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Fix build failure due to hwirq.h needing smp_lock.h 

Arnd Bergmann did an automated scripting run to find left-over instances
of <linux/smp_lock.h>, and had made it trigger it on the normal BKL use
of lock_kernel and unlock_lernel (and apparently release_kernel_lock and
reacquire_kernel_lock too, used by the scheduler).

That resulted in commit 451a3c24b0 ("BKL: remove extraneous #include
<smp_lock.h>").

However, hardirq.h was the only remaining user of the old
'kernel_locked()' interface, and Arnd's script hadn't checked for that.
So depending on your configuration and what header files had been
included, you would get errors like "implicit declaration of function
'kernel_locked'" during the build.

The right fix is not to just re-instate the smp_lock.h include - it is
to just remove 'kernel_locked()' entirely, since the only use was this
one special low-level detail.  Just make hardirq.h do it directly.

In fact this simplifies and clarifies the code, because some trivial
analysis makes it clear that hardirq.h only ever used _one_ of the two
definitions of kernel_locked(), so we can remove the other one entirely.

Reported-by: Zimny Lech <napohybelskurwysynom2010@gmail.com>
Reported-and-acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2010-11-17 14:58:36 -08:00
parent 460781b542
commit 7957f0a857
2 changed files with 1 additions and 4 deletions
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2
include/linux/hardirq.h
View File

@ -96,7 +96,7 @@
#define in_nmi() (preempt_count() & NMI_MASK)
#if defined(CONFIG_PREEMPT) && defined(CONFIG_BKL)
# define PREEMPT_INATOMIC_BASE kernel_locked()
# define PREEMPT_INATOMIC_BASE (current->lock_depth >= 0)
#else
# define PREEMPT_INATOMIC_BASE 0
#endif

3
include/linux/smp_lock.h
View File

@ -4,8 +4,6 @@
#ifdef CONFIG_LOCK_KERNEL
#include <linux/sched.h>
#define kernel_locked() (current->lock_depth >= 0)
extern int __lockfunc __reacquire_kernel_lock(void);
extern void __lockfunc __release_kernel_lock(void);
@ -58,7 +56,6 @@ static inline void cycle_kernel_lock(void)
#define lock_kernel()
#define unlock_kernel()
#define cycle_kernel_lock() do { } while(0)
#define kernel_locked() 1
#endif /* CONFIG_BKL */
#define release_kernel_lock(task) do { } while(0)