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a949e86c0d
vmbus_process_offer() does two things (among others):
1) first, it sets the channel's target CPU with cpu_hotplug_lock;
2) it then adds the channel to the channel list(s) with channel_mutex.
Since cpu_hotplug_lock is released before (2), the channel's target CPU
(as designated in (1)) can be deemed "free" by hv_synic_cleanup() and go
offline before the channel is added to the list.
Fix the race condition by "extending" the cpu_hotplug_lock critical
section to include (2) (and (1)), nesting the channel_mutex critical
section within the cpu_hotplug_lock critical section as done elsewhere
(hv_synic_cleanup(), target_cpu_store()) in the hyperv drivers code.
Move even further by extending the channel_mutex critical section to
include (1) (and (2)): this change allows to remove (the now redundant)
bind_channel_to_cpu_lock, and generally simplifies the handling of the
target CPUs (that are now always modified with channel_mutex held).
Fixes:
|
||
|---|---|---|
| .. | ||
| channel_mgmt.c | ||
| channel.c | ||
| connection.c | ||
| hv_balloon.c | ||
| hv_debugfs.c | ||
| hv_fcopy.c | ||
| hv_kvp.c | ||
| hv_snapshot.c | ||
| hv_trace_balloon.h | ||
| hv_trace.c | ||
| hv_trace.h | ||
| hv_util.c | ||
| hv_utils_transport.c | ||
| hv_utils_transport.h | ||
| hv.c | ||
| hyperv_vmbus.h | ||
| Kconfig | ||
| Makefile | ||
| ring_buffer.c | ||
| vmbus_drv.c | ||