--- /dev/null
+/*
+ * Copyright 2005, Red Hat, Inc., Ingo Molnar
+ * Released under the General Public License (GPL).
+ *
+ * This file contains the spinlock/rwlock implementations for
+ * DEBUG_SPINLOCK.
+ */
+
+#include <linux/config.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+
+int nopanic;
+static int __init nopanic_setup(char *str)
+{
+ nopanic = 1;
+ return 1;
+}
+EXPORT_SYMBOL_GPL(nopanic);
+__setup("dontpanic", nopanic_setup);
+
+
+static void spin_bug(spinlock_t *lock, const char *msg)
+{
+ static long print_once = 1;
+ struct task_struct *owner = NULL;
+
+ if (xchg(&print_once, 0)) {
+ if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT)
+ owner = lock->owner;
+ printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d (%s)\n",
+ msg, raw_smp_processor_id(),
+ current->comm, current->pid, print_tainted());
+ printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, "
+ ".owner_cpu: %d\n",
+ lock, lock->magic,
+ owner ? owner->comm : "<none>",
+ owner ? owner->pid : -1,
+ lock->owner_cpu);
+ dump_stack();
+#ifdef CONFIG_SMP
+ /*
+ * We cannot continue on SMP:
+ */
+ if (nopanic)
+ printk("bad locking\n");
+ else
+ panic("bad locking");
+#endif
+ }
+}
+
+#define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg)
+
+static inline void debug_spin_lock_before(spinlock_t *lock)
+{
+ SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");
+ SPIN_BUG_ON(lock->owner == current, lock, "recursion");
+ SPIN_BUG_ON(lock->owner_cpu == raw_smp_processor_id(),
+ lock, "cpu recursion");
+}
+
+static inline void debug_spin_lock_after(spinlock_t *lock)
+{
+ lock->owner_cpu = raw_smp_processor_id();
+ lock->owner = current;
+}
+
+static inline void debug_spin_unlock(spinlock_t *lock)
+{
+ SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");
+ SPIN_BUG_ON(!spin_is_locked(lock), lock, "already unlocked");
+ SPIN_BUG_ON(lock->owner != current, lock, "wrong owner");
+ SPIN_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
+ lock, "wrong CPU");
+ lock->owner = SPINLOCK_OWNER_INIT;
+ lock->owner_cpu = -1;
+}
+
+static void __spin_lock_debug(spinlock_t *lock)
+{
+ int print_once = 1;
+ u64 i;
+
+ for (;;) {
+ for (i = 0; i < loops_per_jiffy * HZ; i++) {
+ if (__raw_spin_trylock(&lock->raw_lock))
+ return;
+ }
+ /* lockup suspected: */
+ if (print_once) {
+ print_once = 0;
+ printk(KERN_EMERG "BUG: spinlock lockup on CPU#%d, "
+ "%s/%d, %p (%s)\n",
+ raw_smp_processor_id(), current->comm,
+ current->pid, lock, print_tainted());
+ dump_stack();
+ }
+ }
+}
+
+void _raw_spin_lock(spinlock_t *lock)
+{
+ debug_spin_lock_before(lock);
+ if (unlikely(!__raw_spin_trylock(&lock->raw_lock)))
+ __spin_lock_debug(lock);
+ debug_spin_lock_after(lock);
+}
+
+int _raw_spin_trylock(spinlock_t *lock)
+{
+ int ret = __raw_spin_trylock(&lock->raw_lock);
+
+ if (ret)
+ debug_spin_lock_after(lock);
+#ifndef CONFIG_SMP
+ /*
+ * Must not happen on UP:
+ */
+ SPIN_BUG_ON(!ret, lock, "trylock failure on UP");
+#endif
+ return ret;
+}
+
+void _raw_spin_unlock(spinlock_t *lock)
+{
+ debug_spin_unlock(lock);
+ __raw_spin_unlock(&lock->raw_lock);
+}
+
+static void rwlock_bug(rwlock_t *lock, const char *msg)
+{
+ static long print_once = 1;
+
