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