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978 | jermar | 1 | /* |
2 | * Copyright (C) 2006 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 | |||
29 | #include <libc.h> |
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30 | #include <unistd.h> |
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31 | |||
1033 | jermar | 32 | /** mmap syscall |
33 | * |
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34 | * @param address Virtual address where to place new address space area. |
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35 | * @param size Size of the area. |
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36 | * @param flags Flags describing type of the area. |
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37 | * |
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38 | * @return address on success, (void *) -1 otherwise. |
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39 | */ |
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40 | void *mmap(void *address, size_t size, int flags) |
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978 | jermar | 41 | { |
1033 | jermar | 42 | return (void *) __SYSCALL3(SYS_MMAP, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags); |
43 | } |
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44 | |||
45 | /** mremap syscall |
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46 | * |
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47 | * @param address Virtual address pointing into already existing address space area. |
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48 | * @param size New requested size of the area. |
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49 | * @param flags Currently unused. |
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50 | * |
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51 | * @return address on success, (void *) -1 otherwise. |
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52 | */ |
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53 | void *mremap(void *address, size_t size, int flags) |
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54 | { |
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978 | jermar | 55 | return (void *) __SYSCALL3(SYS_MREMAP, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags); |
56 | } |
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985 | palkovsky | 57 | |
58 | static size_t heapsize = 0; |
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59 | /* Start of heap linker symbol */ |
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60 | extern char _heap; |
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61 | |||
62 | /** Sbrk emulation |
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63 | * |
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64 | * @param size New area that should be allocated or negative, |
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65 | if it should be shrinked |
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66 | * @return Pointer to newly allocated area |
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67 | */ |
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68 | void *sbrk(ssize_t incr) |
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69 | { |
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70 | void *res; |
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71 | /* Check for invalid values */ |
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72 | if (incr < 0 && -incr > heapsize) |
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73 | return NULL; |
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74 | /* Check for too large value */ |
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75 | if (incr > 0 && incr+heapsize < heapsize) |
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76 | return NULL; |
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77 | /* Check for too small values */ |
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78 | if (incr < 0 && incr+heapsize > heapsize) |
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79 | return NULL; |
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80 | |||
81 | res = mremap(&_heap, heapsize + incr,0); |
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82 | if (!res) |
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83 | return NULL; |
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999 | palkovsky | 84 | |
85 | /* Compute start of new area */ |
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86 | res = (void *)&_heap + heapsize; |
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87 | |||
985 | palkovsky | 88 | heapsize += incr; |
999 | palkovsky | 89 | |
985 | palkovsky | 90 | return res; |
91 | } |