1 /*
2 * arch/sh/kernel/process_64.c
3 *
4 * This file handles the architecture-dependent parts of process handling..
5 *
6 * Copyright (C) 2000, 2001 Paolo Alberelli
7 * Copyright (C) 2003 - 2007 Paul Mundt
8 * Copyright (C) 2003, 2004 Richard Curnow
9 *
10 * Started from SH3/4 version:
11 * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
12 *
13 * In turn started from i386 version:
14 * Copyright (C) 1995 Linus Torvalds
15 *
16 * This file is subject to the terms and conditions of the GNU General Public
17 * License. See the file "COPYING" in the main directory of this archive
18 * for more details.
19 */
20 #include <linux/mm.h>
21 #include <linux/fs.h>
22 #include <linux/ptrace.h>
23 #include <linux/reboot.h>
24 #include <linux/slab.h>
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/io.h>
28 #include <linux/sched/debug.h>
29 #include <linux/sched/task.h>
30 #include <linux/sched/task_stack.h>
31 #include <asm/syscalls.h>
32 #include <linux/uaccess.h>
33 #include <asm/pgtable.h>
34 #include <asm/mmu_context.h>
35 #include <asm/fpu.h>
36 #include <asm/switch_to.h>
37
38 struct task_struct *last_task_used_math = NULL;
39 struct pt_regs fake_swapper_regs = { 0, };
40
show_regs(struct pt_regs * regs)41 void show_regs(struct pt_regs *regs)
42 {
43 unsigned long long ah, al, bh, bl, ch, cl;
44
45 printk("\n");
46 show_regs_print_info(KERN_DEFAULT);
47
48 ah = (regs->pc) >> 32;
49 al = (regs->pc) & 0xffffffff;
50 bh = (regs->regs[18]) >> 32;
51 bl = (regs->regs[18]) & 0xffffffff;
52 ch = (regs->regs[15]) >> 32;
53 cl = (regs->regs[15]) & 0xffffffff;
54 printk("PC : %08Lx%08Lx LINK: %08Lx%08Lx SP : %08Lx%08Lx\n",
55 ah, al, bh, bl, ch, cl);
56
57 ah = (regs->sr) >> 32;
58 al = (regs->sr) & 0xffffffff;
59 asm volatile ("getcon " __TEA ", %0" : "=r" (bh));
60 asm volatile ("getcon " __TEA ", %0" : "=r" (bl));
61 bh = (bh) >> 32;
62 bl = (bl) & 0xffffffff;
63 asm volatile ("getcon " __KCR0 ", %0" : "=r" (ch));
64 asm volatile ("getcon " __KCR0 ", %0" : "=r" (cl));
65 ch = (ch) >> 32;
66 cl = (cl) & 0xffffffff;
67 printk("SR : %08Lx%08Lx TEA : %08Lx%08Lx KCR0: %08Lx%08Lx\n",
68 ah, al, bh, bl, ch, cl);
69
70 ah = (regs->regs[0]) >> 32;
71 al = (regs->regs[0]) & 0xffffffff;
72 bh = (regs->regs[1]) >> 32;
73 bl = (regs->regs[1]) & 0xffffffff;
74 ch = (regs->regs[2]) >> 32;
75 cl = (regs->regs[2]) & 0xffffffff;
76 printk("R0 : %08Lx%08Lx R1 : %08Lx%08Lx R2 : %08Lx%08Lx\n",
77 ah, al, bh, bl, ch, cl);
78
79 ah = (regs->regs[3]) >> 32;
80 al = (regs->regs[3]) & 0xffffffff;
81 bh = (regs->regs[4]) >> 32;
82 bl = (regs->regs[4]) & 0xffffffff;
83 ch = (regs->regs[5]) >> 32;
84 cl = (regs->regs[5]) & 0xffffffff;
