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authorLinus Torvalds <torvalds@linux-foundation.org>2026-09-13 12:27:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-09-13 12:27:00 -0700
commit22098763a10d9c1340827fcf6edab66f153b27f0 (patch)
tree3962f95a34df034652ff93686cdd156c7197f2d9 /net/ethernet
downloadlinux-stable-22098763a10d9c1340827fcf6edab66f153b27f0.tar.gz
linux-stable-22098763a10d9c1340827fcf6edab66f153b27f0.zip
Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted
Pull tracing fixes from Steven Rostedt: - Don't destroy user event fields when removal fails User event fields are destroyed before the event is removed from visibility. But that can fail leaving the still visible event with no fields. Move the destroying of the fields to after the event is successfully removed from visibility. - Initialize function graph state is fork before calling copy_exec_state() For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, ftrace_graph_exit_task() will free the tasks ret_stack pointer. Since that pointer is still using the parent's ret_stack, it mistakenly frees the parent's pointer too. Call ftrace_graph_init() on the task first which will NULL out the new tasks's ret_stack and if the copy fails, it will not free anything. - Remove FGRAPH_MAX_INDEX The macro FGRAPH_MAX_INDEX was added but never used. Remove it. - Save ent_size in function graph printing of nested functions The function graph tracer needs to look at the next event to see if the next event is the return of the current function entry. If it is, it prints a single line: ktime_get(); Otherwise it prints it like a nested function: tick_nohz_irq_exit() { ktime_get(); kcpustat_irq_exit(); } In order to look at the next event, it must save the current event so that it has the information to print from it. It saves the event in the iterator descriptor called "ent". What it doesn't save is the ent_size of the event which is now used to know if the function graph arguments are to be printed. The peek doesn't save the size so the size used happens to be that of the size of the last event that was seen. Save the entry event size in the iterator descriptor so that the correct size is used. - Fix several errors with freeing data in the histogram code The histogram code had a lot of leaked or or incorrect accounting when failures happen. Correct them. - Fix histogram regression of .percent and .graph modifiers Up until 6.3 histogram values could have "percent" or "graph" modifiers that changed how they were printed. But a change that added restricting histograms values from being strings, stack traces and other modifiers inadvertently prevented them from using the percent and graph modifiers, which were legal use cases for values. Put back the percent and graph modifiers. - Fix various typos in the comments - Set the trace_clock before initializing a histogram with clock argument The histogram API allows the user to specific which trace clock to use via a "clock=" string. The histogram is set up first before the clock is checked. If the passed in clock is not valid, it exits without fully fixing up the histogram leaving it on the list and a use-after-free can trigger. Update the clock argument first and if it fails then exit gracefully before the histogram trigger is placed on any lists. - Restore :mod: trailer after parsing in ftrace_set_clr_event The function ftrace_set_clr_event() modifies the parse string and needs to put it back to what was passed in. It searches for ":mod:" via a strsep() but fails to put back the first ':' in the string. Add back the ':' in the passed in string. - Take trace_array reference when opening a tracer options file The options files are dynamically created and some tracers add their own options. When a tracer adds their own list of options, the trace_array holding them has an array to hold the list of options for each tracer. This array increases in size via a krealloc(), and the new entry gets a newly allocated array to hold the options of the new tracer being added. The element in each entry of the tracer's option array holds a pointer back to the trace_array, a pointer to the tracer it is associated to, a pointer to the flags of the option. The issue is that these arrays are freed when the trace_array is freed when its instance it represents is removed from the instances directory. There's a race that an open of one of these options files can happen when the instance is being removed. Add a new helper function to be called by the open function of the options file to iterate all existing trace_arrays under a lock and find the one that has the given option element in one of it's tracer arrays. If found, then update the associated trace_array's reference counter to keep it from being freed. If not found, have the