alloc-r0drv-linux.c@ 50008

Last change on this file since 50008 was 50008, checked in by vboxsync, 11 years ago
supdrv,iprt: Added VBOX_WITH_TEXT_MODMEM_HACK for getting VMMR0.r0 address in the linux kernel stack crawl.
Property svn:eol-style set to `native` Property svn:keywords set to `Id Revision`
File size: 14.2 KB

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1	/* $Id: alloc-r0drv-linux.c 50008 2013-12-27 14:20:34Z vboxsync $ */
2	/** @file
3	* IPRT - Memory Allocation, Ring-0 Driver, Linux.
4	*/
5
6	/*
7	* Copyright (C) 2006-2012 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	#include <iprt/mem.h>
34
35	#include <iprt/assert.h>
36	#include <iprt/err.h>
37	#include "r0drv/alloc-r0drv.h"
38
39
40	#if (defined(RT_ARCH_AMD64) \|\| defined(DOXYGEN_RUNNING)) && !defined(RTMEMALLOC_EXEC_HEAP)
41	# if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 23)
42	/**
43	* Starting with 2.6.23 we can use __get_vm_area and map_vm_area to allocate
44	* memory in the moduel range. This is preferrable to the exec heap below.
45	*/
46	# define RTMEMALLOC_EXEC_VM_AREA
47	# else
48	/**
49	* We need memory in the module range (~2GB to ~0) this can only be obtained
50	* thru APIs that are not exported (see module_alloc()).
51	*
52	* So, we'll have to create a quick and dirty heap here using BSS memory.
53	* Very annoying and it's going to restrict us!
54	*/
55	# define RTMEMALLOC_EXEC_HEAP
56	# endif
57	#endif
58
59	#ifdef RTMEMALLOC_EXEC_HEAP
60	# include <iprt/heap.h>
61	# include <iprt/spinlock.h>
62	# include <iprt/err.h>
63	#endif
64
65
66	/*******************************************************************************
67	* Structures and Typedefs *
68	*******************************************************************************/
69	#ifdef RTMEMALLOC_EXEC_VM_AREA
70	/**
71	* Extended header used for headers marked with RTMEMHDR_FLAG_EXEC_VM_AREA.
72	*
73	* This is used with allocating executable memory, for things like generated
74	* code and loaded modules.
75	*/
76	typedef struct RTMEMLNXHDREX
77	{
78	/** The VM area for this allocation. */
79	struct vm_struct *pVmArea;
80	void *pvDummy;
81	/** The header we present to the generic API. */
82	RTMEMHDR Hdr;
83	} RTMEMLNXHDREX;
84	AssertCompileSize(RTMEMLNXHDREX, 32);
85	/** Pointer to an extended memory header. */
86	typedef RTMEMLNXHDREX *PRTMEMLNXHDREX;
87	#endif
88
89
90	/*******************************************************************************
91	* Global Variables *
92	*******************************************************************************/
93	#ifdef RTMEMALLOC_EXEC_HEAP
94	/** The heap. */
95	static RTHEAPSIMPLE g_HeapExec = NIL_RTHEAPSIMPLE;
96	/** Spinlock protecting the heap. */
97	static RTSPINLOCK g_HeapExecSpinlock = NIL_RTSPINLOCK;
98	#endif
99
100
101	/**
102	* API for cleaning up the heap spinlock on IPRT termination.
103	* This is as RTMemExecDonate specific to AMD64 Linux/GNU.
104	*/
105	DECLHIDDEN(void) rtR0MemExecCleanup(void)
106	{
107	#ifdef RTMEMALLOC_EXEC_HEAP
108	RTSpinlockDestroy(g_HeapExecSpinlock);
109	g_HeapExecSpinlock = NIL_RTSPINLOCK;
110	#endif
111	}
112
113
114	/**
115	* Donate read+write+execute memory to the exec heap.
116	*
117	* This API is specific to AMD64 and Linux/GNU. A kernel module that desires to
118	* use RTMemExecAlloc on AMD64 Linux/GNU will have to donate some statically
119	* allocated memory in the module if it wishes for GCC generated code to work.
120	* GCC can only generate modules that work in the address range ~2GB to ~0
121	* currently.
122	*
123	* The API only accept one single donation.
124	*
125	* @returns IPRT status code.
126	* @retval VERR_NOT_SUPPORTED if the code isn't enabled.
127	* @param pvMemory Pointer to the memory block.
128	* @param cb The size of the memory block.
