From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8E9E42248A5; Fri, 3 Apr 2026 17:37:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775237858; cv=none; b=qqYeQYBd2/XbsWFEESePVKbIA0/SEN5Sl+zeUbgHdu7gAwQKaLA28LzqTa3pCSy4QYWPmfAsAhnF24522mEmCqIw7V50EHxZo+7UP4WQMi3Ocomzc4TIDSW0rQ/W7PZyT0ALyBkEf1RC3t2KCZiYWxE4Pe0YYWJRbifOPbTJ4Gk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775237858; c=relaxed/simple; bh=Juyu0y0I7u0FUKOOGT6Lg8UpSGHgVDhvKFGuqHaUDng=; h=Date:To:From:Subject:Message-Id; b=RCjtHIKDZmDNJk/22KUjMPkNr8WT0lYSET7qrcOQ6s0cbURgET692tOgzEQ+qJb4iTcyDZknMlsVZk48nE3m7wqjXdCkhuuVr+0y/YUOGqA758xO7rFHMXgQ4A2J5wBrho/y54vNSLElXlHjIM52ziPX/wK+ol4pBlM/khyhYaY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=eQrK2ogI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="eQrK2ogI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24EE8C4CEF7; Fri, 3 Apr 2026 17:37:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1775237858; bh=Juyu0y0I7u0FUKOOGT6Lg8UpSGHgVDhvKFGuqHaUDng=; h=Date:To:From:Subject:From; b=eQrK2ogI22G0H19mJuL11Eo7FMW2f9vSUiYNB9yVq3JOMOfKrNSIfyZbmHalLI3si u6hz/iHoFihIe/hFcr3t6jyA1gl6gVZQ9lM9YESVTc2KVRXU/2O+1P/4VLvZwNqhJD 7iaI4LKyMT6nlloCesQvFg6IHNXRjjGUsewhp2yM= Date: Fri, 03 Apr 2026 10:37:37 -0700 To: mm-commits@vger.kernel.org,vbabka@kernel.org,surenb@google.com,stable@vger.kernel.org,shuah@kernel.org,rppt@kernel.org,pfalcato@suse.de,mhocko@suse.com,ljs@kernel.org,liam.howlett@oracle.com,jason@zx2c4.com,jannh@google.com,david@kernel.org,broonie@kernel.org,anthony.yznaga@oracle.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-fix-mmap-errno-value-when-map_droppable-is-not-supported.patch added to mm-unstable branch Message-Id: <20260403173738.24EE8C4CEF7@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: fix mmap errno value when MAP_DROPPABLE is not supported has been added to the -mm mm-unstable 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-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 various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Anthony Yznaga 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 additonal 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://lkml.kernel.org/r/20260402235933.10588-1-anthony.yznaga@oracle.com Link: https://lkml.kernel.org/r/20260402235933.10588-2-anthony.yznaga@oracle.com Fixes: 9651fcedf7b9 ("mm: add MAP_DROPPABLE for designating always lazily freeable mappings") Signed-off-by: Anthony Yznaga Acked-by: David Hildenbrand Reported-by: Mark Brown Cc: Jann Horn Cc: Jason A. Donenfeld Cc: Liam Howlett Cc: Lorenzo Stoakes (Oracle) Cc: Michal Hocko Cc: Mike Rapoport Cc: Pedro Falcato Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton --- 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 selftests-mm-verify-droppable-mappings-cannot-be-locked.patch