1// SPDX-License-Identifier: GPL-2.0
  2// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
  3
  4#include <linux/sched.h>
  5#include <linux/signal.h>
  6#include <linux/kernel.h>
  7#include <linux/mm.h>
  8#include <linux/module.h>
  9#include <linux/user.h>
 10#include <linux/string.h>
 11#include <linux/linkage.h>
 12#include <linux/init.h>
 13#include <linux/ptrace.h>
 14#include <linux/kallsyms.h>
 15#include <linux/rtc.h>
 16#include <linux/uaccess.h>
 17#include <linux/kprobes.h>
 18#include <linux/kdebug.h>
 19#include <linux/sched/debug.h>
 20
 21#include <asm/setup.h>
 22#include <asm/traps.h>
 23#include <asm/pgalloc.h>
 24#include <asm/siginfo.h>
 25
 26#include <asm/mmu_context.h>
 27
 28#ifdef CONFIG_CPU_HAS_FPU
 29#include <abi/fpu.h>
 30#endif
 31
 32int show_unhandled_signals = 1;
 33
 34/* Defined in entry.S */
 35asmlinkage void csky_trap(void);
 36
 37asmlinkage void csky_systemcall(void);
 38asmlinkage void csky_cmpxchg(void);
 39asmlinkage void csky_get_tls(void);
 40asmlinkage void csky_irq(void);
 41
 42asmlinkage void csky_tlbinvalidl(void);
 43asmlinkage void csky_tlbinvalids(void);
 44asmlinkage void csky_tlbmodified(void);
 45
 46/* Defined in head.S */
 47asmlinkage void _start_smp_secondary(void);
 48
 49void __init pre_trap_init(void)
 50{
 51	int i;
 52
 53	mtcr("vbr", vec_base);
 54
 55	for (i = 1; i < 128; i++)
 56		VEC_INIT(i, csky_trap);
 57}
 58
 59void __init trap_init(void)
 60{
 61	VEC_INIT(VEC_AUTOVEC, csky_irq);
 62
 63	/* setup trap0 trap2 trap3 */
 64	VEC_INIT(VEC_TRAP0, csky_systemcall);
 65	VEC_INIT(VEC_TRAP2, csky_cmpxchg);
 66	VEC_INIT(VEC_TRAP3, csky_get_tls);
 67
 68	/* setup MMU TLB exception */
 69	VEC_INIT(VEC_TLBINVALIDL, csky_tlbinvalidl);
 70	VEC_INIT(VEC_TLBINVALIDS, csky_tlbinvalids);
 71	VEC_INIT(VEC_TLBMODIFIED, csky_tlbmodified);
 72
 73#ifdef CONFIG_CPU_HAS_FPU
 74	init_fpu();
 75#endif
 76
 77#ifdef CONFIG_SMP
 78	mtcr("cr<28, 0>", virt_to_phys(vec_base));
 79
 80	VEC_INIT(VEC_RESET, (void *)virt_to_phys(_start_smp_secondary));
 81#endif
 82}
 83
 84static DEFINE_SPINLOCK(die_lock);
 85
 86void die(struct pt_regs *regs, const char *str)
 87{
 88	static int die_counter;
 89	int ret;
 90
 91	oops_enter();
 92
 93	spin_lock_irq(&die_lock);
 94	console_verbose();
 95	bust_spinlocks(1);
 96
 97	pr_emerg("%s [#%d]\n", str, ++die_counter);
 98	print_modules();
 99	show_regs(regs);
100	show_stack(current, (unsigned long *)regs->regs[4], KERN_INFO);
101
102	ret = notify_die(DIE_OOPS, str, regs, 0, trap_no(regs), SIGSEGV);
103
104	bust_spinlocks(0);
105	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
106	spin_unlock_irq(&die_lock);
107	oops_exit();
108
109	if (in_interrupt())
110		panic("Fatal exception in interrupt");
111	if (panic_on_oops)
112		panic("Fatal exception");
113	if (ret != NOTIFY_STOP)
114		do_exit(SIGSEGV);
115}
116
117void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr)
118{
119	struct task_struct *tsk = current;
120
121	if (show_unhandled_signals && unhandled_signal(tsk, signo)
122	    && printk_ratelimit()) {
123		pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x%08lx",
124			tsk->comm, task_pid_nr(tsk), signo, code, addr);
125		print_vma_addr(KERN_CONT " in ", instruction_pointer(regs));
126		pr_cont("\n");
127		show_regs(regs);
128	}
129