129	*/
130	RTR0DECL(int) RTR0MemExecDonate(void *pvMemory, size_t cb)
131	{
132	#ifdef RTMEMALLOC_EXEC_HEAP
133	int rc;
134	AssertReturn(g_HeapExec == NIL_RTHEAPSIMPLE, VERR_WRONG_ORDER);
135
136	rc = RTSpinlockCreate(&g_HeapExecSpinlock, RTSPINLOCK_FLAGS_INTERRUPT_SAFE, "RTR0MemExecDonate");
137	if (RT_SUCCESS(rc))
138	{
139	rc = RTHeapSimpleInit(&g_HeapExec, pvMemory, cb);
140	if (RT_FAILURE(rc))
141	rtR0MemExecCleanup();
142	}
143	return rc;
144	#else
145	return VERR_NOT_SUPPORTED;
146	#endif
147	}
148	RT_EXPORT_SYMBOL(RTR0MemExecDonate);
149
150
151
152	#ifdef RTMEMALLOC_EXEC_VM_AREA
153	/**
154	* Allocate executable kernel memory in the module range.
155	*
156	* @returns Pointer to a allocation header success. NULL on failure.
157	*
158	* @param cb The size the user requested.
159	*/
160	static PRTMEMHDR rtR0MemAllocExecVmArea(size_t cb)
161	{
162	size_t const cbAlloc = RT_ALIGN_Z(sizeof(RTMEMLNXHDREX) + cb, PAGE_SIZE);
163	size_t const cPages = cbAlloc >> PAGE_SHIFT;
164	struct page **papPages;
165	struct vm_struct *pVmArea;
166	size_t iPage;
167
168	pVmArea = __get_vm_area(cbAlloc, VM_ALLOC, MODULES_VADDR, MODULES_END);
169	if (!pVmArea)
170	return NULL;
171	pVmArea->nr_pages = 0; /* paranoia? */
172	pVmArea->pages = NULL; /* paranoia? */
173
174	papPages = (struct page *)kmalloc(cPages sizeof(papPages[0]), GFP_KERNEL);
175	if (!papPages)
176	{
177	vunmap(pVmArea->addr);
178	return NULL;
179	}
180
181	for (iPage = 0; iPage < cPages; iPage++)
182	{
183	papPages[iPage] = alloc_page(GFP_KERNEL \| __GFP_HIGHMEM);
184	if (!papPages[iPage])
185	break;
186	}
187	if (iPage == cPages)
188	{
189	/*
190	* Map the pages. The API requires an iterator argument, which can be
191	* used, in case of failure, to figure out how much was actually
192	* mapped. Not sure how useful this really is, but whatever.
193	*
194	* Not entirely sure we really need to set nr_pages and pages here, but
195	* they provide a very convenient place for storing something we need
196	* in the free function, if nothing else...
197	*/
198	struct page **papPagesIterator = papPages;
199	pVmArea->nr_pages = cPages;
200	pVmArea->pages = papPages;
201	if (!map_vm_area(pVmArea, PAGE_KERNEL_EXEC, &papPagesIterator))
202	{
203	PRTMEMLNXHDREX pHdrEx = (PRTMEMLNXHDREX)pVmArea->addr;
204	pHdrEx->pVmArea = pVmArea;
205	pHdrEx->pvDummy = NULL;
206	return &pHdrEx->Hdr;
207	}
208
209	/* bail out */
210	pVmArea->nr_pages = papPagesIterator - papPages;
211	}
212
213	vunmap(pVmArea->addr);
214
215	while (iPage-- > 0)
216	__free_page(papPages[iPage]);
217	kfree(papPages);
218
219	return NULL;
220	}
221	#endif /* RTMEMALLOC_EXEC_VM_AREA */
222
223
224	/**
225	* OS specific allocation function.
226	*/
227	DECLHIDDEN(int) rtR0MemAllocEx(size_t cb, uint32_t fFlags, PRTMEMHDR *ppHdr)
228	{
229	PRTMEMHDR pHdr;
230
231	/*
232	* Allocate.
233	*/
234	if (fFlags & RTMEMHDR_FLAG_EXEC)
235	{
236	if (fFlags & RTMEMHDR_FLAG_ANY_CTX)
237	return VERR_NOT_SUPPORTED;
238
239	#if defined(RT_ARCH_AMD64)
240	# ifdef RTMEMALLOC_EXEC_HEAP
241	if (g_HeapExec != NIL_RTHEAPSIMPLE)
242	{
243	RTSpinlockAcquire(g_HeapExecSpinlock);
244	pHdr = (PRTMEMHDR)RTHeapSimpleAlloc(g_HeapExec, cb + sizeof(*pHdr), 0);
245	RTSpinlockRelease(g_HeapExecSpinlock);
246	fFlags \|= RTMEMHDR_FLAG_EXEC_HEAP;
247	}
248	else
249	pHdr = NULL;
250
251	# elif defined(RTMEMALLOC_EXEC_VM_AREA)
252	pHdr = rtR0MemAllocExecVmArea(cb);
253	fFlags \|= RTMEMHDR_FLAG_EXEC_VM_AREA;
254
255	# else /* !RTMEMALLOC_EXEC_HEAP */
256	# error "you don not want to go here..."
