lio_listio Problem

[Andreas Jaeger <aj at suse dot de>]

Kevin send me the appended test program (which I slightly modified).

It segfaults in:
Program received signal SIGSEGV, Segmentation fault.
0x40021423 in lio_listio (mode=1, list=0x8049960, nent=2, sig=0x0)
    at lio_listio.c:144
144     lio_listio.c: No such file or directory.



The problem seems to be that sig is dereferenced.  Unix98 specifies:

     If the mode argument is LIO_NOWAIT, the function returns
     immediately, and asynchronous notification occurs, according to the
     sig argument, when all the I/O operations complete. If sig is NULL,
     then no asynchronous notification occurs. If sig is not NULL,
     asynchronous notification occurs as specified in Signal Generation
     and Delivery when all the requests in list have completed.


How should this be fixed properly?

Andreas

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <signal.h>
#include <stdio.h>
#include <errno.h>
#include <sys/utsname.h>
#include <stdlib.h>
#include <string.h>

#include <aio.h>


#define FILENAME "async.log"
#define ACCESS_MODE "O_RDWR | O_CREAT"
#define NUM_OF_AIOCBS 2 

#define SIG_LISTIO_DONE (SIGRTMAX-9)


/*aiocb_t  async0, async1;*/
struct aiocb async_ctrl_blk[NUM_OF_AIOCBS];
char    *out_data[NUM_OF_AIOCBS];
int      counter;
int      buf_switch  = 0;

main()
{

   for(counter=0; counter<NUM_OF_AIOCBS; counter++)
   {
      out_data[counter] = (char*)malloc(sizeof(char)+2);
      sprintf(out_data[counter], "%1.1d\n", counter);
      printf("%s", out_data[counter]);
   }
   
   for(counter=0; counter<NUM_OF_AIOCBS; counter++)
   {
      async_ctrl_blk[counter] = (struct aiocb*)malloc(sizeof(struct aiocb));
      async_ctrl_blk[counter].aio_fildes = open(FILENAME,O_RDWR | O_APPEND | O_CREAT, 0666);
      async_ctrl_blk[counter].aio_offset = 0;
      async_ctrl_blk[counter].aio_lio_opcode = LIO_WRITE;
      async_ctrl_blk[counter].aio_buf = out_data[counter];
      async_ctrl_blk[counter].aio_nbytes = sizeof(char)+2;
   }

 
   if (lio_listio(LIO_NOWAIT, &async_ctrl_blk, NUM_OF_AIOCBS, NULL) < 0 )
      perror("lio_listio");

   aio_suspend(async_ctrl_blk, NUM_OF_AIOCBS, NULL);

}

-- 
 Andreas Jaeger
  SuSE Labs aj@suse.de
   private aj@arthur.inka.de