Mercurial > sdl-ios-xcode
annotate src/thread/SDL_thread.c @ 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 | b8d311d90021 |
| children | 173c063d4f55 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
|
769
b8d311d90021
Updated copyright information for 2004 (Happy New Year!)
Sam Lantinga <slouken@libsdl.org>
parents:
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|
3 Copyright (C) 1997-2004 Sam Lantinga |
| 0 | 4 |
| 5 This library is free software; you can redistribute it and/or | |
| 6 modify it under the terms of the GNU Library General Public | |
| 7 License as published by the Free Software Foundation; either | |
| 8 version 2 of the License, or (at your option) any later version. | |
| 9 | |
| 10 This library is distributed in the hope that it will be useful, | |
| 11 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 Library General Public License for more details. | |
| 14 | |
| 15 You should have received a copy of the GNU Library General Public | |
| 16 License along with this library; if not, write to the Free | |
| 17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 18 | |
| 19 Sam Lantinga | |
|
252
e8157fcb3114
Updated the source with the correct e-mail address
Sam Lantinga <slouken@libsdl.org>
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20 slouken@libsdl.org |
| 0 | 21 */ |
| 22 | |
| 23 #ifdef SAVE_RCSID | |
| 24 static char rcsid = | |
| 25 "@(#) $Id$"; | |
| 26 #endif | |
| 27 | |
| 28 /* System independent thread management routines for SDL */ | |
| 29 | |
| 30 #include <stdio.h> | |
| 31 #include <stdlib.h> | |
| 32 #include <string.h> | |
| 33 | |
| 34 #include "SDL_error.h" | |
| 35 #include "SDL_mutex.h" | |
| 36 #include "SDL_thread.h" | |
| 37 #include "SDL_thread_c.h" | |
| 38 #include "SDL_systhread.h" | |
| 39 | |
| 40 #define ARRAY_CHUNKSIZE 32 | |
| 41 /* The array of threads currently active in the application | |
| 42 (except the main thread) | |
| 43 The manipulation of an array here is safer than using a linked list. | |
| 44 */ | |
| 45 static int SDL_maxthreads = 0; | |
| 46 static int SDL_numthreads = 0; | |
| 47 static SDL_Thread **SDL_Threads = NULL; | |
| 48 static SDL_mutex *thread_lock = NULL; | |
| 49 int _creating_thread_lock = 0; | |
| 50 | |
| 51 int SDL_ThreadsInit(void) | |
| 52 { | |
| 53 int retval; | |
| 54 | |
| 55 retval = 0; | |
| 56 /* Set the thread lock creation flag so that we can reuse an | |
| 57 existing lock on the system - since this mutex never gets | |
| 58 destroyed (see SDL_ThreadsQuit()), we want to reuse it. | |
| 59 */ | |
| 60 _creating_thread_lock = 1; | |
| 61 thread_lock = SDL_CreateMutex(); | |
| 62 _creating_thread_lock = 0; | |
| 63 if ( thread_lock == NULL ) { | |
| 64 retval = -1; | |
| 65 } | |
| 66 return(retval); | |
| 67 } | |
| 68 | |
| 69 /* This should never be called... | |
| 70 If this is called by SDL_Quit(), we don't know whether or not we should | |
| 71 clean up threads here. If any threads are still running after this call, | |
| 72 they will no longer have access to any per-thread data. | |
| 73 */ | |
| 74 void SDL_ThreadsQuit() | |
| 75 { | |
| 76 SDL_mutex *mutex; | |
| 77 | |
| 78 mutex = thread_lock; | |
| 79 thread_lock = NULL; | |
| 80 if ( mutex != NULL ) { | |
| 81 SDL_DestroyMutex(mutex); | |
| 82 } | |
| 83 } | |
| 84 | |
| 85 /* Routines for manipulating the thread list */ | |
| 86 static void SDL_AddThread(SDL_Thread *thread) | |
| 87 { | |
| 88 SDL_Thread **threads; | |
| 89 | |
| 90 /* WARNING: | |
| 91 If the very first threads are created simultaneously, then | |
| 92 there could be a race condition causing memory corruption. | |