257	pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL \| __GFP_HIGHMEM, MY_PAGE_KERNEL_EXEC);
258	# endif /* !RTMEMALLOC_EXEC_HEAP */
259
260	#elif defined(PAGE_KERNEL_EXEC) && defined(CONFIG_X86_PAE)
261	pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL \| __GFP_HIGHMEM, MY_PAGE_KERNEL_EXEC);
262	#else
263	pHdr = (PRTMEMHDR)vmalloc(cb + sizeof(*pHdr));
264	#endif
265	}
266	else
267	{
268	if (
269	#if 1 /* vmalloc has serious performance issues, avoid it. */
270	cb <= PAGE_SIZE16 - sizeof(pHdr)
271	#else
272	cb <= PAGE_SIZE
273	#endif
274	\|\| (fFlags & RTMEMHDR_FLAG_ANY_CTX)
275	)
276	{
277	fFlags \|= RTMEMHDR_FLAG_KMALLOC;
278	pHdr = kmalloc(cb + sizeof(*pHdr),
279	(fFlags & RTMEMHDR_FLAG_ANY_CTX_ALLOC) ? GFP_ATOMIC : GFP_KERNEL);
280	if (RT_UNLIKELY( !pHdr
281	&& cb > PAGE_SIZE
282	&& !(fFlags & RTMEMHDR_FLAG_ANY_CTX) ))
283	{
284	fFlags &= ~RTMEMHDR_FLAG_KMALLOC;
285	pHdr = vmalloc(cb + sizeof(*pHdr));
286	}
287	}
288	else
289	pHdr = vmalloc(cb + sizeof(*pHdr));
290	}
291	if (RT_UNLIKELY(!pHdr))
292	return VERR_NO_MEMORY;
293
294	/*
295	* Initialize.
296	*/
297	pHdr->u32Magic = RTMEMHDR_MAGIC;
298	pHdr->fFlags = fFlags;
299	pHdr->cb = cb;
300	pHdr->cbReq = cb;
301
302	*ppHdr = pHdr;
303	return VINF_SUCCESS;
304	}
305
306
307	/**
308	* OS specific free function.
309	*/
310	DECLHIDDEN(void) rtR0MemFree(PRTMEMHDR pHdr)
311	{
312	pHdr->u32Magic += 1;
313	if (pHdr->fFlags & RTMEMHDR_FLAG_KMALLOC)
314	kfree(pHdr);
315	#ifdef RTMEMALLOC_EXEC_HEAP
316	else if (pHdr->fFlags & RTMEMHDR_FLAG_EXEC_HEAP)
317	{
318	RTSpinlockAcquire(g_HeapExecSpinlock);
319	RTHeapSimpleFree(g_HeapExec, pHdr);
320	RTSpinlockRelease(g_HeapExecSpinlock);
321	}
322	#endif
323	#ifdef RTMEMALLOC_EXEC_VM_AREA
324	else if (pHdr->fFlags & RTMEMHDR_FLAG_EXEC_VM_AREA)
325	{
326	PRTMEMLNXHDREX pHdrEx = RT_FROM_MEMBER(pHdr, RTMEMLNXHDREX, Hdr);
327	size_t iPage = pHdrEx->pVmArea->nr_pages;
328	struct page **papPages = pHdrEx->pVmArea->pages;
329	void *pvMapping = pHdrEx->pVmArea->addr;
330
331	vunmap(pvMapping);
332
333	while (iPage-- > 0)
334	__free_page(papPages[iPage]);
335	kfree(papPages);
336	}
337	#endif
338	else
339	vfree(pHdr);
340	}
341
342
343
344	/**
345	* Compute order. Some functions allocate 2^order pages.
346	*
347	* @returns order.
348	* @param cPages Number of pages.
349	*/
350	static int CalcPowerOf2Order(unsigned long cPages)
351	{
352	int iOrder;
353	unsigned long cTmp;
354
355	for (iOrder = 0, cTmp = cPages; cTmp >>= 1; ++iOrder)
356	;
357	if (cPages & ~(1 << iOrder))
358	++iOrder;
359
360	return iOrder;
361	}
362
363
364	/**
365	* Allocates physical contiguous memory (below 4GB).