85 printk("R3 : %08Lx%08Lx R4 : %08Lx%08Lx R5 : %08Lx%08Lx\n",
86 ah, al, bh, bl, ch, cl);
87
88 ah = (regs->regs[6]) >> 32;
89 al = (regs->regs[6]) & 0xffffffff;
90 bh = (regs->regs[7]) >> 32;
91 bl = (regs->regs[7]) & 0xffffffff;
92 ch = (regs->regs[8]) >> 32;
93 cl = (regs->regs[8]) & 0xffffffff;
94 printk("R6 : %08Lx%08Lx R7 : %08Lx%08Lx R8 : %08Lx%08Lx\n",
95 ah, al, bh, bl, ch, cl);
96
97 ah = (regs->regs[9]) >> 32;
98 al = (regs->regs[9]) & 0xffffffff;
99 bh = (regs->regs[10]) >> 32;
100 bl = (regs->regs[10]) & 0xffffffff;
101 ch = (regs->regs[11]) >> 32;
102 cl = (regs->regs[11]) & 0xffffffff;
103 printk("R9 : %08Lx%08Lx R10 : %08Lx%08Lx R11 : %08Lx%08Lx\n",
104 ah, al, bh, bl, ch, cl);
105
106 ah = (regs->regs[12]) >> 32;
107 al = (regs->regs[12]) & 0xffffffff;
108 bh = (regs->regs[13]) >> 32;
109 bl = (regs->regs[13]) & 0xffffffff;
110 ch = (regs->regs[14]) >> 32;
111 cl = (regs->regs[14]) & 0xffffffff;
112 printk("R12 : %08Lx%08Lx R13 : %08Lx%08Lx R14 : %08Lx%08Lx\n",
113 ah, al, bh, bl, ch, cl);
114
115 ah = (regs->regs[16]) >> 32;
116 al = (regs->regs[16]) & 0xffffffff;
117 bh = (regs->regs[17]) >> 32;
118 bl = (regs->regs[17]) & 0xffffffff;
119 ch = (regs->regs[19]) >> 32;
120 cl = (regs->regs[19]) & 0xffffffff;
121 printk("R16 : %08Lx%08Lx R17 : %08Lx%08Lx R19 : %08Lx%08Lx\n",
122 ah, al, bh, bl, ch, cl);
123
124 ah = (regs->regs[20]) >> 32;
125 al = (regs->regs[20]) & 0xffffffff;
126 bh = (regs->regs[21]) >> 32;
127 bl = (regs->regs[21]) & 0xffffffff;
128 ch = (regs->regs[22]) >> 32;
129 cl = (regs->regs[22]) & 0xffffffff;
130 printk("R20 : %08Lx%08Lx R21 : %08Lx%08Lx R22 : %08Lx%08Lx\n",
131 ah, al, bh, bl, ch, cl);
132
133 ah = (regs->regs[23]) >> 32;
134 al = (regs->regs[23]) & 0xffffffff;
135 bh = (regs->regs[24]) >> 32;
136 bl = (regs->regs[24]) & 0xffffffff;
137 ch = (regs->regs[25]) >> 32;
138 cl = (regs->regs[25]) & 0xffffffff;
139 printk("R23 : %08Lx%08Lx R24 : %08Lx%08Lx R25 : %08Lx%08Lx\n",
140 ah, al, bh, bl, ch, cl);
141
142 ah = (regs->regs[26]) >> 32;
143 al = (regs->regs[26]) & 0xffffffff;
144 bh = (regs->regs[27]) >> 32;
145 bl = (regs->regs[27]) & 0xffffffff;
146 ch = (regs->regs[28]) >> 32;
147 cl = (regs->regs[28]) & 0xffffffff;
148 printk("R26 : %08Lx%08Lx R27 : %08Lx%08Lx R28 : %08Lx%08Lx\n",
149 ah, al, bh, bl, ch, cl);
150
151 ah = (regs->regs[29]) >> 32;
152 al = (regs->regs[29]) & 0xffffffff;
153 bh = (regs->regs[30]) >> 32;
154 bl = (regs->regs[30]) & 0xffffffff;
155 ch = (regs->regs[31]) >> 32;
156 cl = (regs->regs[31]) & 0xffffffff;
157 printk("R29 : %08Lx%08Lx R30 : %08Lx%08Lx R31 : %08Lx%08Lx\n",
158 ah, al, bh, bl, ch, cl);
159
160 ah = (regs->regs[32]) >> 32;
161 al = (regs->regs[32]) & 0xffffffff;
