1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * arch/sparc/kernel/traps.c 4 * 5 * Copyright 1995, 2008 David S. Miller (davem@davemloft.net) 6 * Copyright 2000 Jakub Jelinek (jakub@redhat.com) 7 */ 8 9 /* 10 * I hate traps on the sparc, grrr... 11 */ 12 13 #include <linux/sched/mm.h> 14 #include <linux/sched/debug.h> 15 #include <linux/mm_types.h> 16 #include <linux/kernel.h> 17 #include <linux/signal.h> 18 #include <linux/smp.h> 19 #include <linux/kdebug.h> 20 #include <linux/export.h> 21 22 #include <asm/delay.h> 23 #include <asm/ptrace.h> 24 #include <asm/oplib.h> 25 #include <asm/page.h> 26 #include <asm/pgtable.h> 27 #include <asm/unistd.h> 28 #include <asm/traps.h> 29 30 #include "entry.h" 31 #include "kernel.h" 32 33 /* #define TRAP_DEBUG */ 34 35 static void instruction_dump(unsigned long *pc) 36 { 37 int i; 38 39 if((((unsigned long) pc) & 3)) 40 return; 41 42 for(i = -3; i < 6; i++) 43 printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>'); 44 printk("\n"); 45 } 46 47 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t") 48 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t") 49 50 void __noreturn die_if_kernel(char *str, struct pt_regs *regs) 51 { 52 static int die_counter; 53 int count = 0; 54 55 /* Amuse the user. */ 56 printk( 57 " \\|/ ____ \\|/\n" 58 " \"@'/ ,. \\`@\"\n" 59 " /_| \\__/ |_\\\n" 60 " \\__U_/\n"); 61 62 printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter); 63 show_regs(regs); 64 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 65 66 __SAVE; __SAVE; __SAVE; __SAVE; 67 __SAVE; __SAVE; __SAVE; __SAVE; 68 __RESTORE; __RESTORE; __RESTORE; __RESTORE; 69 __RESTORE; __RESTORE; __RESTORE; __RESTORE; 70 71 { 72 struct reg_window32 *rw = (struct reg_window32 *)regs->u_regs[UREG_FP]; 73 74 /* Stop the back trace when we hit userland or we 75 * find some badly aligned kernel stack. Set an upper 76 * bound in case our stack is trashed and we loop. 77 */ 78 while(rw && 79 count++ < 30 && 80 (((unsigned long) rw) >= PAGE_OFFSET) && 81 !(((unsigned long) rw) & 0x7)) { 82 printk("Caller[%08lx]: %pS\n", rw->ins[7], 83 (void *) rw->ins[7]); 84 rw = (struct reg_window32 *)rw->ins[6]; 85 } 86 } 87 printk("Instruction DUMP:"); 88 instruction_dump ((unsigned long *) regs->pc); 89 if(regs->psr & PSR_PS) 90 do_exit(SIGKILL); 91 do_exit(SIGSEGV); 92 } 93 94 void do_hw_interrupt(struct pt_regs *regs, unsigned long type) 95 { 96 siginfo_t info; 97 98 if(type < 0x80) { 99 /* Sun OS's puke from bad traps, Linux survives! */ 100 printk("Unimplemented Sparc TRAP, type = %02lx\n", type); 101 die_if_kernel("Whee... Hello Mr. Penguin", regs); 102 } 103 104 if(regs->psr & PSR_PS) 105 die_if_kernel("Kernel bad trap", regs); 106 107 info.si_signo = SIGILL; 108 info.si_errno = 0; 109 info.si_code = ILL_ILLTRP; 110 info.si_addr = (void __user *)regs->pc; 111 info.si_trapno = type - 0x80; 112 force_sig_info(SIGILL, &info, current); 113 } 114 115 void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc, 116 unsigned long psr) 117 { 118 siginfo_t info; 119 120 if(psr & PSR_PS) 121 die_if_kernel("Kernel illegal instruction", regs); 122 #ifdef TRAP_DEBUG 123 printk("Ill instr. at pc=%08lx instruction is %08lx\n", 124 regs->pc, *(unsigned long *)regs->pc); 125 #endif 126 127 