Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 745 insertions, 0 deletions

diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
new file mode 100644
index 000000000..cdf6c6060
--- /dev/null
+++ b/arch/x86/kernel/unwind_orc.c
@@ -0,0 +1,745 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/objtool.h>
+#include <linux/module.h>
+#include <linux/sort.h>
+#include <asm/ptrace.h>
+#include <asm/stacktrace.h>
+#include <asm/unwind.h>
+#include <asm/orc_types.h>
+#include <asm/orc_lookup.h>
+
+#define orc_warn(fmt, ...) \
+	printk_deferred_once(KERN_WARNING "WARNING: " fmt, ##__VA_ARGS__)
+
+#define orc_warn_current(args...)					\
+({									\
+	if (state->task == current && !state->error)			\
+		orc_warn(args);						\
+})
+
+extern int __start_orc_unwind_ip[];
+extern int __stop_orc_unwind_ip[];
+extern struct orc_entry __start_orc_unwind[];
+extern struct orc_entry __stop_orc_unwind[];
+
+static bool orc_init __ro_after_init;
+static unsigned int lookup_num_blocks __ro_after_init;
+
+static inline unsigned long orc_ip(const int *ip)
+{
+	return (unsigned long)ip + *ip;
+}
+
+static struct orc_entry *__orc_find(int *ip_table, struct orc_entry *u_table,
+				    unsigned int num_entries, unsigned long ip)
+{
+	int *first = ip_table;
+	int *last = ip_table + num_entries - 1;
+	int *mid = first, *found = first;
+
+	if (!num_entries)
+		return NULL;
+
+	/*
+	 * Do a binary range search to find the rightmost duplicate of a given
+	 * starting address.  Some entries are section terminators which are
+	 * "weak" entries for ensuring there are no gaps.  They should be
+	 * ignored when they conflict with a real entry.
+	 */
+	while (first <= last) {
+		mid = first + ((last - first) / 2);
+
+		if (orc_ip(mid) <= ip) {
+			found = mid;
+			first = mid + 1;
+		} else
+			last = mid - 1;
+	}
+
+	return u_table + (found - ip_table);
+}
+
+#ifdef CONFIG_MODULES
+static struct orc_entry *orc_module_find(unsigned long ip)
+{
+	struct module *mod;
+
+	mod = __module_address(ip);
+	if (!mod || !mod->arch.orc_unwind || !mod->arch.orc_unwind_ip)
+		return NULL;
+	return __orc_find(mod->arch.orc_unwind_ip, mod->arch.orc_unwind,
+			  mod->arch.num_orcs, ip);
+}
+#else
+static struct orc_entry *orc_module_find(unsigned long ip)
+{
+	return NULL;
+}
+#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+static struct orc_entry *orc_find(unsigned long ip);
+
+/*
+ * Ftrace dynamic trampolines do not have orc entries of their own.
+ * But they are copies of the ftrace entries that are static and
+ * defined in ftrace_*.S, which do have orc entries.
+ *
+ * If the unwinder comes across a ftrace trampoline, then find the
+ * ftrace function that was used to create it, and use that ftrace
+ * function's orc entry, as the placement of the return code in
+ * the stack will be identical.
+ */
+static struct orc_entry *orc_ftrace_find(unsigned long ip)
+{
+	struct ftrace_ops *ops;
+	unsigned long tramp_addr, offset;
+
+	ops = ftrace_ops_trampoline(ip);
+	if (!ops)
+		return NULL;
+
+	/* Set tramp_addr to the start of the code copied by the trampoline */
+	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
+		tramp_addr = (unsigned long)ftrace_regs_caller;
+	else
+		tramp_addr = (unsigned long)ftrace_caller;
+
+	/* Now place tramp_addr to the location within the trampoline ip is at */
+	offset = ip - ops->trampoline;
+	tramp_addr += offset;
+
+	/* Prevent unlikely recursion */
+	if (ip == tramp_addr)
+		return NULL;
+
+	return orc_find(tramp_addr);
+}
+#else
+static struct orc_entry *orc_ftrace_find(unsigned long ip)
+{
+	return NULL;
+}
+#endif
+
+/*
+ * If we crash with IP==0, the last successfully executed instruction
+ * was probably an indirect function call with a NULL function pointer,
+ * and we don't have unwind information for NULL.
+ * This hardcoded ORC entry for IP==0 allows us to unwind from a NULL function
+ * pointer into its parent and then continue normally from there.
+ */
+static struct orc_entry null_orc_entry = {
+	.sp_offset = sizeof(long),
+	.sp_reg = ORC_REG_SP,
+	.bp_reg = ORC_REG_UNDEFINED,
+	.type = UNWIND_HINT_TYPE_CALL
+};
+
+#ifdef CONFIG_CALL_THUNKS
+static struct orc_entry *orc_callthunk_find(unsigned long ip)
+{
+	if (!is_callthunk((void *)ip))
+		return NULL;
+
+	return &null_orc_entry;
+}
+#else
+static struct orc_entry *orc_callthunk_find(unsigned long ip)
+{
+	return NULL;
+}
+#endif
+
+/* Fake frame pointer entry -- used as a fallback for generated code */
+static struct orc_entry orc_fp_entry = {
+	.type		= UNWIND_HINT_TYPE_CALL,
+	.sp_reg		= ORC_REG_BP,
+	.sp_offset	= 16,
+	.bp_reg		= ORC_REG_PREV_SP,
+	.bp_offset	= -16,
+	.end		= 0,
+};
+
+static struct orc_entry *orc_find(unsigned long ip)
+{
+	static struct orc_entry *orc;
+
+	if (ip == 0)
+		return &null_orc_entry;
+
+	/* For non-init vmlinux addresses, use the fast lookup table: */
+	if (ip >= LOOKUP_START_IP && ip < LOOKUP_STOP_IP) {
+		unsigned int idx, start, stop;
+
+		idx = (ip - LOOKUP_START_IP) / LOOKUP_BLOCK_SIZE;
+
+		if (unlikely((idx >= lookup_num_blocks-1))) {
+			orc_warn("WARNING: bad lookup idx: idx=%u num=%u ip=%pB\n",
+				 idx, lookup_num_blocks, (void *)ip);
+			return NULL;
+		}
+
+		start = orc_lookup[idx];
+		stop = orc_lookup[idx + 1] + 1;
+
+		if (unlikely((__start_orc_unwind + start >= __stop_orc_unwind) ||
+			     (__start_orc_unwind + stop > __stop_orc_unwind))) {
+			orc_warn("WARNING: bad lookup value: idx=%u num=%u start=%u stop=%u ip=%pB\n",
+				 idx, lookup_num_blocks, start, stop, (void *)ip);
+			return NULL;
+		}
+
+		return __orc_find(__start_orc_unwind_ip + start,
+				  __start_orc_unwind + start, stop - start, ip);
+	}
+
+	/* vmlinux .init slow lookup: */
+	if (is_kernel_inittext(ip))
+		return __orc_find(__start_orc_unwind_ip, __start_orc_unwind,
+				  __stop_orc_unwind_ip - __start_orc_unwind_ip, ip);
+
+	/* Module lookup: */
+	orc = orc_module_find(ip);
+	if (orc)
+		return orc;
+
+	orc =  orc_ftrace_find(ip);
+	if (orc)
+		return orc;
+
+	return orc_callthunk_find(ip);
+}
+
+#ifdef CONFIG_MODULES
+
+static DEFINE_MUTEX(sort_mutex);
+static int *cur_orc_ip_table = __start_orc_unwind_ip;
+static struct orc_entry *cur_orc_table = __start_orc_unwind;
+
+static void orc_sort_swap(void *_a, void *_b, int size)
+{
+	struct orc_entry *orc_a, *orc_b;
+	struct orc_entry orc_tmp;
+	int *a = _a, *b = _b, tmp;
+	int delta = _b - _a;
+
+	/* Swap the .orc_unwind_ip entries: */
+	tmp = *a;
+	*a = *b + delta;
+	*b = tmp - delta;
+
+	/* Swap the corresponding .orc_unwind entries: */
+	orc_a = cur_orc_table + (a - cur_orc_ip_table);
+	orc_b = cur_orc_table + (b - cur_orc_ip_table);
+	orc_tmp = *orc_a;
+	*orc_a = *orc_b;
+	*orc_b = orc_tmp;
+}
+
+static int orc_sort_cmp(const void *_a, const void *_b)
+{
+	struct orc_entry *orc_a;
+	const int *a = _a, *b = _b;
+	unsigned long a_val = orc_ip(a);
+	unsigned long b_val = orc_ip(b);
+
+	if (a_val > b_val)
+		return 1;
+	if (a_val < b_val)
+		return -1;
+
+	/*
+	 * The "weak" section terminator entries need to always be on the left
+	 * to ensure the lookup code skips them in favor of real entries.
