linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Keqian Zhu <zhukeqian1@huawei.com>
To: <linux-kernel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<iommu@lists.linux-foundation.org>
Cc: Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	James Morse <james.morse@arm.com>,
	"Suzuki K Poulose" <suzuki.poulose@arm.com>,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Mark Brown <broonie@kernel.org>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Alexios Zavras <alexios.zavras@intel.com>,
	<wanghaibin.wang@huawei.com>, <jiangkunkun@huawei.com>,
	Keqian Zhu <zhukeqian1@huawei.com>
Subject: [PATCH] iommu: Up front sanity check in the arm_lpae_map
Date: Sat, 5 Dec 2020 16:29:57 +0800	[thread overview]
Message-ID: <20201205082957.12544-1-zhukeqian1@huawei.com> (raw)

... then we have more chance to detect wrong code logic.

Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
---
 drivers/iommu/io-pgtable-arm.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index a7a9bc08dcd1..8ade72adab31 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -444,10 +444,6 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova,
 	arm_lpae_iopte prot;
 	long iaext = (s64)iova >> cfg->ias;
 
-	/* If no access, then nothing to do */
-	if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE)))
-		return 0;
-
 	if (WARN_ON(!size || (size & cfg->pgsize_bitmap) != size))
 		return -EINVAL;
 
@@ -456,6 +452,10 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova,
 	if (WARN_ON(iaext || paddr >> cfg->oas))
 		return -ERANGE;
 
+	/* If no access, then nothing to do */
+	if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE)))
+		return 0;
+
 	prot = arm_lpae_prot_to_pte(data, iommu_prot);
 	ret = __arm_lpae_map(data, iova, paddr, size, prot, lvl, ptep, gfp);
 	/*
-- 
2.23.0


             reply	other threads:[~2020-12-05  8:33 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-05  8:29 Keqian Zhu [this message]
2020-12-07 10:59 ` [PATCH] iommu: Up front sanity check in the arm_lpae_map Will Deacon
2020-12-07 11:37   ` zhukeqian
2020-12-07 12:01 ` Robin Murphy
2020-12-07 12:05   ` Will Deacon
2020-12-07 12:15     ` zhukeqian
2020-12-07 12:46       ` Robin Murphy
2020-12-07 13:36         ` zhukeqian

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201205082957.12544-1-zhukeqian1@huawei.com \
    --to=zhukeqian1@huawei.com \
    --cc=akpm@linux-foundation.org \
    --cc=alexios.zavras@intel.com \
    --cc=broonie@kernel.org \
    --cc=catalin.marinas@arm.com \
    --cc=iommu@lists.linux-foundation.org \
    --cc=james.morse@arm.com \
    --cc=jiangkunkun@huawei.com \
    --cc=joro@8bytes.org \
    --cc=julien.thierry.kdev@gmail.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=maz@kernel.org \
    --cc=robin.murphy@arm.com \
    --cc=sean.j.christopherson@intel.com \
    --cc=suzuki.poulose@arm.com \
    --cc=tglx@linutronix.de \
    --cc=wanghaibin.wang@huawei.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).