| 1 | .\" Copyright (c) 2006-2008 Joseph Koshy. All rights reserved. |
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| 2 | .\" |
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| 3 | .\" Redistribution and use in source and binary forms, with or without |
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| 4 | .\" modification, are permitted provided that the following conditions |
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| 5 | .\" are met: |
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| 6 | .\" 1. Redistributions of source code must retain the above copyright |
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| 7 | .\" notice, this list of conditions and the following disclaimer. |
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| 8 | .\" 2. Redistributions in binary form must reproduce the above copyright |
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| 9 | .\" notice, this list of conditions and the following disclaimer in the |
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| 10 | .\" documentation and/or other materials provided with the distribution. |
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| 11 | .\" |
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| 12 | .\" This software is provided by Joseph Koshy ``as is'' and |
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| 13 | .\" any express or implied warranties, including, but not limited to, the |
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| 14 | .\" implied warranties of merchantability and fitness for a particular purpose |
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| 15 | .\" are disclaimed. in no event shall Joseph Koshy be liable |
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| 16 | .\" for any direct, indirect, incidental, special, exemplary, or consequential |
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| 17 | .\" damages (including, but not limited to, procurement of substitute goods |
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| 18 | .\" or services; loss of use, data, or profits; or business interruption) |
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| 19 | .\" however caused and on any theory of liability, whether in contract, strict |
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| 20 | .\" liability, or tort (including negligence or otherwise) arising in any way |
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| 21 | .\" out of the use of this software, even if advised of the possibility of |
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| 22 | .\" such damage. |
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| 23 | .\" |
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| 24 | .\" $Id: elf_getscn.3 189 2008-07-20 10:38:08Z jkoshy $ |
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| 25 | .\" |
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| 26 | .Dd October 22, 2007 |
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| 27 | .Os |
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| 28 | .Dt ELF_GETSCN 3 |
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| 29 | .Sh NAME |
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| 30 | .Nm elf_getscn , |
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| 31 | .Nm elf_ndxscn , |
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| 32 | .Nm elf_newscn , |
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| 33 | .Nm elf_nextscn |
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| 34 | .Nd get/allocate section information for an ELF object |
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| 35 | .Sh LIBRARY |
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| 36 | .Lb libelf |
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| 37 | .Sh SYNOPSIS |
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| 38 | .In libelf.h |
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| 39 | .Ft "Elf_Scn *" |
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| 40 | .Fn elf_getscn "Elf *elf" "size_t index" |
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| 41 | .Ft size_t |
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| 42 | .Fn elf_ndxscn "Elf_Scn *scn" |
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| 43 | .Ft "Elf_Scn *" |
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| 44 | .Fn elf_newscn "Elf *elf" |
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| 45 | .Ft "Elf_Scn *" |
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| 46 | .Fn elf_nextscn "Elf *elf" "Elf_Scn *scn" |
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| 47 | .Sh DESCRIPTION |
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| 48 | These functions are used to iterate through the sections associated |
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| 49 | with an ELF descriptor. |
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| 50 | .Pp |
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| 51 | Function |
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| 52 | .Fn elf_getscn |
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| 53 | will return a section descriptor for the section at index |
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| 54 | .Ar index |
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| 55 | in the object denoted by ELF descriptor |
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| 56 | .Ar elf . |
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| 57 | An error will be signalled if the specified section does not |
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| 58 | exist. |
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| 59 | .Pp |
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| 60 | Function |
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| 61 | .Fn elf_ndxscn |
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| 62 | returns the section table index associated with section descriptor |
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| 63 | .Ar scn . |
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| 64 | .Pp |
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| 65 | Function |
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| 66 | .Fn elf_newscn |
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| 67 | creates a new section and appends it to the list of sections |
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| 68 | associated with descriptor |
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| 69 | .Ar elf . |
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| 70 | The library will automatically increment the |
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| 71 | .Va e_shnum |
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| 72 | field of the ELF header associated with descriptor |
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| 73 | .Ar elf , |
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| 74 | and will set the |
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| 75 | .Dv ELF_F_DIRTY |
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| 76 | flag on the returned section descriptor. |
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| 77 | For ELF descriptors opened for writing, the ELF library will |
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| 78 | automatically create an empty section at index zero |
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| 79 | .Dv ( SHN_UNDEF ) |
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| 80 | on the first call to |
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| 81 | .Fn elf_newscn . |
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| 82 | .Pp |
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| 83 | Function |
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| 84 | .Fn elf_nextscn |
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| 85 | takes a section descriptor |
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| 86 | .Ar scn |
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| 87 | and returns a pointer to the section descriptor at the next higher |
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| 88 | index. |
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| 89 | Argument |
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| 90 | .Ar scn |
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| 91 | is allowed to be NULL, in which case this function will return a |
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| 92 | pointer to the section descriptor at index 1. |
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| 93 | If no further sections are present, function |
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| 94 | .Fn elf_nextscn |
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| 95 | will return a NULL pointer. |
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| 96 | .Sh RETURN VALUES |
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| 97 | Functions |
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| 98 | .Fn elf_getscn , |
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| 99 | .Fn elf_newscn |
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| 100 | and |
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| 101 | .Fn elf_nextscn |
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| 102 | return a valid pointer to a section descriptor if successful, or |
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| 103 | NULL if an error occurs. |
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| 104 | .Pp |
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| 105 | Function |
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| 106 | .Fn elf_ndxscn |
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| 107 | returns a valid section table index if successful, or |
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| 108 | .Dv SHN_UNDEF |
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| 109 | if an error occurs. |
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| 110 | .Sh ERRORS |
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| 111 | These functions may fail with the following errors: |
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| 112 | .Bl -tag -width "[ELF_E_RESOURCE]" |
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| 113 | .It Bq Er ELF_E_ARGUMENT |
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| 114 | Arguments |
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| 115 | .Ar elf |
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| 116 | or |
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| 117 | .Ar scn |
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| 118 | were NULL. |
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| 119 | .It Bq Er ELF_E_ARGUMENT |
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| 120 | Argument |
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| 121 | .Ar index |
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| 122 | exceeded the current number of sections in the ELF object. |
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| 123 | .It Bq Er ELF_E_ARGUMENT |
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| 124 | Argument |
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| 125 | .Ar elf |
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| 126 | was not a descriptor for an ELF file. |
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| 127 | .It Bq Er ELF_E_ARGUMENT |
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| 128 | Section descriptor |
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| 129 | .Ar scn |
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| 130 | was not associated with ELF descriptor |
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| 131 | .Ar elf . |
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| 132 | .It Bq Er ELF_E_CLASS |
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| 133 | Descriptor |
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| 134 | .Ar elf |
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| 135 | was of an unknown ELF class. |
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| 136 | .It Bq Er ELF_E_SECTION |
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| 137 | Argument |
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| 138 | .Ar elf |
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| 139 | specified extended section numbering in the ELF header with the section header at |
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| 140 | index |
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| 141 | .Dv SHN_UNDEF |
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| 142 | not being of type |
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| 143 | .Dv SHT_NULL . |
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| 144 | .El |
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| 145 | .Sh SEE ALSO |
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| 146 | .Xr elf 3 , |
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| 147 | .Xr elf_flagdata 3 , |
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| 148 | .Xr elf_flagscn 3 , |
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| 149 | .Xr elf_getdata 3 , |
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| 150 | .Xr elf_getshdr 3 , |
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| 151 | .Xr gelf 3 |
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