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358 lines
8.7 KiB
358 lines
8.7 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Author: Huacai Chen <[email protected]> |
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* Copyright (C) 2020-2022 Loongson Technology Corporation Limited |
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* |
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* Derived from MIPS: |
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* Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others. |
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* Copyright (C) 2005, 2006 by Ralf Baechle ([email protected]) |
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* Copyright (C) 1999, 2000 Silicon Graphics, Inc. |
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* Copyright (C) 2004 Thiemo Seufer |
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* Copyright (C) 2013 Imagination Technologies Ltd. |
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*/ |
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#include <linux/cpu.h> |
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#include <linux/init.h> |
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#include <linux/kernel.h> |
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#include <linux/errno.h> |
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#include <linux/sched.h> |
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#include <linux/sched/debug.h> |
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#include <linux/sched/task.h> |
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#include <linux/sched/task_stack.h> |
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#include <linux/mm.h> |
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#include <linux/stddef.h> |
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#include <linux/unistd.h> |
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#include <linux/export.h> |
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#include <linux/ptrace.h> |
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#include <linux/mman.h> |
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#include <linux/personality.h> |
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#include <linux/sys.h> |
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#include <linux/completion.h> |
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#include <linux/kallsyms.h> |
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#include <linux/random.h> |
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#include <linux/prctl.h> |
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#include <linux/nmi.h> |
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#include <asm/asm.h> |
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#include <asm/bootinfo.h> |
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#include <asm/cpu.h> |
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#include <asm/elf.h> |
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#include <asm/fpu.h> |
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#include <asm/io.h> |
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#include <asm/irq.h> |
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#include <asm/irq_regs.h> |
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#include <asm/loongarch.h> |
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#include <asm/pgtable.h> |
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#include <asm/processor.h> |
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#include <asm/reg.h> |
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#include <asm/unwind.h> |
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#include <asm/vdso.h> |
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/* |
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* Idle related variables and functions |
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*/ |
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unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE; |
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EXPORT_SYMBOL(boot_option_idle_override); |
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#ifdef CONFIG_HOTPLUG_CPU |
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void arch_cpu_idle_dead(void) |
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{ |
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play_dead(); |
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} |
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#endif |
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asmlinkage void ret_from_fork(void); |
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asmlinkage void ret_from_kernel_thread(void); |
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void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) |
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{ |
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unsigned long crmd; |
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unsigned long prmd; |
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unsigned long euen; |
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/* New thread loses kernel privileges. */ |
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crmd = regs->csr_crmd & ~(PLV_MASK); |
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crmd |= PLV_USER; |
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regs->csr_crmd = crmd; |
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prmd = regs->csr_prmd & ~(PLV_MASK); |
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prmd |= PLV_USER; |
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regs->csr_prmd = prmd; |
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euen = regs->csr_euen & ~(CSR_EUEN_FPEN); |
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regs->csr_euen = euen; |
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lose_fpu(0); |
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clear_thread_flag(TIF_LSX_CTX_LIVE); |
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clear_thread_flag(TIF_LASX_CTX_LIVE); |
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clear_used_math(); |
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regs->csr_era = pc; |
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regs->regs[3] = sp; |
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} |
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void exit_thread(struct task_struct *tsk) |
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{ |
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} |
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int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) |
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{ |
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/* |
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* Save any process state which is live in hardware registers to the |
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* parent context prior to duplication. This prevents the new child |
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* state becoming stale if the parent is preempted before copy_thread() |
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* gets a chance to save the parent's live hardware registers to the |
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* child context. |
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*/ |
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preempt_disable(); |
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if (is_fpu_owner()) |
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save_fp(current); |
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preempt_enable(); |
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if (used_math()) |
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memcpy(dst, src, sizeof(struct task_struct)); |
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else |
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memcpy(dst, src, offsetof(struct task_struct, thread.fpu.fpr)); |
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return 0; |
