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,siginfo_t *si,void *x)
  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_sigaction=&segv_handler;
  52         act.sa_flags = SA_SIGINFO;
  53         sigaction(SIGSEGV,&act,NULL);
  54 }
  55
  56 int test_mmap(void)
  57 {
  58         comedi_cmd cmd;
  59         char *buf;
  60         unsigned int chanlist[1];
  61         int go;
  62         int total=0;
  63         int ret;
  64         void *b, *adr;
  65         sampl_t *map;
  66
  67         if(!(comedi_get_subdevice_flags(device,subdevice)&SDF_CMD)){
  68                 printf("not applicable\n");
  69                 return 0;
  70         }
  71
  72         if(comedi_get_cmd_generic_timed(device,subdevice,&cmd)<0){
  73                 printf("E: comedi_get_cmd_generic_timed failed\n");
  74                 return 0;
  75         }
  76
  77         setup_segfaulter();
  78
  79         buf=malloc(BUFSZ);
  80
  81         map=mmap(NULL,MAPLEN,PROT_READ,MAP_SHARED,comedi_fileno(device),0);
  82         if(!map){
  83                 printf("E: mmap() failed\n");
  84                 return 0;
  85         }
  86
  87         /* test readability */
  88         for(adr=map;adr<(void *)map+MAPLEN;adr+=PAGE_SIZE){
  89                 ret=test_segfault(adr);
  90                 if(ret){
  91                         printf("E: %p failed\n",adr);
  92                 }else{
  93                         printf("%p ok\n",adr);
  94                 }
  95         }
  96
  97         cmd.chanlist = chanlist;
  98         cmd.scan_end_arg = 1;
  99         cmd.stop_arg = N_SAMPLES;
 100         cmd.chanlist_len = 1;
 101         chanlist[0] = CR_PACK(0,0,0);
 102
 103         comedi_command(device,&cmd);
 104
 105         go=1;
 106         b=buf;
 107         while(go){
 108                 ret = read(comedi_fileno(device),b,BUFSZ);
 109                 if(ret<0){
 110                         if(errno==EAGAIN){
 111                                 usleep(10000);
 112                         }else{
 113                                 go = 0;
 114                                 perror("read");
 115                         }
 116                 }else if(ret==0){
 117                         go = 0;
 118                 }else{
 119                         total += ret;
 120                         b += ret;
 121                         printf("read %d %d\n",ret,total);
 122                 }
 123         }
 124         if(memcmp(buf,map,total)){
 125                 printf("E: mmap compare failed\n");
 126         }else{
 127                 printf("compare ok\n");
 128         }
 129         munmap(map,MAPLEN);
 130
 131         /* test if area is really unmapped */
 132         for(adr=map;adr<(void *)map+MAPLEN;adr+=PAGE_SIZE){
 133                 ret=test_segfault(adr);
 134                 if(ret){
 135                         printf("%p segfaulted (ok)\n",adr);
 136                 }else{
 137                         printf("E: %p still mapped\n",adr);
 138                 }
 139         }
 140
 141         free(buf);
 142
 143         return 0;
 144 }
 145