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Commit e0ed1c22 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

Pull locking fixes from Ingo Molnar:
 "Two fixes:

   - a file locks fix (missing critical section, bug introduced in this
     merge window)

   - an x86 down_write() stack frame annotation"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking, fs/locks: Add missing file_sem locks
  locking/rwsem/x86: Add stack frame dependency for ____down_write()
parents 50276c9a 5f43086b

arch/x86/include/asm/rwsem.h

+4 −2
Original line number Diff line number Diff line
@@ -103,8 +103,10 @@ static inline bool __down_read_trylock(struct rw_semaphore *sem) 
({							\

	long tmp;					\

	struct rw_semaphore* ret;			\

	register void *__sp asm(_ASM_SP);		\

							\

	asm volatile("# beginning down_write\n\t"	\

		     LOCK_PREFIX "  xadd      %1,(%3)\n\t"	\

		     LOCK_PREFIX "  xadd      %1,(%4)\n\t"	\

		     /* adds 0xffff0001, returns the old value */ \

		     "  test " __ASM_SEL(%w1,%k1) "," __ASM_SEL(%w1,%k1) "\n\t" \

		     /* was the active mask 0 before? */\
@@ -112,7 +114,7 @@ static inline bool __down_read_trylock(struct rw_semaphore *sem) 
		     "  call " slow_path "\n"		\

		     "1:\n"				\

		     "# ending down_write"		\

		     : "+m" (sem->count), "=d" (tmp), "=a" (ret)	\

		     : "+m" (sem->count), "=d" (tmp), "=a" (ret), "+r" (__sp) \

		     : "a" (sem), "1" (RWSEM_ACTIVE_WRITE_BIAS) \

		     : "memory", "cc");			\

	ret;						\

fs/locks.c

+6 −0
Original line number Diff line number Diff line
@@ -1609,6 +1609,7 @@ int fcntl_getlease(struct file *filp) 


	ctx = smp_load_acquire(&inode->i_flctx);

	if (ctx && !list_empty_careful(&ctx->flc_lease)) {

		percpu_down_read_preempt_disable(&file_rwsem);

		spin_lock(&ctx->flc_lock);

		time_out_leases(inode, &dispose);

		list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
@@ -1618,6 +1619,8 @@ int fcntl_getlease(struct file *filp) 
			break;

		}

		spin_unlock(&ctx->flc_lock);

		percpu_up_read_preempt_enable(&file_rwsem);



		locks_dispose_list(&dispose);

	}

	return type;
@@ -2529,11 +2532,14 @@ locks_remove_lease(struct file *filp, struct file_lock_context *ctx) 
	if (list_empty(&ctx->flc_lease))

		return;



	percpu_down_read_preempt_disable(&file_rwsem);

	spin_lock(&ctx->flc_lock);

	list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list)

		if (filp == fl->fl_file)

			lease_modify(fl, F_UNLCK, &dispose);

	spin_unlock(&ctx->flc_lock);

	percpu_up_read_preempt_enable(&file_rwsem);



	locks_dispose_list(&dispose);

}