+	 * These terminator entries exist to handle any gaps created by
+	 * whitelisted .o files which didn't get objtool generation.
+	 */
+	orc_a = cur_orc_table + (a - cur_orc_ip_table);
+	return orc_a->sp_reg == ORC_REG_UNDEFINED && !orc_a->end ? -1 : 1;
+}
+
+void unwind_module_init(struct module *mod, void *_orc_ip, size_t orc_ip_size,
+			void *_orc, size_t orc_size)
+{
+	int *orc_ip = _orc_ip;
+	struct orc_entry *orc = _orc;
+	unsigned int num_entries = orc_ip_size / sizeof(int);
+
+	WARN_ON_ONCE(orc_ip_size % sizeof(int) != 0 ||
+		     orc_size % sizeof(*orc) != 0 ||
+		     num_entries != orc_size / sizeof(*orc));
+
+	/*
+	 * The 'cur_orc_*' globals allow the orc_sort_swap() callback to
+	 * associate an .orc_unwind_ip table entry with its corresponding
+	 * .orc_unwind entry so they can both be swapped.
+	 */
+	mutex_lock(&sort_mutex);
+	cur_orc_ip_table = orc_ip;
+	cur_orc_table = orc;
+	sort(orc_ip, num_entries, sizeof(int), orc_sort_cmp, orc_sort_swap);
+	mutex_unlock(&sort_mutex);
+
+	mod->arch.orc_unwind_ip = orc_ip;
+	mod->arch.orc_unwind = orc;
+	mod->arch.num_orcs = num_entries;
+}
+#endif
+
+void __init unwind_init(void)
+{
+	size_t orc_ip_size = (void *)__stop_orc_unwind_ip - (void *)__start_orc_unwind_ip;
+	size_t orc_size = (void *)__stop_orc_unwind - (void *)__start_orc_unwind;
+	size_t num_entries = orc_ip_size / sizeof(int);
+	struct orc_entry *orc;
+	int i;
+
+	if (!num_entries || orc_ip_size % sizeof(int) != 0 ||
+	    orc_size % sizeof(struct orc_entry) != 0 ||
+	    num_entries != orc_size / sizeof(struct orc_entry)) {
+		orc_warn("WARNING: Bad or missing .orc_unwind table.  Disabling unwinder.\n");
+		return;
+	}
+
+	/*
+	 * Note, the orc_unwind and orc_unwind_ip tables were already
+	 * sorted at build time via the 'sorttable' tool.
+	 * It's ready for binary search straight away, no need to sort it.
+	 */
+
+	/* Initialize the fast lookup table: */
+	lookup_num_blocks = orc_lookup_end - orc_lookup;
+	for (i = 0; i < lookup_num_blocks-1; i++) {
+		orc = __orc_find(__start_orc_unwind_ip, __start_orc_unwind,
+				 num_entries,
+				 LOOKUP_START_IP + (LOOKUP_BLOCK_SIZE * i));
+		if (!orc) {
+			orc_warn("WARNING: Corrupt .orc_unwind table.  Disabling unwinder.\n");
+			return;
+		}
+
+		orc_lookup[i] = orc - __start_orc_unwind;
+	}
+
+	/* Initialize the ending block: */
+	orc = __orc_find(__start_orc_unwind_ip, __start_orc_unwind, num_entries,
+			 LOOKUP_STOP_IP);
+	if (!orc) {
+		orc_warn("WARNING: Corrupt .orc_unwind table.  Disabling unwinder.\n");
+		return;
+	}
+	orc_lookup[lookup_num_blocks-1] = orc - __start_orc_unwind;
+
+	orc_init = true;
+}
+
+unsigned long unwind_get_return_address(struct unwind_state *state)
+{
+	if (unwind_done(state))
+		return 0;
+
+	return __kernel_text_address(state->ip) ? state->ip : 0;
+}
+EXPORT_SYMBOL_GPL(unwind_get_return_address);
+
+unsigned long *unwind_get_return_address_ptr(struct unwind_state *state)
+{
+	if (unwind_done(state))
+		return NULL;
+
+	if (state->regs)
+		return &state->regs->ip;
+
+	if (state->sp)
+		return (unsigned long *)state->sp - 1;
+
+	return NULL;
+}
+
+static bool stack_access_ok(struct unwind_state *state, unsigned long _addr,
+			    size_t len)
+{
+	struct stack_info *info = &state->stack_info;
