2 * Main exception handling logic.
4 * Copyright 2004-2010 Analog Devices Inc.
6 * Licensed under the GPL-2 or later
10 #include <linux/uaccess.h>
11 #include <linux/module.h>
12 #include <linux/sched/signal.h>
13 #include <asm/traps.h>
15 #include <asm/blackfin.h>
16 #include <asm/irq_handler.h>
17 #include <linux/irq.h>
18 #include <asm/trace.h>
19 #include <asm/fixed_code.h>
20 #include <asm/pseudo_instructions.h>
22 #include <asm/asm-offsets.h>
25 # include <linux/kgdb.h>
27 # define CHK_DEBUGGER_TRAP() \
29 kgdb_handle_exception(trapnr, sig, info.si_code, fp); \
31 # define CHK_DEBUGGER_TRAP_MAYBE() \
34 CHK_DEBUGGER_TRAP(); \
37 # define CHK_DEBUGGER_TRAP() do { } while (0)
38 # define CHK_DEBUGGER_TRAP_MAYBE() do { } while (0)
42 #ifdef CONFIG_DEBUG_VERBOSE
43 #define verbose_printk(fmt, arg...) \
46 #define verbose_printk(fmt, arg...) \
47 ({ if (0) printk(fmt, ##arg); 0; })
50 #if defined(CONFIG_DEBUG_MMRS) || defined(CONFIG_DEBUG_MMRS_MODULE)
52 #ifdef CONFIG_DEBUG_MMRS_MODULE
53 EXPORT_SYMBOL(last_seqstat);
57 /* Initiate the event table handler */
58 void __init trap_init(void)
61 bfin_write_EVT3(trap);
65 static int kernel_mode_regs(struct pt_regs *regs)
67 return regs->ipend & 0xffc0;
70 asmlinkage notrace void trap_c(struct pt_regs *fp)
72 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
75 #ifdef CONFIG_BFIN_PSEUDODBG_INSNS
78 unsigned int cpu = raw_smp_processor_id();
79 const char *strerror = NULL;
82 unsigned long trapnr = fp->seqstat & SEQSTAT_EXCAUSE;
85 #if defined(CONFIG_DEBUG_MMRS) || defined(CONFIG_DEBUG_MMRS_MODULE)
86 last_seqstat = (u32)fp->seqstat;
89 /* Important - be very careful dereferncing pointers - will lead to
90 * double faults if the stack has become corrupt
93 /* trap_c() will be called for exceptions. During exceptions
94 * processing, the pc value should be set with retx value.
95 * With this change we can cleanup some code in signal.c- TODO
97 fp->orig_pc = fp->retx;
98 /* printk("exception: 0x%x, ipend=%x, reti=%x, retx=%x\n",
99 trapnr, fp->ipend, fp->pc, fp->retx); */
101 /* send the appropriate signal to the user program */
104 /* This table works in conjunction with the one in ./mach-common/entry.S
105 * Some exceptions are handled there (in assembly, in exception space)
106 * Some are handled here, (in C, in interrupt space)
107 * Some, like CPLB, are handled in both, where the normal path is
108 * handled in assembly/exception space, and the error path is handled
112 /* 0x00 - Linux Syscall, getting here is an error */
113 /* 0x01 - userspace gdb breakpoint, handled here */
115 info.si_code = TRAP_ILLTRAP;
117 CHK_DEBUGGER_TRAP_MAYBE();
118 /* Check if this is a breakpoint in kernel space */
119 if (kernel_mode_regs(fp))
123 /* 0x03 - User Defined, userspace stack overflow */
125 info.si_code = SEGV_STACKFLOW;
127 strerror = KERN_NOTICE EXC_0x03(KERN_NOTICE);
128 CHK_DEBUGGER_TRAP_MAYBE();
130 /* 0x02 - KGDB initial connection and break signal trap */
133 info.si_code = TRAP_ILLTRAP;
138 /* 0x04 - User Defined */
139 /* 0x05 - User Defined */
140 /* 0x06 - User Defined */
141 /* 0x07 - User Defined */
142 /* 0x08 - User Defined */
143 /* 0x09 - User Defined */
144 /* 0x0A - User Defined */
145 /* 0x0B - User Defined */
146 /* 0x0C - User Defined */
147 /* 0x0D - User Defined */
148 /* 0x0E - User Defined */
149 /* 0x0F - User Defined */
150 /* If we got here, it is most likely that someone was trying to use a
151 * custom exception handler, and it is not actually installed properly
153 case VEC_EXCPT04 ... VEC_EXCPT15:
154 info.si_code = ILL_ILLPARAOP;
156 strerror = KERN_NOTICE EXC_0x04(KERN_NOTICE);
157 CHK_DEBUGGER_TRAP_MAYBE();
