From: Dan Carpenter <dan.carpenter@oracle.com>
To: Fengguang Wu <fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Felipe Balbi <balbi-l0cyMroinI0@public.gmane.org>,
kernel-janitors-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state
Date: Wed, 12 Sep 2012 08:50:57 +0000 [thread overview]
Message-ID: <20120912085057.GC19396@mwanda> (raw)
In-Reply-To: <20120912082622.GB27847@localhost>
On Wed, Sep 12, 2012 at 04:26:22PM +0800, Fengguang Wu wrote:
> Hi Felipe,
>
> FYI, there are new smatch warnings show up in
>
> tree: git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git merge-result-for-greg
> head: 23953bde3e4d6aa8780dc054f6ad9882ac63f4f4
> commit: e918fa161f510136fce45a524e934fe20e62c8b1 [66/99] Merge tag 'gadget-for-v3.7' into merge-result-for-greg
>
> drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null))
Smatch prints out a lot of these warnings. I haven't looked at the
rules in a while, so maybe there is a bounce buffer somewhere where
it detects stack memory and allocates a DMA'able buffer?
It would be better if the function documentation for
usb_control_msg() said that the *data pointer had to be kmalloc()ed.
Also I wonder if Documentation/DMA-API-HOWTO.txt is out of data.
Are we allowed to DMA to vmalloc()ed memory yet?
regards,
dan carpenter
WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
To: Fengguang Wu <fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Felipe Balbi <balbi-l0cyMroinI0@public.gmane.org>,
kernel-janitors-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null))
Date: Wed, 12 Sep 2012 11:50:57 +0300 [thread overview]
Message-ID: <20120912085057.GC19396@mwanda> (raw)
In-Reply-To: <20120912082622.GB27847@localhost>
On Wed, Sep 12, 2012 at 04:26:22PM +0800, Fengguang Wu wrote:
> Hi Felipe,
>
> FYI, there are new smatch warnings show up in
>
> tree: git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git merge-result-for-greg
> head: 23953bde3e4d6aa8780dc054f6ad9882ac63f4f4
> commit: e918fa161f510136fce45a524e934fe20e62c8b1 [66/99] Merge tag 'gadget-for-v3.7' into merge-result-for-greg
>
> drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null))
Smatch prints out a lot of these warnings. I haven't looked at the
rules in a while, so maybe there is a bounce buffer somewhere where
it detects stack memory and allocates a DMA'able buffer?
It would be better if the function documentation for
usb_control_msg() said that the *data pointer had to be kmalloc()ed.
Also I wonder if Documentation/DMA-API-HOWTO.txt is out of data.
Are we allowed to DMA to vmalloc()ed memory yet?
regards,
dan carpenter
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next prev parent reply other threads:[~2012-09-12 8:50 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-12 8:26 [balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() e Fengguang Wu
2012-09-12 8:26 ` [balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null)) Fengguang Wu
2012-09-12 8:50 ` Dan Carpenter [this message]
2012-09-12 8:50 ` Dan Carpenter
2012-09-12 12:02 ` [balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state Felipe Balbi
2012-09-12 12:02 ` [balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null)) Felipe Balbi
[not found] ` <20120912120211.GC5732-S8G//mZuvNWo5Im9Ml3/Zg@public.gmane.org>
2012-09-12 12:09 ` [balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state Fengguang Wu
2012-09-12 12:09 ` [balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state() error: doing dma on the stack ((null)) Fengguang Wu
2012-09-12 13:11 ` [balbi-usb:merge-result-for-greg 66/99] drivers/usb/core/hub.c:2654 usb_get_hub_port_power_state Alan Stern
2012-09-12 14:41 ` Lan Tianyu
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