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From: Johan Hovold <johan@kernel.org>
To: Jia-Ju Bai <baijiaju1990@gmail.com>
Cc: davem@davemloft.net, andreas@kemnade.info, johan@kernel.org,
	johannes.berg@intel.com, stephen@networkplumber.org,
	Linyu.Yuan@alcatel-sbell.com.cn, linux-usb@vger.kernel.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: net: usb: hso: Replace GFP_ATOMIC with GFP_KERNEL in hso_create_device
Date: Tue, 10 Apr 2018 16:59:28 +0200	[thread overview]
Message-ID: <20180410145928.GC10795@localhost> (raw)

On Tue, Apr 10, 2018 at 10:35:24PM +0800, Jia-Ju Bai wrote:
> hso_create_device() is never called in atomic context.
> 
> The call chains ending up at hso_create_device() are:
> [1] hso_create_device() <- hso_create_bulk_serial_device() <- hso_probe()
> [2] hso_create_device() <- hso_create_mux_serial_device() <- hso_probe()
> [3] hso_create_device() <- hso_create_net_device() <- hso_probe()
> hso_probe() is set as ".probe" in struct usb_driver, 
> so it is not called in atomic context.
> 
> Despite never getting called from atomic context,
> hso_create_device() calls kzalloc() with GFP_ATOMIC,
> which does not sleep for allocation.
> GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
> which can sleep and improve the possibility of sucessful allocation.
> 
> This is found by a static analysis tool named DCNS written by myself.
> And I also manually check it.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>

Thanks for the patch. This looks good to me.

Reviewed-by: Johan Hovold <johan@kernel.org>

Johan
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WARNING: multiple messages have this Message-ID (diff)
From: Johan Hovold <johan@kernel.org>
To: Jia-Ju Bai <baijiaju1990@gmail.com>
Cc: davem@davemloft.net, andreas@kemnade.info, johan@kernel.org,
	johannes.berg@intel.com, stephen@networkplumber.org,
	Linyu.Yuan@alcatel-sbell.com.cn, linux-usb@vger.kernel.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: usb: hso: Replace GFP_ATOMIC with GFP_KERNEL in hso_create_device
Date: Tue, 10 Apr 2018 16:59:28 +0200	[thread overview]
Message-ID: <20180410145928.GC10795@localhost> (raw)
In-Reply-To: <1523370924-32425-1-git-send-email-baijiaju1990@gmail.com>

On Tue, Apr 10, 2018 at 10:35:24PM +0800, Jia-Ju Bai wrote:
> hso_create_device() is never called in atomic context.
> 
> The call chains ending up at hso_create_device() are:
> [1] hso_create_device() <- hso_create_bulk_serial_device() <- hso_probe()
> [2] hso_create_device() <- hso_create_mux_serial_device() <- hso_probe()
> [3] hso_create_device() <- hso_create_net_device() <- hso_probe()
> hso_probe() is set as ".probe" in struct usb_driver, 
> so it is not called in atomic context.
> 
> Despite never getting called from atomic context,
> hso_create_device() calls kzalloc() with GFP_ATOMIC,
> which does not sleep for allocation.
> GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
> which can sleep and improve the possibility of sucessful allocation.
> 
> This is found by a static analysis tool named DCNS written by myself.
> And I also manually check it.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>

Thanks for the patch. This looks good to me.

Reviewed-by: Johan Hovold <johan@kernel.org>

Johan

             reply	other threads:[~2018-04-10 14:59 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-10 14:59 Johan Hovold [this message]
2018-04-10 14:59 ` [PATCH] net: usb: hso: Replace GFP_ATOMIC with GFP_KERNEL in hso_create_device Johan Hovold
  -- strict thread matches above, loose matches on Subject: below --
2018-04-10 14:35 Jia-Ju Bai
2018-04-10 14:35 ` [PATCH] " Jia-Ju Bai

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