[PATCH v2 4/4] mm: apply __must_check to vmap_pages_range_noflush()

From: Alexander Potapenko
Date: Thu Apr 13 2023 - 09:13:09 EST


To prevent errors when vmap_pages_range_noflush() or
__vmap_pages_range_noflush() silently fail (see the link below for an
example), annotate them with __must_check so that the callers do not
unconditionally assume the mapping succeeded.

Reported-by: Dipanjan Das <mail.dipanjan.das@xxxxxxxxx>
Link: https://lore.kernel.org/linux-mm/CANX2M5ZRrRA64k0hOif02TjmY9kbbO2aCBPyq79es34RXZ=cAw@xxxxxxxxxxxxxx/
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
---
mm/internal.h | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/mm/internal.h b/mm/internal.h
index 7920a8b7982ec..a646cf7c41e8a 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -833,20 +833,20 @@ size_t splice_folio_into_pipe(struct pipe_inode_info *pipe,
* mm/vmalloc.c
*/
#ifdef CONFIG_MMU
-int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
- pgprot_t prot, struct page **pages, unsigned int page_shift);
+int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end,
+ pgprot_t prot, struct page **pages, unsigned int page_shift);
#else
static inline
-int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
- pgprot_t prot, struct page **pages, unsigned int page_shift)
+int __must_check vmap_pages_range_noflush(unsigned long addr, unsigned long end,
+ pgprot_t prot, struct page **pages, unsigned int page_shift)
{
return -EINVAL;
}
#endif

-int __vmap_pages_range_noflush(unsigned long addr, unsigned long end,
- pgprot_t prot, struct page **pages,
- unsigned int page_shift);
+int __must_check __vmap_pages_range_noflush(
+ unsigned long addr, unsigned long end, pgprot_t prot,
+ struct page **pages, unsigned int page_shift);

void vunmap_range_noflush(unsigned long start, unsigned long end);

--
2.40.0.577.gac1e443424-goog