From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- drivers/net/netdevsim/ethtool.c | 280 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 280 insertions(+) create mode 100644 drivers/net/netdevsim/ethtool.c (limited to 'drivers/net/netdevsim/ethtool.c') diff --git a/drivers/net/netdevsim/ethtool.c b/drivers/net/netdevsim/ethtool.c new file mode 100644 index 000000000..025ea7987 --- /dev/null +++ b/drivers/net/netdevsim/ethtool.c @@ -0,0 +1,280 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Facebook + +#include +#include +#include + +#include "netdevsim.h" + +static void +nsim_get_pause_stats(struct net_device *dev, + struct ethtool_pause_stats *pause_stats) +{ + struct netdevsim *ns = netdev_priv(dev); + + if (ns->ethtool.pauseparam.report_stats_rx) + pause_stats->rx_pause_frames = 1; + if (ns->ethtool.pauseparam.report_stats_tx) + pause_stats->tx_pause_frames = 2; +} + +static void +nsim_get_pauseparam(struct net_device *dev, struct ethtool_pauseparam *pause) +{ + struct netdevsim *ns = netdev_priv(dev); + + pause->autoneg = 0; /* We don't support ksettings, so can't pretend */ + pause->rx_pause = ns->ethtool.pauseparam.rx; + pause->tx_pause = ns->ethtool.pauseparam.tx; +} + +static int +nsim_set_pauseparam(struct net_device *dev, struct ethtool_pauseparam *pause) +{ + struct netdevsim *ns = netdev_priv(dev); + + if (pause->autoneg) + return -EINVAL; + + ns->ethtool.pauseparam.rx = pause->rx_pause; + ns->ethtool.pauseparam.tx = pause->tx_pause; + return 0; +} + +static int nsim_get_coalesce(struct net_device *dev, + struct ethtool_coalesce *coal, + struct kernel_ethtool_coalesce *kernel_coal, + struct netlink_ext_ack *extack) +{ + struct netdevsim *ns = netdev_priv(dev); + + memcpy(coal, &ns->ethtool.coalesce, sizeof(ns->ethtool.coalesce)); + return 0; +} + +static int nsim_set_coalesce(struct net_device *dev, + struct ethtool_coalesce *coal, + struct kernel_ethtool_coalesce *kernel_coal, + struct netlink_ext_ack *extack) +{ + struct netdevsim *ns = netdev_priv(dev); + + memcpy(&ns->ethtool.coalesce, coal, sizeof(ns->ethtool.coalesce)); + return 0; +} + +static void nsim_get_ringparam(struct net_device *dev, + struct ethtool_ringparam *ring, + struct kernel_ethtool_ringparam *kernel_ring, + struct netlink_ext_ack *extack) +{ + struct netdevsim *ns = netdev_priv(dev); + + memcpy(ring, &ns->ethtool.ring, sizeof(ns->ethtool.ring)); + kernel_ring->hds_thresh_max = NSIM_HDS_THRESHOLD_MAX; + + if (dev->cfg->hds_config == ETHTOOL_TCP_DATA_SPLIT_UNKNOWN) + kernel_ring->tcp_data_split = ETHTOOL_TCP_DATA_SPLIT_ENABLED; +} + +static int nsim_set_ringparam(struct net_device *dev, + struct ethtool_ringparam *ring, + struct kernel_ethtool_ringparam *kernel_ring, + struct netlink_ext_ack *extack) +{ + struct netdevsim *ns = netdev_priv(dev); + + ns->ethtool.ring.rx_pending = ring->rx_pending; + ns->ethtool.ring.rx_jumbo_pending = ring->rx_jumbo_pending; + ns->ethtool.ring.rx_mini_pending = ring->rx_mini_pending; + ns->ethtool.ring.tx_pending = ring->tx_pending; + return 0; +} + +static void +nsim_get_channels(struct net_device *dev, struct ethtool_channels *ch) +{ + struct netdevsim *ns = netdev_priv(dev); + + ch->max_combined = ns->nsim_bus_dev->num_queues; + ch->combined_count = ns->ethtool.channels; +} + +static void +nsim_wake_queues(struct net_device *dev) +{ + struct netdevsim *ns = netdev_priv(dev); + struct netdevsim *peer; + + synchronize_net(); + netif_tx_wake_all_queues(dev); + + rcu_read_lock(); + peer = rcu_dereference(ns->peer); + if (peer) + netif_tx_wake_all_queues(peer->netdev); + rcu_read_unlock(); +} + +static int +nsim_set_channels(struct net_device *dev, struct ethtool_channels *ch) +{ + struct netdevsim *ns = netdev_priv(dev); + int err; + + err = netif_set_real_num_queues(dev, ch->combined_count, + ch->combined_count); + if (err) + return err; + + ns->ethtool.channels = ch->combined_count; + + /* Only wake up queues if devices are linked */ + if (rcu_access_pointer(ns->peer)) + nsim_wake_queues(dev); + + return 0; +} + +static int +nsim_get_fecparam(struct net_device *dev, struct