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Date: Fri, 30 Apr 2010 09:01:53 -0700
From: Greg KH <greg@...ah.com>
To: David Woodhouse <dwmw2@...radead.org>
Cc: linux-kernel@...r.kernel.org, Kay Sievers <kay.sievers@...y.org>,
Greg Kroah-Hartman <gregkh@...e.de>,
Johannes Berg <johannes@...solutions.net>,
Ming Lei <tom.leiming@...il.com>,
Catalin Marinas <catalin.marinas@....com>,
Tomas Winkler <tomas.winkler@...el.com>
Subject: Re: firmware_class: fix memory leak - free allocated pages
On Thu, Apr 29, 2010 at 09:26:17PM +0300, David Woodhouse wrote:
>
> From: David Woodhouse <dwmw2@...radead.org>
>
> 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.
But it does create a ton of compiler warnings due the const * change. I
had to fix up the patch to get the firmware.c file to build cleanly, but
that then causes a bunch of warnings all over the tree.
So can someone please fix the patch up properly so it doesn't have these
problems and resend it to me?
thanks,
greg k-h
>
> Cc: Johannes Berg <johannes@...solutions.net>
> Cc: Greg Kroah-Hartman <gregkh@...e.de>
> Cc: Ming Lei <tom.leiming@...il.com>
> Cc: Catalin Marinas <catalin.marinas@....com>
> Cc: Kay Sievers <kay.sievers@...y.org>
> Signed-off-by: David Woodhouse <dwmw2@...radead.org>
> Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>
>
> ---
> drivers/base/firmware_class.c | 30 +++++++++++++++++++++++-------
> include/linux/firmware.h | 5 +++--
> 2 files changed, 26 insertions(+), 9 deletions(-)
>
> --- a/drivers/base/firmware_class.c
> +++ b/drivers/base/firmware_class.c
> @@ -130,6 +130,20 @@ static ssize_t firmware_loading_show(str
> return sprintf(buf, "%d\n", loading);
> }
>
> +static void firmware_free_data(struct firmware *fw)
> +{
> + int i;
> + vunmap(fw->data);
> + fw->data = NULL;
> + if (fw->pages) {
> + for (i = 0; i < PFN_UP(fw->size); i++)
> + __free_page(fw->pages[i]);
> + kfree(fw->pages);
> + }
> + fw->pages = NULL;
> + fw->size = 0;
> +}
> +
> /* Some architectures don't have PAGE_KERNEL_RO */
> #ifndef PAGE_KERNEL_RO
> #define PAGE_KERNEL_RO PAGE_KERNEL
> @@ -162,21 +176,20 @@ static ssize_t firmware_loading_store(st
> mutex_unlock(&fw_lock);
> break;
> }
> - vfree(fw_priv->fw->data);
> - fw_priv->fw->data = NULL;
> + firmware_free_data(fw_priv->fw);
> + /* 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 +197,10 @@ static ssize_t firmware_loading_store(st
> 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);
> @@ -568,7 +584,7 @@ request_firmware(const struct firmware *
> * @fw: firmware resource to release
> **/
> void
> -release_firmware(const struct firmware *fw)
> +release_firmware(struct firmware *fw)
> {
> struct builtin_fw *builtin;
>
> @@ -578,7 +594,7 @@ release_firmware(const struct firmware *
> if (fw->data == builtin->data)
> goto free_fw;
> }
> - vfree(fw->data);
> + firmware_free_data(fw);
> free_fw:
> kfree(fw);
> }
> --- 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;
> @@ -42,7 +43,7 @@ int request_firmware_nowait(
> const char *name, struct device *device, gfp_t gfp, void *context,
> void (*cont)(const struct firmware *fw, void *context));
>
> -void release_firmware(const struct firmware *fw);
> +void release_firmware(struct firmware *fw);
> #else
> static inline int request_firmware(const struct firmware **fw,
> const char *name,
> @@ -58,7 +59,7 @@ static inline int request_firmware_nowai
> return -EINVAL;
> }
>
> -static inline void release_firmware(const struct firmware *fw)
> +static inline void release_firmware(struct firmware *fw)
> {
> }
> #endif
--
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