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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /arch/mips/kernel/process.c | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
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().
...
Diffstat (limited to 'arch/mips/kernel/process.c')
-rw-r--r-- | arch/mips/kernel/process.c | 911 |
1 files changed, 911 insertions, 0 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c new file mode 100644 index 000000000..093dbbd6b --- /dev/null +++ b/arch/mips/kernel/process.c @@ -0,0 +1,911 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others. + * Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org) + * Copyright (C) 1999, 2000 Silicon Graphics, Inc. + * Copyright (C) 2004 Thiemo Seufer + * Copyright (C) 2013 Imagination Technologies Ltd. + */ +#include <linux/cpu.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/kallsyms.h> +#include <linux/kernel.h> +#include <linux/nmi.h> +#include <linux/personality.h> +#include <linux/prctl.h> +#include <linux/random.h> +#include <linux/sched.h> +#include <linux/sched/debug.h> +#include <linux/sched/task_stack.h> + +#include <asm/abi.h> +#include <asm/asm.h> +#include <asm/dsemul.h> +#include <asm/dsp.h> +#include <asm/exec.h> +#include <asm/fpu.h> +#include <asm/inst.h> +#include <asm/irq.h> +#include <asm/irq_regs.h> +#include <asm/isadep.h> +#include <asm/msa.h> +#include <asm/mips-cps.h> +#include <asm/mipsregs.h> +#include <asm/processor.h> +#include <asm/reg.h> +#include <asm/stacktrace.h> + +#ifdef CONFIG_HOTPLUG_CPU +void arch_cpu_idle_dead(void) +{ + play_dead(); +} +#endif + +asmlinkage void ret_from_fork(void); +asmlinkage void ret_from_kernel_thread(void); + +void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp) +{ + unsigned long status; + + /* New thread loses kernel privileges. */ + status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_CU2|ST0_FR|KU_MASK); + status |= KU_USER; + regs->cp0_status = status; + lose_fpu(0); + clear_thread_flag(TIF_MSA_CTX_LIVE); + clear_used_math(); +#ifdef CONFIG_MIPS_FP_SUPPORT + atomic_set(¤t->thread.bd_emu_frame, BD_EMUFRAME_NONE); +#endif + init_dsp(); + regs->cp0_epc = pc; + regs->regs[29] = sp; +} + +void exit_thread(struct task_struct *tsk) +{ + /* + * User threads may have allocated a delay slot emulation frame. + * If so, clean up that allocation. + */ + if (!(current->flags & PF_KTHREAD)) + dsemul_thread_cleanup(tsk); +} + +int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) +{ + /* + * Save any process state which is live in hardware registers to the + * parent context prior to duplication. This prevents the new child + * state becoming stale if the parent is preempted before copy_thread() + * gets a chance to save the parent's live hardware registers to the + * child context. + */ + preempt_disable(); + + if (is_msa_enabled()) + save_msa(current); + else if (is_fpu_owner()) + _save_fp(current); + + save_dsp(current); + + preempt_enable(); + + *dst = *src; + return 0; +} + +/* + * Copy architecture-specific thread state + */ +int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) +{ + unsigned long clone_flags = args->flags; + unsigned long usp = args->stack; + unsigned long tls = args->tls; + struct thread_info *ti = task_thread_info(p); + struct pt_regs *childregs, *regs = current_pt_regs(); + unsigned long