view src/hermes/x86_main.asm @ 1199:2d6dc7de1145

From: Mike Frysinger <vapier@gentoo.org> To: sdl@libsdl.org Date: Sun, 11 Dec 2005 22:57:37 -0500 Subject: [SDL] exec stack in libsdl update i posted back in September a patch to remove executable stacks: http://www.devolution.com/pipermail/sdl/2005-September/070626.html later in November, a similar patch was merged it seems: http://www.libsdl.org/cgi/cvsweb.cgi/SDL12/src/hermes/mmx_main.asm however, this lacks the additional output format checks that i posted in my patch ... this isnt a problem if the hermes asm code is only ever used to produce ELF objects, but if this is not true, then the additional checks in my original patch will need to be merged -mike
author Ryan C. Gordon <icculus@icculus.org>
date Mon, 12 Dec 2005 09:13:12 +0000
parents da33b7e6d181
children 3202d727bb4b
line wrap: on
line source

;
; x86 format converters for HERMES
; Some routines Copyright (c) 1998 Christian Nentwich (brn@eleet.mcb.at)
; This source code is licensed under the GNU LGPL
; 
; Please refer to the file COPYING.LIB contained in the distribution for
; licensing conditions		
;
; Most routines are (c) Glenn Fiedler (ptc@gaffer.org), used with permission
; 

BITS 32

GLOBAL _ConvertX86
GLOBAL _x86return
	
GLOBAL _Hermes_X86_CPU

SECTION .data
	
cpu_flags dd 0
	
		
SECTION .text
		
;; _ConvertX86:	 
;; [ESP+8] ConverterInfo*
;; --------------------------------------------------------------------------
;; ConverterInfo (ebp+..)
;;   0:	void *s_pixels
;;   4:	int s_width
;;   8:	int s_height
;;  12:	int s_add
;;  16:	void *d_pixels
;;  20:	int d_width
;;  24:	int d_height
;;  28:	int d_add
;;  32:	void (*converter_function)() 
;;  36: int32 *lookup
	
_ConvertX86:
	push ebp
	mov ebp,esp

; Save the registers used by the blitters, necessary for optimized code
	pusha

	mov eax,[ebp+8]

        cmp dword [eax+4],BYTE 0
	je endconvert
	
	mov ebp,eax
	
	mov esi,[ebp+0]
	mov edi,[ebp+16]
	
y_loop:	
	mov ecx,[ebp+4]

	jmp [ebp+32]

_x86return:	
	add esi,[ebp+12]
	add edi,[ebp+28]
	
	dec dword  [ebp+8]
	jnz y_loop

; Restore the registers used by the blitters, necessary for optimized code
	popa
	
	pop ebp

endconvert:	
	ret		



;; Hermes_X86_CPU returns the CPUID flags in eax
	
_Hermes_X86_CPU:
	pushfd
	pop eax
	
	mov ecx,eax
	
	xor eax,040000h
	push eax
	
	popfd
	pushfd

	pop eax
	xor eax,ecx
	jz .L1			; Processor is 386

	push ecx
	popfd

	mov eax,ecx
	xor eax,200000h

	push eax
	popfd
	pushfd

	pop eax
	xor eax,ecx
	je .L1
	
	pusha
	
	mov eax,1
	cpuid

	mov [cpu_flags],edx

	popa

	mov eax,[cpu_flags]

.L1:	
	ret

%ifidn __OUTPUT_FORMAT__,elf
section .note.GNU-stack noalloc noexec nowrite progbits
%endif