Hello to all, i'm trying to develop a kernel module that accepts an ioctl with this structure :
Code:
typedef struct{
/* [INPUT] */
long process;
unsigned long address;
/* [OUTPUT] */ long mm_size;
}
mg_query_t;
where :
process : is the pid of a process .
address : is the address of a buffer on the stack of that process .
mm_size : *should* be the return value of the ioctl, indicating the size of that buffer, as an example (userspace test application):
Code:
char * abuffer[123];
mg_query_t query;
query.process = getpid();
query.address = abuffer;
if( ioctl( fd, IOCTL_MTABLE_BY_PID, &query ) < 0 ){
close(fd);
perror( "IOCTL_MTABLE_BY_PID" );
return -1;
}
printf( "SIZE : %d\n", query.mm_size );
This *should* give the output :
SIZE : 123
I'm using the struct task_struct in the kernel module, looping the mmap to find the vm area the address resides in and then to set
mm_size = vm_end - vm_start
But doing so i obtaing only the size of the vm page the buffer resides .
Any hints ?
Thanks in advantage .