+	void *addr = (void *)_addr;
+
+	if (on_stack(info, addr, len))
+		return true;
+
+	return !get_stack_info(addr, state->task, info, &state->stack_mask) &&
+		on_stack(info, addr, len);
+}
+
+static bool deref_stack_reg(struct unwind_state *state, unsigned long addr,
+			    unsigned long *val)
+{
+	if (!stack_access_ok(state, addr, sizeof(long)))
+		return false;
+
+	*val = READ_ONCE_NOCHECK(*(unsigned long *)addr);
+	return true;
+}
+
+static bool deref_stack_regs(struct unwind_state *state, unsigned long addr,
+			     unsigned long *ip, unsigned long *sp)
+{
+	struct pt_regs *regs = (struct pt_regs *)addr;
+
+	/* x86-32 support will be more complicated due to the &regs->sp hack */
+	BUILD_BUG_ON(IS_ENABLED(CONFIG_X86_32));
+
+	if (!stack_access_ok(state, addr, sizeof(struct pt_regs)))
+		return false;
+
+	*ip = READ_ONCE_NOCHECK(regs->ip);
+	*sp = READ_ONCE_NOCHECK(regs->sp);
+	return true;
+}
+
+static bool deref_stack_iret_regs(struct unwind_state *state, unsigned long addr,
+				  unsigned long *ip, unsigned long *sp)
+{
+	struct pt_regs *regs = (void *)addr - IRET_FRAME_OFFSET;
+
+	if (!stack_access_ok(state, addr, IRET_FRAME_SIZE))
+		return false;
+
+	*ip = READ_ONCE_NOCHECK(regs->ip);
+	*sp = READ_ONCE_NOCHECK(regs->sp);
+	return true;
+}
+
+/*
+ * If state->regs is non-NULL, and points to a full pt_regs, just get the reg
+ * value from state->regs.
+ *
+ * Otherwise, if state->regs just points to IRET regs, and the previous frame
+ * had full regs, it's safe to get the value from the previous regs.  This can
+ * happen when early/late IRQ entry code gets interrupted by an NMI.
+ */
+static bool get_reg(struct unwind_state *state, unsigned int reg_off,
+		    unsigned long *val)
+{
+	unsigned int reg = reg_off/8;
+
+	if (!state->regs)
+		return false;
+
+	if (state->full_regs) {
+		*val = READ_ONCE_NOCHECK(((unsigned long *)state->regs)[reg]);
+		return true;
+	}
+
+	if (state->prev_regs) {
+		*val = READ_ONCE_NOCHECK(((unsigned long *)state->prev_regs)[reg]);
+		return true;
+	}
+
+	return false;
+}
+
+bool unwind_next_frame(struct unwind_state *state)
+{
+	unsigned long ip_p, sp, tmp, orig_ip = state->ip, prev_sp = state->sp;
+	enum stack_type prev_type = state->stack_info.type;
+	struct orc_entry *orc;
+	bool indirect = false;
+
+	if (unwind_done(state))
+		return false;
+
+	/* Don't let modules unload while we're reading their ORC data. */
+	preempt_disable();
+
+	/* End-of-stack check for user tasks: */
+	if (state->regs && user_mode(state->regs))
+		goto the_end;
+
+	/*
+	 * Find the orc_entry associated with the text address.
+	 *
+	 * For a call frame (as opposed to a signal frame), state->ip points to
+	 * the instruction after the call.  That instruction's stack layout
+	 * could be different from the call instruction's layout, for example
+	 * if the call was to a noreturn function.  So get the ORC data for the
+	 * call instruction itself.
+	 */
+	orc = orc_find(state->signal ? state->ip : state->ip - 1);
+	if (!orc) {
+		/*
+		 * As a fallback, try to assume this code uses a frame pointer.
+		 * This is useful for generated code, like BPF, which ORC
+		 * doesn't know about.  This is just a guess, so the rest of
+		 * the unwind is no longer considered reliable.
