All of lore.kernel.org
 help / color / mirror / Atom feed
* [to-be-updated] mm-fix-mmap-errno-value-when-map_droppable-is-not-supported.patch removed from -mm tree
@ 2026-04-03 17:32 Andrew Morton
  0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2026-04-03 17:32 UTC (permalink / raw)
  To: mm-commits, vbabka, surenb, stable, shuah, rppt, pfalcato, mhocko,
	ljs, liam.howlett, jason, jannh, david, anthony.yznaga, akpm


The quilt patch titled
     Subject: mm: fix mmap errno value when MAP_DROPPABLE is not supported
has been removed from the -mm tree.  Its filename was
     mm-fix-mmap-errno-value-when-map_droppable-is-not-supported.patch

This patch was dropped because an updated version will be issued

------------------------------------------------------
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>
Acked-by: David Hildenbrand (Arm) <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

selftests-mm-verify-droppable-mappings-cannot-be-locked.patch


^ permalink raw reply	[flat|nested] 2+ messages in thread

* [to-be-updated] mm-fix-mmap-errno-value-when-map_droppable-is-not-supported.patch removed from -mm tree
@ 2026-04-24 15:26 Andrew Morton
  0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2026-04-24 15:26 UTC (permalink / raw)
  To: mm-commits, anthony.yznaga, akpm


The quilt patch titled
     Subject: mm: fix mmap errno value when MAP_DROPPABLE is not supported
has been removed from the -mm tree.  Its filename was
     mm-fix-mmap-errno-value-when-map_droppable-is-not-supported.patch

This patch was dropped because an updated version will be issued

------------------------------------------------------
From: Anthony Yznaga <anthony.yznaga@oracle.com>
Subject: mm: fix mmap errno value when MAP_DROPPABLE is not supported
Date: Thu, 2 Apr 2026 16:59:32 -0700

Patch series "fix MAP_DROPPABLE not supported errno".

Mark Brown reported seeing a regression in -next on 32 bit arm with the
mlock selftests.  Before exiting and marking the tests failed, the
following message was logged after an attempt to create a MAP_DROPPABLE
mapping:

Bail out! mmap error: Unknown error 524

It turns out error 524 is ENOTSUPP which is an error that userspace is not
supposed to see, but it indicates in this instance that MAP_DROPPABLE is
not supported.

The first patch changes the errno returned to EOPNOTSUPP.  The second
patch is a second version of a prior patch to introduce selftests to
verify locking behavior with droppable mappings with the additional change
to skip the tests when MAP_DROPPABLE is not supported.


This patch (of 2):

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 effect.

Link: https://lore.kernel.org/20260402235933.10588-1-anthony.yznaga@oracle.com
Link: https://lore.kernel.org/20260402235933.10588-2-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>
Acked-by: David Hildenbrand <david@kernel.org>
Reported-by: Mark Brown <broonie@kernel.org>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jason A. Donenfeld <jason@zx2c4.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
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

selftests-mm-verify-droppable-mappings-cannot-be-locked.patch


^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2026-04-24 15:26 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-04-24 15:26 [to-be-updated] mm-fix-mmap-errno-value-when-map_droppable-is-not-supported.patch removed from -mm tree Andrew Morton
  -- strict thread matches above, loose matches on Subject: below --
2026-04-03 17:32 Andrew Morton

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.