On Sat, 1 Sep 2018, Jia-Ju Bai wrote: > The driver may sleep with holding a spinlock. > > The function call paths (from bottom to top) in Linux-4.16 are: > > [FUNC] hid_alloc_report_buf(GFP_KERNEL) > drivers/hid/hid-core.c, 1435: > hid_alloc_report_buf in __hid_request > ./include/linux/hid.h, 1023: > __hid_request in hid_hw_request > drivers/hid/hid-picolcd_core.c, 111: > hid_hw_request in picolcd_send_and_wait > drivers/hid/hid-picolcd_core.c, 100: > _raw_spin_lock_irqsave in picolcd_send_and_wait > > [FUNC] hid_alloc_report_buf(GFP_KERNEL) > drivers/hid/hid-core.c, 1435: > hid_alloc_report_buf in __hid_request > ./include/linux/hid.h, 1023: > __hid_request in hid_hw_request > drivers/hid/hid-picolcd_core.c, 245: > hid_hw_request in picolcd_reset > drivers/hid/hid-picolcd_core.c, 235: > _raw_spin_lock_irqsave in picolcd_reset > > [FUNC] hid_alloc_report_buf(GFP_KERNEL) > drivers/hid/hid-core.c, 1435: > hid_alloc_report_buf in __hid_request > ./include/linux/hid.h, 1023: > __hid_request in hid_hw_request > drivers/hid/hid-picolcd_fb.c, 215: > hid_hw_request in picolcd_fb_reset > drivers/hid/hid-picolcd_fb.c, 206: > _raw_spin_lock_irqsave in picolcd_fb_reset > > [FUNC] hid_alloc_report_buf(GFP_KERNEL) > drivers/hid/hid-core.c, 1435: > hid_alloc_report_buf in __hid_request > ./include/linux/hid.h, 1023: > __hid_request in hid_hw_request > drivers/hid/hid-lg4ff.c, 465: > hid_hw_request in lg4ff_play > drivers/hid/hid-lg4ff.c, 441: > _raw_spin_lock_irqsave in lg4ff_play > > To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC. > > This bug is found by my static analysis tool DSAC. Could you please rewrite the changelog so that it's human readable? The above is a bit hard to understand, I think something along the lines of "__hid_request() has to be allocating with GFP_ATOMIC because there are the following callchains leading to __hid_request() being an atomic context: ... a->b->c.._hid_request()" etc. Thanks, -- Jiri Kosina SUSE Labs