+		 */
+		orc = &orc_fp_entry;
+		state->error = true;
+	}
+
+	/* End-of-stack check for kernel threads: */
+	if (orc->sp_reg == ORC_REG_UNDEFINED) {
+		if (!orc->end)
+			goto err;
+
+		goto the_end;
+	}
+
+	/* Find the previous frame's stack: */
+	switch (orc->sp_reg) {
+	case ORC_REG_SP:
+		sp = state->sp + orc->sp_offset;
+		break;
+
+	case ORC_REG_BP:
+		sp = state->bp + orc->sp_offset;
+		break;
+
+	case ORC_REG_SP_INDIRECT:
+		sp = state->sp;
+		indirect = true;
+		break;
+
+	case ORC_REG_BP_INDIRECT:
+		sp = state->bp + orc->sp_offset;
+		indirect = true;
+		break;
+
+	case ORC_REG_R10:
+		if (!get_reg(state, offsetof(struct pt_regs, r10), &sp)) {
+			orc_warn_current("missing R10 value at %pB\n",
+					 (void *)state->ip);
+			goto err;
+		}
+		break;
+
+	case ORC_REG_R13:
+		if (!get_reg(state, offsetof(struct pt_regs, r13), &sp)) {
+			orc_warn_current("missing R13 value at %pB\n",
+					 (void *)state->ip);
+			goto err;
+		}
+		break;
+
+	case ORC_REG_DI:
+		if (!get_reg(state, offsetof(struct pt_regs, di), &sp)) {
+			orc_warn_current("missing RDI value at %pB\n",
+					 (void *)state->ip);
+			goto err;
+		}
+		break;
+
+	case ORC_REG_DX:
+		if (!get_reg(state, offsetof(struct pt_regs, dx), &sp)) {
+			orc_warn_current("missing DX value at %pB\n",
+					 (void *)state->ip);
+			goto err;
+		}
+		break;
+
+	default:
+		orc_warn("unknown SP base reg %d at %pB\n",
+			 orc->sp_reg, (void *)state->ip);
+		goto err;
+	}
+
+	if (indirect) {
+		if (!deref_stack_reg(state, sp, &sp))
+			goto err;
+
+		if (orc->sp_reg == ORC_REG_SP_INDIRECT)
+			sp += orc->sp_offset;
+	}
+
+	/* Find IP, SP and possibly regs: */
+	switch (orc->type) {
+	case UNWIND_HINT_TYPE_CALL:
+		ip_p = sp - sizeof(long);
+
+		if (!deref_stack_reg(state, ip_p, &state->ip))
+			goto err;
+
+		state->ip = unwind_recover_ret_addr(state, state->ip,
+						    (unsigned long *)ip_p);
+		state->sp = sp;
+		state->regs = NULL;
+		state->prev_regs = NULL;
+		state->signal = false;
+		break;
+
+	case UNWIND_HINT_TYPE_REGS:
+		if (!deref_stack_regs(state, sp, &state->ip, &state->sp)) {
+			orc_warn_current("can't access registers at %pB\n",
+					 (void *)orig_ip);
+			goto err;
+		}
+		/*
+		 * There is a small chance to interrupt at the entry of
+		 * arch_rethook_trampoline() where the ORC info doesn't exist.
+		 * That point is right after the RET to arch_rethook_trampoline()
+		 * which was modified return address.
+		 * At that point, the @addr_p of the unwind_recover_rethook()
+		 * (this has to point the address of the stack entry storing
+		 * the modified return address) must be "SP - (a stack entry)"
+		 * because SP is incremented by the RET.
