IBM AIX Continuous Availability Features - IBM Redbooks

}
}
perror("parent:shmget()");
return (1);
}
if ( (data=shmat(id,(void *)0, 0)) == (char*) (-1) ){
perror("parent:shmat()");
return (1);
}
if (rc=ukey_protect(data,one_page,pkey)){
perror("parent:ukey_protect(pkey)");
exit(1);
}
oldset=ukeyset_activate(pkeyset,UKA_ADD_KEYS);
if (oldset==UKSET_INVALID){
printf("parent:ukeyset_activate() failed");
exit (1);
}
sleep(2);
printf("parent:READ1 =[%s]\n",data);
strcpy(data+strlen(data),"ABCD");
printf("parent:WRITE1=[ABCD]\n");
sleep(2);
if (shmdt(data)==-1){
perror("parent:shmdt()");
return (1);
}
if (shmctl(id,IPC_RMID,0)){
perror("parent:shmctl()");
return (1);
}
return (0);
We compiled the program:
# cc -g -o ukey1 ukey1.c
We gave the child process write (no-read) access on the shared memory segment, and
executed it as shown in Example 3-32.
Example 3-32 Executing program with write access to shared memory
# ./ukey1 write
parent:pagesize=4096
child:data=0x30000000
parent:READ1 =[]
parent:WRITE1=[ABCD]
# ls core
core
# dbx ukey1 core
Type 'help' for help.
[using memory image in core]
reading symbolic information ...
Segmentation fault in strlen at 0xd010da00
0xd010da00 (strlen) 89030000 lbz r8,0x0(r3)
(dbx) where
Chapter 3. AIX advanced continuous availability tools and features 105