU read-side critical section"); + RCU_LOCKDEP_WARN(lock_is_held(&rcu_lock_map), + "Illegal context switch in RCU read-side critical section"); } #else /* #ifdef CONFIG_PROVE_RCU */ static inline void rcu_preempt_sleep_check(void) @@ -565,15 +565,15 @@ static inline void rcu_preempt_sleep_check(void) #define rcu_sleep_check() \ do { \ rcu_preempt_sleep_check(); \ - rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map), \ - "Illegal context switch in RCU-bh read-side critical section"); \ - rcu_lockdep_assert(!lock_is_held(&rcu_sched_lock_map), \ - "Illegal context switch in RCU-sched read-side critical section"); \ + RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map), \ + "Illegal context switch in RCU-bh read-side critical section"); \ + RCU_LOCKDEP_WARN(lock_is_held(&rcu_sched_lock_map), \ + "Illegal context switch in RCU-sched read-side critical section"); \ } while (0) #else /* #ifdef CONFIG_PROVE_RCU */ -#define rcu_lockdep_assert(c, s) do { } while (0) +#define RCU_LOCKDEP_WARN(c, s) do { } while (0) #define rcu_sleep_check() do { } while (0) #endif /* #else #ifdef CONFIG_PROVE_RCU */ @@ -604,13 +604,13 @@ static inline void rcu_preempt_sleep_check(void) ({ \ /* Dependency order vs. p above. */ \ typeof(*p) *________p1 = (typeof(*p) *__force)lockless_dereference(p); \ - rcu_lockdep_assert(c, "suspicious rcu_dereference_check() usage"); \ + RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_check() usage"); \ rcu_dereference_sparse(p, space); \ ((typeof(*p) __force __kernel *)(________p1)); \ }) #define __rcu_dereference_protected(p, c, space) \ ({ \ - rcu_lockdep_assert(c, "suspicious rcu_dereference_protected() usage"); \ + RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_protected() usage"); \ rcu_dereference_sparse(p, space); \ ((typeof(*p) __force __kernel *)(p)); \ }) @@ -849,8 +849,8 @@ static inline void rcu_read_lock(void) __rcu_read_lock(); __acquire(RCU); rcu_lock_acquire(&rcu_lock_map); - rcu_lockdep_assert(rcu_is_watching(), - "rcu_read_lock() used illegally while idle"); + RCU_LOCKDEP_WARN(!rcu_is_watching(), + "rcu_read_lock() used illegally while idle"); } /* @@ -900,8 +900,8 @@ static inline void rcu_read_lock(void) */ static inline void rcu_read_unlock(void) { - rcu_lockdep_assert(rcu_is_watching(), - "rcu_read_unlock() used illegally while idle"); + RCU_LOCKDEP_WARN(!rcu_is_watching(), + "rcu_read_unlock() used illegally while idle"); __release(RCU); __rcu_read_unlock(); rcu_lock_release(&rcu_lock_map); /* Keep acq info for rls diags. */ @@ -929,8 +929,8 @@ static inline void rcu_read_lock_bh(void) local_bh_disable(); __acquire(RCU_BH); rcu_lock_acquire(&rcu_bh_lock_map); - rcu_lockdep_assert(rcu_is_watching(), - "rcu_read_lock_bh() used illegally while idle"); + RCU_LOCKDEP_WARN(!rcu_is_watching(), + "rcu_read_lock_bh() used illegally while idle"); } /* @@ -940,8 +940,8 @@ static inline void rcu_read_lock_bh(void) */ static inline void rcu_read_unlock_bh(void) { - rcu_lockdep_assert(rcu_is_watching(), - "rcu_read_unlock_bh() used illegally while idle"); + RCU_LOCKDEP_WARN(!rcu_is_watching(), + "rcu_read_unlock_bh() used illegally while idle"); rcu_lock_release(&rcu_bh_lock_map); __release(RCU_BH); local_bh_enable(); @@ -965,8 +965,8 @@ static inline void rcu_read_lock_sched(void) preempt_disable(); __acquire(RCU_SCHED); rcu_lock_acquire(&rcu_sched_lock_map); - rcu_lockdep_assert(rcu_is_watching(), - "rcu_read_lock_sched() used illegally while idle"); + RCU_LOCKDEP_WARN(!rcu_is_watching(), + "rcu_read_lock_sched() used illegally while idle"); } /* Used by lockdep and tracing: cannot be traced, cannot call lockdep. */ @@ -983,8 +983,8 @@ static inline notrace void rcu_read_lock_sched_notrace(void) */ static inline void rcu_read_unlock_sched(void) { - rcu_lockdep_assert(rcu_is_watching(), - "rcu_read_unlock_sched() used illegally while idle"); + RCU_LOCKDEP_WARN(!rcu_is_watching(), + "rcu_read_unlock_sched() used illegally while idle"); rcu_lock_release(&rcu_sched_lock_map); __release(RCU_SCHED); preempt_enable(); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 469dd547770c..ad2d0162532a 