open call return -ENODEV. - Disable interrupts when acquiring the lock in rb_wake_up_waiters() The function rb_wake_up_waiters() assumes it will be called in interrupt context and does not disable irqs when taking cpu_buffer->reader_lock, which can be called in hard interrupt context. The issue is in PREEMPT_RT, this function is called in thread context leaving this lock open to a deadlock. Take the lock with interrupts disabled. - Use rcu_assign_pointer() for tmp_ops filter hash The tmp_ops used in update_ftrace_direct_mod() assigns its filter_hash field directly, but that field is annotated as __rcu and sparse complains. Assign it with rcu_assign_pointer() - Fix use-after-free in enable_trigger_private_data_free() The trace_event_call is accessed through the event_trigger_data's trace_event_file pointer to put the trace_event_call on freeing. The issue is that the trace_event_file data may have been freed already causing a use-after-free. Add a field to the event_trigger_data that points directly to the trace_event_call so that it can decrement its reference directly without needing to go through the trace_event_file. - Fix accounting of buffer data remote headers trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the number of pages is needed for the asked for size as it doesn't take into account the meta data on each page. Add a helper function to do the calculation properly and use that in these functions. - Catch nr_page_va overflow in ring_buffer_desc sizing The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. - Do not resize the subbuf order if any per_cpu buffer is disabled The mmapping of ring buffers disables resizing the subbuffers, but it is done per-cpu whereas the subbuf size change is done for all the per_cpu buffers under the buffer->mutex. It could change the size of some while the mapping is happening on others. Have the resize of the subbuf order check all the per_cpu buffers under the lock to see if any of them is disabled before starting and causing an inconsistency between buffers that are being mapped. * tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits) ring-buffer: Check resize_disabled before publishing the new subbuf order tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing tracing/remotes: Account for ring buffer page header in size calculation tracing: Don't dereference trace_event_file in deferred trigger free ftrace: Use rcu_assign_pointer() for tmp_ops filter hash ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters() tracing: Take trace_array reference when opening a tracer options file tracing: Fix ring_buffer_read_page_size() kernel-doc tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event() tracing: Fix memory corruption from a "STACKTRACE" histogram key tracing: Fix memory corruption from the histogram stacktrace modifier tracing: Undo the registration when enabling the histogram trigger fails tracing: Take the reference before publishing the named histogram trigger tracing: Set the trace clock before registering the histogram trigger tracing: Fix typo "preceeded" in comment tracing: Fix typo "availabe" in comment tracing: Let histogram values keep the percent and graph modifiers tracing: Keep the entry count when the histogram stats allocation fails tracing: Free histogram the field rejected for a bad modifier tracing: Free histogram the var ref when its initialization fails ...
Diffstat (limited to 'net/ethernet')
-rw-r--r--net/ethernet/Makefile6
-rw-r--r--net/ethernet/eth.c638
2 files changed, 644 insertions, 0 deletions
diff --git a/net/ethernet/Makefile b/net/ethernet/Makefile
new file mode 100644
index 000000000..e03eff94e
--- /dev/null
+++ b/net/ethernet/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the Linux Ethernet layer.
+#
+
+obj-y += eth.o
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
new file mode 100644
index 000000000..d9faadbe9
--- /dev/null
+++ b/net/ethernet/eth.c
@@ -0,0 +1,638 @@
+// 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.
+ *
+ * Ethernet-type device handling.
+ *
+ * Version: @(#)eth.c 1.0.7 05/25/93
+ *
+ * Authors: Ross Biro
+ * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ * Mark Evans, <evansmp@uhura.aston.ac.uk>
+ * Florian La Roche, <rzsfl@rz.uni-sb.de>
+ * Alan Cox, <gw4pts@gw4pts.ampr.org>
+ *
+ * Fixes:
+ * Mr Linux : Arp problems
+ * Alan Cox : Generic queue tidyup (very tiny here)
+ * Alan Cox : eth_header ntohs should be htons
+ * Alan Cox : eth_rebuild_header missing an htons and
+ * minor other things.
+ * Tegge : Arp bug fixes.
+ * Florian : Removed many unnecessary functions, code cleanup
+ * and changes for new arp and skbuff.
+ * Alan Cox : Redid header building to reflect new format.
+ * Alan Cox : ARP only when compiled with CONFIG_INET
+ * Greg Page : 802.2 and SNAP stuff.
