diff options
Diffstat (limited to 'src/VBox/Runtime/r0drv/linux/alloc-r0drv-linux.c')
| -rw-r--r-- | src/VBox/Runtime/r0drv/linux/alloc-r0drv-linux.c | 497 |
1 files changed, 497 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r0drv/linux/alloc-r0drv-linux.c b/src/VBox/Runtime/r0drv/linux/alloc-r0drv-linux.c new file mode 100644 index 00000000..1ae48f9f --- /dev/null +++ b/src/VBox/Runtime/r0drv/linux/alloc-r0drv-linux.c @@ -0,0 +1,497 @@ +/* $Id: alloc-r0drv-linux.c $ */ +/** @file + * IPRT - Memory Allocation, Ring-0 Driver, Linux. + */ + +/* + * Copyright (C) 2006-2020 Oracle Corporation + * + * This file is part of VirtualBox Open Source Edition (OSE), as + * available from http://www.virtualbox.org. This file is free software; + * you can redistribute it and/or modify it under the terms of the GNU + * General Public License (GPL) as published by the Free Software + * Foundation, in version 2 as it comes in the "COPYING" file of the + * VirtualBox OSE distribution. VirtualBox OSE is distributed in the + * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL) only, as it comes in the "COPYING.CDDL" file of the + * VirtualBox OSE distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#include "the-linux-kernel.h" +#include "internal/iprt.h" +#include <iprt/mem.h> + +#include <iprt/assert.h> +#include <iprt/errcore.h> +#include "r0drv/alloc-r0drv.h" + + +#if (defined(RT_ARCH_AMD64) || defined(DOXYGEN_RUNNING)) && !defined(RTMEMALLOC_EXEC_HEAP) +# if RTLNX_VER_MIN(2,6,23) && RTLNX_VER_MAX(5,8,0) +/** + * Starting with 2.6.23 we can use __get_vm_area and map_vm_area to allocate + * memory in the moduel range. This is preferrable to the exec heap below. + */ +# define RTMEMALLOC_EXEC_VM_AREA +# else +/** + * We need memory in the module range (~2GB to ~0) this can only be obtained + * thru APIs that are not exported (see module_alloc()). + * + * So, we'll have to create a quick and dirty heap here using BSS memory. + * Very annoying and it's going to restrict us! + */ +# define RTMEMALLOC_EXEC_HEAP +# endif +#endif + +#ifdef RTMEMALLOC_EXEC_HEAP +# include <iprt/heap.h> +# include <iprt/spinlock.h> +# include <iprt/errcore.h> +#endif + +#include "internal/initterm.h" + + +/********************************************************************************************************************************* +* Structures and Typedefs * +*********************************************************************************************************************************/ +#ifdef RTMEMALLOC_EXEC_VM_AREA +/** + * Extended header used for headers marked with RTMEMHDR_FLAG_EXEC_VM_AREA. + * + * This is used with allocating executable memory, for things like generated + * code and loaded modules. + */ +typedef struct RTMEMLNXHDREX +{ + /** The VM area for this allocation. */ + struct vm_struct *pVmArea; + void *pvDummy; + /** The header we present to the generic API. */ + RTMEMHDR Hdr; +} RTMEMLNXHDREX; +AssertCompileSize(RTMEMLNXHDREX, 32); +/** Pointer to an extended memory header. */ +typedef RTMEMLNXHDREX *PRTMEMLNXHDREX; +#endif + + +/********************************************************************************************************************************* +* Global Variables * +*********************************************************************************************************************************/ +#ifdef RTMEMALLOC_EXEC_HEAP +/** The heap. */ +static RTHEAPSIMPLE g_HeapExec = NIL_RTHEAPSIMPLE; +/** Spinlock protecting the heap. */ +static RTSPINLOCK g_HeapExecSpinlock = NIL_RTSPINLOCK; +#endif + + +/** + * API for cleaning up the heap spinlock on IPRT termination. + * This is as RTMemExecDonate specific to AMD64 Linux/GNU. + */ +DECLHIDDEN(void) rtR0MemExecCleanup(void) +{ +#ifdef RTMEMALLOC_EXEC_HEAP + RTSpinlockDestroy(g_HeapExecSpinlock); + g_HeapExecSpinlock = NIL_RTSPINLOCK; +#endif +} + + +/** + * Donate read+write+execute memory to the exec heap. + * + * This API is specific to AMD64 and Linux/GNU. A kernel module that desires to + * use RTMemExecAlloc on AMD64 Linux/GNU will have to donate some statically + * allocated memory in the module if it wishes for GCC generated code to work. + * GCC can only generate modules that work in the address range ~2GB to ~0 + * currently. + * + * The API only accept one single donation. + * + * @returns IPRT status code. + * @retval VERR_NOT_SUPPORTED if the code isn't enabled. + * @param pvMemory Pointer to the memory block. + * @param cb The size of the memory block. + */ +RTR0DECL(int) RTR0MemExecDonate(void *pvMemory, size_t cb) +{ +#ifdef RTMEMALLOC_EXEC_HEAP + int rc; + AssertReturn(g_HeapExec == NIL_RTHEAPSIMPLE, VERR_WRONG_ORDER); + + rc = RTSpinlockCreate(&g_HeapExecSpinlock, RTSPINLOCK_FLAGS_INTERRUPT_SAFE, "RTR0MemExecDonate"); + if (RT_SUCCESS(rc)) + { + rc = RTHeapSimpleInit(&g_HeapExec, pvMemory, cb); + if (RT_FAILURE(rc)) + rtR0MemExecCleanup(); + } + return rc; +#else + RT_NOREF_PV(pvMemory); RT_NOREF_PV(cb); + return VERR_NOT_SUPPORTED; +#endif +} +RT_EXPORT_SYMBOL(RTR0MemExecDonate); + + + +#ifdef RTMEMALLOC_EXEC_VM_AREA +/** + * Allocate executable kernel memory in the module range. + * + * @returns Pointer to a allocation header success. NULL on failure. + * + * @param cb The size the user requested. + */ +static PRTMEMHDR rtR0MemAllocExecVmArea(size_t cb) +{ + size_t const cbAlloc = RT_ALIGN_Z(sizeof(RTMEMLNXHDREX) + cb, PAGE_SIZE); + size_t const cPages = cbAlloc >> PAGE_SHIFT; + struct page **papPages; + struct vm_struct *pVmArea; + size_t iPage; + + pVmArea = __get_vm_area(cbAlloc, VM_ALLOC, MODULES_VADDR, MODULES_END); + if (!pVmArea) + return NULL; + pVmArea->nr_pages = 0; /* paranoia? */ + pVmArea->pages = NULL; /* paranoia? */ + + papPages = (struct page **)kmalloc(cPages * sizeof(papPages[0]), GFP_KERNEL | __GFP_NOWARN); + if (!papPages) + { + vunmap(pVmArea->addr); + return NULL; + } + + for (iPage = 0; iPage < cPages; iPage++) + { + papPages[iPage] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN); + if (!papPages[iPage]) + break; + } + if (iPage == cPages) + { + /* + * Map the pages. + * + * Not entirely sure we really need to set nr_pages and pages here, but + * they provide a very convenient place for storing something we need + * in the free function, if nothing else... + */ +# if RTLNX_VER_MAX(3,17,0) + struct page **papPagesIterator = papPages; +# endif + pVmArea->nr_pages = cPages; + pVmArea->pages = papPages; + if (!map_vm_area(pVmArea, PAGE_KERNEL_EXEC, +# if RTLNX_VER_MAX(3,17,0) + &papPagesIterator +# else + papPages +# endif + )) + { + PRTMEMLNXHDREX pHdrEx = (PRTMEMLNXHDREX)pVmArea->addr; + pHdrEx->pVmArea = pVmArea; + pHdrEx->pvDummy = NULL; + return &pHdrEx->Hdr; + } + /* bail out */ +# if RTLNX_VER_MAX(3,17,0) + pVmArea->nr_pages = papPagesIterator - papPages; +# endif + } + + vunmap(pVmArea->addr); + + while (iPage-- > 0) + __free_page(papPages[iPage]); + kfree(papPages); + + return NULL; +} +#endif /* RTMEMALLOC_EXEC_VM_AREA */ + + +/** + * OS specific allocation function. + */ +DECLHIDDEN(int) rtR0MemAllocEx(size_t cb, uint32_t fFlags, PRTMEMHDR *ppHdr) +{ + PRTMEMHDR pHdr; + IPRT_LINUX_SAVE_EFL_AC(); + + /* + * Allocate. + */ + if (fFlags & RTMEMHDR_FLAG_EXEC) + { + if (fFlags & RTMEMHDR_FLAG_ANY_CTX) + return VERR_NOT_SUPPORTED; + +#if defined(RT_ARCH_AMD64) +# ifdef RTMEMALLOC_EXEC_HEAP + if (g_HeapExec != NIL_RTHEAPSIMPLE) + { + RTSpinlockAcquire(g_HeapExecSpinlock); + pHdr = (PRTMEMHDR)RTHeapSimpleAlloc(g_HeapExec, cb + sizeof(*pHdr), 0); + RTSpinlockRelease(g_HeapExecSpinlock); + fFlags |= RTMEMHDR_FLAG_EXEC_HEAP; + } + else + pHdr = NULL; + +# elif defined(RTMEMALLOC_EXEC_VM_AREA) + pHdr = rtR0MemAllocExecVmArea(cb); + fFlags |= RTMEMHDR_FLAG_EXEC_VM_AREA; + +# else /* !RTMEMALLOC_EXEC_HEAP */ +# error "you don not want to go here..." + pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, MY_PAGE_KERNEL_EXEC); +# endif /* !RTMEMALLOC_EXEC_HEAP */ + +#elif defined(PAGE_KERNEL_EXEC) && defined(CONFIG_X86_PAE) + pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, MY_PAGE_KERNEL_EXEC); +#else + pHdr = (PRTMEMHDR)vmalloc(cb + sizeof(*pHdr)); +#endif + } + else + { + if ( +#if 1 /* vmalloc has serious performance issues, avoid it. */ + cb <= PAGE_SIZE*16 - sizeof(*pHdr) +#else + cb <= PAGE_SIZE +#endif + || (fFlags & RTMEMHDR_FLAG_ANY_CTX) + ) + { + fFlags |= RTMEMHDR_FLAG_KMALLOC; + pHdr = kmalloc(cb + sizeof(*pHdr), + (fFlags & RTMEMHDR_FLAG_ANY_CTX_ALLOC) ? (GFP_ATOMIC | __GFP_NOWARN) + : (GFP_KERNEL | __GFP_NOWARN)); + if (RT_UNLIKELY( !pHdr + && cb > PAGE_SIZE + && !(fFlags & RTMEMHDR_FLAG_ANY_CTX) )) + { + fFlags &= ~RTMEMHDR_FLAG_KMALLOC; + pHdr = vmalloc(cb + sizeof(*pHdr)); + } + } + else + pHdr = vmalloc(cb + sizeof(*pHdr)); + } + if (RT_UNLIKELY(!pHdr)) + { + IPRT_LINUX_RESTORE_EFL_AC(); + return VERR_NO_MEMORY; + } + + /* + * Initialize. + */ + pHdr->u32Magic = RTMEMHDR_MAGIC; + pHdr->fFlags = fFlags; + pHdr->cb = cb; + pHdr->cbReq = cb; + + *ppHdr = pHdr; + IPRT_LINUX_RESTORE_EFL_AC(); + return VINF_SUCCESS; +} + + +/** + * OS specific free function. + */ +DECLHIDDEN(void) rtR0MemFree(PRTMEMHDR pHdr) +{ + IPRT_LINUX_SAVE_EFL_AC(); + + pHdr->u32Magic += 1; + if (pHdr->fFlags & RTMEMHDR_FLAG_KMALLOC) + kfree(pHdr); +#ifdef RTMEMALLOC_EXEC_HEAP + else if (pHdr->fFlags & RTMEMHDR_FLAG_EXEC_HEAP) + { + RTSpinlockAcquire(g_HeapExecSpinlock); + RTHeapSimpleFree(g_HeapExec, pHdr); + RTSpinlockRelease(g_HeapExecSpinlock); + } +#endif +#ifdef RTMEMALLOC_EXEC_VM_AREA + else if (pHdr->fFlags & RTMEMHDR_FLAG_EXEC_VM_AREA) + { + PRTMEMLNXHDREX pHdrEx = RT_FROM_MEMBER(pHdr, RTMEMLNXHDREX, Hdr); + size_t iPage = pHdrEx->pVmArea->nr_pages; + struct page **papPages = pHdrEx->pVmArea->pages; + void *pvMapping = pHdrEx->pVmArea->addr; + + vunmap(pvMapping); + + while (iPage-- > 0) + __free_page(papPages[iPage]); + kfree(papPages); + } +#endif + else + vfree(pHdr); + + IPRT_LINUX_RESTORE_EFL_AC(); +} + + + +/** + * Compute