alloc-r0drv-linux.c revision 5eda82e218d35ae0691febd531e1bfc0324cc4a6
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * IPRT - Memory Allocation, Ring-0 Driver, Linux.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * Copyright (C) 2006-2010 Oracle Corporation
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * This file is part of VirtualBox Open Source Edition (OSE), as
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * available from http://www.virtualbox.org. This file is free software;
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * you can redistribute it and/or modify it under the terms of the GNU
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * General Public License (GPL) as published by the Free Software
c58f1213e628a545081c70e26c6b67a841cff880vboxsync * Foundation, in version 2 as it comes in the "COPYING" file of the
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * The contents of this file may alternatively be used under the terms
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * of the Common Development and Distribution License Version 1.0
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * VirtualBox OSE distribution, in which case the provisions of the
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * CDDL are applicable instead of those of the GPL.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * You may elect to license modified versions of this file under the
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * terms and conditions of either the GPL or the CDDL or both.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync/*******************************************************************************
7bfdc833786b0261c468584470b4c98005500ab2vboxsync* Header Files *
7bfdc833786b0261c468584470b4c98005500ab2vboxsync*******************************************************************************/
a853f8415aaf07b63c0f6b5b7e5b222a915b868evboxsync#if defined(RT_ARCH_AMD64) || defined(DOXYGEN_RUNNING)
11f2a7716fda50c475f49969f484b00d3fef3be2vboxsync * We need memory in the module range (~2GB to ~0) this can only be obtained
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * thru APIs that are not exported (see module_alloc()).
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * So, we'll have to create a quick and dirty heap here using BSS memory.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * Very annoying and it's going to restrict us!
7bfdc833786b0261c468584470b4c98005500ab2vboxsync/*******************************************************************************
7bfdc833786b0261c468584470b4c98005500ab2vboxsync* Global Variables *
7bfdc833786b0261c468584470b4c98005500ab2vboxsync*******************************************************************************/
7bfdc833786b0261c468584470b4c98005500ab2vboxsync/** The heap. */
7bfdc833786b0261c468584470b4c98005500ab2vboxsync/** Spinlock protecting the heap. */
7bfdc833786b0261c468584470b4c98005500ab2vboxsyncstatic RTSPINLOCK g_HeapExecSpinlock = NIL_RTSPINLOCK;
7bfdc833786b0261c468584470b4c98005500ab2vboxsyncstatic void *g_pvHeap;
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * API for cleaning up the heap spinlock on IPRT termination.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * This is as RTMemExecDonate specific to AMD64 Linux/GNU.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync unsigned i;
7bfdc833786b0261c468584470b4c98005500ab2vboxsync /* according to linux/drivers/lguest/core.c this function undoes
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * map_vm_area() as well as __get_vm_area(). */
7bfdc833786b0261c468584470b4c98005500ab2vboxsync for (i = 0; i < g_cPages; i++)
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * Donate read+write+execute memory to the exec heap.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * This API is specific to AMD64 and Linux/GNU. A kernel module that desires to
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * use RTMemExecAlloc on AMD64 Linux/GNU will have to donate some statically
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * allocated memory in the module if it wishes for GCC generated code to work.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * GCC can only generate modules that work in the address range ~2GB to ~0
11f2a7716fda50c475f49969f484b00d3fef3be2vboxsync * currently.
11f2a7716fda50c475f49969f484b00d3fef3be2vboxsync * The API only accept one single donation.
11f2a7716fda50c475f49969f484b00d3fef3be2vboxsync * @returns IPRT status code.
11f2a7716fda50c475f49969f484b00d3fef3be2vboxsync * @param pvMemory Pointer to the memory block.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * @param cb The size of the memory block.
11f2a7716fda50c475f49969f484b00d3fef3be2vboxsyncRTR0DECL(int) RTR0MemExecDonate(void *pvMemory, size_t cb)
7bfdc833786b0261c468584470b4c98005500ab2vboxsync AssertReturn(g_HeapExec == NIL_RTHEAPSIMPLE, VERR_WRONG_ORDER);
7bfdc833786b0261c468584470b4c98005500ab2vboxsync# else /* !RTMEMALLOC_EXEC_HEAP_VM_AREA */
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * RTR0MemExecDonate() does not work if CONFIG_DEBUG_SET_MODULE_RONX is enabled.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * In that case, allocate a VM area in the modules range and back it with kernel
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * memory. Unfortunately __vmalloc_area() is not exported so we have to emulate
7bfdc833786b0261c468584470b4c98005500ab2vboxsync unsigned i;
7bfdc833786b0261c468584470b4c98005500ab2vboxsync AssertReturn(g_HeapExec == NIL_RTHEAPSIMPLE, VERR_WRONG_ORDER);
ec733c67fa9e0b1b9c63dcfad341ce7c3f573f63vboxsync area = __get_vm_area(cb, VM_ALLOC, MODULES_VADDR, MODULES_END);
7bfdc833786b0261c468584470b4c98005500ab2vboxsync for (i = 0; i < cPages; i++)
7bfdc833786b0261c468584470b4c98005500ab2vboxsync g_apPages[i] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
2f97ca84d7747f5f93c00908ddfbf9848f17653dvboxsync# endif /* RTMEMALLOC_EXEC_HEAP_VM_AREA */
7bfdc833786b0261c468584470b4c98005500ab2vboxsync#endif /* RTMEMALLOC_EXEC_HEAP */
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * OS specific allocation function.
