From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 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(). ... --- arch/arm/kernel/unwind.c | 585 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 585 insertions(+) create mode 100644 arch/arm/kernel/unwind.c (limited to 'arch/arm/kernel/unwind.c') diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c new file mode 100644 index 000000000..53be7ea61 --- /dev/null +++ b/arch/arm/kernel/unwind.c @@ -0,0 +1,585 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * arch/arm/kernel/unwind.c + * + * Copyright (C) 2008 ARM Limited + * + * Stack unwinding support for ARM + * + * An ARM EABI version of gcc is required to generate the unwind + * tables. For information about the structure of the unwind tables, + * see "Exception Handling ABI for the ARM Architecture" at: + * + * http://infocenter.arm.com/help/topic/com.arm.doc.subset.swdev.abi/index.html + */ + +#ifndef __CHECKER__ +#if !defined (__ARM_EABI__) +#warning Your compiler does not have EABI support. +#warning ARM unwind is known to compile only with EABI compilers. +#warning Change compiler or disable ARM_UNWIND option. +#endif +#endif /* __CHECKER__ */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include "reboot.h" + +/* Dummy functions to avoid linker complaints */ +void __aeabi_unwind_cpp_pr0(void) +{ +}; +EXPORT_SYMBOL(__aeabi_unwind_cpp_pr0); + +void __aeabi_unwind_cpp_pr1(void) +{ +}; +EXPORT_SYMBOL(__aeabi_unwind_cpp_pr1); + +void __aeabi_unwind_cpp_pr2(void) +{ +}; +EXPORT_SYMBOL(__aeabi_unwind_cpp_pr2); + +struct unwind_ctrl_block { + unsigned long vrs[16]; /* virtual register set */ + const unsigned long *insn; /* pointer to the current instructions word */ + unsigned long sp_high; /* highest value of sp allowed */ + unsigned long *lr_addr; /* address of LR value on the stack */ + /* + * 1 : check for stack overflow for each register pop. + * 0 : save overhead if there is plenty of stack remaining. + */ + int check_each_pop; + int entries; /* number of entries left to interpret */ + int byte; /* current byte number in the instructions word */ +}; + +enum regs { +#ifdef CONFIG_THUMB2_KERNEL + FP = 7, +#else + FP = 11, +#endif + SP = 13, + LR = 14, + PC = 15 +}; + +extern const struct unwind_idx __start_unwind_idx[]; +static const struct unwind_idx *__origin_unwind_idx; +extern const struct unwind_idx __stop_unwind_idx[]; + +static DEFINE_RAW_SPINLOCK(unwind_lock); +static LIST_HEAD(unwind_tables); + +/* Convert a prel31 symbol to an absolute address */ +#define prel31_to_addr(ptr) \ +({ \ + /* sign-extend to 32 bits */ \ + long offset = (((long)*(ptr)) << 1) >> 1; \ + (unsigned long)(ptr) + offset; \ +}) + +/* + * Binary search in the unwind index. The entries are + * guaranteed to be sorted in ascending order by the linker. + * + * start = first entry + * origin = first entry with positive offset (or stop if there is no such entry) + * stop - 1 = last entry + */ +static const struct unwind_idx *search_index(unsigned long addr, + const struct unwind_idx *start, + const struct unwind_idx *origin, + const struct unwind_idx *stop) +{ + unsigned long addr_prel31; + + pr_debug("%s(%08lx, %p, %p, %p)\n", + __func__, addr, start, origin, stop); + + /* + * only search in the section with the matching sign. This way the + * prel31 numbers can be compared as unsigned longs. + */ + if (addr < (unsigned long)start) + /* negative offsets: [start; origin) */ + stop = origin; + else + /* positive offsets: [origin; stop) */ + start = origin; + + /* prel31 for address relavive to start */ + addr_prel31 = (addr - (unsigned long)start) & 0x7fffffff; + + while (start < stop - 1) { + const struct unwind_idx *mid = start + ((stop - start) >> 1); + + /* + * As addr_prel31 is relative to start an offset is needed to + * make it relative to mid. + */ + if (addr_prel31 - ((unsigned long)mid - (unsigned long)start) < + mid->addr_offset) + stop = mid; + else { + /* keep addr_prel31 relative to start */ + addr_prel31 -= ((unsigned long)mid - + (unsigned long)start); + start = mid; + } + } + + if (likely(start->addr_offset <= addr_prel31)) + return start; + else { + pr_warn("unwind: Unknown symbol address %08lx\n", addr); + return NULL; + } +} + +static const struct unwind_idx *unwind_find_origin( + const struct unwind_idx *start, const struct unwind_idx *stop) +{ + pr_debug("%s(%p, %p)\n", __func__, start, stop); + while (start < stop) { + const struct unwind_idx *mid = start + ((stop - start) >> 1); + + if (mid->addr_offset >= 0x40000000) + /* negative offset */ + start = mid + 1; + else + /* positive offset */ + stop = mid; + } + pr_debug("%s -> %p\n", __func__, stop); + return stop; +} + +static const struct unwind_idx *unwind_find_idx(unsigned long addr) +{ + const struct unwind_idx *idx = NULL; + unsigned long flags; + + pr_debug("%s(%08lx)\n", __func__, addr); + + if (core_kernel_text(addr)) { + if (unlikely(!__origin_unwind_idx)) + __origin_unwind_idx = + unwind_find_origin(__start_unwind_idx, + __stop_unwind_idx); + + /* main unwind table */ + idx = search_index(addr, __start_unwind_idx, + __origin_unwind_idx, + __stop_unwind_idx); + } else { + /* module unwind tables */ + struct unwind_table *table; + + raw_spin_lock_irqsave(&unwind_lock, flags); + list_for_each_entry(table, &unwind_tables, list) { + if (addr >= table->begin_addr && + addr < table->end_addr) { + idx = search_index(addr, table->start, + table->origin, + table->stop); + /* Move-to-front to exploit common traces */ + list_move(&table->list, &unwind_tables); + break; + } + } + raw_spin_unlock_irqrestore(&unwind_lock, flags); + } + + pr_debug("%s: idx = %p\n", __func__, idx); + return idx; +} + +static unsigned long unwind_get_byte(struct unwind_ctrl_block *ctrl) +{ + unsigned long ret; + + if (ctrl->entries <= 0) { + pr_warn("unwind: Corrupt unwind table\n"); + return 0; + } + + ret = (*ctrl->insn >> (ctrl->byte * 8)) & 0xff; + + if (ctrl->byte == 0) { + ctrl->insn++; + ctrl->entries--; + ctrl->byte = 3; + } else + ctrl->byte--; + + return ret; +} + +/* Before poping a register check whether it is feasible or not */ +static int unwind_pop_register(struct unwind_ctrl_block *ctrl, + unsigned long **vsp, unsigned int reg) +{ + if (unlikely(ctrl->check_each_pop)) + if (*vsp >= (unsigned long *)ctrl->sp_high) + return -URC_FAILURE; + + /* Use READ_ONCE_NOCHECK here to avoid this memory access + * from being tracked by KASAN. + */ + ctrl->vrs[reg] = READ_ONCE_NOCHECK(*(*vsp)); + if (reg == 14) + ctrl->lr_addr = *vsp; + (*vsp)++; + return URC_OK; +} + +/* Helper functions to execute the instructions */ +static int unwind_exec_pop_subset_r4_to_r13(struct unwind_ctrl_block *ctrl, + unsigned long mask) +{ + unsigned long *vsp = (unsigned long *)ctrl->vrs[SP]; + int load_sp, reg = 4; + + load_sp = mask & (1 << (13 - 4)); + while (mask) { + if (mask & 1) + if (unwind_pop_register(ctrl, &vsp, reg)) + return -URC_FAILURE; + mask >>= 1; + reg++; + } + if (!load_sp) { + ctrl->vrs[SP] = (unsigned long)vsp; + } + + return URC_OK; +} + +static int unwind_exec_pop_r4_to_rN(struct unwind_ctrl_block *ctrl, + unsigned long insn) +{ + unsigned long *vsp = (unsigned long *)ctrl->vrs[SP]; + int reg; + + /* pop R4-R[4+bbb] */ + for (reg = 4; reg <= 4 + (insn & 7); reg++) + if (unwind_pop_register(ctrl, &vsp, reg)) + return -URC_FAILURE; + + if (insn & 0x8) + if (unwind_pop_register(ctrl, &vsp, 14)) + return -URC_FAILURE; + + ctrl->vrs[SP] = (unsigned long)vsp; + + return URC_OK; +} + +static int unwind_exec_pop_subset_r0_to_r3(struct unwind_ctrl_block *ctrl, + unsigned long mask) +{ + unsigned long *vsp = (unsigned long *)ctrl->vrs[SP]; + int reg = 0; + + /* pop R0-R3 