162 bh = (regs->regs[33]) >> 32;
163 bl = (regs->regs[33]) & 0xffffffff;
164 ch = (regs->regs[34]) >> 32;
165 cl = (regs->regs[34]) & 0xffffffff;
166 printk("R32 : %08Lx%08Lx R33 : %08Lx%08Lx R34 : %08Lx%08Lx\n",
167 ah, al, bh, bl, ch, cl);
168
169 ah = (regs->regs[35]) >> 32;
170 al = (regs->regs[35]) & 0xffffffff;
171 bh = (regs->regs[36]) >> 32;
172 bl = (regs->regs[36]) & 0xffffffff;
173 ch = (regs->regs[37]) >> 32;
174 cl = (regs->regs[37]) & 0xffffffff;
175 printk("R35 : %08Lx%08Lx R36 : %08Lx%08Lx R37 : %08Lx%08Lx\n",
176 ah, al, bh, bl, ch, cl);
177
178 ah = (regs->regs[38]) >> 32;
179 al = (regs->regs[38]) & 0xffffffff;
180 bh = (regs->regs[39]) >> 32;
181 bl = (regs->regs[39]) & 0xffffffff;
182 ch = (regs->regs[40]) >> 32;
183 cl = (regs->regs[40]) & 0xffffffff;
184 printk("R38 : %08Lx%08Lx R39 : %08Lx%08Lx R40 : %08Lx%08Lx\n",
185 ah, al, bh, bl, ch, cl);
186
187 ah = (regs->regs[41]) >> 32;
188 al = (regs->regs[41]) & 0xffffffff;
189 bh = (regs->regs[42]) >> 32;
190 bl = (regs->regs[42]) & 0xffffffff;
191 ch = (regs->regs[43]) >> 32;
192 cl = (regs->regs[43]) & 0xffffffff;
193 printk("R41 : %08Lx%08Lx R42 : %08Lx%08Lx R43 : %08Lx%08Lx\n",
194 ah, al, bh, bl, ch, cl);
195
196 ah = (regs->regs[44]) >> 32;
197 al = (regs->regs[44]) & 0xffffffff;
198 bh = (regs->regs[45]) >> 32;
199 bl = (regs->regs[45]) & 0xffffffff;
200 ch = (regs->regs[46]) >> 32;
201 cl = (regs->regs[46]) & 0xffffffff;
202 printk("R44 : %08Lx%08Lx R45 : %08Lx%08Lx R46 : %08Lx%08Lx\n",
203 ah, al, bh, bl, ch, cl);
204
205 ah = (regs->regs[47]) >> 32;
206 al = (regs->regs[47]) & 0xffffffff;
207 bh = (regs->regs[48]) >> 32;
208 bl = (regs->regs[48]) & 0xffffffff;
209 ch = (regs->regs[49]) >> 32;
210 cl = (regs->regs[49]) & 0xffffffff;
211 printk("R47 : %08Lx%08Lx R48 : %08Lx%08Lx R49 : %08Lx%08Lx\n",
212 ah, al, bh, bl, ch, cl);
213
214 ah = (regs->regs[50]) >> 32;
215 al = (regs->regs[50]) & 0xffffffff;
216 bh = (regs->regs[51]) >> 32;
217 bl = (regs->regs[51]) & 0xffffffff;
218 ch = (regs->regs[52]) >> 32;
219 cl = (regs->regs[52]) & 0xffffffff;
220 printk("R50 : %08Lx%08Lx R51 : %08Lx%08Lx R52 : %08Lx%08Lx\n",
221 ah, al, bh, bl, ch, cl);
222
223 ah = (regs->regs[53]) >> 32;
224 al = (regs->regs[53]) & 0xffffffff;
225 bh = (regs->regs[54]) >> 32;
226 bl = (regs->regs[54]) & 0xffffffff;
227 ch = (regs->regs[55]) >> 32;
228 cl = (regs->regs[55]) & 0xffffffff;
229 printk("R53 : %08Lx%08Lx R54 : %08Lx%08Lx R55 : %08Lx%08Lx\n",
230 ah, al, bh, bl, ch, cl);
231
232 ah = (regs->regs[56]) >> 32;
233 al = (regs->regs[56]) & 0xffffffff;
234 bh = (regs->regs[57]) >> 32;
235 bl = (regs->regs[57]) & 0xffffffff;
236 ch = (regs->regs[58]) >> 32;
