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/* Netfilter Driver for IPSec VPN Client
*
* Copyright(c) 2012 Samsung Electronics
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
/*
* linux_mutex.c
*
* Linux interceptor kernel mutex API implementation.
*
*/
#include "linux_internal.h"
#include "linux_mutex_internal.h"
extern SshInterceptor ssh_interceptor_context;
Boolean ssh_kernel_mutex_init(SshKernelMutex mutex)
{
spin_lock_init(&mutex->lock);
#ifdef DEBUG_LIGHT
mutex->taken = FALSE;
mutex->jiffies = 0;
#endif
return TRUE;
}
/* Allocates a simple mutex. This should be as fast as possible, but work
between different processors in a multiprocessor machine. This need
not work between different independent processes. */
SshKernelMutex
ssh_kernel_mutex_alloc(void)
{
SshKernelMutex m;
m = ssh_calloc(1, sizeof(struct SshKernelMutexRec));
if (m == NULL)
return NULL;
if (!ssh_kernel_mutex_init(m))
{
ssh_free(m);
m = NULL;
}
return m;
}
/* Frees the given mutex. The mutex must not be locked when it is
freed. */
void ssh_kernel_mutex_uninit(SshKernelMutex mutex)
{
SSH_ASSERT(!mutex->taken);
}
void ssh_kernel_mutex_free(SshKernelMutex mutex)
{
if (mutex)
{
ssh_kernel_mutex_uninit(mutex);
ssh_free(mutex);
}
}
#ifdef KERNEL_MUTEX_USE_FUNCTIONS
/* Locks the mutex. Only one thread of execution can have a mutex locked
at a time. This will block until execution can continue. One should
not keep mutexes locked for extended periods of time. */
void
ssh_kernel_mutex_lock_i(SshKernelMutex mutex)
{
SSH_LINUX_STATISTICS(ssh_interceptor_context,
{ ssh_interceptor_context->stats.num_light_locks++; });
spin_lock(&mutex->lock);
SSH_ASSERT(!mutex->taken);
#ifdef DEBUG_LIGHT
mutex->taken = TRUE;
mutex->jiffies = jiffies;
#endif /* DEBUG_LIGHT */
}
/* Unlocks the mutex. If other threads are waiting to lock the mutex,
one of them will get the lock and continue execution. */
void
ssh_kernel_mutex_unlock_i(SshKernelMutex mutex)
{
SSH_ASSERT(mutex->taken);
#ifdef DEBUG_LIGHT
mutex->taken = FALSE;
#endif /* DEBUG_LIGHT */
spin_unlock(&mutex->lock);
}
#endif /* KERNEL_MUTEX_USE_FUNCTIONS */
#ifdef DEBUG_LIGHT
/* Check that the mutex is locked. It is a fatal error if it is not. */
void
ssh_kernel_mutex_assert_is_locked(SshKernelMutex mutex)
{
SSH_ASSERT(mutex->taken);
}
#endif /* DEBUG_LIGHT */
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