On Thu, Jul 4, 2019 at 2:06 PM <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > The patch titled > Subject: mm/z3fold.c: lock z3fold page before __SetPageMovable() > has been added to the -mm tree. Its filename is > mm-z3foldc-lock-z3fold-page-before-__setpagemovable.patch > > This patch should soon appear at > http://ozlabs.org/~akpm/mmots/broken-out/mm-z3foldc-lock-z3fold-page-before-__setpagemovable.patch > and later at > http://ozlabs.org/~akpm/mmotm/broken-out/mm-z3foldc-lock-z3fold-page-before-__setpagemovable.patch > > 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 and is updated > there every 3-4 working days > > ------------------------------------------------------ > From: Henry Burns <henryburns@xxxxxxxxxx> > Subject: mm/z3fold.c: lock z3fold page before __SetPageMovable() > > Following zsmalloc.c's example we call trylock_page() and unlock_page(). > Also make z3fold_page_migrate() assert that newpage is passed in locked, > as per the documentation. > > Link: http://lkml.kernel.org/r/20190702005122.41036-1-henryburns@xxxxxxxxxx > Link: http://lkml.kernel.org/r/20190702233538.52793-1-henryburns@xxxxxxxxxx > Signed-off-by: Henry Burns <henryburns@xxxxxxxxxx> > Suggested-by: Vitaly Wool <vitalywool@xxxxxxxxx> > Acked-by: Vitaly Wool <vitalywool@xxxxxxxxx> > Acked-by: David Rientjes <rientjes@xxxxxxxxxx> > Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> > Cc: Vitaly Vul <vitaly.vul@xxxxxxxx> > Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> > Cc: Xidong Wang <wangxidong_97@xxxxxxx> > Cc: Jonathan Adams <jwadams@xxxxxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > --- > > mm/z3fold.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > --- a/mm/z3fold.c~mm-z3foldc-lock-z3fold-page-before-__setpagemovable > +++ a/mm/z3fold.c > @@ -924,7 +924,16 @@ retry: > set_bit(PAGE_HEADLESS, &page->private); > goto headless; > } > - __SetPageMovable(page, pool->inode->i_mapping); > + if (can_sleep) { > + lock_page(page); > + __SetPageMovable(page, pool->inode->i_mapping); > + unlock_page(page); > + } else { > + if (!trylock_page(page)) { Oops, the above should be just trylock_page() without the '!'. Andrew, can you please fix this in-place or do you want a new version to be posted. > + __SetPageMovable(page, pool->inode->i_mapping); > + unlock_page(page); > + } > + } > z3fold_page_lock(zhdr); > > found: > @@ -1331,6 +1340,7 @@ static int z3fold_page_migrate(struct ad > > VM_BUG_ON_PAGE(!PageMovable(page), page); > VM_BUG_ON_PAGE(!PageIsolated(page), page); > + VM_BUG_ON_PAGE(!PageLocked(newpage), newpage); > > zhdr = page_address(page); > pool = zhdr_to_pool(zhdr); > _ > > Patches currently in -mm which might be from henryburns@xxxxxxxxxx are > > mm-z3foldc-lock-z3fold-page-before-__setpagemovable.patch > mm-z3fold-fix-z3fold_buddy_slots-use-after-free.patch >
