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Commit 7b367f5d authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull core kernel fixes from Ingo Molnar:
 "This contains the nohz/atomic cleanup/fix for the fetch_or() ugliness
  you noted during the original nohz pull request, plus there's also
  misc fixes:

   - fix liblockdep build bug
   - fix uapi header build bug
   - print more lockdep hash collision info to help debug recent reports
     of hash collisions
   - update MAINTAINERS email address"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Update my email address
  locking/lockdep: Print chain_key collision information
  uapi/linux/stddef.h: Provide __always_inline to userspace headers
  tools/lib/lockdep: Fix unsupported 'basename -s' in run_tests.sh
  locking/atomic, sched: Unexport fetch_or()
  timers/nohz: Convert tick dependency mask to atomic_t
  locking/atomic: Introduce atomic_fetch_or()
parents 17084b7e 353def94

MAINTAINERS

+1 −1
Original line number Original line Diff line number Diff line
@@ -6403,7 +6403,7 @@ KPROBES 
M:	Ananth N Mavinakayanahalli <ananth@in.ibm.com>

M:	Ananth N Mavinakayanahalli <ananth@in.ibm.com>

M:	Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>

M:	Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>

M:	"David S. Miller" <davem@davemloft.net>

M:	"David S. Miller" <davem@davemloft.net>

M:	Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

M:	Masami Hiramatsu <mhiramat@kernel.org>

S:	Maintained

S:	Maintained

F:	Documentation/kprobes.txt

F:	Documentation/kprobes.txt

F:	include/linux/kprobes.h

F:	include/linux/kprobes.h

include/linux/atomic.h

+17 −17
Original line number Original line Diff line number Diff line
@@ -559,25 +559,25 @@ static inline int atomic_dec_if_positive(atomic_t *v) 
#endif

#endif





/**

/**

 * fetch_or - perform *ptr |= mask and return old value of *ptr

 * atomic_fetch_or - perform *p |= mask and return old value of *p

 * @ptr: pointer to value

 * @p: pointer to atomic_t

 * @mask: mask to OR on the value

 * @mask: mask to OR on the atomic_t

 *

 * cmpxchg based fetch_or, macro so it works for different integer types

 */

 */

#ifndef fetch_or

#ifndef atomic_fetch_or

#define fetch_or(ptr, mask)						\

static inline int atomic_fetch_or(atomic_t *p, int mask)

({	typeof(*(ptr)) __old, __val = *(ptr);				\

{

	for (;;) {							\

	int old, val = atomic_read(p);

		__old = cmpxchg((ptr), __val, __val | (mask));		\



		if (__old == __val)					\

	for (;;) {

			break;						\

		old = atomic_cmpxchg(p, val, val | mask);

		__val = __old;						\

		if (old == val)

	}								\

			break;

	__old;								\

		val = old;

})

	}

#endif





	return old;

}

#endif





#ifdef CONFIG_GENERIC_ATOMIC64

#ifdef CONFIG_GENERIC_ATOMIC64

#include <asm-generic/atomic64.h>

#include <asm-generic/atomic64.h>

include/linux/sched.h

+2 −2
Original line number Original line Diff line number Diff line
@@ -720,7 +720,7 @@ struct signal_struct { 
	struct task_cputime cputime_expires;

	struct task_cputime cputime_expires;





#ifdef CONFIG_NO_HZ_FULL

#ifdef CONFIG_NO_HZ_FULL

	unsigned long tick_dep_mask;

	atomic_t tick_dep_mask;

#endif

#endif





	struct list_head cpu_timers[3];

	struct list_head cpu_timers[3];
@@ -1549,7 +1549,7 @@ struct task_struct { 
#endif

#endif





#ifdef CONFIG_NO_HZ_FULL

#ifdef CONFIG_NO_HZ_FULL

	unsigned long tick_dep_mask;

	atomic_t tick_dep_mask;

