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author | Jon Paul Maloy <jon.maloy@ericsson.com> | 2017-05-11 20:28:15 +0200 |
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committer | David S. Miller <davem@davemloft.net> | 2017-05-11 22:19:30 -0400 |
commit | 844cf763fba654436d3a4279b6a672c196cf1901 (patch) | |
tree | 60dc21eb9e82310b9267805b12f88fa07ae9f925 /tools | |
parent | ad990dbe6d3ac3af1f5f4484b1126b9fc601e98a (diff) |
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 365ad353c256 ("tipc: reduce risk of user starvation during link congestion")
Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'tools')
0 files changed, 0 insertions, 0 deletions