130	force_sig_fault(signo, code, (void __user *)addr);
131}
132
133static void do_trap_error(struct pt_regs *regs, int signo, int code,
134	unsigned long addr, const char *str)
135{
136	current->thread.trap_no = trap_no(regs);
137
138	if (user_mode(regs)) {
139		do_trap(regs, signo, code, addr);
140	} else {
141		if (!fixup_exception(regs))
142			die(regs, str);
143	}
144}
145
146#define DO_ERROR_INFO(name, signo, code, str)				\
147asmlinkage __visible void name(struct pt_regs *regs)			\
148{									\
149	do_trap_error(regs, signo, code, regs->pc, "Oops - " str);	\
150}
151
152DO_ERROR_INFO(do_trap_unknown,
153	SIGILL, ILL_ILLTRP, "unknown exception");
154DO_ERROR_INFO(do_trap_zdiv,
155	SIGFPE, FPE_INTDIV, "error zero div exception");
156DO_ERROR_INFO(do_trap_buserr,
157	SIGSEGV, ILL_ILLADR, "error bus error exception");
158
159asmlinkage void do_trap_misaligned(struct pt_regs *regs)
160{
161#ifdef CONFIG_CPU_NEED_SOFTALIGN
162	csky_alignment(regs);
163#else
164	current->thread.trap_no = trap_no(regs);
165	do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->pc,
166		      "Oops - load/store address misaligned");
167#endif
168}
169
170asmlinkage void do_trap_bkpt(struct pt_regs *regs)
171{
172#ifdef CONFIG_KPROBES
173	if (kprobe_single_step_handler(regs))
174		return;
175#endif
176#ifdef CONFIG_UPROBES
177	if (uprobe_single_step_handler(regs))
178		return;
179#endif
180	if (user_mode(regs)) {
181		send_sig(SIGTRAP, current, 0);
182		return;
183	}
184
185	do_trap_error(regs, SIGILL, ILL_ILLTRP, regs->pc,
186		      "Oops - illegal trap exception");
187}
188
189asmlinkage void do_trap_illinsn(struct pt_regs *regs)
190{
191	current->thread.trap_no = trap_no(regs);
192
193#ifdef CONFIG_KPROBES
194	if (kprobe_breakpoint_handler(regs))
195		return;
196#endif
197#ifdef CONFIG_UPROBES
198	if (uprobe_breakpoint_handler(regs))
199		return;
200#endif
201#ifndef CONFIG_CPU_NO_USER_BKPT
202	if (*(uint16_t *)instruction_pointer(regs) != USR_BKPT) {
203		send_sig(SIGTRAP, current, 0);
204		return;
205	}
206#endif
207
208	do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->pc,
209		      "Oops - illegal instruction exception");
210}
211
212asmlinkage void do_trap_fpe(struct pt_regs *regs)
213{
214#ifdef CONFIG_CPU_HAS_FP
215	return fpu_fpe(regs);
216#else
217	do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->pc,
218		      "Oops - fpu instruction exception");
219#endif
220}
221
222asmlinkage void do_trap_priv(struct pt_regs *regs)
223{
224#ifdef CONFIG_CPU_HAS_FP
225	if (user_mode(regs) && fpu_libc_helper(regs))
226		return;
227#endif
228	do_trap_error(regs, SIGILL, ILL_PRVOPC, regs->pc,
229		      "Oops - illegal privileged exception");
230}
231
232asmlinkage void trap_c(struct pt_regs *regs)
233{
234	switch (trap_no(regs)) {
235	case VEC_ZERODIV:
236		do_trap_zdiv(regs);
237		break;
238	case VEC_TRACE:
239		do_trap_bkpt(regs);
240		break;
241	case VEC_ILLEGAL:
242		do_trap_illinsn(regs);
243		break;
244	case VEC_TRAP1:
245	case VEC_BREAKPOINT:
246		do_trap_bkpt(regs);
247		break;
248	case VEC_ACCESS:
249		do_trap_buserr(regs);
250		break;
251	case VEC_ALIGN:
252		do_trap_misaligned(regs);
253		break;
254	case VEC_FPE:
255		do_trap_fpe(regs);
256		break;
257	case VEC_PRIV:
258		do_trap_priv(regs);
259		break;
260	default:
261		do_trap_unknown(regs);
262		break;
263	}
264}