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 9F89115D5A6 for ; Thu, 2 May 2024 15:29:53 +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=1714663793; cv=none; b=Z3iZG/3EKGJNfzlLwZmjqUfwzEUqN5v6tET/+0sM3RF1aondn+5Obere/6GovdWRk05+YC6LTVHZKHWmGGNw90CSF+hHxAHkrJ+wHm03P4qG8lACza15LYHWnmeLHKRKmmtEP0zmmBCkBZ2k9pks5twSLwsNlSAzxviVpwoApj0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714663793; c=relaxed/simple; bh=4NlER2WVPQxfsBSYWAbaqCGVXk68Nuu4CUindzWEYPc=; h=Date:To:From:Subject:Message-Id; b=KNl07V8MSJgQt+CO9RTU0xH/ihbLYKzrZOYbC8NjoRXuUzar0JXuE+vRqUFBan2eAR3YHmQ+bv5Fp+XPKyiJU+DMCMWU6NIGbBKpBiZms0vPz4PTCigAFew2B0fiUsr4HIe8oAmzXyr7+JVoDSSS/v7btSNet4JuDx7TISJWaJc= 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=pcyWpFlS; 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="pcyWpFlS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0198DC113CC; Thu, 2 May 2024 15:29:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1714663793; bh=4NlER2WVPQxfsBSYWAbaqCGVXk68Nuu4CUindzWEYPc=; h=Date:To:From:Subject:From; b=pcyWpFlS69gAblK6mY341qRgmjdF0HYcXt687fs0PC77EoYQztPukXDj+6mX8XaBc 2H4ny18sUcPcUYt59EwlXK+/Jc06Y3hBSazJVKYwj6OpsVKRzq563of6ENQp88TDl9 jPJfPNtOb6AvaV4bgzYuuynvlXgXHEUWrC4PH7z8= Date: Thu, 02 May 2024 08:29:51 -0700 To: mm-commits@vger.kernel.org,nao.horiguchi@gmail.com,linmiaohe@huawei.com,jane.chu@oracle.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-memory-failure-send-sigbus-in-the-event-of-thp-split-fail.patch added to mm-unstable branch Message-Id: <20240502152953.0198DC113CC@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/memory-failure: send SIGBUS in the event of thp split fail has been added to the -mm mm-unstable branch. Its filename is mm-memory-failure-send-sigbus-in-the-event-of-thp-split-fail.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memory-failure-send-sigbus-in-the-event-of-thp-split-fail.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 the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Jane Chu Subject: mm/memory-failure: send SIGBUS in the event of thp split fail Date: Wed, 1 May 2024 17:24:58 -0600 When handle hwpoison in a GUP longterm pin'ed thp page, try_to_split_thp_page() will fail. And at this point, there is little else the kernel could do except sending a SIGBUS to the user process, thus give it a chance to recover. Link: https://lkml.kernel.org/r/20240501232458.3919593-4-jane.chu@oracle.com Signed-off-by: Jane Chu Cc: Miaohe Lin Cc: Naoya Horiguchi Signed-off-by: Andrew Morton --- mm/memory-failure.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) --- a/mm/memory-failure.c~mm-memory-failure-send-sigbus-in-the-event-of-thp-split-fail +++ a/mm/memory-failure.c @@ -2162,6 +2162,37 @@ out: return rc; } +/* + * The calling condition is as such: thp split failed, page might have + * been GUP longterm pinned, not much can be done for recovery. + * But a SIGBUS should be delivered with vaddr provided so that the user + * application has a chance to recover. Also, application processes' + * election for MCE early killed will be honored. + */ +static int kill_procs_now(struct page *p, unsigned long pfn, int flags, + struct page *hpage) +{ + struct folio *folio = page_folio(hpage); + LIST_HEAD(tokill); + int res = -EHWPOISON; + + /* deal with user pages only */ + if (PageReserved(p) || PageSlab(p) || PageTable(p) || PageOffline(p)) + res = -EBUSY; + if (!(PageLRU(hpage) || PageHuge(p))) + res = -EBUSY; + + if (res == -EHWPOISON) { + collect_procs(folio, p, &tokill, flags & MF_ACTION_REQUIRED); + kill_procs(&tokill, true, pfn, flags); + } + + if (flags & MF_COUNT_INCREASED) + put_page(p); + + return res; +} + /** * memory_failure - Handle memory failure of a page. * @pfn: Page Number of the corrupted page @@ -2291,6 +2322,11 @@ try_again: */ folio_set_has_hwpoisoned(folio); if (try_to_split_thp_page(p) < 0) { + if (flags & MF_ACTION_REQUIRED) { + pr_err("%#lx: thp split failed\n", pfn); + res = kill_procs_now(p, pfn, flags, hpage); + goto unlock_mutex; + } res = action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED); goto unlock_mutex; } _ Patches currently in -mm which might be from jane.chu@oracle.com are mm-memory-failure-try-to-send-sigbus-even-if-unmap-failed.patch mm-madvise-add-mf_action_required-to-madvisemadv_hwpoison.patch mm-memory-failure-send-sigbus-in-the-event-of-thp-split-fail.patch