order. Some functions allocate 2^order pages. + * + * @returns order. + * @param cPages Number of pages. + */ +static int CalcPowerOf2Order(unsigned long cPages) +{ + int iOrder; + unsigned long cTmp; + + for (iOrder = 0, cTmp = cPages; cTmp >>= 1; ++iOrder) + ; + if (cPages & ~(1 << iOrder)) + ++iOrder; + + return iOrder; +} + + +/** + * Allocates physical contiguous memory (below 4GB). + * The allocation is page aligned and the content is undefined. + * + * @returns Pointer to the memory block. This is page aligned. + * @param pPhys Where to store the physical address. + * @param cb The allocation size in bytes. This is always + * rounded up to PAGE_SIZE. + */ +RTR0DECL(void *) RTMemContAlloc(PRTCCPHYS pPhys, size_t cb) +{ + int cOrder; + unsigned cPages; + struct page *paPages; + void *pvRet; + IPRT_LINUX_SAVE_EFL_AC(); + + /* + * validate input. + */ + Assert(VALID_PTR(pPhys)); + Assert(cb > 0); + + /* + * Allocate page pointer array. + */ + cb = RT_ALIGN_Z(cb, PAGE_SIZE); + cPages = cb >> PAGE_SHIFT; + cOrder = CalcPowerOf2Order(cPages); +#if (defined(RT_ARCH_AMD64) || defined(CONFIG_X86_PAE)) && defined(GFP_DMA32) + /* ZONE_DMA32: 0-4GB */ + paPages = alloc_pages(GFP_DMA32 | __GFP_NOWARN, cOrder); + if (!paPages) +#endif +#ifdef RT_ARCH_AMD64 + /* ZONE_DMA; 0-16MB */ + paPages = alloc_pages(GFP_DMA | __GFP_NOWARN, cOrder); +#else + /* ZONE_NORMAL: 0-896MB */ + paPages = alloc_pages(GFP_USER | __GFP_NOWARN, cOrder); +#endif + if (paPages) + { + /* + * Reserve the pages and mark them executable. + */ + unsigned iPage; + for (iPage = 0; iPage < cPages; iPage++) + { + Assert(!PageHighMem(&paPages[iPage])); + if (iPage + 1 < cPages) + { + AssertMsg( (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage])) + PAGE_SIZE + == (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage + 1])) + && page_to_phys(&paPages[iPage]) + PAGE_SIZE + == page_to_phys(&paPages[iPage + 1]), + ("iPage=%i cPages=%u [0]=%#llx,%p [1]=%#llx,%p\n", iPage, cPages, + (long long)page_to_phys(&paPages[iPage]), phys_to_virt(page_to_phys(&paPages[iPage])), + (long long)page_to_phys(&paPages[iPage + 1]), phys_to_virt(page_to_phys(&paPages[iPage + 1])) )); + } + + SetPageReserved(&paPages[iPage]); + } + *pPhys = page_to_phys(paPages); + pvRet = phys_to_virt(page_to_phys(paPages)); + } + else + pvRet = NULL; + + IPRT_LINUX_RESTORE_EFL_AC(); + return pvRet; +} +RT_EXPORT_SYMBOL(RTMemContAlloc); + + +/** + * Frees memory allocated using RTMemContAlloc(). + * + * @param pv Pointer to return from RTMemContAlloc(). + * @param cb The cb parameter passed to RTMemContAlloc(). + */ +RTR0DECL(void) RTMemContFree(void *pv, size_t cb) +{ + if (pv) + { + int cOrder; + unsigned cPages; + unsigned iPage; + struct page *paPages; + IPRT_LINUX_SAVE_EFL_AC(); + + /* validate */ + AssertMsg(!((uintptr_t)pv & PAGE_OFFSET_MASK), ("pv=%p\n", pv)); + Assert(cb > 0); + + /* calc order and get pages */ + cb = RT_ALIGN_Z(cb, PAGE_SIZE); + cPages = cb >> PAGE_SHIFT; + cOrder = CalcPowerOf2Order(cPages); + paPages = virt_to_page(pv); + + /* + * Restore page attributes freeing the pages. + */ + for (iPage = 0; iPage < cPages; iPage++) + { + ClearPageReserved(&paPages[iPage]); + } + __free_pages(paPages, cOrder); + IPRT_LINUX_RESTORE_EFL_AC(); + } +} +RT_EXPORT_SYMBOL(RTMemContFree); + |