+ * Alan Cox : MAC layer pointers/new format.
+ * Paul Gortmaker : eth_copy_and_sum shouldn't csum padding.
+ * Alan Cox : Protect against forwarding explosions with
+ * older network drivers and IFF_ALLMULTI.
+ * Christer Weinigel : Better rebuild header message.
+ * Andrew Morton : 26Feb01: kill ether_setup() - use netdev_boot_setup().
+ */
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/ip.h>
+#include <linux/netdevice.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/if_ether.h>
+#include <linux/of_net.h>
+#include <linux/pci.h>
+#include <linux/property.h>
+#include <net/dst.h>
+#include <net/arp.h>
+#include <net/sock.h>
+#include <net/ipv6.h>
+#include <net/ip.h>
+#include <net/dsa.h>
+#include <net/flow_dissector.h>
+#include <net/gro.h>
+#include <linux/uaccess.h>
+#include <net/pkt_sched.h>
+
+/**
+ * eth_header - create the Ethernet header
+ * @skb: buffer to alter
+ * @dev: source device
+ * @type: Ethernet type field
+ * @daddr: destination address (NULL leave destination address)
+ * @saddr: source address (NULL use device source address)
+ * @len: packet length (<= skb->len)
+ *
+ *
+ * Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length
+ * in here instead.
+ */
+int eth_header(struct sk_buff *skb, struct net_device *dev,
+ unsigned short type,
+ const void *daddr, const void *saddr, unsigned int len)
+{
+ struct ethhdr *eth = skb_push(skb, ETH_HLEN);
+
+ if (type != ETH_P_802_3 && type != ETH_P_802_2)
+ eth->h_proto = htons(type);
+ else
+ eth->h_proto = htons(len);
+
+ /*
+ * Set the source hardware address.
+ */
+
+ if (!saddr)
+ saddr = dev->dev_addr;
+ memcpy(eth->h_source, saddr, ETH_ALEN);
+
+ if (daddr) {
+ memcpy(eth->h_dest, daddr, ETH_ALEN);
+ return ETH_HLEN;
+ }
+
+ /*
+ * Anyway, the loopback-device should never use this function...
+ */
+
+ if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
+ eth_zero_addr(eth->h_dest);
+ return ETH_HLEN;
+ }
+
+ return -ETH_HLEN;
+}
+EXPORT_SYMBOL(eth_header);
+
+/**
+ * eth_get_headlen - determine the length of header for an ethernet frame
+ * @dev: pointer to network device
+ * @data: pointer to start of frame
+ * @len: total length of frame
+ *
+ * Make a best effort attempt to pull the length for all of the headers for
+ * a given frame in a linear buffer.
+ */
+u32 eth_get_headlen(const struct net_device *dev, const void *data, u32 len)
+{
+ const unsigned int flags = FLOW_DISSECTOR_F_PARSE_1ST_FRAG;
+ const struct ethhdr *eth = (const struct ethhdr *)data;
+ struct flow_keys_basic keys;
+
+ /* this should never happen, but better safe than sorry */
+ if (unlikely(len < sizeof(*eth)))
+ return len;
+
+ /* parse any remaining L2/L3 headers, check for L4 */
+ if (!skb_flow_dissect_flow_keys_basic(dev_net(dev), NULL, &keys, data,
+ eth->h_proto, sizeof(*eth),
+ len, flags))
+ return max_t(u32, keys.control.thoff, sizeof(*eth));
+
+ /* parse for any L4 headers */
+ return min_t(u32, __skb_get_poff(NULL, data, &keys, len), len);
+}
+EXPORT_SYMBOL(eth_get_headlen);
+
+/**
+ * eth_type_trans - determine the packet's protocol ID.
+ * @skb: received socket data
+ * @dev: receiving network device
+ *
+ * The rule here is that we
+ * assume 802.3 if the type field is short enough to be a length.
+ * This is normal practice and works for any 'now in use' protocol.
