forked from Qortal/Brooklyn
2a709f28fa
* 0day explit mitigation * Memory corruption prevention * Privilege escalation prevention * Buffer over flow prevention * File System corruption defense * Thread escape prevention This may very well be the most intensive inclusion to BrooklynR. This will not be part of an x86 suite nor it will be released as tool kit. The security core toolkit will remain part of kernel base.
101 lines
2.3 KiB
C
101 lines
2.3 KiB
C
#ifndef __LINUX_BIT_SPINLOCK_H
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#define __LINUX_BIT_SPINLOCK_H
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#include <linux/kernel.h>
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#include <linux/preempt.h>
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#include <linux/atomic.h>
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#include <linux/bug.h>
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/*
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* bit-based spin_lock()
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*
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* Don't use this unless you really need to: spin_lock() and spin_unlock()
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* are significantly faster.
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*/
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static inline void bit_spin_lock(int bitnum, unsigned long *addr)
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{
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/*
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* Assuming the lock is uncontended, this never enters
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* the body of the outer loop. If it is contended, then
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* within the inner loop a non-atomic test is used to
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* busywait with less bus contention for a good time to
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* attempt to acquire the lock bit.
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*/
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preempt_disable();
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#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
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while (unlikely(test_and_set_bit_lock(bitnum, addr))) {
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preempt_enable();
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do {
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cpu_relax();
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} while (test_bit(bitnum, addr));
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preempt_disable();
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}
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#endif
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__acquire(bitlock);
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}
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/*
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* Return true if it was acquired
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*/
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static inline int bit_spin_trylock(int bitnum, unsigned long *addr)
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{
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preempt_disable();
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#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
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if (unlikely(test_and_set_bit_lock(bitnum, addr))) {
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preempt_enable();
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return 0;
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}
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#endif
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__acquire(bitlock);
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return 1;
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}
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/*
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* bit-based spin_unlock()
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*/
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static inline void bit_spin_unlock(int bitnum, unsigned long *addr)
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{
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#ifdef CONFIG_DEBUG_SPINLOCK
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BUG_ON(!test_bit(bitnum, addr));
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#endif
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#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
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clear_bit_unlock(bitnum, addr);
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#endif
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preempt_enable();
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__release(bitlock);
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}
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/*
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* bit-based spin_unlock()
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* non-atomic version, which can be used eg. if the bit lock itself is
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* protecting the rest of the flags in the word.
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*/
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static inline void __bit_spin_unlock(int bitnum, unsigned long *addr)
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{
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#ifdef CONFIG_DEBUG_SPINLOCK
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BUG_ON(!test_bit(bitnum, addr));
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#endif
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#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
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__clear_bit_unlock(bitnum, addr);
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#endif
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preempt_enable();
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__release(bitlock);
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}
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/*
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* Return true if the lock is held.
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*/
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static inline int bit_spin_is_locked(int bitnum, unsigned long *addr)
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{
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#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
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return test_bit(bitnum, addr);
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#elif defined CONFIG_PREEMPT_COUNT
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return preempt_count();
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#else
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return 1;
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#endif
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}
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#endif /* __LINUX_BIT_SPINLOCK_H */
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