| 1 | /* i386-specific implementation of profiling support. |
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| 2 | Copyright (C) 1997-2022 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #include <sysdep.h> |
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| 20 | |
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| 21 | /* We need a special version of the `mcount' function since for ix86 it |
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| 22 | must not clobber any register. This has several reasons: |
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| 23 | - there is a bug in gcc as of version 2.7.2.2 which prohibits the |
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| 24 | use of profiling together with nested functions |
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| 25 | - the ELF `fixup' function uses GCC's regparm feature |
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| 26 | - some (future) systems might want to pass parameters in registers. */ |
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| 27 | |
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| 28 | .globl C_SYMBOL_NAME(_mcount) |
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| 29 | .type C_SYMBOL_NAME(_mcount), @function |
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| 30 | .align ALIGNARG(4) |
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| 31 | C_LABEL(_mcount) |
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| 32 | _CET_ENDBR |
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| 33 | /* Save the caller-clobbered registers. */ |
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| 34 | pushl %eax |
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| 35 | pushl %ecx |
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| 36 | pushl %edx |
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| 37 | |
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| 38 | movl 12(%esp), %edx |
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| 39 | movl 4(%ebp), %eax |
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| 40 | |
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| 41 | /* No need to access the PLT or GOT, __mcount_internal is an |
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| 42 | internal function and we can make a relative call. */ |
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| 43 | call C_SYMBOL_NAME(__mcount_internal) |
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| 44 | |
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| 45 | /* Pop the saved registers. Please note that `mcount' has no |
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| 46 | return value. */ |
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| 47 | popl %edx |
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| 48 | popl %ecx |
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| 49 | popl %eax |
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| 50 | ret |
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| 51 | ASM_SIZE_DIRECTIVE(C_SYMBOL_NAME(_mcount)) |
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| 52 | |
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| 53 | #undef mcount |
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| 54 | weak_alias (_mcount, mcount) |
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| 55 | |
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| 56 | /* Same as above, but doesn't require a frame pointer */ |
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| 57 | .globl C_SYMBOL_NAME(__fentry__) |
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| 58 | .type C_SYMBOL_NAME(__fentry__), @function |
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| 59 | .align ALIGNARG(4) |
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| 60 | C_LABEL(__fentry__) |
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| 61 | _CET_ENDBR |
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| 62 | /* Save the caller-clobbered registers. */ |
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| 63 | pushl %eax |
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| 64 | pushl %ecx |
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| 65 | pushl %edx |
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| 66 | |
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| 67 | movl 12(%esp), %edx |
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| 68 | movl 16(%esp), %eax |
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| 69 | |
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| 70 | /* No need to access the PLT or GOT, __mcount_internal is an |
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| 71 | internal function and we can make a relative call. */ |
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| 72 | call C_SYMBOL_NAME(__mcount_internal) |
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| 73 | |
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| 74 | /* Pop the saved registers. Please note that `__fentry__' has no |
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| 75 | return value. */ |
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| 76 | popl %edx |
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| 77 | popl %ecx |
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| 78 | popl %eax |
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| 79 | ret |
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| 80 | ASM_SIZE_DIRECTIVE(C_SYMBOL_NAME(__fentry__)) |
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| 81 | |
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