From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v2] xen/arm: Fix crash if last memory section is bigger than 1gb Date: Thu, 02 Oct 2014 15:50:29 +0100 Message-ID: <542D6635.3050109@linaro.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Frediano Ziglio Cc: Tim Deegan , Stefano Stabellini , Ian Campbell , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org Hi Frediano, On 10/02/2014 03:39 PM, Frediano Ziglio wrote: > setup_xenheap_mappings setup head memory on Arm 32 has a limit of 1gb. > On system with large memory is possible that there are no blocks of memory > smaller than 1gb leading xenheap_pages to be more than 1gb. > This cause memory errors trying to access heap after the 1gb limit. > > Signed-off-by: Frediano Ziglio > --- > xen/arch/arm/setup.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c > index 446de8a..e223d1b 100644 > --- a/xen/arch/arm/setup.c > +++ b/xen/arch/arm/setup.c > @@ -509,6 +509,7 @@ static void __init setup_mm(unsigned long > dtb_paddr, size_t dtb_size) > heap_pages = ram_pages; > xenheap_pages = (heap_pages/8 + 0x1fffUL) & ~0x1fffUL; > xenheap_pages = max(xenheap_pages, 128UL<<(20-PAGE_SHIFT)); > + xenheap_pages = min(xenheap_pages, 1UL<<(30-PAGE_SHIFT)); > > do > { > You forgot to add my Reviewed-by (gave on the latest version) and address one thing. There is a big comment in the code explaining the different constraint on to find the heap. You have to update it. I would replace the line "- must be at most 1/8 the total RAM in the system" by " - must be at most 1GB or 1/8 the total RAM in the system if less". Regards, -- Julien Grall