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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * arch/sh/kernel/process_64.c
4 *
5 * This file handles the architecture-dependent parts of process handling..
6 *
7 * Copyright (C) 2000, 2001 Paolo Alberelli
8 * Copyright (C) 2003 - 2007 Paul Mundt
9 * Copyright (C) 2003, 2004 Richard Curnow
10 *
11 * Started from SH3/4 version:
12 * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
13 *
14 * In turn started from i386 version:
15 * Copyright (C) 1995 Linus Torvalds
16 */
17#include <linux/mm.h>
18#include <linux/fs.h>
19#include <linux/ptrace.h>
20#include <linux/reboot.h>
21#include <linux/slab.h>
22#include <linux/init.h>
23#include <linux/module.h>
24#include <linux/io.h>
25#include <linux/sched/debug.h>
26#include <linux/sched/task.h>
27#include <linux/sched/task_stack.h>
28#include <asm/syscalls.h>
29#include <linux/uaccess.h>
30#include <asm/pgtable.h>
31#include <asm/mmu_context.h>
32#include <asm/fpu.h>
33#include <asm/switch_to.h>
34
35struct task_struct *last_task_used_math = NULL;
36struct pt_regs fake_swapper_regs = { 0, };
37
38void show_regs(struct pt_regs *regs)
39{
40 unsigned long long ah, al, bh, bl, ch, cl;
41
42 printk("\n");
43 show_regs_print_info(KERN_DEFAULT);
44
45 ah = (regs->pc) >> 32;
46 al = (regs->pc) & 0xffffffff;
47 bh = (regs->regs[18]) >> 32;
48 bl = (regs->regs[18]) & 0xffffffff;
49 ch = (regs->regs[15]) >> 32;
50 cl = (regs->regs[15]) & 0xffffffff;
51 printk("PC : %08Lx%08Lx LINK: %08Lx%08Lx SP : %08Lx%08Lx\n",
52 ah, al, bh, bl, ch, cl);
53
54 ah = (regs->sr) >> 32;
55 al = (regs->sr) & 0xffffffff;
56 asm volatile ("getcon " __TEA ", %0" : "=r" (bh));
57 asm volatile ("getcon " __TEA ", %0" : "=r" (bl));
58 bh = (bh) >> 32;
59 bl = (bl) & 0xffffffff;
60 asm volatile ("getcon " __KCR0 ", %0" : "=r" (ch));
61 asm volatile ("getcon " __KCR0 ", %0" : "=r" (cl));
62 ch = (ch) >> 32;
63 cl = (cl) & 0xffffffff;
64 printk("SR : %08Lx%08Lx TEA : %08Lx%08Lx KCR0: %08Lx%08Lx\n",
65 ah, al, bh, bl, ch, cl);
66
67 ah = (regs->regs[0]) >> 32;
68 al = (regs->regs[0]) & 0xffffffff;
69 bh = (regs->regs[1]) >> 32;
70 bl = (regs->regs[1]) & 0xffffffff;
71 ch = (regs->regs[2]) >> 32;
72 cl = (regs->regs[2]) & 0xffffffff;
73 printk("R0 : %08Lx%08Lx R1 : %08Lx%08Lx R2 : %08Lx%08Lx\n",
74 ah, al, bh, bl, ch, cl);
75
76 ah = (regs->regs[3]) >> 32;
77 al = (regs->regs[3]) & 0xffffffff;
78 bh = (regs->regs[4]) >> 32;
79 bl = (regs->regs[4]) & 0xffffffff;
80 ch = (regs->regs[5]) >> 32;
81 cl = (regs->regs[5]) & 0xffffffff;
82 printk("R3 : %08Lx%08Lx R4 : %08Lx%08Lx R5 : %08Lx%08Lx\n",
83 ah, al, bh, bl, ch, cl);
84
