IB/ipath: Make ipath_portdata work with struct pid * not pid_t

The official reason is "with the presence of pid namespaces in the
kernel using pid_t-s inside one is no longer safe."

But the reason I fix this right now is the following:

About a month ago (when 2.6.25 was not yet released) there still was a
one last caller of a to-be-deprecated-soon function find_pid() - the
kill_proc() function, which in turn was only used by nfs callback
code.

During the last merge window, this last caller was finally eliminated
by some NFS patch(es) and I was about to finally kill this kill_proc()
and find_pid(), but found, that I was late and the kill_proc is now
called from the ipath driver since commit 58411d1c ("IB/ipath: Head of
Line blocking vs forward progress of user apps").

So here's a patch that fixes this code to use struct pid * and (!)
the kill_pid routine.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

3 files changed, 23 insertions, 18 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index ce7b7c34360e..258e66cf3546 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -2616,7 +2616,7 @@ int ipath_reset_device(int unit)
                                 ipath_dbg("unit %u port %d is in use "
                                           "(PID %u cmd %s), can't reset\n",
                                           unit, i,
-                                          dd->ipath_pd[i]->port_pid,
+                                          pid_nr(dd->ipath_pd[i]->port_pid),
                                           dd->ipath_pd[i]->port_comm);
                                 ret = -EBUSY;
                                 goto bail;
@@ -2654,19 +2654,21 @@ bail:
 static int ipath_signal_procs(struct ipath_devdata *dd, int sig)
 {
         int i, sub, any = 0;
-        pid_t pid;
+        struct pid *pid;
 
         if (!dd->ipath_pd)
                 return 0;
         for (i = 1; i < dd->ipath_cfgports; i++) {
-                if (!dd->ipath_pd[i] || !dd->ipath_pd[i]->port_cnt ||
-                    !dd->ipath_pd[i]->port_pid)
+                if (!dd->ipath_pd[i] || !dd->ipath_pd[i]->port_cnt)
                         continue;
                 pid = dd->ipath_pd[i]->port_pid;
+                if (!pid)
+                        continue;
+
                 dev_info(&dd->pcidev->dev, "context %d in use "
                           "(PID %u), sending signal %d\n",
-                          i, pid, sig);
-                kill_proc(pid, sig, 1);
+                          i, pid_nr(pid), sig);
+                kill_pid(pid, sig, 1);
                 any++;
                 for (sub = 0; sub < INFINIPATH_MAX_SUBPORT; sub++) {
                         pid = dd->ipath_pd[i]->port_subpid[sub];
@@ -2674,8 +2676,8 @@ static int ipath_signal_procs(struct ipath_devdata *dd, int sig)
                                 continue;
                         dev_info(&dd->pcidev->dev, "sub-context "
                                 "%d:%d in use (PID %u), sending "
-                                "signal %d\n", i, sub, pid, sig);
-                        kill_proc(pid, sig, 1);
+                                "signal %d\n", i, sub, pid_nr(pid), sig);
+                        kill_pid(pid, sig, 1);
                         any++;
                 }
         }
diff --git a/drivers/infiniband/hw/ipath/ipath_file_ops.c b/drivers/infiniband/hw/ipath/ipath_file_ops.c
index 3295177c937e..b472b15637f0 100644
--- a/drivers/infiniband/hw/ipath/ipath_file_ops.c
+++ b/drivers/infiniband/hw/ipath/ipath_file_ops.c
@@ -555,7 +555,7 @@ static int ipath_tid_free(struct ipath_portdata *pd, unsigned subport,
                         p = dd->ipath_pageshadow[porttid + tid];
                         dd->ipath_pageshadow[porttid + tid] = NULL;
                         ipath_cdbg(VERBOSE, "PID %u freeing TID %u\n",
-                                   pd->port_pid, tid);
+                                   pid_nr(pd->port_pid), tid);
                         dd->ipath_f_put_tid(dd, &tidbase[tid],
                                             RCVHQ_RCV_TYPE_EXPECTED,
                                             dd->ipath_tidinvalid);
@@ -1609,7 +1609,7 @@ static int try_alloc_port(struct ipath_devdata *dd, int port,
                            port);
                 pd->port_cnt = 1;
                 port_fp(fp) = pd;
-                pd->port_pid = current->pid;
+                pd->port_pid = get_pid(task_pid(current));
                 strncpy(pd->port_comm, current->comm, sizeof(pd->port_comm));
                 ipath_stats.sps_ports++;
                 ret = 0;
@@ -1793,14 +1793,15 @@ static int find_shared_port(struct file *fp,
                         }
                         port_fp(fp) = pd;
                         subport_fp(fp) = pd->port_cnt++;
-                        pd->port_subpid[subport_fp(fp)] = current->pid;
+                        pd->port_subpid[subport_fp(fp)] =
+                                get_pid(task_pid(current));
                         tidcursor_fp(fp) = 0;
                         pd->active_slaves |= 1 << subport_fp(fp);
                         ipath_cdbg(PROC,
                                    "%s[%u] %u sharing %s[%u] unit:port %u:%u\n",
                                    current->comm, current->pid,
                                    subport_fp(fp),
-                                   pd->port_comm, pd->port_pid,
+                                   pd->port_comm, pid_nr(pd->port_pid),
                                    dd->ipath_unit, pd->port_port);
                         ret = 1;
                         goto done;
@@ -2066,7 +2067,8 @@ static int ipath_close(struct inode *in, struct file *fp)
                  * the slave(s) don't wait for receive data forever.
                  */
                 pd->active_slaves &= ~(1 << fd->subport);
-                pd->port_subpid[fd->subport] = 0;
+                put_pid(pd->port_subpid[fd->subport]);
+                pd->port_subpid[fd->subport] = NULL;
                 mutex_unlock(&ipath_mutex);
                 goto bail;
         }
@@ -2074,7 +2076,7 @@ static int ipath_close(struct inode *in, struct file *fp)
 