childksp; + + childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32; + + /* set up new TSS. */ + childregs = (struct pt_regs *) childksp - 1; + /* Put the stack after the struct pt_regs. */ + childksp = (unsigned long) childregs; + p->thread.cp0_status = (read_c0_status() & ~(ST0_CU2|ST0_CU1)) | ST0_KERNEL_CUMASK; + if (unlikely(args->fn)) { + /* kernel thread */ + unsigned long status = p->thread.cp0_status; + memset(childregs, 0, sizeof(struct pt_regs)); + p->thread.reg16 = (unsigned long)args->fn; + p->thread.reg17 = (unsigned long)args->fn_arg; + p->thread.reg29 = childksp; + p->thread.reg31 = (unsigned long) ret_from_kernel_thread; +#if defined(CONFIG_CPU_R3000) + status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) | + ((status & (ST0_KUC | ST0_IEC)) << 2); +#else + status |= ST0_EXL; +#endif + childregs->cp0_status = status; + return 0; + } + + /* user thread */ + *childregs = *regs; + childregs->regs[7] = 0; /* Clear error flag */ + childregs->regs[2] = 0; /* Child gets zero as return value */ + if (usp) + childregs->regs[29] = usp; + + p->thread.reg29 = (unsigned long) childregs; + p->thread.reg31 = (unsigned long) ret_from_fork; + + /* + * New tasks lose permission to use the fpu. This accelerates context + * switching for most programs since they don't use the fpu. + */ + childregs->cp0_status &= ~(ST0_CU2|ST0_CU1); + + clear_tsk_thread_flag(p, TIF_USEDFPU); + clear_tsk_thread_flag(p, TIF_USEDMSA); + clear_tsk_thread_flag(p, TIF_MSA_CTX_LIVE); + +#ifdef CONFIG_MIPS_MT_FPAFF + clear_tsk_thread_flag(p, TIF_FPUBOUND); +#endif /* CONFIG_MIPS_MT_FPAFF */ + +#ifdef CONFIG_MIPS_FP_SUPPORT + atomic_set(&p->thread.bd_emu_frame, BD_EMUFRAME_NONE); +#endif + + if (clone_flags & CLONE_SETTLS) + ti->tp_value = tls; + + return 0; +} + +#ifdef CONFIG_STACKPROTECTOR +#include <linux/stackprotector.h> +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); +#endif + +struct mips_frame_info { + void *func; + unsigned long func_size; + int frame_size; + int pc_offset; +}; + +#define J_TARGET(pc,target) \ + (((unsigned long)(pc) & 0xf0000000) | ((target) << 2)) + +static inline int is_jr_ra_ins(union mips_instruction *ip) +{ +#ifdef CONFIG_CPU_MICROMIPS + /* + * jr16 ra + * jr ra + */ + if (mm_insn_16bit(ip->word >> 16)) { + if (ip->mm16_r5_format.opcode == mm_pool16c_op && + ip->mm16_r5_format.rt == mm_jr16_op && + ip->mm16_r5_format.imm == 31) + return 1; + return 0; + } + + if (ip->r_format.opcode == mm_pool32a_op && + ip->r_format.func == mm_pool32axf_op && + ((ip->u_format.uimmediate >> 6) & GENMASK(9, 0)) == mm_jalr_op && + ip->r_format.rt == 31) + return 1; + return 0; +#else + if (ip->r_format.opcode == spec_op && + ip->r_format.func == jr_op && + ip->r_format.rs == 31) + return 1; + return 0; +#endif +} + +static inline int is_ra_save_ins(union mips_instruction *ip, int *poff) +{ +#ifdef CONFIG_CPU_MICROMIPS + /* + * swsp ra,offset + * swm16 reglist,offset(sp) + * swm32 reglist,offset(sp) + * sw32 ra,offset(sp) + * jradiussp - NOT SUPPORTED + * + * microMIPS is way more fun... + */ + if (mm_insn_16bit(ip->word >> 16)) { + switch (ip->mm16_r5_format.opcode) { + case mm_swsp16_op: + if (ip->mm16_r5_format.rt != 31) + return 0; + + *poff = ip->mm16_r5_format.imm; + *poff = (*poff << 2) / sizeof(ulong); + return 1; + + case mm_pool16c_op: + switch (ip->mm16_m_format.func) { + case