Hi David, On Fri, Sep 22, 2023 at 04:00:21PM +0800, David Gow wrote: > On Wed, 20 Sept 2023 at 14:12, Arthur Grillo <arthurgrillo@xxxxxxxxxx> wrote: > > > > On Kunit, if we allocate a resource A and B on this order, with its > > deferred actions to free them. The resource stack would be something > > like this: > > > > +---------+ > > | free(B) | > > +---------+ > > | ... | > > +---------+ > > | free(A) | > > +---------+ > > > > If the deferred action of A accesses B, this would cause a > > use-after-free bug. To solve that, we need a way to change the order > > of actions. > > > > Create a function to move an action to the top of the resource stack, > > as shown in the diagram below. > > > > +---------+ +---------+ > > | free(B) | | free(A) | > > +---------+ +---------+ > > | ... | -> | free(B) | > > +---------+ +---------+ > > | free(A) | | ... | > > +---------+ +---------+ > > > > Signed-off-by: Arthur Grillo <arthurgrillo@xxxxxxxxxx> > > --- > > Thanks. This is a really interesting patch: my hope was that something > like this wouldn't be necessary, as in most cases freeing things in > the reverse order to which they were created is the right thing to do. > > It looks like, from the comments on patch 3, this may no longer be > necessary? Is that so? Yeah, it's no longer necessary Maxime