+ */
+__be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
+{
+ const unsigned short *sap;
+ const struct ethhdr *eth;
+ __be16 res;
+
+ skb->dev = dev;
+ skb_reset_mac_header(skb);
+
+ eth = eth_skb_pull_mac(skb);
+ eth_skb_pkt_type(skb, dev);
+
+ /*
+ * Some variants of DSA tagging don't have an ethertype field
+ * at all, so we check here whether one of those tagging
+ * variants has been configured on the receiving interface,
+ * and if so, set skb->protocol without looking at the packet.
+ */
+ if (unlikely(netdev_uses_dsa(dev)))
+ return htons(ETH_P_XDSA);
+
+ if (likely(eth_proto_is_802_3(eth->h_proto)))
+ return eth->h_proto;
+
+ /*
+ * This is a magic hack to spot IPX packets. Older Novell breaks
+ * the protocol design and runs IPX over 802.3 without an 802.2 LLC
+ * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
+ * won't work for fault tolerant netware but does for the rest.
+ * We use skb->dev as temporary storage to not hit
+ * CONFIG_STACKPROTECTOR_STRONG=y costs on some platforms.
+ */
+ sap = skb_header_pointer(skb, 0, sizeof(*sap), &skb->dev);
+ res = (sap && *sap == 0xFFFF) ? htons(ETH_P_802_3) : htons(ETH_P_802_2);
+
+ /* restore skb->dev in case it was mangled by skb_header_pointer(). */
+ skb->dev = dev;
+ return res;
+}
+EXPORT_SYMBOL(eth_type_trans);
+
+int eth_header_parse(const struct sk_buff *skb, const struct net_device *dev,
+ unsigned char *haddr)
+{
+ const struct ethhdr *eth = eth_hdr(skb);
+
+ memcpy(haddr, eth->h_source, ETH_ALEN);
+ return ETH_ALEN;
+}
+EXPORT_SYMBOL(eth_header_parse);
+
+/**
+ * eth_header_cache - fill cache entry from neighbour
+ * @neigh: source neighbour
+ * @hh: destination cache entry
+ * @type: Ethernet type field
+ *
+ * Create an Ethernet header template from the neighbour.
+ */
+int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type)
+{
+ struct ethhdr *eth;
+ const struct net_device *dev = neigh->dev;
+
+ eth = (struct ethhdr *)
+ (((u8 *) hh->hh_data) + (HH_DATA_OFF(sizeof(*eth))));
+
+ if (type == htons(ETH_P_802_3))
+ return -1;
+
+ eth->h_proto = type;
+ memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
+ memcpy(eth->h_dest, neigh->ha, ETH_ALEN);
+
+ /* Pairs with READ_ONCE() in neigh_resolve_output(),
+ * neigh_hh_output() and neigh_update_hhs().
+ */
+ smp_store_release(&hh->hh_len, ETH_HLEN);
+
+ return 0;
+}
+EXPORT_SYMBOL(eth_header_cache);
+
+/**
+ * eth_header_cache_update - update cache entry
+ * @hh: destination cache entry
+ * @dev: network device
+ * @haddr: new hardware address
+ *
+ * Called by Address Resolution module to notify changes in address.
+ */
+void eth_header_cache_update(struct hh_cache *hh,
+ const struct net_device *dev,
+ const unsigned char *haddr)
+{
+ memcpy(((u8 *) hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
+ haddr, ETH_ALEN);
+}
+EXPORT_SYMBOL(eth_header_cache_update);
+
+/**
+ * eth_header_parse_protocol - extract protocol from L2 header
+ * @skb: packet to extract protocol from
+ */
+__be16 eth_header_parse_protocol(const struct sk_buff *skb)
+{
+ const struct ethhdr *eth = eth_hdr(skb);
+
+ return eth->h_proto;
+}
+EXPORT_SYMBOL(eth_header_parse_protocol);
+
+/**
+ * eth_prepare_mac_addr_change - prepare for mac change
+ * @dev: network device
+ * @p: socket address
+ */
+int eth_prepare_mac_addr_change(struct net_device *dev, void *p)
+{
+ struct sockaddr *addr = p;
+
+ if (!(dev->priv_flags & IFF_LIVE_ADDR_CHANGE) && netif_running(dev))
+ return -EBUSY;
+ if (!is_valid_ether_addr(addr->sa_data))
+ return -EADDRNOTAVAIL;
+ return 0;
+}
+EXPORT_SYMBOL(eth_prepare_mac_addr_change);
+
+/**
+ * eth_commit_mac_addr_change - commit mac change
+ * @dev: network device
+ * @p: socket address
+ */
+void eth_commit_mac_addr_change(struct net_device *dev, void *p)
+{
+ struct sockaddr *addr = p;
+
+ eth_hw_addr_set(dev, addr->sa_data);
+}
+EXPORT_SYMBOL(eth_commit_mac_addr_change);
+
+/**
+ * eth_mac_addr - set new Ethernet hardware address
+ * @dev: network device
+ * @p: socket address
+ *
+ * Change hardware address of device.
