xref: /openbmc/linux/arch/csky/kernel/ptrace.c (revision 78bb17f7)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3 
4 #include <linux/audit.h>
5 #include <linux/elf.h>
6 #include <linux/errno.h>
7 #include <linux/kernel.h>
8 #include <linux/mm.h>
9 #include <linux/ptrace.h>
10 #include <linux/regset.h>
11 #include <linux/sched.h>
12 #include <linux/sched/task_stack.h>
13 #include <linux/signal.h>
14 #include <linux/smp.h>
15 #include <linux/tracehook.h>
16 #include <linux/uaccess.h>
17 #include <linux/user.h>
18 
19 #include <asm/thread_info.h>
20 #include <asm/page.h>
21 #include <asm/pgtable.h>
22 #include <asm/processor.h>
23 #include <asm/asm-offsets.h>
24 
25 #include <abi/regdef.h>
26 
27 #define CREATE_TRACE_POINTS
28 #include <trace/events/syscalls.h>
29 
30 /* sets the trace bits. */
31 #define TRACE_MODE_SI      (1 << 14)
32 #define TRACE_MODE_RUN     0
33 #define TRACE_MODE_MASK    ~(0x3 << 14)
34 
35 /*
36  * Make sure the single step bit is not set.
37  */
38 static void singlestep_disable(struct task_struct *tsk)
39 {
40 	struct pt_regs *regs;
41 
42 	regs = task_pt_regs(tsk);
43 	regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_RUN;
44 
45 	/* Enable irq */
46 	regs->sr |= BIT(6);
47 }
48 
49 static void singlestep_enable(struct task_struct *tsk)
50 {
51 	struct pt_regs *regs;
52 
53 	regs = task_pt_regs(tsk);
54 	regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_SI;
55 
56 	/* Disable irq */
57 	regs->sr &= ~BIT(6);
58 }
59 
60 /*
61  * Make sure the single step bit is set.
62  */
63 void user_enable_single_step(struct task_struct *child)
64 {
65 	singlestep_enable(child);
66 }
67 
68 void user_disable_single_step(struct task_struct *child)
69 {
70 	singlestep_disable(child);
71 }
72 
73 enum csky_regset {
74 	REGSET_GPR,
75 	REGSET_FPR,
76 };
77 
78 static int gpr_get(struct task_struct *target,
79 		   const struct user_regset *regset,
80 		   unsigned int pos, unsigned int count,
81 		   void *kbuf, void __user *ubuf)
82 {
83 	struct pt_regs *regs;
84 
85 	regs = task_pt_regs(target);
86 
87 	/* Abiv1 regs->tls is fake and we need sync here. */
88 	regs->tls = task_thread_info(target)->tp_value;
89 
90 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
91 }
92 
93 static int gpr_set(struct task_struct *target,
94 		    const struct user_regset *regset,
95 		    unsigned int pos, unsigned int count,
96 		    const void *kbuf, const void __user *ubuf)
97 {
98 	int ret;
99 	struct pt_regs regs;
100 
101 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0, -1);
102 	if (ret)
103 		return ret;
104 
105 	regs.sr = task_pt_regs(target)->sr;
106 #ifdef CONFIG_CPU_HAS_HILO
107 	regs.dcsr = task_pt_regs(target)->dcsr;
108 #endif
109 	task_thread_info(target)->tp_value = regs.tls;
110 
111 	*task_pt_regs(target) = regs;
112 
113 	return 0;
114 }
115 
116 static int fpr_get(struct task_struct *target,
117 		   const struct user_regset *regset,
118 		   unsigned int pos, unsigned int count,
119 		   void *kbuf, void __user *ubuf)
120 {
121 	struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
122 
123 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
124 	int i;