according to mask */ + while (mask) { + if (mask & 1) + if (unwind_pop_register(ctrl, &vsp, reg)) + return -URC_FAILURE; + mask >>= 1; + reg++; + } + ctrl->vrs[SP] = (unsigned long)vsp; + + return URC_OK; +} + +/* + * Execute the current unwind instruction. + */ +static int unwind_exec_insn(struct unwind_ctrl_block *ctrl) +{ + unsigned long insn = unwind_get_byte(ctrl); + int ret = URC_OK; + + pr_debug("%s: insn = %08lx\n", __func__, insn); + + if ((insn & 0xc0) == 0x00) + ctrl->vrs[SP] += ((insn & 0x3f) << 2) + 4; + else if ((insn & 0xc0) == 0x40) { + ctrl->vrs[SP] -= ((insn & 0x3f) << 2) + 4; + } else if ((insn & 0xf0) == 0x80) { + unsigned long mask; + + insn = (insn << 8) | unwind_get_byte(ctrl); + mask = insn & 0x0fff; + if (mask == 0) { + pr_warn("unwind: 'Refuse to unwind' instruction %04lx\n", + insn); + return -URC_FAILURE; + } + + ret = unwind_exec_pop_subset_r4_to_r13(ctrl, mask); + if (ret) + goto error; + } else if ((insn & 0xf0) == 0x90 && + (insn & 0x0d) != 0x0d) { + ctrl->vrs[SP] = ctrl->vrs[insn & 0x0f]; + } else if ((insn & 0xf0) == 0xa0) { + ret = unwind_exec_pop_r4_to_rN(ctrl, insn); + if (ret) + goto error; + } else if (insn == 0xb0) { + if (ctrl->vrs[PC] == 0) + ctrl->vrs[PC] = ctrl->vrs[LR]; + /* no further processing */ + ctrl->entries = 0; + } else if (insn == 0xb1) { + unsigned long mask = unwind_get_byte(ctrl); + + if (mask == 0 || mask & 0xf0) { + pr_warn("unwind: Spare encoding %04lx\n", + (insn << 8) | mask); + return -URC_FAILURE; + } + + ret = unwind_exec_pop_subset_r0_to_r3(ctrl, mask); + if (ret) + goto error; + } else if (insn == 0xb2) { + unsigned long uleb128 = unwind_get_byte(ctrl); + + ctrl->vrs[SP] += 0x204 + (uleb128 << 2); + } else { + pr_warn("unwind: Unhandled instruction %02lx\n", insn); + return -URC_FAILURE; + } + + pr_debug("%s: fp = %08lx sp = %08lx lr = %08lx pc = %08lx\n", __func__, + ctrl->vrs[FP], ctrl->vrs[SP], ctrl->vrs[LR], ctrl->vrs[PC]); + +error: + return ret; +} + +/* + * Unwind a single frame starting with *sp for the symbol at *pc. It + * updates the *pc and *sp with the new values. + */ +int unwind_frame(struct stackframe *frame) +{ + const struct unwind_idx *idx; + struct unwind_ctrl_block ctrl; + unsigned long sp_low; + + /* store the highest address on the stack to avoid crossing it*/ + sp_low = frame->sp; + ctrl.sp_high = ALIGN(sp_low - THREAD_SIZE, THREAD_ALIGN) + + THREAD_SIZE; + + pr_debug("%s(pc = %08lx lr = %08lx sp = %08lx)\n", __func__, + frame->pc, frame->lr, frame->sp); + + idx = unwind_find_idx(frame->pc); + if (!idx) { + if (frame->pc && kernel_text_address(frame->pc)) { + if (in_module_plt(frame->pc) && frame->pc != frame->lr) { + /* + * Quoting Ard: Veneers only set PC using a + * PC+immediate LDR, and so they don't affect + * the state of the stack or the register file + */ + frame->pc = frame->lr; + return URC_OK; + } + pr_warn("unwind: Index not found %08lx\n", frame->pc); + } + return -URC_FAILURE; + } + + ctrl.vrs[FP] = frame->fp; + ctrl.vrs[SP] = frame->sp; + ctrl.vrs[LR] = frame->lr; + ctrl.vrs[PC] = 0; + + if (idx->insn == 1) + /* can't unwind */ + return -URC_FAILURE; + else if (frame->pc == prel31_to_addr(&idx->addr_offset)) { + /* + * Unwinding is tricky when we're halfway through the prologue, + * since the stack frame that the unwinder expects may not be + * fully set up yet. However, one thing we do know for sure is + * that if we are unwinding from the very first instruction of + * a function, we are still effectively in the stack frame of + * the caller, and the unwind info has no relevance yet. + */ + if (frame->pc == frame->lr) + return -URC_FAILURE; + frame->pc = frame->lr; + return URC_OK; + } else if ((idx->insn & 0x80000000) == 0) + /* prel31 to the unwind table */ + ctrl.insn = (unsigned long *)prel31_to_addr(&idx->insn); + else if ((idx->insn & 0xff000000) == 