diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-05-03 16:56:03 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-05-04 16:55:11 -0400 |
| commit | 46cc6e4976e3d9058490f20d93bc7805f7f2d81e (patch) | |
| tree | 5856b8bab06927f7fc934b7f07a272f5ae680d9c /include/linux/u64_stats_sync.h | |
| parent | 5332174a83720921a5ef6db8080a8691f7ccbc27 (diff) | |
tcp: fix lockdep splat in tcp_snd_una_update()
tcp_snd_una_update() and tcp_rcv_nxt_update() call
u64_stats_update_begin() either from process context or BH handler.
This triggers a lockdep splat on 32bit & SMP builds.
We could add u64_stats_update_begin_bh() variant but this would
slow down 32bit builds with useless local_disable_bh() and
local_enable_bh() pairs, since we own the socket lock at this point.
I add sock_owned_by_me() helper to have proper lockdep support
even on 64bit builds, and new u64_stats_update_begin_raw()
and u64_stats_update_end_raw methods.
Fixes: c10d9310edf5 ("tcp: do not assume TCP code is non preemptible")
Reported-by: Fabio Estevam <festevam@gmail.com>
Diagnosed-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/u64_stats_sync.h')
| -rw-r--r-- | include/linux/u64_stats_sync.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/u64_stats_sync.h b/include/linux/u64_stats_sync.h index df89c9bcba7d..d3a2bb712af3 100644 --- a/include/linux/u64_stats_sync.h +++ b/include/linux/u64_stats_sync.h @@ -89,6 +89,20 @@ static inline void u64_stats_update_end(struct u64_stats_sync *syncp) #endif } +static inline void u64_stats_update_begin_raw(struct u64_stats_sync *syncp) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + raw_write_seqcount_begin(&syncp->seq); +#endif +} + +static inline void u64_stats_update_end_raw(struct u64_stats_sync *syncp) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + raw_write_seqcount_end(&syncp->seq); +#endif +} + static inline unsigned int u64_stats_fetch_begin(const struct u64_stats_sync *syncp) { #if BITS_PER_LONG==32 && defined(CONFIG_SMP) |