RE: script compilation fails at 'Pass 4'

[Mehul Choube <Mehul_Choube at symantec dot com>]

On Thu, 6 Dec 2012, Frank Ch. Eigler wrote:

>
> Mehul_Choube wrote:
>
>> http://pastebin.com/vyKHBGd0
>
> sockname() can't work like that.  Systemtap embedded-C code runs
> within the kernel, and can't call userspace glibc functions or
> system calls like that.
>
> Try instead:
>
> ########################################################################
> function print_fd(fd) {
>         task = task_current()
>         sock = task_file_handle_socket(task,fd)
> 	 if (sock) {
>            fam = socket_family(sock)
>            if (fam == %{ AF_INET %}) {
> 	       printf("%s[%d] fd %d: %s\n", execname(), tid(), fd,
>                      socket_ipv4_sockname(sock))
>               return 0
>            } /* other cases as per pfiles.stp */
>         }
> }
>
> probe syscall.connect.return {
>      if ($return >= 0) print_fd($return)
> }
>
>
> /* the rest verbatim from pfiles.stp */
>
> %{
> #include <linux/file.h>
> #include <net/sock.h>
> #include <linux/un.h>
> #include <linux/tcp.h>
> #include <linux/in.h>
> %}
>
> function task_file_handle_socket:long (task:long, fd:long) %{ /* pure */
>        struct task_struct *p = (struct task_struct *)((long)STAP_ARG_task);
> 	struct files_struct *files;
>        struct file *filp;
>        struct dentry *dentry;
>        struct inode *inode;
>
>        rcu_read_lock();
>        if ((files = kread(&p->files)) &&
>            (filp = fcheck_files(files, STAP_ARG_fd)) &&
>            (dentry = kread(&filp->f_dentry)) &&
>            (inode = kread(&filp->f_dentry->d_inode))) {
>                if (S_ISSOCK(kread(&inode->i_mode)))
>                        STAP_RETVALUE = (long)SOCKET_I(inode);
>        }
>
>        CATCH_DEREF_FAULT();
>        rcu_read_unlock();
> %}
>
> function socket_family:long (sock:long) %{ /* pure */
> 	struct socket *sock = (struct socket *)((long)STAP_ARG_sock);
>        const struct proto_ops *ops = kread(&sock->ops);
>        STAP_RETVALUE = (long)kread(&ops->family);
>        CATCH_DEREF_FAULT();
> %}
>
> function socket_ipv4_sockname:string (sock:long) %{ /* pure */
>        struct socket *sock = (struct socket *)((long)STAP_ARG_sock);
>        const struct proto_ops *ops = kread(&sock->ops);
>        struct sockaddr_in in_addr;
>        __be32 addr, port;
>        int err, len;
>
> 	err = ops->getname (sock, (struct sockaddr*)(&in_addr), &len, 0);
>        if (!err) {
>                addr = in_addr.sin_addr.s_addr;
>                port = htons(in_addr.sin_port);
> 		snprintf(STAP_RETVALUE, MAXSTRINGLEN,
>                        "        sockname: AF_INET " NIPQUAD_FMT "  port: %d",
> 	                NIPQUAD(addr), port);
>        }
>        CATCH_DEREF_FAULT();
> %}
>
>

Now it fails with:
error: 'STAP_ARG_sock' undeclared (first use in this function)

please check: http://pastebin.com/wvZFu02g



Thanks,
Mehul