0x80000000) + /* only personality routine 0 supported in the index */ + ctrl.insn = &idx->insn; + else { + pr_warn("unwind: Unsupported personality routine %08lx in the index at %p\n", + idx->insn, idx); + return -URC_FAILURE; + } + + /* check the personality routine */ + if ((*ctrl.insn & 0xff000000) == 0x80000000) { + ctrl.byte = 2; + ctrl.entries = 1; + } else if ((*ctrl.insn & 0xff000000) == 0x81000000) { + ctrl.byte = 1; + ctrl.entries = 1 + ((*ctrl.insn & 0x00ff0000) >> 16); + } else { + pr_warn("unwind: Unsupported personality routine %08lx at %p\n", + *ctrl.insn, ctrl.insn); + return -URC_FAILURE; + } + + ctrl.check_each_pop = 0; + + if (prel31_to_addr(&idx->addr_offset) == (u32)&call_with_stack) { + /* + * call_with_stack() is the only place where we permit SP to + * jump from one stack to another, and since we know it is + * guaranteed to happen, set up the SP bounds accordingly. + */ + sp_low = frame->fp; + ctrl.sp_high = ALIGN(frame->fp, THREAD_SIZE); + } + + while (ctrl.entries > 0) { + int urc; + if ((ctrl.sp_high - ctrl.vrs[SP]) < sizeof(ctrl.vrs)) + ctrl.check_each_pop = 1; + urc = unwind_exec_insn(&ctrl); + if (urc < 0) + return urc; + if (ctrl.vrs[SP] < sp_low || ctrl.vrs[SP] > ctrl.sp_high) + return -URC_FAILURE; + } + + if (ctrl.vrs[PC] == 0) + ctrl.vrs[PC] = ctrl.vrs[LR]; + + /* check for infinite loop */ + if (frame->pc == ctrl.vrs[PC] && frame->sp == ctrl.vrs[SP]) + return -URC_FAILURE; + + frame->fp = ctrl.vrs[FP]; + frame->sp = ctrl.vrs[SP]; + frame->lr = ctrl.vrs[LR]; + frame->pc = ctrl.vrs[PC]; + frame->lr_addr = ctrl.lr_addr; + + return URC_OK; +} + +void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk, + const char *loglvl) +{ + struct stackframe frame; + + pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk); + + if (!tsk) + tsk = current; + + if (regs) { + arm_get_current_stackframe(regs, &frame); + /* PC might be corrupted, use LR in that case. */ + if (!kernel_text_address(regs->ARM_pc)) + frame.pc = regs->ARM_lr; + } else if (tsk == current) { + frame.fp = (unsigned long)__builtin_frame_address(0); + frame.sp = current_stack_pointer; + frame.lr = (unsigned long)__builtin_return_address(0); + /* We are saving the stack and execution state at this + * point, so we should ensure that frame.pc is within + * this block of code. + */ +here: + frame.pc = (unsigned long)&&here; + } else { + /* task blocked in __switch_to */ + frame.fp = thread_saved_fp(tsk); + frame.sp = thread_saved_sp(tsk); + /* + * The function calling __switch_to cannot be a leaf function + * so LR is recovered from the stack. + */ + frame.lr = 0; + frame.pc = thread_saved_pc(tsk); + } + + while (1) { + int urc; + unsigned long where = frame.pc; + + urc = unwind_frame(&frame); + if (urc < 0) + break; + dump_backtrace_entry(where, frame.pc, frame.sp - 4, loglvl); + } +} + +struct unwind_table *unwind_table_add(unsigned long start, unsigned long size, + unsigned long text_addr, + unsigned long text_size) +{ + unsigned long flags; + struct unwind_table *tab = kmalloc(sizeof(*tab), GFP_KERNEL); + + pr_debug("%s(%08lx, %08lx, %08lx, %08lx)\n", __func__, start, size, + text_addr, text_size); + + if (!tab) + return tab; + + tab->start = (const struct unwind_idx *)start; + tab->stop = (const struct unwind_idx *)(start + size); + tab->origin = unwind_find_origin(tab->start, tab->stop); + tab->begin_addr = text_addr; + tab->end_addr = text_addr + text_size; + + raw_spin_lock_irqsave(&unwind_lock, flags); + list_add_tail(&tab->list, &unwind_tables); + raw_spin_unlock_irqrestore(&unwind_lock, flags); + + return tab; +} + +void unwind_table_del(struct unwind_table *tab) +{ + unsigned long flags; + + if (!tab) + return; + + raw_spin_lock_irqsave(&unwind_lock, flags); + list_del(&tab->list); + raw_spin_unlock_irqrestore(&unwind_lock, flags); + + kfree(tab); +} -- cgit v1.2.3