alloc-r0drv-linux.c@ 85546

Last change on this file since 85546 was 85505, checked in by vboxsync, 4 years ago
IPRT/alloc-r0drv-linux.c,SUPDrv-linux.c: RTMEMALLOC_EXEC_HEAP for 5.8+ (more on this later as it doesn't really work). bugref:9801
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1	/* $Id: alloc-r0drv-linux.c 85505 2020-07-29 10:03:29Z vboxsync $ */
2	/** @file
3	* IPRT - Memory Allocation, Ring-0 Driver, Linux.
4	*/
5
6	/*
7	* Copyright (C) 2006-2020 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/errcore.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) && LINUX_VERSION_CODE < KERNEL_VERSION(5, 8, 0)
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/errcore.h>
63	#endif
64
65	#include "internal/initterm.h"
66
67
68	/*********************************************************************************************************************************
69	* Structures and Typedefs *
70	*********************************************************************************************************************************/
71	#ifdef RTMEMALLOC_EXEC_VM_AREA
72	/**
73	* Extended header used for headers marked with RTMEMHDR_FLAG_EXEC_VM_AREA.
74	*
75	* This is used with allocating executable memory, for things like generated
76	* code and loaded modules.
77	*/
78	typedef struct RTMEMLNXHDREX
79	{
80	/** The VM area for this allocation. */
81	struct vm_struct *pVmArea;
82	void *pvDummy;
83	/** The header we present to the generic API. */
84	RTMEMHDR Hdr;
85	} RTMEMLNXHDREX;
86	AssertCompileSize(RTMEMLNXHDREX, 32);
87	/** Pointer to an extended memory header. */
88	typedef RTMEMLNXHDREX *PRTMEMLNXHDREX;
89	#endif
90
91
92	/*********************************************************************************************************************************
93	* Global Variables *
94	*********************************************************************************************************************************/
95	#ifdef RTMEMALLOC_EXEC_HEAP
96	/** The heap. */
97	static RTHEAPSIMPLE g_HeapExec = NIL_RTHEAPSIMPLE;
98	/** Spinlock protecting the heap. */
99	static RTSPINLOCK g_HeapExecSpinlock = NIL_RTSPINLOCK;
100	#endif
101
102
103	/**
104	* API for cleaning up the heap spinlock on IPRT termination.
105	* This is as RTMemExecDonate specific to AMD64 Linux/GNU.
106	*/
107	DECLHIDDEN(void) rtR0MemExecCleanup(void)
108	{
109	#ifdef RTMEMALLOC_EXEC_HEAP
110	RTSpinlockDestroy(g_HeapExecSpinlock);
111	g_HeapExecSpinlock = NIL_RTSPINLOCK;
112	#endif
113	}
114
115
116	/**
117	* Donate read+write+execute memory to the exec heap.
118	*
119	* This API is specific to AMD64 and Linux/GNU. A kernel module that desires to
120	* use RTMemExecAlloc on AMD64 Linux/GNU will have to donate some statically
121	* allocated memory in the module if it wishes for GCC generated code to work.
122	* GCC can only generate modules that work in the address range ~2GB to ~0
123	* currently.
124	*
125	* The API only accept one single donation.
126	*
127	* @returns IPRT status code.
128	* @retval VERR_NOT_SUPPORTED if the code isn't enabled.
129	* @param pvMemory Pointer to the memory block.
130	* @param cb The size of the memory block.
131	*/
132	RTR0DECL(int) RTR0MemExecDonate(void *pvMemory, size_t cb)
133	{
134	#ifdef RTMEMALLOC_EXEC_HEAP
135	int rc;
136	AssertReturn(g_HeapExec == NIL_RTHEAPSIMPLE, VERR_WRONG_ORDER);
137
138	rc = RTSpinlockCreate(&g_HeapExecSpinlock, RTSPINLOCK_FLAGS_INTERRUPT_SAFE, "RTR0MemExecDonate");
139	if (RT_SUCCESS(rc))
140	{
141	rc = RTHeapSimpleInit(&g_HeapExec, pvMemory, cb);
142	if (RT_FAILURE(rc))
143	rtR0MemExecCleanup();
144	}
145	return rc;
146	#else
147	RT_NOREF_PV(pvMemory); RT_NOREF_PV(cb);
148	return VERR_NOT_SUPPORTED;
149	#endif
150	}
151	RT_EXPORT_SYMBOL(RTR0MemExecDonate);
152
153
154
155	#ifdef RTMEMALLOC_EXEC_VM_AREA
156	/**
157	* Allocate executable kernel memory in the module range.
