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From:   Yaohui Wang <yaohuiwang@linux.alibaba.com>
To:     dave.hansen@linux.intel.com, tglx@linutronix.de
Cc:     luto@kernel.org, peterz@infradead.org, mingo@redhat.com,
        bp@alien8.de, x86@kernel.org, linux-kernel@vger.kernel.org,
        luoben@linux.alibaba.com, yaohuiwang@linux.alibaba.com
Subject: [PATCH v3 2/2] kernel/resource: fix boundary judgment issues in find_next_iomem_res() and __walk_iomem_res_desc()
Date:   Mon, 21 Jun 2021 20:34:19 +0800
Message-Id: <20210621123419.2976-3-yaohuiwang@linux.alibaba.com>
In-Reply-To: <20210621123419.2976-1-yaohuiwang@linux.alibaba.com>
References: <20210621123419.2976-1-yaohuiwang@linux.alibaba.com>
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Memory resources are described with the start address and the inclusive
end address, which means for a resource with 1 byte length the start
address is the same as the end address.

find_next_iomem_res() and __walk_iomem_res_desc() ignore resources with
1 byte length, which prevents that ioremap_xxx(phys_addr, 1) is checked
whether it touches non-ioremappable resources.

Fixes: 010a93bf97c7 (resource: Fix find_next_iomem_res() iteration issue)
Fixes: b69c2e20f6e4 (resource: Clean it up a bit)
Signed-off-by: Yahui Wang <yaohuiwang@linux.alibaba.com>
Signed-off-by: Ben Luo <luoben@linux.alibaba.com>
---
 kernel/resource.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/resource.c b/kernel/resource.c
index ca9f5198a01f..31e371babfad 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -344,7 +344,7 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
 	if (!res)
 		return -EINVAL;
 
-	if (start >= end)
+	if (start > end)
 		return -EINVAL;
 
 	read_lock(&resource_lock);
@@ -392,7 +392,7 @@ static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
 	struct resource res;
 	int ret = -EINVAL;
 
-	while (start < end &&
+	while (start <= end &&
 	       !find_next_iomem_res(start, end, flags, desc, &res)) {
 		ret = (*func)(&res, arg);
 		if (ret)
-- 
2.25.1