Fix two device-unregistration lifecycle bugs in devmem TCP bindings and add netdevsim support plus selftests covering both RX and TX device unregistration:
1. net: devmem: unmap dma_buf synchronously on queue uninstall Synchronously unmap and detach binding->attachment under binding->lock when the last RX queue is uninstalled in mp_dmabuf_devmem_uninstall() or closed in net_devmem_unbind_dmabuf(), and unmap unbound RX bindings whose queue failed to restart on NETDEV_UNREGISTER, preventing slab-use-after-free in dma_unmap_sg_attrs() when the binding is freed after dma_dev. 2. net: devmem: detach TX bindings on NETDEV_UNREGISTER Extend net_devmem_dev_unregister() to fully detach and unmap TX bindings when binding->dev unregisters, or clear binding->vdev alone when only a virtual device unregisters while binding->dev lives. 3. netdevsim: support devmem RX and TX bindings Enable PP_FLAG_DMA_MAP | PP_FLAG_ALLOW_UNREADABLE_NETMEM, 64-bit DMA mask on nsim_bus_dev, and NETMEM_TX_DMA on netdevsim so devmem RX/TX bindings can be exercised in software selftests. 4. selftests: net: add devmem RX and TX netdev unregister tests Add devmem_bind_rx_unregister_check and devmem_bind_tx_unregister_check to tools/testing/selftests/net/nl_netdev.py. Cc: Tariq Toukan <[email protected]> Cc: Kaifeng Wang <[email protected]> Cc: Dragos Tatulea <[email protected]> --- v4: - 1/4: Unmap RX bindings in net_devmem_unbind_dmabuf() once their queues are closed, and make netif_mp_close_rxq() report queue restart failures, so the NETDEV_UNREGISTER walk only handles bindings whose queue failed to restart. Drop net_devmem_lock: walk the bindings under the xarray lock and take the instance lock of binding->dev in the final free. (Stanislav) Record a queue in bound_rxqs before opening it. (Sashiko) - 2/4: Detach and unmap TX bindings directly from the walk, without a grace period or a second pass. (Stanislav) - Link to v3: https://lore.kernel.org/netdev/[email protected]/ v3: - 1/4: Run the NETDEV_UNREGISTER walk under the netdev instance lock, and skip it when the device only moves to another netns. (Sashiko) - 2/4: Detach all matching TX bindings, then synchronize_net() once before unmapping them. (Sashiko) - 3/4: Only request page pool DMA mapping with CONFIG_HAS_DMA, refuse pp_hold on memory provider pools, and drop unreadable skbs in the software PSP checksum path. (Sashiko) - 4/4: Check only the test's dma-buf in debugfs, skip instead of passing silently, clean up on errors, compute UDMABUF_CREATE per arch, and add the needed config options. (Sashiko, Dragos) - Link to v2: https://lore.kernel.org/netdev/[email protected]/ v2: - 1/4: Don't unmap when a leased queue is unleased. Keep bindings in net_devmem_dmabuf_bindings until freed, hidden from TX lookups by an xarray mark, and unmap unbound RX bindings on NETDEV_UNREGISTER. Update the binding->lock and binding->ref comments. (Sashiko) - 2/4: Detach TX bindings from the same net_devmem_lock-protected walk, which now also covers unbound TX bindings, and clear the LIVE mark instead of erasing the ID. The walk no longer uses RCU or takes binding references (Stanislav). - Link to v1: https://lore.kernel.org/netdev/[email protected]/ Mina Almasry (4): net: devmem: unmap dma_buf synchronously on queue uninstall net: devmem: detach TX bindings on NETDEV_UNREGISTER netdevsim: support devmem RX and TX bindings selftests: net: add devmem RX and TX netdev unregister tests drivers/net/netdevsim/bus.c | 1 + drivers/net/netdevsim/netdev.c | 27 +++- drivers/net/netdevsim/psp.c | 5 + include/net/page_pool/memory_provider.h | 4 +- net/core/devmem.c | 157 +++++++++++++++++++---- net/core/devmem.h | 11 +- net/core/netdev-genl.c | 1 + net/core/netdev_rx_queue.c | 26 ++-- tools/testing/selftests/net/config | 4 + tools/testing/selftests/net/nl_netdev.py | 125 +++++++++++++++++- 10 files changed, 314 insertions(+), 47 deletions(-) base-commit: aa07285705f8d5bac464eb1c5b7412f8e88b91e1 -- 2.56.0.176.g3575e65682-goog
