From: Kimberly Brown <kimbrow...@gmail.com> Sent: Thursday, March 14, 2019 1:05 PM > > Fix a race condition that can result in a ring buffer pointer being set > to null while a "_show" function is reading the ring buffer's data. This > problem was discussed here: https://lkml.org/lkml/2018/10/18/779 > > To fix the race condition, add a new mutex lock to the > "hv_ring_buffer_info" struct. Add a new function, > "hv_ringbuffer_pre_init()", where a channel's inbound and outbound > ring_buffer_info mutex locks are initialized. > > Acquire/release the locks in the "hv_ringbuffer_cleanup()" function, > which is where the ring buffer pointers are set to null. > > Acquire/release the locks in the four channel-level "_show" functions > that access ring buffer data. Remove the "const" qualifier from the > "vmbus_channel" parameter and the "rbi" variable of the channel-level > "_show" functions so that the locks can be acquired/released in these > functions. > > Acquire/release the locks in hv_ringbuffer_get_debuginfo(). Remove the > "const" qualifier from the "hv_ring_buffer_info" parameter so that the > locks can be acquired/released in this function. > > Signed-off-by: Kimberly Brown <kimbrow...@gmail.com>
Reviewed-by: Michael Kelley <mikel...@microsoft.com>