mm_swm16_op: + *poff = ip->mm16_m_format.imm; + *poff += 1 + ip->mm16_m_format.rlist; + *poff = (*poff << 2) / sizeof(ulong); + return 1; + + default: + return 0; + } + + default: + return 0; + } + } + + switch (ip->i_format.opcode) { + case mm_sw32_op: + if (ip->i_format.rs != 29) + return 0; + if (ip->i_format.rt != 31) + return 0; + + *poff = ip->i_format.simmediate / sizeof(ulong); + return 1; + + case mm_pool32b_op: + switch (ip->mm_m_format.func) { + case mm_swm32_func: + if (ip->mm_m_format.rd < 0x10) + return 0; + if (ip->mm_m_format.base != 29) + return 0; + + *poff = ip->mm_m_format.simmediate; + *poff += (ip->mm_m_format.rd & 0xf) * sizeof(u32); + *poff /= sizeof(ulong); + return 1; + default: + return 0; + } + + default: + return 0; + } +#else + /* sw / sd $ra, offset($sp) */ + if ((ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) && + ip->i_format.rs == 29 && ip->i_format.rt == 31) { + *poff = ip->i_format.simmediate / sizeof(ulong); + return 1; + } +#ifdef CONFIG_CPU_LOONGSON64 + if ((ip->loongson3_lswc2_format.opcode == swc2_op) && + (ip->loongson3_lswc2_format.ls == 1) && + (ip->loongson3_lswc2_format.fr == 0) && + (ip->loongson3_lswc2_format.base == 29)) { + if (ip->loongson3_lswc2_format.rt == 31) { + *poff = ip->loongson3_lswc2_format.offset << 1; + return 1; + } + if (ip->loongson3_lswc2_format.rq == 31) { + *poff = (ip->loongson3_lswc2_format.offset << 1) + 1; + return 1; + } + } +#endif + return 0; +#endif +} + +static inline int is_jump_ins(union mips_instruction *ip) +{ +#ifdef CONFIG_CPU_MICROMIPS + /* + * jr16,jrc,jalr16,jalr16 + * jal + * jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb + * jraddiusp - NOT SUPPORTED + * + * microMIPS is kind of more fun... + */ + if (mm_insn_16bit(ip->word >> 16)) { + if ((ip->mm16_r5_format.opcode == mm_pool16c_op && + (ip->mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op)) + return 1; + return 0; + } + + if (ip->j_format.opcode == mm_j32_op) + return 1; + if (ip->j_format.opcode == mm_jal32_op) + return 1; + if (ip->r_format.opcode != mm_pool32a_op || + ip->r_format.func != mm_pool32axf_op) + return 0; + return ((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op; +#else + if (ip->j_format.opcode == j_op) + return 1; + if (ip->j_format.opcode == jal_op) + return 1; + if (ip->r_format.opcode != spec_op) + return 0; + return ip->r_format.func == jalr_op || ip->r_format.func == jr_op; +#endif +} + +static inline int is_sp_move_ins(union mips_instruction *ip, int *frame_size) +{ +#ifdef CONFIG_CPU_MICROMIPS + unsigned short tmp; + + /* + * addiusp -imm + * addius5 sp,-imm + * addiu32 sp,sp,-imm + * jradiussp - NOT SUPPORTED + * + * microMIPS is not more fun... + */ + if (mm_insn_16bit(ip->word >> 16)) { + if (ip->mm16_r3_format.opcode == mm_pool16d_op && + ip->mm16_r3_format.simmediate & mm_addiusp_func) { + tmp = ip->mm_b0_format.simmediate >> 1; + tmp = ((tmp & 0x1ff) ^ 0x100) - 0x100; + if ((tmp + 2) < 4) /* 0x0,0x1,0x1fe,0x1ff are special */ + tmp ^= 0x100; + *frame_size = -(signed short)(tmp << 2); + return 1; + } + if (ip->mm16_r5_format.opcode == mm_pool16d_op && + ip->mm16_r5_format.rt == 29) { + tmp = ip->mm16_r5_format.imm >> 1; + *frame_size = -(signed short)(tmp & 0xf); + return 1; + } + return 0; + } + + if (ip->mm_i_format.opcode == mm_addiu32_op && + ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29) { + *frame_size = -ip->i_format.simmediate; + return 1; + } +#else + /* addiu/daddiu sp,sp,-imm */ + if (ip->i_format.rs != 29 || ip->i_format.rt != 29) + return 0; + + if (ip->i_format.opcode == addiu_op || + ip->i_format.opcode == daddiu_op) { + *frame_size = -ip->i_format.simmediate; + return 1; + } +#endif + return 0; +} + +static int get_frame_info(struct mips_frame_info *info) +{ + bool is_mmips = IS_ENABLED(CONFIG_CPU_MICROMIPS); + union mips_instruction insn, *ip, *ip_end; + unsigned int last_insn_size = 0; + bool saw_jump = false; + + info->pc_offset = -1; + info->frame_size = 0; + + ip = (void *)msk_isa16_mode((ulong)info->func); + if (!ip) + goto err; + + ip_end = (void *)ip + (info->func_size ? info->func_size : 512); + + while (ip < ip_end) { + ip = (void *)ip + last_insn_size; + + if (is_mmips && mm_insn_16bit(ip->halfword[0])) { + insn.word = ip->halfword[0] << 16; + last_insn_size = 2; + } else if (is_mmips) { + insn.word = ip->halfword[0] << 16 | ip->halfword[1]; + last_insn_size = 4; + } else { + insn.word = ip->word; + last_insn_size = 4; + } + + if (is_jr_ra_ins(ip)) { + break; + } else if (!info->frame_size) { + is_sp_move_ins(&insn, &info->frame_size); + continue; + } else if (!saw_jump && is_jump_ins(ip)) { + /* + * If we see a jump instruction, we are finished + * with the frame save. + * + * Some functions can have a shortcut return at + * the beginning of the function, so don't start + * looking for jump instruction until we see the + * frame setup. + * + * The RA save instruction can get put into the + * delay slot of the jump instruction, so look + * at the next instruction, too. + */ + saw_jump = true; + continue; + } + if (info->pc_offset == -1 && + is_ra_save_ins(&insn, &info->pc_offset)) + break; + if (saw_jump) + break; + } + if (info->frame_size && info->pc_offset >= 0) /* nested */ + return 0; + if (info->pc_offset < 0) /* leaf */ + return 1; + /* prologue seems bogus... */ +err: + return -1; +} + +static struct mips_frame_info schedule_mfi __read_mostly; + +#ifdef CONFIG_KALLSYMS +static unsigned long get___schedule_addr(void) +{ + return kallsyms_lookup_name("__schedule"); +} +#else +static unsigned long get___schedule_addr(void) +{ + union mips_instruction *ip = (void *)schedule; + int max_insns = 8; + int i; + + for (i = 0; i < max_insns; i++, ip++) { + if (ip->j_format.opcode == j_op) + return J_TARGET(ip, ip->j_format.target); + } + return 0; +} +#endif + +static int __init frame_info_init(void) +{ + unsigned long size = 0; +#ifdef CONFIG_KALLSYMS + unsigned long ofs; +#endif + unsigned long addr; + + addr = get___schedule_addr(); + if (!addr) + addr = (unsigned long)schedule; + +#ifdef CONFIG_KALLSYMS + kallsyms_lookup_size_offset(addr, &size, &ofs); +#endif + schedule_mfi.func = (void *)addr; + schedule_mfi.func_size = size; + + get_frame_info(&schedule_mfi); + + /* + * Without schedule() frame info, result given by + * thread_saved_pc() and __get_wchan() are not reliable. + */ + if (schedule_mfi.pc_offset < 0) + printk("Can't analyze schedule() prologue at %p\n", schedule); + + return 0; +} + +arch_initcall(frame_info_init); + +/* + * Return saved PC of a blocked thread. + */ +static unsigned long thread_saved_pc(struct task_struct *tsk) +{ + struct thread_struct *t = &tsk->thread; + + /* New born processes are a special case */ + if (t->reg31 == (unsigned long) ret_from_fork) + return t->reg31; + if (schedule_mfi.pc_offset < 0) + return 0; + return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset]; +} + + +#ifdef CONFIG_KALLSYMS +/* generic stack unwinding function */ +unsigned long notrace unwind_stack_by_address(unsigned long stack_page, + unsigned long *sp, + unsigned long pc, + unsigned long *ra) +{ + unsigned long low, high, irq_stack_high; + struct mips_frame_info info; + unsigned long size, ofs; + struct pt_regs *regs; + int leaf; + + if (!stack_page) + return 0; + + /* + * IRQ stacks start at IRQ_STACK_START + * task stacks at THREAD_SIZE - 32 + */ + low = stack_page; + if (!preemptible() && on_irq_stack(raw_smp_processor_id(), *sp)) { + high = stack_page + IRQ_STACK_START; + irq_stack_high = high; + } else { + high = stack_page + THREAD_SIZE - 32; + irq_stack_high = 0; + } + + /* + * If we reached the top of the interrupt stack, start unwinding + * the interrupted task stack. + */ + if (unlikely(*sp == irq_stack_high)) { + unsigned long task_sp = *(unsigned long *)*sp; + + /* + * Check that the pointer saved in the IRQ stack head points to + * something within the stack of the current task + */ + if (!object_is_on_stack((void *)task_sp)) + return 0; + + /* + * Follow pointer to tasks kernel stack frame where interrupted + * state was saved. + */ + regs = (struct pt_regs *)task_sp; + pc = regs->cp0_epc; + if (!user_mode(regs) && __kernel_text_address(pc)) { + *sp = regs->regs[29]; + *ra = regs->regs[31]; + return pc; + } + return 0; + } + if (!kallsyms_lookup_size_offset(pc, &size, &ofs)) + return 0; + /* + * Return ra if an exception occurred at the first instruction + */ + if (unlikely(ofs == 0)) { + pc = *ra; + *ra = 0; + return pc; + } + + info.func = (void *)(pc - ofs); + info.func_size = ofs; /* analyze from start to ofs */ + leaf = get_frame_info(&info); + if (leaf < 0) + return 0; + + if (*sp < low || *sp + info.frame_size > high) + return 0; + + if (leaf) + /* + * For some extreme cases, get_frame_info() can + * consider wrongly a nested function as a leaf + * one. In that cases avoid to return always the + * same value. + */ + pc = pc != *ra ? *ra : 0; + else + pc = ((unsigned long *)(*sp))[info.pc_offset]; + + *sp += info.frame_size; + *ra = 0; + return __kernel_text_address(pc) ? pc : 0; +} +EXPORT_SYMBOL(unwind_stack_by_address); + +/* used by show_backtrace() */ +unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, + unsigned long pc, unsigned long *ra) +{ + unsigned long stack_page = 0; + int cpu; + + for_each_possible_cpu(cpu) { + if (on_irq_stack(cpu, *sp)) { + stack_page = (unsigned long)irq_stack[cpu]; + break; + } + } + + if (!stack_page) + stack_page = (unsigned long)task_stack_page(task); + + return unwind_stack_by_address(stack_page, sp, pc, ra); +} +#endif + +/* + * __get_wchan - a maintenance nightmare^W^Wpain in the ass ... + */ +unsigned long __get_wchan(struct task_struct *task) +{ + unsigned long pc = 0; +#ifdef CONFIG_KALLSYMS + unsigned long sp; + unsigned long ra = 0; +#endif + + if (!task_stack_page(task)) + goto out; + + pc = thread_saved_pc(task); + +#ifdef CONFIG_KALLSYMS + sp = task->thread.reg29 + schedule_mfi.frame_size; + + while (in_sched_functions(pc)) + pc = unwind_stack(task, &sp, pc, &ra); +#endif + +out: + return pc; +} + +unsigned long mips_stack_top(void) +{ + unsigned long top = TASK_SIZE & PAGE_MASK; + + if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) { + /* One page for branch delay slot "emulation" */ + top -= PAGE_SIZE; + } + + /* Space for the VDSO, data page & GIC user page */ + top -= PAGE_ALIGN(current->thread.abi->vdso->size); + top -= PAGE_SIZE; + top -= mips_gic_present() ? PAGE_SIZE : 0; + + /* Space for cache colour alignment */ + if (cpu_has_dc_aliases) + top -= shm_align_mask + 1; + + /* Space to randomize the VDSO base */ + if (current->flags & PF_RANDOMIZE) + top -= VDSO_RANDOMIZE_SIZE; + + return top; +} + +/* + * Don't forget that the stack pointer must be aligned on a 8 bytes + * boundary for 32-bits ABI and 16 bytes for 64-bits ABI. + */ +unsigned long arch_align_stack(unsigned long sp) +{ + if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) + sp -= get_random_u32_below(PAGE_SIZE); + + return sp & ALMASK; +} + +static struct cpumask backtrace_csd_busy; + +static void handle_backtrace(void *info) +{ + nmi_cpu_backtrace(get_irq_regs()); + cpumask_clear_cpu(smp_processor_id(), &backtrace_csd_busy); +} + +static DEFINE_PER_CPU(call_single_data_t, backtrace_csd) = + CSD_INIT(handle_backtrace, NULL); + +static void raise_backtrace(cpumask_t *mask) +{ + call_single_data_t *csd; + int cpu; + + for_each_cpu(cpu, mask) { + /* + * If we previously sent an IPI to the target CPU & it hasn't + * cleared its bit in the busy cpumask then it didn't handle + * our previous IPI & it's not safe for us to reuse the + * call_single_data_t. + */ + if (cpumask_test_and_set_cpu(cpu, &backtrace_csd_busy)) { + pr_warn("Unable to send backtrace IPI to CPU%u - perhaps it hung?\n", + cpu); + continue; + } + + csd = &per_cpu(backtrace_csd, cpu); + smp_call_function_single_async(cpu, csd); + } +} + +void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self) +{ + nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace); +} + +int mips_get_process_fp_mode(struct task_struct *task) +{ + int value = 0; + + if (!test_tsk_thread_flag(task, TIF_32BIT_FPREGS)) + value |= PR_FP_MODE_FR; + if (test_tsk_thread_flag(task, TIF_HYBRID_FPREGS)) + value |= PR_FP_MODE_FRE; + + return value; +} + +static long prepare_for_fp_mode_switch(void *unused) +{ + /* + * This is icky, but we use this to simply ensure that all CPUs have + * context switched, regardless of whether they were previously running + * kernel or user code. This ensures that no CPU that a mode-switching + * program may execute on keeps its FPU enabled (& in the old mode) + * throughout the mode switch. + */ + return 0; +} + +int mips_set_process_fp_mode(struct task_struct *task, unsigned int value) +{ + const unsigned int known_bits = PR_FP_MODE_FR | PR_FP_MODE_FRE; + struct task_struct *t; + struct cpumask process_cpus; + int cpu; + + /* If nothing to change, return right away, successfully. */ + if (value == mips_get_process_fp_mode(task)) + return 0; + + /* Only accept a mode change if 64-bit FP enabled for o32. */ + if (!IS_ENABLED(CONFIG_MIPS_O32_FP64_SUPPORT)) + return -EOPNOTSUPP; + + /* And only for o32 tasks. */ + if (IS_ENABLED(CONFIG_64BIT) && !test_thread_flag(TIF_32BIT_REGS)) + return -EOPNOTSUPP; + + /* Check the value is valid */ + if (value & ~known_bits) + return -EOPNOTSUPP; + + /* Setting FRE without FR is not supported. */ + if ((value & (PR_FP_MODE_FR | PR_FP_MODE_FRE)) == PR_FP_MODE_FRE) + return -EOPNOTSUPP; + + /* Avoid inadvertently triggering emulation */ + if ((value & PR_FP_MODE_FR) && raw_cpu_has_fpu && + !