info.si_signo = SIGILL; 128 info.si_errno = 0; 129 info.si_code = ILL_ILLOPC; 130 info.si_addr = (void __user *)pc; 131 info.si_trapno = 0; 132 send_sig_info(SIGILL, &info, current); 133 } 134 135 void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc, 136 unsigned long psr) 137 { 138 siginfo_t info; 139 140 if(psr & PSR_PS) 141 die_if_kernel("Penguin instruction from Penguin mode??!?!", regs); 142 info.si_signo = SIGILL; 143 info.si_errno = 0; 144 info.si_code = ILL_PRVOPC; 145 info.si_addr = (void __user *)pc; 146 info.si_trapno = 0; 147 send_sig_info(SIGILL, &info, current); 148 } 149 150 /* XXX User may want to be allowed to do this. XXX */ 151 152 void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc, 153 unsigned long psr) 154 { 155 siginfo_t info; 156 157 if(regs->psr & PSR_PS) { 158 printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc, 159 regs->u_regs[UREG_RETPC]); 160 die_if_kernel("BOGUS", regs); 161 /* die_if_kernel("Kernel MNA access", regs); */ 162 } 163 #if 0 164 show_regs (regs); 165 instruction_dump ((unsigned long *) regs->pc); 166 printk ("do_MNA!\n"); 167 #endif 168 info.si_signo = SIGBUS; 169 info.si_errno = 0; 170 info.si_code = BUS_ADRALN; 171 info.si_addr = /* FIXME: Should dig out mna address */ (void *)0; 172 info.si_trapno = 0; 173 send_sig_info(SIGBUS, &info, current); 174 } 175 176 static unsigned long init_fsr = 0x0UL; 177 static unsigned long init_fregs[32] __attribute__ ((aligned (8))) = 178 { ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, 179 ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, 180 ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, 181 ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL }; 182 183 void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc, 184 unsigned long psr) 185 { 186 /* Sanity check... */ 187 if(psr & PSR_PS) 188 die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs); 189 190 put_psr(get_psr() | PSR_EF); /* Allow FPU ops. */ 191 regs->psr |= PSR_EF; 192 #ifndef CONFIG_SMP 193 if(last_task_used_math == current) 194 return; 195 if(last_task_used_math) { 196 /* Other processes fpu state, save away */ 197 struct task_struct *fptask = last_task_used_math; 198 fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr, 199 &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth); 200 } 201 last_task_used_math = current; 202 if(used_math()) { 203 fpload(¤t->thread.float_regs[0], ¤t->thread.fsr); 204 } else { 205 /* Set initial sane state. */ 206 fpload(&init_fregs[0], &init_fsr); 207 set_used_math(); 208 } 209 #else 210 if(!used_math()) { 211 fpload(&init_fregs[0], &init_fsr); 212 set_used_math(); 213 } else { 214 fpload(¤t->thread.float_regs[0], ¤t->thread.fsr); 215 } 216 set_thread_flag(TIF_USEDFPU); 217 #endif 218 } 219 220 static unsigned long fake_regs[32] __attribute__ ((aligned (8))); 221 static unsigned long fake_fsr; 222 static unsigned long fake_queue[32] __attribute__ ((aligned (8))); 223 static unsigned long fake_depth; 224 225 void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc, 226 unsigned long psr) 227 { 228 static int calls; 229 siginfo_t info; 230 unsigned long fsr; 231 int ret = 0; 232 #ifndef CONFIG_SMP 233 struct task_struct *fpt = last_task_used_math; 234 #else 235 struct task_struct *fpt = current; 236 #endif 237 put_psr(get_psr() | PSR_EF); 238 /* If nobody owns the fpu right now, just clear the 239 * error into our fake static buffer and hope it don't 240 * happen again. Thank you crashme... 