+ *
+ * This doesn't change hardware matching, so needs to be overridden
+ * for most real devices.
+ */
+int eth_mac_addr(struct net_device *dev, void *p)
+{
+ int ret;
+
+ ret = eth_prepare_mac_addr_change(dev, p);
+ if (ret < 0)
+ return ret;
+ eth_commit_mac_addr_change(dev, p);
+ return 0;
+}
+EXPORT_SYMBOL(eth_mac_addr);
+
+int eth_validate_addr(struct net_device *dev)
+{
+ if (!is_valid_ether_addr(dev->dev_addr))
+ return -EADDRNOTAVAIL;
+
+ return 0;
+}
+EXPORT_SYMBOL(eth_validate_addr);
+
+const struct header_ops eth_header_ops ____cacheline_aligned = {
+ .create = eth_header,
+ .parse = eth_header_parse,
+ .cache = eth_header_cache,
+ .cache_update = eth_header_cache_update,
+ .parse_protocol = eth_header_parse_protocol,
+};
+
+/**
+ * ether_setup - setup Ethernet network device
+ * @dev: network device
+ *
+ * Fill in the fields of the device structure with Ethernet-generic values.
+ */
+void ether_setup(struct net_device *dev)
+{
+ dev->header_ops = &eth_header_ops;
+ dev->type = ARPHRD_ETHER;
+ dev->hard_header_len = ETH_HLEN;
+ dev->min_header_len = ETH_HLEN;
+ dev->mtu = ETH_DATA_LEN;
+ dev->min_mtu = ETH_MIN_MTU;
+ dev->max_mtu = ETH_DATA_LEN;
+ dev->addr_len = ETH_ALEN;
+ dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
+ dev->flags = IFF_BROADCAST|IFF_MULTICAST;
+ dev->priv_flags |= IFF_TX_SKB_SHARING;
+
+ eth_broadcast_addr(dev->broadcast);
+
+}
+EXPORT_SYMBOL(ether_setup);
+
+/**
+ * alloc_etherdev_mqs - Allocates and sets up an Ethernet device
+ * @sizeof_priv: Size of additional driver-private structure to be allocated
+ * for this Ethernet device
+ * @txqs: The number of TX queues this device has.
+ * @rxqs: The number of RX queues this device has.
+ *
+ * Fill in the fields of the device structure with Ethernet-generic
+ * values. Basically does everything except registering the device.
