From: Binglei Wang <l3b2w1@gmail.com>
Date: Wed, 26 Jul 2023 14:28:23 +0000 (+0800)
Subject: dma-contiguous: check for memory region overlap
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3fa6456ebe13adab3ba1817c8e515a5b88f95dce;p=linux.git

dma-contiguous: check for memory region overlap

In the process of parsing the DTS, check whether the memory region
specified by the DTS CMA node area overlaps with the kernel text
memory space reserved by memblock before calling
early_init_fdt_scan_reserved_mem.

Signed-off-by: Binglei Wang <l3b2w1@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---

diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index f005c66f378c3..88c595e49e345 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -473,6 +473,11 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem)
 		return -EBUSY;
 	}
 
+	if (memblock_is_region_reserved(rmem->base, rmem->size)) {
+		pr_info("Reserved memory: overlap with other memblock reserved region\n");
+		return -EBUSY;
+	}
+
 	if (!of_get_flat_dt_prop(node, "reusable", NULL) ||
 	    of_get_flat_dt_prop(node, "no-map", NULL))
 		return -EINVAL;