158	*
159	* @returns Pointer to a allocation header success. NULL on failure.
160	*
161	* @param cb The size the user requested.
162	*/
163	static PRTMEMHDR rtR0MemAllocExecVmArea(size_t cb)
164	{
165	size_t const cbAlloc = RT_ALIGN_Z(sizeof(RTMEMLNXHDREX) + cb, PAGE_SIZE);
166	size_t const cPages = cbAlloc >> PAGE_SHIFT;
167	struct page **papPages;
168	struct vm_struct *pVmArea;
169	size_t iPage;
170
171	pVmArea = __get_vm_area(cbAlloc, VM_ALLOC, MODULES_VADDR, MODULES_END);
172	if (!pVmArea)
173	return NULL;
174	pVmArea->nr_pages = 0; /* paranoia? */
175	pVmArea->pages = NULL; /* paranoia? */
176
177	papPages = (struct page *)kmalloc(cPages sizeof(papPages[0]), GFP_KERNEL \| __GFP_NOWARN);
178	if (!papPages)
179	{
180	vunmap(pVmArea->addr);
181	return NULL;
182	}
183
184	for (iPage = 0; iPage < cPages; iPage++)
185	{
186	papPages[iPage] = alloc_page(GFP_KERNEL \| __GFP_HIGHMEM \| __GFP_NOWARN);
187	if (!papPages[iPage])
188	break;
189	}
190	if (iPage == cPages)
191	{
192	/*
193	* Map the pages.
194	*
195	* Not entirely sure we really need to set nr_pages and pages here, but
196	* they provide a very convenient place for storing something we need
197	* in the free function, if nothing else...
198	*/
199	# if LINUX_VERSION_CODE < KERNEL_VERSION(3, 17, 0)
200	struct page **papPagesIterator = papPages;
201	# endif
202	pVmArea->nr_pages = cPages;
203	pVmArea->pages = papPages;
204	if (!map_vm_area(pVmArea, PAGE_KERNEL_EXEC,
205	# if LINUX_VERSION_CODE < KERNEL_VERSION(3, 17, 0)
206	&papPagesIterator
207	# else
208	papPages
209	# endif
210	))
211	{
212	PRTMEMLNXHDREX pHdrEx = (PRTMEMLNXHDREX)pVmArea->addr;
213	pHdrEx->pVmArea = pVmArea;
214	pHdrEx->pvDummy = NULL;
215	return &pHdrEx->Hdr;
216	}
217	/* bail out */
218	# if LINUX_VERSION_CODE < KERNEL_VERSION(3, 17, 0)
219	pVmArea->nr_pages = papPagesIterator - papPages;
220	# endif
221	}
222
223	vunmap(pVmArea->addr);
224
225	while (iPage-- > 0)
226	__free_page(papPages[iPage]);
227	kfree(papPages);
228
229	return NULL;
230	}
231	#endif /* RTMEMALLOC_EXEC_VM_AREA */
232
233
234	/**
235	* OS specific allocation function.
236	*/
237	DECLHIDDEN(int) rtR0MemAllocEx(size_t cb, uint32_t fFlags, PRTMEMHDR *ppHdr)
238	{
239	PRTMEMHDR pHdr;
240	IPRT_LINUX_SAVE_EFL_AC();
241
242	/*
243	* Allocate.
244	*/
245	if (fFlags & RTMEMHDR_FLAG_EXEC)
246	{
247	if (fFlags & RTMEMHDR_FLAG_ANY_CTX)
248	return VERR_NOT_SUPPORTED;
249
250	#if defined(RT_ARCH_AMD64)
251	# ifdef RTMEMALLOC_EXEC_HEAP
252	if (g_HeapExec != NIL_RTHEAPSIMPLE)
253	{
254	RTSpinlockAcquire(g_HeapExecSpinlock);
255	pHdr = (PRTMEMHDR)RTHeapSimpleAlloc(g_HeapExec, cb + sizeof(*pHdr), 0);
256	RTSpinlockRelease(g_HeapExecSpinlock);
257	fFlags \|= RTMEMHDR_FLAG_EXEC_HEAP;
258	}
259	else
260	pHdr = NULL;
261
262	# elif defined(RTMEMALLOC_EXEC_VM_AREA)
263	pHdr = rtR0MemAllocExecVmArea(cb);
264	fFlags \|= RTMEMHDR_FLAG_EXEC_VM_AREA;
265
266	# else /* !RTMEMALLOC_EXEC_HEAP */
267	# error "you don not want to go here..."