| 93 In practice, this isn't a problem because by definition there | |
| 94 is only one thread running the first time this is called. | |
| 95 */ | |
| 96 if ( thread_lock == NULL ) { | |
| 97 if ( SDL_ThreadsInit() < 0 ) { | |
| 98 return; | |
| 99 } | |
| 100 } | |
| 101 SDL_mutexP(thread_lock); | |
| 102 | |
| 103 /* Expand the list of threads, if necessary */ | |
| 104 #ifdef DEBUG_THREADS | |
| 105 printf("Adding thread (%d already - %d max)\n", | |
| 106 SDL_numthreads, SDL_maxthreads); | |
| 107 #endif | |
| 108 if ( SDL_numthreads == SDL_maxthreads ) { | |
| 109 threads=(SDL_Thread **)malloc((SDL_maxthreads+ARRAY_CHUNKSIZE)* | |
| 110 (sizeof *threads)); | |
| 111 if ( threads == NULL ) { | |
| 112 SDL_OutOfMemory(); | |
| 113 goto done; | |
| 114 } | |
| 115 memcpy(threads, SDL_Threads, SDL_numthreads*(sizeof *threads)); | |
| 116 SDL_maxthreads += ARRAY_CHUNKSIZE; | |
| 117 if ( SDL_Threads ) { | |
| 118 free(SDL_Threads); | |
| 119 } | |
| 120 SDL_Threads = threads; | |
| 121 } | |
| 122 SDL_Threads[SDL_numthreads++] = thread; | |
| 123 done: | |
| 124 SDL_mutexV(thread_lock); | |
| 125 } | |
| 126 | |
| 127 static void SDL_DelThread(SDL_Thread *thread) | |
| 128 { | |
| 129 int i; | |
| 130 | |
| 131 if ( thread_lock ) { | |
| 132 SDL_mutexP(thread_lock); | |
| 133 for ( i=0; i<SDL_numthreads; ++i ) { | |
| 134 if ( thread == SDL_Threads[i] ) { | |
| 135 break; | |
| 136 } | |
| 137 } | |
| 138 if ( i < SDL_numthreads ) { | |
|
340
b9f1ce709960
Fixed a minor memory leak in the SDL thread subsystem
Sam Lantinga <slouken@libsdl.org>
parents:
329
diff
changeset
|
139 if ( --SDL_numthreads > 0 ) { |
|
b9f1ce709960
Fixed a minor memory leak in the SDL thread subsystem
Sam Lantinga <slouken@libsdl.org>
parents:
329
diff
changeset
|
140 while ( i < SDL_numthreads ) { |
|
b9f1ce709960
Fixed a minor memory leak in the SDL thread subsystem
Sam Lantinga <slouken@libsdl.org>
parents:
329
diff
changeset
|
141 SDL_Threads[i] = SDL_Threads[i+1]; |
|
b9f1ce709960
Fixed a minor memory leak in the SDL thread subsystem
Sam Lantinga <slouken@libsdl.org>
parents:
329
diff
changeset
|
142 ++i; |
|
b9f1ce709960
Fixed a minor memory leak in the SDL thread subsystem
Sam Lantinga <slouken@libsdl.org>
parents:
329
diff
changeset
|
143 } |
|
b9f1ce709960
Fixed a minor memory leak in the SDL thread subsystem
Sam Lantinga <slouken@libsdl.org>
parents:
329
diff
changeset
|
144 } else { |
|
b9f1ce709960
Fixed a minor memory leak in the SDL thread subsystem
Sam Lantinga <slouken@libsdl.org>
parents:
329
diff
changeset
|
145 SDL_maxthreads = 0; |
|
b9f1ce709960
Fixed a minor memory leak in the SDL thread subsystem
Sam Lantinga <slouken@libsdl.org>
parents:
329
diff
changeset
|
146 free(SDL_Threads); |
|
b9f1ce709960
Fixed a minor memory leak in the SDL thread subsystem
Sam Lantinga <slouken@libsdl.org>
parents:
329
diff
changeset
|
147 SDL_Threads = NULL; |
| 0 | 148 } |
| 149 #ifdef DEBUG_THREADS | |
| 150 printf("Deleting thread (%d left - %d max)\n", | |
| 151 SDL_numthreads, SDL_maxthreads); | |
| 152 #endif | |
| 153 } | |
| 154 SDL_mutexV(thread_lock); | |
| 155 } | |
| 156 } | |
| 157 | |
| 158 /* The default (non-thread-safe) global error variable */ | |
| 159 static SDL_error SDL_global_error; | |
| 160 | |
| 161 /* Routine to get the thread-specific error variable */ | |
| 162 SDL_error *SDL_GetErrBuf(void) | |
| 163 { | |
| 164 SDL_error *errbuf; | |
| 165 | |
| 166 errbuf = &SDL_global_error; | |
| 167 if ( SDL_Threads ) { | |
| 168 int i; | |
| 169 Uint32 this_thread; | |
| 170 | |
| 171 this_thread = SDL_ThreadID(); | |
| 172 SDL_mutexP(thread_lock); | |
| 173 for ( i=0; i<SDL_numthreads; ++i ) { | |
| 174 if ( this_thread == SDL_Threads[i]->threadid ) { | |