125 	struct user_fp tmp = *regs;
126 
127 	for (i = 0; i < 16; i++) {
128 		tmp.vr[i*4] = regs->vr[i*2];
129 		tmp.vr[i*4 + 1] = regs->vr[i*2 + 1];
130 	}
131 
132 	for (i = 0; i < 32; i++)
133 		tmp.vr[64 + i] = regs->vr[32 + i];
134 
135 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
136 #else
137 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
138 #endif
139 }
140 
141 static int fpr_set(struct task_struct *target,
142 		   const struct user_regset *regset,
143 		   unsigned int pos, unsigned int count,
144 		   const void *kbuf, const void __user *ubuf)
145 {
146 	int ret;
147 	struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
148 
149 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
150 	int i;
151 	struct user_fp tmp;
152 
153 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
154 
155 	*regs = tmp;
156 
157 	for (i = 0; i < 16; i++) {
158 		regs->vr[i*2] = tmp.vr[i*4];
159 		regs->vr[i*2 + 1] = tmp.vr[i*4 + 1];
160 	}
161 
162 	for (i = 0; i < 32; i++)
163 		regs->vr[32 + i] = tmp.vr[64 + i];
164 #else
165 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
166 #endif
167 
168 	return ret;
169 }
170 
171 static const struct user_regset csky_regsets[] = {
172 	[REGSET_GPR] = {
173 		.core_note_type = NT_PRSTATUS,
174 		.n = sizeof(struct pt_regs) / sizeof(u32),
175 		.size = sizeof(u32),
176 		.align = sizeof(u32),
177 		.get = &gpr_get,
178 		.set = &gpr_set,
179 	},
180 	[REGSET_FPR] = {
181 		.core_note_type = NT_PRFPREG,
182 		.n = sizeof(struct user_fp) / sizeof(u32),
183 		.size = sizeof(u32),
184 		.align = sizeof(u32),
185 		.get = &fpr_get,
186 		.set = &fpr_set,
187 	},
188 };
189 
190 static const struct user_regset_view user_csky_view = {
191 	.name = "csky",
192 	.e_machine = ELF_ARCH,
193 	.regsets = csky_regsets,
194 	.n = ARRAY_SIZE(csky_regsets),
195 };
196 
197 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
198 {
199 	return &user_csky_view;
200 }
201 
202 struct pt_regs_offset {
203 	const char *name;
204 	int offset;
205 };
206 
207 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
208 #define REG_OFFSET_END {.name = NULL, .offset = 0}
209 
210 static const struct pt_regs_offset regoffset_table[] = {
211 	REG_OFFSET_NAME(tls),
212 	REG_OFFSET_NAME(lr),
213 	REG_OFFSET_NAME(pc),
214 	REG_OFFSET_NAME(sr),
215 	REG_OFFSET_NAME(usp),
216 	REG_OFFSET_NAME(orig_a0),
217 	REG_OFFSET_NAME(a0),
218 	REG_OFFSET_NAME(a1),
219 	REG_OFFSET_NAME(a2),
220 	REG_OFFSET_NAME(a3),
221 	REG_OFFSET_NAME(regs[0]),
222 	REG_OFFSET_NAME(regs[1]),
223 	REG_OFFSET_NAME(regs[2]),
224 	REG_OFFSET_NAME(regs[3]),
225 	REG_OFFSET_NAME(regs[4]),
226 	REG_OFFSET_NAME(regs[5]),
227 	REG_OFFSET_NAME(regs[6]),
228 	REG_OFFSET_NAME(regs[7]),
229 	REG_OFFSET_NAME(regs[8]),
230 	REG_OFFSET_NAME(regs[9]),
231 #if defined(__CSKYABIV2__)
232 	REG_OFFSET_NAME(exregs[0]),
233 	REG_OFFSET_NAME(exregs[1]),
234 	REG_OFFSET_NAME(exregs[2]),
235 	REG_OFFSET_NAME(exregs[3]),
236 	REG_OFFSET_NAME(exregs[4]),
237 	REG_OFFSET_NAME(exregs[5]),
238 	REG_OFFSET_NAME(exregs[6]),
239 	REG_OFFSET_NAME(exregs[7]),
240 	REG_OFFSET_NAME(exregs[8]),
241 	REG_OFFSET_NAME(exregs[9]),
242 	REG_OFFSET_NAME(exregs[10]),