7bfdc833786b0261c468584470b4c98005500ab2vboxsyncDECLHIDDEN(int) rtR0MemAllocEx(size_t cb, uint32_t fFlags, PRTMEMHDR *ppHdr)
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * Allocate.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync RTSPINLOCKTMP SpinlockTmp = RTSPINLOCKTMP_INITIALIZER;
7bfdc833786b0261c468584470b4c98005500ab2vboxsync RTSpinlockAcquireNoInts(g_HeapExecSpinlock, &SpinlockTmp);
a853f8415aaf07b63c0f6b5b7e5b222a915b868evboxsync pHdr = (PRTMEMHDR)RTHeapSimpleAlloc(g_HeapExec, cb + sizeof(*pHdr), 0);
7bfdc833786b0261c468584470b4c98005500ab2vboxsync RTSpinlockReleaseNoInts(g_HeapExecSpinlock, &SpinlockTmp);
7bfdc833786b0261c468584470b4c98005500ab2vboxsync# else /* !RTMEMALLOC_EXEC_HEAP */
7bfdc833786b0261c468584470b4c98005500ab2vboxsync pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL | __GFP_HIGHMEM, MY_PAGE_KERNEL_EXEC);
7bfdc833786b0261c468584470b4c98005500ab2vboxsync# endif /* !RTMEMALLOC_EXEC_HEAP */
7bfdc833786b0261c468584470b4c98005500ab2vboxsync#elif defined(PAGE_KERNEL_EXEC) && defined(CONFIG_X86_PAE)
7bfdc833786b0261c468584470b4c98005500ab2vboxsync pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL | __GFP_HIGHMEM, MY_PAGE_KERNEL_EXEC);
7bfdc833786b0261c468584470b4c98005500ab2vboxsync if (cb <= PAGE_SIZE || (fFlags & RTMEMHDR_FLAG_ANY_CTX))
7bfdc833786b0261c468584470b4c98005500ab2vboxsync (fFlags & RTMEMHDR_FLAG_ANY_CTX_ALLOC) ? GFP_ATOMIC : GFP_KERNEL);
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * Initialize.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * OS specific free function.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync RTSPINLOCKTMP SpinlockTmp = RTSPINLOCKTMP_INITIALIZER;
7bfdc833786b0261c468584470b4c98005500ab2vboxsync RTSpinlockAcquireNoInts(g_HeapExecSpinlock, &SpinlockTmp);
7bfdc833786b0261c468584470b4c98005500ab2vboxsync RTSpinlockReleaseNoInts(g_HeapExecSpinlock, &SpinlockTmp);
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * Compute order. Some functions allocate 2^order pages.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * @returns order.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * @param cPages Number of pages.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync unsigned long cTmp;
2f97ca84d7747f5f93c00908ddfbf9848f17653dvboxsync for (iOrder = 0, cTmp = cPages; cTmp >>= 1; ++iOrder)
2f97ca84d7747f5f93c00908ddfbf9848f17653dvboxsync * Allocates physical contiguous memory (below 4GB).
920730ce664b646eea6da4219b93030b1ee32405vboxsync * The allocation is page aligned and the content is undefined.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * @returns Pointer to the memory block. This is page aligned.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * @param pPhys Where to store the physical address.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * @param cb The allocation size in bytes. This is always
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * rounded up to PAGE_SIZE.
a853f8415aaf07b63c0f6b5b7e5b222a915b868evboxsyncRTR0DECL(void *) RTMemContAlloc(PRTCCPHYS pPhys, size_t cb)
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * validate input.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * Allocate page pointer array.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync#if (defined(RT_ARCH_AMD64) || defined(CONFIG_X86_PAE)) && defined(GFP_DMA32)
7bfdc833786b0261c468584470b4c98005500ab2vboxsync /* ZONE_DMA32: 0-4GB */
7bfdc833786b0261c468584470b4c98005500ab2vboxsync /* ZONE_DMA; 0-16MB */
7bfdc833786b0261c468584470b4c98005500ab2vboxsync /* ZONE_NORMAL: 0-896MB */
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * Reserve the pages and mark them executable.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync AssertMsg( (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage])) + PAGE_SIZE
7bfdc833786b0261c468584470b4c98005500ab2vboxsync == (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage + 1]))
7bfdc833786b0261c468584470b4c98005500ab2vboxsync ("iPage=%i cPages=%u [0]=%#llx,%p [1]=%#llx,%p\n", iPage, cPages,
a853f8415aaf07b63c0f6b5b7e5b222a915b868evboxsync (long long)page_to_phys(&paPages[iPage]), phys_to_virt(page_to_phys(&paPages[iPage])),
7bfdc833786b0261c468584470b4c98005500ab2vboxsync (long long)page_to_phys(&paPages[iPage + 1]), phys_to_virt(page_to_phys(&paPages[iPage + 1])) ));
7bfdc833786b0261c468584470b4c98005500ab2vboxsync#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * Frees memory allocated ysing RTMemContAlloc().
2f97ca84d7747f5f93c00908ddfbf9848f17653dvboxsync * @param pv Pointer to return from RTMemContAlloc().
2f97ca84d7747f5f93c00908ddfbf9848f17653dvboxsync * @param cb The cb parameter passed to RTMemContAlloc().
2f97ca84d7747f5f93c00908ddfbf9848f17653dvboxsync /* validate */
7bfdc833786b0261c468584470b4c98005500ab2vboxsync AssertMsg(!((uintptr_t)pv & PAGE_OFFSET_MASK), ("pv=%p\n", pv));
7bfdc833786b0261c468584470b4c98005500ab2vboxsync /* calc order and get pages */
7bfdc833786b0261c468584470b4c98005500ab2vboxsync * Restore page attributes freeing the pages.
7bfdc833786b0261c468584470b4c98005500ab2vboxsync#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */