From:   <yf.wang@mediatek.com>
To:     Will Deacon <will@kernel.org>, Robin Murphy <robin.murphy@arm.com>,
        "Joerg Roedel" <joro@8bytes.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        "moderated list:ARM SMMU DRIVERS" 
        <linux-arm-kernel@lists.infradead.org>,
        "open list:IOMMU DRIVERS" <iommu@lists.linux-foundation.org>,
        open list <linux-kernel@vger.kernel.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>
CC:     <wsd_upstream@mediatek.com>, Libo Kang <Libo.Kang@mediatek.com>,
        Yong Wu <Yong.Wu@mediatek.com>,
        Guangming Cao <Guangming.Cao@mediatek.com>,
        "Yunfei Wang" <yf.wang@mediatek.com>
Subject: [PATCH] iommu/io-pgtable-arm-v7s: Add error handle for page table allocation failure
Date:   Tue, 7 Dec 2021 10:47:22 +0800
Message-ID: <20211207024723.25751-1-yf.wang@mediatek.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

From: Yunfei Wang <yf.wang@mediatek.com>

In __arm_v7s_alloc_table function:
iommu call kmem_cache_alloc to allocate page table, this function
allocate memory may fail, when kmem_cache_alloc fails to allocate
table, call virt_to_phys will be abnomal and return unexpected phys
and goto out_free, then call kmem_cache_free to release table will
trigger KE, __get_free_pages and free_pages have similar problem,
so add error handle for page table allocation failure.

Signed-off-by: Yunfei Wang <yf.wang@mediatek.com>
---
 drivers/iommu/io-pgtable-arm-v7s.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index bfb6acb651e5..d84240308f4b 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -246,6 +246,12 @@ static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp,
 			__GFP_ZERO | ARM_V7S_TABLE_GFP_DMA, get_order(size));
 	else if (lvl == 2)
 		table = kmem_cache_zalloc(data->l2_tables, gfp);
+
+	if (!table) {
+		dev_err(dev, "Page table allocation failure lvl:%d\n", lvl);
+		return NULL;
+	}
+
 	phys = virt_to_phys(table);
 	if (phys != (arm_v7s_iopte)phys) {
 		/* Doesn't fit in PTE */
-- 
2.18.0