ethtool_fecparam *fecparam) +{ + struct netdevsim *ns = netdev_priv(dev); + + if (ns->ethtool.get_err) + return -ns->ethtool.get_err; + memcpy(fecparam, &ns->ethtool.fec, sizeof(ns->ethtool.fec)); + return 0; +} + +static int +nsim_set_fecparam(struct net_device *dev, struct ethtool_fecparam *fecparam) +{ + struct netdevsim *ns = netdev_priv(dev); + u32 fec; + + if (ns->ethtool.set_err) + return -ns->ethtool.set_err; + memcpy(&ns->ethtool.fec, fecparam, sizeof(ns->ethtool.fec)); + fec = fecparam->fec; + if (fec == ETHTOOL_FEC_AUTO) + fec |= ETHTOOL_FEC_OFF; + fec |= ETHTOOL_FEC_NONE; + ns->ethtool.fec.active_fec = 1 << (fls(fec) - 1); + return 0; +} + +static const struct ethtool_fec_hist_range netdevsim_fec_ranges[] = { + { 0, 0}, + { 1, 3}, + { 4, 7}, + { 0, 0} +}; + +static void +nsim_get_fec_stats(struct net_device *dev, struct ethtool_fec_stats *fec_stats, + struct ethtool_fec_hist *hist) +{ + struct ethtool_fec_hist_value *values = hist->values; + + hist->ranges = netdevsim_fec_ranges; + + fec_stats->corrected_blocks.total = 123; + fec_stats->uncorrectable_blocks.total = 4; + + values[0].per_lane[0] = 125; + values[0].per_lane[1] = 120; + values[0].per_lane[2] = 100; + values[0].per_lane[3] = 100; + values[1].sum = 12; + values[2].sum = 2; + values[2].per_lane[0] = 2; + values[2].per_lane[1] = 0; + values[2].per_lane[2] = 0; + values[2].per_lane[3] = 0; +} + +static int nsim_get_ts_info(struct net_device *dev, + struct kernel_ethtool_ts_info *info) +{ + struct netdevsim *ns = netdev_priv(dev); + + info->phc_index = mock_phc_index(ns->phc); + + return 0; +} + +static const struct ethtool_ops nsim_ethtool_ops = { + .supported_coalesce_params = ETHTOOL_COALESCE_ALL_PARAMS, + .supported_ring_params = ETHTOOL_RING_USE_TCP_DATA_SPLIT | + ETHTOOL_RING_USE_HDS_THRS, + .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS, + .get_pause_stats = nsim_get_pause_stats, + .get_pauseparam = nsim_get_pauseparam, + .set_pauseparam = nsim_set_pauseparam, + .set_coalesce = nsim_set_coalesce, + .get_coalesce = nsim_get_coalesce, + .get_ringparam = nsim_get_ringparam, + .set_ringparam = nsim_set_ringparam, + .get_channels = nsim_get_channels, + .set_channels = nsim_set_channels, + .get_fecparam = nsim_get_fecparam, + .set_fecparam = nsim_set_fecparam, + .get_fec_stats = nsim_get_fec_stats, + .get_ts_info = nsim_get_ts_info, +}; + +static void nsim_ethtool_ring_init(struct netdevsim *ns) +{ + ns->ethtool.ring.rx_pending = 512; + ns->ethtool.ring.rx_max_pending = 4096; + ns->ethtool.ring.rx_jumbo_max_pending = 4096; + ns->ethtool.ring.rx_mini_max_pending = 4096; + ns->ethtool.ring.tx_pending = 512; + ns->ethtool.ring.tx_max_pending = 4096; +} + +void nsim_ethtool_init(struct netdevsim *ns) +{ + struct dentry *ethtool, *dir; + + ns->netdev->ethtool_ops = &nsim_ethtool_ops; + + nsim_ethtool_ring_init(ns); + + ns->ethtool.pauseparam.report_stats_rx = true; + ns->ethtool.pauseparam.report_stats_tx = true; + + ns->ethtool.fec.fec = ETHTOOL_FEC_NONE; + ns->ethtool.fec.active_fec = ETHTOOL_FEC_NONE; + + ns->ethtool.channels = ns->nsim_bus_dev->num_queues; + + ethtool = debugfs_create_dir("ethtool", ns->nsim_dev_port->ddir); + ns->ethtool_ddir = ethtool; + + debugfs_create_u32("get_err", 0600, ethtool, &ns->ethtool.get_err); + debugfs_create_u32("set_err", 0600, ethtool, &ns->ethtool.set_err); + + dir = debugfs_create_dir("pause", ethtool); + debugfs_create_bool("report_stats_rx", 0600, dir, + &ns->ethtool.pauseparam.report_stats_rx); + debugfs_create_bool("report_stats_tx", 0600, dir, + &ns->ethtool.pauseparam.report_stats_tx); + + dir = debugfs_create_dir("ring", ethtool); + debugfs_create_u32("rx_max_pending", 0600, dir, + &ns->ethtool.ring.rx_max_pending); + debugfs_create_u32("rx_jumbo_max_pending", 0600, dir, + &ns->ethtool.ring.rx_jumbo_max_pending); + debugfs_create_u32("rx_mini_max_pending", 0600, dir, + &ns->ethtool.ring.rx_mini_max_pending); + debugfs_create_u32("tx_max_pending", 0600, dir, + &ns->ethtool.ring.tx_max_pending); +} + +void nsim_ethtool_fini(struct netdevsim *ns) +{ + debugfs_remove(ns->ethtool_ddir); +} -- cgit v1.3.1