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 73F152C0F6D; Fri, 24 Apr 2026 15:29:07 +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=1777044547; cv=none; b=dCvVHj2kgaM3/OCgGuQV4zvVYtQvcNog9KDy6mxMPgeWGbzl0EIjAu4XyCIRYN2eHARm+G4g0h+C1zQz/ad/NnCSwRmFITZNq6FIgZMXbj7g2nwbfoeqddnMA9xMHA1xbcJALipDNbzxez+8QLHA0WdjrVPj1L81mEOiEwe0UeA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777044547; c=relaxed/simple; bh=z8g55jJxkVK65lBlfAd1QlVw49kpoWTm3+rI70O8CRM=; h=Date:To:From:Subject:Message-Id; b=Kqz9D4deRMG26p/+7SKVx9AjT1ZBHoWYXmQwDB39cSRsVOkxHE4yWiyDo70twEs4y3wK2FHAHEEXAwxH9X9KMhYkCupWgwZ+IRajrwz9/0QPl2RM5Qa1Uf+lb5Bjs6LKHNpesaL1jmLeY8KiIvfSBtiHqiXpq474VoLMin3B2Zg= 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=O0sLZ65E; 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="O0sLZ65E" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1C783C19425; Fri, 24 Apr 2026 15:29:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1777044547; bh=z8g55jJxkVK65lBlfAd1QlVw49kpoWTm3+rI70O8CRM=; h=Date:To:From:Subject:From; b=O0sLZ65El+HYcqC1sNvxuPLp3VigVgBEMQ6m6u0W0K9L/PMo1Ps/xDJ1erErcV1b3 gHVG9gTXA7fe3ynY3HMQoIv2/w0sjl6A75SKfmVx5V/P4SxHa4VQtNphI6m6G6Z2SZ rzAXgui4qY+GmfGbaG/t4WMPNbjNJEuUsjccGn3I= Date: Fri, 24 Apr 2026 08:29:06 -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@infradead.org,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-new branch Message-Id: <20260424152907.1C783C19425@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-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 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: Wed, 15 Apr 2026 20:39:37 -0700 Patch series "fix MAP_DROPPABLE not supported errno", v4. 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. The third patch fixes the MAP_DROPPABLE selftest so that it is run by the framework and skips if MAP_DROPPABLE is not supported. This patch (of 3): 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/20260416033939.49981-1-anthony.yznaga@oracle.com Link: https://lore.kernel.org/20260416033939.49981-2-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 (Arm) Acked-by: Vlastimil Babka (SUSE) Reported-by: Mark Brown Reviewed-by: Pedro Falcato Reviewed-by: Lorenzo Stoakes (Oracle) Cc: Jann Horn Cc: Jason A. Donenfeld Cc: Liam Howlett Cc: Michal Hocko Cc: Mike Rapoport Cc: Shuah Khan Cc: Suren Baghdasaryan 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 selftests-mm-run-the-map_droppable-selftest.patch