+		 */
+		state->ip = unwind_recover_rethook(state, state->ip,
+				(unsigned long *)(state->sp - sizeof(long)));
+		state->regs = (struct pt_regs *)sp;
+		state->prev_regs = NULL;
+		state->full_regs = true;
+		state->signal = true;
+		break;
+
+	case UNWIND_HINT_TYPE_REGS_PARTIAL:
+		if (!deref_stack_iret_regs(state, sp, &state->ip, &state->sp)) {
+			orc_warn_current("can't access iret registers at %pB\n",
+					 (void *)orig_ip);
+			goto err;
+		}
+		/* See UNWIND_HINT_TYPE_REGS case comment. */
+		state->ip = unwind_recover_rethook(state, state->ip,
+				(unsigned long *)(state->sp - sizeof(long)));
+
+		if (state->full_regs)
+			state->prev_regs = state->regs;
+		state->regs = (void *)sp - IRET_FRAME_OFFSET;
+		state->full_regs = false;
+		state->signal = true;
+		break;
+
+	default:
+		orc_warn("unknown .orc_unwind entry type %d at %pB\n",
+			 orc->type, (void *)orig_ip);
+		goto err;
+	}
+
+	/* Find BP: */
+	switch (orc->bp_reg) {
+	case ORC_REG_UNDEFINED:
+		if (get_reg(state, offsetof(struct pt_regs, bp), &tmp))
+			state->bp = tmp;
+		break;
+
+	case ORC_REG_PREV_SP:
+		if (!deref_stack_reg(state, sp + orc->bp_offset, &state->bp))
+			goto err;
+		break;
+
+	case ORC_REG_BP:
+		if (!deref_stack_reg(state, state->bp + orc->bp_offset, &state->bp))
+			goto err;
+		break;
+
+	default:
+		orc_warn("unknown BP base reg %d for ip %pB\n",
+			 orc->bp_reg, (void *)orig_ip);
+		goto err;
+	}
+
+	/* Prevent a recursive loop due to bad ORC data: */
+	if (state->stack_info.type == prev_type &&
+	    on_stack(&state->stack_info, (void *)state->sp, sizeof(long)) &&
+	    state->sp <= prev_sp) {
+		orc_warn_current("stack going in the wrong direction? at %pB\n",
+				 (void *)orig_ip);
+		goto err;
+	}
+
+	preempt_enable();
+	return true;
+
+err:
+	state->error = true;
+
+the_end:
+	preempt_enable();
+	state->stack_info.type = STACK_TYPE_UNKNOWN;
+	return false;
+}
+EXPORT_SYMBOL_GPL(unwind_next_frame);
+
+void __unwind_start(struct unwind_state *state, struct task_struct *task,
+		    struct pt_regs *regs, unsigned long *first_frame)
+{
+	memset(state, 0, sizeof(*state));
+	state->task = task;
+
+	if (!orc_init)
+		goto err;
+
+	/*
+	 * Refuse to unwind the stack of a task while it's executing on another
+	 * CPU.  This check is racy, but that's ok: the unwinder has other
+	 * checks to prevent it from going off the rails.
+	 */
+	if (task_on_another_cpu(task))
+		goto err;
+
+	if (regs) {
+		if (user_mode(regs))
+			goto the_end;
+
+		state->ip = regs->ip;
+		state->sp = regs->sp;
+		state->bp = regs->bp;
+		state->regs = regs;
+		state->full_regs = true;
+		state->signal = true;
+
+	} else if (task == current) {
+		asm volatile("lea (%%rip), %0\n\t"
+			     "mov %%rsp, %1\n\t"
+			     "mov %%rbp, %2\n\t"
+			     : "=r" (state->ip), "=r" (state->sp),
+			       "=r" (state->bp));
+
+	} else {
+		struct inactive_task_frame *frame = (void *)task->thread.sp;
+
+		state->sp = task->thread.sp + sizeof(*frame);
+		state->bp = READ_ONCE_NOCHECK(frame->bp);
+		state->ip = READ_ONCE_NOCHECK(frame->ret_addr);
+		state->signal = (void *)state->ip == ret_from_fork;
+	}
+
+	if (get_stack_info((unsigned long *)state->sp, state->task,
+			   &state->stack_info, &state->stack_mask)) {
+		/*
+		 * We weren't on a valid stack.  It's possible that
+		 * we overflowed a valid stack into a guard page.
+		 * See if the next page up is valid so that we can
+		 * generate some kind of backtrace if this happens.
+		 */
+		void *next_page = (void *)PAGE_ALIGN((unsigned long)state->sp);
+		state->error = true;
+		if (get_stack_info(next_page, state->task, &state->stack_info,
+				   &state->stack_mask))
+			return;
+	}
+
+	/*
+	 * The caller can provide the address of the first frame directly
+	 * (first_frame) or indirectly (regs->sp) to indicate which stack frame
+	 * to start unwinding at.  Skip ahead until we reach it.
+	 */
+
+	/* When starting from regs, skip the regs frame: */
+	if (regs) {
+		unwind_next_frame(state);
+		return;
+	}
+
+	/* Otherwise, skip ahead to the user-specified starting frame: */
+	while (!unwind_done(state) &&
+	       (!on_stack(&state->stack_info, first_frame, sizeof(long)) ||
+			state->sp <= (unsigned long)first_frame))
+		unwind_next_frame(state);
+
+	return;
+
+err:
+	state->error = true;
+the_end:
+	state->stack_info.type = STACK_TYPE_UNKNOWN;
+}
+EXPORT_SYMBOL_GPL(__unwind_start);