1 | /*
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2 | * Copyright (c) 2005 Jakub Jermar
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3 | * All rights reserved.
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4 | *
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5 | * Redistribution and use in source and binary forms, with or without
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6 | * modification, are permitted provided that the following conditions
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7 | * are met:
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8 | *
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9 | * - Redistributions of source code must retain the above copyright
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10 | * notice, this list of conditions and the following disclaimer.
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11 | * - Redistributions in binary form must reproduce the above copyright
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12 | * notice, this list of conditions and the following disclaimer in the
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13 | * documentation and/or other materials provided with the distribution.
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14 | * - The name of the author may not be used to endorse or promote products
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15 | * derived from this software without specific prior written permission.
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16 | *
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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27 | */
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28 |
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29 | /** @addtogroup ia32
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30 | * @{
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31 | */
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32 | /** @file
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33 | */
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34 |
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35 | #include <userspace.h>
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36 | #include <arch/pm.h>
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37 | #include <arch/types.h>
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38 | #include <arch.h>
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39 | #include <proc/uarg.h>
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40 | #include <mm/as.h>
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41 |
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42 |
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43 | /** Enter userspace
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44 | *
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45 | * Change CPU protection level to 3, enter userspace.
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46 | *
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47 | */
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48 | void userspace(uspace_arg_t *kernel_uarg)
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49 | {
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50 | ipl_t ipl;
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51 |
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52 | ipl = interrupts_disable();
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53 |
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54 | asm volatile (
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55 | /*
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56 | * Clear nested task flag.
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57 | */
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58 | "pushfl\n"
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59 | "pop %%eax\n"
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60 | "and $0xffffbfff, %%eax\n"
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61 | "push %%eax\n"
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62 | "popfl\n"
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63 |
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64 | /* Set up GS register (TLS) */
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65 | "movl %6, %%gs\n"
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66 |
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67 | "pushl %0\n"
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68 | "pushl %1\n"
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69 | "pushl %2\n"
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70 | "pushl %3\n"
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71 | "pushl %4\n"
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72 | "movl %5, %%eax\n"
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73 | "iret\n"
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74 | :
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75 | : "i" (selector(UDATA_DES) | PL_USER), "r" (kernel_uarg->uspace_stack+THREAD_STACK_SIZE),
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76 | "r" (ipl), "i" (selector(UTEXT_DES) | PL_USER), "r" (kernel_uarg->uspace_entry),
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77 | "r" (kernel_uarg->uspace_uarg),
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78 | "r" (selector(TLS_DES))
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79 | : "eax");
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80 |
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81 | /* Unreachable */
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82 | for(;;)
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83 | ;
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84 | }
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85 |
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86 | /** @}
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87 | */
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