162 lines
3.7 KiB
C
162 lines
3.7 KiB
C
/*
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* Copyright (c) 2006-2023 Ali Mashtizadeh
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* All rights reserved.
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* Generic Copyin/Copyout routines
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*/
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#include <stdbool.h>
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#include <stdint.h>
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#include <errno.h>
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#include <sys/kassert.h>
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#include <machine/pmap.h>
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extern int copy_unsafe(void *to_addr, void *from_addr, uintptr_t len);
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extern int copystr_unsafe(void *to_addr, void *from_addr, uintptr_t len);
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/**
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* Copy_In --
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*
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* Safely copy memory from userspace. Prevents userspace pointers from
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* reading kernel memory.
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*
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* Side effects:
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* Kernel page fault may have occurred.
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*
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* @param [in] fromuser User address to copy from.
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* @param [in] tokernel Kernel address to copy to.
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* @param [in] len Length of the data to copy.
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*
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* @retval EFAULT if the address is invalid or causes a fault.
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*/
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int
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Copy_In(uintptr_t fromuser, void *tokernel, uintptr_t len)
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{
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if (len == 0)
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return 0;
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// Kernel space
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if (fromuser >= MEM_USERSPACE_TOP) {
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kprintf("Copy_In: address exceeds userspace top\n");
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return EFAULT;
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}
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// Wrap around
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if (len > (MEM_USERSPACE_TOP - fromuser)) {
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kprintf("Copy_In: length exceeds userspace top\n");
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return EFAULT;
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}
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return copy_unsafe(tokernel, (void *)fromuser, len);
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}
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/**
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* Copy_Out --
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*
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* Safely copy memory to userspace. Prevents userspace pointers from
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* writing kernel memory.
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*
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* Side effects:
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* Kernel page fault may have occurred.
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*
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* @param [in] fromkernel Kernel address to copy from.
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* @param [in] touser User address to copy to.
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* @param [in] len Length of the data to copy.
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*
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* @retval EFAULT if the address is invalid or causes a fault.
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*/
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int
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Copy_Out(void *fromkernel, uintptr_t touser, uintptr_t len)
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{
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if (len == 0)
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return 0;
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// Kernel space
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if (touser >= MEM_USERSPACE_TOP) {
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kprintf("Copy_Out: address exceeds userspace top\n");
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return EFAULT;
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}
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// Wrap around
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if (len > (MEM_USERSPACE_TOP - touser)) {
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kprintf("Copy_Out: length exceeds userspace top\n");
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return EFAULT;
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}
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return copy_unsafe((void *)touser, fromkernel, len);
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}
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/**
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* Copy_StrIn --
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*
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* Safely copy a string from userspace. Prevents userspace pointers from
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* reading kernel memory.
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*
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* Side effects:
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* Kernel page fault may have occurred.
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*
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* @param [in] fromuser User address to copy from.
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* @param [in] tokernel Kernel address to copy to.
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* @param [in] len Maximum string length.
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*
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* @retval EFAULT if the address is invalid or causes a fault.
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*/
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int
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Copy_StrIn(uintptr_t fromuser, void *tokernel, uintptr_t len)
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{
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if (len == 0)
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return 0;
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// Kernel space
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if (fromuser >= MEM_USERSPACE_TOP) {
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kprintf("Copy_StrIn: address exceeds userspace top\n");
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return EFAULT;
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}
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// Wrap around
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if (len > (MEM_USERSPACE_TOP - fromuser)) {
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kprintf("Copy_StrIn: length exceeds userspace top\n");
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return EFAULT;
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}
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return copystr_unsafe(tokernel, (void *)fromuser, len);
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}
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/**
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* Copy_StrOut --
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*
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* Safely copy a string to userspace. Prevents userspace pointers from
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* writing kernel memory.
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*
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* Side effects:
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* Kernel page fault may have occurred.
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*
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* @param [in] fromkernel Kernel address to copy from.
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* @param [in] touser User address to copy to.
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* @param [in] len Maximum string length.
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*
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* @retval EFAULT if the address is invalid or causes a fault.
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*/
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int
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Copy_StrOut(void *fromkernel, uintptr_t touser, uintptr_t len)
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{
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if (len == 0)
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return 0;
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// Kernel space
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if (touser >= MEM_USERSPACE_TOP) {
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kprintf("Copy_StrOut: address exceeds userspace top\n");
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return EFAULT;
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}
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// Wrap around
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if (len > (MEM_USERSPACE_TOP - touser)) {
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kprintf("Copy_StrOut: length exceeds userspace top\n");
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return EFAULT;
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}
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return copystr_unsafe((void *)touser, fromkernel, len);
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}
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