From 1c21f14ec48a2256fb03682b24dddd23eacdc96f Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 4 Mar 2009 13:51:13 +0100 Subject: lockdep: fix incorrect state name In the recent mark_lock_irq() rework a bug snuck in that would report the state of write locks causing irq inversion under a read lock as a read lock. Fix this by masking the read bit of the state when validating write dependencies. Reported-by: Andrew Morton Signed-off-by: Peter Zijlstra LKML-Reference: <1236172646.5330.7450.camel@laptop> Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'kernel/lockdep.c') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 022d2ed7fd8..ef6584fd9fe 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -2015,7 +2015,8 @@ typedef int (*check_usage_f)(struct task_struct *, struct held_lock *, enum lock_usage_bit bit, const char *name); static int -mark_lock_irq(struct task_struct *curr, struct held_lock *this, int new_bit) +mark_lock_irq(struct task_struct *curr, struct held_lock *this, + enum lock_usage_bit new_bit) { int excl_bit = exclusive_bit(new_bit); int read = new_bit & 1; @@ -2043,7 +2044,7 @@ mark_lock_irq(struct task_struct *curr, struct held_lock *this, int new_bit) * states. */ if ((!read || !dir || STRICT_READ_CHECKS) && - !usage(curr, this, excl_bit, state_name(new_bit))) + !usage(curr, this, excl_bit, state_name(new_bit & ~1))) return 0; /* -- cgit v1.2.3 From 26575e28df5eb2050c02369843faba38cecb4d8c Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 4 Mar 2009 14:53:24 +0100 Subject: lockdep: remove extra "irq" string Impact: clarify lockdep printk text print_irq_inversion_bug() gets handed state strings of the form "HARDIRQ", "SOFTIRQ", "RECLAIM_FS" and appends "-irq-{un,}safe" to them, which is either redudant for *IRQ or confusing in the RECLAIM_FS case. Signed-off-by: Peter Zijlstra LKML-Reference: <1236175192.5330.7585.camel@laptop> Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/lockdep.c') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index ef6584fd9fe..02014f7ccc8 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -1900,9 +1900,9 @@ print_irq_inversion_bug(struct task_struct *curr, struct lock_class *other, curr->comm, task_pid_nr(curr)); print_lock(this); if (forwards) - printk("but this lock took another, %s-irq-unsafe lock in the past:\n", irqclass); + printk("but this lock took another, %s-unsafe lock in the past:\n", irqclass); else - printk("but this lock was taken by another, %s-irq-safe lock in the past:\n", irqclass); + printk("but this lock was taken by another, %s-safe lock in the past:\n", irqclass); print_lock_name(other); printk("\n\nand interrupts could create inverse lock ordering between them.\n\n"); -- cgit v1.2.3 From efed792d6738964f399a508ef9e831cd60fa4657 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 4 Mar 2009 12:32:55 +0100 Subject: tracing: add lockdep tracepoints for lock acquire/release Augment the traces with lock names when lockdep is available: 1) | down_read_trylock() { 1) | _spin_lock_irqsave() { 1) | /* lock_acquire: &sem->wait_lock */ 1) 4.201 us | } 1) | _spin_unlock_irqrestore() { 1) | /* lock_release: &sem->wait_lock */ 1) 3.523 us | } 1) | /* lock_acquire: try read &mm->mmap_sem */ 1) + 13.386 us | } 1) 1.635 us | find_vma(); 1) | handle_mm_fault() { 1) | __do_fault() { 1) | filemap_fault() { 1) | find_lock_page() { 1) | find_get_page() { 1) | /* lock_acquire: read rcu_read_lock */ 1) | /* lock_release: rcu_read_lock */ 1) 5.697 us | } 1) 8.158 us | } 1) + 