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 #include <linux/pgtable.h> 22 23 #include <asm/delay.h> 24 #include <asm/ptrace.h> 25 #include <asm/oplib.h> 26 #include <asm/page.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 make_task_dead((regs->psr & PSR_PS) ? SIGKILL : SIGSEGV); 90 } 91 92 void do_hw_interrupt(struct pt_regs *regs, unsigned long type) 93 { 94 if(type < 0x80) { 95 /* Sun OS's puke from bad traps, Linux survives! */ 96 printk("Unimplemented Sparc TRAP, type = %02lx\n", type); 97 die_if_kernel("Whee... Hello Mr. Penguin", regs); 98 } 99 100 if(regs->psr & PSR_PS) 101 die_if_kernel("Kernel bad trap", regs); 102 103 force_sig_fault_trapno(SIGILL, ILL_ILLTRP, 104 (void __user *)regs->pc, type - 0x80); 105 } 106 107 void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc, 108 unsigned long psr) 109 { 110 if(psr & PSR_PS) 111 die_if_kernel("Kernel illegal instruction", regs); 112 #ifdef TRAP_DEBUG 113 printk("Ill instr. at pc=%08lx instruction is %08lx\n", 114 regs->pc, *(unsigned long *)regs->pc); 115 #endif 116 117 send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc, current); 118 } 119 120 void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc, 121 unsigned long psr) 122 { 123 if(psr & PSR_PS) 124 die_if_kernel("Penguin instruction from Penguin mode??!?!", regs); 125 send_sig_fault(SIGILL, ILL_PRVOPC, (void __user *)pc, current); 126 } 127 128 /* XXX User may want to be allowed to do this. XXX */ 129 130 void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc, 131 unsigned long psr) 132 { 133 if(regs->psr & PSR_PS) { 134 printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc, 135 regs->u_regs[UREG_RETPC]); 136 die_if_kernel("BOGUS", regs); 137 /* die_if_kernel("Kernel MNA access", regs); */ 138 } 139 #if 0 140 show_regs (regs); 141 instruction_dump ((unsigned long *) regs->pc); 142 printk ("do_MNA!\n"); 143 #endif 144 send_sig_fault(SIGBUS, BUS_ADRALN, 145 /* FIXME: Should dig out mna address */ (void *)0, 146 current); 147 } 148 149 static unsigned long init_fsr = 0x0UL; 150 static unsigned long init_fregs[32] __attribute__ ((aligned (8))) = 151 { ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, 152 ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, 153 ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, 154 ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL }; 155 156 void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc, 157 unsigned long psr) 158 { 159 /* Sanity check... */ 160 if(psr & PSR_PS) 161 die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs); 162 163 put_psr(get_psr() | PSR_EF); /* Allow FPU ops. */ 164 regs->psr |= PSR_EF; 165 #ifndef CONFIG_SMP 166 if(last_task_used_math == current) 167 return; 168 if(last_task_used_math) { 169 /* Other processes fpu state, save away */ 170 struct task_struct *fptask = last_task_used_math; 171 fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr, 172 &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth); 173 } 174 last_task_used_math = current; 175 if(used_math()) { 176 fpload(¤t->thread.float_regs[0], ¤t->thread.fsr); 177 } else { 178 /* Set initial sane state. */ 179 fpload(&init_fregs[0], &init_fsr); 180 set_used_math(); 181 } 182 #else 183 if(!used_math()) { 184 fpload(&init_fregs[0], &init_fsr); 185 set_used_math(); 186 } else { 187 fpload(¤t->thread.float_regs[0], ¤t->thread.fsr); 188 } 189 set_thread_flag(TIF_USEDFPU); 190 #endif 191 } 192 193 static unsigned long fake_regs[32] __attribute__ ((aligned (8))); 194 static unsigned long fake_fsr; 195 static unsigned long fake_queue[32] __attribute__ ((aligned (8))); 196 static unsigned long fake_depth; 197 198 void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc, 199 unsigned long psr) 200 { 201 static int calls; 202 unsigned long fsr; 203 int ret = 0; 204 int code; 205 #ifndef CONFIG_SMP 206 struct task_struct *fpt = last_task_used_math; 207 #else 208 struct task_struct *fpt = current; 209 #endif 210 put_psr(get_psr() | PSR_EF); 211 /* If nobody owns the fpu right now, just clear the 212 * error into our fake static buffer and hope it don't 213 * happen again. Thank you crashme... 214 */ 215 #ifndef CONFIG_SMP 216 if(!fpt) { 217 #else 218 if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) { 219 #endif 220 fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth); 221 regs->psr &= ~PSR_EF; 222 return; 223 } 224 fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr, 225 &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth); 226 #ifdef DEBUG_FPU 227 printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr); 228 #endif 229 230 switch ((fpt->thread.fsr & 0x1c000)) { 231 /* switch on the contents of the ftt [floating point trap type] field */ 232 #ifdef DEBUG_FPU 233 case (1 << 14): 234 printk("IEEE_754_exception\n"); 235 break; 236 #endif 237 case (2 << 14): /* unfinished_FPop (underflow & co) */ 238 case (3 << 14): /* unimplemented_FPop (quad stuff, maybe sqrt) */ 239 ret = do_mathemu(regs, fpt); 240 break; 241 #ifdef DEBUG_FPU 242 case (4 << 14): 243 printk("sequence_error (OS bug...)