VirtualBox

source: vbox/trunk/src/VBox/Runtime/r0drv/linux/alloc-r0drv-linux.c@ 55784

Last change on this file since 55784 was 52803, checked in by vboxsync, 10 years ago

added GFP_NOWARN to the remaining vmalloc/kmalloc operations

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File size: 14.5 KB
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1/* $Id: alloc-r0drv-linux.c 52803 2014-09-22 08:21:23Z 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 */
76typedef 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;
84AssertCompileSize(RTMEMLNXHDREX, 32);
85/** Pointer to an extended memory header. */
86typedef RTMEMLNXHDREX *PRTMEMLNXHDREX;
87#endif
88
89
90/*******************************************************************************
91* Global Variables *
92*******************************************************************************/
93#ifdef RTMEMALLOC_EXEC_HEAP
94/** The heap. */
95static RTHEAPSIMPLE g_HeapExec = NIL_RTHEAPSIMPLE;
96/** Spinlock protecting the heap. */
97static 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 */
105DECLHIDDEN(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 */
130RTR0DECL(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}
148RT_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 */
160static 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 | __GFP_NOWARN);
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 | __GFP_NOWARN);
184 if (!papPages[iPage])
185 break;
186 }
187 if (iPage == cPages)
188 {
189 /*
190 * Map the pages.
191 *
192 * Not entirely sure we really need to set nr_pages and pages here, but
193 * they provide a very convenient place for storing something we need
194 * in the free function, if nothing else...
195 */
196# if LINUX_VERSION_CODE < KERNEL_VERSION(3, 17, 0)
197 struct page **papPagesIterator = papPages;
198# endif
199 pVmArea->nr_pages = cPages;
200 pVmArea->pages = papPages;
201 if (!map_vm_area(pVmArea, PAGE_KERNEL_EXEC,
202# if LINUX_VERSION_CODE < KERNEL_VERSION(3, 17, 0)
203 &papPagesIterator
204# else
205 papPages
206# endif
207 ))
208 {
209 PRTMEMLNXHDREX pHdrEx = (PRTMEMLNXHDREX)pVmArea->addr;
210 pHdrEx->pVmArea = pVmArea;
211 pHdrEx->pvDummy = NULL;
212 return &pHdrEx->Hdr;
213 }
214 /* bail out */
215# if LINUX_VERSION_CODE < KERNEL_VERSION(3, 17, 0)
216 pVmArea->nr_pages = papPagesIterator - papPages;
217# endif
218 }
219
220 vunmap(pVmArea->addr);
221
222 while (iPage-- > 0)
223 __free_page(papPages[iPage]);
224 kfree(papPages);
225
226 return NULL;
227}
228#endif /* RTMEMALLOC_EXEC_VM_AREA */
229
230
231/**
232 * OS specific allocation function.
233 */
234DECLHIDDEN(int) rtR0MemAllocEx(size_t cb, uint32_t fFlags, PRTMEMHDR *ppHdr)
235{
236 PRTMEMHDR pHdr;
237
238 /*
239 * Allocate.
240 */
241 if (fFlags & RTMEMHDR_FLAG_EXEC)
242 {
243 if (fFlags & RTMEMHDR_FLAG_ANY_CTX)
244 return VERR_NOT_SUPPORTED;
245
246#if defined(RT_ARCH_AMD64)
247# ifdef RTMEMALLOC_EXEC_HEAP
248 if (g_HeapExec != NIL_RTHEAPSIMPLE)
249 {
250 RTSpinlockAcquire(g_HeapExecSpinlock);
251 pHdr = (PRTMEMHDR)RTHeapSimpleAlloc(g_HeapExec, cb + sizeof(*pHdr), 0);
252 RTSpinlockRelease(g_HeapExecSpinlock);
253 fFlags |= RTMEMHDR_FLAG_EXEC_HEAP;
254 }
255 else
256 pHdr = NULL;
257
258# elif defined(RTMEMALLOC_EXEC_VM_AREA)
259 pHdr = rtR0MemAllocExecVmArea(cb);
260 fFlags |= RTMEMHDR_FLAG_EXEC_VM_AREA;
261
262# else /* !RTMEMALLOC_EXEC_HEAP */
263# error "you don not want to go here..."
