+ mm-fix-mmap-errno-value-when-map_droppable-is-not-supported.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: fix mmap errno value when MAP_DROPPABLE is not supported
has been added to the -mm mm-new branch.  Its filename is
     mm-fix-mmap-errno-value-when-map_droppable-is-not-supported.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-fix-mmap-errno-value-when-map_droppable-is-not-supported.patch

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

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: Anthony Yznaga <anthony.yznaga@oracle.com>
Subject: mm: fix mmap errno value when MAP_DROPPABLE is not supported
Date: Wed, 1 Apr 2026 17:34:16 -0700

On configs where MAP_DROPPABLE is not supported (currently any 32-bit
config except for PPC32), mmap fails with errno set to ENOTSUPP.  However,
ENOTSUPP is not a standard error value that userspace knows about.  The
acceptable userspace-visible errno to use is EOPNOTSUPP.  checkpatch.pl
has a warning to this affect.

Link: https://lkml.kernel.org/r/20260402003417.438037-2-anthony.yznaga@oracle.com
Fixes: 9651fcedf7b9 ("mm: add MAP_DROPPABLE for designating always lazily freeable mappings")
Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jason A. Donenfeld <jason@zx2c4.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

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

--- a/mm/mmap.c~mm-fix-mmap-errno-value-when-map_droppable-is-not-supported
+++ a/mm/mmap.c
@@ -504,7 +504,7 @@ unsigned long do_mmap(struct file *file,
 			break;
 		case MAP_DROPPABLE:
 			if (VM_DROPPABLE == VM_NONE)
-				return -ENOTSUPP;
+				return -EOPNOTSUPP;
 			/*
 			 * A locked or stack area makes no sense to be droppable.
 			 *
_

Patches currently in -mm which might be from anthony.yznaga@oracle.com are

mm-fix-mmap-errno-value-when-map_droppable-is-not-supported.patch