+ if (xchg(&print_once, 0)) {
+ printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p (%s)\n",
+ msg, raw_smp_processor_id(), current->comm,
+ current->pid, lock, print_tainted());
+ dump_stack();
+#ifdef CONFIG_SMP
+ /*
+ * We cannot continue on SMP:
+ */
+ panic("bad locking");
+#endif
+ }
+}
+
+#define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg)
+
+static void __read_lock_debug(rwlock_t *lock)
+{
+ int print_once = 1;
+ u64 i;
+
+ for (;;) {
+ for (i = 0; i < loops_per_jiffy * HZ; i++) {
+ if (__raw_read_trylock(&lock->raw_lock))
+ return;
+ }
+ /* lockup suspected: */
+ if (print_once) {
+ print_once = 0;
+ printk(KERN_EMERG "BUG: read-lock lockup on CPU#%d, "
+ "%s/%d, %p (%s)\n",
+ raw_smp_processor_id(), current->comm,
+ current->pid, lock, print_tainted());
+ dump_stack();
+ }
+ }
+}
+
+void _raw_read_lock(rwlock_t *lock)
+{
+ RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
+ if (unlikely(!__raw_read_trylock(&lock->raw_lock)))
+ __read_lock_debug(lock);
+}
+
+int _raw_read_trylock(rwlock_t *lock)
+{
+ int ret = __raw_read_trylock(&lock->raw_lock);
+
+#ifndef CONFIG_SMP
+ /*
+ * Must not happen on UP:
+ */
+ RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP");
+#endif
+ return ret;
+}
+
+void _raw_read_unlock(rwlock_t *lock)
+{
+ RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
+ __raw_read_unlock(&lock->raw_lock);
+}
+
+static inline void debug_write_lock_before(rwlock_t *lock)
+{
+ RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
+ RWLOCK_BUG_ON(lock->owner == current, lock, "recursion");
+ RWLOCK_BUG_ON(lock->owner_cpu == raw_smp_processor_id(),
+ lock, "cpu recursion");
+}
+
+static inline void debug_write_lock_after(rwlock_t *lock)
+{
+ lock->owner_cpu = raw_smp_processor_id();
+ lock->owner = current;
+}
+
+static inline void debug_write_unlock(rwlock_t *lock)
+{
+ RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
+ RWLOCK_BUG_ON(lock->owner != current, lock, "wrong owner");
+ RWLOCK_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
+ lock, "wrong CPU");
+ lock->owner = SPINLOCK_OWNER_INIT;
+ lock->owner_cpu = -1;
+}
+
+static void __write_lock_debug(rwlock_t *lock)
+{
+ int print_once = 1;
+ u64 i;
+
+ for (;;) {
+ for (i = 0; i < loops_per_jiffy * HZ; i++) {
+ if (__raw_write_trylock(&lock->raw_lock))
+ return;
+ }
+ /* lockup suspected: */
+ if (print_once) {
+ print_once = 0;
+ printk(KERN_EMERG "BUG: write-lock lockup on CPU#%d, "
+ "%s/%d, %p (%s)\n",
+ raw_smp_processor_id(), current->comm,
+ current->pid, lock, print_tainted());
+ dump_stack();
+ }
+ }
+}
+
+void _raw_write_lock(rwlock_t *lock)
+{
+ debug_write_lock_before(lock);
+ if (unlikely(!__raw_write_trylock(&lock->raw_lock)))
+ __write_lock_debug(lock);
+ debug_write_lock_after(lock);
+}
+
+int _raw_write_trylock(rwlock_t *lock)
+{
+ int ret = __raw_write_trylock(&lock->raw_lock);
+
+ if (ret)
+ debug_write_lock_after(lock);
+#ifndef CONFIG_SMP
+ /*
+ * Must not happen on UP:
+ */
+ RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP");
+#endif
+ return ret;
+}
+
+void _raw_write_unlock(rwlock_t *lock)
+{
+ debug_write_unlock(lock);
+ __raw_write_unlock(&lock->raw_lock);
+}
git://git.onelab.eu / linux-2.6.git / blobdiff