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To:     lee.jones@linaro.org
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
From:   Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [BUG] mfd: ezx-pcap: Possible sleep-in-atomic-context bugs in
 pcap_adc_irq()
Message-ID: <f83a444a-1943-6c8c-5cd4-88e2acb17fa6@gmail.com>
Date:   Sat, 15 Sep 2018 16:50:31 +0800
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The driver may sleep in an interrupt handler.
The function call paths (from bottom to top) in Linux-4.17 are:

[FUNC] mutex_lock_nested
drivers/mfd/ezx-pcap.c, 272:
     mutex_lock_nested in pcap_adc_irq (interrupt handler)

[FUNC] mutex_lock_nested
drivers/mfd/ezx-pcap.c, 100:
     mutex_lock_nested in ezx_pcap_read
drivers/mfd/ezx-pcap.c, 281:
     ezx_pcap_read in pcap_adc_irq (interrupt handler)

[FUNC] mutex_lock_nested
drivers/mfd/ezx-pcap.c, 85:
     mutex_lock_nested in ezx_pcap_write
drivers/mfd/ezx-pcap.c, 285:
     ezx_pcap_write in pcap_adc_irq (interrupt handler)

[FUNC] mutex_lock_nested
drivers/mfd/ezx-pcap.c, 244:
     mutex_lock_nested in pcap_adc_trigger
drivers/mfd/ezx-pcap.c, 299:
     pcap_adc_trigger in pcap_adc_irq (interrupt handler)

These bugs are found by my static analysis tool DSAC.


Best wishes,
Jia-Ju Bai