tipc: make macro tipc_wait_for_cond() smp safe
The macro tipc_wait_for_cond() is embedding the macro sk_wait_event() to fulfil its task. The latter, in turn, is evaluating the stated condition outside the socket lock context. This is problematic if the condition is accessing non-trivial data structures which may be altered by incoming interrupts, as is the case with the cong_links() linked list, used by socket to keep track of the current set of congested links. We sometimes see crashes when this list is accessed by a condition function at the same time as a SOCK_WAKEUP interrupt is removing an element from the list. We fix this by expanding selected parts of sk_wait_event() into the outer macro, while ensuring that all evaluations of a given condition are performed under socket lock protection. Fixes: commit 365ad353 ("tipc: reduce risk of user starvation during link congestion") Reviewed-by:Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by:
Jon Maloy <jon.maloy@ericss...>
parent
ad990dbe
Please register or sign in to comment