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Date: Sat, 1 Dec 2012 21:39:29 +0300
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Joonsoo Kim <js1304@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        devel@driverdev.osuosl.org, Robert Love <rlove@google.com>,
        Brian Swetland <swetland@google.com>, linux-kernel@vger.kernel.org,
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        John Stultz <john.stultz@linaro.org>, Colin Cross <ccross@android.com>,
        Android Kernel Team <kernel-team@android.com>
Subject: Re: [RFC PATCH] staging, android, ashmem: invalidate pin/unpin ioctl
 for private map
Message-ID: <20121201183929.GA6568@mwanda>
References: <1354297557-24486-1-git-send-email-js1304@gmail.com>
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On Sat, Dec 01, 2012 at 02:45:57AM +0900, Joonsoo Kim wrote:
> @@ -614,21 +616,35 @@ static int ashmem_pin_unpin(struct ashmem_area *asma, unsigned long cmd,
>  	pgstart = pin.offset / PAGE_SIZE;
>  	pgend = pgstart + (pin.len / PAGE_SIZE) - 1;
>  
> -	mutex_lock(&ashmem_mutex);
> +	if (asma->shared_mapping) {
> +		mutex_lock(&ashmem_mutex);

Wouldn't we need to hold the mutex while we check the
->shared_mapping?

regards,
dan carpenter