From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3747066-1521227792-2-18070345011832442148 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no ("Email failed DMARC policy for domain") X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='com', MailFrom='org' X-Spam-charsets: cc='UTF-8', plain='UTF-8' X-IgnoreVacation: yes ("Email failed DMARC policy for domain") X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1521227792; b=IWTcRVkiG0F5LpzX7OI6fqo6xdK/tKGa800rbktoNgCO3a+ EoFQFm5gMr+BfVbHtlrJEo5pSKj4xD10ek/V/dsVa3I4Tee2aTNZJXiwMGD2Pxiy s/twnx63++6dio6V+D+f1ZoN90IwpGECEvEnJY5t2uy6lO155xBOh2CbKoDQoycz zo0gv9kHmr2yJ/7qjLhnC2LJuA9pvGY/e0ZAqiwqZKbAeN6eHcthejhAijWUkrn2 M2Vmvw02lcjV07aQvaFi0WLxkgkCTl9I1p5K1RU3FIyqqvFPH1qrMncK9WVsU69S jGKjqAno9D7MkSAKgr1QFKlee44wVfyE8U+ER0g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type :content-transfer-encoding:sender:list-id; s=arctest; t= 1521227792; bh=ANInufuiZumn6wLKIDpgoxvYwYbwvEvvMB0oJnWUE4w=; b=n 3KpXuxI5Trbq4hKBJIz14Sfm4HWuYY834nkOKXngMJdp6gLMcj5GodA5olSpFlAh jTAGcleVCp2Lw6oScAljr/hlhCGUNNmi3rp780uChzWG2o7hFJUSqC1brUVbjHga JbeRCOifAWPi3VEKFaeltztDKAEaLuwpPh4JA3enb+Ri51mH4UrNELXzPnLCziUm +heKuqMsIA9k3K4er2NUx4oUQL+wYPVfiIgANsr9ljOEGUbByUqDqMp1JurvF8PN F+d++ED2wsDTQVf/lNmJK6WuNNj5RwaTzlf5RvHfsIDUj78wcSZxsrbcaSIoxpyt VUpN4YuOAjIRqPjYCMgmQ== ARC-Authentication-Results: i=1; mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=fail (p=none,has-list-id=yes,d=none) header.from=redhat.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-category=clean score=-100 state=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=redhat.com header.result=pass header_is_org_domain=yes Authentication-Results: mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=fail (p=none,has-list-id=yes,d=none) header.from=redhat.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-category=clean score=-100 state=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=redhat.com header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752772AbeCPTQE (ORCPT ); Fri, 16 Mar 2018 15:16:04 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:34534 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752106AbeCPTOU (ORCPT ); Fri, 16 Mar 2018 15:14:20 -0400 From: jglisse@redhat.com To: linux-mm@kvack.org Cc: Andrew Morton , linux-kernel@vger.kernel.org, Ralph Campbell , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , stable@vger.kernel.org, Evgeny Baskakov , Mark Hairgrove , John Hubbard Subject: [PATCH 03/14] mm/hmm: HMM should have a callback before MM is destroyed v2 Date: Fri, 16 Mar 2018 15:14:08 -0400 Message-Id: <20180316191414.3223-4-jglisse@redhat.com> In-Reply-To: <20180316191414.3223-1-jglisse@redhat.com> References: <20180316191414.3223-1-jglisse@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: From: Ralph Campbell The hmm_mirror_register() function registers a callback for when the CPU pagetable is modified. Normally, the device driver will call hmm_mirror_unregister() when the process using the device is finished. However, if the process exits uncleanly, the struct_mm can be destroyed with no warning to the device driver. Changed since v1: - dropped VM_BUG_ON() - cc stable Signed-off-by: Ralph Campbell Signed-off-by: Jérôme Glisse Cc: stable@vger.kernel.org Cc: Evgeny Baskakov Cc: Mark Hairgrove Cc: John Hubbard --- include/linux/hmm.h | 10 ++++++++++ mm/hmm.c | 18 +++++++++++++++++- 2 files changed, 27 insertions(+), 1 deletion(-) diff --git a/include/linux/hmm.h b/include/linux/hmm.h index ef6044d08cc5..61b0e1c05ee1 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -218,6 +218,16 @@ enum hmm_update_type { * @update: callback to update range on a device */ struct hmm_mirror_ops { + /* release() - release hmm_mirror + * + * @mirror: pointer to struct hmm_mirror + * + * This is called when the mm_struct is being released. + * The callback should make sure no references to the mirror occur + * after the callback returns. + */ + void (*release)(struct hmm_mirror *mirror); + /* sync_cpu_device_pagetables() - synchronize page tables * * @mirror: pointer to struct hmm_mirror diff --git a/mm/hmm.c b/mm/hmm.c index 320545b98ff5..6088fa6ed137 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -160,6 +160,21 @@ static void hmm_invalidate_range(struct hmm *hmm, up_read(&hmm->mirrors_sem); } +static void hmm_release(struct mmu_notifier *mn, struct mm_struct *mm) +{ + struct hmm *hmm = mm->hmm; + struct hmm_mirror *mirror; + struct hmm_mirror *mirror_next; + + down_write(&hmm->mirrors_sem); + list_for_each_entry_safe(mirror, mirror_next, &hmm->mirrors, list) { + list_del_init(&mirror->list); + if (mirror->ops->release) + mirror->ops->release(mirror); + } + up_write(&hmm->mirrors_sem); +} + static void hmm_invalidate_range_start(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long start, @@ -185,6 +200,7 @@ static void hmm_invalidate_range_end(struct mmu_notifier *mn, } static const struct mmu_notifier_ops hmm_mmu_notifier_ops = { + .release = hmm_release, .invalidate_range_start = hmm_invalidate_range_start, .invalidate_range_end = hmm_invalidate_range_end, }; @@ -230,7 +246,7 @@ void hmm_mirror_unregister(struct hmm_mirror *mirror) struct hmm *hmm = mirror->hmm; down_write(&hmm->mirrors_sem); - list_del(&mirror->list); + list_del_init(&mirror->list); up_write(&hmm->mirrors_sem); } EXPORT_SYMBOL(hmm_mirror_unregister); -- 2.14.3