268	pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL \| __GFP_HIGHMEM \| __GFP_NOWARN, MY_PAGE_KERNEL_EXEC);
269	# endif /* !RTMEMALLOC_EXEC_HEAP */
270
271	#elif defined(PAGE_KERNEL_EXEC) && defined(CONFIG_X86_PAE)
272	pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL \| __GFP_HIGHMEM \| __GFP_NOWARN, MY_PAGE_KERNEL_EXEC);
273	#else
274	pHdr = (PRTMEMHDR)vmalloc(cb + sizeof(*pHdr));
275	#endif
276	}
277	else
278	{
279	if (
280	#if 1 /* vmalloc has serious performance issues, avoid it. */
281	cb <= PAGE_SIZE16 - sizeof(pHdr)
282	#else
283	cb <= PAGE_SIZE
284	#endif
285	\|\| (fFlags & RTMEMHDR_FLAG_ANY_CTX)
286	)
287	{
288	fFlags \|= RTMEMHDR_FLAG_KMALLOC;
289	pHdr = kmalloc(cb + sizeof(*pHdr),
290	(fFlags & RTMEMHDR_FLAG_ANY_CTX_ALLOC) ? (GFP_ATOMIC \| __GFP_NOWARN)
291	: (GFP_KERNEL \| __GFP_NOWARN));
292	if (RT_UNLIKELY( !pHdr
293	&& cb > PAGE_SIZE
294	&& !(fFlags & RTMEMHDR_FLAG_ANY_CTX) ))
295	{
296	fFlags &= ~RTMEMHDR_FLAG_KMALLOC;
297	pHdr = vmalloc(cb + sizeof(*pHdr));
298	}
299	}
300	else
301	pHdr = vmalloc(cb + sizeof(*pHdr));
302	}
303	if (RT_UNLIKELY(!pHdr))
304	{
305	IPRT_LINUX_RESTORE_EFL_AC();
306	return VERR_NO_MEMORY;
307	}
308
309	/*
310	* Initialize.
311	*/
312	pHdr->u32Magic = RTMEMHDR_MAGIC;
313	pHdr->fFlags = fFlags;
314	pHdr->cb = cb;
315	pHdr->cbReq = cb;
316
317	*ppHdr = pHdr;
318	IPRT_LINUX_RESTORE_EFL_AC();
319	return VINF_SUCCESS;
320	}
321
322
323	/**
324	* OS specific free function.
325	*/
326	DECLHIDDEN(void) rtR0MemFree(PRTMEMHDR pHdr)
327	{
328	IPRT_LINUX_SAVE_EFL_AC();
329
330	pHdr->u32Magic += 1;
331	if (pHdr->fFlags & RTMEMHDR_FLAG_KMALLOC)
332	kfree(pHdr);
333	#ifdef RTMEMALLOC_EXEC_HEAP
334	else if (pHdr->fFlags & RTMEMHDR_FLAG_EXEC_HEAP)
335	{
336	RTSpinlockAcquire(g_HeapExecSpinlock);
337	RTHeapSimpleFree(g_HeapExec, pHdr);
338	RTSpinlockRelease(g_HeapExecSpinlock);
339	}
340	#endif
341	#ifdef RTMEMALLOC_EXEC_VM_AREA
342	else if (pHdr->fFlags & RTMEMHDR_FLAG_EXEC_VM_AREA)
343	{
344	PRTMEMLNXHDREX pHdrEx = RT_FROM_MEMBER(pHdr, RTMEMLNXHDREX, Hdr);
345	size_t iPage = pHdrEx->pVmArea->nr_pages;
346	struct page **papPages = pHdrEx->pVmArea->pages;
347	void *pvMapping = pHdrEx->pVmArea->addr;
348
349	vunmap(pvMapping);
350
351	while (iPage-- > 0)
352	__free_page(papPages[iPage]);
353	kfree(papPages);
354	}
355	#endif
356	else
357	vfree(pHdr);
358
359	IPRT_LINUX_RESTORE_EFL_AC();
360	}
361
362
363
364	/**
365	* Compute order. Some functions allocate 2^order pages.
366	*
367	* @returns order.
368	* @param cPages Number of pages.
369	*/
370	static int CalcPowerOf2Order(unsigned long cPages)
371	{
372	int iOrder;
373	unsigned long cTmp;
374
375	for (iOrder = 0, cTmp = cPages; cTmp >>= 1; ++iOrder)
376	;
377	if (cPages & ~(1 << iOrder))
378	++iOrder;
379
380	return iOrder;
381	}
382
383
384	/**
385	* Allocates physical contiguous memory (below 4GB).
