1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2005-2017 Andes Technology Corporation
3
4 #include <linux/module.h>
5 #include <linux/personality.h>
6 #include <linux/kallsyms.h>
7 #include <linux/hardirq.h>
8 #include <linux/kdebug.h>
9 #include <linux/sched/task_stack.h>
10 #include <linux/uaccess.h>
11 #include <linux/ftrace.h>
12
13 #include <asm/proc-fns.h>
14 #include <asm/unistd.h>
15 #include <asm/fpu.h>
16
17 #include <linux/ptrace.h>
18 #include <nds32_intrinsic.h>
19
20 extern void show_pte(struct mm_struct *mm, unsigned long addr);
21
22 /*
23 * Dump out the contents of some memory nicely...
24 */
dump_mem(const char * lvl,unsigned long bottom,unsigned long top)25 void dump_mem(const char *lvl, unsigned long bottom, unsigned long top)
26 {
27 unsigned long first;
28 mm_segment_t fs;
29 int i;
30
31 /*
32 * We need to switch to kernel mode so that we can use __get_user
33 * to safely read from kernel space. Note that we now dump the
34 * code first, just in case the backtrace kills us.
35 */
36 fs = get_fs();
37 set_fs(KERNEL_DS);
38
39 pr_emerg("%s(0x%08lx to 0x%08lx)\n", lvl, bottom, top);
40
41 for (first = bottom & ~31; first < top; first += 32) {
42 unsigned long p;
43 char str[sizeof(" 12345678") * 8 + 1];
44
45 memset(str, ' ', sizeof(str));
46 str[sizeof(str) - 1] = '\0';
47
48 for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
49 if (p >= bottom && p < top) {
50 unsigned long val;
51 if (__get_user(val, (unsigned long *)p) == 0)
52 sprintf(str + i * 9, " %08lx", val);
53 else
54 sprintf(str + i * 9, " ????????");
55 }
56 }
57 pr_emerg("%s%04lx:%s\n", lvl, first & 0xffff, str);
58 }
59
60 set_fs(fs);
61 }
62
63 EXPORT_SYMBOL(dump_mem);
64
dump_instr(struct pt_regs * regs)65 static void dump_instr(struct pt_regs *regs)
66 {
67 unsigned long addr = instruction_pointer(regs);
68 mm_segment_t fs;
69 char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
70 int i;
71
72 return;
73 /*
74 * We need to switch to kernel mode so that we can use __get_user
75 * to safely read from kernel space. Note that we now dump the
76 * code first, just in case the backtrace kills us.
77 */
78 fs = get_fs();
79 set_fs(KERNEL_DS);
80
81 pr_emerg("Code: ");
82 for (i = -4; i < 1; i++) {
83 unsigned int val, bad;
84
85 bad = __get_user(val, &((u32 *) addr)[i]);
86
87 if (!bad) {
88 p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
89 } else {
90 p += sprintf(p, "bad PC value");
91 break;
92 }
93 }
94 pr_emerg("Code: %s\n", str);
95
96 set_fs(fs);
97 }
98
99 #define LOOP_TIMES (100)
__dump(struct task_struct * tsk,unsigned long * base_reg)100 static void __dump(struct task_struct *tsk, unsigned long *base_reg)
101 {
102 unsigned long ret_addr;
103 int cnt = LOOP_TIMES, graph = 0;
104 pr_emerg("Call Trace:\n");
105 if (!IS_ENABLED(CONFIG_FRAME_POINTER)) {
106 while (!kstack_end(base_reg)) {
107 ret_addr = *base_reg++;
108 if (__kernel_text_address(ret_addr)) {
109 ret_addr = ftrace_graph_ret_addr(
110 tsk, &graph, ret_addr, NULL);
111 print_ip_sym(ret_addr);
