• Alexander Strakh's avatar
    Driver scsi_lib.c might sleep in atomic context, because it calls · 2fd4f4cb
    Alexander Strakh authored
    scsi_device_put under spin_lock_irqsave.
    
    drivers/scsi/scsi_lib.c:356:
    	spin_lock_irqsave(shost->host_lock, flags);
    	scsi_device_put(sdev);
    Path to might_sleep macro from scsi_device_put:
    1. scsi_device_put calls put_device at ./drivers/scsi/scsi.c:1111
    2. put_device calls kobject_put at ./drivers/base/core.c:1038
    3. kobject_put calls kref_put at ./lib/kobject.c
    4. kref_put may call callback function kobject_release at ./lib/kref.c if
    refcount becomes zero, which might_sleep because it calls user event. Details:
    	4.1 kobject_cleanup calls kobject_uevent at ./lib/kobject.c:555
    	4.2 kobject_uevent calls kobject_uevent_env at  ./lib/kobject_uevent.c:282
    	4.3 kobject_uevent_env calls call_usermodehelper_exec at
    ./include/linux/kmod.h:83
    	4.4 call_usermodehelper_exec calls wait_for_completion at
    ./kernel/kmod.c:481
    	4.5 wait_for_completion calls wait_for_common at ./kernel/sched.c:5710
    	4.5 wait_for_common calls might_sleep at ./kernels/sched.c:5692
    
    Found by Linux Driver Verification project.
    
    Delete wrong sleeping function calls.
    Signed-off-by: default avatarAlexander Strakh <strakh@ispras.ru>
    Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
    Cc: Jens Axboe <jens.axboe@oracle.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    2fd4f4cb
scsi_lib.c 64.1 KB