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 --- net/802/fddi.c | 184 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 184 insertions(+) create mode 100644 net/802/fddi.c (limited to 'net/802/fddi.c') diff --git a/net/802/fddi.c b/net/802/fddi.c new file mode 100644 index 000000000..e26f4549e --- /dev/null +++ b/net/802/fddi.c @@ -0,0 +1,184 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * FDDI-type device handling. + * + * Version: @(#)fddi.c 1.0.0 08/12/96 + * + * Authors: Lawrence V. Stefani, + * + * fddi.c is based on previous eth.c and tr.c work by + * Ross Biro + * Fred N. van Kempen, + * Mark Evans, + * Florian La Roche, + * Alan Cox, + * + * Changes + * Alan Cox : New arp/rebuild header + * Maciej W. Rozycki : IPv6 support + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * Create the FDDI MAC header for an arbitrary protocol layer + * + * saddr=NULL means use device source address + * daddr=NULL means leave destination address (eg unresolved arp) + */ + +static int fddi_header(struct sk_buff *skb, struct net_device *dev, + unsigned short type, + const void *daddr, const void *saddr, unsigned int len) +{ + int hl = FDDI_K_SNAP_HLEN; + struct fddihdr *fddi; + + if(type != ETH_P_IP && type != ETH_P_IPV6 && type != ETH_P_ARP) + hl=FDDI_K_8022_HLEN-3; + fddi = skb_push(skb, hl); + fddi->fc = FDDI_FC_K_ASYNC_LLC_DEF; + if(type == ETH_P_IP || type == ETH_P_IPV6 || type == ETH_P_ARP) + { + fddi->hdr.llc_snap.dsap = FDDI_EXTENDED_SAP; + fddi->hdr.llc_snap.ssap = FDDI_EXTENDED_SAP; + fddi->hdr.llc_snap.ctrl = FDDI_UI_CMD; + fddi->hdr.llc_snap.oui[0] = 0x00; + fddi->hdr.llc_snap.oui[1] = 0x00; + fddi->hdr.llc_snap.oui[2] = 0x00; + fddi->hdr.llc_snap.ethertype = htons(type); + } + + /* Set the source and destination hardware addresses */ + + if (saddr != NULL) + memcpy(fddi->saddr, saddr, dev->addr_len); + else + memcpy(fddi->saddr, dev->dev_addr, dev->addr_len); + + if (daddr != NULL) + { + memcpy(fddi->daddr, daddr, dev->addr_len); + return hl; + } + + return -hl; +} + +/* + * Determine the packet's protocol ID and fill in skb fields. + * This routine is called before an incoming packet is passed + * up. It's used to fill in specific skb fields and to set + * the proper pointer to the start of packet data (skb->data). + */ + +__be16 fddi_type_trans(struct sk_buff *skb, struct net_device *dev) +{ + struct fddihdr *fddi = (struct fddihdr *)skb->data; + __be16 type; + + /* + * Set mac.raw field to point to FC byte, set data field to point + * to start of packet data. Assume 802.2 SNAP frames for now. + */ + + skb->dev = dev; + skb_reset_mac_header(skb); /* point to frame control (FC) */ + + if (skb->len < FDDI_K_8022_HLEN) + return htons(0); + + if(fddi->hdr.llc_8022_1.dsap==0xe0) + { + skb_pull(skb, FDDI_K_8022_HLEN-3); + type = htons(ETH_P_802_2); + } + else + { + if (skb->len < FDDI_K_SNAP_HLEN) + return htons(0); + skb_pull(skb, FDDI_K_SNAP_HLEN); /* adjust for 21 byte header */ + type=fddi->hdr.llc_snap.ethertype; + } + + /* Set packet type based on destination address and flag settings */ + + if (*fddi->daddr & 0x01) + { + if (memcmp(fddi->daddr, dev->broadcast, FDDI_K_ALEN) == 0) + skb->pkt_type = PACKET_BROADCAST; + else + skb->pkt_type = PACKET_MULTICAST; + } + + else if (dev->flags & IFF_PROMISC) + { + if (memcmp(fddi->daddr, dev->dev_addr, FDDI_K_ALEN)) + skb->pkt_type = PACKET_OTHERHOST; + } + + /* Assume 802.2 SNAP frames, for now */ + + return type; +} + +EXPORT_SYMBOL(fddi_type_trans); + +static const struct header_ops fddi_header_ops = { + .create = fddi_header, +}; + + +static void fddi_setup(struct net_device *dev) +{ + dev->header_ops = &fddi_header_ops; + dev->type = ARPHRD_FDDI; + dev->hard_header_len = FDDI_K_SNAP_HLEN+3; /* Assume 802.2 SNAP hdr len + 3 pad bytes */ + dev->mtu = FDDI_K_SNAP_DLEN; /* Assume max payload of 802.2 SNAP frame */ + dev->min_mtu = FDDI_K_SNAP_HLEN; + dev->max_mtu = FDDI_K_SNAP_DLEN; + dev->addr_len = FDDI_K_ALEN; + dev->tx_queue_len = 100; /* Long queues on FDDI */ + dev->flags = IFF_BROADCAST | IFF_MULTICAST; + + memset(dev->broadcast, 0xFF, FDDI_K_ALEN); +} + +/** + * alloc_fddidev - Register FDDI device + * @sizeof_priv: Size of additional driver-private structure to be allocated + * for this FDDI device + * + * Fill in the fields of the device structure with FDDI-generic values. + * + * Constructs a new net device, complete with a private data area of + * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for + * this private data area. + */ +struct net_device *alloc_fddidev(int sizeof_priv) +{ + return alloc_netdev(sizeof_priv, "fddi%d", NET_NAME_UNKNOWN, + fddi_setup); +} +EXPORT_SYMBOL(alloc_fddidev); + +MODULE_DESCRIPTION("Core routines for FDDI network devices"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1