Re: [PATCH] netxen: Fix a sleep-in-atomic bug in netxen_nic_pci_mem_access_direct

From: Jia-Ju Bai
Date: Wed Jun 21 2017 - 02:30:24 EST

On 06/21/2017 02:11 PM, Kalle Valo wrote:
David Miller<davem@xxxxxxxxxxxxx> writes:

From: Jia-Ju Bai<baijiaju1990@xxxxxxx>
Date: Mon, 19 Jun 2017 10:48:53 +0800

The driver may sleep under a spin lock, and the function call path is:
netxen_nic_pci_mem_access_direct (acquire the lock by spin_lock)
ioremap --> may sleep

To fix it, the lock is released before "ioremap", and the lock is
acquired again after this function.

Signed-off-by: Jia-Ju Bai<baijiaju1990@xxxxxxx>
This style of change you are making is really starting to be a

You can't just drop locks like this, especially without explaining
why it's ok, and why the mutual exclusion this code was trying to
achieve is still going to be OK afterwards.

In fact, I see zero analysis of the locking situation here, why
it was needed in the first place, and why your change is OK in
that context.

Any locking change is delicate, and you must put the greatest of
care and consideration into it.

Just putting "unlock/lock" around the sleeping operation shows a
very low level of consideration for the implications of the change
you are making.

This isn't like making whitespace fixes, sorry...
We already tried to explain this to Jia-Ju during review of a wireless

Jia-Ju, you should listen to feedback. If you continue submitting random
patches like this makes it hard for maintainers to trust your patches


I am quite sorry for my incorrect patches, and I will listen carefully to your advice.
In fact, for some bugs and patches which I have reported before, I have not received the feedback of them, so I resent them a few days ago, including this patch.
Sorry for my mistake again.

Jia-Ju Bai