237 cl = (regs->regs[58]) & 0xffffffff;
238 printk("R56 : %08Lx%08Lx R57 : %08Lx%08Lx R58 : %08Lx%08Lx\n",
239 ah, al, bh, bl, ch, cl);
240
241 ah = (regs->regs[59]) >> 32;
242 al = (regs->regs[59]) & 0xffffffff;
243 bh = (regs->regs[60]) >> 32;
244 bl = (regs->regs[60]) & 0xffffffff;
245 ch = (regs->regs[61]) >> 32;
246 cl = (regs->regs[61]) & 0xffffffff;
247 printk("R59 : %08Lx%08Lx R60 : %08Lx%08Lx R61 : %08Lx%08Lx\n",
248 ah, al, bh, bl, ch, cl);
249
250 ah = (regs->regs[62]) >> 32;
251 al = (regs->regs[62]) & 0xffffffff;
252 bh = (regs->tregs[0]) >> 32;
253 bl = (regs->tregs[0]) & 0xffffffff;
254 ch = (regs->tregs[1]) >> 32;
255 cl = (regs->tregs[1]) & 0xffffffff;
256 printk("R62 : %08Lx%08Lx T0 : %08Lx%08Lx T1 : %08Lx%08Lx\n",
257 ah, al, bh, bl, ch, cl);
258
259 ah = (regs->tregs[2]) >> 32;
260 al = (regs->tregs[2]) & 0xffffffff;
261 bh = (regs->tregs[3]) >> 32;
262 bl = (regs->tregs[3]) & 0xffffffff;
263 ch = (regs->tregs[4]) >> 32;
264 cl = (regs->tregs[4]) & 0xffffffff;
265 printk("T2 : %08Lx%08Lx T3 : %08Lx%08Lx T4 : %08Lx%08Lx\n",
266 ah, al, bh, bl, ch, cl);
267
268 ah = (regs->tregs[5]) >> 32;
269 al = (regs->tregs[5]) & 0xffffffff;
270 bh = (regs->tregs[6]) >> 32;
271 bl = (regs->tregs[6]) & 0xffffffff;
272 ch = (regs->tregs[7]) >> 32;
273 cl = (regs->tregs[7]) & 0xffffffff;
274 printk("T5 : %08Lx%08Lx T6 : %08Lx%08Lx T7 : %08Lx%08Lx\n",
275 ah, al, bh, bl, ch, cl);
276
277 /*
278 * If we're in kernel mode, dump the stack too..
279 */
280 if (!user_mode(regs)) {
281 void show_stack(struct task_struct *tsk, unsigned long *sp);
282 unsigned long sp = regs->regs[15] & 0xffffffff;
283 struct task_struct *tsk = get_current();
284
285 tsk->thread.kregs = regs;
286
287 show_stack(tsk, (unsigned long *)sp);
288 }
289 }
290
291 /*
292 * Free current thread data structures etc..
293 */
exit_thread(struct task_struct * tsk)294 void exit_thread(struct task_struct *tsk)
295 {
296 /*
297 * See arch/sparc/kernel/process.c for the precedent for doing
298 * this -- RPC.
299 *
300 * The SH-5 FPU save/restore approach relies on
301 * last_task_used_math pointing to a live task_struct. When
302 * another task tries to use the FPU for the 1st time, the FPUDIS
303 * trap handling (see arch/sh/kernel/cpu/sh5/fpu.c) will save the
304 * existing FPU state to the FP regs field within
305 * last_task_used_math before re-loading the new task's FPU state
306 * (or initialising it if the FPU has been used before). So if
307 * last_task_used_math is stale, and its page has already been
308 * re-allocated for another use, the consequences are rather
309 * grim. Unless we null it here, there is no other path through
310 * which it would get safely nulled.
