[PATCH 2/2 v2] make apply_to_page_range() more robust.

[mika.penttila]

From: Mika Penttilà <mika.penttila@xxxxxxxxxxxx>

Now the arm/arm64 don't trigger this BUG_ON() any more,
but WARN_ON() is here enough to catch buggy callers
but still let potential other !size callers pass with warning.

Signed-off-by: Mika Penttilà mika.penttila@xxxxxxxxxxxx
Reviewed-by: Pekka Enberg <penberg@xxxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>

---
 mm/memory.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/memory.c b/mm/memory.c
index 30991f8..9178ee6 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1871,7 +1871,9 @@ int apply_to_page_range(struct mm_struct *mm, unsigned long addr,
 	unsigned long end = addr + size;
 	int err;
 
-	BUG_ON(addr >= end);
+	if (WARN_ON(addr >= end))
+		return -EINVAL;
+
 	pgd = pgd_offset(mm, addr);
 	do {
 		next = pgd_addr_end(addr, end);
-- 
1.9.1