alloc-r0drv-linux.c@ 32707

Last change on this file since 32707 was 32707, checked in by vboxsync, 15 years ago
IPRT: Added RTMemAllocEx[Tag] and RTMemFreeEx, only implemented in ring-0 only.
Property svn:eol-style set to `native` Property svn:keywords set to `Id`
File size: 9.8 KB

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1	/* $Id: alloc-r0drv-linux.c 32707 2010-09-23 10:15:08Z vboxsync $ */
2	/** @file
3	* IPRT - Memory Allocation, Ring-0 Driver, Linux.
4	*/
5
6	/*
7	* Copyright (C) 2006-2007 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*
17	* The contents of this file may alternatively be used under the terms
18	* of the Common Development and Distribution License Version 1.0
19	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20	* VirtualBox OSE distribution, in which case the provisions of the
21	* CDDL are applicable instead of those of the GPL.
22	*
23	* You may elect to license modified versions of this file under the
24	* terms and conditions of either the GPL or the CDDL or both.
25	*/
26
27
28	/*******************************************************************************
29	* Header Files *
30	*******************************************************************************/
31	#include "the-linux-kernel.h"
32	#include "internal/iprt.h"
33
34	#include <iprt/mem.h>
35	#include <iprt/assert.h>
36	#include "r0drv/alloc-r0drv.h"
37
38	#if defined(RT_ARCH_AMD64) \|\| defined(DOXYGEN_RUNNING)
39	/**
40	* We need memory in the module range (~2GB to ~0) this can only be obtained
41	* thru APIs that are not exported (see module_alloc()).
42	*
43	* So, we'll have to create a quick and dirty heap here using BSS memory.
44	* Very annoying and it's going to restrict us!
45	*/
46	# define RTMEMALLOC_EXEC_HEAP
47	#endif
48	#ifdef RTMEMALLOC_EXEC_HEAP
49	# include <iprt/heap.h>
50	# include <iprt/spinlock.h>
51	# include <iprt/err.h>
52	#endif
53
54
55	/*******************************************************************************
56	* Global Variables *
57	*******************************************************************************/
58	#ifdef RTMEMALLOC_EXEC_HEAP
59	/** The heap. */
60	static RTHEAPSIMPLE g_HeapExec = NIL_RTHEAPSIMPLE;
61	/** Spinlock protecting the heap. */
62	static RTSPINLOCK g_HeapExecSpinlock = NIL_RTSPINLOCK;
63
64
65	/**
66	* API for cleaning up the heap spinlock on IPRT termination.
67	* This is as RTMemExecDonate specific to AMD64 Linux/GNU.
68	*/
69	void rtR0MemExecCleanup(void)
70	{
71	RTSpinlockDestroy(g_HeapExecSpinlock);
72	g_HeapExecSpinlock = NIL_RTSPINLOCK;
73	}
74
75
76	/**
77	* Donate read+write+execute memory to the exec heap.
78	*
79	* This API is specific to AMD64 and Linux/GNU. A kernel module that desires to
80	* use RTMemExecAlloc on AMD64 Linux/GNU will have to donate some statically
81	* allocated memory in the module if it wishes for GCC generated code to work.
82	* GCC can only generate modules that work in the address range ~2GB to ~0
83	* currently.
84	*
85	* The API only accept one single donation.
86	*
87	* @returns IPRT status code.
88	* @param pvMemory Pointer to the memory block.
89	* @param cb The size of the memory block.
90	*/
91	RTR0DECL(int) RTR0MemExecDonate(void *pvMemory, size_t cb)
92	{
93	int rc;
94	AssertReturn(g_HeapExec == NIL_RTHEAPSIMPLE, VERR_WRONG_ORDER);
95
96	rc = RTSpinlockCreate(&g_HeapExecSpinlock);
97	if (RT_SUCCESS(rc))
98	{
99	rc = RTHeapSimpleInit(&g_HeapExec, pvMemory, cb);
100	if (RT_FAILURE(rc))
101	rtR0MemExecCleanup();
102	}
103	return rc;
104	}
105	RT_EXPORT_SYMBOL(RTR0MemExecDonate);
106	#endif /* RTMEMALLOC_EXEC_HEAP */
107
108
109
110	/**
111	* OS specific allocation function.