11.079 us | } 1) | _spin_lock() { 1) | /* lock_acquire: __pte_lockptr(page) */ 1) 3.949 us | } 1) 1.460 us | page_add_file_rmap(); 1) | _spin_unlock() { 1) | /* lock_release: __pte_lockptr(page) */ 1) 3.115 us | } 1) | unlock_page() { 1) 1.421 us | page_waitqueue(); 1) 1.220 us | __wake_up_bit(); 1) 6.519 us | } 1) + 34.328 us | } 1) + 37.452 us | } 1) | up_read() { 1) | /* lock_release: &mm->mmap_sem */ 1) | _spin_lock_irqsave() { 1) | /* lock_acquire: &sem->wait_lock */ 1) 3.865 us | } 1) | _spin_unlock_irqrestore() { 1) | /* lock_release: &sem->wait_lock */ 1) 8.562 us | } 1) + 17.370 us | } Signed-off-by: Peter Zijlstra Cc: Steven Rostedt Cc: =?ISO-8859-1?Q?T=F6r=F6k?= Edwin Cc: Jason Baron Cc: Frederic Weisbecker LKML-Reference: <1236166375.5330.7209.camel@laptop> Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'kernel/lockdep.c') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 02014f7ccc8..cb70c1db85d 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -42,6 +42,7 @@ #include #include #include +#include #include @@ -2913,6 +2914,8 @@ void lock_set_class(struct lockdep_map *lock, const char *name, } EXPORT_SYMBOL_GPL(lock_set_class); +DEFINE_TRACE(lock_acquire); + /* * We are not always called with irqs disabled - do that here, * and also avoid lockdep recursion: @@ -2923,6 +2926,8 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass, { unsigned long flags; + trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip); + if (unlikely(current->lockdep_recursion)) return; @@ -2937,11 +2942,15 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass, } EXPORT_SYMBOL_GPL(lock_acquire); +DEFINE_TRACE(lock_release); + void lock_release(struct lockdep_map *lock, int nested, unsigned long ip) { unsigned long flags; + trace_lock_release(lock, nested, ip); + if (unlikely(current->lockdep_recursion)) return; @@ -3090,10 +3099,14 @@ found_it: lock->ip = ip; } +DEFINE_TRACE(lock_contended); + void lock_contended(struct lockdep_map *lock, unsigned long ip) { unsigned long flags; + trace_lock_contended(lock, ip); + if (unlikely(!lock_stat)) return; @@ -3109,10 +3122,14 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip) } EXPORT_SYMBOL_GPL(lock_contended); +DEFINE_TRACE(lock_acquired); + void lock_acquired(struct lockdep_map *lock, unsigned long ip) { unsigned long flags; + trace_lock_acquired(lock, ip); + if (unlikely(!lock_stat)) return; -- cgit v1.2.3 From 03d78913f01e8f6599823f00357ed17b32747d3d Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Thu, 5 Mar 2009 02:29:05 -0800 Subject: lockdep: remove duplicate CONFIG_DEBUG_LOCKDEP definitions Impact: cleanup The atomic debug modifiers are already defined in kernel/lockdep_internals.h. Signed-off-by: David Rientjes Acked-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/lockdep.c | 7 ------- 1 file changed, 7 deletions(-) (limited to 'kernel/lockdep.c') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 02014f7ccc8..9a1e2bcc4b8 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -433,13 +433,6 @@ atomic_t nr_find_usage_forwards_checks; atomic_t nr_find_usage_forwards_recursions; atomic_t nr_find_usage_backwards_checks; atomic_t nr_find_usage_backwards_recursions; -# define debug_atomic_inc(ptr) atomic_inc(ptr) -# define debug_atomic_dec(ptr) atomic_dec(ptr) -# define debug_atomic_read(ptr) atomic_read(ptr) -#else -# define debug_atomic_inc(ptr) do { } while (0) -# define debug_atomic_dec(ptr) do { } while (0) -# define debug_atomic_read(ptr) 0 #endif /* -- cgit v1.2.3