241 */ 242 #ifndef CONFIG_SMP 243 if(!fpt) { 244 #else 245 if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) { 246 #endif 247 fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth); 248 regs->psr &= ~PSR_EF; 249 return; 250 } 251 fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr, 252 &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth); 253 #ifdef DEBUG_FPU 254 printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr); 255 #endif 256 257 switch ((fpt->thread.fsr & 0x1c000)) { 258 /* switch on the contents of the ftt [floating point trap type] field */ 259 #ifdef DEBUG_FPU 260 case (1 << 14): 261 printk("IEEE_754_exception\n"); 262 break; 263 #endif 264 case (2 << 14): /* unfinished_FPop (underflow & co) */ 265 case (3 << 14): /* unimplemented_FPop (quad stuff, maybe sqrt) */ 266 ret = do_mathemu(regs, fpt); 267 break; 268 #ifdef DEBUG_FPU 269 case (4 << 14): 270 printk("sequence_error (OS bug...)\n"); 271 break; 272 case (5 << 14): 273 printk("hardware_error (uhoh!)\n"); 274 break; 275 case (6 << 14): 276 printk("invalid_fp_register (user error)\n"); 277 break; 278 #endif /* DEBUG_FPU */ 279 } 280 /* If we successfully emulated the FPop, we pretend the trap never happened :-> */ 281 if (ret) { 282 fpload(¤t->thread.float_regs[0], ¤t->thread.fsr); 283 return; 284 } 285 /* nope, better SIGFPE the offending process... */ 286 287 #ifdef CONFIG_SMP 288 clear_tsk_thread_flag(fpt, TIF_USEDFPU); 289 #endif 290 if(psr & PSR_PS) { 291 /* The first fsr store/load we tried trapped, 292 * the second one will not (we hope). 293 */ 294 printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n", 295 regs->pc); 296 regs->pc = regs->npc; 297 regs->npc += 4; 298 calls++; 299 if(calls > 2) 300 die_if_kernel("Too many Penguin-FPU traps from kernel mode", 301 regs); 302 return; 303 } 304 305 fsr = fpt->thread.fsr; 306 info.si_signo = SIGFPE; 307 info.si_errno = 0; 308 info.si_addr = (void __user *)pc; 309 info.si_trapno = 0; 310 info.si_code = FPE_FIXME; 311 if ((fsr & 0x1c000) == (1 << 14)) { 312 if (fsr & 0x10) 313 info.si_code = FPE_FLTINV; 314 else if (fsr & 0x08) 315 info.si_code = FPE_FLTOVF; 316 else if (fsr & 0x04) 317 info.si_code = FPE_FLTUND; 318 else if (fsr & 0x02) 319 info.si_code = FPE_FLTDIV; 320 else if (fsr & 0x01) 321 info.si_code = FPE_FLTRES; 322 } 323 send_sig_info(SIGFPE, &info, fpt); 324 #ifndef CONFIG_SMP 325 last_task_used_math = NULL; 326 #endif 327 regs->psr &= ~PSR_EF; 328 if(calls > 0) 329 calls=0; 330 } 331 332 void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc, 333 unsigned long psr) 334 { 335 siginfo_t info; 336 337 if(psr & PSR_PS) 338 die_if_kernel("Penguin overflow trap from kernel mode", regs); 339 info.si_signo = SIGEMT; 340 info.si_errno = 0; 341 info.si_code = EMT_TAGOVF; 342 info.si_addr = (void __user *)pc; 343 info.si_trapno = 0; 344 send_sig_info(SIGEMT, &info, current); 345 } 346 347 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc, 348 unsigned long psr) 349 { 350 #ifdef TRAP_DEBUG 351 printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n", 