         if (pd->port_hdrqfull) {
                 ipath_cdbg(PROC, "%s[%u] had %u rcvhdrqfull errors "
-                           "during run\n", pd->port_comm, pd->port_pid,
+                           "during run\n", pd->port_comm, pid_nr(pd->port_pid),
                            pd->port_hdrqfull);
                 pd->port_hdrqfull = 0;
         }
@@ -2134,11 +2136,12 @@ static int ipath_close(struct inode *in, struct file *fp)
                         unlock_expected_tids(pd);
                 ipath_stats.sps_ports--;
                 ipath_cdbg(PROC, "%s[%u] closed port %u:%u\n",
-                           pd->port_comm, pd->port_pid,
+                           pd->port_comm, pid_nr(pd->port_pid),
                            dd->ipath_unit, port);
         }
 
-        pd->port_pid = 0;
+        put_pid(pd->port_pid);
+        pd->port_pid = NULL;
         dd->ipath_pd[pd->port_port] = NULL; /* before releasing mutex */
         mutex_unlock(&ipath_mutex);
         ipath_free_pddata(dd, pd); /* after releasing the mutex */
diff --git a/drivers/infiniband/hw/ipath/ipath_kernel.h b/drivers/infiniband/hw/ipath/ipath_kernel.h
index 02b24a340599..20975875a8d1 100644
--- a/drivers/infiniband/hw/ipath/ipath_kernel.h
+++ b/drivers/infiniband/hw/ipath/ipath_kernel.h
@@ -159,8 +159,8 @@ struct ipath_portdata {
         /* saved total number of polled urgent packets for poll edge trigger */
         u32 port_urgent_poll;
         /* pid of process using this port */
-        pid_t port_pid;
-        pid_t port_subpid[INFINIPATH_MAX_SUBPORT];
+        struct pid *port_pid;
+        struct pid *port_subpid[INFINIPATH_MAX_SUBPORT];
         /* same size as task_struct .comm[] */
         char port_comm[16];
         /* pkeys set by this use of this port */