1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2012 Regents of the University of California
7 #include <linux/kernel.h>
8 #include <linux/init.h>
9 #include <linux/sched.h>
10 #include <linux/sched/debug.h>
11 #include <linux/sched/signal.h>
12 #include <linux/signal.h>
13 #include <linux/kdebug.h>
14 #include <linux/uaccess.h>
15 #include <linux/kprobes.h>
17 #include <linux/module.h>
18 #include <linux/irq.h>
20 #include <asm/asm-prototypes.h>
22 #include <asm/processor.h>
23 #include <asm/ptrace.h>
26 int show_unhandled_signals = 1;
28 static DEFINE_SPINLOCK(die_lock);
30 void die(struct pt_regs *regs, const char *str)
32 static int die_counter;
37 spin_lock_irq(&die_lock);
41 pr_emerg("%s [#%d]\n", str, ++die_counter);
45 ret = notify_die(DIE_OOPS, str, regs, 0, regs->cause, SIGSEGV);
48 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
49 spin_unlock_irq(&die_lock);
53 panic("Fatal exception in interrupt");
55 panic("Fatal exception");
56 if (ret != NOTIFY_STOP)
60 void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr)
62 struct task_struct *tsk = current;
64 if (show_unhandled_signals && unhandled_signal(tsk, signo)
65 && printk_ratelimit()) {
66 pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT,
67 tsk->comm, task_pid_nr(tsk), signo, code, addr);
68 print_vma_addr(KERN_CONT " in ", instruction_pointer(regs));
73 force_sig_fault(signo, code, (void __user *)addr);
76 static void do_trap_error(struct pt_regs *regs, int signo, int code,
77 unsigned long addr, const char *str)
79 current->thread.bad_cause = regs->cause;
81 if (user_mode(regs)) {
82 do_trap(regs, signo, code, addr);
84 if (!fixup_exception(regs))
89 #if defined (CONFIG_XIP_KERNEL) && defined (CONFIG_RISCV_ERRATA_ALTERNATIVE)
90 #define __trap_section __section(".xip.traps")
92 #define __trap_section
94 #define DO_ERROR_INFO(name, signo, code, str) \
95 asmlinkage __visible __trap_section void name(struct pt_regs *regs) \
97 do_trap_error(regs, signo, code, regs->epc, "Oops - " str); \
100 DO_ERROR_INFO(do_trap_unknown,
101 SIGILL, ILL_ILLTRP, "unknown exception");
102 DO_ERROR_INFO(do_trap_insn_misaligned,
103 SIGBUS, BUS_ADRALN, "instruction address misaligned");
104 DO_ERROR_INFO(do_trap_insn_fault,
105 SIGSEGV, SEGV_ACCERR, "instruction access fault");
106 DO_ERROR_INFO(do_trap_insn_illegal,
107 SIGILL, ILL_ILLOPC, "illegal instruction");
108 DO_ERROR_INFO(do_trap_load_fault,
109 SIGSEGV, SEGV_ACCERR, "load access fault");
110 #ifndef CONFIG_RISCV_M_MODE
111 DO_ERROR_INFO(do_trap_load_misaligned,
112 SIGBUS, BUS_ADRALN, "Oops - load address misaligned");
113 DO_ERROR_INFO(do_trap_store_misaligned,
114 SIGBUS, BUS_ADRALN, "Oops - store (or AMO) address misaligned");
116 int handle_misaligned_load(struct pt_regs *regs);
117 int handle_misaligned_store(struct pt_regs *regs);
119 asmlinkage void __trap_section do_trap_load_misaligned(struct pt_regs *regs)
121 if (!handle_misaligned_load(regs))
123 do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
124 "Oops - load address misaligned");
127 asmlinkage void __trap_section do_trap_store_misaligned(struct pt_regs *regs)
129 if (!handle_misaligned_store(regs))
131 do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
132 "Oops - store (or AMO) address misaligned");
135 DO_ERROR_INFO(do_trap_store_fault,
136 SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault");
137 DO_ERROR_INFO(do_trap_ecall_u,
138 SIGILL, ILL_ILLTRP, "environment call from U-mode");
139 DO_ERROR_INFO(do_trap_ecall_s,
140 SIGILL, ILL_ILLTRP, "environment call from S-mode");
141 DO_ERROR_INFO(do_trap_ecall_m,
142 SIGILL, ILL_ILLTRP, "environment call from M-mode");
144 static inline unsigned long get_break_insn_length(unsigned long pc)
148 if (get_kernel_nofault(insn, (bug_insn_t *)pc))
151 return GET_INSN_LENGTH(insn);
154 asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs)
156 #ifdef CONFIG_KPROBES
157 if (kprobe_single_step_handler(regs))
160 if (kprobe_breakpoint_handler(regs))
163 #ifdef CONFIG_UPROBES
164 if (uprobe_single_step_handler(regs))
167 if (uprobe_breakpoint_handler(regs))
170 current->thread.bad_cause = regs->cause;
173 force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->epc);
175 else if (notify_die(DIE_TRAP, "EBREAK", regs, 0, regs->cause, SIGTRAP)
179 else if (report_bug(regs->epc, regs) == BUG_TRAP_TYPE_WARN)
180 regs->epc += get_break_insn_length(regs->epc);
182 die(regs, "Kernel BUG");
184 NOKPROBE_SYMBOL(do_trap_break);
186 #ifdef CONFIG_GENERIC_BUG
187 int is_valid_bugaddr(unsigned long pc)
191 if (pc < VMALLOC_START)
193 if (get_kernel_nofault(insn, (bug_insn_t *)pc))
195 if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32)
196 return (insn == __BUG_INSN_32);
198 return ((insn & __COMPRESSED_INSN_MASK) == __BUG_INSN_16);
200 #endif /* CONFIG_GENERIC_BUG */
202 /* stvec & scratch is already set from head.S */
203 void __init trap_init(void)