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/* -*- linux-c -*-
* Memory allocation functions
* Copyright (C) 2005 Red Hat Inc.
*
* This file is part of systemtap, and is free software. You can
* redistribute it and/or modify it under the terms of the GNU General
* Public License (GPL); either version 2, or (at your option) any
* later version.
*/
#ifndef _ALLOC_C_
#define _ALLOC_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.
* @{
*/
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15)
/**
* vmalloc_node - allocate virtually contiguous memory
*
* @size: allocation size
* @node: preferred node
*
* This vmalloc variant try to allocate memory from a preferred node.
* This code is from Eric Dumazet, posted to the LKML.
* FIXME: The version in the mm kernel is different. Should probably
* switch if is is easily backported.
*/
#ifdef CONFIG_NUMA
/* Until we get something working */
#define vmalloc_node(size,node) vmalloc(size)
#else
#define vmalloc_node(size,node) vmalloc(size)
#endif /* CONFIG_NUMA */
#endif /* LINUX_VERSION_CODE */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,12)
#define kmalloc_node(size,flags,node) kmalloc(size,flags)
#endif /* LINUX_VERSION_CODE */
/** 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.
* @note Not currently used by the runtime. Deprecate?
*/
void *_stp_alloc(size_t len)
{
void *ptr = kmalloc(len, GFP_ATOMIC);
if (unlikely(ptr == NULL))
_stp_error("_stp_alloc failed.\n");
return ptr;
}
void *_stp_alloc_cpu(size_t len, int cpu)
{
void *ptr = kmalloc_node(len, GFP_ATOMIC, cpu_to_node(cpu));
if (unlikely(ptr == NULL))
_stp_error("_stp_alloc failed.\n");
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.
* @note Not currently used by the runtime. Deprecate?
*/
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("_stp_valloc failed.\n");
return ptr;
}
void *_stp_valloc_cpu(size_t len, int cpu)
{
void *ptr = vmalloc_node(len, cpu_to_node(cpu));
if (likely(ptr))
memset(ptr, 0, len);
else
_stp_error("_stp_valloc failed.\n");
return ptr;
}
struct _stp_percpu_data {
void *ptrs[NR_CPUS];
void *data;
};
#ifdef CONFIG_SMP
/**
* __stp_valloc_percpu - allocate one copy of the object for every present
* cpu in the system, using vmalloc and zeroing them.
* Objects should be dereferenced using the per_cpu_ptr macro only.
*
* @size: how many bytes of memory are required.
* @align: the alignment, which can't be greater than SMP_CACHE_BYTES.
*/
static void *__stp_valloc_percpu(size_t size, size_t align)
{
int i;
struct _stp_percpu_data *pdata = kmalloc(sizeof (*pdata), GFP_KERNEL);
if (!pdata)
return NULL;
for (i = 0; i < NR_CPUS; i++) {
if (!cpu_possible(i))
continue;
pdata->ptrs[i] = vmalloc_node(size, cpu_to_node(i));
if (!pdata->ptrs[i])
goto unwind_oom;
memset(pdata->ptrs[i], 0, size);
}
/* Catch derefs w/o wrappers */
return (void *) (~(unsigned long) pdata);
unwind_oom:
while (--i >= 0) {
if (!cpu_possible(i))
continue;
vfree(pdata->ptrs[i]);
}
kfree(pdata);
return NULL;
}
void _stp_vfree_percpu(const void *objp)
{
int i;
struct _stp_percpu_data *p = (struct _stp_percpu_data *) (~(unsigned long) objp);
for (i = 0; i < NR_CPUS; i++) {
if (!cpu_possible(i))
continue;
vfree(p->ptrs[i]);
}
kfree(p);
}
#else
static inline void *__stp_valloc_percpu(size_t size, size_t align)
{
void *ret = kmalloc(size, GFP_KERNEL);
if (ret)
memset(ret, 0, size);
return ret;
}
void _stp_vfree_percpu(const void *ptr)
{
kfree(ptr);
}
#endif
#define _stp_valloc_percpu(type) \
((type *)(__stp_valloc_percpu(sizeof(type), __alignof__(type))))
#define _stp_percpu_dptr(ptr) (((struct _stp_percpu_data *)~(unsigned long)(ptr))->data)
/** Frees memory allocated by _stp_alloc or _stp_calloc.
* @param ptr pointer to memory to free
* @note Not currently used by the runtime. Deprecate?
*/
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_ */
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