Messages in this thread | | | From | Krzysztof Kozlowski <> | Date | Thu, 14 Dec 2017 11:11:07 +0100 | Subject | Re: [BUG] sound/soc/samsung: a possible sleep-in-atomic bugs in s3c_pcm_hw_params |
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On Tue, Dec 12, 2017 at 2:24 AM, Jia-Ju Bai <baijiaju1990@163.com> wrote: > According to sound/soc/samsung/pcm.c, the kernel module may sleep under a > spinlock. > The function call path is: > s3c_pcm_hw_params (acquire the spinlock) > clk_get_rate > clk_core_get_rate > clk_prepare_lock > mutex_lock --> may sleep > > I do not find a good way to fix it, so I only report. > This possible bug is found by my static analysis tool (DSAC) and my code > review.
Thanks for the report. Your finding looks correct, the code might sleep under spinlock.
I do not see easy solution. Maybe the readl(regs + S3C_PCM_CLKCTL) and clk_get_rate() could be moved before spinlock. The second path modifying it - s3c_pcm_set_sysclk() - is not protected by it. The spinlock is not effective around it.
Best regards, Krzysztof
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