lkml.org 
[lkml]   [2021]   [Jan]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC PATCH v3 1/8] Use refcount_t for ucounts reference counting
    On Mon, Jan 18, 2021 at 11:14:48AM -0800, Linus Torvalds wrote:
    > On Fri, Jan 15, 2021 at 6:59 AM Alexey Gladkov <gladkov.alexey@gmail.com> wrote:
    > >
    > > @@ -152,10 +153,7 @@ static struct ucounts *get_ucounts(struct user_namespace *ns, kuid_t uid)
    > > ucounts = new;
    > > }
    > > }
    > > - if (ucounts->count == INT_MAX)
    > > - ucounts = NULL;
    > > - else
    > > - ucounts->count += 1;
    > > + refcount_inc(&ucounts->count);
    > > spin_unlock_irq(&ucounts_lock);
    > > return ucounts;
    > > }
    >
    > This is wrong.
    >
    > It used to return NULL when the count saturated.
    >
    > Now it just silently saturates.
    >
    > I'm not sure how many people care, but that NULL return ends up being
    > returned quite widely (through "inc_uncount()" and friends).
    >
    > The fact that this has no commit message at all to explain what it is
    > doing and why is also a grounds for just NAK.

    Sorry about that. I thought that this code is not needed when switching
    from int to refcount_t. I was wrong. I'll think about how best to check
    it.

    --
    Rgrds, legion

    \
     
     \ /
      Last update: 2021-01-18 20:51    [W:2.183 / U:0.024 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site