112	*/
113	int rtR0MemAllocEx(size_t cb, uint32_t fFlags, PRTMEMHDR *ppHdr)
114	{
115	PRTMEMHDR pHdr;
116
117	/*
118	* Allocate.
119	*/
120	if (fFlags & RTMEMHDR_FLAG_EXEC)
121	{
122	if (fFlags & RTMEMHDR_FLAG_ANY_CTX)
123	return VERR_NOT_SUPPORTED;
124
125	#if defined(RT_ARCH_AMD64)
126	# ifdef RTMEMALLOC_EXEC_HEAP
127	if (g_HeapExec != NIL_RTHEAPSIMPLE)
128	{
129	RTSPINLOCKTMP SpinlockTmp = RTSPINLOCKTMP_INITIALIZER;
130	RTSpinlockAcquireNoInts(g_HeapExecSpinlock, &SpinlockTmp);
131	pHdr = (PRTMEMHDR)RTHeapSimpleAlloc(g_HeapExec, cb + sizeof(*pHdr), 0);
132	RTSpinlockReleaseNoInts(g_HeapExecSpinlock, &SpinlockTmp);
133	fFlags \|= RTMEMHDR_FLAG_EXEC_HEAP;
134	}
135	else
136	pHdr = NULL;
137	# else /* !RTMEMALLOC_EXEC_HEAP */
138	pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL \| __GFP_HIGHMEM, MY_PAGE_KERNEL_EXEC);
139	# endif /* !RTMEMALLOC_EXEC_HEAP */
140
141	#elif defined(PAGE_KERNEL_EXEC) && defined(CONFIG_X86_PAE)
142	pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL \| __GFP_HIGHMEM, MY_PAGE_KERNEL_EXEC);
143	#else
144	pHdr = (PRTMEMHDR)vmalloc(cb + sizeof(*pHdr));
145	#endif
146	}
147	else
148	{
149	if (cb <= PAGE_SIZE \|\| (fFlags & RTMEMHDR_FLAG_ANY_CTX))
150	{
151	fFlags \|= RTMEMHDR_FLAG_KMALLOC;
152	pHdr = kmalloc(cb + sizeof(*pHdr),
153	(fFlags & RTMEMHDR_FLAG_ANY_CTX_ALLOC) ? GFP_ATOMIC : GFP_KERNEL);
154	}
155	else
156	pHdr = vmalloc(cb + sizeof(*pHdr));
157	}
158	if (RT_UNLIKELY(!pHdr))
159	return VERR_NO_MEMORY;
160
161	/*
162	* Initialize.
163	*/
164	pHdr->u32Magic = RTMEMHDR_MAGIC;
165	pHdr->fFlags = fFlags;
166	pHdr->cb = cb;
167	pHdr->cbReq = cb;
168
169	*ppHdr = pHdr;
170	return VINF_SUCCESS;
171	}
172
173
174	/**
175	* OS specific free function.
176	*/
177	void rtR0MemFree(PRTMEMHDR pHdr)
178	{
179	pHdr->u32Magic += 1;
180	if (pHdr->fFlags & RTMEMHDR_FLAG_KMALLOC)
181	kfree(pHdr);
182	#ifdef RTMEMALLOC_EXEC_HEAP
183	else if (pHdr->fFlags & RTMEMHDR_FLAG_EXEC_HEAP)
184	{
185	RTSPINLOCKTMP SpinlockTmp = RTSPINLOCKTMP_INITIALIZER;
186	RTSpinlockAcquireNoInts(g_HeapExecSpinlock, &SpinlockTmp);
187	RTHeapSimpleFree(g_HeapExec, pHdr);
188	RTSpinlockReleaseNoInts(g_HeapExecSpinlock, &SpinlockTmp);
189	}
190	#endif
191	else
192	vfree(pHdr);
193	}
194
195
196	/**
197	* Compute order. Some functions allocate 2^order pages.
198	*
199	* @returns order.
200	* @param cPages Number of pages.
201	*/
202	static int CalcPowerOf2Order(unsigned long cPages)
203	{
204	int iOrder;
205	unsigned long cTmp;
206
207	for (iOrder = 0, cTmp = cPages; cTmp >>= 1; ++iOrder)
208	;
209	if (cPages & ~(1 << iOrder))
210	++iOrder;
211
212	return iOrder;
213	}
214
215
216	/**
217	* Allocates physical contiguous memory (below 4GB).
218	* The allocation is page aligned and the content is undefined.