112 }
113 if (--cnt < 0)
114 break;
115 }
116 } else {
117 while (!kstack_end((void *)base_reg) &&
118 !((unsigned long)base_reg & 0x3) &&
119 ((unsigned long)base_reg >= TASK_SIZE)) {
120 unsigned long next_fp;
121 ret_addr = base_reg[LP_OFFSET];
122 next_fp = base_reg[FP_OFFSET];
123 if (__kernel_text_address(ret_addr)) {
124
125 ret_addr = ftrace_graph_ret_addr(
126 tsk, &graph, ret_addr, NULL);
127 print_ip_sym(ret_addr);
128 }
129 if (--cnt < 0)
130 break;
131 base_reg = (unsigned long *)next_fp;
132 }
133 }
134 pr_emerg("\n");
135 }
136
show_stack(struct task_struct * tsk,unsigned long * sp)137 void show_stack(struct task_struct *tsk, unsigned long *sp)
138 {
139 unsigned long *base_reg;
140
141 if (!tsk)
142 tsk = current;
143 if (!IS_ENABLED(CONFIG_FRAME_POINTER)) {
144 if (tsk != current)
145 base_reg = (unsigned long *)(tsk->thread.cpu_context.sp);
146 else
147 __asm__ __volatile__("\tori\t%0, $sp, #0\n":"=r"(base_reg));
148 } else {
149 if (tsk != current)
150 base_reg = (unsigned long *)(tsk->thread.cpu_context.fp);
151 else
152 __asm__ __volatile__("\tori\t%0, $fp, #0\n":"=r"(base_reg));
153 }
154 __dump(tsk, base_reg);
155 barrier();
156 }
157
158 DEFINE_SPINLOCK(die_lock);
159
160 /*
161 * This function is protected against re-entrancy.
162 */
die(const char * str,struct pt_regs * regs,int err)163 void die(const char *str, struct pt_regs *regs, int err)
164 {
165 struct task_struct *tsk = current;
166 static int die_counter;
167
168 console_verbose();
169 spin_lock_irq(&die_lock);
170 bust_spinlocks(1);
171
172 pr_emerg("Internal error: %s: %x [#%d]\n", str, err, ++die_counter);
173 print_modules();
174 pr_emerg("CPU: %i\n", smp_processor_id());
175 show_regs(regs);
176 pr_emerg("Process %s (pid: %d, stack limit = 0x%p)\n",
177 tsk->comm, tsk->pid, end_of_stack(tsk));
178
179 if (!user_mode(regs) || in_interrupt()) {
180 dump_mem("Stack: ", regs->sp, (regs->sp + PAGE_SIZE) & PAGE_MASK);
181 dump_instr(regs);
182 dump_stack();
183 }
184
185 bust_spinlocks(0);
186 spin_unlock_irq(&die_lock);
187 do_exit(SIGSEGV);
188 }
189
190 EXPORT_SYMBOL(die);
191
die_if_kernel(const char * str,struct pt_regs * regs,int err)192 void die_if_kernel(const char *str, struct pt_regs *regs, int err)
193 {
194 if (user_mode(regs))
195 return;
196
197 die(str, regs, err);
198 }
199
bad_syscall(int n,struct pt_regs * regs)200 int bad_syscall(int n, struct pt_regs *regs)
201 {
202 if (current->personality != PER_LINUX) {
203 send_sig(SIGSEGV, current, 1);
204 return regs->uregs[0];
205 }
206
207 force_sig_fault(SIGILL, ILL_ILLTRP,
208 (void __user *)instruction_pointer(regs) - 4);
209 die_if_kernel("Oops - bad syscall", regs, n);
210 return regs->uregs[0];
211 }
212
__pte_error(const char * file,int line,unsigned long val)213 void __pte_error(const char *file, int line, unsigned long val)
214 {
215 pr_emerg("%s:%d: bad pte %08lx.\n", file, line, val);
216 }
217
__pmd_error(const char * file,int line,unsigned long val)218 void __pmd_error(const char *file, int line, unsigned long val)
219 {
