From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1517957352; cv=none; d=google.com; s=arc-20160816; b=WxvMzTBzXrGT3+9P9zQd8HP6GpmQ/AwGt04x3bSMa+zUMOn9FJYwkdOWSdoLEMIUW9 C7CST3k3IF581yTNjcebHOw10R1cTNBwYyhgn3mfDQ6BCm6hmhMs95Lefkm70S86bHeF c7+7YMHXyEJx/tpclOsvUu4v1YBOzIfa1YImTo+IFJ+/AgpERKljiTCOxlNGlr6AsxGe HNAjdZDHp35qCXfL2kHHraUtSGv7CgcCHms0aw6sG8QXpu8I/z6MfIogN633mBTnbIyA hfYayhLkJWewJJ6Er35fMk0BOlkDKgTWOm4a/OHnDo2fKXFScrE9RN312+12VMENzDtt HxyQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject :arc-authentication-results; bh=XPB6dNZ8A+YPFr5lUMgHAE8B/Nk+PyGmYhmEkIXCMZQ=; b=KxxkMdM+DNXfVOh70l2b1dtILg9UJTuhd+6Qhv0f93YIXcn+Bcoz2T2BCgMOZF8kmq UuGcm4m7soFrz8W70dAvlEZ/nFpmyLrhXcUT6NTCPXthwlvFZU/b615kd8Px45g91sLS +rUsU9QXyFusf00om338XSomcXE8C1xVUVPv33Q89wqaPvtey/HxZFpE3zS/ETta0WNn 3qzzN0EXL2t2WmYwtqoxdwnAFbz+OZE0vJjN/SajVBo8znw6Bc+ns/6BvfAtij1wiGSV x/A5hkMso1J61gHkB+0GHBqf5Q5xtFmJq3C8HB/D7kZyLl6+h7kAORrhpBYzbGVaq3lK DkkQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of labbott@redhat.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=labbott@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of labbott@redhat.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=labbott@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com X-Google-Smtp-Source: AH8x2254cjpWaLOklsjcH2tolfx299FqI641ey5jyoQg/2jljorQN04iOwunBDKWxI03rJgf+lIJvw== Subject: Re: [PATCH v3] staging: android: ion: Zero CMA allocated memory To: Liam Mark , Sumit Semwal Cc: Dan Carpenter , Greg KH , linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org, linaro-mm-sig@lists.linaro.org References: From: Laura Abbott Message-ID: Date: Tue, 6 Feb 2018 14:49:09 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1590678153366118365?= X-GMAIL-MSGID: =?utf-8?q?1591693648791350091?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 01/26/2018 09:48 AM, Liam Mark wrote: > Since commit 204f672255c2 ("staging: android: ion: Use CMA APIs directly") > the CMA API is now used directly and therefore the allocated memory is no > longer automatically zeroed. > > Explicitly zero CMA allocated memory to ensure that no data is exposed to > userspace. > Acked-by: Laura Abbott > Fixes: 204f672255c2 ("staging: android: ion: Use CMA APIs directly") > Signed-off-by: Liam Mark > --- > Changes in v2: > - Clean up the commit message. > - Add 'Fixes:' > > Changes in v3: > - Add support for highmem pages > > drivers/staging/android/ion/ion_cma_heap.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/drivers/staging/android/ion/ion_cma_heap.c b/drivers/staging/android/ion/ion_cma_heap.c > index 86196ffd2faf..fa3e4b7e0c9f 100644 > --- a/drivers/staging/android/ion/ion_cma_heap.c > +++ b/drivers/staging/android/ion/ion_cma_heap.c > @@ -21,6 +21,7 @@ > #include > #include > #include > +#include > > #include "ion.h" > > @@ -51,6 +52,22 @@ static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer, > if (!pages) > return -ENOMEM; > > + if (PageHighMem(pages)) { > + unsigned long nr_clear_pages = nr_pages; > + struct page *page = pages; > + > + while (nr_clear_pages > 0) { > + void *vaddr = kmap_atomic(page); > + > + memset(vaddr, 0, PAGE_SIZE); > + kunmap_atomic(vaddr); > + page++; > + nr_clear_pages--; > + } > + } else { > + memset(page_address(pages), 0, size); > + } > + > table = kmalloc(sizeof(*table), GFP_KERNEL); > if (!table) > goto err; >