From: Linus Torvalds <torvalds@linux-foundation.org>
To: Uladzislau Rezki <urezki@gmail.com>
Cc: Waiman Long <longman@redhat.com>, Joe Perches <joe@perches.com>,
Andrew Morton <akpm@linux-foundation.org>,
David Howells <dhowells@redhat.com>,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
Linux-MM <linux-mm@kvack.org>,
keyrings@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Matthew Wilcox <willy@infradead.org>,
David Rientjes <rientjes@google.com>
Subject: Re: [PATCH v3] mm: Add kvfree_sensitive() for freeing sensitive data objects
Date: Tue, 7 Apr 2020 14:30:56 -0700 [thread overview]
Message-ID: <CAHk-=whrZLs=+VkBXS_KWrMwoM2PRmw6mKEPJHRBQ_e3raFh9Q@mail.gmail.com> (raw)
In-Reply-To: <20200407212447.GA29554@pc636>
On Tue, Apr 7, 2020 at 2:25 PM Uladzislau Rezki <urezki@gmail.com> wrote:
>
> Seems like there is only one place where we can "sleep". I mean when we
> call vfree(). That is free_vmap_area_noflush() -> try_purge_vmap_area_lazy().
> Basically try_purge_vmap_area_lazy() can call the schedule() what is not
> allowed for IRQs. Instead of inlining the try_purge_vmap_area_lazy()
> into current context we can schedule_work(). And i think it makes sense
> from many point of views.
I don't think that's the only case.
Or rather, that may be the only case of _sleeping_, but we also aren't
irq-safe wrt locking.
And I'm not just talking about the vmap_purge_lock mutex, but all the
spinlocks etc we have.
That said, I haven't looked at that code in _ages_. Maybe those things
would be trivial to just turn into irq-safe ones and there are no real
latency issues anywhere.
Linus
next prev parent reply other threads:[~2020-04-07 21:31 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-07 20:03 Waiman Long
2020-04-07 20:09 ` Linus Torvalds
2020-04-07 20:19 ` David Howells
2020-04-07 20:24 ` Waiman Long
2020-04-07 20:21 ` David Howells
2020-05-05 20:35 ` Andrew Morton
2020-05-06 1:29 ` Waiman Long
2020-04-07 20:31 ` Joe Perches
2020-04-07 20:45 ` Waiman Long
2020-04-07 21:01 ` Linus Torvalds
2020-04-07 21:24 ` Uladzislau Rezki
2020-04-07 21:30 ` Linus Torvalds [this message]
2020-04-07 22:12 ` Matthew Wilcox
2020-04-08 0:35 ` Joe Perches
2020-04-08 13:38 ` Jarkko Sakkinen
2020-05-01 23:22 ` Eric Biggers
2020-05-04 2:57 ` Waiman Long
2020-05-14 11:00 ` Balbir Singh
2020-05-14 12:00 ` Matthew Wilcox
2020-05-14 12:08 ` Joe Perches
2020-05-17 0:27 ` Balbir Singh
2020-05-17 0:44 ` Matthew Wilcox
2020-05-18 2:39 ` Waiman Long
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