243 	REG_OFFSET_NAME(exregs[11]),
244 	REG_OFFSET_NAME(exregs[12]),
245 	REG_OFFSET_NAME(exregs[13]),
246 	REG_OFFSET_NAME(exregs[14]),
247 	REG_OFFSET_NAME(rhi),
248 	REG_OFFSET_NAME(rlo),
249 	REG_OFFSET_NAME(dcsr),
250 #endif
251 	REG_OFFSET_END,
252 };
253 
254 /**
255  * regs_query_register_offset() - query register offset from its name
256  * @name:	the name of a register
257  *
258  * regs_query_register_offset() returns the offset of a register in struct
259  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
260  */
261 int regs_query_register_offset(const char *name)
262 {
263 	const struct pt_regs_offset *roff;
264 
265 	for (roff = regoffset_table; roff->name != NULL; roff++)
266 		if (!strcmp(roff->name, name))
267 			return roff->offset;
268 	return -EINVAL;
269 }
270 
271 /**
272  * regs_within_kernel_stack() - check the address in the stack
273  * @regs:      pt_regs which contains kernel stack pointer.
274  * @addr:      address which is checked.
275  *
276  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
277  * If @addr is within the kernel stack, it returns true. If not, returns false.
278  */
279 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
280 {
281 	return (addr & ~(THREAD_SIZE - 1))  ==
282 		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
283 }
284 
285 /**
286  * regs_get_kernel_stack_nth() - get Nth entry of the stack
287  * @regs:	pt_regs which contains kernel stack pointer.
288  * @n:		stack entry number.
289  *
290  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
291  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
292  * this returns 0.
293  */
294 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
295 {
296 	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
297 
298 	addr += n;
299 	if (regs_within_kernel_stack(regs, (unsigned long)addr))
300 		return *addr;
301 	else
302 		return 0;
303 }
304 
305 void ptrace_disable(struct task_struct *child)
306 {
307 	singlestep_disable(child);
308 }
309 
310 long arch_ptrace(struct task_struct *child, long request,
311 		 unsigned long addr, unsigned long data)
312 {
313 	long ret = -EIO;
314 
315 	switch (request) {
316 	default:
317 		ret = ptrace_request(child, request, addr, data);
318 		break;
319 	}
320 
321 	return ret;
322 }
323 
324 asmlinkage void syscall_trace_enter(struct pt_regs *regs)
325 {
326 	if (test_thread_flag(TIF_SYSCALL_TRACE))
327 		if (tracehook_report_syscall_entry(regs))
328 			syscall_set_nr(current, regs, -1);
329 
330 	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
331 		trace_sys_enter(regs, syscall_get_nr(current, regs));
332 
333 	audit_syscall_entry(regs_syscallid(regs), regs->a0, regs->a1, regs->a2, regs->a3);
334 }
335 
336 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
337 {
338 	audit_syscall_exit(regs);
339 
340 	if (test_thread_flag(TIF_SYSCALL_TRACE))
341 		tracehook_report_syscall_exit(regs, 0);
342 
343 	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
344 		trace_sys_exit(regs, syscall_get_return_value(current, regs));
345 }
346 
347 extern void show_stack(struct task_struct *task, unsigned long *stack);
348 void show_regs(struct pt_regs *fp)
349 {
