Driver core fixes for 5.9-rc5

Here are some small driver core and debugfs fixes for 5.9-rc5
 
 Included in here are:
 	- firmware loader memory leak fix
 	- firmware loader testing fixes for non-EFI systems
 	- device link locking fixes found by lockdep
 	- kobject_del() bugfix that has been affecting some callers
 	- debugfs minor fix
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are some small driver core and debugfs fixes for 5.9-rc5

  Included in here are:

   - firmware loader memory leak fix

   - firmware loader testing fixes for non-EFI systems

   - device link locking fixes found by lockdep

   - kobject_del() bugfix that has been affecting some callers

   - debugfs minor fix

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  test_firmware: Test platform fw loading on non-EFI systems
  PM: <linux/device.h>: fix @em_pd kernel-doc warning
  kobject: Drop unneeded conditional in __kobject_del()
  driver core: Fix device_pm_lock() locking for device links
  MAINTAINERS: Add the security document to SECURITY CONTACT
  driver code: print symbolic error code
  debugfs: Fix module state check condition
  kobject: Restore old behaviour of kobject_del(NULL)
  firmware_loader: fix memory leak for paged buffer

MAINTAINERS

@@ -15577,6 +15577,7 @@ F:	include/uapi/linux/sed*
 SECURITY CONTACT
 M:	Security Officers <security@kernel.org>
 S:	Supported
+F:	Documentation/admin-guide/security-bugs.rst
 
 SECURITY SUBSYSTEM
 M:	James Morris <jmorris@namei.org>

drivers/base/core.c

@@ -807,9 +807,7 @@ static void device_link_put_kref(struct device_link *link)
 void device_link_del(struct device_link *link)
 {
 	device_links_write_lock();
-	device_pm_lock();
 	device_link_put_kref(link);
-	device_pm_unlock();
 	device_links_write_unlock();
 }
 EXPORT_SYMBOL_GPL(device_link_del);
@@ -830,7 +828,6 @@ void device_link_remove(void *consumer, struct device *supplier)
 		return;
 
 	device_links_write_lock();
-	device_pm_lock();
 
 	list_for_each_entry(link, &supplier->links.consumers, s_node) {
 		if (link->consumer == consumer) {
@@ -839,7 +836,6 @@ void device_link_remove(void *consumer, struct device *supplier)
 		}
 	}
 
-	device_pm_unlock();
 	device_links_write_unlock();
 }
 EXPORT_SYMBOL_GPL(device_link_remove);
@@ -4237,10 +4233,10 @@ int dev_err_probe(const struct device *dev, int err, const char *fmt, ...)
 	vaf.va = &args;
 
 	if (err != -EPROBE_DEFER) {
-		dev_err(dev, "error %d: %pV", err, &vaf);
+		dev_err(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
 	} else {
 		device_set_deferred_probe_reason(dev, &vaf);
-		dev_dbg(dev, "error %d: %pV", err, &vaf);
+		dev_dbg(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
 	}
 
 	va_end(args);

drivers/base/firmware_loader/firmware.h

@@ -142,10 +142,12 @@ int assign_fw(struct firmware *fw, struct device *device, u32 opt_flags);
 void fw_free_paged_buf(struct fw_priv *fw_priv);
 int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
 int fw_map_paged_buf(struct fw_priv *fw_priv);
+bool fw_is_paged_buf(struct fw_priv *fw_priv);
 #else
 static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
 static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
 static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
+static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
 #endif
 
 #endif /* __FIRMWARE_LOADER_H */

drivers/base/firmware_loader/main.c

@@ -252,9 +252,11 @@ static void __free_fw_priv(struct kref *ref)
 	list_del(&fw_priv->list);
 	spin_unlock(&fwc->lock);
 
-	fw_free_paged_buf(fw_priv); /* free leftover pages */
-	if (!fw_priv->allocated_size)
+	if (fw_is_paged_buf(fw_priv))
+		fw_free_paged_buf(fw_priv);
+	else if (!fw_priv->allocated_size)
 		vfree(fw_priv->data);
+
 	kfree_const(fw_priv->fw_name);
 	kfree(fw_priv);
 }
@@ -268,6 +270,11 @@ static void free_fw_priv(struct fw_priv *fw_priv)
 }
 
 #ifdef CONFIG_FW_LOADER_PAGED_BUF
+bool fw_is_paged_buf(struct fw_priv *fw_priv)
+{
+	return fw_priv->is_paged_buf;
+}
+
 void fw_free_paged_buf(struct fw_priv *fw_priv)
 {
 	int i;
@@ -275,6 +282,8 @@ void fw_free_paged_buf(struct fw_priv *fw_priv)
 	if (!fw_priv->pages)
 		return;
 
+	vunmap(fw_priv->data);
+
 	for (i = 0; i < fw_priv->nr_pages; i++)
 		__free_page(fw_priv->pages[i]);
 	kvfree(fw_priv->pages);
@@ -328,10 +337,6 @@ int fw_map_paged_buf(struct fw_priv *fw_priv)
 	if (!fw_priv->data)
 		return -ENOMEM;
 
