Re: [alsa-devel] inconsistent reference counting for snd-soc-skl
On Thu, Oct 13, 2016 at 10:19:37PM +0900, Takashi Sakamoto wrote:
Hi,
I find an issue of snd-soc-skl due to inconsistent reference counting. See this call graph.
skl_probe() ->skl_first_init() ->skl_i915_init() ->snd_hdac_display_power() (CONFIG_SND_SOC_HDAC_HDMI is enabled) ->bus->i915_power_refcount++ ->all error pathes ->skl_free() ->snd_hda_i915_exit() ->WARN_ON(!bus->i915_power_refcount)
This might be also hit by rmmod(8). I see this bug in kernel 4.8 and pre-4.9.
Thanks Takashi for reporting. We will fix this.
Regards, Subhransu
Regards
Takashi Sakamoto
--
Hi,
On Oct 13 2016 22:41, Subhransu S. Prusty wrote:
On Thu, Oct 13, 2016 at 10:19:37PM +0900, Takashi Sakamoto wrote:
Hi,
I find an issue of snd-soc-skl due to inconsistent reference counting. See this call graph.
skl_probe() ->skl_first_init() ->skl_i915_init() ->snd_hdac_display_power() (CONFIG_SND_SOC_HDAC_HDMI is enabled) ->bus->i915_power_refcount++ ->all error pathes ->skl_free() ->snd_hda_i915_exit() ->WARN_ON(!bus->i915_power_refcount)
This might be also hit by rmmod(8). I see this bug in kernel 4.8 and pre-4.9.
Thanks Takashi for reporting. We will fix this.
Thanks for the quick reply.
I'd like to correct the explanation. In last half of skl_probe(), the reference count is decremented. http://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/tree/sound/soc/i...
So this issue may occur on error paths between call of skl_first_init() and the part.
Takashi Sakamoto
participants (2)
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Subhransu S. Prusty -
Takashi Sakamoto