[PATCH 9/9] dma-debug: Use memory_intersects() directly

From: Kefeng Wang
Date: Sat Jun 26 2021 - 03:27:38 EST


Use memory_intersects() directly instead of private overlap() function.

Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
kernel/dma/debug.c | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index 14de1271463f..8ef737223999 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -1066,20 +1066,10 @@ static void check_for_stack(struct device *dev,
}
}

-static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
-{
- unsigned long a1 = (unsigned long)addr;
- unsigned long b1 = a1 + len;
- unsigned long a2 = (unsigned long)start;
- unsigned long b2 = (unsigned long)end;
-
- return !(b1 <= a2 || a1 >= b2);
-}
-
static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
{
- if (overlap(addr, len, _stext, _etext) ||
- overlap(addr, len, __start_rodata, __end_rodata))
+ if (memory_intersects(_stext, _etext, addr, len) ||
+ memory_intersects(__start_rodata, __end_rodata, addr, len))
err_printk(dev, NULL, "device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
}

--
2.26.2