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52 lines
1.3 KiB
ArmAsm
52 lines
1.3 KiB
ArmAsm
/*
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* COPYRIGHT: See COPYING in the top level directory
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* PROJECT: ReactOS system libraries
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* PURPOSE: Implementation of _chkstk and _alloca_probe
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* PROGRAMMERS Richard Henderson <rth@redhat.com>
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* Kai Tietz <kai.tietz@onevision.com>
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* Timo Kreuzer (timo.kreuzer@reactos.org)
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*/
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/* INCLUDES ******************************************************************/
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#include <asm.inc>
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#define PAGE_SIZE 4096
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/* CODE **********************************************************************/
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.code64
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PUBLIC ___chkstk_ms
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//cfi_startproc()
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___chkstk_ms:
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push rcx /* save temps */
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//cfi_push(%rcx)
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push rax
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//cfi_push(%rax)
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cmp rax, PAGE_SIZE /* > 4k ?*/
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lea rcx, [rsp + 24] /* point past return addr */
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jb l_LessThanAPage
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l_MoreThanAPage:
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sub rcx, PAGE_SIZE /* yes, move pointer down 4k */
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or byte ptr [rcx], 0 /* probe there */
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sub rax, PAGE_SIZE /* decrement count */
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cmp rax, PAGE_SIZE
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ja l_MoreThanAPage /* and do it again */
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l_LessThanAPage:
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sub rcx, rax
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or byte ptr [rcx], 0 /* less than 4k, just peek here */
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pop rax
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//cfi_pop(%rax)
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pop rcx
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//cfi_pop(%rcx)
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ret
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//cfi_endproc()
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END
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/* EOF */
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