IBM AIX Continuous Availability Features - IBM Redbooks

}
*(page+10)=10;
if (mode>0){
/*
* Remove KKEY_VMM from current keyset. After this operation current keysey=
* {KKEYSET_KERNEXT}
*/
if ((rc=kkeyset_remove_key(myset, KKEY_VMM, KA_RW))!=0){
printf("kkeyset_remove_key() failed\n");
return -1;
}
if ((rc=kkeyset_to_hkeyset(myset, &hwset))!=0){
printf("kkeyset_to_hkeyset() failed: rc=%lx\n",rc);
return -1;
}
/*
* Set current keyset= {KKEYSET_KERNEXT} using the Protection Gate to current
* kernel code path
*/
oldhwset1=hkeyset_replace(hwset);
printf("hardware keyset w/o KKEY_VMM =%lx\n",hwset);
/*
* Try accessing the private heap using the current keyset={KKEYSET_KERNEXT}.
* As the heap is protected by {KKEY_VMM} so this should
* result in a DSI or system crash (as there is no default exception handler
* defined for storage key exception- EXCEPT_SKEY
*/
*(page+10)=10;
printf("never reaches here\n");
}
/*
* Restore the hardware keyset to the value before module entry
*/
hkeyset_restore(hwset1);
/*
* Free the space occupied by data structures for kernel keyset
*/
xmfree(page, my_heap);
heap_destroy (my_heap,0);
kkeyset_delete(myset);
return 0;
The export file for kernel extension is shown in Example 3-23.
Example 3-23 Export file for kernel extension:kkey_set.exp
#!/unix
kkey_test syscall64
Sample code myprog.c is shown in Example 3-24.
Example 3-24 User program for accessing kernel extension: myprog.c
main(int argc, char** argv)
{
int param=0;
Chapter 3. AIX advanced continuous availability tools and features 93