264 pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, MY_PAGE_KERNEL_EXEC);
265# endif /* !RTMEMALLOC_EXEC_HEAP */
266
267#elif defined(PAGE_KERNEL_EXEC) && defined(CONFIG_X86_PAE)
268 pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, MY_PAGE_KERNEL_EXEC);
269#else
270 pHdr = (PRTMEMHDR)vmalloc(cb + sizeof(*pHdr));
271#endif
272 }
273 else
274 {
275 if (
276#if 1 /* vmalloc has serious performance issues, avoid it. */
277 cb <= PAGE_SIZE*16 - sizeof(*pHdr)
278#else
279 cb <= PAGE_SIZE
280#endif
281 || (fFlags & RTMEMHDR_FLAG_ANY_CTX)
282 )
283 {
284 fFlags |= RTMEMHDR_FLAG_KMALLOC;
285 pHdr = kmalloc(cb + sizeof(*pHdr),
286 (fFlags & RTMEMHDR_FLAG_ANY_CTX_ALLOC) ? (GFP_ATOMIC | __GFP_NOWARN)
287 : (GFP_KERNEL | __GFP_NOWARN));
288 if (RT_UNLIKELY( !pHdr
289 && cb > PAGE_SIZE
290 && !(fFlags & RTMEMHDR_FLAG_ANY_CTX) ))
291 {
292 fFlags &= ~RTMEMHDR_FLAG_KMALLOC;
293 pHdr = vmalloc(cb + sizeof(*pHdr));
294 }
295 }
296 else
297 pHdr = vmalloc(cb + sizeof(*pHdr));
298 }
299 if (RT_UNLIKELY(!pHdr))
300 return VERR_NO_MEMORY;
301
302 /*
303 * Initialize.
304 */
305 pHdr->u32Magic = RTMEMHDR_MAGIC;
306 pHdr->fFlags = fFlags;
307 pHdr->cb = cb;
308 pHdr->cbReq = cb;
309
310 *ppHdr = pHdr;
311 return VINF_SUCCESS;
312}
313
314
315/**
316 * OS specific free function.
317 */
318DECLHIDDEN(void) rtR0MemFree(PRTMEMHDR pHdr)
319{
320 pHdr->u32Magic += 1;
321 if (pHdr->fFlags & RTMEMHDR_FLAG_KMALLOC)
322 kfree(pHdr);
323#ifdef RTMEMALLOC_EXEC_HEAP
324 else if (pHdr->fFlags & RTMEMHDR_FLAG_EXEC_HEAP)
325 {
326 RTSpinlockAcquire(g_HeapExecSpinlock);
327 RTHeapSimpleFree(g_HeapExec, pHdr);
328 RTSpinlockRelease(g_HeapExecSpinlock);
329 }
330#endif
331#ifdef RTMEMALLOC_EXEC_VM_AREA
332 else if (pHdr->fFlags & RTMEMHDR_FLAG_EXEC_VM_AREA)
333 {
334 PRTMEMLNXHDREX pHdrEx = RT_FROM_MEMBER(pHdr, RTMEMLNXHDREX, Hdr);
335 size_t iPage = pHdrEx->pVmArea->nr_pages;
336 struct page **papPages = pHdrEx->pVmArea->pages;
337 void *pvMapping = pHdrEx->pVmArea->addr;
338
339 vunmap(pvMapping);
340
341 while (iPage-- > 0)
342 __free_page(papPages[iPage]);
343 kfree(papPages);
344 }
345#endif
346 else
347 vfree(pHdr);
348}
349
350
351
352/**
353 * Compute order. Some functions allocate 2^order pages.
354 *
355 * @returns order.
356 * @param cPages Number of pages.
357 */
358static int CalcPowerOf2Order(unsigned long cPages)
359{
360 int iOrder;
361 unsigned long cTmp;
362
363 for (iOrder = 0, cTmp = cPages; cTmp >>= 1; ++iOrder)
364 ;
365 if (cPages & ~(1 << iOrder))
366 ++iOrder;
367
368 return iOrder;
369}
370
371
372/**
373 * Allocates physical contiguous memory (below 4GB).
374 * The allocation is page aligned and the content is undefined.