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} |
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/* |
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* Copy architecture-specific thread state |
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*/ |
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int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) |
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{ |
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unsigned long childksp; |
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unsigned long tls = args->tls; |
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unsigned long usp = args->stack; |
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unsigned long clone_flags = args->flags; |
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struct pt_regs *childregs, *regs = current_pt_regs(); |
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childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE; |
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/* set up new TSS. */ |
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childregs = (struct pt_regs *) childksp - 1; |
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/* Put the stack after the struct pt_regs. */ |
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childksp = (unsigned long) childregs; |
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p->thread.sched_cfa = 0; |
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p->thread.csr_euen = 0; |
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p->thread.csr_crmd = csr_read32(LOONGARCH_CSR_CRMD); |
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p->thread.csr_prmd = csr_read32(LOONGARCH_CSR_PRMD); |
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p->thread.csr_ecfg = csr_read32(LOONGARCH_CSR_ECFG); |
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if (unlikely(args->fn)) { |
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/* kernel thread */ |
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p->thread.reg03 = childksp; |
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p->thread.reg23 = (unsigned long)args->fn; |
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p->thread.reg24 = (unsigned long)args->fn_arg; |
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p->thread.reg01 = (unsigned long)ret_from_kernel_thread; |
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p->thread.sched_ra = (unsigned long)ret_from_kernel_thread; |
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memset(childregs, 0, sizeof(struct pt_regs)); |
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childregs->csr_euen = p->thread.csr_euen; |
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childregs->csr_crmd = p->thread.csr_crmd; |
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childregs->csr_prmd = p->thread.csr_prmd; |
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childregs->csr_ecfg = p->thread.csr_ecfg; |
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goto out; |
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} |
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/* user thread */ |
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*childregs = *regs; |
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childregs->regs[4] = 0; /* Child gets zero as return value */ |
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if (usp) |
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childregs->regs[3] = usp; |
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p->thread.reg03 = (unsigned long) childregs; |
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p->thread.reg01 = (unsigned long) ret_from_fork; |
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p->thread.sched_ra = (unsigned long) ret_from_fork; |
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/* |
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* New tasks lose permission to use the fpu. This accelerates context |
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* switching for most programs since they don't use the fpu. |
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*/ |
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childregs->csr_euen = 0; |
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if (clone_flags & CLONE_SETTLS) |
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childregs->regs[2] = tls; |
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out: |
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clear_tsk_thread_flag(p, TIF_USEDFPU); |
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clear_tsk_thread_flag(p, TIF_USEDSIMD); |
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clear_tsk_thread_flag(p, TIF_LSX_CTX_LIVE); |
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clear_tsk_thread_flag(p, TIF_LASX_CTX_LIVE); |
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return 0; |
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} |
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unsigned long __get_wchan(struct task_struct *task) |
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{ |
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unsigned long pc; |
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struct unwind_state state; |
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if (!try_get_task_stack(task)) |
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return 0; |
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unwind_start(&state, task, NULL); |
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state.sp = thread_saved_fp(task); |
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get_stack_info(state.sp, state.task, &state.stack_info); |
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state.pc = thread_saved_ra(task); |
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#ifdef CONFIG_UNWINDER_PROLOGUE |
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state.type = UNWINDER_PROLOGUE; |
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#endif |
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for (; !unwind_done(&state); unwind_next_frame(&state)) { |
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pc = unwind_get_return_address(&state); |
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if (!pc) |
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break; |
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if (in_sched_functions(pc)) |
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continue; |
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break; |
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} |
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put_task_stack(task); |
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return pc; |
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} |
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bool in_irq_stack(unsigned long stack, struct stack_info *info) |
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{ |
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unsigned long nextsp; |
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unsigned long begin = (unsigned long)this_cpu_read(irq_stack); |
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unsigned long end = begin + IRQ_STACK_START; |
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if (stack < begin || stack >= end) |
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return false; |
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nextsp = *(unsigned long *)end; |
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if (nextsp & (SZREG - 1)) |
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return false; |
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info->begin = begin; |
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info->end = end; |
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info->next_sp = nextsp; |
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info->type = STACK_TYPE_IRQ; |
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return true; |
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} |
