1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 */
5
6#include <linux/ptrace.h>
7#include <linux/sched/task_stack.h>
8#include <linux/regset.h>
9#include <linux/unistd.h>
10#include <linux/elf.h>
11
12#define CREATE_TRACE_POINTS
13#include <trace/events/syscalls.h>
14
15struct pt_regs_offset {
16	const char *name;
17	int offset;
18};
19
20#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
21#define REG_OFFSET_END {.name = NULL, .offset = 0}
22
23#ifdef CONFIG_ISA_ARCOMPACT
24static const struct pt_regs_offset regoffset_table[] = {
25	REG_OFFSET_NAME(bta),
26	REG_OFFSET_NAME(lp_start),
27	REG_OFFSET_NAME(lp_end),
28	REG_OFFSET_NAME(lp_count),
29	REG_OFFSET_NAME(status32),
30	REG_OFFSET_NAME(ret),
31	REG_OFFSET_NAME(blink),
32	REG_OFFSET_NAME(fp),
33	REG_OFFSET_NAME(r26),
34	REG_OFFSET_NAME(r12),
35	REG_OFFSET_NAME(r11),
36	REG_OFFSET_NAME(r10),
37	REG_OFFSET_NAME(r9),
38	REG_OFFSET_NAME(r8),
39	REG_OFFSET_NAME(r7),
40	REG_OFFSET_NAME(r6),
41	REG_OFFSET_NAME(r5),
42	REG_OFFSET_NAME(r4),
43	REG_OFFSET_NAME(r3),
44	REG_OFFSET_NAME(r2),
45	REG_OFFSET_NAME(r1),
46	REG_OFFSET_NAME(r0),
47	REG_OFFSET_NAME(sp),
48	REG_OFFSET_NAME(orig_r0),
49	REG_OFFSET_NAME(ecr),
50	REG_OFFSET_END,
51};
52
53#else
54
55static const struct pt_regs_offset regoffset_table[] = {
56	REG_OFFSET_NAME(orig_r0),
57	REG_OFFSET_NAME(ecr),
58	REG_OFFSET_NAME(bta),
59	REG_OFFSET_NAME(r26),
60	REG_OFFSET_NAME(fp),
61	REG_OFFSET_NAME(sp),
62	REG_OFFSET_NAME(r12),
63	REG_OFFSET_NAME(r30),
64#ifdef CONFIG_ARC_HAS_ACCL_REGS
65	REG_OFFSET_NAME(r58),
66	REG_OFFSET_NAME(r59),
67#endif
68#ifdef CONFIG_ARC_DSP_SAVE_RESTORE_REGS
69	REG_OFFSET_NAME(DSP_CTRL),
70#endif
71	REG_OFFSET_NAME(r0),
72	REG_OFFSET_NAME(r1),
73	REG_OFFSET_NAME(r2),
74	REG_OFFSET_NAME(r3),
75	REG_OFFSET_NAME(r4),
76	REG_OFFSET_NAME(r5),
77	REG_OFFSET_NAME(r6),
78	REG_OFFSET_NAME(r7),
79	REG_OFFSET_NAME(r8),
80	REG_OFFSET_NAME(r9),
81	REG_OFFSET_NAME(r10),
82	REG_OFFSET_NAME(r11),
83	REG_OFFSET_NAME(blink),
84	REG_OFFSET_NAME(lp_end),
85	REG_OFFSET_NAME(lp_start),
86	REG_OFFSET_NAME(lp_count),
87	REG_OFFSET_NAME(ei),
88	REG_OFFSET_NAME(ldi),
89	REG_OFFSET_NAME(jli),
90	REG_OFFSET_NAME(ret),
91	REG_OFFSET_NAME(status32),
92	REG_OFFSET_END,
93};
94#endif
95
96static struct callee_regs *task_callee_regs(struct task_struct *tsk)
97{
98	struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg;
99	return tmp;
100}
101
102static int genregs_get(struct task_struct *target,
103		       const struct user_regset *regset,
104		       struct membuf to)
105{
106	const struct pt_regs *ptregs = task_pt_regs(target);
107	const struct callee_regs *cregs = task_callee_regs(target);
108	unsigned int stop_pc_val;
109
110	membuf_zero(&to, 4);	// pad
111	membuf_store(&to, ptregs->bta);
112	membuf_store(&to, ptregs->lp_start);
113	membuf_store(&to, ptregs->lp_end);
114	membuf_store(&to, ptregs->lp_count);
115	membuf_store(&to, ptregs->status32);
116	membuf_store(&to, ptregs->ret);
117	membuf_store(&to, ptregs->blink);
118	membuf_store(&to, ptregs->fp);
119	membuf_store(&to, ptregs->r26);	// gp
120	membuf_store(&to, ptregs->r12);
121	membuf_store(&to, ptregs->r11);
122	membuf_store(&to, ptregs->r10);
123	membuf_store(&to, ptregs->r9);
124	membuf_store(&to, ptregs->r8);
125	membuf_store(&to, ptregs->r7);
126	membuf_store(&to, ptregs->r6);
127	membuf_store(&to, ptregs->r5);
128	membuf_store(&to, ptregs->r4);
129	membuf_store(&to, ptregs->r3);
130	membuf_store(&to, ptregs->r2);
131	membuf_store(&to, ptregs->r1);
132	membuf_store(&to, ptregs->r0);
133	membuf_store(&to, ptregs->sp);
134	membuf_zero(&to, 4);	// pad2
135	membuf_store(&to, cregs->r25);
136	membuf_store(&to, cregs->r24);
137	membuf_store(&to, cregs->r23);
138	membuf_store(&to, cregs->r22);
139	membuf_store(&to, cregs->r21);
140	membuf_store(&to, cregs->r20);
141	membuf_store(&to, cregs->r19);
142	membuf_store(&to, cregs->r18);
