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author | Paul E. McKenney <paulmck@kernel.org> | 2021-06-24 18:05:51 +0200 |
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committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-06-24 19:41:14 +0200 |
commit | b9964ce74544ea6cbc4eabd2c89a531adf7f291d (patch) | |
tree | 98f9f383bb65b166cf62c54da71080d22aee6023 /Documentation/RCU | |
parent | 0bc919d3e0b8149a60d2444c6a8e2b5974556522 (diff) | |
download | linux-b9964ce74544ea6cbc4eabd2c89a531adf7f291d.tar.bz2 |
rcu: Create an unrcu_pointer() to remove __rcu from a pointer
The xchg() and cmpxchg() functions are sometimes used to carry out RCU
updates. Unfortunately, this can result in sparse warnings for both
the old-value and new-value arguments, as well as for the return value.
The arguments can be dealt with using RCU_INITIALIZER():
old_p = xchg(&p, RCU_INITIALIZER(new_p));
But a sparse warning still remains due to assigning the __rcu pointer
returned from xchg to the (most likely) non-__rcu pointer old_p.
This commit therefore provides an unrcu_pointer() macro that strips
the __rcu. This macro can be used as follows:
old_p = unrcu_pointer(xchg(&p, RCU_INITIALIZER(new_p)));
Reported-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210624160609.292325-2-toke@redhat.com
Diffstat (limited to 'Documentation/RCU')
0 files changed, 0 insertions, 0 deletions