+ *
+ * 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_etherdev_mqs(int sizeof_priv, unsigned int txqs,
+ unsigned int rxqs)
+{
+ return alloc_netdev_mqs(sizeof_priv, "eth%d", NET_NAME_ENUM,
+ ether_setup, txqs, rxqs);
+}
+EXPORT_SYMBOL(alloc_etherdev_mqs);
+
+ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len)
+{
+ return sysfs_emit(buf, "%*phC\n", len, addr);
+}
+EXPORT_SYMBOL(sysfs_format_mac);
+
+struct sk_buff *eth_gro_receive(struct list_head *head, struct sk_buff *skb)
+{
+ const struct packet_offload *ptype;
+ unsigned int hlen, off_eth;
+ struct sk_buff *pp = NULL;
+ struct ethhdr *eh, *eh2;
+ struct sk_buff *p;
+ __be16 type;
+ int flush = 1;
+
+ off_eth = skb_gro_offset(skb);
+ hlen = off_eth + sizeof(*eh);
+ eh = skb_gro_header(skb, hlen, off_eth);
+ if (unlikely(!eh))
+ goto out;
+
+ flush = 0;
+
+ list_for_each_entry(p, head, list) {
+ if (!NAPI_GRO_CB(p)->same_flow)
+ continue;
+
+ eh2 = (struct ethhdr *)(p->data + off_eth);
+ if (compare_ether_header(eh, eh2)) {
+ NAPI_GRO_CB(p)->same_flow = 0;
+ continue;
+ }
+ }
+
+ type = eh->h_proto;
+
+ ptype = gro_find_receive_by_type(type);
+ if (ptype == NULL) {
+ flush = 1;
+ goto out;
+ }
+
+ skb_gro_pull(skb, sizeof(*eh));
+ skb_gro_postpull_rcsum(skb, eh, sizeof(*eh));
+
+ pp = indirect_call_gro_receive_inet(ptype->callbacks.gro_receive,
+ ipv6_gro_receive, inet_gro_receive,
+ head, skb);
+
+out:
+ skb_gro_flush_final(skb, pp, flush);
+
+ return pp;
+}
+EXPORT_SYMBOL(eth_gro_receive);
+
+int eth_gro_complete(struct sk_buff *skb, int nhoff)
+{
+ struct ethhdr *eh = (struct ethhdr *)(skb->data + nhoff);
+ __be16 type = eh->h_proto;
+ struct packet_offload *ptype;
+ int err = -ENOSYS;
+
+ if (skb->encapsulation)
+ skb_set_inner_mac_header(skb, nhoff);
+
+ ptype = gro_find_complete_by_type(type);
+ if (ptype != NULL)
+ err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete,
+ ipv6_gro_complete, inet_gro_complete,
+ skb, nhoff + sizeof(*eh));
+
+ return err;
+}
+EXPORT_SYMBOL(eth_gro_complete);
+
+static struct packet_offload eth_packet_offload __read_mostly = {
+ .type = cpu_to_be16(ETH_P_TEB),
+ .priority = 10,
+ .callbacks = {
+ .gro_receive = eth_gro_receive,
+ .gro_complete = eth_gro_complete,
+ },
+};
+
+static int __init eth_offload_init(void)
+{
+ dev_add_offload(&eth_packet_offload);
+
+ return 0;
+}
+
+fs_initcall(eth_offload_init);
+
+unsigned char * __weak arch_get_platform_mac_address(void)
+{
+ return NULL;
+}
+
+int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr)
+{
+ unsigned char *addr;
+ int ret;
+
+ ret = of_get_mac_address(dev->of_node, mac_addr);
+ if (!ret)
+ return 0;
+
+ addr = arch_get_platform_mac_address();
+ if (!addr)
+ return -ENODEV;
+
+ ether_addr_copy(mac_addr, addr);
+
+ return 0;
+}
+EXPORT_SYMBOL(eth_platform_get_mac_address);
+
+/**
+ * platform_get_ethdev_address - Set netdev's MAC address from a given device
+ * @dev: Pointer to the device
+ * @netdev: Pointer to netdev to write the address to
+ *
+ * Wrapper around eth_platform_get_mac_address() which writes the address
+ * directly to netdev->dev_addr.
+ */
+int platform_get_ethdev_address(struct device *dev, struct net_device *netdev)
+{
+ u8 addr[ETH_ALEN] __aligned(2);
+ int ret;
+
+ ret = eth_platform_get_mac_address(dev, addr);
+ if (!ret)
+ eth_hw_addr_set(netdev, addr);
+ return ret;
+}
+EXPORT_SYMBOL(platform_get_ethdev_address);
+
+/**
+ * nvmem_get_mac_address - Obtain the MAC address from an nvmem cell named
+ * 'mac-address' associated with given device.
