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Oliver Hartkopp
511e64e13d
As reported by Sebastian Andrzej Siewior the use of local_bh_disable()
is only feasible in uni processor systems to update the modification rules.
The usual use-case to update the modification rules is to update the data
of the modifications but not the modification types (AND/OR/XOR/SET) or
the checksum functions itself.
To omit additional memory allocations to maintain fast modification
switching times, the modification description space is doubled at gw-job
creation time so that only the reference to the active modification
description is changed under rcu protection.
Rename cgw_job::mod to cf_mod and make it a RCU pointer. Allocate in
cgw_create_job() and free it together with cgw_job in
cgw_job_free_rcu(). Update all users to dereference cgw_job::cf_mod with
a RCU accessor and if possible once.
[bigeasy: Replace mod1/mod2 from the Oliver's original patch with dynamic
allocation, use RCU annotation and accessor]
Reported-by: Sebastian Andrzej Siewior <[email protected]>
Closes: https://lore.kernel.org/linux-can/[email protected]/
Fixes: dd895d7f21 ("can: cangw: introduce optional uid to reference created routing jobs")
Tested-by: Oliver Hartkopp <[email protected]>
Signed-off-by: Oliver Hartkopp <[email protected]>
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>