/*
 * 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/spinlock.h>
#include <linux/nmi.h>
#include <linux/interrupt.h>
#include <linux/debug_locks.h>
#include <linux/delay.h>
#include <linux/export.h>

void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
			  struct lock_class_key *key)
{
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	/*
	 * Make sure we are not reinitializing a held lock:
	 */
	debug_check_no_locks_freed((void *)lock, sizeof(*lock));
	lockdep_init_map(&lock->dep_map, name, key, 0);
#endif
	lock->raw_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
	lock->magic = SPINLOCK_MAGIC;
	lock->owner = SPINLOCK_OWNER_INIT;
	lock->owner_cpu = -1;
}

EXPORT_SYMBOL(__raw_spin_lock_init);

void __rwlock_init(rwlock_t *lock, const char *name,
		   struct lock_class_key *key)
{
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	/*
	 * Make sure we are not reinitializing a held lock:
	 */
	debug_check_no_locks_freed((void *)lock, sizeof(*lock));
	lockdep_init_map(&lock->dep_map, name, key, 0);
#endif
	lock->raw_lock = (arch_rwlock_t) __ARCH_RW_LOCK_UNLOCKED;
	lock->magic = RWLOCK_MAGIC;
	lock->owner = SPINLOCK_OWNER_INIT;
	lock->owner_cpu = -1;
}

EXPORT_SYMBOL(__rwlock_init);

static void spin_dump(raw_spinlock_t *lock, const char *msg)
{
	struct task_struct *owner = NULL;

	if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT)
		owner = lock->owner;
	printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n",
		msg, raw_smp_processor_id(),
		current->comm, task_pid_nr(current));
	printk(KERN_EMERG " lock: %pS, .magic: %08x, .owner: %s/%d, "
			".owner_cpu: %d\n",
		lock, lock->magic,
		owner ? owner->comm : "<none>",
		owner ? task_pid_nr(owner) : -1,
		lock->owner_cpu);
	dump_stack();
}

static void spin_bug(raw_spinlock_t *lock, const char *msg)
{
	if (!debug_locks_off())
		return;

	spin_dump(lock, msg);
}

#define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg)

static inline void
debug_spin_lock_before(raw_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(raw_spinlock_t *lock)
{
	lock->owner_cpu = raw_smp_processor_id();
	lock->owner = current;
}

static inline void debug_spin_unlock(raw_spinlock_t *lock)
{
	SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");
	SPIN_BUG_ON(!raw_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(raw_spinlock_t *lock)
{
	u64 i;
	u64 loops = loops_per_jiffy * HZ;

	for (i = 0; i < loops; i++) {
		if (arch_spin_trylock(&lock->raw_lock))
			return;
		__delay(1);
	}
	/* lockup suspected: */
	spin_dump(lock, "lockup suspected");
#ifdef CONFIG_SMP
	trigger_all_cpu_backtrace();
#endif

	/*
	 * The trylock above was causing a livelock.  Give the lower level arch
	 * specific lock code a chance to acquire the lock. We have already
	 * printed a warning/backtrace at this point. The non-debug arch
	 * specific code might actually succeed in acquiring the lock.  If it is
	 * not successful, the end-result is the same - there is no forward
	 * progress.
	 */
	arch_spin_lock(&lock->raw_lock);
}

void do_raw_spin_lock(raw_spinlock_t *lock)
{
	debug_spin_lock_before(lock);
	if (unlikely(!arch_spin_trylock(&lock->raw_lock)))
		__spin_lock_debug(lock);
	debug_spin_lock_after(lock);
}

int do_raw_spin_trylock(raw_spinlock_t *lock)
{
	int ret = arch_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 do_raw_spin_unlock(raw_spinlock_t *lock)
{
	debug_spin_unlock(lock);
	arch_spin_unlock(&lock->raw_lock);
}

static void rwlock_bug(rwlock_t *lock, const char *msg)
{
	if (!debug_locks_off())
		return;

	printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n",
		msg, raw_smp_processor_id(), current->comm,
		task_pid_nr(current), lock);
	dump_stack();
}

#define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg)