85 ah = (regs->regs[6]) >> 32;
86 al = (regs->regs[6]) & 0xffffffff;
87 bh = (regs->regs[7]) >> 32;
88 bl = (regs->regs[7]) & 0xffffffff;
89 ch = (regs->regs[8]) >> 32;
90 cl = (regs->regs[8]) & 0xffffffff;
91 printk("R6 : %08Lx%08Lx R7 : %08Lx%08Lx R8 : %08Lx%08Lx\n",
92 ah, al, bh, bl, ch, cl);
93
94 ah = (regs->regs[9]) >> 32;
95 al = (regs->regs[9]) & 0xffffffff;
96 bh = (regs->regs[10]) >> 32;
97 bl = (regs->regs[10]) & 0xffffffff;
98 ch = (regs->regs[11]) >> 32;
99 cl = (regs->regs[11]) & 0xffffffff;
100 printk("R9 : %08Lx%08Lx R10 : %08Lx%08Lx R11 : %08Lx%08Lx\n",
101 ah, al, bh, bl, ch, cl);
102
103 ah = (regs->regs[12]) >> 32;
104 al = (regs->regs[12]) & 0xffffffff;
105 bh = (regs->regs[13]) >> 32;
106 bl = (regs->regs[13]) & 0xffffffff;
107 ch = (regs->regs[14]) >> 32;
108 cl = (regs->regs[14]) & 0xffffffff;
109 printk("R12 : %08Lx%08Lx R13 : %08Lx%08Lx R14 : %08Lx%08Lx\n",
110 ah, al, bh, bl, ch, cl);
111
112 ah = (regs->regs[16]) >> 32;
113 al = (regs->regs[16]) & 0xffffffff;
114 bh = (regs->regs[17]) >> 32;
115 bl = (regs->regs[17]) & 0xffffffff;
116 ch = (regs->regs[19]) >> 32;
117 cl = (regs->regs[19]) & 0xffffffff;
118 printk("R16 : %08Lx%08Lx R17 : %08Lx%08Lx R19 : %08Lx%08Lx\n",
119 ah, al, bh, bl, ch, cl);
120
121 ah = (regs->regs[20]) >> 32;
122 al = (regs->regs[20]) & 0xffffffff;
123 bh = (regs->regs[21]) >> 32;
124 bl = (regs->regs[21]) & 0xffffffff;
125 ch = (regs->regs[22]) >> 32;
126 cl = (regs->regs[22]) & 0xffffffff;
127 printk("R20 : %08Lx%08Lx R21 : %08Lx%08Lx R22 : %08Lx%08Lx\n",
128 ah, al, bh, bl, ch, cl);
129
130 ah = (regs->regs[23]) >> 32;
131 al = (regs->regs[23]) & 0xffffffff;
132 bh = (regs->regs[24]) >> 32;
133 bl = (regs->regs[24]) & 0xffffffff;
134 ch = (regs->regs[25]) >> 32;
135 cl = (regs->regs[25]) & 0xffffffff;
136 printk("R23 : %08Lx%08Lx R24 : %08Lx%08Lx R25 : %08Lx%08Lx\n",
137 ah, al, bh, bl, ch, cl);
138
139 ah = (regs->regs[26]) >> 32;
140 al = (regs->regs[26]) & 0xffffffff;
141 bh = (regs->regs[27]) >> 32;
142 bl = (regs->regs[27]) & 0xffffffff;
143 ch = (regs->regs[28]) >> 32;
144 cl = (regs->regs[28]) & 0xffffffff;
145 printk("R26 : %08Lx%08Lx R27 : %08Lx%08Lx R28 : %08Lx%08Lx\n",
146 ah, al, bh, bl, ch, cl);
147
148 ah = (regs->regs[29]) >> 32;
149 al = (regs->regs[29]) & 0xffffffff;
150 bh = (regs->regs[30]) >> 32;
151 bl = (regs->regs[30]) & 0xffffffff;
152 ch = (regs->regs[31]) >> 32;
153 cl = (regs->regs[31]) & 0xffffffff;
154 printk("R29 : %08Lx%08Lx R30 : %08Lx%08Lx R31 : %08Lx%08Lx\n",
155 ah, al, bh, bl, ch, cl);
156
157 ah = (regs->regs[32]) >> 32;
158 al = (regs->regs[32]) & 0xffffffff;
159 bh = (regs->regs[33]) >> 32;
