xref: /openbmc/linux/arch/csky/kernel/ptrace.c (revision 0c874100)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3 
4 #include <linux/elf.h>
5 #include <linux/errno.h>
6 #include <linux/kernel.h>
7 #include <linux/mm.h>
8 #include <linux/ptrace.h>
9 #include <linux/regset.h>
10 #include <linux/sched.h>
11 #include <linux/signal.h>
12 #include <linux/smp.h>
13 #include <linux/uaccess.h>
14 #include <linux/user.h>
15 
16 #include <asm/thread_info.h>
17 #include <asm/page.h>
18 #include <asm/pgtable.h>
19 #include <asm/processor.h>
20 #include <asm/asm-offsets.h>
21 
22 #include <abi/regdef.h>
23 
24 /* sets the trace bits. */
25 #define TRACE_MODE_SI      (1 << 14)
26 #define TRACE_MODE_RUN     0
27 #define TRACE_MODE_MASK    ~(0x3 << 14)
28 
29 /*
30  * Make sure the single step bit is not set.
31  */
32 static void singlestep_disable(struct task_struct *tsk)
33 {
34 	struct pt_regs *regs;
35 
36 	regs = task_pt_regs(tsk);
37 	regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_RUN;
38 }
39 
40 static void singlestep_enable(struct task_struct *tsk)
41 {
42 	struct pt_regs *regs;
43 
44 	regs = task_pt_regs(tsk);
45 	regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_SI;
46 }
47 
48 /*
49  * Make sure the single step bit is set.
50  */
51 void user_enable_single_step(struct task_struct *child)
52 {
53 	if (child->thread.esp0 == 0)
54 		return;
55 	singlestep_enable(child);
56 }
57 
58 void user_disable_single_step(struct task_struct *child)
59 {
60 	if (child->thread.esp0 == 0)
61 		return;
62 	singlestep_disable(child);
63 }
64 
65 enum csky_regset {
66 	REGSET_GPR,
67 	REGSET_FPR,
68 };
69 
70 static int gpr_get(struct task_struct *target,
71 		   const struct user_regset *regset,
72 		   unsigned int pos, unsigned int count,
73 		   void *kbuf, void __user *ubuf)
74 {
75 	struct pt_regs *regs;
76 
77 	regs = task_pt_regs(target);
78 
79 	/* Abiv1 regs->tls is fake and we need sync here. */
80 	regs->tls = task_thread_info(target)->tp_value;
81 
82 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
83 }
84 
85 static int gpr_set(struct task_struct *target,
86 		    const struct user_regset *regset,
87 		    unsigned int pos, unsigned int count,
88 		    const void *kbuf, const void __user *ubuf)
89 {
90 	int ret;
91 	struct pt_regs regs;
92 
93 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0, -1);
94 	if (ret)
95 		return ret;
96 
97 	regs.sr = task_pt_regs(target)->sr;
98 
99 	task_thread_info(target)->tp_value = regs.tls;
100 
101 	*task_pt_regs(target) = regs;
102 
103 	return 0;
104 }
105 
106 static int fpr_get(struct task_struct *target,
107 		   const struct user_regset *regset,
108 		   unsigned int pos, unsigned int count,
109 		   void *kbuf, void __user *ubuf)
110 {
111 	struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
112 
113 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
114 	int i;
115 	struct user_fp tmp = *regs;
116 
117 	for (i = 0; i < 16; i++) {
118 		tmp.vr[i*4] = regs->vr[i*2];
119 		tmp.vr[i*4 + 1] = regs->vr[i*2 + 1];
120 	}
121 
122 	for (i = 0; i < 32; i++)
123 		tmp.vr[64 + i] = regs->vr[32 + i];
124 
125 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
126 #else
127 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
128 #endif
129 }
130 
131 static int fpr_set(struct task_struct *target,
132 		   const struct user_regset *regset,
133 		   unsigned int pos, unsigned int count,
134 		   const void *kbuf, const void __user *ubuf)
135 {
136 	int ret;
137 	struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
138 
139 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
140 	int i;
141 	struct user_fp tmp;
142 
143 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
144 
145 	*regs = tmp;
146 
147 	for (i = 0; i < 16; i++) {
148 		regs->vr[i*2] = tmp.vr[i*4];
149 		regs->vr[i*2 + 1] = tmp.vr[i*4 + 1];
150 	}
151 
152 	for (i = 0; i < 32; i++)
153 		regs->vr[32 + i] = tmp.vr[64 + i];
154 #else
155 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
156 #endif
157 
158 	return ret;
159 }
160 
161 static const struct user_regset csky_regsets[] = {
162 	[REGSET_GPR] = {
163 		.core_note_type = NT_PRSTATUS,
164 		.n = ELF_NGREG,
165 		.size = sizeof(u32),
166 		.align = sizeof(u32),
167 		.get = &gpr_get,
168 		.set = &gpr_set,
169 	},
170 	[REGSET_FPR] = {
171 		.core_note_type = NT_PRFPREG,
172 		.n = sizeof(struct user_fp) / sizeof(u32),
173 		.size = sizeof(u32),
174 		.align = sizeof(u32),
175 		.get = &fpr_get,
176 		.set = &fpr_set,
177 	},
178 };
179 
180 static const struct user_regset_view user_csky_view = {
181 	.name = "csky",
182 	.e_machine = ELF_ARCH,
183 	.regsets = csky_regsets,
184 	.n = ARRAY_SIZE(csky_regsets),
185 };
186 
187 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
188 {
189 	return &user_csky_view;
190 }
191 
192 void ptrace_disable(struct task_struct *child)
193 {
194 	singlestep_disable(child);
195 }
196 
197 long arch_ptrace(struct task_struct *child, long request,
198 		 unsigned long addr, unsigned long data)
199 {
200 	long ret = -EIO;
201 
202 	switch (request) {
203 	default:
204 		ret = ptrace_request(child, request, addr, data);
205 		break;
206 	}
207 
208 	return ret;
209 }
210 
211 /*
212  * If process's system calls is traces, do some corresponding handles in this
213  * function before entering system call function and after exiting system call
214  * function.