219	*
220	* @returns Pointer to the memory block. This is page aligned.
221	* @param pPhys Where to store the physical address.
222	* @param cb The allocation size in bytes. This is always
223	* rounded up to PAGE_SIZE.
224	*/
225	RTR0DECL(void *) RTMemContAlloc(PRTCCPHYS pPhys, size_t cb)
226	{
227	int cOrder;
228	unsigned cPages;
229	struct page *paPages;
230
231	/*
232	* validate input.
233	*/
234	Assert(VALID_PTR(pPhys));
235	Assert(cb > 0);
236
237	/*
238	* Allocate page pointer array.
239	*/
240	cb = RT_ALIGN_Z(cb, PAGE_SIZE);
241	cPages = cb >> PAGE_SHIFT;
242	cOrder = CalcPowerOf2Order(cPages);
243	#if (defined(RT_ARCH_AMD64) \|\| defined(CONFIG_X86_PAE)) && defined(GFP_DMA32)
244	/* ZONE_DMA32: 0-4GB */
245	paPages = alloc_pages(GFP_DMA32, cOrder);
246	if (!paPages)
247	#endif
248	#ifdef RT_ARCH_AMD64
249	/* ZONE_DMA; 0-16MB */
250	paPages = alloc_pages(GFP_DMA, cOrder);
251	#else
252	/* ZONE_NORMAL: 0-896MB */
253	paPages = alloc_pages(GFP_USER, cOrder);
254	#endif
255	if (paPages)
256	{
257	/*
258	* Reserve the pages and mark them executable.
259	*/
260	unsigned iPage;
261	for (iPage = 0; iPage < cPages; iPage++)
262	{
263	Assert(!PageHighMem(&paPages[iPage]));
264	if (iPage + 1 < cPages)
265	{
266	AssertMsg( (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage])) + PAGE_SIZE
267	== (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage + 1]))
268	&& page_to_phys(&paPages[iPage]) + PAGE_SIZE
269	== page_to_phys(&paPages[iPage + 1]),
270	("iPage=%i cPages=%u [0]=%#llx,%p [1]=%#llx,%p\n", iPage, cPages,
271	(long long)page_to_phys(&paPages[iPage]), phys_to_virt(page_to_phys(&paPages[iPage])),
272	(long long)page_to_phys(&paPages[iPage + 1]), phys_to_virt(page_to_phys(&paPages[iPage + 1])) ));
273	}
274
275	SetPageReserved(&paPages[iPage]);
276	#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */
277	MY_SET_PAGES_EXEC(&paPages[iPage], 1);
278	#endif
279	}
280	*pPhys = page_to_phys(paPages);
281	return phys_to_virt(page_to_phys(paPages));
282	}
283
284	return NULL;
285	}
286	RT_EXPORT_SYMBOL(RTMemContAlloc);
287
288
289	/**
290	* Frees memory allocated ysing RTMemContAlloc().
291	*
292	* @param pv Pointer to return from RTMemContAlloc().
293	* @param cb The cb parameter passed to RTMemContAlloc().
294	*/
295	RTR0DECL(void) RTMemContFree(void *pv, size_t cb)
296	{
297	if (pv)
298	{
299	int cOrder;
300	unsigned cPages;
301	unsigned iPage;
302	struct page *paPages;
303
304	/* validate */
305	AssertMsg(!((uintptr_t)pv & PAGE_OFFSET_MASK), ("pv=%p\n", pv));
306	Assert(cb > 0);
307
308	/* calc order and get pages */
309	cb = RT_ALIGN_Z(cb, PAGE_SIZE);
310	cPages = cb >> PAGE_SHIFT;
311	cOrder = CalcPowerOf2Order(cPages);
312	paPages = virt_to_page(pv);
313
314	/*
315	* Restore page attributes freeing the pages.
316	*/
317	for (iPage = 0; iPage < cPages; iPage++)
318	{
319	ClearPageReserved(&paPages[iPage]);
320	#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */
321	MY_SET_PAGES_NOEXEC(&paPages[iPage], 1);
322	#endif
323	}
324	__free_pages(paPages, cOrder);
325	}
326	}
327	RT_EXPORT_SYMBOL(RTMemContFree);
328

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source: vbox/trunk/src/VBox/Runtime/r0drv/linux/alloc-r0drv-linux.c@ 32707

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