-	/* page table is no longer needed after mapping, let's free */
-	kvfree(fw_priv->pages);
-	fw_priv->pages = NULL;
-
 	return 0;
 }
 #endif

drivers/firmware/efi/embedded-firmware.c

@@ -16,9 +16,9 @@
 
 /* Exported for use by lib/test_firmware.c only */
 LIST_HEAD(efi_embedded_fw_list);
-EXPORT_SYMBOL_GPL(efi_embedded_fw_list);
-
-static bool checked_for_fw;
+EXPORT_SYMBOL_NS_GPL(efi_embedded_fw_list, TEST_FIRMWARE);
+bool efi_embedded_fw_checked;
+EXPORT_SYMBOL_NS_GPL(efi_embedded_fw_checked, TEST_FIRMWARE);
 
 static const struct dmi_system_id * const embedded_fw_table[] = {
 #ifdef CONFIG_TOUCHSCREEN_DMI
@@ -116,14 +116,14 @@ void __init efi_check_for_embedded_firmwares(void)
 		}
 	}
 
-	checked_for_fw = true;
+	efi_embedded_fw_checked = true;
 }
 
 int efi_get_embedded_fw(const char *name, const u8 **data, size_t *size)
 {
 	struct efi_embedded_fw *iter, *fw = NULL;
 
-	if (!checked_for_fw) {
+	if (!efi_embedded_fw_checked) {
 		pr_warn("Warning %s called while we did not check for embedded fw\n",
 			__func__);
 		return -ENOENT;

fs/debugfs/file.c

@@ -177,7 +177,7 @@ static int open_proxy_open(struct inode *inode, struct file *filp)
 		goto out;
 
 	if (!fops_get(real_fops)) {
-#ifdef MODULE
+#ifdef CONFIG_MODULES
 		if (real_fops->owner &&
 		    real_fops->owner->state == MODULE_STATE_GOING)
 			goto out;
@@ -312,7 +312,7 @@ static int full_proxy_open(struct inode *inode, struct file *filp)
 		goto out;
 
 	if (!fops_get(real_fops)) {
-#ifdef MODULE
+#ifdef CONFIG_MODULES
 		if (real_fops->owner &&
 		    real_fops->owner->state == MODULE_STATE_GOING)
 			goto out;

include/linux/efi_embedded_fw.h

@@ -8,8 +8,8 @@
 #define EFI_EMBEDDED_FW_PREFIX_LEN		8
 
 /*
- * This struct and efi_embedded_fw_list are private to the efi-embedded fw
- * implementation they are in this header for use by lib/test_firmware.c only!
+ * This struct is private to the efi-embedded fw implementation.
+ * They are in this header for use by lib/test_firmware.c only!
  */
 struct efi_embedded_fw {
 	struct list_head list;
@@ -18,8 +18,6 @@ struct efi_embedded_fw {
 	size_t length;
 };
 
-extern struct list_head efi_embedded_fw_list;
-
 /**
  * struct efi_embedded_fw_desc - This struct is used by the EFI embedded-fw
  *                               code to search for embedded firmwares.

lib/kobject.c

@@ -604,9 +604,6 @@ static void __kobject_del(struct kobject *kobj)
 	struct kernfs_node *sd;
 	const struct kobj_type *ktype;
 
-	if (!kobj)
-		return;
-
 	sd = kobj->sd;
 	ktype = get_ktype(kobj);
 
@@ -637,8 +634,12 @@ static void __kobject_del(struct kobject *kobj)
  */
 void kobject_del(struct kobject *kobj)
 {
-	struct kobject *parent = kobj->parent;
+	struct kobject *parent;
 
+	if (!kobj)
+		return;
+
+	parent = kobj->parent;
 	__kobject_del(kobj);
 	kobject_put(parent);
 }

lib/test_firmware.c

@@ -26,6 +26,8 @@
 #include <linux/vmalloc.h>
 #include <linux/efi_embedded_fw.h>
 
+MODULE_IMPORT_NS(TEST_FIRMWARE);
+
 #define TEST_FIRMWARE_NAME	"test-firmware.bin"
 #define TEST_FIRMWARE_NUM_REQS	4
 #define TEST_FIRMWARE_BUF_SIZE	SZ_1K
@@ -489,6 +491,9 @@ out:
 static DEVICE_ATTR_WO(trigger_request);
 
 #ifdef CONFIG_EFI_EMBEDDED_FIRMWARE
+extern struct list_head efi_embedded_fw_list;
+extern bool efi_embedded_fw_checked;
+
 static ssize_t trigger_request_platform_store(struct device *dev,
 					      struct device_attribute *attr,
 					      const char *buf, size_t count)
@@ -501,6 +506,7 @@ static ssize_t trigger_request_platform_store(struct device *dev,
 	};
 	struct efi_embedded_fw efi_embedded_fw;
 	const struct firmware *firmware = NULL;
+	bool saved_efi_embedded_fw_checked;
 	char *name;
 	int rc;
 
@@ -513,6 +519,8 @@ static ssize_t trigger_request_platform_store(struct device *dev,
 	efi_embedded_fw.data = (void *)test_data;
 	efi_embedded_fw.length = sizeof(test_data);
 	list_add(&efi_embedded_fw.list, &efi_embedded_fw_list);
+	saved_efi_embedded_fw_checked = efi_embedded_fw_checked;
+	efi_embedded_fw_checked = true;
 
 	pr_info("loading '%s'\n", name);
 	rc = firmware_request_platform(&firmware, name, dev);
@@ -530,6 +538,7 @@ static ssize_t trigger_request_platform_store(struct device *dev,
 	rc = count;
 
 out:
+	efi_embedded_fw_checked = saved_efi_embedded_fw_checked;
 	release_firmware(firmware);
 	list_del(&efi_embedded_fw.list);
 	kfree(name);