view src/video/riscos/SDL_riscosASM.s @ 1176:dd2a8deeb26d

Date: Mon, 17 Oct 2005 20:09:03 -0400 From: Mark Schreiber <mark7@alumni.cmu.edu> To: ryan@clutteredmind.org Subject: [PATCH]SDL mprotect() crash fix (I'm going to throw this patch your way at the suggestion of #SDL -- for some reason, I had some difficulty sending it to the main list last time, and I go bonkers subscribing to send each email or patch...) Currently, when I run SDL applications as non-root using SDL_VIDEODRIVER=dga, the fbdev fallback mprotect()s read/write the proper size of mmapped /dev/fb0 (7.5MB), but on framebuffer release mprotect()s read-only the range by the entire size of my video memory (128MB), which causes a segfault: #0 0x002a9a27 in ?? () from /lib/libc.so.6 #1 0x04a63eb6 in SDL_XDGAUnmapFramebuffer (screen=3D0) at XF86DGA2.c:978 #2 0x04a63efc in SDL_XDGACloseFramebuffer (dpy=3D0x9d3f008, screen=3D0) at XF86DGA2.c:268 #3 0x04a68b57 in DGA_Available () at SDL_dgavideo.c:98 #4 0x04a53677 in SDL_VideoInit (driver_name=3D0xbfb0bfc7 "dga", flags=3D0) at SDL_video.c:180 #5 0x04a2613f in SDL_InitSubSystem (flags=3D32) at SDL.c:74 #6 0x04a2617c in SDL_Init (flags=3D32) at SDL.c:166 #7 0x08049722 in main (argc=3D1, argv=3D0x0) at testwin.c:32 This is SDL 1.2.8 on Fedora Core 4, radeon driver for a Radeon 9250, xorg-x11-6.8.2-37. I've attached a one-line patch against SDL CVS that updates the size of the framebuffer at framebuffer map time so that the mprotect() on unmap will be the same size. I'm not sure if this is the best approach (i.e. one might want to retain the original value), but it does make my SDL applications work without segfaulting. -- Best of luck, Mark Schreiber
author Ryan C. Gordon <icculus@icculus.org>
date Sat, 19 Nov 2005 18:57:00 +0000
parents 7eeb3324d37d
children c9b51268668f
line wrap: on
line source

;
;    SDL - Simple DirectMedia Layer
;    Copyright (C) 1997-2004 Sam Lantinga
;
;    This library is free software; you can redistribute it and/or
;    modify it under the terms of the GNU Library General Public
;    License as published by the Free Software Foundation; either
;    version 2 of the License, or (at your option) any later version.
;
;    This library is distributed in the hope that it will be useful,
;    but WITHOUT ANY WARRANTY; without even the implied warranty of
;    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;    Library General Public License for more details.
;
;    You should have received a copy of the GNU Library General Public
;    License along with this library; if not, write to the Free
;    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
;
;    Sam Lantinga
;    slouken@devolution.com
;
; Assembler routines for RISC OS display
;

	AREA |C$$CODE|

	EXPORT |RISCOS_Put32|

; Display 32bpp to 32bpp, 1:1
;
; Code provided by Adrain Lees
;
; entry a1 -> destination
;       a2 =  dest width in pixels
;       a3 =  dest line length in bytes
;       a4 =  dest height in scanlines
;       arg5 -> source
;       arg6 =  byte offset from end of source line to start of next

Arg5    *       10*4
Arg6    *       Arg5+4

RISCOS_Put32    ROUT
                STMFD   sp!,{a2,v1-v6,sl,fp,lr}
                LDR     ip,[sp,#Arg5]
                MOV     lr,a1
                B       ucp64lp

00              ;tail strip of 1-15 pixels

                LDR     v1,[ip],#4
01              SUBS    a2,a2,#1
                STR     v1,[lr],#4
                LDRHI   v1,[ip],#4
                BHI     %01
                B       %02

ucp64end        ADDS    a2,a2,#16
                BNE     %00

02              SUBS    a4,a4,#1                ;height--
                LDRHI   v1,[sp,#Arg6]
                LDRHI   a2,[sp]                 ;reload width
                BLS     %03

                ;move to start of next scanline

                ADD     lr,a1,a3
                ADD     a1,a1,a3
                ADD     ip,ip,v1

ucp64lp         SUBS    a2,a2,#16
                BLO     ucp64end

                PLD     [ip,#64]

                LDR     v1,[ip],#4
                LDR     v2,[ip],#4
                LDR     v3,[ip],#4
                LDR     v4,[ip],#4
                LDR     v5,[ip],#4
                LDR     v6,[ip],#4
                LDR     sl,[ip],#4
                LDR     fp,[ip],#4
                STR     v1,[lr],#4
                STR     v2,[lr],#4
                STR     v3,[lr],#4
                STR     v4,[lr],#4
                STR     v5,[lr],#4
                STR     v6,[lr],#4
                STR     sl,[lr],#4
                STR     fp,[lr],#4

                PLD     [ip,#64]

                LDR     v1,[ip],#4
                LDR     v2,[ip],#4
                LDR     v3,[ip],#4
                LDR     v4,[ip],#4
                LDR     v5,[ip],#4
                LDR     v6,[ip],#4
                LDR     sl,[ip],#4
                LDR     fp,[ip],#4
                STR     v1,[lr],#4
                STR     v2,[lr],#4
                STR     v3,[lr],#4
                STR     v4,[lr],#4
                STR     v5,[lr],#4
                STR     v6,[lr],#4
                STR     sl,[lr],#4
                STR     fp,[lr],#4

                B       ucp64lp

03              LDMFD   sp!,{a2,v1-v6,sl,fp,pc}