#if 0		/* __write_lock_debug() can lock up - maybe this can too? */
static void __read_lock_debug(rwlock_t *lock)
{
	u64 i;
	u64 loops = loops_per_jiffy * HZ;
	int print_once = 1;

	for (;;) {
		for (i = 0; i < loops; i++) {
			if (arch_read_trylock(&lock->raw_lock))
				return;
			__delay(1);
		}
		/* lockup suspected: */
		if (print_once) {
			print_once = 0;
			printk(KERN_EMERG "BUG: read-lock lockup on CPU#%d, "
					"%s/%d, %p\n",
				raw_smp_processor_id(), current->comm,
				current->pid, lock);
			dump_stack();
		}
	}
}
#endif

void do_raw_read_lock(rwlock_t *lock)
{
	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
	arch_read_lock(&lock->raw_lock);
}

int do_raw_read_trylock(rwlock_t *lock)
{
	int ret = arch_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 do_raw_read_unlock(rwlock_t *lock)
{
	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
	arch_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;
}

#if 0		/* This can cause lockups */
static void __write_lock_debug(rwlock_t *lock)
{
	u64 i;
	u64 loops = loops_per_jiffy * HZ;
	int print_once = 1;

	for (;;) {
		for (i = 0; i < loops; i++) {
			if (arch_write_trylock(&lock->raw_lock))
				return;
			__delay(1);
		}
		/* lockup suspected: */
		if (print_once) {
			print_once = 0;
			printk(KERN_EMERG "BUG: write-lock lockup on CPU#%d, "
					"%s/%d, %p\n",
				raw_smp_processor_id(), current->comm,
				current->pid, lock);
			dump_stack();
		}
	}
}
#endif

void do_raw_write_lock(rwlock_t *lock)
{
	debug_write_lock_before(lock);
	arch_write_lock(&lock->raw_lock);
	debug_write_lock_after(lock);
}

int do_raw_write_trylock(rwlock_t *lock)
{
	int ret = arch_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 do_raw_write_unlock(rwlock_t *lock)
{
	debug_write_unlock(lock);
	arch_write_unlock(&lock->raw_lock);
}

    from Eric Dumazet.

 7) Fix RTNL deadlock wrt. lwtunnel module loading, from David Ahern.

 8) tcp_fastopen_create_child() needs to setup tp-&gt;max_window, from
    Alexey Kodanev.

 9) Missing kmemdup() failure check in ipv6 segment routing code, from
    Eric Dumazet.

10) Don't execute unix_bind() under the bindlock, otherwise we deadlock
    with splice. From WANG Cong.

11) ip6_tnl_parse_tlv_enc_lim() potentially reallocates the skb buffer,
    therefore callers must reload cached header pointers into that skb.
    Fix from Eric Dumazet.

12) Fix various bugs in legacy IRQ fallback handling in alx driver, from
    Tobias Regnery.

13) Do not allow lwtunnel drivers to be unloaded while they are
    referenced by active instances, from Robert Shearman.

14) Fix truncated PHY LED trigger names, from Geert Uytterhoeven.

15) Fix a few regressions from virtio_net XDP support, from John
    Fastabend and Jakub Kicinski.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (102 commits)
  ISDN: eicon: silence misleading array-bounds warning
  net: phy: micrel: add support for KSZ8795
  gtp: fix cross netns recv on gtp socket
  gtp: clear DF bit on GTP packet tx
  gtp: add genl family modules alias
  tcp: don't annotate mark on control socket from tcp_v6_send_response()
  ravb: unmap descriptors when freeing rings
  virtio_net: reject XDP programs using header adjustment
  virtio_net: use dev_kfree_skb for small buffer XDP receive
  r8152: check rx after napi is enabled
  r8152: re-schedule napi for tx
  r8152: avoid start_xmit to schedule napi when napi is disabled
  r8152: avoid start_xmit to call napi_schedule during autosuspend
  net: dsa: Bring back device detaching in dsa_slave_suspend()
  net: phy: leds: Fix truncated LED trigger names
  net: phy: leds: Break dependency of phy.h on phy_led_triggers.h
  net: phy: leds: Clear phy_num_led_triggers on failure to avoid crash
  net-next: ethernet: mediatek: change the compatible string
  Documentation: devicetree: change the mediatek ethernet compatible string
  bnxt_en: Fix RTNL lock usage on bnxt_get_port_module_status().
  ...
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>Diffstat</a> (limited to 'tools/perf/Documentation/perf-list.txt')</div><table summary='diffstat' class='diffstat'>