159 /* 0x10 HW Single step, handled here */
161 info.si_code = TRAP_STEP;
163 CHK_DEBUGGER_TRAP_MAYBE();
164 /* Check if this is a single step in kernel space */
165 if (kernel_mode_regs(fp))
169 /* 0x11 - Trace Buffer Full, handled here */
171 info.si_code = TRAP_TRACEFLOW;
173 strerror = KERN_NOTICE EXC_0x11(KERN_NOTICE);
174 CHK_DEBUGGER_TRAP_MAYBE();
176 /* 0x12 - Reserved, Caught by default */
177 /* 0x13 - Reserved, Caught by default */
178 /* 0x14 - Reserved, Caught by default */
179 /* 0x15 - Reserved, Caught by default */
180 /* 0x16 - Reserved, Caught by default */
181 /* 0x17 - Reserved, Caught by default */
182 /* 0x18 - Reserved, Caught by default */
183 /* 0x19 - Reserved, Caught by default */
184 /* 0x1A - Reserved, Caught by default */
185 /* 0x1B - Reserved, Caught by default */
186 /* 0x1C - Reserved, Caught by default */
187 /* 0x1D - Reserved, Caught by default */
188 /* 0x1E - Reserved, Caught by default */
189 /* 0x1F - Reserved, Caught by default */
190 /* 0x20 - Reserved, Caught by default */
191 /* 0x21 - Undefined Instruction, handled here */
194 if (kernel_mode_regs(fp)) {
195 switch (report_bug(fp->pc, fp)) {
196 case BUG_TRAP_TYPE_NONE:
198 case BUG_TRAP_TYPE_WARN:
199 dump_bfin_trace_buffer();
202 case BUG_TRAP_TYPE_BUG:
203 /* call to panic() will dump trace, and it is
204 * off at this point, so it won't be clobbered
210 #ifdef CONFIG_BFIN_PSEUDODBG_INSNS
212 * Support for the fake instructions, if the instruction fails,
213 * then just execute a illegal opcode failure (like normal).
214 * Don't support these instructions inside the kernel
216 if (!kernel_mode_regs(fp) && get_instruction(&opcode, (unsigned short *)fp->pc)) {
217 if (execute_pseudodbg_assert(fp, opcode))
219 if (execute_pseudodbg(fp, opcode))
223 info.si_code = ILL_ILLOPC;
225 strerror = KERN_NOTICE EXC_0x21(KERN_NOTICE);
226 CHK_DEBUGGER_TRAP_MAYBE();
228 /* 0x22 - Illegal Instruction Combination, handled here */
230 info.si_code = ILL_ILLPARAOP;
232 strerror = KERN_NOTICE EXC_0x22(KERN_NOTICE);
233 CHK_DEBUGGER_TRAP_MAYBE();
235 /* 0x23 - Data CPLB protection violation, handled here */
237 info.si_code = ILL_CPLB_VI;
239 strerror = KERN_NOTICE EXC_0x23(KERN_NOTICE);
240 CHK_DEBUGGER_TRAP_MAYBE();
242 /* 0x24 - Data access misaligned, handled here */
244 info.si_code = BUS_ADRALN;
246 strerror = KERN_NOTICE EXC_0x24(KERN_NOTICE);
247 CHK_DEBUGGER_TRAP_MAYBE();
249 /* 0x25 - Unrecoverable Event, handled here */
251 info.si_code = ILL_ILLEXCPT;
253 strerror = KERN_NOTICE EXC_0x25(KERN_NOTICE);
254 CHK_DEBUGGER_TRAP_MAYBE();
256 /* 0x26 - Data CPLB Miss, normal case is handled in _cplb_hdr,
257 error case is handled here */
259 info.si_code = BUS_ADRALN;
261 strerror = KERN_NOTICE EXC_0x26(KERN_NOTICE);
263 /* 0x27 - Data CPLB Multiple Hits - Linux Trap Zero, handled here */
265 info.si_code = ILL_CPLB_MULHIT;
267 #ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
268 if (cpu_pda[cpu].dcplb_fault_addr < FIXED_CODE_START)
269 strerror = KERN_NOTICE "NULL pointer access\n";
272 strerror = KERN_NOTICE EXC_0x27(KERN_NOTICE);
273 CHK_DEBUGGER_TRAP_MAYBE();
275 /* 0x28 - Emulation Watchpoint, handled here */
277 info.si_code = TRAP_WATCHPT;
279 pr_debug(EXC_0x28(KERN_DEBUG));
280 CHK_DEBUGGER_TRAP_MAYBE();
281 /* Check if this is a watchpoint in kernel space */
282 if (kernel_mode_regs(fp))
287 /* 0x29 - Instruction fetch access error (535 only) */
288 case VEC_ISTRU_VL: /* ADSP-BF535 only (MH) */
289 info.si_code = BUS_OPFETCH;
291 strerror = KERN_NOTICE "BF535: VEC_ISTRU_VL\n";
292 CHK_DEBUGGER_TRAP_MAYBE();
295 /* 0x29 - Reserved, Caught by default */
297 /* 0x2A - Instruction fetch misaligned, handled here */
