From: Jason Gunthorpe <jgg@ziepe.ca>
To: Jann Horn <jannh@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
"Eric W . Biederman" <ebiederm@xmission.com>,
Michel Lespinasse <walken@google.com>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Sakari Ailus <sakari.ailus@linux.intel.com>
Subject: Re: [PATCH 4/4] mm/gup: Assert that the mmap lock is held in __get_user_pages()
Date: Wed, 30 Sep 2020 09:32:17 -0300 [thread overview]
Message-ID: <20200930123217.GD9916@ziepe.ca> (raw)
In-Reply-To: <CAG48ez1GM==OnHpS=ghqZNJPn02FCDUEHc7GQmGRMXUD_aKudg@mail.gmail.com>
On Tue, Sep 29, 2020 at 06:20:01PM -0700, Jann Horn wrote:
> After having cleaned up all GUP callers (except for the atomisp staging
> driver, which currently gets mmap locking completely wrong [1]) to always
> ensure that they hold the mmap lock when calling into GUP (unless the mm is
> not yet globally visible), add an assertion to make sure it stays that way
> going forward.
>
> [1] https://lore.kernel.org/lkml/CAG48ez3tZAb9JVhw4T5e-i=h2_DUZxfNRTDsagSRCVazNXx5qA@mail.gmail.com/
>
> Signed-off-by: Jann Horn <jannh@google.com>
> ---
> mm/gup.c | 2 ++
> 1 file changed, 2 insertions(+)
I'm happy to see this, I have observed many cases of missing locking
here.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Thanks,
Jason
next prev parent reply other threads:[~2020-09-30 12:32 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200930011944.19869-1-jannh@google.com>
2020-09-30 1:20 ` [PATCH 2/4] binfmt_elf: Take the mmap lock around find_extend_vma() Jann Horn
2020-09-30 23:22 ` Michel Lespinasse
2020-09-30 1:20 ` [PATCH 3/4] mmap locking API: Don't check locking if the mm isn't live yet Jann Horn
2020-09-30 12:30 ` Jason Gunthorpe
2020-09-30 12:50 ` Jann Horn
2020-09-30 20:14 ` Jann Horn
2020-09-30 23:26 ` Jason Gunthorpe
2020-09-30 23:51 ` Jann Horn
2020-10-01 19:15 ` Jason Gunthorpe
2020-10-01 20:16 ` Jann Horn
2020-10-01 23:41 ` Jason Gunthorpe
2020-10-01 23:55 ` Jann Horn
2020-09-30 23:42 ` Michel Lespinasse
2020-09-30 1:20 ` [PATCH 4/4] mm/gup: Assert that the mmap lock is held in __get_user_pages() Jann Horn
2020-09-30 12:32 ` Jason Gunthorpe [this message]
2020-09-30 23:24 ` Michel Lespinasse
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