352 pc, npc, psr); 353 #endif 354 if(psr & PSR_PS) 355 panic("Tell me what a watchpoint trap is, and I'll then deal " 356 "with such a beast..."); 357 } 358 359 void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc, 360 unsigned long psr) 361 { 362 siginfo_t info; 363 364 #ifdef TRAP_DEBUG 365 printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n", 366 pc, npc, psr); 367 #endif 368 info.si_signo = SIGBUS; 369 info.si_errno = 0; 370 info.si_code = BUS_OBJERR; 371 info.si_addr = (void __user *)pc; 372 info.si_trapno = 0; 373 force_sig_info(SIGBUS, &info, current); 374 } 375 376 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc, 377 unsigned long psr) 378 { 379 siginfo_t info; 380 381 info.si_signo = SIGILL; 382 info.si_errno = 0; 383 info.si_code = ILL_COPROC; 384 info.si_addr = (void __user *)pc; 385 info.si_trapno = 0; 386 send_sig_info(SIGILL, &info, current); 387 } 388 389 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc, 390 unsigned long psr) 391 { 392 siginfo_t info; 393 394 #ifdef TRAP_DEBUG 395 printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n", 396 pc, npc, psr); 397 #endif 398 info.si_signo = SIGILL; 399 info.si_errno = 0; 400 info.si_code = ILL_COPROC; 401 info.si_addr = (void __user *)pc; 402 info.si_trapno = 0; 403 send_sig_info(SIGILL, &info, current); 404 } 405 406 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc, 407 unsigned long psr) 408 { 409 siginfo_t info; 410 411 info.si_signo = SIGFPE; 412 info.si_errno = 0; 413 info.si_code = FPE_INTDIV; 414 info.si_addr = (void __user *)pc; 415 info.si_trapno = 0; 416 send_sig_info(SIGFPE, &info, current); 417 } 418 419 #ifdef CONFIG_DEBUG_BUGVERBOSE 420 void do_BUG(const char *file, int line) 421 { 422 // bust_spinlocks(1); XXX Not in our original BUG() 423 printk("kernel BUG at %s:%d!\n", file, line); 424 } 425 EXPORT_SYMBOL(do_BUG); 426 #endif 427 428 /* Since we have our mappings set up, on multiprocessors we can spin them 429 * up here so that timer interrupts work during initialization. 430 */ 431 432 void trap_init(void) 433 { 434 extern void thread_info_offsets_are_bolixed_pete(void); 435 436 /* Force linker to barf if mismatched */ 437 if (TI_UWINMASK != offsetof(struct thread_info, uwinmask) || 438 TI_TASK != offsetof(struct thread_info, task) || 439 TI_FLAGS != offsetof(struct thread_info, flags) || 440 TI_CPU != offsetof(struct thread_info, cpu) || 441 TI_PREEMPT != offsetof(struct thread_info, preempt_count) || 442 TI_SOFTIRQ != offsetof(struct thread_info, softirq_count) || 443 TI_HARDIRQ != offsetof(struct thread_info, hardirq_count) || 444 TI_KSP != offsetof(struct thread_info, ksp) || 445 TI_KPC != offsetof(struct thread_info, kpc) || 446 TI_KPSR != offsetof(struct thread_info, kpsr) || 447 TI_KWIM != offsetof(struct thread_info, kwim) || 448 TI_REG_WINDOW != offsetof(struct thread_info, reg_window) || 449 TI_RWIN_SPTRS != offsetof(struct thread_info, rwbuf_stkptrs) || 450 TI_W_SAVED != offsetof(struct thread_info, w_saved)) 451 thread_info_offsets_are_bolixed_pete(); 452 453 /* Attach to the address space of init_task. */ 454 mmgrab(&init_mm); 455 current->active_mm = &init_mm; 456 457 /* NOTE: Other cpus have this done as they are started 458 * up on SMP. 459 */ 460 } 461