mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-11-01 00:48:50 +00:00
7957f0a857
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>
65 lines
1.6 KiB
C
65 lines
1.6 KiB
C
#ifndef __LINUX_SMPLOCK_H
|
|
#define __LINUX_SMPLOCK_H
|
|
|
|
#ifdef CONFIG_LOCK_KERNEL
|
|
#include <linux/sched.h>
|
|
|
|
extern int __lockfunc __reacquire_kernel_lock(void);
|
|
extern void __lockfunc __release_kernel_lock(void);
|
|
|
|
/*
|
|
* Release/re-acquire global kernel lock for the scheduler
|
|
*/
|
|
#define release_kernel_lock(tsk) do { \
|
|
if (unlikely((tsk)->lock_depth >= 0)) \
|
|
__release_kernel_lock(); \
|
|
} while (0)
|
|
|
|
static inline int reacquire_kernel_lock(struct task_struct *task)
|
|
{
|
|
if (unlikely(task->lock_depth >= 0))
|
|
return __reacquire_kernel_lock();
|
|
return 0;
|
|
}
|
|
|
|
extern void __lockfunc
|
|
_lock_kernel(const char *func, const char *file, int line)
|
|
__acquires(kernel_lock);
|
|
|
|
extern void __lockfunc
|
|
_unlock_kernel(const char *func, const char *file, int line)
|
|
__releases(kernel_lock);
|
|
|
|
#define lock_kernel() do { \
|
|
_lock_kernel(__func__, __FILE__, __LINE__); \
|
|
} while (0)
|
|
|
|
#define unlock_kernel() do { \
|
|
_unlock_kernel(__func__, __FILE__, __LINE__); \
|
|
} while (0)
|
|
|
|
/*
|
|
* Various legacy drivers don't really need the BKL in a specific
|
|
* function, but they *do* need to know that the BKL became available.
|
|
* This function just avoids wrapping a bunch of lock/unlock pairs
|
|
* around code which doesn't really need it.
|
|
*/
|
|
static inline void cycle_kernel_lock(void)
|
|
{
|
|
lock_kernel();
|
|
unlock_kernel();
|
|
}
|
|
|
|
#else
|
|
|
|
#ifdef CONFIG_BKL /* provoke build bug if not set */
|
|
#define lock_kernel()
|
|
#define unlock_kernel()
|
|
#define cycle_kernel_lock() do { } while(0)
|
|
#endif /* CONFIG_BKL */
|
|
|
|
#define release_kernel_lock(task) do { } while(0)
|
|
#define reacquire_kernel_lock(task) 0
|
|
|
|
#endif /* CONFIG_LOCK_KERNEL */
|
|
#endif /* __LINUX_SMPLOCK_H */
|