| Message ID | 20231215171020.687342-22-bigeasy@linutronix.de (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | locking: Introduce nested-BH locking. | expand |
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index 29aac327574d6..9c7aacd73b590 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -2263,6 +2263,8 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq, len = xdp->data_end - xdp->data_hard_start - pp->rx_offset_correction; data_len = xdp->data_end - xdp->data; + + guard(local_lock_nested_bh)(&bpf_run_lock.redirect_lock); act = bpf_prog_run_xdp(prog, xdp); /* Due xdp_adjust_tail: DMA sync for_device cover max len CPU touch */ diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index 93137606869e2..3a5524ffaba68 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -3793,6 +3793,7 @@ mvpp2_run_xdp(struct mvpp2_port *port, struct bpf_prog *prog, u32 ret, act; len = xdp->data_end - xdp->data_hard_start - MVPP2_SKB_HEADROOM; + guard(local_lock_nested_bh)(&bpf_run_lock.redirect_lock); act = bpf_prog_run_xdp(prog, xdp); /* Due xdp_adjust_tail: DMA sync for_device cover max len CPU touch */ diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c index 4d519ea833b2c..e48e84d6159bc 100644 --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c @@ -1422,6 +1422,7 @@ static bool otx2_xdp_rcv_pkt_handler(struct otx2_nic *pfvf, xdp_prepare_buff(&xdp, hard_start, data - hard_start, cqe->sg.seg_size, false); + guard(local_lock_nested_bh)(&bpf_run_lock.redirect_lock); act = bpf_prog_run_xdp(prog, &xdp); switch (act) {
The per-CPU variables used during bpf_prog_run_xdp() invocation and later during xdp_do_redirect() rely on disabled BH for their protection. Without locking in local_bh_disable() on PREEMPT_RT these data structure require explicit locking. This is a follow-up on the previous change which introduced bpf_run_lock.redirect_lock and uses it now within drivers. The simple way is to acquire the lock before bpf_prog_run_xdp() is invoked and hold it until the end of function. This does not always work because some drivers (cpsw, atlantic) invoke xdp_do_flush() in the same context. Acquiring the lock in bpf_prog_run_xdp() and dropping in xdp_do_redirect() (without touching drivers) does not work because not all driver, which use bpf_prog_run_xdp(), do support XDP_REDIRECT (and invoke xdp_do_redirect()). Ideally the minimal locking scope would be bpf_prog_run_xdp() + xdp_do_redirect() and everything else (error recovery, DMA unmapping, free/ alloc of memory, …) would happen outside of the locked section. Cc: Alexei Starovoitov <ast@kernel.org> Cc: Geetha sowjanya <gakula@marvell.com> Cc: Jesper Dangaard Brouer <hawk@kernel.org> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Marcin Wojtas <mw@semihalf.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Subbaraya Sundeep <sbhatta@marvell.com> Cc: Sunil Goutham <sgoutham@marvell.com> Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Cc: hariprasad <hkelam@marvell.com> Cc: bpf@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- drivers/net/ethernet/marvell/mvneta.c | 2 ++ drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 1 + drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c | 1 + 3 files changed, 4 insertions(+)