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| author | Olivier Langlois <olivier@trillion01.com> | 2024-10-13 20:28:24 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-11-06 21:55:38 +0100 |
| commit | 2f3cc8e441c9f657ff036c56baaab7dddbd0b350 (patch) | |
| tree | 7a0388250c5486aeb3369af65bac9a8bc8eec712 /io_uring/napi.c | |
| parent | io_uring: prevent speculating sq_array indexing (diff) | |
| download | linux-2f3cc8e441c9f657ff036c56baaab7dddbd0b350.tar.xz linux-2f3cc8e441c9f657ff036c56baaab7dddbd0b350.zip | |
io_uring/napi: protect concurrent io_napi_entry timeout accesses
io_napi_entry timeout value can be updated while accessed from the poll
functions.
Its concurrent accesses are wrapped with READ_ONCE()/WRITE_ONCE() macros
to avoid incorrect compiler optimizations.
Signed-off-by: Olivier Langlois <olivier@trillion01.com>
Link: https://lore.kernel.org/r/3de3087563cf98f75266fd9f85fdba063a8720db.1728828877.git.olivier@trillion01.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring/napi.c')
| -rw-r--r-- | io_uring/napi.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/io_uring/napi.c b/io_uring/napi.c index d0cf694d0172..dda2e083fb5d 100644 --- a/io_uring/napi.c +++ b/io_uring/napi.c @@ -60,7 +60,7 @@ void __io_napi_add(struct io_ring_ctx *ctx, struct socket *sock) rcu_read_lock(); e = io_napi_hash_find(hash_list, napi_id); if (e) { - e->timeout = jiffies + NAPI_TIMEOUT; + WRITE_ONCE(e->timeout, jiffies + NAPI_TIMEOUT); rcu_read_unlock(); return; } @@ -92,7 +92,7 @@ static void __io_napi_remove_stale(struct io_ring_ctx *ctx) spin_lock(&ctx->napi_lock); hash_for_each(ctx->napi_ht, i, e, node) { - if (time_after(jiffies, e->timeout)) { + if (time_after(jiffies, READ_ONCE(e->timeout))) { list_del(&e->list); hash_del_rcu(&e->node); kfree_rcu(e, rcu); @@ -150,7 +150,7 @@ static bool __io_napi_do_busy_loop(struct io_ring_ctx *ctx, napi_busy_loop_rcu(e->napi_id, loop_end, loop_end_arg, ctx->napi_prefer_busy_poll, BUSY_POLL_BUDGET); - if (time_after(jiffies, e->timeout)) + if (time_after(jiffies, READ_ONCE(e->timeout))) is_stale = true; } |