[merged mm-stable] alsa-us122l-mark-hwdep-mappings-vm_mixedmap.patch removed from -mm tree

[merged mm-stable] alsa-us122l-mark-hwdep-mappings-vm_mixedmap.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: ALSA: us122l: mark hwdep mappings VM_MIXEDMAP
has been removed from the -mm tree.  Its filename was
     alsa-us122l-mark-hwdep-mappings-vm_mixedmap.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
Subject: ALSA: us122l: mark hwdep mappings VM_MIXEDMAP
Date: Fri, 23 Oct 2026 11:21:31 +0100

mm has recently moved to a strict model which requires any driver which
clears VMA_MAYWRITE_BIT to be mapping non-mm-managed memory
(VMA_PFNMAP_BIT or VMA_MIXEDMAP_BIT), failing any such mmap() with an
error and a kernel warning - see "mm/vma: only allow mmap to clear
VMA_MAYWRITE_BIT if not mm-managed".

However, simultaneous to this, commit 71c610aeb177 ("ALSA: us122l: Prevent
write upgrades for read mappings") updated us122l to clear
VMA_MAYWRITE_BIT without marking the region with either VMA_PFNMAP_BIT or
VMA_MIXEDMAP_BIT.

vm_insert_pages() and friends set this automatically, however this driver
maps its pre-allocated pages from a fault handler, so never calls these.

Simply set the flag in usb_stream_hwdep_mmap() to resolve the issue.  This
correctly marks the mapping as one whose pages core mm does not manage,
which has no meaningful impact for this driver beyond preventing the
mmap() from failing.

Link: https://lore.kernel.org/20261023-fix-us122l-mixedmap-v1-1-e7bdd053850f@kernel.org
Fixes: 71c610aeb177 ("ALSA: us122l: Prevent write upgrades for read mappings")
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: David Carlier <devnexen@gmail.com>
Closes: https://lore.kernel.org/20261018025905.201296-1-devnexen@gmail.com
Acked-by: Takashi Iwai <tiwai@suse.de>
Cc: Kazuki Hanai <hnkz.64@gmail.com>
Cc: Jaroslav Kysela <perex@perex.cz>
---

 sound/usb/usx2y/us122l.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/sound/usb/usx2y/us122l.c~alsa-us122l-mark-hwdep-mappings-vm_mixedmap
+++ a/sound/usb/usx2y/us122l.c
@@ -193,7 +193,7 @@ static int usb_stream_hwdep_mmap(struct
 	}
 
 	area->vm_ops = &usb_stream_hwdep_vm_ops;
-	vm_flags_set(area, VM_DONTDUMP);
+	vm_flags_set(area, VM_MIXEDMAP | VM_DONTDUMP);
 	if (!read)
 		vm_flags_set(area, VM_DONTEXPAND);
 	area->vm_private_data = us122l;
_

Patches currently in -mm which might be from ljs@kernel.org are

mm-vma-fix-expansion-of-vma_mixedmap_bit-vmas.patch
mm-do-not-unintentionally-overwrite-atomic-vma-flags.patch
mm-vma-avoid-losing-atomic-vma-flags-when-setting-sticky-vma-flags.patch