Re: [v2] ath6kl: Use vmalloc to allocate ar->fw for api1 method

From: Eric Dumazet
Date: Wed Dec 02 2015 - 08:20:39 EST


On Tue, 2015-12-01 at 22:18 -0600, Brent Taylor wrote:
> Since commit 8437754c8335 ("ath6kl: Use vmalloc instead of kmalloc for
> fw") ar->fw is expected to be pointing to memory allocated by vmalloc.
> If the api1 method (via ath6kl_fetch_fw_api1) is used to allocate memory
> for ar->fw, then kmemdup is used. This patch checks if the firmware being
> loaded is the 'fw' image, then use vmalloc, otherwise use kmalloc.
>
> Signed-off-by: Brent Taylor <motobud@xxxxxxxxx>
> ---
> v2: Fix commit message and code formatting (use tab instaed of spaces)
>
> drivers/net/wireless/ath/ath6kl/init.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/ath/ath6kl/init.c b/drivers/net/wireless/ath/ath6kl/init.c
> index 6ae0734..4f16bd8 100644
> --- a/drivers/net/wireless/ath/ath6kl/init.c
> +++ b/drivers/net/wireless/ath/ath6kl/init.c
> @@ -673,10 +673,15 @@ static int ath6kl_get_fw(struct ath6kl *ar, const char *filename,
> return ret;
>
> *fw_len = fw_entry->size;
> - *fw = kmemdup(fw_entry->data, fw_entry->size, GFP_KERNEL);
> + if (&ar->fw == fw)
> + *fw = vmalloc(fw_entry->size);
> + else
> + *fw = kmalloc(fw_entry->size, GFP_KERNEL);
>
> if (*fw == NULL)
> ret = -ENOMEM;
> + else
> + memcpy(*fw, fw_entry->data, fw_entry->size);
>
> release_firmware(fw_entry);
>

This looks very odd.

Why not using kvfree() in ath6kl_core_cleanup() ?

If you switch to vmalloc() here because the kmemdup() was potentially
failing, then the changelog should say it !

Using vmalloc() instead of kmalloc() should be driven by the allocation
size, not the legacy code doing the freeing.



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