299 info.si_code = BUS_ADRALN;
301 strerror = KERN_NOTICE EXC_0x2A(KERN_NOTICE);
302 CHK_DEBUGGER_TRAP_MAYBE();
304 /* 0x2B - Instruction CPLB protection violation, handled here */
306 info.si_code = ILL_CPLB_VI;
308 strerror = KERN_NOTICE EXC_0x2B(KERN_NOTICE);
309 CHK_DEBUGGER_TRAP_MAYBE();
311 /* 0x2C - Instruction CPLB miss, handled in _cplb_hdr */
313 info.si_code = ILL_CPLB_MISS;
315 strerror = KERN_NOTICE EXC_0x2C(KERN_NOTICE);
317 /* 0x2D - Instruction CPLB Multiple Hits, handled here */
318 case VEC_CPLB_I_MHIT:
319 info.si_code = ILL_CPLB_MULHIT;
321 #ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
322 if (cpu_pda[cpu].icplb_fault_addr < FIXED_CODE_START)
323 strerror = KERN_NOTICE "Jump to NULL address\n";
326 strerror = KERN_NOTICE EXC_0x2D(KERN_NOTICE);
327 CHK_DEBUGGER_TRAP_MAYBE();
329 /* 0x2E - Illegal use of Supervisor Resource, handled here */
331 info.si_code = ILL_PRVOPC;
333 strerror = KERN_NOTICE EXC_0x2E(KERN_NOTICE);
334 CHK_DEBUGGER_TRAP_MAYBE();
336 /* 0x2F - Reserved, Caught by default */
337 /* 0x30 - Reserved, Caught by default */
338 /* 0x31 - Reserved, Caught by default */
339 /* 0x32 - Reserved, Caught by default */
340 /* 0x33 - Reserved, Caught by default */
341 /* 0x34 - Reserved, Caught by default */
342 /* 0x35 - Reserved, Caught by default */
343 /* 0x36 - Reserved, Caught by default */
344 /* 0x37 - Reserved, Caught by default */
345 /* 0x38 - Reserved, Caught by default */
346 /* 0x39 - Reserved, Caught by default */
347 /* 0x3A - Reserved, Caught by default */
348 /* 0x3B - Reserved, Caught by default */
349 /* 0x3C - Reserved, Caught by default */
350 /* 0x3D - Reserved, Caught by default */
351 /* 0x3E - Reserved, Caught by default */
352 /* 0x3F - Reserved, Caught by default */
354 info.si_code = BUS_ADRALN;
356 switch (fp->seqstat & SEQSTAT_HWERRCAUSE) {
357 /* System MMR Error */
358 case (SEQSTAT_HWERRCAUSE_SYSTEM_MMR):
359 info.si_code = BUS_ADRALN;
361 strerror = KERN_NOTICE HWC_x2(KERN_NOTICE);
363 /* External Memory Addressing Error */
364 case (SEQSTAT_HWERRCAUSE_EXTERN_ADDR):
365 if (ANOMALY_05000310) {
366 static unsigned long anomaly_rets;
368 if ((fp->pc >= (L1_CODE_START + L1_CODE_LENGTH - 512)) &&
369 (fp->pc < (L1_CODE_START + L1_CODE_LENGTH))) {
371 * A false hardware error will happen while fetching at
372 * the L1 instruction SRAM boundary. Ignore it.
374 anomaly_rets = fp->rets;
376 } else if (fp->rets == anomaly_rets) {
378 * While boundary code returns to a function, at the ret
379 * point, a new false hardware error might occur too based
380 * on tests. Ignore it too.
383 } else if ((fp->rets >= (L1_CODE_START + L1_CODE_LENGTH - 512)) &&
384 (fp->rets < (L1_CODE_START + L1_CODE_LENGTH))) {
386 * If boundary code calls a function, at the entry point,
387 * a new false hardware error maybe happen based on tests.
395 info.si_code = BUS_ADRERR;
397 strerror = KERN_NOTICE HWC_x3(KERN_NOTICE);
399 /* Performance Monitor Overflow */
400 case (SEQSTAT_HWERRCAUSE_PERF_FLOW):
401 strerror = KERN_NOTICE HWC_x12(KERN_NOTICE);
403 /* RAISE 5 instruction */
404 case (SEQSTAT_HWERRCAUSE_RAISE_5):
405 printk(KERN_NOTICE HWC_x18(KERN_NOTICE));
407 default: /* Reserved */
408 printk(KERN_NOTICE HWC_default(KERN_NOTICE));
411 CHK_DEBUGGER_TRAP_MAYBE();
414 * We should be handling all known exception types above,
415 * if we get here we hit a reserved one, so panic
418 info.si_code = ILL_ILLPARAOP;
420 verbose_printk(KERN_EMERG "Caught Unhandled Exception, code = %08lx\n",
421 (fp->seqstat & SEQSTAT_EXCAUSE));
422 CHK_DEBUGGER_TRAP_MAYBE();
428 /* If the fault was caused by a kernel thread, or interrupt handler
429 * we will kernel panic, so the system reboots.