\n"); 244 break; 245 case (5 << 14): 246 printk("hardware_error (uhoh!)\n"); 247 break; 248 case (6 << 14): 249 printk("invalid_fp_register (user error)\n"); 250 break; 251 #endif /* DEBUG_FPU */ 252 } 253 /* If we successfully emulated the FPop, we pretend the trap never happened :-> */ 254 if (ret) { 255 fpload(¤t->thread.float_regs[0], ¤t->thread.fsr); 256 return; 257 } 258 /* nope, better SIGFPE the offending process... */ 259 260 #ifdef CONFIG_SMP 261 clear_tsk_thread_flag(fpt, TIF_USEDFPU); 262 #endif 263 if(psr & PSR_PS) { 264 /* The first fsr store/load we tried trapped, 265 * the second one will not (we hope). 266 */ 267 printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n", 268 regs->pc); 269 regs->pc = regs->npc; 270 regs->npc += 4; 271 calls++; 272 if(calls > 2) 273 die_if_kernel("Too many Penguin-FPU traps from kernel mode", 274 regs); 275 return; 276 } 277 278 fsr = fpt->thread.fsr; 279 code = FPE_FLTUNK; 280 if ((fsr & 0x1c000) == (1 << 14)) { 281 if (fsr & 0x10) 282 code = FPE_FLTINV; 283 else if (fsr & 0x08) 284 code = FPE_FLTOVF; 285 else if (fsr & 0x04) 286 code = FPE_FLTUND; 287 else if (fsr & 0x02) 288 code = FPE_FLTDIV; 289 else if (fsr & 0x01) 290 code = FPE_FLTRES; 291 } 292 send_sig_fault(SIGFPE, code, (void __user *)pc, fpt); 293 #ifndef CONFIG_SMP 294 last_task_used_math = NULL; 295 #endif 296 regs->psr &= ~PSR_EF; 297 if(calls > 0) 298 calls=0; 299 } 300 301 void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc, 302 unsigned long psr) 303 { 304 if(psr & PSR_PS) 305 die_if_kernel("Penguin overflow trap from kernel mode", regs); 306 send_sig_fault(SIGEMT, EMT_TAGOVF, (void __user *)pc, current); 307 } 308 309 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc, 310 unsigned long psr) 311 { 312 #ifdef TRAP_DEBUG 313 printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n", 314 pc, npc, psr); 315 #endif 316 if(psr & PSR_PS) 317 panic("Tell me what a watchpoint trap is, and I'll then deal " 318 "with such a beast..."); 319 } 320 321 void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc, 322 unsigned long psr) 323 { 324 #ifdef TRAP_DEBUG 325 printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n", 326 pc, npc, psr); 327 #endif 328 force_sig_fault(SIGBUS, BUS_OBJERR, (void __user *)pc); 329 } 330 331 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc, 332 unsigned long psr) 333 { 334 send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, current); 335 } 336 337 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc, 338 unsigned long psr) 339 { 340 #ifdef TRAP_DEBUG 341 printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n", 342 pc, npc, psr); 343 #endif 344 send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, current); 345 } 346 347 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc, 348 unsigned long psr) 349 { 350 send_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)pc, current); 351 } 352 353 #ifdef CONFIG_DEBUG_BUGVERBOSE 354 void do_BUG(const char *file, int line) 355 { 356 // bust_spinlocks(1); XXX Not in our original BUG() 357 printk("kernel BUG at %s:%d!\n", file, line); 358 } 359 EXPORT_SYMBOL(do_BUG); 360 #endif 361 362 /* Since we have our mappings set up, on multiprocessors we can spin them 363 * up here so that timer interrupts work during initialization. 364 */ 365 366 void trap_init(void) 367 { 368 extern void thread_info_offsets_are_bolixed_pete(void); 369 370 /* Force linker to barf if mismatched */ 371 if (TI_UWINMASK != offsetof(struct thread_info, uwinmask) || 372 TI_TASK != offsetof(struct thread_info, task) || 373 TI_FLAGS != offsetof(struct thread_info, flags) || 374 TI_CPU != offsetof(struct thread_info, cpu) || 375 TI_PREEMPT != offsetof(struct thread_info, preempt_count) || 376 TI_SOFTIRQ != offsetof(struct thread_info, softirq_count) || 377 TI_HARDIRQ != offsetof(struct thread_info, hardirq_count) || 378 TI_KSP != offsetof(struct thread_info, ksp) || 379 TI_KPC != offsetof(struct thread_info, kpc) || 380 TI_KPSR != offsetof(struct thread_info, kpsr) || 381 TI_KWIM != offsetof(struct thread_info, kwim) || 382 TI_REG_WINDOW != offsetof(struct thread_info, reg_window) || 383 TI_RWIN_SPTRS != offsetof(struct thread_info, rwbuf_stkptrs) || 384 TI_W_SAVED != offsetof(struct thread_info, w_saved)) 385 thread_info_offsets_are_bolixed_pete(); 386 387 /* Attach to the address space of init_task. */ 388 mmgrab(&init_mm); 389 current->active_mm = &init_mm; 390 391 /* NOTE: Other cpus have this done as they are started 392 * up on SMP. 393 */ 394 } 395