160 bl = (regs->regs[33]) & 0xffffffff;
161 ch = (regs->regs[34]) >> 32;
162 cl = (regs->regs[34]) & 0xffffffff;
163 printk("R32 : %08Lx%08Lx R33 : %08Lx%08Lx R34 : %08Lx%08Lx\n",
164 ah, al, bh, bl, ch, cl);
165
166 ah = (regs->regs[35]) >> 32;
167 al = (regs->regs[35]) & 0xffffffff;
168 bh = (regs->regs[36]) >> 32;
169 bl = (regs->regs[36]) & 0xffffffff;
170 ch = (regs->regs[37]) >> 32;
171 cl = (regs->regs[37]) & 0xffffffff;
172 printk("R35 : %08Lx%08Lx R36 : %08Lx%08Lx R37 : %08Lx%08Lx\n",
173 ah, al, bh, bl, ch, cl);
174
175 ah = (regs->regs[38]) >> 32;
176 al = (regs->regs[38]) & 0xffffffff;
177 bh = (regs->regs[39]) >> 32;
178 bl = (regs->regs[39]) & 0xffffffff;
179 ch = (regs->regs[40]) >> 32;
180 cl = (regs->regs[40]) & 0xffffffff;
181 printk("R38 : %08Lx%08Lx R39 : %08Lx%08Lx R40 : %08Lx%08Lx\n",
182 ah, al, bh, bl, ch, cl);
183
184 ah = (regs->regs[41]) >> 32;
185 al = (regs->regs[41]) & 0xffffffff;
186 bh = (regs->regs[42]) >> 32;
187 bl = (regs->regs[42]) & 0xffffffff;
188 ch = (regs->regs[43]) >> 32;
189 cl = (regs->regs[43]) & 0xffffffff;
190 printk("R41 : %08Lx%08Lx R42 : %08Lx%08Lx R43 : %08Lx%08Lx\n",
191 ah, al, bh, bl, ch, cl);
192
193 ah = (regs->regs[44]) >> 32;
194 al = (regs->regs[44]) & 0xffffffff;
195 bh = (regs->regs[45]) >> 32;
196 bl = (regs->regs[45]) & 0xffffffff;
197 ch = (regs->regs[46]) >> 32;
198 cl = (regs->regs[46]) & 0xffffffff;
199 printk("R44 : %08Lx%08Lx R45 : %08Lx%08Lx R46 : %08Lx%08Lx\n",
200 ah, al, bh, bl, ch, cl);
201
202 ah = (regs->regs[47]) >> 32;
203 al = (regs->regs[47]) & 0xffffffff;
204 bh = (regs->regs[48]) >> 32;
205 bl = (regs->regs[48]) & 0xffffffff;
206 ch = (regs->regs[49]) >> 32;
207 cl = (regs->regs[49]) & 0xffffffff;
208 printk("R47 : %08Lx%08Lx R48 : %08Lx%08Lx R49 : %08Lx%08Lx\n",
209 ah, al, bh, bl, ch, cl);
210
211 ah = (regs->regs[50]) >> 32;
212 al = (regs->regs[50]) & 0xffffffff;
213 bh = (regs->regs[51]) >> 32;
214 bl = (regs->regs[51]) & 0xffffffff;
215 ch = (regs->regs[52]) >> 32;
216 cl = (regs->regs[52]) & 0xffffffff;
217 printk("R50 : %08Lx%08Lx R51 : %08Lx%08Lx R52 : %08Lx%08Lx\n",
218 ah, al, bh, bl, ch, cl);
219
220 ah = (regs->regs[53]) >> 32;
221 al = (regs->regs[53]) & 0xffffffff;
222 bh = (regs->regs[54]) >> 32;
223 bl = (regs->regs[54]) & 0xffffffff;
224 ch = (regs->regs[55]) >> 32;
225 cl = (regs->regs[55]) & 0xffffffff;
226 printk("R53 : %08Lx%08Lx R54 : %08Lx%08Lx R55 : %08Lx%08Lx\n",
227 ah, al, bh, bl, ch, cl);
228
229 ah = (regs->regs[56]) >> 32;
230 al = (regs->regs[56]) & 0xffffffff;
231 bh = (regs->regs[57]) >> 32;
232 bl = (regs->regs[57]) & 0xffffffff;
233 ch = (regs->regs[58]) >> 32;
