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netmap: fix LOR in iflib_netmap_register

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In iflib_device_register(), the CTX_LOCK is acquired first and then
IFNET_WLOCK is acquired by ether_ifattach(). However, in netmap_hw_reg()
we do the opposite: IFNET_RLOCK is acquired first, and then CTX_LOCK
is acquired by iflib_netmap_register(). Fix this LOR issue by wrapping
the CTX_LOCK/UNLOCK calls in iflib_device_register with an additional
IFNET_WLOCK. This is safe since the IFNET_WLOCK is recursive.

MFC after:	1 month
This commit is contained in:
Vincenzo Maffione 2022-01-14 21:09:04 +00:00
parent 9f0b56872c
commit e0e1240528
1 changed files with 3 additions and 0 deletions
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3
sys/net/iflib.c
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@ -5057,6 +5057,7 @@ iflib_device_register(device_t dev, void *sc, if_shared_ctx_t sctx, if_ctx_t *ct
ifp = ctx->ifc_ifp;
iflib_reset_qvalues(ctx);
IFNET_WLOCK();
CTX_LOCK(ctx);
if ((err = IFDI_ATTACH_PRE(ctx)) != 0) {
device_printf(dev, "IFDI_ATTACH_PRE failed %d\n", err);
@ -5250,6 +5251,7 @@ iflib_device_register(device_t dev, void *sc, if_shared_ctx_t sctx, if_ctx_t *ct
iflib_add_pfil(ctx);
ctx->ifc_flags |= IFC_INIT_DONE;
CTX_UNLOCK(ctx);
IFNET_WUNLOCK();
return (0);
@ -5265,6 +5267,7 @@ iflib_device_register(device_t dev, void *sc, if_shared_ctx_t sctx, if_ctx_t *ct
iflib_free_intr_mem(ctx);
fail_unlock:
CTX_UNLOCK(ctx);
IFNET_WUNLOCK();
iflib_deregister(ctx);
fail_ctx_free:
device_set_softc(ctx->ifc_dev, NULL);