alloc.c

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#ifndef _ALLOC_C_
#define _ALLOC_C_

/* -*- linux-c -*- */
/** @file alloc.c
 * @brief Memory functions.
 */
/** @addtogroup alloc Memory Functions
 * Basic malloc/calloc/free functions. These will be changed so 
 * that memory allocation errors will call a handler.  The default will
 * send a signal to the user-space daemon that will trigger the module to
 * be unloaded.
 * @todo Need error handling for memory allocations
 * @todo Some of these currently use kmalloc (GFP_ATOMIC) for
 * small allocations.  This should be evaluated for performance
 * and stability.
 * @{
 */

enum errorcode { ERR_NONE=0, ERR_NO_MEM };
enum errorcode _stp_error = ERR_NONE;

/** Allocates memory within a probe.
 * This is used for small allocations from within a running
 * probe where the process cannot sleep. 
 * @param len Number of bytes to allocate.
 * @return a valid pointer on success or NULL on failure.
 * @bug Currently uses kmalloc (GFP_ATOMIC).
 */

void *_stp_alloc(size_t len)
{
        void *ptr = kmalloc(len, GFP_ATOMIC);
        if (unlikely(ptr == NULL))
                _stp_error = ERR_NO_MEM;
        return ptr;
}

/** Allocates and clears memory within a probe.
 * This is used for small allocations from within a running
 * probe where the process cannot sleep. 
 * @param len Number of bytes to allocate.
 * @return a valid pointer on success or NULL on failure.
 * @bug Currently uses kmalloc (GFP_ATOMIC).
 */

void *_stp_calloc(size_t len)
{
        void *ptr = _stp_alloc(len);
        if (likely(ptr))
                memset(ptr, 0, len);
        return ptr;
}

/** Allocates and clears memory outside a probe.
 * This is typically used in the module initialization to
 * allocate new maps, lists, etc.
 * @param len Number of bytes to allocate.
 * @return a valid pointer on success or NULL on failure.
 */

void *_stp_valloc(size_t len)
{
        void *ptr = vmalloc(len);
        if (likely(ptr))
                memset(ptr, 0, len);
        else
                _stp_error = ERR_NO_MEM;
        return ptr;
}

/** Frees memory allocated by _stp_alloc or _stp_calloc.
 * @param ptr pointer to memory to free
 */

void _stp_free(void *ptr)
{
        if (likely(ptr))
                kfree(ptr);
}

/** Frees memory allocated by _stp_valloc.
 * @param ptr pointer to memory to free
 */

void _stp_vfree(void *ptr)
{
        if (likely(ptr))
                vfree(ptr);
}

/** @} */
#endif /* _ALLOC_C_ */