Re: [PATCH] drm/i915: Don't leak command parser tables on suspend/resume

Daniel Vetter
2014-09-23T11:26:07Z

On Tue, Sep 23, 2014 at 10:14:33AM +0100, Chris Wilson wrote:
> On Tue, Sep 23, 2014 at 10:34:46AM +0200, Daniel Vetter wrote:
> > On Mon, Sep 22, 2014 at 08:25:21AM -0700, bradley.d.volkin@intel.com wrote:
> > > From: Brad Volkin <bradley.d.volkin@intel.com>
> > >
> > > Ring init and cleanup are not balanced because we re-init the rings on
> > > resume without having cleaned them up on suspend. This leads to the
> > > driver leaking the parser's hash tables with a kmemleak signature such
> > > as this:
> > >
> > > unreferenced object 0xffff880405960980 (size 32):
> > > comm "systemd-udevd", pid 516, jiffies 4294896961 (age 10202.044s)
> > > hex dump (first 32 bytes):
> > > d0 85 46 c0 ff ff ff ff 00 00 00 00 00 00 00 00 ..F.............
> > > 98 60 28 04 04 88 ff ff 00 00 00 00 00 00 00 00 .`(.............
> > > backtrace:
> > > [<ffffffff81816f9e>] kmemleak_alloc+0x4e/0xb0
> > > [<ffffffff811fa678>] kmem_cache_alloc_trace+0x168/0x2f0
> > > [<ffffffffc03e20a5>] i915_cmd_parser_init_ring+0x2a5/0x3e0 [i915]
> > > [<ffffffffc04088a2>] intel_init_ring_buffer+0x202/0x470 [i915]
> > > [<ffffffffc040c998>] intel_init_vebox_ring_buffer+0x1e8/0x2b0 [i915]
> > > [<ffffffffc03eff59>] i915_gem_init_hw+0x2f9/0x3a0 [i915]
> > > [<ffffffffc03f0057>] i915_gem_init+0x57/0x1d0 [i915]
> > > [<ffffffffc045e26a>] i915_driver_load+0xc0a/0x10e0 [i915]
> > > [<ffffffffc02e0d5d>] drm_dev_register+0xad/0x100 [drm]
> > > [<ffffffffc02e3b9f>] drm_get_pci_dev+0x8f/0x200 [drm]
> > > [<ffffffffc03c934b>] i915_pci_probe+0x3b/0x60 [i915]
> > > [<ffffffff81436725>] local_pci_probe+0x45/0xa0
> > > [<ffffffff81437a69>] pci_device_probe+0xd9/0x130
> > > [<ffffffff81524f4d>] driver_probe_device+0x12d/0x3e0
> > > [<ffffffff815252d3>] __driver_attach+0x93/0xa0
> > > [<ffffffff81522e1b>] bus_for_each_dev+0x6b/0xb0
> > >
> > > This patch extends the current convention of checking whether a
> > > resource is already allocated before allocating it during ring init.
> > > Longer term it might make sense to only init the rings once.
> > >
> > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83794
> > > Signed-off-by: Brad Volkin <bradley.d.volkin@intel.com>
> >
> > We should finally get around to split the ring init code properly into
> > software init in _init functions (done once) and _init_hw functions for
> > rpm/resume ... Anyway, this looks sane.
>
> Maybe someone already sent patches to do so.

Hm, I've thought I've merge the ones that avoid the re-init, but those
didn't go the full path to split the init code. Which ones am I still
missing?
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch