Messages in this thread | | | Date | Thu, 10 Aug 2017 17:23:52 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH 2/2] mm,fork: introduce MADV_WIPEONFORK |
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On Sun 06-08-17 10:04:25, Rik van Riel wrote: [...] > diff --git a/kernel/fork.c b/kernel/fork.c > index 17921b0390b4..db1fb2802ecc 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -659,6 +659,13 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, > tmp->vm_flags &= ~(VM_LOCKED | VM_LOCKONFAULT); > tmp->vm_next = tmp->vm_prev = NULL; > file = tmp->vm_file; > + > + /* With VM_WIPEONFORK, the child gets an empty VMA. */ > + if (tmp->vm_flags & VM_WIPEONFORK) { > + tmp->vm_file = file = NULL; > + tmp->vm_ops = NULL; > + }
What about VM_SHARED/|VM)MAYSHARE flags. Is it OK to keep the around? At least do_anonymous_page SIGBUS on !vm_ops && VM_SHARED. Or do I miss where those flags are cleared?
> + > if (file) { > struct inode *inode = file_inode(file); > struct address_space *mapping = file->f_mapping; -- Michal Hocko SUSE Labs
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