+ *
+ * @dev: Device with which the mac-address cell is associated.
+ * @addrbuf: Buffer to which the MAC address will be copied on success.
+ *
+ * Returns 0 on success or a negative error number on failure.
+ */
+int nvmem_get_mac_address(struct device *dev, void *addrbuf)
+{
+ struct nvmem_cell *cell;
+ const void *mac;
+ size_t len;
+
+ cell = nvmem_cell_get(dev, "mac-address");
+ if (IS_ERR(cell))
+ return PTR_ERR(cell);
+
+ mac = nvmem_cell_read(cell, &len);
+ nvmem_cell_put(cell);
+
+ if (IS_ERR(mac))
+ return PTR_ERR(mac);
+
+ if (len != ETH_ALEN || !is_valid_ether_addr(mac)) {
+ kfree(mac);
+ return -EINVAL;
+ }
+
+ ether_addr_copy(addrbuf, mac);
+ kfree(mac);
+
+ return 0;
+}
+
+static int fwnode_get_mac_addr(struct fwnode_handle *fwnode,
+ const char *name, char *addr)
+{
+ int ret;
+
+ ret = fwnode_property_read_u8_array(fwnode, name, addr, ETH_ALEN);
+ if (ret)
+ return ret;
+
+ if (!is_valid_ether_addr(addr))
+ return -EINVAL;
+ return 0;
+}
+
+/**
+ * fwnode_get_mac_address - Get the MAC from the firmware node
+ * @fwnode: Pointer to the firmware node
+ * @addr: Address of buffer to store the MAC in
+ *
+ * Search the firmware node for the best MAC address to use. 'mac-address' is
+ * checked first, because that is supposed to contain to "most recent" MAC
+ * address. If that isn't set, then 'local-mac-address' is checked next,
+ * because that is the default address. If that isn't set, then the obsolete
+ * 'address' is checked, just in case we're using an old device tree.
+ *
+ * Note that the 'address' property is supposed to contain a virtual address of
+ * the register set, but some DTS files have redefined that property to be the
+ * MAC address.
+ *
+ * All-zero MAC addresses are rejected, because those could be properties that
+ * exist in the firmware tables, but were not updated by the firmware. For
+ * example, the DTS could define 'mac-address' and 'local-mac-address', with
+ * zero MAC addresses. Some older U-Boots only initialized 'local-mac-address'.
+ * In this case, the real MAC is in 'local-mac-address', and 'mac-address'
+ * exists but is all zeros.
+ */
+int fwnode_get_mac_address(struct fwnode_handle *fwnode, char *addr)
+{
+ if (!fwnode_get_mac_addr(fwnode, "mac-address", addr) ||
+ !fwnode_get_mac_addr(fwnode, "local-mac-address", addr) ||
+ !fwnode_get_mac_addr(fwnode, "address", addr))
+ return 0;
+
+ return -ENOENT;
+}
+EXPORT_SYMBOL(fwnode_get_mac_address);
+
+/**
+ * device_get_mac_address - Get the MAC for a given device
+ * @dev: Pointer to the device
+ * @addr: Address of buffer to store the MAC in
+ */
+int device_get_mac_address(struct device *dev, char *addr)
+{
+ if (!fwnode_get_mac_address(dev_fwnode(dev), addr))
+ return 0;
+
+ return nvmem_get_mac_address(dev, addr);
+}
+EXPORT_SYMBOL(device_get_mac_address);
+
+/**
+ * device_get_ethdev_address - Set netdev's MAC address from a given device
+ * @dev: Pointer to the device
+ * @netdev: Pointer to netdev to write the address to
+ *
+ * Wrapper around device_get_mac_address() which writes the address
+ * directly to netdev->dev_addr.
+ */
+int device_get_ethdev_address(struct device *dev, struct net_device *netdev)
+{
+ u8 addr[ETH_ALEN];
+ int ret;
+
+ ret = device_get_mac_address(dev, addr);
+ if (!ret)
+ eth_hw_addr_set(netdev, addr);
+ return ret;
+}
+EXPORT_SYMBOL(device_get_ethdev_address);