386	* The allocation is page aligned and the content is undefined.
387	*
388	* @returns Pointer to the memory block. This is page aligned.
389	* @param pPhys Where to store the physical address.
390	* @param cb The allocation size in bytes. This is always
391	* rounded up to PAGE_SIZE.
392	*/
393	RTR0DECL(void *) RTMemContAlloc(PRTCCPHYS pPhys, size_t cb)
394	{
395	int cOrder;
396	unsigned cPages;
397	struct page *paPages;
398	void *pvRet;
399	IPRT_LINUX_SAVE_EFL_AC();
400
401	/*
402	* validate input.
403	*/
404	Assert(VALID_PTR(pPhys));
405	Assert(cb > 0);
406
407	/*
408	* Allocate page pointer array.
409	*/
410	cb = RT_ALIGN_Z(cb, PAGE_SIZE);
411	cPages = cb >> PAGE_SHIFT;
412	cOrder = CalcPowerOf2Order(cPages);
413	#if (defined(RT_ARCH_AMD64) \|\| defined(CONFIG_X86_PAE)) && defined(GFP_DMA32)
414	/* ZONE_DMA32: 0-4GB */
415	paPages = alloc_pages(GFP_DMA32 \| __GFP_NOWARN, cOrder);
416	if (!paPages)
417	#endif
418	#ifdef RT_ARCH_AMD64
419	/* ZONE_DMA; 0-16MB */
420	paPages = alloc_pages(GFP_DMA \| __GFP_NOWARN, cOrder);
421	#else
422	/* ZONE_NORMAL: 0-896MB */
423	paPages = alloc_pages(GFP_USER \| __GFP_NOWARN, cOrder);
424	#endif
425	if (paPages)
426	{
427	/*
428	* Reserve the pages and mark them executable.
429	*/
430	unsigned iPage;
431	for (iPage = 0; iPage < cPages; iPage++)
432	{
433	Assert(!PageHighMem(&paPages[iPage]));
434	if (iPage + 1 < cPages)
435	{
436	AssertMsg( (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage])) + PAGE_SIZE
437	== (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage + 1]))
438	&& page_to_phys(&paPages[iPage]) + PAGE_SIZE
439	== page_to_phys(&paPages[iPage + 1]),
440	("iPage=%i cPages=%u [0]=%#llx,%p [1]=%#llx,%p\n", iPage, cPages,
441	(long long)page_to_phys(&paPages[iPage]), phys_to_virt(page_to_phys(&paPages[iPage])),
442	(long long)page_to_phys(&paPages[iPage + 1]), phys_to_virt(page_to_phys(&paPages[iPage + 1])) ));
443	}
444
445	SetPageReserved(&paPages[iPage]);
446	}
447	*pPhys = page_to_phys(paPages);
448	pvRet = phys_to_virt(page_to_phys(paPages));
449	}
450	else
451	pvRet = NULL;
452
453	IPRT_LINUX_RESTORE_EFL_AC();
454	return pvRet;
455	}
456	RT_EXPORT_SYMBOL(RTMemContAlloc);
457
458
459	/**
460	* Frees memory allocated using RTMemContAlloc().
461	*
462	* @param pv Pointer to return from RTMemContAlloc().
463	* @param cb The cb parameter passed to RTMemContAlloc().
464	*/
465	RTR0DECL(void) RTMemContFree(void *pv, size_t cb)
466	{
467	if (pv)
468	{
469	int cOrder;
470	unsigned cPages;
471	unsigned iPage;
472	struct page *paPages;
473	IPRT_LINUX_SAVE_EFL_AC();
474
475	/* validate */
476	AssertMsg(!((uintptr_t)pv & PAGE_OFFSET_MASK), ("pv=%p\n", pv));
477	Assert(cb > 0);
478
479	/* calc order and get pages */
480	cb = RT_ALIGN_Z(cb, PAGE_SIZE);
481	cPages = cb >> PAGE_SHIFT;
482	cOrder = CalcPowerOf2Order(cPages);
483	paPages = virt_to_page(pv);
484
485	/*
486	* Restore page attributes freeing the pages.
487	*/
488	for (iPage = 0; iPage < cPages; iPage++)
489	{
490	ClearPageReserved(&paPages[iPage]);
491	}
492	__free_pages(paPages, cOrder);
493	IPRT_LINUX_RESTORE_EFL_AC();
494	}
495	}
496	RT_EXPORT_SYMBOL(RTMemContFree);
497

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source: vbox/trunk/src/VBox/Runtime/r0drv/linux/alloc-r0drv-linux.c@ 85546

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