Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Thu, 10 Oct 2019 00:36:10 +0300
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     James Bottomley <jejb@linux.ibm.com>
Cc:     linux-integrity@vger.kernel.org, Peter Huewe <peterhuewe@gmx.de>,
        Jason Gunthorpe <jgg@ziepe.ca>, Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 1/2] tpm: Use GFP_KERNEL for allocating struct tpm_buf
Message-ID: <20191009213559.GA30044@linux.intel.com>
References: <20191003185103.26347-1-jarkko.sakkinen@linux.intel.com>
 <20191003185103.26347-2-jarkko.sakkinen@linux.intel.com>
 <1570148716.10818.19.camel@linux.ibm.com>
 <20191006095005.GA7660@linux.intel.com>
 <1570475528.4242.2.camel@linux.ibm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1570475528.4242.2.camel@linux.ibm.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, Oct 07, 2019 at 12:12:08PM -0700, James Bottomley wrote:
> From: James Bottomley <James.Bottomley@HansenPartnership.com>
> Subject: [PATCH] tpm: use GFP kernel for tpm_buf allocations
> 
> The current code uses GFP_HIGHMEM, which is wrong because GFP_HIGHMEM
> (on 32 bit systems) is memory ordinarily inaccessible to the kernel
> and should only be used for allocations affecting userspace.  In order
> to make highmem visible to the kernel on 32 bit it has to be kmapped,
> which consumes valuable entries in the kmap region.  Since the tpm_buf
> is only ever used in the kernel, switch to using a GFP_KERNEL
> allocation so as not to waste kmap space on 32 bits.
> 
> Fixes: a74f8b36352e (tpm: introduce tpm_buf)
> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

Pushed to master branch.

/Jarkko