+ mm-apply-__must_check-to-vmap_pages_range_noflush.patch added to mm-unstable branch

+ mm-apply-__must_check-to-vmap_pages_range_noflush.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: apply __must_check to vmap_pages_range_noflush()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-apply-__must_check-to-vmap_pages_range_noflush.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-apply-__must_check-to-vmap_pages_range_noflush.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Alexander Potapenko <glider@google.com>
Subject: mm: apply __must_check to vmap_pages_range_noflush()
Date: Thu, 13 Apr 2023 15:12:23 +0200

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.

Link: https://lkml.kernel.org/r/20230413131223.4135168-4-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Dipanjan Das <mail.dipanjan.das@gmail.com>
  Link: https://lore.kernel.org/linux-mm/CANX2M5ZRrRA64k0hOif02TjmY9kbbO2aCBPyq79es34RXZ=cAw@mail.gmail.com/
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/internal.h |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

--- a/mm/internal.h~mm-apply-__must_check-to-vmap_pages_range_noflush
+++ a/mm/internal.h
@@ -906,7 +906,7 @@ size_t splice_folio_into_pipe(struct pip
  */
 #ifdef CONFIG_MMU
 void __init vmalloc_init(void);
-int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
+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 void vmalloc_init(void)
@@ -914,16 +914,16 @@ static inline void vmalloc_init(void)
 }
 
 static inline
-int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
+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);
 
_

Patches currently in -mm which might be from glider@google.com are

mm-kmsan-handle-alloc-failures-in-kmsan_vmap_pages_range_noflush.patch
mm-kmsan-handle-alloc-failures-in-kmsan_ioremap_page_range.patch
mm-kmsan-apply-__must_check-to-non-void-functions.patch
mm-apply-__must_check-to-vmap_pages_range_noflush.patch