350 	unsigned long   *sp;
351 	unsigned char   *tp;
352 	int	i;
353 
354 	pr_info("\nCURRENT PROCESS:\n\n");
355 	pr_info("COMM=%s PID=%d\n", current->comm, current->pid);
356 
357 	if (current->mm) {
358 		pr_info("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
359 		       (int) current->mm->start_code,
360 		       (int) current->mm->end_code,
361 		       (int) current->mm->start_data,
362 		       (int) current->mm->end_data,
363 		       (int) current->mm->end_data,
364 		       (int) current->mm->brk);
365 		pr_info("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
366 		       (int) current->mm->start_stack,
367 		       (int) (((unsigned long) current) + 2 * PAGE_SIZE));
368 	}
369 
370 	pr_info("PC: 0x%08lx (%pS)\n", (long)fp->pc, (void *)fp->pc);
371 	pr_info("LR: 0x%08lx (%pS)\n", (long)fp->lr, (void *)fp->lr);
372 	pr_info("SP: 0x%08lx\n", (long)fp);
373 	pr_info("orig_a0: 0x%08lx\n", fp->orig_a0);
374 	pr_info("PSR: 0x%08lx\n", (long)fp->sr);
375 
376 	pr_info(" a0: 0x%08lx   a1: 0x%08lx   a2: 0x%08lx   a3: 0x%08lx\n",
377 		fp->a0, fp->a1, fp->a2, fp->a3);
378 #if defined(__CSKYABIV2__)
379 	pr_info(" r4: 0x%08lx   r5: 0x%08lx   r6: 0x%08lx   r7: 0x%08lx\n",
380 		fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
381 	pr_info(" r8: 0x%08lx   r9: 0x%08lx  r10: 0x%08lx  r11: 0x%08lx\n",
382 		fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
383 	pr_info("r12: 0x%08lx  r13: 0x%08lx  r15: 0x%08lx\n",
384 		fp->regs[8], fp->regs[9], fp->lr);
385 	pr_info("r16: 0x%08lx  r17: 0x%08lx  r18: 0x%08lx  r19: 0x%08lx\n",
386 		fp->exregs[0], fp->exregs[1], fp->exregs[2], fp->exregs[3]);
387 	pr_info("r20: 0x%08lx  r21: 0x%08lx  r22: 0x%08lx  r23: 0x%08lx\n",
388 		fp->exregs[4], fp->exregs[5], fp->exregs[6], fp->exregs[7]);
389 	pr_info("r24: 0x%08lx  r25: 0x%08lx  r26: 0x%08lx  r27: 0x%08lx\n",
390 		fp->exregs[8], fp->exregs[9], fp->exregs[10], fp->exregs[11]);
391 	pr_info("r28: 0x%08lx  r29: 0x%08lx  r30: 0x%08lx  tls: 0x%08lx\n",
392 		fp->exregs[12], fp->exregs[13], fp->exregs[14], fp->tls);
393 	pr_info(" hi: 0x%08lx   lo: 0x%08lx\n",
394 		fp->rhi, fp->rlo);
395 #else
396 	pr_info(" r6: 0x%08lx   r7: 0x%08lx   r8: 0x%08lx   r9: 0x%08lx\n",
397 		fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
398 	pr_info("r10: 0x%08lx  r11: 0x%08lx  r12: 0x%08lx  r13: 0x%08lx\n",
399 		fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
400 	pr_info("r14: 0x%08lx   r1: 0x%08lx  r15: 0x%08lx\n",
401 		fp->regs[8], fp->regs[9], fp->lr);
402 #endif
403 
404 	pr_info("\nCODE:");
405 	tp = ((unsigned char *) fp->pc) - 0x20;
406 	tp += ((int)tp % 4) ? 2 : 0;
407 	for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
408 		if ((i % 0x10) == 0)
409 			pr_cont("\n%08x: ", (int) (tp + i));
410 		pr_cont("%08x ", (int) *sp++);
411 	}
412 	pr_cont("\n");
413 
414 	pr_info("\nKERNEL STACK:");
415 	tp = ((unsigned char *) fp) - 0x40;
416 	for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
417 		if ((i % 0x10) == 0)
418 			pr_cont("\n%08x: ", (int) (tp + i));
419 		pr_cont("%08x ", (int) *sp++);
420 	}
421 	pr_cont("\n");
422 
423 	show_stack(NULL, (unsigned long *)fp->regs[4]);
424 	return;
425 }
426