(raw_current_cpu_data.fpu_id & MIPS_FPIR_F64)) + return -EOPNOTSUPP; + if ((value & PR_FP_MODE_FRE) && raw_cpu_has_fpu && !cpu_has_fre) + return -EOPNOTSUPP; + + /* FR = 0 not supported in MIPS R6 */ + if (!(value & PR_FP_MODE_FR) && raw_cpu_has_fpu && cpu_has_mips_r6) + return -EOPNOTSUPP; + + /* Indicate the new FP mode in each thread */ + for_each_thread(task, t) { + /* Update desired FP register width */ + if (value & PR_FP_MODE_FR) { + clear_tsk_thread_flag(t, TIF_32BIT_FPREGS); + } else { + set_tsk_thread_flag(t, TIF_32BIT_FPREGS); + clear_tsk_thread_flag(t, TIF_MSA_CTX_LIVE); + } + + /* Update desired FP single layout */ + if (value & PR_FP_MODE_FRE) + set_tsk_thread_flag(t, TIF_HYBRID_FPREGS); + else + clear_tsk_thread_flag(t, TIF_HYBRID_FPREGS); + } + + /* + * We need to ensure that all threads in the process have switched mode + * before returning, in order to allow userland to not worry about + * races. We can do this by forcing all CPUs that any thread in the + * process may be running on to schedule something else - in this case + * prepare_for_fp_mode_switch(). + * + * We begin by generating a mask of all CPUs that any thread in the + * process may be running on. + */ + cpumask_clear(&process_cpus); + for_each_thread(task, t) + cpumask_set_cpu(task_cpu(t), &process_cpus); + + /* + * Now we schedule prepare_for_fp_mode_switch() on each of those CPUs. + * + * The CPUs may have rescheduled already since we switched mode or + * generated the cpumask, but that doesn't matter. If the task in this + * process is scheduled out then our scheduling + * prepare_for_fp_mode_switch() will simply be redundant. If it's + * scheduled in then it will already have picked up the new FP mode + * whilst doing so. + */ + cpus_read_lock(); + for_each_cpu_and(cpu, &process_cpus, cpu_online_mask) + work_on_cpu(cpu, prepare_for_fp_mode_switch, NULL); + cpus_read_unlock(); + + return 0; +} + +#if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32) +void mips_dump_regs32(u32 *uregs, const struct pt_regs *regs) +{ + unsigned int i; + + for (i = MIPS32_EF_R1; i <= MIPS32_EF_R31; i++) { + /* k0/k1 are copied as zero. */ + if (i == MIPS32_EF_R26 || i == MIPS32_EF_R27) + uregs[i] = 0; + else + uregs[i] = regs->regs[i - MIPS32_EF_R0]; + } + + uregs[MIPS32_EF_LO] = regs->lo; + uregs[MIPS32_EF_HI] = regs->hi; + uregs[MIPS32_EF_CP0_EPC] = regs->cp0_epc; + uregs[MIPS32_EF_CP0_BADVADDR] = regs->cp0_badvaddr; + uregs[MIPS32_EF_CP0_STATUS] = regs->cp0_status; + uregs[MIPS32_EF_CP0_CAUSE] = regs->cp0_cause; +} +#endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */ + +#ifdef CONFIG_64BIT +void mips_dump_regs64(u64 *uregs, const struct pt_regs *regs) +{ + unsigned int i; + + for (i = MIPS64_EF_R1; i <= MIPS64_EF_R31; i++) { + /* k0/k1 are copied as zero. */ + if (i == MIPS64_EF_R26 || i == MIPS64_EF_R27) + uregs[i] = 0; + else + uregs[i] = regs->regs[i - MIPS64_EF_R0]; + } + + uregs[MIPS64_EF_LO] = regs->lo; + uregs[MIPS64_EF_HI] = regs->hi; + uregs[MIPS64_EF_CP0_EPC] = regs->cp0_epc; + uregs[MIPS64_EF_CP0_BADVADDR] = regs->cp0_badvaddr; + uregs[MIPS64_EF_CP0_STATUS] = regs->cp0_status; + uregs[MIPS64_EF_CP0_CAUSE] = regs->cp0_cause; +} +#endif /* CONFIG_64BIT */ |