143	membuf_store(&to, cregs->r17);
144	membuf_store(&to, cregs->r16);
145	membuf_store(&to, cregs->r15);
146	membuf_store(&to, cregs->r14);
147	membuf_store(&to, cregs->r13);
148	membuf_store(&to, target->thread.fault_address); // efa
149
150	if (in_brkpt_trap(ptregs)) {
151		stop_pc_val = target->thread.fault_address;
152		pr_debug("\t\tstop_pc (brk-pt)\n");
153	} else {
154		stop_pc_val = ptregs->ret;
155		pr_debug("\t\tstop_pc (others)\n");
156	}
157
158	return membuf_store(&to, stop_pc_val); // stop_pc
159}
160
161static int genregs_set(struct task_struct *target,
162		       const struct user_regset *regset,
163		       unsigned int pos, unsigned int count,
164		       const void *kbuf, const void __user *ubuf)
165{
166	const struct pt_regs *ptregs = task_pt_regs(target);
167	const struct callee_regs *cregs = task_callee_regs(target);
168	int ret = 0;
169
170#define REG_IN_CHUNK(FIRST, NEXT, PTR)	\
171	if (!ret)			\
172		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
173			(void *)(PTR), \
174			offsetof(struct user_regs_struct, FIRST), \
175			offsetof(struct user_regs_struct, NEXT));
176
177#define REG_IN_ONE(LOC, PTR)		\
178	if (!ret)			\
179		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
180			(void *)(PTR), \
181			offsetof(struct user_regs_struct, LOC), \
182			offsetof(struct user_regs_struct, LOC) + 4);
183
184#define REG_IGNORE_ONE(LOC)		\
185	if (!ret)			\
186		user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
187			offsetof(struct user_regs_struct, LOC), \
188			offsetof(struct user_regs_struct, LOC) + 4);
189
190	REG_IGNORE_ONE(pad);
191
192	REG_IN_ONE(scratch.bta, &ptregs->bta);
193	REG_IN_ONE(scratch.lp_start, &ptregs->lp_start);
194	REG_IN_ONE(scratch.lp_end, &ptregs->lp_end);
195	REG_IN_ONE(scratch.lp_count, &ptregs->lp_count);
196
197	REG_IGNORE_ONE(scratch.status32);
198
199	REG_IN_ONE(scratch.ret, &ptregs->ret);
200	REG_IN_ONE(scratch.blink, &ptregs->blink);
201	REG_IN_ONE(scratch.fp, &ptregs->fp);
202	REG_IN_ONE(scratch.gp, &ptregs->r26);
203	REG_IN_ONE(scratch.r12, &ptregs->r12);
204	REG_IN_ONE(scratch.r11, &ptregs->r11);
205	REG_IN_ONE(scratch.r10, &ptregs->r10);
206	REG_IN_ONE(scratch.r9, &ptregs->r9);
207	REG_IN_ONE(scratch.r8, &ptregs->r8);
208	REG_IN_ONE(scratch.r7, &ptregs->r7);
209	REG_IN_ONE(scratch.r6, &ptregs->r6);
210	REG_IN_ONE(scratch.r5, &ptregs->r5);
211	REG_IN_ONE(scratch.r4, &ptregs->r4);
212	REG_IN_ONE(scratch.r3, &ptregs->r3);
213	REG_IN_ONE(scratch.r2, &ptregs->r2);
214	REG_IN_ONE(scratch.r1, &ptregs->r1);
215	REG_IN_ONE(scratch.r0, &ptregs->r0);
216	REG_IN_ONE(scratch.sp, &ptregs->sp);
217
218	REG_IGNORE_ONE(pad2);
219
220	REG_IN_ONE(callee.r25, &cregs->r25);
221	REG_IN_ONE(callee.r24, &cregs->r24);
222	REG_IN_ONE(callee.r23, &cregs->r23);
223	REG_IN_ONE(callee.r22, &cregs->r22);
224	REG_IN_ONE(callee.r21, &cregs->r21);
225	REG_IN_ONE(callee.r20, &cregs->r20);
226	REG_IN_ONE(callee.r19, &cregs->r19);
227	REG_IN_ONE(callee.r18, &cregs->r18);
228	REG_IN_ONE(callee.r17, &cregs->r17);
229	REG_IN_ONE(callee.r16, &cregs->r16);
230	REG_IN_ONE(callee.r15, &cregs->r15);
231	REG_IN_ONE(callee.r14, &cregs->r14);
232	REG_IN_ONE(callee.r13, &cregs->r13);
233
234	REG_IGNORE_ONE(efa);			/* efa update invalid */
235	REG_IGNORE_ONE(stop_pc);		/* PC updated via @ret */
236
237	return ret;
238}
239
240#ifdef CONFIG_ISA_ARCV2
241static int arcv2regs_get(struct task_struct *target,
242		       const struct user_regset *regset,
243		       struct membuf to)
244{
245	const struct pt_regs *regs = task_pt_regs(target);
246
247	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
248		/*
249		 * itemized copy not needed like above as layout of regs (r30,r58,r59)
250		 * is exactly same in kernel (pt_regs) and userspace (user_regs_arcv2)
251		 */
252		return membuf_write(&to, &regs->r30, sizeof(struct user_regs_arcv2));
253
254
255	membuf_write(&to, &regs->r30, 4); /* r30 only */