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -104,8 +104,8 @@ static DEFINE_SPINLOCK(cgroup_idr_lock); static DEFINE_SPINLOCK(release_agent_path_lock); #define cgroup_assert_mutex_or_rcu_locked() \ - rcu_lockdep_assert(rcu_read_lock_held() || \ - lockdep_is_held(&cgroup_mutex), \ + RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ + !lockdep_is_held(&cgroup_mutex), \ "cgroup_mutex or RCU read lock required"); /* diff --git a/kernel/pid.c b/kernel/pid.c index 4fd07d5b7baf..ca368793808e 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -451,9 +451,8 @@ EXPORT_SYMBOL(pid_task); */ struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns) { - rcu_lockdep_assert(rcu_read_lock_held(), - "find_task_by_pid_ns() needs rcu_read_lock()" - " protection"); + RCU_LOCKDEP_WARN(!rcu_read_lock_held(), + "find_task_by_pid_ns() needs rcu_read_lock() protection"); return pid_task(find_pid_ns(nr, ns), PIDTYPE_PID); } diff --git a/kernel/rcu/srcu.c b/kernel/rcu/srcu.c index de35087c92a5..d3fcb2ec8536 100644 --- a/kernel/rcu/srcu.c +++ b/kernel/rcu/srcu.c @@ -415,11 +415,11 @@ static void __synchronize_srcu(struct srcu_struct *sp, int trycount) struct rcu_head *head = &rcu.head; bool done = false; - rcu_lockdep_assert(!lock_is_held(&sp->dep_map) && - !lock_is_held(&rcu_bh_lock_map) && - !lock_is_held(&rcu_lock_map) && - !lock_is_held(&rcu_sched_lock_map), - "Illegal synchronize_srcu() in same-type SRCU (or RCU) read-side critical section"); + RCU_LOCKDEP_WARN(lock_is_held(&sp->dep_map) || + lock_is_held(&rcu_bh_lock_map) || + lock_is_held(&rcu_lock_map) || + lock_is_held(&rcu_sched_lock_map), + "Illegal synchronize_srcu() in same-type SRCU (or in RCU) read-side critical section"); might_sleep(); init_completion(&rcu.completion); diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c index 591af0cb7b9f..e888602d5c56 100644 --- a/kernel/rcu/tiny.c +++ b/kernel/rcu/tiny.c @@ -191,10 +191,10 @@ static void rcu_process_callbacks(struct softirq_action *unused) */ void synchronize_sched(void) { - rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map) && - !lock_is_held(&rcu_lock_map) && - !lock_is_held(&rcu_sched_lock_map), - "Illegal synchronize_sched() in RCU read-side critical section"); + RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) || + lock_is_held(&rcu_lock_map) || + lock_is_held(&rcu_sched_lock_map), + "Illegal synchronize_sched() in RCU read-side critical section"); cond_resched(); } EXPORT_SYMBOL_GPL(synchronize_sched); diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index c844ef3c2fae..78d0a87ff354 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -644,12 +644,12 @@ static void rcu_eqs_enter_common(long long oldval, bool user) * It is illegal to enter an extended quiescent state while * in an RCU read-side critical section. */ - rcu_lockdep_assert(!lock_is_held(&rcu_lock_map), - "Illegal idle entry in RCU read-side critical section."); - rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map), - "Illegal idle entry in RCU-bh read-side critical section."); - rcu_lockdep_assert(!lock_is_held(&rcu_sched_lock_map), - "Illegal idle entry in RCU-sched read-side critical section."); + RCU_LOCKDEP_WARN(lock_is_held(&rcu_lock_map), + "Illegal idle entry in RCU read-side critical section."); + RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map), + "Illegal idle entry in RCU-bh read-side critical section."); + RCU_LOCKDEP_WARN(lock_is_held(&rcu_sched_lock_map), + "Illegal idle entry in RCU-sched read-side critical section."); } /* @@ -3162,10 +3162,10 @@ static inline int rcu_blocking_is_gp(void) */ void synchronize_sched(void) { - rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map) && - !lock_is_held(&rcu_lock_map) && - !lock_is_held(&rcu_sched_lock_map), - "Illegal synchronize_sched() in RCU-sched read-side critical section"); + RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) || + lock_is_held(&rcu_lock_map) || + lock_is_held(&rcu_sched_lock_map), + "Illegal synchronize_sched() in RCU-sched read-side critical section"); if (rcu_blocking_is_gp()) return; if (rcu_gp_is_expedited()) @@ -3189,10 +3189,10 @@ EXPORT_SYMBOL_GPL(synchronize_sched); */ void synchronize_rcu_bh(void) { - rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map) && - !lock_is_held(&rcu_lock_map) && - !lock_is_held(&rcu_sched_lock_map), - "Illegal synchronize_rcu_bh() in RCU-bh read-side critical section"); + RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) || + lock_is_held(&rcu_lock_map) || + lock_is_held(&rcu_sched_lock_map), + "Illegal synchronize_rcu_bh() in RCU-bh read-side critical section"); if (rcu_blocking_is_gp()) return; if (rcu_gp_is_expedited()) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 85addcf7d184..07bd9fb393b4 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -522,10 +522,10 @@ EXPORT_SYMBOL_GPL(call_rcu); */ void synchronize_rcu(void) { - rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map) && - !lock_is_held(&rcu_lock_map) && - !lock_is_held(&rcu_sched_lock_map), - "Illegal synchronize_rcu() in RCU read-side critical section"); + RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) || + lock_is_held(&rcu_lock_map) || + lock_is_held(&rcu_sched_lock_map), + "Illegal synchronize_rcu() in RCU read-side critical section"); if (!rcu_scheduler_active) return; if (rcu_gp_is_expedited()) diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index a0a0dd03c73a..47268fb1d27b 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -589,8 +589,8 @@ EXPORT_SYMBOL_GPL(call_rcu_tasks); void synchronize_rcu_tasks(void) { /* Complain if the scheduler has not started. */ - rcu_lockdep_assert(!rcu_scheduler_active, - "synchronize_rcu_tasks called too soon"); + RCU_LOCKDEP_WARN(rcu_scheduler_active, + "synchronize_rcu_tasks called too soon"); /* Wait for the grace period. */ wait_rcu_gp(call_rcu_tasks); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index fe22f7510bce..7956c016e750 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1987,8 +1987,8 @@ unsigned long to_ratio(u64 period, u64 runtime) #ifdef CONFIG_SMP inline struct dl_bw *dl_bw_of(int i) { - rcu_lockdep_assert(rcu_read_lock_sched_held(), - "sched RCU must be held"); + RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(), + "sched RCU must be held"); return &cpu_rq(i)->rd->dl_bw; } @@ -1997,8 +1997,8 @@ static inline int dl_bw_cpus(int i) struct root_domain *rd = cpu_rq(i)->rd; int cpus = 0; - rcu_lockdep_assert(rcu_read_lock_sched_held(), - "sched RCU must be held"); + RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(), + "sched RCU must be held"); for_each_cpu_and(i, rd->span, cpu_active_mask) cpus++; diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 586ad91300b0..80bc8dc8d286 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -338,14 +338,14 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq); #include #define assert_rcu_or_pool_mutex() \ - rcu_lockdep_assert(rcu_read_lock_sched_held() || \ - lockdep_is_held(&wq_pool_mutex), \ - "sched RCU or wq_pool_mutex should be held") + RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \ + !lockdep_is_held(&wq_pool_mutex), \ + "sched RCU or wq_pool_mutex should be held") #define assert_rcu_or_wq_mutex(wq) \ - rcu_lockdep_assert(rcu_read_lock_sched_held() || \ - lockdep_is_held(&wq->mutex), \ - "sched RCU or wq->mutex should be held") + RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \ + !lockdep_is_held(&wq->mutex), \ + "sched RCU or wq->mutex should be held") #define for_each_cpu_worker_pool(pool, cpu) \ for ((pool) = &per_cpu(cpu_worker_pools, cpu)[0]; \ diff --git a/security/device_cgroup.c b/security/device_cgroup.c index 188c1d26393b..73455089feef 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -400,9 +400,9 @@ static bool verify_new_ex(struct dev_cgroup *dev_cgroup, { bool match = false; - rcu_lockdep_assert(rcu_read_lock_held() || - lockdep_is_held(&devcgroup_mutex), - "device_cgroup:verify_new_ex called without proper synchronization"); + RCU_LOCKDEP_WARN(!rcu_read_lock_held() && + lockdep_is_held(&devcgroup_mutex), + "device_cgroup:verify_new_ex called without proper synchronization"); if (dev_cgroup->behavior == DEVCG_DEFAULT_ALLOW) { if (behavior == DEVCG_DEFAULT_ALLOW) {