2 * Copyright (C) 2012 Regents of the University of California
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/sched.h>
17 #include <linux/sched/debug.h>
18 #include <linux/sched/signal.h>
19 #include <linux/signal.h>
20 #include <linux/kdebug.h>
21 #include <linux/uaccess.h>
23 #include <linux/module.h>
24 #include <linux/irq.h>
25 #include <linux/kexec.h>
27 #include <asm/processor.h>
28 #include <asm/ptrace.h>
31 int show_unhandled_signals = 1;
33 extern asmlinkage void handle_exception(void);
35 static DEFINE_SPINLOCK(die_lock);
37 void die(struct pt_regs *regs, const char *str)
39 static int die_counter;
44 spin_lock_irq(&die_lock);
48 pr_emerg("%s [#%d]\n", str, ++die_counter);
52 ret = notify_die(DIE_OOPS, str, regs, 0, regs->scause, SIGSEGV);
54 if (regs && kexec_should_crash(current))
58 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
59 spin_unlock_irq(&die_lock);
63 panic("Fatal exception in interrupt");
65 panic("Fatal exception");
66 if (ret != NOTIFY_STOP)
67 make_task_dead(SIGSEGV);
70 void do_trap(struct pt_regs *regs, int signo, int code,
71 unsigned long addr, struct task_struct *tsk)
73 if (show_unhandled_signals && unhandled_signal(tsk, signo)
74 && printk_ratelimit()) {
75 pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT,
76 tsk->comm, task_pid_nr(tsk), signo, code, addr);
77 print_vma_addr(KERN_CONT " in ", GET_IP(regs));
82 force_sig_fault(signo, code, (void __user *)addr, tsk);
85 static void do_trap_error(struct pt_regs *regs, int signo, int code,
86 unsigned long addr, const char *str)
88 if (user_mode(regs)) {
89 do_trap(regs, signo, code, addr, current);
91 if (!fixup_exception(regs))
96 #define DO_ERROR_INFO(name, signo, code, str) \
97 asmlinkage void name(struct pt_regs *regs) \
99 do_trap_error(regs, signo, code, regs->sepc, "Oops - " str); \
102 DO_ERROR_INFO(do_trap_unknown,
103 SIGILL, ILL_ILLTRP, "unknown exception");
104 DO_ERROR_INFO(do_trap_insn_misaligned,
105 SIGBUS, BUS_ADRALN, "instruction address misaligned");
106 DO_ERROR_INFO(do_trap_insn_fault,
107 SIGSEGV, SEGV_ACCERR, "instruction access fault");
108 DO_ERROR_INFO(do_trap_insn_illegal,
109 SIGILL, ILL_ILLOPC, "illegal instruction");
110 DO_ERROR_INFO(do_trap_load_misaligned,
111 SIGBUS, BUS_ADRALN, "load address misaligned");
112 DO_ERROR_INFO(do_trap_load_fault,
113 SIGSEGV, SEGV_ACCERR, "load access fault");
114 DO_ERROR_INFO(do_trap_store_misaligned,
115 SIGBUS, BUS_ADRALN, "store (or AMO) address misaligned");
116 DO_ERROR_INFO(do_trap_store_fault,
117 SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault");
118 DO_ERROR_INFO(do_trap_ecall_u,
119 SIGILL, ILL_ILLTRP, "environment call from U-mode");
120 DO_ERROR_INFO(do_trap_ecall_s,
121 SIGILL, ILL_ILLTRP, "environment call from S-mode");
122 DO_ERROR_INFO(do_trap_ecall_m,
123 SIGILL, ILL_ILLTRP, "environment call from M-mode");
125 asmlinkage void do_trap_break(struct pt_regs *regs)
127 #ifdef CONFIG_GENERIC_BUG
128 if (!user_mode(regs)) {
129 enum bug_trap_type type;
131 type = report_bug(regs->sepc, regs);
133 case BUG_TRAP_TYPE_NONE:
135 case BUG_TRAP_TYPE_WARN:
136 regs->sepc += sizeof(bug_insn_t);
138 case BUG_TRAP_TYPE_BUG:
139 die(regs, "Kernel BUG");
142 #endif /* CONFIG_GENERIC_BUG */
144 force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)(regs->sepc), current);
147 #ifdef CONFIG_GENERIC_BUG
148 int is_valid_bugaddr(unsigned long pc)
152 if (pc < PAGE_OFFSET)
154 if (probe_kernel_address((bug_insn_t *)pc, insn))
156 return (insn == __BUG_INSN);
158 #endif /* CONFIG_GENERIC_BUG */
160 void __init trap_init(void)
163 * Set sup0 scratch register to 0, indicating to exception vector
164 * that we are presently executing in the kernel
166 csr_write(sscratch, 0);
167 /* Set the exception vector address */
168 csr_write(stvec, &handle_exception);
169 /* Enable all interrupts */