| 175 errbuf = &SDL_Threads[i]->errbuf; | |
| 176 break; | |
| 177 } | |
| 178 } | |
| 179 SDL_mutexV(thread_lock); | |
| 180 } | |
| 181 return(errbuf); | |
| 182 } | |
| 183 | |
| 184 | |
| 185 /* Arguments and callback to setup and run the user thread function */ | |
| 186 typedef struct { | |
| 187 int (*func)(void *); | |
| 188 void *data; | |
| 189 SDL_Thread *info; | |
| 190 SDL_sem *wait; | |
| 191 } thread_args; | |
| 192 | |
| 193 void SDL_RunThread(void *data) | |
| 194 { | |
| 195 thread_args *args; | |
| 196 int (*userfunc)(void *); | |
| 197 void *userdata; | |
| 198 int *statusloc; | |
| 199 | |
| 200 /* Perform any system-dependent setup | |
| 201 - this function cannot fail, and cannot use SDL_SetError() | |
| 202 */ | |
| 203 SDL_SYS_SetupThread(); | |
| 204 | |
| 205 /* Get the thread id */ | |
| 206 args = (thread_args *)data; | |
| 207 args->info->threadid = SDL_ThreadID(); | |
| 208 | |
| 209 /* Figure out what function to run */ | |
| 210 userfunc = args->func; | |
| 211 userdata = args->data; | |
| 212 statusloc = &args->info->status; | |
| 213 | |
| 214 /* Wake up the parent thread */ | |
| 215 SDL_SemPost(args->wait); | |
| 216 | |
| 217 /* Run the function */ | |
| 218 *statusloc = userfunc(userdata); | |
| 219 } | |
| 220 | |
| 221 SDL_Thread *SDL_CreateThread(int (*fn)(void *), void *data) | |
| 222 { | |
| 223 SDL_Thread *thread; | |
| 224 thread_args *args; | |
| 225 int ret; | |
| 226 | |
| 227 /* Allocate memory for the thread info structure */ | |
| 228 thread = (SDL_Thread *)malloc(sizeof(*thread)); | |
| 229 if ( thread == NULL ) { | |
| 230 SDL_OutOfMemory(); | |
| 231 return(NULL); | |
| 232 } | |
| 233 memset(thread, 0, (sizeof *thread)); | |
| 234 thread->status = -1; | |
| 235 | |
| 236 /* Set up the arguments for the thread */ | |
| 237 args = (thread_args *)malloc(sizeof(*args)); | |
| 238 if ( args == NULL ) { | |
| 239 SDL_OutOfMemory(); | |
| 240 free(thread); | |
| 241 return(NULL); | |
| 242 } | |
| 243 args->func = fn; | |
| 244 args->data = data; | |
| 245 args->info = thread; | |
| 246 args->wait = SDL_CreateSemaphore(0); | |
| 247 if ( args->wait == NULL ) { | |
| 248 free(thread); | |
| 249 free(args); | |
| 250 return(NULL); | |
| 251 } | |
| 252 | |
| 253 /* Add the thread to the list of available threads */ | |
| 254 SDL_AddThread(thread); | |
| 255 | |
| 256 /* Create the thread and go! */ | |
| 257 ret = SDL_SYS_CreateThread(thread, args); | |
| 258 if ( ret >= 0 ) { | |
| 259 /* Wait for the thread function to use arguments */ | |
| 260 SDL_SemWait(args->wait); | |
| 261 } else { | |
| 262 /* Oops, failed. Gotta free everything */ | |
| 263 SDL_DelThread(thread); | |
| 264 free(thread); | |
| 265 thread = NULL; | |
| 266 } | |
| 267 SDL_DestroySemaphore(args->wait); | |
| 268 free(args); | |
| 269 | |
| 270 /* Everything is running now */ | |
| 271 return(thread); | |
| 272 } | |
| 273 | |
| 274 void SDL_WaitThread(SDL_Thread *thread, int *status) | |
| 275 { | |
| 276 if ( thread ) { | |
| 277 SDL_SYS_WaitThread(thread); | |
| 278 if ( status ) { | |
| 279 *status = thread->status; | |
| 280 } | |
| 281 SDL_DelThread(thread); | |
| 282 free(thread); | |
| 283 } | |
| 284 } | |
| 285 | |
| 286 Uint32 SDL_GetThreadID(SDL_Thread *thread) | |
| 287 { | |
| 288 Uint32 id; | |
| 289 | |
| 290 if ( thread ) { | |
| 291 id = thread->threadid; | |
| 292 } else { | |
| 293 id = SDL_ThreadID(); | |
| 294 } | |
| 295 return(id); | |
| 296 } | |
| 297 | |
| 298 void SDL_KillThread(SDL_Thread *thread) | |
| 299 { | |
| 300 if ( thread ) { | |
| 301 SDL_SYS_KillThread(thread); | |
| 302 SDL_WaitThread(thread, NULL); | |
| 303 } | |
| 304 } | |
| 305 |