firmware_class: fix memory leak - free allocated pages

fix memory leak introduced by the patch 6e03a201bbe:
firmware: speed up request_firmware()

1. vfree won't release pages there were allocated explicitly and mapped
using vmap. The memory has to be vunmap-ed and the pages needs
to be freed explicitly

2. page array is moved into the 'struct
firmware' so that we can free it from release_firmware()
and not only in fw_dev_release()

The fix doesn't break the firmware load speed.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Singed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 20 insertions, 6 deletions

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 985da11174e..4c70b9148b2 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -130,6 +130,17 @@ static ssize_t firmware_loading_show(struct device *dev,
         return sprintf(buf, "%d\n", loading);
 }
 
+static void firmware_free_data(const struct firmware *fw)
+{
+        int i;
+        vunmap(fw->data);
+        if (fw->pages) {
+                for (i = 0; i < PFN_UP(fw->size); i++)
+                        __free_page(fw->pages[i]);
+                kfree(fw->pages);
+        }
+}
+
 /* Some architectures don't have PAGE_KERNEL_RO */
 #ifndef PAGE_KERNEL_RO
 #define PAGE_KERNEL_RO PAGE_KERNEL
@@ -162,21 +173,21 @@ static ssize_t firmware_loading_store(struct device *dev,
                         mutex_unlock(&fw_lock);
                         break;
                 }
-                vfree(fw_priv->fw->data);
-                fw_priv->fw->data = NULL;
+                firmware_free_data(fw_priv->fw);
+                memset(fw_priv->fw, 0, sizeof(struct firmware));
+                /* If the pages are not owned by 'struct firmware' */
                 for (i = 0; i < fw_priv->nr_pages; i++)
                         __free_page(fw_priv->pages[i]);
                 kfree(fw_priv->pages);
                 fw_priv->pages = NULL;
                 fw_priv->page_array_size = 0;
                 fw_priv->nr_pages = 0;
-                fw_priv->fw->size = 0;
                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
                 mutex_unlock(&fw_lock);
                 break;
         case 0:
                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
-                        vfree(fw_priv->fw->data);
+                        vunmap(fw_priv->fw->data);
                         fw_priv->fw->data = vmap(fw_priv->pages,
                                                  fw_priv->nr_pages,
                                                  0, PAGE_KERNEL_RO);
@@ -184,7 +195,10 @@ static ssize_t firmware_loading_store(struct device *dev,
                                 dev_err(dev, "%s: vmap() failed\n", __func__);
                                 goto err;
                         }
-                        /* Pages will be freed by vfree() */
+                        /* Pages are now owned by 'struct firmware' */
+                        fw_priv->fw->pages = fw_priv->pages;
+                        fw_priv->pages = NULL;
+
                         fw_priv->page_array_size = 0;
                         fw_priv->nr_pages = 0;
                         complete(&fw_priv->completion);
@@ -578,7 +592,7 @@ release_firmware(const struct firmware *fw)
                         if (fw->data == builtin->data)
                                 goto free_fw;
                 }
-                vfree(fw->data);
+                firmware_free_data(fw);
         free_fw:
                 kfree(fw);
         }