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author | Toke Høiland-Jørgensen <toke@redhat.com> | 2021-06-24 18:06:09 +0200 |
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committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-06-24 19:46:39 +0200 |
commit | 0cc84b9a6003fa7f6ef5d19e7c8532a01cd41776 (patch) | |
tree | 64460f00c0ded7b3f5141814faedc5c14ba7f63f /README | |
parent | 2f1e432d339c5fed435adf521cae392755721050 (diff) | |
download | linux-0cc84b9a6003fa7f6ef5d19e7c8532a01cd41776.tar.bz2 |
ti: Remove rcu_read_lock() around XDP program invocation
The cpsw driver has rcu_read_lock()/rcu_read_unlock() pairs around XDP
program invocations. However, the actual lifetime of the objects referred
by the XDP program invocation is longer, all the way through to the call to
xdp_do_flush(), making the scope of the rcu_read_lock() too small. This
turns out to be harmless because it all happens in a single NAPI poll
cycle (and thus under local_bh_disable()), but it makes the rcu_read_lock()
misleading.
Rather than extend the scope of the rcu_read_lock(), just get rid of it
entirely. With the addition of RCU annotations to the XDP_REDIRECT map
types that take bh execution into account, lockdep even understands this to
be safe, so there's really no reason to keep it around.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: linux-omap@vger.kernel.org
Link: https://lore.kernel.org/bpf/20210624160609.292325-20-toke@redhat.com
Diffstat (limited to 'README')
0 files changed, 0 insertions, 0 deletions