testing/mmap.c

   1
   2 #include <stdio.h>
   3 #include <comedilib.h>
   4 #include <fcntl.h>
   5 #include <unistd.h>
   6 #include <sys/ioctl.h>
   7 #include <errno.h>
   8 #include <getopt.h>
   9 #include <ctype.h>
  10 #include <math.h>
  11 #include <sys/time.h>
  12 #include <string.h>
  13 #include <sys/mman.h>
  14 #include <signal.h>
  15 #include <setjmp.h>
  16 #include <stdlib.h>
  17
  18 #include "comedi_test.h"
  19
  20 /* XXX this should come from elsewhere */
  21 #define PAGE_SIZE 4096
  22
  23 #define N_SAMPLES 10000
  24
  25 #define BUFSZ N_SAMPLES*sizeof(sampl_t)
  26
  27 #define MAPLEN 20480
  28
  29 jmp_buf jump_env;
  30
  31 void segv_handler(int num)
  32 {
  33         longjmp(jump_env,1);
  34 }
  35
  36 int test_segfault(void *memptr)
  37 {
  38         volatile char tmp;
  39         int ret;
  40
  41         ret=setjmp(jump_env);
  42         if(!ret) tmp = *((char *)(memptr));
  43         return ret;
  44 }
  45
  46 void setup_segfaulter(void)
  47 {
  48         struct sigaction act;
  49
  50         memset(&act,0,sizeof(act));
  51         act.sa_handler=&segv_handler;
  52         sigaction(SIGSEGV,&act,NULL);
  53 }
  54
  55 int test_mmap(void)
  56 {
  57         comedi_cmd cmd;
  58         unsigned char *buf;
  59         unsigned int chanlist[1];
  60         int go;
  61         int fails;
  62         int total=0;
  63         int ret;
  64         void *b;
  65         unsigned char *adr;
  66         unsigned char *map;
  67         unsigned int flags;
  68         int i;
  69
  70         flags = comedi_get_subdevice_flags(device,subdevice);
  71
  72         if(!(flags&SDF_CMD) || flags&SDF_WRITEABLE){
  73                 printf("not applicable\n");
  74                 return 0;
  75         }
  76
  77         if(comedi_get_cmd_generic_timed(device,subdevice,&cmd,1)<0){
  78                 printf("E: comedi_get_cmd_generic_timed failed\n");
  79                 return 0;
  80         }
  81
  82         setup_segfaulter();
  83
  84         buf=malloc(BUFSZ);
  85
  86         map=mmap(NULL,MAPLEN,PROT_READ,MAP_SHARED,comedi_fileno(device),0);
  87         if(!map){
  88                 printf("E: mmap() failed\n");
  89                 return 0;
  90         }
  91
  92         /* test readability */
  93         for(adr=map;adr<map+MAPLEN;adr+=PAGE_SIZE){
  94                 ret=test_segfault(adr);
  95                 if(ret){
  96                         printf("E: %p failed\n",adr);
  97                 }else{
  98                         printf("%p ok\n",adr);
  99                 }
 100         }
 101
 102         if(realtime)cmd.flags |= TRIG_RT;
 103
 104         cmd.chanlist = chanlist;
 105         cmd.scan_end_arg = 1;
 106         cmd.stop_arg = N_SAMPLES;
 107         cmd.chanlist_len = 1;
 108         chanlist[0] = CR_PACK(0,0,0);
 109
 110         comedi_command(device,&cmd);
 111
 112         go=1;
 113         b=buf;
 114         while(go){
 115                 ret = read(comedi_fileno(device),b,BUFSZ);
 116                 if(ret<0){
 117                         if(errno==EAGAIN){
 118                                 usleep(10000);
 119                         }else{
 120                                 go = 0;
 121                                 perror("read");
 122                         }
 123                 }else if(ret==0){
 124                         go = 0;
 125                 }else{
 126                         total += ret;
 127                         b += ret;
 128                         if(verbose) printf("read %d %d\n",ret,total);
 129                 }
 130         }
 131
 132         fails = 0;
 133         for(i=0;i<total;i++){
 134                 if(buf[i]!=map[i]){
 135                         if(fails==0)printf("E: mmap compare failed\n");
 136                         printf("offset %d (read=%02x mmap=%02x)\n",i,
 137                                 buf[i], map[i]);
 138                         go = 0;
 139                         fails++;
 140                         if(fails>10)break;
 141                 }
 142         }
 143         if(fails==0) printf("compare ok\n");
 144
 145         munmap(map,MAPLEN);
 146
 147         /* test if area is really unmapped */
 148         for(adr=map;adr<map+MAPLEN;adr+=PAGE_SIZE){
 149                 ret=test_segfault(adr);
 150                 if(ret){
 151                         printf("%p segfaulted (ok)\n",adr);
 152                 }else{
 153                         printf("E: %p still mapped\n",adr);
 154                 }
 155         }
 156
 157         free(buf);
 158
 159         return 0;
 160 }
 161