diff options
Diffstat (limited to 'src/VBox/Runtime/r0drv/linux/memuserkernel-r0drv-linux.c')
| -rw-r--r-- | src/VBox/Runtime/r0drv/linux/memuserkernel-r0drv-linux.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r0drv/linux/memuserkernel-r0drv-linux.c b/src/VBox/Runtime/r0drv/linux/memuserkernel-r0drv-linux.c new file mode 100644 index 00000000..f23bd091 --- /dev/null +++ b/src/VBox/Runtime/r0drv/linux/memuserkernel-r0drv-linux.c @@ -0,0 +1,181 @@ +/* $Id: memuserkernel-r0drv-linux.c $ */ +/** @file + * IPRT - User & Kernel Memory, Ring-0 Driver, Linux. + */ + +/* + * Copyright (C) 2009-2020 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/errcore.h> + + +RTR0DECL(int) RTR0MemUserCopyFrom(void *pvDst, RTR3PTR R3PtrSrc, size_t cb) +{ + IPRT_LINUX_SAVE_EFL_AC(); + if (RT_LIKELY(copy_from_user(pvDst, (void *)R3PtrSrc, cb) == 0)) + { + IPRT_LINUX_RESTORE_EFL_AC(); + return VINF_SUCCESS; + } + IPRT_LINUX_RESTORE_EFL_AC(); + return VERR_ACCESS_DENIED; +} +RT_EXPORT_SYMBOL(RTR0MemUserCopyFrom); + + +RTR0DECL(int) RTR0MemUserCopyTo(RTR3PTR R3PtrDst, void const *pvSrc, size_t cb) +{ + IPRT_LINUX_SAVE_EFL_AC(); + if (RT_LIKELY(copy_to_user((void *)R3PtrDst, pvSrc, cb) == 0)) + { + IPRT_LINUX_RESTORE_EFL_AC(); + return VINF_SUCCESS; + } + IPRT_LINUX_RESTORE_EFL_AC(); + return VERR_ACCESS_DENIED; +} +RT_EXPORT_SYMBOL(RTR0MemUserCopyTo); + + +RTR0DECL(bool) RTR0MemUserIsValidAddr(RTR3PTR R3Ptr) +{ + IPRT_LINUX_SAVE_EFL_AC(); +#if RTLNX_VER_MIN(5,0,0) || RTLNX_RHEL_MIN(8,1) + bool fRc = access_ok((void *)R3Ptr, 1); +#else + bool fRc = access_ok(VERIFY_READ, (void *)R3Ptr, 1); +#endif + IPRT_LINUX_RESTORE_EFL_AC(); + return fRc; +} +RT_EXPORT_SYMBOL(RTR0MemUserIsValidAddr); + + +RTR0DECL(bool) RTR0MemKernelIsValidAddr(void *pv) +{ + /* Couldn't find a straight forward way of doing this... */ +#if defined(RT_ARCH_X86) && defined(CONFIG_X86_HIGH_ENTRY) + return true; /* ?? */ +#elif defined(RT_ARCH_X86) || defined(RT_ARCH_AMD64) + return (uintptr_t)pv >= PAGE_OFFSET; +#else +# error "PORT ME" +#if RTLNX_VER_MIN(5,0,0) || RTLNX_RHEL_MIN(8,1) + return !access_ok(pv, 1); +#else + return !access_ok(VERIFY_READ, pv, 1); +#endif +#endif +} +RT_EXPORT_SYMBOL(RTR0MemKernelIsValidAddr); + + +RTR0DECL(bool) RTR0MemAreKrnlAndUsrDifferent(void) +{ +#if defined(RT_ARCH_X86) && defined(CONFIG_X86_HIGH_ENTRY) /* ?? */ + return false; +#else + return true; +#endif +} +RT_EXPORT_SYMBOL(RTR0MemAreKrnlAndUsrDifferent); + + +/** + * Treats both source and destination as unsafe buffers. + */ +static int rtR0MemKernelCopyLnxWorker(void *pvDst, void const *pvSrc, size_t cb) +{ +#if RTLNX_VER_MIN(2,5,55) +/* _ASM_EXTABLE was introduced in 2.6.25 from what I can tell. Using #ifndef + here since it has to be a macro and you never know what someone might have + backported to an earlier kernel release. */ +# ifndef _ASM_EXTABLE +# if ARCH_BITS == 32 +# define _ASM_EXTABLE(a_Instr, a_Resume) \ + ".section __ex_table,\"a\"\n" \ + ".balign 4\n" \ + ".long " #a_Instr "\n" \ + ".long " #a_Resume "\n" \ + ".previous\n" +# else +# define _ASM_EXTABLE(a_Instr, a_Resume) \ + ".section __ex_table,\"a\"\n" \ + ".balign 8\n" \ + ".quad " #a_Instr "\n" \ + ".quad " #a_Resume "\n" \ + ".previous\n" +# endif +# endif /* !_ASM_EXTABLE */ + int rc; + IPRT_LINUX_SAVE_EFL_AC(); /* paranoia */ + if (!cb) + return VINF_SUCCESS; + + __asm__ __volatile__ ("cld\n" + "1:\n\t" + "rep; movsb\n" + "2:\n\t" + ".section .fixup,\"ax\"\n" + "3:\n\t" + "movl %4, %0\n\t" + "jmp 2b\n\t" + ".previous\n" + _ASM_EXTABLE(1b, 3b) + : "=r" (rc), + "=D" (pvDst), + "=S" (pvSrc), + "=c" (cb) + : "i" (VERR_ACCESS_DENIED), + "0" (VINF_SUCCESS), + "1" (pvDst), + "2" (pvSrc), + "3" (cb) + : "memory"); + IPRT_LINUX_RESTORE_EFL_AC(); + return rc; +#else + return VERR_NOT_SUPPORTED; +#endif +} + + +RTR0DECL(int) RTR0MemKernelCopyFrom(void *pvDst, void const *pvSrc, size_t cb) +{ + return rtR0MemKernelCopyLnxWorker(pvDst, pvSrc, cb); +} +RT_EXPORT_SYMBOL(RTR0MemKernelCopyFrom); + + +RTR0DECL(int) RTR0MemKernelCopyTo(void *pvDst, void const *pvSrc, size_t cb) +{ + return rtR0MemKernelCopyLnxWorker(pvDst, pvSrc, cb); +} +RT_EXPORT_SYMBOL(RTR0MemKernelCopyTo); + |