220 pr_emerg("%s:%d: bad pmd %08lx.\n", file, line, val);
221 }
222
__pgd_error(const char * file,int line,unsigned long val)223 void __pgd_error(const char *file, int line, unsigned long val)
224 {
225 pr_emerg("%s:%d: bad pgd %08lx.\n", file, line, val);
226 }
227
228 extern char *exception_vector, *exception_vector_end;
trap_init(void)229 void __init trap_init(void)
230 {
231 return;
232 }
233
early_trap_init(void)234 void __init early_trap_init(void)
235 {
236 unsigned long ivb = 0;
237 unsigned long base = PAGE_OFFSET;
238
239 memcpy((unsigned long *)base, (unsigned long *)&exception_vector,
240 ((unsigned long)&exception_vector_end -
241 (unsigned long)&exception_vector));
242 ivb = __nds32__mfsr(NDS32_SR_IVB);
243 /* Check platform support. */
244 if (((ivb & IVB_mskNIVIC) >> IVB_offNIVIC) < 2)
245 panic
246 ("IVIC mode is not allowed on the platform with interrupt controller\n");
247 __nds32__mtsr((ivb & ~IVB_mskESZ) | (IVB_valESZ16 << IVB_offESZ) |
248 IVB_BASE, NDS32_SR_IVB);
249 __nds32__mtsr(INT_MASK_INITAIAL_VAL, NDS32_SR_INT_MASK);
250
251 /*
252 * 0x800 = 128 vectors * 16byte.
253 * It should be enough to flush a page.
254 */
255 cpu_cache_wbinval_page(base, true);
256 }
257
send_sigtrap(struct pt_regs * regs,int error_code,int si_code)258 static void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
259 {
260 struct task_struct *tsk = current;
261
262 tsk->thread.trap_no = ENTRY_DEBUG_RELATED;
263 tsk->thread.error_code = error_code;
264
265 force_sig_fault(SIGTRAP, si_code,
266 (void __user *)instruction_pointer(regs));
267 }
268
do_debug_trap(unsigned long entry,unsigned long addr,unsigned long type,struct pt_regs * regs)269 void do_debug_trap(unsigned long entry, unsigned long addr,
270 unsigned long type, struct pt_regs *regs)
271 {
272 if (notify_die(DIE_OOPS, "Oops", regs, addr, type, SIGTRAP)
273 == NOTIFY_STOP)
274 return;
275
276 if (user_mode(regs)) {
277 /* trap_signal */
278 send_sigtrap(regs, 0, TRAP_BRKPT);
279 } else {
280 /* kernel_trap */
281 if (!fixup_exception(regs))
282 die("unexpected kernel_trap", regs, 0);
283 }
284 }
285
unhandled_interruption(struct pt_regs * regs)286 void unhandled_interruption(struct pt_regs *regs)
287 {
288 pr_emerg("unhandled_interruption\n");
289 show_regs(regs);
290 if (!user_mode(regs))
291 do_exit(SIGKILL);
292 force_sig(SIGKILL);
293 }
294
unhandled_exceptions(unsigned long entry,unsigned long addr,unsigned long type,struct pt_regs * regs)295 void unhandled_exceptions(unsigned long entry, unsigned long addr,
296 unsigned long type, struct pt_regs *regs)
297 {
298 pr_emerg("Unhandled Exception: entry: %lx addr:%lx itype:%lx\n", entry,
299 addr, type);
300 show_regs(regs);
301 if (!user_mode(regs))
302 do_exit(SIGKILL);
303 force_sig(SIGKILL);
304 }
305
306 extern int do_page_fault(unsigned long entry, unsigned long addr,
307 unsigned int error_code, struct pt_regs *regs);
308
309 /*
310 * 2:DEF dispatch for TLB MISC exception handler
311 */
312
