[PATCH 1/3] s390/boot: Fix physical memory search range

[Vasily Gorbik <gor@linux.ibm.com>]

search_mem_end() calculates the number of 1MB blocks with a signed int
literal. CONFIG_MAX_PHYSMEM_BITS values of 51 and above either overflow
the signed int or shift beyond its width. This produces an invalid search
range when the binary-search memory detection fallback is used.

Use an unsigned long literal so the full supported physical address range
is represented.

Fixes: 4d14c2666b6b ("s390/mem_detect: replace tprot loop with binary search")
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---
 arch/s390/boot/physmem_info.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/boot/physmem_info.c b/arch/s390/boot/physmem_info.c
index 1f2ca5435838..0ebb2174713f 100644
--- a/arch/s390/boot/physmem_info.c
+++ b/arch/s390/boot/physmem_info.c
@@ -141,7 +141,7 @@ static int tprot(unsigned long addr)
 
 static unsigned long search_mem_end(void)
 {
-	unsigned long range = 1 << (MAX_PHYSMEM_BITS - 20); /* in 1MB blocks */
+	unsigned long range = 1UL << (MAX_PHYSMEM_BITS - 20); /* in 1MB blocks */
 	unsigned long offset = 0;
 	unsigned long pivot;
 
-- 
2.53.0