[PATCH v3 2/2] kernel/resource: fix boundary judgment issues in find_next_iomem_res() and __walk_iomem_res_desc()

From: Yaohui Wang
Date: Mon Jun 21 2021 - 08:35:56 EST


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@xxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Luo <luoben@xxxxxxxxxxxxxxxxx>
---
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