[135/212] include/linux/mmzone.h: avoid a warning in sparse memory support

Commit Message

Andrew Morton Sept. 2, 2021, 9:57 p.m. UTC

From: Matthew Wilcox <[e-mail]>
Subject: include/linux/mmzone.h: avoid a warning in sparse memory support

cppcheck warns that we're possibly losing information by shifting an int. 
It's a false positive, because we don't allow for a NUMA node ID that
large, but if we ever change SECTION_NID_SHIFT, it could become a problem,
and in any case this is usually a legitimate warning.  Fix it by adding
the necessary cast, which makes the compiler generate the right code.

Link: https://lkml.kernel.org/r/[e-mail]
Link: https://lkml.kernel.org/r/[e-mail]
Cc: Mike Rapoport <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/sparse.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

--- a/mm/sparse.c~avoid-a-warning-in-sparse-memory-support
+++ a/mm/sparse.c
@@ -117,7 +117,7 @@  static inline int sparse_index_init(unsi
  */
 static inline unsigned long sparse_encode_early_nid(int nid)
 {
-	return (nid << SECTION_NID_SHIFT);
+	return ((unsigned long)nid << SECTION_NID_SHIFT);
 }
 
 static inline int sparse_early_nid(struct mem_section *section)