From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:53038 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752035AbdHGUcm (ORCPT ); Mon, 7 Aug 2017 16:32:42 -0400 Subject: Patch "userfaultfd: non-cooperative: notify about unmap of destination during mremap" has been added to the 4.12-stable tree To: rppt@linux.vnet.ibm.com, aarcange@redhat.com, akpm@linux-foundation.org, gregkh@linuxfoundation.org, torvalds@linux-foundation.org, xemul@virtuozzo.com Cc: , From: Date: Mon, 07 Aug 2017 13:32:42 -0700 Message-ID: <150213796220844@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled userfaultfd: non-cooperative: notify about unmap of destination during mremap to the 4.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: userfaultfd-non-cooperative-notify-about-unmap-of-destination-during-mremap.patch and it can be found in the queue-4.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From b22823719302e88d0e2a6bb06433bd97b175a8d8 Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Wed, 2 Aug 2017 13:31:55 -0700 Subject: userfaultfd: non-cooperative: notify about unmap of destination during mremap From: Mike Rapoport commit b22823719302e88d0e2a6bb06433bd97b175a8d8 upstream. When mremap is called with MREMAP_FIXED it unmaps memory at the destination address without notifying userfaultfd monitor. If the destination were registered with userfaultfd, the monitor has no way to distinguish between the old and new ranges and to properly relate the page faults that would occur in the destination region. Fixes: 897ab3e0c49e ("userfaultfd: non-cooperative: add event for memory unmaps") Link: http://lkml.kernel.org/r/1500276876-3350-1-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport Acked-by: Pavel Emelyanov Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/mremap.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/mm/mremap.c +++ b/mm/mremap.c @@ -429,6 +429,7 @@ static struct vm_area_struct *vma_to_res static unsigned long mremap_to(unsigned long addr, unsigned long old_len, unsigned long new_addr, unsigned long new_len, bool *locked, struct vm_userfaultfd_ctx *uf, + struct list_head *uf_unmap_early, struct list_head *uf_unmap) { struct mm_struct *mm = current->mm; @@ -447,7 +448,7 @@ static unsigned long mremap_to(unsigned if (addr + old_len > new_addr && new_addr + new_len > addr) goto out; - ret = do_munmap(mm, new_addr, new_len, NULL); + ret = do_munmap(mm, new_addr, new_len, uf_unmap_early); if (ret) goto out; @@ -515,6 +516,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, a unsigned long charged = 0; bool locked = false; struct vm_userfaultfd_ctx uf = NULL_VM_UFFD_CTX; + LIST_HEAD(uf_unmap_early); LIST_HEAD(uf_unmap); if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE)) @@ -542,7 +544,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, a if (flags & MREMAP_FIXED) { ret = mremap_to(addr, old_len, new_addr, new_len, - &locked, &uf, &uf_unmap); + &locked, &uf, &uf_unmap_early, &uf_unmap); goto out; } @@ -622,6 +624,7 @@ out: up_write(¤t->mm->mmap_sem); if (locked && new_len > old_len) mm_populate(new_addr + old_len, new_len - old_len); + userfaultfd_unmap_complete(mm, &uf_unmap_early); mremap_userfaultfd_complete(&uf, addr, new_addr, old_len); userfaultfd_unmap_complete(mm, &uf_unmap); return ret; Patches currently in stable-queue which might be from rppt@linux.vnet.ibm.com are queue-4.12/userfaultfd-non-cooperative-flush-event_wqh-at-release-time.patch queue-4.12/userfaultfd_zeropage-return-enospc-in-case-mm-has-gone.patch queue-4.12/userfaultfd-non-cooperative-notify-about-unmap-of-destination-during-mremap.patch