91 lines
1.8 KiB
C
91 lines
1.8 KiB
C
#include "uaccess.h"
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#include "assert.h"
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#include "errno.h"
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#include "minmax.h"
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#include "mmuContext.h"
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#include "paging.h"
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#include "process.h"
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#include "thread.h"
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#include "types.h"
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static int bindtoUserContext()
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{
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struct thread *currentThread;
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struct mmu_context *ctx;
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currentThread = getCurrentThread();
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assert(NULL != currentThread->process);
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/* Switch to the user's address space */
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ctx = processGetMMUContext(currentThread->process);
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return threadChangeCurrentContext(ctx);
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}
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static int unbindUserContext()
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{
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return threadChangeCurrentContext(NULL);
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}
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static int memcpyUserMemNoCheck(vaddr_t dest, vaddr_t src, size_t size)
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{
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int ret;
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ret = bindtoUserContext();
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if (ret != 0)
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return ret;
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memcpy((void *)dest, (void *)src, size);
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ret = unbindUserContext();
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if (ret != 0)
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return ret;
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return size;
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}
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int memcpyFromUser(vaddr_t to, uaddr_t from, size_t size)
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{
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if ((uint)from < PAGING_BASE_USER_ADDRESS)
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return -EPERM;
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if ((uint)from > PAGING_TOP_USER_ADDRESS - size)
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return -EPERM;
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return memcpyUserMemNoCheck(to, from, size);
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}
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static int strzcpyFromUserNoCheck(char *to, char *from, size_t size)
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{
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int ret;
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ret = bindtoUserContext();
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if (ret != 0)
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return ret;
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for (unsigned int i = 0; i < size; i++) {
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to[i] = from[i];
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if (from[i] == '\0')
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break;
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}
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if (size > 0)
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to[size - 1] = '\0';
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ret = unbindUserContext();
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if (ret != 0)
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return ret;
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return size;
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}
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int strzcpyFromUser(vaddr_t *to, uaddr_t *from, size_t size)
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{
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if ((uint)from < PAGING_BASE_USER_ADDRESS)
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return -EPERM;
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if ((uint)from > PAGING_TOP_USER_ADDRESS - size)
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return -EPERM;
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return strzcpyFromUserNoCheck((char *)to, (char *)from, size);
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}
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