IB/hfi: Properly set permissions for user device files

Some of the device files are required to be user accessible for PSM while
most should remain accessible only by root.

Add a parameter to hfi1_cdev_init which controls if the user should have access
to this device which places it in a different class with the appropriate
devnode callback.

In addition set the devnode call back for the existing class to be a bit more
explicit for those permissions.

Finally remove the unnecessary null check before class_destroy

Tested-by: Donald Dutile <ddutile@redhat.com>
Signed-off-by: Haralanov, Mitko (mitko.haralanov@intel.com)
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

4 files changed, 59 insertions, 12 deletions

diff --git a/drivers/staging/rdma/hfi1/device.c b/drivers/staging/rdma/hfi1/device.c
index 07c87a87775f..bc26a5392712 100644
--- a/drivers/staging/rdma/hfi1/device.c
+++ b/drivers/staging/rdma/hfi1/device.c
@@ -57,11 +57,13 @@
 #include "device.h"
 
 static struct class *class;
+static struct class *user_class;
 static dev_t hfi1_dev;
 
 int hfi1_cdev_init(int minor, const char *name,
                    const struct file_operations *fops,
-                   struct cdev *cdev, struct device **devp)
+                   struct cdev *cdev, struct device **devp,
+                   bool user_accessible)
 {
         const dev_t dev = MKDEV(MAJOR(hfi1_dev), minor);
         struct device *device = NULL;
@@ -78,7 +80,11 @@ int hfi1_cdev_init(int minor, const char *name,
                 goto done;
         }
 
-        device = device_create(class, NULL, dev, NULL, "%s", name);
+        if (user_accessible)
+                device = device_create(user_class, NULL, dev, NULL, "%s", name);
+        else
+                device = device_create(class, NULL, dev, NULL, "%s", name);
+
         if (!IS_ERR(device))
                 goto done;
         ret = PTR_ERR(device);
@@ -110,6 +116,26 @@ const char *class_name(void)
         return hfi1_class_name;
 }
 
+static char *hfi1_devnode(struct device *dev, umode_t *mode)
+{
+        if (mode)
+                *mode = 0600;
+        return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
+}
+
+static const char *hfi1_class_name_user = "hfi1_user";
+const char *class_name_user(void)
+{
+        return hfi1_class_name_user;
+}
+
+static char *hfi1_user_devnode(struct device *dev, umode_t *mode)
+{
+        if (mode)
+                *mode = 0666;
+        return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
+}
+
 int __init dev_init(void)
 {
         int ret;
@@ -125,7 +151,22 @@ int __init dev_init(void)
                 ret = PTR_ERR(class);
                 pr_err("Could not create device class (err %d)\n", -ret);
                 unregister_chrdev_region(hfi1_dev, HFI1_NMINORS);
+                goto done;
         }
+        class->devnode = hfi1_devnode;
+
+        user_class = class_create(THIS_MODULE, class_name_user());
+        if (IS_ERR(user_class)) {
+                ret = PTR_ERR(user_class);
+                pr_err("Could not create device class for user accessible files (err %d)\n",
+                       -ret);
+                class_destroy(class);
+                class = NULL;
+                user_class = NULL;
+                unregister_chrdev_region(hfi1_dev, HFI1_NMINORS);
+                goto done;
+        }
+        user_class->devnode = hfi1_user_devnode;
 
 done:
         return ret;
@@ -133,10 +174,11 @@ done:
 
 void dev_cleanup(void)
 {
-        if (class) {
-                class_destroy(class);
-                class = NULL;
-        }
+        class_destroy(class);
+        class = NULL;
+
+        class_destroy(user_class);
+        user_class = NULL;
 
         unregister_chrdev_region(hfi1_dev, HFI1_NMINORS);
 }
diff --git a/drivers/staging/rdma/hfi1/device.h b/drivers/staging/rdma/hfi1/device.h
index 98caecd3d807..2850ff739d81 100644
--- a/drivers/staging/rdma/hfi1/device.h
+++ b/drivers/staging/rdma/hfi1/device.h
@@ -52,7 +52,8 @@
 
 int hfi1_cdev_init(int minor, const char *name,
                    const struct file_operations *fops,
-                   struct cdev *cdev, struct device **devp);
+                   struct cdev *cdev, struct device **devp,
+                   bool user_accessible);
 void hfi1_cdev_cleanup(struct cdev *cdev, struct device **devp);
 const char *class_name(void);
 int __init dev_init(void);
diff --git a/drivers/staging/rdma/hfi1/diag.c b/drivers/staging/rdma/hfi1/diag.c
index ce01deea834c..3e8d5ac4c626 100644
--- a/drivers/staging/rdma/hfi1/diag.c
+++ b/drivers/staging/rdma/hfi1/diag.c
@@ -292,7 +292,7 @@ int hfi1_diag_add(struct hfi1_devdata *dd)
         if (atomic_inc_return(&diagpkt_count) == 1) {
                 ret = hfi1_cdev_init(HFI1_DIAGPKT_MINOR, name,
                                      &diagpkt_file_ops, &diagpkt_cdev,
-                                     &diagpkt_device);
+                                     &diagpkt_device, false);
         }
 
         return ret;
@@ -592,7 +592,8 @@ static int hfi1_snoop_add(struct hfi1_devdata *dd, const char *name)
 
         ret = hfi1_cdev_init(HFI1_SNOOP_CAPTURE_BASE + dd->unit, name,
                              &snoop_file_ops,
-                             &dd->hfi1_snoop.cdev, &dd->hfi1_snoop.class_dev);
+                             &dd->hfi1_snoop.cdev, &dd->hfi1_snoop.class_dev,
+                             false);
 
         if (ret) {
                 dd_dev_err(dd, "Couldn't create %s device: %d", name, ret);
diff --git a/drivers/staging/rdma/hfi1/file_ops.c b/drivers/staging/rdma/hfi1/file_ops.c
index 2c43ca5a379b..72d38500d8ce 100644
--- a/drivers/staging/rdma/hfi1/file_ops.c
+++ b/drivers/staging/rdma/hfi1/file_ops.c
@@ -2090,14 +2090,16 @@ static int user_add(struct hfi1_devdata *dd)
 
         if (atomic_inc_return(&user_count) == 1) {
                 ret = hfi1_cdev_init(0, class_name(), &hfi1_file_ops,
-                                     &wildcard_cdev, &wildcard_device);
+                                     &wildcard_cdev, &wildcard_device,
+                                     true);
                 if (ret)
                         goto done;
         }
 
         snprintf(name, sizeof(name), "%s_%d", class_name(), dd->unit);
         ret = hfi1_cdev_init(dd->unit + 1, name, &hfi1_file_ops,
-                             &dd->user_cdev, &dd->user_device);
+                             &dd->user_cdev, &dd->user_device,
+                             true);
         if (ret)
                 goto done;
 
@@ -2105,7 +2107,8 @@ static int user_add(struct hfi1_devdata *dd)
                 snprintf(name, sizeof(name),
                          "%s_ui%d", class_name(), dd->unit);
                 ret = hfi1_cdev_init(dd->unit + UI_OFFSET, name, &ui_file_ops,
-                                     &dd->ui_cdev, &dd->ui_device);
+                                     &dd->ui_cdev, &dd->ui_device,
+                                     false);
                 if (ret)
                         goto done;
         }