on Sat, 15 Jun 2013 11:08:47 +0300, Ming Lei <ming....@canonical.com>
wrote:
On Sat, Jun 15, 2013 at 2:30 PM, Guenter Roeck <li...@roeck-us.net>
wrote:
On Sat, Jun 15, 2013 at 10:32:14AM +0800, Ming Lei wrote:
On Sat, Jun 15, 2013 at 1:07 AM, nirinA raseliarison
<nirina.raseliari...@gmail.com> wrote:
> patch applied and no longer have the bug message when i
> reboot and wake up the ethernet controller.
I am wondering if Guenter's patch can fix the race really, but I'd
like to
see Guenter's explanation on his patch.
The race should be caused by below:
- request timeout triggered by internal timer
- user space aborts the requests before the line in
_request_firmware_load()
fw_priv->buf = NULL
which is run in timeout path
- then the abort() called from firmware_loading_store() may use a
freed fw buf
since the timeout path will free the fw buffer.
Considered clearing 'fw_priv->buf' in _request_firmware_load()() isn't
protected
by fw_lock now, so Guenter's patch can't avoid the race entirely.
I agree; my patch only protects one specific path, and was based on the
observation that access to fw_priv->buf is protected elsewhwere in the
code.
My suspicion was that fw_priv->buf was freed while waiting for the
mutex in
firmware_loading_store().
Your patch is more comprehensive.
OK, thanks for your reply.
I will post out one version for merge, and this one moves the
"fw_priv->buf = NULL;" into fw_load_abort() for simplifying change.
this is just to let you know that i've tested Ming Lei's latest patch.
thank you very much for the fix and the explanation.
--
nirinA
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