234 cl = (regs->regs[58]) & 0xffffffff;
235 printk("R56 : %08Lx%08Lx R57 : %08Lx%08Lx R58 : %08Lx%08Lx\n",
236 ah, al, bh, bl, ch, cl);
237
238 ah = (regs->regs[59]) >> 32;
239 al = (regs->regs[59]) & 0xffffffff;
240 bh = (regs->regs[60]) >> 32;
241 bl = (regs->regs[60]) & 0xffffffff;
242 ch = (regs->regs[61]) >> 32;
243 cl = (regs->regs[61]) & 0xffffffff;
244 printk("R59 : %08Lx%08Lx R60 : %08Lx%08Lx R61 : %08Lx%08Lx\n",
245 ah, al, bh, bl, ch, cl);
246
247 ah = (regs->regs[62]) >> 32;
248 al = (regs->regs[62]) & 0xffffffff;
249 bh = (regs->tregs[0]) >> 32;
250 bl = (regs->tregs[0]) & 0xffffffff;
251 ch = (regs->tregs[1]) >> 32;
252 cl = (regs->tregs[1]) & 0xffffffff;
253 printk("R62 : %08Lx%08Lx T0 : %08Lx%08Lx T1 : %08Lx%08Lx\n",
254 ah, al, bh, bl, ch, cl);
255
256 ah = (regs->tregs[2]) >> 32;
257 al = (regs->tregs[2]) & 0xffffffff;
258 bh = (regs->tregs[3]) >> 32;
259 bl = (regs->tregs[3]) & 0xffffffff;
260 ch = (regs->tregs[4]) >> 32;
261 cl = (regs->tregs[4]) & 0xffffffff;
262 printk("T2 : %08Lx%08Lx T3 : %08Lx%08Lx T4 : %08Lx%08Lx\n",
263 ah, al, bh, bl, ch, cl);
264
265 ah = (regs->tregs[5]) >> 32;
266 al = (regs->tregs[5]) & 0xffffffff;
267 bh = (regs->tregs[6]) >> 32;
268 bl = (regs->tregs[6]) & 0xffffffff;
269 ch = (regs->tregs[7]) >> 32;
270 cl = (regs->tregs[7]) & 0xffffffff;
271 printk("T5 : %08Lx%08Lx T6 : %08Lx%08Lx T7 : %08Lx%08Lx\n",
272 ah, al, bh, bl, ch, cl);
273
274 /*
275 * If we're in kernel mode, dump the stack too..
276 */
277 if (!user_mode(regs)) {
278 void show_stack(struct task_struct *tsk, unsigned long *sp);
279 unsigned long sp = regs->regs[15] & 0xffffffff;
280 struct task_struct *tsk = get_current();
281
282 tsk->thread.kregs = regs;
283
284 show_stack(tsk, (unsigned long *)sp);
285 }
286}
287
288/*
289 * Free current thread data structures etc..
290 */
291void exit_thread(struct task_struct *tsk)
292{
293 /*
294 * See arch/sparc/kernel/process.c for the precedent for doing
295 * this -- RPC.
296 *
297 * The SH-5 FPU save/restore approach relies on
298 * last_task_used_math pointing to a live task_struct. When
299 * another task tries to use the FPU for the 1st time, the FPUDIS
300 * trap handling (see arch/sh/kernel/cpu/sh5/fpu.c) will save the
301 * existing FPU state to the FP regs field within
302 * last_task_used_math before re-loading the new task's FPU state
303 * (or initialising it if the FPU has been used before). So if
304 * last_task_used_math is stale, and its page has already been
305 * re-allocated for another use, the consequences are rather
306 * grim. Unless we null it here, there is no other path through
307 * which it would get safely nulled.
