diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-07-09 09:01:53 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-07-11 16:01:15 -0700 |
| commit | 30dbb2d0e16fce445581049ebcd9043837a843ac (patch) | |
| tree | 771de070ce8e91f1c5a1e7b5773c1e20bc6b5c44 | |
| parent | 0346000aaab8cf8baf4ae40c48a5779a03971e80 (diff) | |
net_sched: act: annotate data-races in tcf_lastuse_update() and tcf_tm_dump()
tcf_tm_dump() reads fields that can be changed concurrently,
and tcf_lastuse_update() might race against itself.
Add READ_ONCE() and WRITE_ONCE() annotations.
Fetch jiffies once in tcf_tm_dump().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250709090204.797558-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/net/act_api.h | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/include/net/act_api.h b/include/net/act_api.h index 04781c92b43d..2894cfff2da3 100644 --- a/include/net/act_api.h +++ b/include/net/act_api.h @@ -76,19 +76,24 @@ static inline void tcf_lastuse_update(struct tcf_t *tm) { unsigned long now = jiffies; - if (tm->lastuse != now) - tm->lastuse = now; - if (unlikely(!tm->firstuse)) - tm->firstuse = now; + if (READ_ONCE(tm->lastuse) != now) + WRITE_ONCE(tm->lastuse, now); + if (unlikely(!READ_ONCE(tm->firstuse))) + WRITE_ONCE(tm->firstuse, now); } static inline void tcf_tm_dump(struct tcf_t *dtm, const struct tcf_t *stm) { - dtm->install = jiffies_to_clock_t(jiffies - stm->install); - dtm->lastuse = jiffies_to_clock_t(jiffies - stm->lastuse); - dtm->firstuse = stm->firstuse ? - jiffies_to_clock_t(jiffies - stm->firstuse) : 0; - dtm->expires = jiffies_to_clock_t(stm->expires); + unsigned long firstuse, now = jiffies; + + dtm->install = jiffies_to_clock_t(now - READ_ONCE(stm->install)); + dtm->lastuse = jiffies_to_clock_t(now - READ_ONCE(stm->lastuse)); + + firstuse = READ_ONCE(stm->firstuse); + dtm->firstuse = firstuse ? + jiffies_to_clock_t(now - firstuse) : 0; + + dtm->expires = jiffies_to_clock_t(READ_ONCE(stm->expires)); } static inline enum flow_action_hw_stats tc_act_hw_stats(u8 hw_stats) |