Bug 220240 - sys/dev/xl/if_xl.c: A possible sleep-under-mutex bug in xl_list_rx_init
Summary: sys/dev/xl/if_xl.c: A possible sleep-under-mutex bug in xl_list_rx_init
Status: New
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: CURRENT
Hardware: Any Any
: --- Affects Only Me
Assignee: freebsd-bugs (Nobody)
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-06-24 03:21 UTC by Jia-Ju Bai
Modified: 2017-06-24 03:22 UTC (History)
1 user (show)

See Also:

Attachments
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Jia-Ju Bai 2017-06-24 03:21:48 UTC 
The driver may sleep under a mutex, and the function call path is:
xl_resume [acquire the mutex]
  xl_init_locked
    xl_list_rx_init
      bus_dmamap_create(BUS_DMA_WAITOK) --> may sleep

The possible fix of this bug is to replace the "BUS_DMA_WAITOK" in bus_dmamap_create with "BUS_DMA_NOWAIT".

This bug is found by a static analysis tool written by myself, and it is checked by my review of the FreeBSD code.