#endif

#endif

	unsigned long nvcsw, nivcsw; /* context switch counts */

	unsigned long nvcsw, nivcsw; /* context switch counts */

	u64 start_time;		/* monotonic time in nsec */

	u64 start_time;		/* monotonic time in nsec */

include/uapi/linux/stddef.h

+4 −0
Original line number Original line Diff line number Diff line 
#include <linux/compiler.h>

#include <linux/compiler.h>



#ifndef __always_inline

#define __always_inline inline

#endif

kernel/locking/lockdep.c

+77 −2
Original line number Original line Diff line number Diff line
@@ -1999,6 +1999,77 @@ static inline int get_first_held_lock(struct task_struct *curr, 
	return ++i;

	return ++i;

}

}





/*

 * Returns the next chain_key iteration

 */

static u64 print_chain_key_iteration(int class_idx, u64 chain_key)

{

	u64 new_chain_key = iterate_chain_key(chain_key, class_idx);



	printk(" class_idx:%d -> chain_key:%016Lx",

		class_idx,

		(unsigned long long)new_chain_key);

	return new_chain_key;

}



static void

print_chain_keys_held_locks(struct task_struct *curr, struct held_lock *hlock_next)

{

	struct held_lock *hlock;

	u64 chain_key = 0;

	int depth = curr->lockdep_depth;

	int i;



	printk("depth: %u\n", depth + 1);

	for (i = get_first_held_lock(curr, hlock_next); i < depth; i++) {

		hlock = curr->held_locks + i;

		chain_key = print_chain_key_iteration(hlock->class_idx, chain_key);



		print_lock(hlock);

	}



	print_chain_key_iteration(hlock_next->class_idx, chain_key);

	print_lock(hlock_next);

}



static void print_chain_keys_chain(struct lock_chain *chain)

{

	int i;

	u64 chain_key = 0;

	int class_id;



	printk("depth: %u\n", chain->depth);

	for (i = 0; i < chain->depth; i++) {

		class_id = chain_hlocks[chain->base + i];

		chain_key = print_chain_key_iteration(class_id + 1, chain_key);



		print_lock_name(lock_classes + class_id);

		printk("\n");

	}

}



static void print_collision(struct task_struct *curr,

			struct held_lock *hlock_next,

			struct lock_chain *chain)

{

	printk("\n");

	printk("======================\n");

	printk("[chain_key collision ]\n");

	print_kernel_ident();

	printk("----------------------\n");

	printk("%s/%d: ", current->comm, task_pid_nr(current));

	printk("Hash chain already cached but the contents don't match!\n");



	printk("Held locks:");

	print_chain_keys_held_locks(curr, hlock_next);



	printk("Locks in cached chain:");

	print_chain_keys_chain(chain);



	printk("\nstack backtrace:\n");

	dump_stack();

}



/*

/*

 * Checks whether the chain and the current held locks are consistent

 * Checks whether the chain and the current held locks are consistent

 * in depth and also in content. If they are not it most likely means

 * in depth and also in content. If they are not it most likely means
@@ -2014,15 +2085,19 @@ static int check_no_collision(struct task_struct *curr, 




	i = get_first_held_lock(curr, hlock);

	i = get_first_held_lock(curr, hlock);





	if (DEBUG_LOCKS_WARN_ON(chain->depth != curr->lockdep_depth - (i - 1)))

	if (DEBUG_LOCKS_WARN_ON(chain->depth != curr->lockdep_depth - (i - 1))) {

		print_collision(curr, hlock, chain);

		return 0;

		return 0;

	}





	for (j = 0; j < chain->depth - 1; j++, i++) {

	for (j = 0; j < chain->depth - 1; j++, i++) {

		id = curr->held_locks[i].class_idx - 1;

		id = curr->held_locks[i].class_idx - 1;





		if (DEBUG_LOCKS_WARN_ON(chain_hlocks[chain->base + j] != id))

		if (DEBUG_LOCKS_WARN_ON(chain_hlocks[chain->base + j] != id)) {

			print_collision(curr, hlock, chain);

			return 0;

			return 0;

		}

		}

	}

#endif

#endif

	return 1;

	return 1;

}

}