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6#include <linux/cpu.h>
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>
16#include <linux/mm.h>
17#include <linux/module.h>
18#include <linux/irq.h>
19
20#include <asm/asm-prototypes.h>
21#include <asm/bug.h>
22#include <asm/processor.h>
23#include <asm/ptrace.h>
24#include <asm/csr.h>
25
26int show_unhandled_signals = 1;
27
28static DEFINE_SPINLOCK(die_lock);
29
30void die(struct pt_regs *regs, const char *str)
31{
32 static int die_counter;
33 int ret;
34
35 oops_enter();
36
37 spin_lock_irq(&die_lock);
38 console_verbose();
39 bust_spinlocks(1);
40
41 pr_emerg("%s [#%d]\n", str, ++die_counter);
42 print_modules();
43 show_regs(regs);
44
45 ret = notify_die(DIE_OOPS, str, regs, 0, regs->cause, SIGSEGV);
46
47 bust_spinlocks(0);
48 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
49 spin_unlock_irq(&die_lock);
50 oops_exit();
51
52 if (in_interrupt())
53 panic("Fatal exception in interrupt");
54 if (panic_on_oops)
55 panic("Fatal exception");
56 if (ret != NOTIFY_STOP)
57 do_exit(SIGSEGV);
58}
59
60void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr)
61{
62 struct task_struct *tsk = current;
63
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));
69 pr_cont("\n");
70 __show_regs(regs);
71 }
72
73 force_sig_fault(signo, code, (void __user *)addr);
74}
75
76static void do_trap_error(struct pt_regs *regs, int signo, int code,
77 unsigned long addr, const char *str)
78{
79 current->thread.bad_cause = regs->cause;
80
81 if (user_mode(regs)) {
82 do_trap(regs, signo, code, addr);
83 } else {
84 if (!fixup_exception(regs))
85 die(regs, str);
86 }
87}
88
89#if defined (CONFIG_XIP_KERNEL) && defined (CONFIG_RISCV_ERRATA_ALTERNATIVE)
90#define __trap_section __section(".xip.traps")
91#else
92#define __trap_section
93#endif
94#define DO_ERROR_INFO(name, signo, code, str) \
95asmlinkage __visible __trap_section void name(struct pt_regs *regs) \
96{ \
97 do_trap_error(regs, signo, code, regs->epc, "Oops - " str); \
98}
99
100DO_ERROR_INFO(do_trap_unknown,
101 SIGILL, ILL_ILLTRP, "unknown exception");
102DO_ERROR_INFO(do_trap_insn_misaligned,
103 SIGBUS, BUS_ADRALN, "instruction address misaligned");
104DO_ERROR_INFO(do_trap_insn_fault,
105 SIGSEGV, SEGV_ACCERR, "instruction access fault");
106DO_ERROR_INFO(do_trap_insn_illegal,
107 SIGILL, ILL_ILLOPC, "illegal instruction");
108DO_ERROR_INFO(do_trap_load_fault,
109 SIGSEGV, SEGV_ACCERR, "load access fault");
110#ifndef CONFIG_RISCV_M_MODE
111DO_ERROR_INFO(do_trap_load_misaligned,
112 SIGBUS, BUS_ADRALN, "Oops - load address misaligned");
113DO_ERROR_INFO(do_trap_store_misaligned,
114 SIGBUS, BUS_ADRALN, "Oops - store (or AMO) address misaligned");
115#else
116int handle_misaligned_load(struct pt_regs *regs);
117int handle_misaligned_store(struct pt_regs *regs);
118
119asmlinkage void __trap_section do_trap_load_misaligned(struct pt_regs *regs)
120{
121 if (!handle_misaligned_load(regs))
122 return;
123 do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
124 "Oops - load address misaligned");
125}
126
127asmlinkage void __trap_section do_trap_store_misaligned(struct pt_regs *regs)
128{
129 if (!handle_misaligned_store(regs))
130 return;
131 do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
132 "Oops - store (or AMO) address misaligned");
133}
134#endif
135DO_ERROR_INFO(do_trap_store_fault,
136 SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault");
137DO_ERROR_INFO(do_trap_ecall_u,
138 SIGILL, ILL_ILLTRP, "environment call from U-mode");
139DO_ERROR_INFO(do_trap_ecall_s,
140 SIGILL, ILL_ILLTRP, "environment call from S-mode");
141DO_ERROR_INFO(do_trap_ecall_m,
142 SIGILL, ILL_ILLTRP, "environment call from M-mode");
143
144static inline unsigned long get_break_insn_length(unsigned long pc)
145{
146 bug_insn_t insn;
147
148 if (get_kernel_nofault(insn, (bug_insn_t *)pc))
149 return 0;
150
151 return GET_INSN_LENGTH(insn);
152}
153
154asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs)
155{
156#ifdef CONFIG_KPROBES
157 if (kprobe_single_step_handler(regs))
158 return;
159
160 if (kprobe_breakpoint_handler(regs))
161 return;
162#endif
163#ifdef CONFIG_UPROBES
164 if (uprobe_single_step_handler(regs))
165 return;
166
167 if (uprobe_breakpoint_handler(regs))
168 return;
169#endif
170 current->thread.bad_cause = regs->cause;
171
172 if (user_mode(regs))
173 force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->epc);
174#ifdef CONFIG_KGDB
175 else if (notify_die(DIE_TRAP, "EBREAK", regs, 0, regs->cause, SIGTRAP)
176 == NOTIFY_STOP)
177 return;
178#endif
179 else if (report_bug(regs->epc, regs) == BUG_TRAP_TYPE_WARN)
180 regs->epc += get_break_insn_length(regs->epc);
181 else
182 die(regs, "Kernel BUG");
183}
184NOKPROBE_SYMBOL(do_trap_break);
185
186#ifdef CONFIG_GENERIC_BUG
187int is_valid_bugaddr(unsigned long pc)
188{
189 bug_insn_t insn;
190
191 if (pc < VMALLOC_START)
192 return 0;
193 if (get_kernel_nofault(insn, (bug_insn_t *)pc))
194 return 0;
195 if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32)
196 return (insn == __BUG_INSN_32);
197 else
198 return ((insn & __COMPRESSED_INSN_MASK) == __BUG_INSN_16);
199}
200#endif
201
202#ifdef CONFIG_VMAP_STACK
203static DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)],
204 overflow_stack)__aligned(16);
205
206
207
208
209long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE/sizeof(long)];
210asmlinkage unsigned long get_overflow_stack(void)
211{
212 return (unsigned long)this_cpu_ptr(overflow_stack) +
213 OVERFLOW_STACK_SIZE;
214}
215
216asmlinkage void handle_bad_stack(struct pt_regs *regs)
217{
218 unsigned long tsk_stk = (unsigned long)current->stack;
219 unsigned long ovf_stk = (unsigned long)this_cpu_ptr(overflow_stack);
220
221 console_verbose();
222
223 pr_emerg("Insufficient stack space to handle exception!\n");
224 pr_emerg("Task stack: [0x%016lx..0x%016lx]\n",
225 tsk_stk, tsk_stk + THREAD_SIZE);
226 pr_emerg("Overflow stack: [0x%016lx..0x%016lx]\n",
227 ovf_stk, ovf_stk + OVERFLOW_STACK_SIZE);
228
229 __show_regs(regs);
230 panic("Kernel stack overflow");
231
232 for (;;)
233 wait_for_interrupt();
234}
235#endif
236