do_dispatch_tlb_misc(unsigned long entry,unsigned long addr,unsigned long type,struct pt_regs * regs)313 void do_dispatch_tlb_misc(unsigned long entry, unsigned long addr,
314 unsigned long type, struct pt_regs *regs)
315 {
316 type = type & (ITYPE_mskINST | ITYPE_mskETYPE);
317 if ((type & ITYPE_mskETYPE) < 5) {
318 /* Permission exceptions */
319 do_page_fault(entry, addr, type, regs);
320 } else
321 unhandled_exceptions(entry, addr, type, regs);
322 }
323
do_revinsn(struct pt_regs * regs)324 void do_revinsn(struct pt_regs *regs)
325 {
326 pr_emerg("Reserved Instruction\n");
327 show_regs(regs);
328 if (!user_mode(regs))
329 do_exit(SIGILL);
330 force_sig(SIGILL);
331 }
332
333 #ifdef CONFIG_ALIGNMENT_TRAP
334 extern int unalign_access_mode;
335 extern int do_unaligned_access(unsigned long addr, struct pt_regs *regs);
336 #endif
do_dispatch_general(unsigned long entry,unsigned long addr,unsigned long itype,struct pt_regs * regs,unsigned long oipc)337 void do_dispatch_general(unsigned long entry, unsigned long addr,
338 unsigned long itype, struct pt_regs *regs,
339 unsigned long oipc)
340 {
341 unsigned int swid = itype >> ITYPE_offSWID;
342 unsigned long type = itype & (ITYPE_mskINST | ITYPE_mskETYPE);
343 if (type == ETYPE_ALIGNMENT_CHECK) {
344 #ifdef CONFIG_ALIGNMENT_TRAP
345 /* Alignment check */
346 if (user_mode(regs) && unalign_access_mode) {
347 int ret;
348 ret = do_unaligned_access(addr, regs);
349
350 if (ret == 0)
351 return;
352
353 if (ret == -EFAULT)
354 pr_emerg
355 ("Unhandled unaligned access exception\n");
356 }
357 #endif
358 do_page_fault(entry, addr, type, regs);
359 } else if (type == ETYPE_RESERVED_INSTRUCTION) {
360 /* Reserved instruction */
361 do_revinsn(regs);
362 } else if (type == ETYPE_COPROCESSOR) {
363 /* Coprocessor */
364 #if IS_ENABLED(CONFIG_FPU)
365 unsigned int fucop_exist = __nds32__mfsr(NDS32_SR_FUCOP_EXIST);
366 unsigned int cpid = ((itype & ITYPE_mskCPID) >> ITYPE_offCPID);
367
368 if ((cpid == FPU_CPID) &&
369 (fucop_exist & FUCOP_EXIST_mskCP0ISFPU)) {
370 unsigned int subtype = (itype & ITYPE_mskSTYPE);
371
372 if (true == do_fpu_exception(subtype, regs))
373 return;
374 }
375 #endif
376 unhandled_exceptions(entry, addr, type, regs);
377 } else if (type == ETYPE_TRAP && swid == SWID_RAISE_INTERRUPT_LEVEL) {
378 /* trap, used on v3 EDM target debugging workaround */
379 /*
380 * DIPC(OIPC) is passed as parameter before
381 * interrupt is enabled, so the DIPC will not be corrupted
382 * even though interrupts are coming in
383 */
384 /*
385 * 1. update ipc
386 * 2. update pt_regs ipc with oipc
387 * 3. update pt_regs ipsw (clear DEX)
388 */
389 __asm__ volatile ("mtsr %0, $IPC\n\t"::"r" (oipc));
390 regs->ipc = oipc;
391 if (regs->pipsw & PSW_mskDEX) {
392 pr_emerg
393 ("Nested Debug exception is possibly happened\n");
394 pr_emerg("ipc:%08x pipc:%08x\n",
395 (unsigned int)regs->ipc,
396 (unsigned int)regs->pipc);
397 }
398 do_debug_trap(entry, addr, itype, regs);
399 regs->ipsw &= ~PSW_mskDEX;
400 } else
401 unhandled_exceptions(entry, addr, type, regs);
402 }
403