215  */
216 asmlinkage void syscall_trace(int why, struct pt_regs *regs)
217 {
218 	long saved_why;
219 	/*
220 	 * Save saved_why, why is used to denote syscall entry/exit;
221 	 * why = 0:entry, why = 1: exit
222 	 */
223 	saved_why = regs->regs[SYSTRACE_SAVENUM];
224 	regs->regs[SYSTRACE_SAVENUM] = why;
225 
226 	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
227 					? 0x80 : 0));
228 
229 	/*
230 	 * this isn't the same as continuing with a signal, but it will do
231 	 * for normal use.  strace only continues with a signal if the
232 	 * stopping signal is not SIGTRAP.  -brl
233 	 */
234 	if (current->exit_code) {
235 		send_sig(current->exit_code, current, 1);
236 		current->exit_code = 0;
237 	}
238 
239 	regs->regs[SYSTRACE_SAVENUM] = saved_why;
240 }
241 
242 void show_regs(struct pt_regs *fp)
243 {
244 	unsigned long   *sp;
245 	unsigned char   *tp;
246 	int	i;
247 
248 	pr_info("\nCURRENT PROCESS:\n\n");
249 	pr_info("COMM=%s PID=%d\n", current->comm, current->pid);
250 
251 	if (current->mm) {
252 		pr_info("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
253 		       (int) current->mm->start_code,
254 		       (int) current->mm->end_code,
255 		       (int) current->mm->start_data,
256 		       (int) current->mm->end_data,
257 		       (int) current->mm->end_data,
258 		       (int) current->mm->brk);
259 		pr_info("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
260 		       (int) current->mm->start_stack,
261 		       (int) (((unsigned long) current) + 2 * PAGE_SIZE));
262 	}
263 
264 	pr_info("PC: 0x%08lx\n", (long)fp->pc);
265 	pr_info("orig_a0: 0x%08lx\n", fp->orig_a0);
266 	pr_info("PSR: 0x%08lx\n", (long)fp->sr);
267 
268 	pr_info("a0: 0x%08lx  a1: 0x%08lx  a2: 0x%08lx  a3: 0x%08lx\n",
269 	       fp->a0, fp->a1, fp->a2, fp->a3);
270 #if defined(__CSKYABIV2__)
271 	pr_info("r4: 0x%08lx  r5: 0x%08lx    r6: 0x%08lx    r7: 0x%08lx\n",
272 		fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
273 	pr_info("r8: 0x%08lx  r9: 0x%08lx   r10: 0x%08lx   r11: 0x%08lx\n",
274 		fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
275 	pr_info("r12 0x%08lx  r13: 0x%08lx   r15: 0x%08lx\n",
276 		fp->regs[8], fp->regs[9], fp->lr);
277 	pr_info("r16:0x%08lx   r17: 0x%08lx   r18: 0x%08lx    r19: 0x%08lx\n",
278 		fp->exregs[0], fp->exregs[1], fp->exregs[2], fp->exregs[3]);
279 	pr_info("r20 0x%08lx   r21: 0x%08lx   r22: 0x%08lx    r23: 0x%08lx\n",
280 		fp->exregs[4], fp->exregs[5], fp->exregs[6], fp->exregs[7]);
281 	pr_info("r24 0x%08lx   r25: 0x%08lx   r26: 0x%08lx    r27: 0x%08lx\n",
282 		fp->exregs[8], fp->exregs[9], fp->exregs[10], fp->exregs[11]);
283 	pr_info("r28 0x%08lx   r29: 0x%08lx   r30: 0x%08lx    tls: 0x%08lx\n",
284 		fp->exregs[12], fp->exregs[13], fp->exregs[14], fp->tls);
285 	pr_info("hi 0x%08lx    lo: 0x%08lx\n",
286 		fp->rhi, fp->rlo);
287 #else
288 	pr_info("r6: 0x%08lx   r7: 0x%08lx   r8: 0x%08lx   r9: 0x%08lx\n",
289 		fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
290 	pr_info("r10: 0x%08lx   r11: 0x%08lx   r12: 0x%08lx   r13: 0x%08lx\n",
291 		fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
292 	pr_info("r14 0x%08lx   r1: 0x%08lx   r15: 0x%08lx\n",
293 		fp->regs[8], fp->regs[9], fp->lr);
294 #endif
295 
296 	pr_info("\nCODE:");
297 	tp = ((unsigned char *) fp->pc) - 0x20;
298 	tp += ((int)tp % 4) ? 2 : 0;
299 	for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
300 		if ((i % 0x10) == 0)
301 			pr_cont("\n%08x: ", (int) (tp + i));
302 		pr_cont("%08x ", (int) *sp++);
303 	}
304 	pr_cont("\n");
305 
306 	pr_info("\nKERNEL STACK:");
307 	tp = ((unsigned char *) fp) - 0x40;
308 	for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
309 		if ((i % 0x10) == 0)
310 			pr_cont("\n%08x: ", (int) (tp + i));
311 		pr_cont("%08x ", (int) *sp++);
312 	}
313 	pr_cont("\n");
314 }
315