366	* The allocation is page aligned and the content is undefined.
367	*
368	* @returns Pointer to the memory block. This is page aligned.
369	* @param pPhys Where to store the physical address.
370	* @param cb The allocation size in bytes. This is always
371	* rounded up to PAGE_SIZE.
372	*/
373	RTR0DECL(void *) RTMemContAlloc(PRTCCPHYS pPhys, size_t cb)
374	{
375	int cOrder;
376	unsigned cPages;
377	struct page *paPages;
378
379	/*
380	* validate input.
381	*/
382	Assert(VALID_PTR(pPhys));
383	Assert(cb > 0);
384
385	/*
386	* Allocate page pointer array.
387	*/
388	cb = RT_ALIGN_Z(cb, PAGE_SIZE);
389	cPages = cb >> PAGE_SHIFT;
390	cOrder = CalcPowerOf2Order(cPages);
391	#if (defined(RT_ARCH_AMD64) \|\| defined(CONFIG_X86_PAE)) && defined(GFP_DMA32)
392	/* ZONE_DMA32: 0-4GB */
393	paPages = alloc_pages(GFP_DMA32, cOrder);
394	if (!paPages)
395	#endif
396	#ifdef RT_ARCH_AMD64
397	/* ZONE_DMA; 0-16MB */
398	paPages = alloc_pages(GFP_DMA, cOrder);
399	#else
400	/* ZONE_NORMAL: 0-896MB */
401	paPages = alloc_pages(GFP_USER, cOrder);
402	#endif
403	if (paPages)
404	{
405	/*
406	* Reserve the pages and mark them executable.
407	*/
408	unsigned iPage;
409	for (iPage = 0; iPage < cPages; iPage++)
410	{
411	Assert(!PageHighMem(&paPages[iPage]));
412	if (iPage + 1 < cPages)
413	{
414	AssertMsg( (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage])) + PAGE_SIZE
415	== (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage + 1]))
416	&& page_to_phys(&paPages[iPage]) + PAGE_SIZE
417	== page_to_phys(&paPages[iPage + 1]),
418	("iPage=%i cPages=%u [0]=%#llx,%p [1]=%#llx,%p\n", iPage, cPages,
419	(long long)page_to_phys(&paPages[iPage]), phys_to_virt(page_to_phys(&paPages[iPage])),
420	(long long)page_to_phys(&paPages[iPage + 1]), phys_to_virt(page_to_phys(&paPages[iPage + 1])) ));
421	}
422
423	SetPageReserved(&paPages[iPage]);
424	#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */
425	MY_SET_PAGES_EXEC(&paPages[iPage], 1);
426	#endif
427	}
428	*pPhys = page_to_phys(paPages);
429	return phys_to_virt(page_to_phys(paPages));
430	}
431
432	return NULL;
433	}
434	RT_EXPORT_SYMBOL(RTMemContAlloc);
435
436
437	/**
438	* Frees memory allocated using RTMemContAlloc().
439	*
440	* @param pv Pointer to return from RTMemContAlloc().
441	* @param cb The cb parameter passed to RTMemContAlloc().
442	*/
443	RTR0DECL(void) RTMemContFree(void *pv, size_t cb)
444	{
445	if (pv)
446	{
447	int cOrder;
448	unsigned cPages;
449	unsigned iPage;
450	struct page *paPages;
451
452	/* validate */
453	AssertMsg(!((uintptr_t)pv & PAGE_OFFSET_MASK), ("pv=%p\n", pv));
454	Assert(cb > 0);
455
456	/* calc order and get pages */
457	cb = RT_ALIGN_Z(cb, PAGE_SIZE);
458	cPages = cb >> PAGE_SHIFT;
459	cOrder = CalcPowerOf2Order(cPages);
460	paPages = virt_to_page(pv);
461
462	/*
463	* Restore page attributes freeing the pages.
464	*/
465	for (iPage = 0; iPage < cPages; iPage++)
466	{
467	ClearPageReserved(&paPages[iPage]);
468	#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */
469	MY_SET_PAGES_NOEXEC(&paPages[iPage], 1);
470	#endif
471	}
472	__free_pages(paPages, cOrder);
473	}
474	}
475	RT_EXPORT_SYMBOL(RTMemContFree);
476

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source: vbox/trunk/src/VBox/Runtime/r0drv/linux/alloc-r0drv-linux.c@ 50008

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