[PATCH v3] x86/ioremap: Use is_ioremap_addr() in iounmap()

[Max Ramanouski <max8rr8@gmail.com>]

Restrict iounmap() to memory allocated in ioremap region, by using
is_ioremap_addr(). Similarly to the generic iounmap() implementation.

Additionally, add warning in case there is an attempt to iounmap()
invalid memory, instead of silently exiting, thus helping to
avoid incorrect usage of iounmap().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Max Ramanouski <max8rr8@gmail.com>
---
 arch/x86/mm/ioremap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index aa7d279321ea..70b02fc61d93 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -11,6 +11,7 @@
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/ioport.h>
+#include <linux/ioremap.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/mmiotrace.h>
@@ -457,7 +458,7 @@ void iounmap(volatile void __iomem *addr)
 {
 	struct vm_struct *p, *o;
 
-	if ((void __force *)addr <= high_memory)
+	if (WARN_ON_ONCE(!is_ioremap_addr((void __force *)addr)))
 		return;
 
 	/*
-- 
2.45.2