308 */
309#ifdef CONFIG_SH_FPU
310 if (last_task_used_math == tsk)
311 last_task_used_math = NULL;
312#endif
313}
314
315void flush_thread(void)
316{
317
318 /* Called by fs/exec.c (setup_new_exec) to remove traces of a
319 * previously running executable. */
320#ifdef CONFIG_SH_FPU
321 if (last_task_used_math == current) {
322 last_task_used_math = NULL;
323 }
324 /* Force FPU state to be reinitialised after exec */
325 clear_used_math();
326#endif
327
328 /* if we are a kernel thread, about to change to user thread,
329 * update kreg
330 */
331 if(current->thread.kregs==&fake_swapper_regs) {
332 current->thread.kregs =
333 ((struct pt_regs *)(THREAD_SIZE + (unsigned long) current) - 1);
334 current->thread.uregs = current->thread.kregs;
335 }
336}
337
338void release_thread(struct task_struct *dead_task)
339{
340 /* do nothing */
341}
342
343/* Fill in the fpu structure for a core dump.. */
344int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
345{
346#ifdef CONFIG_SH_FPU
347 int fpvalid;
348 struct task_struct *tsk = current;
349
350 fpvalid = !!tsk_used_math(tsk);
351 if (fpvalid) {
352 if (current == last_task_used_math) {
353 enable_fpu();
354 save_fpu(tsk);
355 disable_fpu();
356 last_task_used_math = 0;
357 regs->sr |= SR_FD;
358 }
359
360 memcpy(fpu, &tsk->thread.xstate->hardfpu, sizeof(*fpu));
361 }
362
363 return fpvalid;
364#else
365 return 0; /* Task didn't use the fpu at all. */
366#endif
367}
368EXPORT_SYMBOL(dump_fpu);
369
370asmlinkage void ret_from_fork(void);
371asmlinkage void ret_from_kernel_thread(void);
372
373int copy_thread(unsigned long clone_flags, unsigned long usp,
374 unsigned long arg, struct task_struct *p)
375{
376 struct pt_regs *childregs;
377
378#ifdef CONFIG_SH_FPU
379 /* can't happen for a kernel thread */
380 if (last_task_used_math == current) {
381 enable_fpu();
382 save_fpu(current);
383 disable_fpu();
384 last_task_used_math = NULL;
385 current_pt_regs()->sr |= SR_FD;
386 }
387#endif
388 /* Copy from sh version */
389 childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1;
390 p->thread.sp = (unsigned long) childregs;
391
392 if (unlikely(p->flags & PF_KTHREAD)) {
393 memset(childregs, 0, sizeof(struct pt_regs));
394 childregs->regs[2] = (unsigned long)arg;
395 childregs->regs[3] = (unsigned long)usp;
396 childregs->sr = (1 << 30); /* not user_mode */
397 childregs->sr |= SR_FD; /* Invalidate FPU flag */
398 p->thread.pc = (unsigned long) ret_from_kernel_thread;
399 return 0;
400 }
401 *childregs = *current_pt_regs();
402
403 /*
404 * Sign extend the edited stack.
405 * Note that thread.pc and thread.pc will stay
406 * 32-bit wide and context switch must take care
407 * of NEFF sign extension.
408 */
409 if (usp)
410 childregs->regs[15] = neff_sign_extend(usp);
411 p->thread.uregs = childregs;
412
413 childregs->regs[9] = 0; /* Set return value for child */
414 childregs->sr |= SR_FD; /* Invalidate FPU flag */
415
416 p->thread.pc = (unsigned long) ret_from_fork;
417
418 return 0;
419}
420
421#ifdef CONFIG_FRAME_POINTER
422static int in_sh64_switch_to(unsigned long pc)
423{
424 extern char __sh64_switch_to_end;
425 /* For a sleeping task, the PC is somewhere in the middle of the function,
426 so we don't have to worry about masking the LSB off */
427 return (pc >= (unsigned long) sh64_switch_to) &&
428 (pc < (unsigned long) &__sh64_switch_to_end);
429}
430#endif
431
432unsigned long get_wchan(struct task_struct *p)
433{
434 unsigned long pc;
435
436 if (!p || p == current || p->state == TASK_RUNNING)
437 return 0;
438
439 /*
440 * The same comment as on the Alpha applies here, too ...
441 */
442 pc = thread_saved_pc(p);
443
444#ifdef CONFIG_FRAME_POINTER
445 if (in_sh64_switch_to(pc)) {
446 unsigned long schedule_fp;
447 unsigned long sh64_switch_to_fp;
448 unsigned long schedule_caller_pc;
449
450 sh64_switch_to_fp = (long) p->thread.sp;
451 /* r14 is saved at offset 4 in the sh64_switch_to frame */
452 schedule_fp = *(unsigned long *) (long)(sh64_switch_to_fp + 4);
453
454 /* and the caller of 'schedule' is (currently!) saved at offset 24
455 in the frame of schedule (from disasm) */
456 schedule_caller_pc = *(unsigned long *) (long)(schedule_fp + 24);
457 return schedule_caller_pc;
458 }
459#endif
460 return pc;
461}