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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 | // SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2012 Regents of the University of California */ #include <linux/kernel.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/sched/debug.h> #include <linux/sched/signal.h> #include <linux/signal.h> #include <linux/kdebug.h> #include <linux/uaccess.h> #include <linux/mm.h> #include <linux/module.h> #include <linux/irq.h> #include <asm/processor.h> #include <asm/ptrace.h> #include <asm/csr.h> int show_unhandled_signals = 1; extern asmlinkage void handle_exception(void); static DEFINE_SPINLOCK(die_lock); void die(struct pt_regs *regs, const char *str) { static int die_counter; int ret; oops_enter(); spin_lock_irq(&die_lock); console_verbose(); bust_spinlocks(1); pr_emerg("%s [#%d]\n", str, ++die_counter); print_modules(); show_regs(regs); ret = notify_die(DIE_OOPS, str, regs, 0, regs->scause, SIGSEGV); bust_spinlocks(0); add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); spin_unlock_irq(&die_lock); oops_exit(); if (in_interrupt()) panic("Fatal exception in interrupt"); if (panic_on_oops) panic("Fatal exception"); if (ret != NOTIFY_STOP) do_exit(SIGSEGV); } void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr) { struct task_struct *tsk = current; if (show_unhandled_signals && unhandled_signal(tsk, signo) && printk_ratelimit()) { pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT, tsk->comm, task_pid_nr(tsk), signo, code, addr); print_vma_addr(KERN_CONT " in ", instruction_pointer(regs)); pr_cont("\n"); show_regs(regs); } force_sig_fault(signo, code, (void __user *)addr); } static void do_trap_error(struct pt_regs *regs, int signo, int code, unsigned long addr, const char *str) { if (user_mode(regs)) { do_trap(regs, signo, code, addr); } else { if (!fixup_exception(regs)) die(regs, str); } } #define DO_ERROR_INFO(name, signo, code, str) \ asmlinkage void name(struct pt_regs *regs) \ { \ do_trap_error(regs, signo, code, regs->sepc, "Oops - " str); \ } DO_ERROR_INFO(do_trap_unknown, SIGILL, ILL_ILLTRP, "unknown exception"); DO_ERROR_INFO(do_trap_insn_misaligned, SIGBUS, BUS_ADRALN, "instruction address misaligned"); DO_ERROR_INFO(do_trap_insn_fault, SIGSEGV, SEGV_ACCERR, "instruction access fault"); DO_ERROR_INFO(do_trap_insn_illegal, SIGILL, ILL_ILLOPC, "illegal instruction"); DO_ERROR_INFO(do_trap_load_misaligned, SIGBUS, BUS_ADRALN, "load address misaligned"); DO_ERROR_INFO(do_trap_load_fault, SIGSEGV, SEGV_ACCERR, "load access fault"); DO_ERROR_INFO(do_trap_store_misaligned, SIGBUS, BUS_ADRALN, "store (or AMO) address misaligned"); DO_ERROR_INFO(do_trap_store_fault, SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault"); DO_ERROR_INFO(do_trap_ecall_u, SIGILL, ILL_ILLTRP, "environment call from U-mode"); DO_ERROR_INFO(do_trap_ecall_s, SIGILL, ILL_ILLTRP, "environment call from S-mode"); DO_ERROR_INFO(do_trap_ecall_m, SIGILL, ILL_ILLTRP, "environment call from M-mode"); #ifdef CONFIG_GENERIC_BUG static inline unsigned long get_break_insn_length(unsigned long pc) { bug_insn_t insn; if (probe_kernel_address((bug_insn_t *)pc, insn)) return 0; return (((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32) ? 4UL : 2UL); } #endif /* CONFIG_GENERIC_BUG */ asmlinkage void do_trap_break(struct pt_regs *regs) { if (!user_mode(regs)) { enum bug_trap_type type; type = report_bug(regs->sepc, regs); switch (type) { #ifdef CONFIG_GENERIC_BUG case BUG_TRAP_TYPE_WARN: regs->sepc += get_break_insn_length(regs->sepc); return; case BUG_TRAP_TYPE_BUG: #endif /* CONFIG_GENERIC_BUG */ default: die(regs, "Kernel BUG"); } } else { force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)(regs->sepc)); } } #ifdef CONFIG_GENERIC_BUG int is_valid_bugaddr(unsigned long pc) { bug_insn_t insn; if (pc < VMALLOC_START) return 0; if (probe_kernel_address((bug_insn_t *)pc, insn)) return 0; if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32) return (insn == __BUG_INSN_32); else return ((insn & __COMPRESSED_INSN_MASK) == __BUG_INSN_16); } #endif /* CONFIG_GENERIC_BUG */ void __init trap_init(void) { /* * Set sup0 scratch register to 0, indicating to exception vector * that we are presently executing in the kernel */ csr_write(CSR_SSCRATCH, 0); /* Set the exception vector address */ csr_write(CSR_STVEC, &handle_exception); /* Enable all interrupts */ csr_write(CSR_SIE, -1); } |