431 if (kernel_mode_regs(fp) || (current && !current->mm)) {
433 oops_in_progress = 1;
436 if (sig != SIGTRAP) {
438 verbose_printk(strerror);
440 dump_bfin_process(fp);
444 /* Print out the trace buffer if it makes sense */
445 #ifndef CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE
446 if (trapnr == VEC_CPLB_I_M || trapnr == VEC_CPLB_M)
447 verbose_printk(KERN_NOTICE "No trace since you do not have "
448 "CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE enabled\n\n");
451 dump_bfin_trace_buffer();
453 if (oops_in_progress) {
454 /* Dump the current kernel stack */
455 verbose_printk(KERN_NOTICE "Kernel Stack\n");
456 show_stack(current, NULL);
458 #ifndef CONFIG_ACCESS_CHECK
459 verbose_printk(KERN_EMERG "Please turn on "
460 "CONFIG_ACCESS_CHECK\n");
462 panic("Kernel exception");
464 #ifdef CONFIG_DEBUG_VERBOSE
465 unsigned long *stack;
466 /* Dump the user space stack */
467 stack = (unsigned long *)rdusp();
468 verbose_printk(KERN_NOTICE "Userspace Stack\n");
469 show_stack(NULL, stack);
475 if (!ipipe_trap_notify(fp->seqstat & 0x3f, fp))
485 info.si_addr = (void __user *)cpu_pda[cpu].dcplb_fault_addr;
488 info.si_addr = (void __user *)fp->pc;
491 force_sig_info(sig, &info, current);
494 if ((ANOMALY_05000461 && trapnr == VEC_HWERR && !access_ok(VERIFY_READ, fp->pc, 8)) ||
495 (ANOMALY_05000281 && trapnr == VEC_HWERR) ||
496 (ANOMALY_05000189 && (trapnr == VEC_CPLB_I_VL || trapnr == VEC_CPLB_VL)))
497 fp->pc = SAFE_USER_INSTRUCTION;
500 trace_buffer_restore(j);
503 asmlinkage void double_fault_c(struct pt_regs *fp)
505 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
507 trace_buffer_save(j);
511 oops_in_progress = 1;
512 #ifdef CONFIG_DEBUG_VERBOSE
513 printk(KERN_EMERG "Double Fault\n");
514 #ifdef CONFIG_DEBUG_DOUBLEFAULT_PRINT
515 if (((long)fp->seqstat & SEQSTAT_EXCAUSE) == VEC_UNCOV) {
516 unsigned int cpu = raw_smp_processor_id();
518 decode_address(buf, cpu_pda[cpu].retx_doublefault);
519 printk(KERN_EMERG "While handling exception (EXCAUSE = 0x%x) at %s:\n",
520 (unsigned int)cpu_pda[cpu].seqstat_doublefault & SEQSTAT_EXCAUSE, buf);
521 decode_address(buf, cpu_pda[cpu].dcplb_doublefault_addr);
522 printk(KERN_NOTICE " DCPLB_FAULT_ADDR: %s\n", buf);
523 decode_address(buf, cpu_pda[cpu].icplb_doublefault_addr);
524 printk(KERN_NOTICE " ICPLB_FAULT_ADDR: %s\n", buf);
526 decode_address(buf, fp->retx);
527 printk(KERN_NOTICE "The instruction at %s caused a double exception\n", buf);
531 dump_bfin_process(fp);
534 dump_bfin_trace_buffer();
537 panic("Double Fault - unrecoverable event");
542 void panic_cplb_error(int cplb_panic, struct pt_regs *fp)
544 switch (cplb_panic) {
545 case CPLB_NO_UNLOCKED:
546 printk(KERN_EMERG "All CPLBs are locked\n");
550 case CPLB_NO_ADDR_MATCH:
552 case CPLB_UNKNOWN_ERR:
553 printk(KERN_EMERG "Unknown CPLB Exception\n");
557 oops_in_progress = 1;
559 dump_bfin_process(fp);
563 panic("Unrecoverable event");
567 int is_valid_bugaddr(unsigned long addr)
571 if (!get_instruction(&opcode, (unsigned short *)addr))
574 return opcode == BFIN_BUG_OPCODE;
579 #ifndef CONFIG_DEBUG_VERBOSE
580 void show_regs(struct pt_regs *fp)