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