From: Robin Murphy <robin.murphy@arm.com>
To: Yong Wu <yong.wu@mediatek.com>, Will Deacon <will.deacon@arm.com>,
Joerg Roedel <joro@8bytes.org>,
Matthias Brugger <matthias.bgg@gmail.com>
Cc: Tomasz Figa <tfiga@google.com>,
linux-mediatek@lists.infradead.org, srv_heupstream@mediatek.com,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
iommu@lists.linux-foundation.org, youlin.pei@mediatek.com,
Nicolas Boichat <drinkcat@chromium.org>,
CK Hu <ck.hu@mediatek.com>
Subject: Re: [PATCH] iommu/io-pgtable-arm-v7s: Don't check PHYS_OFFSET if RAMDOMIZE_BASE is enabled
Date: Wed, 12 Dec 2018 13:39:55 +0000 [thread overview]
Message-ID: <50292758-47b1-1d08-5827-f7bdb3c33e1c@arm.com> (raw)
In-Reply-To: <1544619737-6313-1-git-send-email-yong.wu@mediatek.com>
On 12/12/2018 13:02, Yong Wu wrote:
> If CONFIG_RANDOMIZE_BASE is enabled, the "memstart_addr" will be updated
> randomly, then the PHYS_OFFSET may be random.
Oh, I hadn't ever realised that, good catch. However, since 29859aeb8a6e
I think we should probably just remove this check altogether.
> Fixes: 82db33dc5e49 ("iommu/io-pgtable-arm: Check for v7s-incapable
> systems")
Note that this alone wouldn't be sufficient for stable prior to 4.18,
since CONFIG_RANDOMIZE_BASE would then allow the original crash to
happen again.
Robin.
> Reported-by: CK Hu <ck.hu@mediatek.com>
> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> ---
> drivers/iommu/io-pgtable-arm-v7s.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
> index 445c3bd..70941e6 100644
> --- a/drivers/iommu/io-pgtable-arm-v7s.c
> +++ b/drivers/iommu/io-pgtable-arm-v7s.c
> @@ -709,7 +709,7 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
> {
> struct arm_v7s_io_pgtable *data;
>
> -#ifdef PHYS_OFFSET
> +#if defined(PHYS_OFFSET) && !defined(CONFIG_RANDOMIZE_BASE)
> if (upper_32_bits(PHYS_OFFSET))
> return NULL;
> #endif
>
next prev parent reply other threads:[~2018-12-12 13:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-12 13:02 [PATCH] iommu/io-pgtable-arm-v7s: Don't check PHYS_OFFSET if RAMDOMIZE_BASE is enabled Yong Wu
2018-12-12 13:39 ` Robin Murphy [this message]
2018-12-13 2:24 ` Yong Wu
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