311 */
312 #ifdef CONFIG_SH_FPU
313 if (last_task_used_math == tsk)
314 last_task_used_math = NULL;
315 #endif
316 }
317
flush_thread(void)318 void flush_thread(void)
319 {
320
321 /* Called by fs/exec.c (setup_new_exec) to remove traces of a
322 * previously running executable. */
323 #ifdef CONFIG_SH_FPU
324 if (last_task_used_math == current) {
325 last_task_used_math = NULL;
326 }
327 /* Force FPU state to be reinitialised after exec */
328 clear_used_math();
329 #endif
330
331 /* if we are a kernel thread, about to change to user thread,
332 * update kreg
333 */
334 if(current->thread.kregs==&fake_swapper_regs) {
335 current->thread.kregs =
336 ((struct pt_regs *)(THREAD_SIZE + (unsigned long) current) - 1);
337 current->thread.uregs = current->thread.kregs;
338 }
339 }
340
release_thread(struct task_struct * dead_task)341 void release_thread(struct task_struct *dead_task)
342 {
343 /* do nothing */
344 }
345
346 /* Fill in the fpu structure for a core dump.. */
dump_fpu(struct pt_regs * regs,elf_fpregset_t * fpu)347 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
348 {
349 #ifdef CONFIG_SH_FPU
350 int fpvalid;
351 struct task_struct *tsk = current;
352
353 fpvalid = !!tsk_used_math(tsk);
354 if (fpvalid) {
355 if (current == last_task_used_math) {
356 enable_fpu();
357 save_fpu(tsk);
358 disable_fpu();
359 last_task_used_math = 0;
360 regs->sr |= SR_FD;
361 }
362
363 memcpy(fpu, &tsk->thread.xstate->hardfpu, sizeof(*fpu));
364 }
365
366 return fpvalid;
367 #else
368 return 0; /* Task didn't use the fpu at all. */
369 #endif
370 }
371 EXPORT_SYMBOL(dump_fpu);
372
373 asmlinkage void ret_from_fork(void);
374 asmlinkage void ret_from_kernel_thread(void);
375
copy_thread(unsigned long clone_flags,unsigned long usp,unsigned long arg,struct task_struct * p)376 int copy_thread(unsigned long clone_flags, unsigned long usp,
377 unsigned long arg, struct task_struct *p)
378 {
379 struct pt_regs *childregs;
380
381 #ifdef CONFIG_SH_FPU
382 /* can't happen for a kernel thread */
383 if (last_task_used_math == current) {
384 enable_fpu();
385 save_fpu(current);
386 disable_fpu();
387 last_task_used_math = NULL;
388 current_pt_regs()->sr |= SR_FD;
389 }
390 #endif
391 /* Copy from sh version */
392 childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1;
393 p->thread.sp = (unsigned long) childregs;
394
395 if (unlikely(p->flags & PF_KTHREAD)) {
396 memset(childregs, 0, sizeof(struct pt_regs));
397 childregs->regs[2] = (unsigned long)arg;
398 childregs->regs[3] = (unsigned long)usp;
399 childregs->sr = (1 << 30); /* not user_mode */
400 childregs->sr |= SR_FD; /* Invalidate FPU flag */
401 p->thread.pc = (unsigned long) ret_from_kernel_thread;
402 return 0;
403 }
404 *childregs = *current_pt_regs();
405
406 /*
407 * Sign extend the edited stack.
408 * Note that thread.pc and thread.pc will stay
409 * 32-bit wide and context switch must take care
410 * of NEFF sign extension.
411 */
412 if (usp)
413 childregs->regs[15] = neff_sign_extend(usp);
414 p->thread.uregs = childregs;
415
416 childregs->regs[9] = 0; /* Set return value for child */
417 childregs->sr |= SR_FD; /* Invalidate FPU flag */
418
419 p->thread.pc = (unsigned long) ret_from_fork;
420
421 return 0;
422 }
423
424 #ifdef CONFIG_FRAME_POINTER
in_sh64_switch_to(unsigned long pc)425 static int in_sh64_switch_to(unsigned long pc)
426 {
427 extern char __sh64_switch_to_end;
428 /* For a sleeping task, the PC is somewhere in the middle of the function,
429 so we don't have to worry about masking the LSB off */
430 return (pc >= (unsigned long) sh64_switch_to) &&
431 (pc < (unsigned long) &__sh64_switch_to_end);
432 }
433 #endif
434
get_wchan(struct task_struct * p)435 unsigned long get_wchan(struct task_struct *p)
436 {
437 unsigned long pc;
438
439 if (!p || p == current || p->state == TASK_RUNNING)
440 return 0;
441
442 /*
443 * The same comment as on the Alpha applies here, too ...
444 */
445 pc = thread_saved_pc(p);
446
447 #ifdef CONFIG_FRAME_POINTER
448 if (in_sh64_switch_to(pc)) {
449 unsigned long schedule_fp;
450 unsigned long sh64_switch_to_fp;
451 unsigned long schedule_caller_pc;
452
453 sh64_switch_to_fp = (long) p->thread.sp;
454 /* r14 is saved at offset 4 in the sh64_switch_to frame */
455 schedule_fp = *(unsigned long *) (long)(sh64_switch_to_fp + 4);
456
457 /* and the caller of 'schedule' is (currently!) saved at offset 24
458 in the frame of schedule (from disasm) */
459 schedule_caller_pc = *(unsigned long *) (long)(schedule_fp + 24);
460 return schedule_caller_pc;
461 }
462 #endif
463 return pc;
464 }
465