256	return membuf_zero(&to, sizeof(struct user_regs_arcv2) - 4);
257}
258
259static int arcv2regs_set(struct task_struct *target,
260		       const struct user_regset *regset,
261		       unsigned int pos, unsigned int count,
262		       const void *kbuf, const void __user *ubuf)
263{
264	const struct pt_regs *regs = task_pt_regs(target);
265	int ret, copy_sz;
266
267	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
268		copy_sz = sizeof(struct user_regs_arcv2);
269	else
270		copy_sz = 4;	/* r30 only */
271
272	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, (void *)&regs->r30,
273				  0, copy_sz);
274
275	return ret;
276}
277
278#endif
279
280enum arc_getset {
281	REGSET_CMN,
282	REGSET_ARCV2,
283};
284
285static const struct user_regset arc_regsets[] = {
286	[REGSET_CMN] = {
287	       .core_note_type = NT_PRSTATUS,
288	       .n = ELF_NGREG,
289	       .size = sizeof(unsigned long),
290	       .align = sizeof(unsigned long),
291	       .regset_get = genregs_get,
292	       .set = genregs_set,
293	},
294#ifdef CONFIG_ISA_ARCV2
295	[REGSET_ARCV2] = {
296	       .core_note_type = NT_ARC_V2,
297	       .n = ELF_ARCV2REG,
298	       .size = sizeof(unsigned long),
299	       .align = sizeof(unsigned long),
300	       .regset_get = arcv2regs_get,
301	       .set = arcv2regs_set,
302	},
303#endif
304};
305
306static const struct user_regset_view user_arc_view = {
307	.name		= "arc",
308	.e_machine	= EM_ARC_INUSE,
309	.regsets	= arc_regsets,
310	.n		= ARRAY_SIZE(arc_regsets)
311};
312
313const struct user_regset_view *task_user_regset_view(struct task_struct *task)
314{
315	return &user_arc_view;
316}
317
318void ptrace_disable(struct task_struct *child)
319{
320}
321
322long arch_ptrace(struct task_struct *child, long request,
323		 unsigned long addr, unsigned long data)
324{
325	int ret = -EIO;
326
327	pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);
328
329	switch (request) {
330	case PTRACE_GET_THREAD_AREA:
331		ret = put_user(task_thread_info(child)->thr_ptr,
332			       (unsigned long __user *)data);
333		break;
334	default:
335		ret = ptrace_request(child, request, addr, data);
336		break;
337	}
338
339	return ret;
340}
341
342asmlinkage int syscall_trace_enter(struct pt_regs *regs)
343{
344	if (test_thread_flag(TIF_SYSCALL_TRACE))
345		if (ptrace_report_syscall_entry(regs))
346			return ULONG_MAX;
347
348#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
349	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
350		trace_sys_enter(regs, syscall_get_nr(current, regs));
351#endif
352
353	return regs->r8;
354}
355
356asmlinkage void syscall_trace_exit(struct pt_regs *regs)
357{
358	if (test_thread_flag(TIF_SYSCALL_TRACE))
359		ptrace_report_syscall_exit(regs, 0);
360
361#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
362	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
363		trace_sys_exit(regs, regs_return_value(regs));
364#endif
365}
366
367int regs_query_register_offset(const char *name)
368{
369	const struct pt_regs_offset *roff;
370
371	for (roff = regoffset_table; roff->name != NULL; roff++)
372		if (!strcmp(roff->name, name))
373			return roff->offset;
374	return -EINVAL;
375}
376
377const char *regs_query_register_name(unsigned int offset)
378{
379	const struct pt_regs_offset *roff;
380	for (roff = regoffset_table; roff->name != NULL; roff++)
381		if (roff->offset == offset)
382			return roff->name;
383	return NULL;
384}
385
386bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
387{
388	return (addr & ~(THREAD_SIZE - 1))  ==
389		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
390}
391
392unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
393{
394	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
395
396	addr += n;
397	if (regs_within_kernel_stack(regs, (unsigned long)addr))
398		return *addr;
399	else
400		return 0;
401}
402