188 lines
5.0 KiB
C
188 lines
5.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
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* Chen Liqin <liqin.chen@sunplusct.com>
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* Lennox Wu <lennox.wu@sunplusct.com>
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* Copyright (C) 2012 Regents of the University of California
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* Copyright (C) 2017 SiFive
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*/
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#include <linux/cpu.h>
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#include <linux/kernel.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_stack.h>
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#include <linux/tick.h>
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#include <linux/ptrace.h>
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#include <linux/uaccess.h>
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#include <asm/unistd.h>
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#include <asm/processor.h>
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#include <asm/csr.h>
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#include <asm/stacktrace.h>
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#include <asm/string.h>
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#include <asm/switch_to.h>
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#include <asm/thread_info.h>
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#include <asm/cpuidle.h>
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register unsigned long gp_in_global __asm__("gp");
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#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK)
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#include <linux/stackprotector.h>
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unsigned long __stack_chk_guard __read_mostly;
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EXPORT_SYMBOL(__stack_chk_guard);
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#endif
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extern asmlinkage void ret_from_fork(void);
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extern asmlinkage void ret_from_kernel_thread(void);
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void arch_cpu_idle(void)
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{
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cpu_do_idle();
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raw_local_irq_enable();
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}
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void __show_regs(struct pt_regs *regs)
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{
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show_regs_print_info(KERN_DEFAULT);
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if (!user_mode(regs)) {
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pr_cont("epc : %pS\n", (void *)regs->epc);
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pr_cont(" ra : %pS\n", (void *)regs->ra);
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}
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pr_cont("epc : " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n",
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regs->epc, regs->ra, regs->sp);
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pr_cont(" gp : " REG_FMT " tp : " REG_FMT " t0 : " REG_FMT "\n",
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regs->gp, regs->tp, regs->t0);
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pr_cont(" t1 : " REG_FMT " t2 : " REG_FMT " s0 : " REG_FMT "\n",
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regs->t1, regs->t2, regs->s0);
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pr_cont(" s1 : " REG_FMT " a0 : " REG_FMT " a1 : " REG_FMT "\n",
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regs->s1, regs->a0, regs->a1);
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pr_cont(" a2 : " REG_FMT " a3 : " REG_FMT " a4 : " REG_FMT "\n",
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regs->a2, regs->a3, regs->a4);
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pr_cont(" a5 : " REG_FMT " a6 : " REG_FMT " a7 : " REG_FMT "\n",
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regs->a5, regs->a6, regs->a7);
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pr_cont(" s2 : " REG_FMT " s3 : " REG_FMT " s4 : " REG_FMT "\n",
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regs->s2, regs->s3, regs->s4);
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pr_cont(" s5 : " REG_FMT " s6 : " REG_FMT " s7 : " REG_FMT "\n",
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regs->s5, regs->s6, regs->s7);
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pr_cont(" s8 : " REG_FMT " s9 : " REG_FMT " s10: " REG_FMT "\n",
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regs->s8, regs->s9, regs->s10);
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pr_cont(" s11: " REG_FMT " t3 : " REG_FMT " t4 : " REG_FMT "\n",
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regs->s11, regs->t3, regs->t4);
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pr_cont(" t5 : " REG_FMT " t6 : " REG_FMT "\n",
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regs->t5, regs->t6);
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pr_cont("status: " REG_FMT " badaddr: " REG_FMT " cause: " REG_FMT "\n",
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regs->status, regs->badaddr, regs->cause);
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}
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void show_regs(struct pt_regs *regs)
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{
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__show_regs(regs);
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if (!user_mode(regs))
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dump_backtrace(regs, NULL, KERN_DEFAULT);
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}
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#ifdef CONFIG_COMPAT
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static bool compat_mode_supported __read_mostly;
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bool compat_elf_check_arch(Elf32_Ehdr *hdr)
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{
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return compat_mode_supported &&
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hdr->e_machine == EM_RISCV &&
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hdr->e_ident[EI_CLASS] == ELFCLASS32;
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}
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static int __init compat_mode_detect(void)
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{
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unsigned long tmp = csr_read(CSR_STATUS);
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csr_write(CSR_STATUS, (tmp & ~SR_UXL) | SR_UXL_32);
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compat_mode_supported =
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(csr_read(CSR_STATUS) & SR_UXL) == SR_UXL_32;
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csr_write(CSR_STATUS, tmp);
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pr_info("riscv: ELF compat mode %s",
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compat_mode_supported ? "supported" : "failed");
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return 0;
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}
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early_initcall(compat_mode_detect);
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#endif
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void start_thread(struct pt_regs *regs, unsigned long pc,
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unsigned long sp)
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{
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regs->status = SR_PIE;
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if (has_fpu()) {
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regs->status |= SR_FS_INITIAL;
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/*
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* Restore the initial value to the FP register
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* before starting the user program.
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*/
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fstate_restore(current, regs);
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}
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regs->epc = pc;
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regs->sp = sp;
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#ifdef CONFIG_64BIT
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regs->status &= ~SR_UXL;
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if (is_compat_task())
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regs->status |= SR_UXL_32;
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else
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regs->status |= SR_UXL_64;
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#endif
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}
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void flush_thread(void)
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{
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#ifdef CONFIG_FPU
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/*
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* Reset FPU state and context
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* frm: round to nearest, ties to even (IEEE default)
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* fflags: accrued exceptions cleared
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*/
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fstate_off(current, task_pt_regs(current));
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memset(¤t->thread.fstate, 0, sizeof(current->thread.fstate));
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#endif
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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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fstate_save(src, task_pt_regs(src));
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*dst = *src;
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return 0;
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}
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int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
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struct task_struct *p, unsigned long tls)
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{
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struct pt_regs *childregs = task_pt_regs(p);
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/* p->thread holds context to be restored by __switch_to() */
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if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
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/* Kernel thread */
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memset(childregs, 0, sizeof(struct pt_regs));
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childregs->gp = gp_in_global;
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/* Supervisor/Machine, irqs on: */
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childregs->status = SR_PP | SR_PIE;
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p->thread.ra = (unsigned long)ret_from_kernel_thread;
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p->thread.s[0] = usp; /* fn */
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p->thread.s[1] = arg;
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} else {
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*childregs = *(current_pt_regs());
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if (usp) /* User fork */
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childregs->sp = usp;
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if (clone_flags & CLONE_SETTLS)
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childregs->tp = tls;
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childregs->a0 = 0; /* Return value of fork() */
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p->thread.ra = (unsigned long)ret_from_fork;
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}
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p->thread.sp = (unsigned long)childregs; /* kernel sp */
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return 0;
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}
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