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iflib: initialize LRO unconditionally

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Changes to the LRO code have exposed a bug in iflib where devices
which are not capable of doing LRO are still calling
tcp_lro_flush_all(), even when they have not initialized the LRO
context. This used to be mostly harmless, but the LRO code now sets
the VNET based on the ifp in the lro context and will try to access it
through a NULL ifp resulting in a panic at boot.

To fix this, we unconditionally initializes LRO so that we have a
valid LRO context when calling tcp_lro_flush_all(). One alternative is
to check the device capabilities before calling tcp_lro_flush_all() or
adding a new state flag in the ctx. However, it seems unwise to add an
extra, mostly useless test for higher performance devices when we can
just initialize LRO for all devices.

Reviewed by: erj, hselasky, markj, olivier
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D29928
This commit is contained in:
Andrew Gallatin 2021-04-23 05:51:22 -04:00
parent 5f00292fe3
commit 3183d0b680
1 changed files with 9 additions and 13 deletions
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22
sys/net/iflib.c
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@ -5891,15 +5891,13 @@ iflib_rx_structures_setup(if_ctx_t ctx)
for (q = 0; q < ctx->ifc_softc_ctx.isc_nrxqsets; q++, rxq++) {
#if defined(INET6) || defined(INET)
if (if_getcapabilities(ctx->ifc_ifp) & IFCAP_LRO) {
err = tcp_lro_init_args(&rxq->ifr_lc, ctx->ifc_ifp,
TCP_LRO_ENTRIES, min(1024,
ctx->ifc_softc_ctx.isc_nrxd[rxq->ifr_fl_offset]));
if (err != 0) {
device_printf(ctx->ifc_dev,
"LRO Initialization failed!\n");
goto fail;
}
err = tcp_lro_init_args(&rxq->ifr_lc, ctx->ifc_ifp,
TCP_LRO_ENTRIES, min(1024,
ctx->ifc_softc_ctx.isc_nrxd[rxq->ifr_fl_offset]));
if (err != 0) {
device_printf(ctx->ifc_dev,
"LRO Initialization failed!\n");
goto fail;
}
#endif
IFDI_RXQ_SETUP(ctx, rxq->ifr_id);
@ -5914,8 +5912,7 @@ fail:
*/
rxq = ctx->ifc_rxqs;
for (i = 0; i < q; ++i, rxq++) {
if (if_getcapabilities(ctx->ifc_ifp) & IFCAP_LRO)
tcp_lro_free(&rxq->ifr_lc);
tcp_lro_free(&rxq->ifr_lc);
}
return (err);
#endif
@ -5938,8 +5935,7 @@ iflib_rx_structures_free(if_ctx_t ctx)
iflib_dma_free(&rxq->ifr_ifdi[j]);
iflib_rx_sds_free(rxq);
#if defined(INET6) || defined(INET)
if (if_getcapabilities(ctx->ifc_ifp) & IFCAP_LRO)
tcp_lro_free(&rxq->ifr_lc);
tcp_lro_free(&rxq->ifr_lc);
#endif
}
free(ctx->ifc_rxqs, M_IFLIB);