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bool in_task_stack(unsigned long stack, struct task_struct *task, |
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struct stack_info *info) |
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{ |
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unsigned long begin = (unsigned long)task_stack_page(task); |
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unsigned long end = begin + THREAD_SIZE; |
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if (stack < begin || stack >= end) |
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return false; |
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info->begin = begin; |
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info->end = end; |
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info->next_sp = 0; |
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info->type = STACK_TYPE_TASK; |
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return true; |
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} |
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int get_stack_info(unsigned long stack, struct task_struct *task, |
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struct stack_info *info) |
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{ |
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task = task ? : current; |
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if (!stack || stack & (SZREG - 1)) |
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goto unknown; |
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if (in_task_stack(stack, task, info)) |
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return 0; |
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if (task != current) |
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goto unknown; |
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if (in_irq_stack(stack, info)) |
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return 0; |
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unknown: |
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info->type = STACK_TYPE_UNKNOWN; |
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return -EINVAL; |
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} |
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unsigned long stack_top(void) |
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{ |
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unsigned long top = TASK_SIZE & PAGE_MASK; |
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/* Space for the VDSO & data page */ |
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top -= PAGE_ALIGN(current->thread.vdso->size); |
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top -= PAGE_SIZE; |
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/* Space to randomize the VDSO base */ |
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if (current->flags & PF_RANDOMIZE) |
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top -= VDSO_RANDOMIZE_SIZE; |
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return top; |
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} |
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/* |
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* Don't forget that the stack pointer must be aligned on a 8 bytes |
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* boundary for 32-bits ABI and 16 bytes for 64-bits ABI. |
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*/ |
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unsigned long arch_align_stack(unsigned long sp) |
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{ |
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if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) |
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sp -= prandom_u32_max(PAGE_SIZE); |
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return sp & STACK_ALIGN; |
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} |
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static DEFINE_PER_CPU(call_single_data_t, backtrace_csd); |
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static struct cpumask backtrace_csd_busy; |
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static void handle_backtrace(void *info) |
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{ |
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nmi_cpu_backtrace(get_irq_regs()); |
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cpumask_clear_cpu(smp_processor_id(), &backtrace_csd_busy); |
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} |
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static void raise_backtrace(cpumask_t *mask) |
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{ |
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call_single_data_t *csd; |
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int cpu; |
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for_each_cpu(cpu, mask) { |
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/* |
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* If we previously sent an IPI to the target CPU & it hasn't |
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* cleared its bit in the busy cpumask then it didn't handle |
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* our previous IPI & it's not safe for us to reuse the |
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* call_single_data_t. |
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*/ |
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if (cpumask_test_and_set_cpu(cpu, &backtrace_csd_busy)) { |
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pr_warn("Unable to send backtrace IPI to CPU%u - perhaps it hung?\n", |
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cpu); |
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continue; |
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} |
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csd = &per_cpu(backtrace_csd, cpu); |
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csd->func = handle_backtrace; |
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smp_call_function_single_async(cpu, csd); |
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} |
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} |
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void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self) |
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{ |
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nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace); |
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} |
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#ifdef CONFIG_64BIT |
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void loongarch_dump_regs64(u64 *uregs, const struct pt_regs *regs) |
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{ |
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unsigned int i; |
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for (i = LOONGARCH_EF_R1; i <= LOONGARCH_EF_R31; i++) { |
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uregs[i] = regs->regs[i - LOONGARCH_EF_R0]; |
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} |
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uregs[LOONGARCH_EF_ORIG_A0] = regs->orig_a0; |
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uregs[LOONGARCH_EF_CSR_ERA] = regs->csr_era; |
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uregs[LOONGARCH_EF_CSR_BADV] = regs->csr_badvaddr; |
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uregs[LOONGARCH_EF_CSR_CRMD] = regs->csr_crmd; |
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uregs[LOONGARCH_EF_CSR_PRMD] = regs->csr_prmd; |
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uregs[LOONGARCH_EF_CSR_EUEN] = regs->csr_euen; |
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uregs[LOONGARCH_EF_CSR_ECFG] = regs->csr_ecfg; |
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uregs[LOONGARCH_EF_CSR_ESTAT] = regs->csr_estat; |
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} |
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#endif /* CONFIG_64BIT */
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