[PATCH 02/38] firmware_class: fix memory leak - free allocated pages

From: Greg Kroah-Hartman
Date: Fri May 21 2010 - 13:01:04 EST


From: David Woodhouse <David.Woodhouse@xxxxxxxxx>

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@xxxxxxxxxxxxxxxx>
Cc: Ming Lei <tom.leiming@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Singed-off-by: Kay Sievers <kay.sievers@xxxxxxxx>
Signed-off-by: David Woodhouse <David.Woodhouse@xxxxxxxxx>
Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/base/firmware_class.c | 26 ++++++++++++++++++++------
include/linux/firmware.h | 1 +
2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 985da11..4c70b91 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);
}
diff --git a/include/linux/firmware.h b/include/linux/firmware.h
index 043811f..53d1e6c 100644
--- a/include/linux/firmware.h
+++ b/include/linux/firmware.h
@@ -12,6 +12,7 @@
struct firmware {
size_t size;
const u8 *data;
+ struct page **pages;
};

struct device;
--
1.7.0.3

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