375 *
376 * @returns Pointer to the memory block. This is page aligned.
377 * @param pPhys Where to store the physical address.
378 * @param cb The allocation size in bytes. This is always
379 * rounded up to PAGE_SIZE.
380 */
381RTR0DECL(void *) RTMemContAlloc(PRTCCPHYS pPhys, size_t cb)
382{
383 int cOrder;
384 unsigned cPages;
385 struct page *paPages;
386
387 /*
388 * validate input.
389 */
390 Assert(VALID_PTR(pPhys));
391 Assert(cb > 0);
392
393 /*
394 * Allocate page pointer array.
395 */
396 cb = RT_ALIGN_Z(cb, PAGE_SIZE);
397 cPages = cb >> PAGE_SHIFT;
398 cOrder = CalcPowerOf2Order(cPages);
399#if (defined(RT_ARCH_AMD64) || defined(CONFIG_X86_PAE)) && defined(GFP_DMA32)
400 /* ZONE_DMA32: 0-4GB */
401 paPages = alloc_pages(GFP_DMA32 | __GFP_NOWARN, cOrder);
402 if (!paPages)
403#endif
404#ifdef RT_ARCH_AMD64
405 /* ZONE_DMA; 0-16MB */
406 paPages = alloc_pages(GFP_DMA | __GFP_NOWARN, cOrder);
407#else
408 /* ZONE_NORMAL: 0-896MB */
409 paPages = alloc_pages(GFP_USER | __GFP_NOWARN, cOrder);
410#endif
411 if (paPages)
412 {
413 /*
414 * Reserve the pages and mark them executable.
415 */
416 unsigned iPage;
417 for (iPage = 0; iPage < cPages; iPage++)
418 {
419 Assert(!PageHighMem(&paPages[iPage]));
420 if (iPage + 1 < cPages)
421 {
422 AssertMsg( (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage])) + PAGE_SIZE
423 == (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage + 1]))
424 && page_to_phys(&paPages[iPage]) + PAGE_SIZE
425 == page_to_phys(&paPages[iPage + 1]),
426 ("iPage=%i cPages=%u [0]=%#llx,%p [1]=%#llx,%p\n", iPage, cPages,
427 (long long)page_to_phys(&paPages[iPage]), phys_to_virt(page_to_phys(&paPages[iPage])),
428 (long long)page_to_phys(&paPages[iPage + 1]), phys_to_virt(page_to_phys(&paPages[iPage + 1])) ));
429 }
430
431 SetPageReserved(&paPages[iPage]);
432#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */
433 MY_SET_PAGES_EXEC(&paPages[iPage], 1);
434#endif
435 }
436 *pPhys = page_to_phys(paPages);
437 return phys_to_virt(page_to_phys(paPages));
438 }
439
440 return NULL;
441}
442RT_EXPORT_SYMBOL(RTMemContAlloc);
443
444
445/**
446 * Frees memory allocated using RTMemContAlloc().
447 *
448 * @param pv Pointer to return from RTMemContAlloc().
449 * @param cb The cb parameter passed to RTMemContAlloc().
450 */
451RTR0DECL(void) RTMemContFree(void *pv, size_t cb)
452{
453 if (pv)
454 {
455 int cOrder;
456 unsigned cPages;
457 unsigned iPage;
458 struct page *paPages;
459
460 /* validate */
461 AssertMsg(!((uintptr_t)pv & PAGE_OFFSET_MASK), ("pv=%p\n", pv));
462 Assert(cb > 0);
463
464 /* calc order and get pages */
465 cb = RT_ALIGN_Z(cb, PAGE_SIZE);
466 cPages = cb >> PAGE_SHIFT;
467 cOrder = CalcPowerOf2Order(cPages);
468 paPages = virt_to_page(pv);
469
470 /*
471 * Restore page attributes freeing the pages.
472 */
473 for (iPage = 0; iPage < cPages; iPage++)
474 {
475 ClearPageReserved(&paPages[iPage]);
476#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */
477 MY_SET_PAGES_NOEXEC(&paPages[iPage], 1);
478#endif
479 }
480 __free_pages(paPages, cOrder);
481 }
482}
483RT_EXPORT_SYMBOL(RTMemContFree);
484
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