1// TODO some minor issues
2/*
3 * This file is subject to the terms and conditions of the GNU General Public
4 * License.  See the file "COPYING" in the main directory of this archive
5 * for more details.
6 *
7 * Copyright (C) 2001 - 2007  Tensilica Inc.
8 *
9 * Joe Taylor	<joe@tensilica.com, joetylr@yahoo.com>
10 * Chris Zankel <chris@zankel.net>
11 * Scott Foehner<sfoehner@yahoo.com>,
12 * Kevin Chea
13 * Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca>
14 */
15
16#include <linux/kernel.h>
17#include <linux/sched.h>
18#include <linux/mm.h>
19#include <linux/errno.h>
20#include <linux/ptrace.h>
21#include <linux/smp.h>
22#include <linux/security.h>
23#include <linux/signal.h>
24
25#include <asm/pgtable.h>
26#include <asm/page.h>
27#include <asm/uaccess.h>
28#include <asm/ptrace.h>
29#include <asm/elf.h>
30#include <asm/coprocessor.h>
31
32
33void user_enable_single_step(struct task_struct *child)
34{
35	child->ptrace |= PT_SINGLESTEP;
36}
37
38void user_disable_single_step(struct task_struct *child)
39{
40	child->ptrace &= ~PT_SINGLESTEP;
41}
42
43/*
44 * Called by kernel/ptrace.c when detaching to disable single stepping.
45 */
46
47void ptrace_disable(struct task_struct *child)
48{
49	/* Nothing to do.. */
50}
51
52int ptrace_getregs(struct task_struct *child, void __user *uregs)
53{
54	struct pt_regs *regs = task_pt_regs(child);
55	xtensa_gregset_t __user *gregset = uregs;
56	unsigned long wb = regs->windowbase;
57	int i;
58
59	if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
60		return -EIO;
61
62	__put_user(regs->pc, &gregset->pc);
63	__put_user(regs->ps & ~(1 << PS_EXCM_BIT), &gregset->ps);
64	__put_user(regs->lbeg, &gregset->lbeg);
65	__put_user(regs->lend, &gregset->lend);
66	__put_user(regs->lcount, &gregset->lcount);
67	__put_user(regs->windowstart, &gregset->windowstart);
68	__put_user(regs->windowbase, &gregset->windowbase);
69	__put_user(regs->threadptr, &gregset->threadptr);
70
71	for (i = 0; i < XCHAL_NUM_AREGS; i++)
72		__put_user(regs->areg[i],
73				gregset->a + ((wb * 4 + i) % XCHAL_NUM_AREGS));
74
75	return 0;
76}
77
78int ptrace_setregs(struct task_struct *child, void __user *uregs)
79{
80	struct pt_regs *regs = task_pt_regs(child);
81	xtensa_gregset_t *gregset = uregs;
82	const unsigned long ps_mask = PS_CALLINC_MASK | PS_OWB_MASK;
83	unsigned long ps;
84	unsigned long wb, ws;
85
86	if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
87		return -EIO;
88
89	__get_user(regs->pc, &gregset->pc);
90	__get_user(ps, &gregset->ps);
91	__get_user(regs->lbeg, &gregset->lbeg);
92	__get_user(regs->lend, &gregset->lend);
93	__get_user(regs->lcount, &gregset->lcount);
94	__get_user(ws, &gregset->windowstart);
95	__get_user(wb, &gregset->windowbase);
96	__get_user(regs->threadptr, &gregset->threadptr);
97
98	regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT);
99
100	if (wb >= XCHAL_NUM_AREGS / 4)
101		return -EFAULT;
102
103	if (wb != regs->windowbase || ws != regs->windowstart) {
104		unsigned long rotws, wmask;
105
106		rotws = (((ws | (ws << WSBITS)) >> wb) &
107				((1 << WSBITS) - 1)) & ~1;
108		wmask = ((rotws ? WSBITS + 1 - ffs(rotws) : 0) << 4) |
109			(rotws & 0xF) | 1;
110		regs->windowbase = wb;
111		regs->windowstart = ws;
112		regs->wmask = wmask;
113	}
114
115	if (wb != 0 &&  __copy_from_user(regs->areg + XCHAL_NUM_AREGS - wb * 4,
116				gregset->a, wb * 16))
117		return -EFAULT;
118
119	if (__copy_from_user(regs->areg, gregset->a + wb * 4,
120				(WSBITS - wb) * 16))
121		return -EFAULT;
122
123	return 0;
124}
125
126
127int ptrace_getxregs(struct task_struct *child, void __user *uregs)
128{
129	struct pt_regs *regs = task_pt_regs(child);
130	struct thread_info *ti = task_thread_info(child);
131	elf_xtregs_t __user *xtregs = uregs;
132	int ret = 0;
133
134	if (!access_ok(VERIFY_WRITE, uregs, sizeof(elf_xtregs_t)))
135		return -EIO;
136
137#if XTENSA_HAVE_COPROCESSORS
138	/* Flush all coprocessor registers to memory. */
139	coprocessor_flush_all(ti);
140	ret |= __copy_to_user(&xtregs->cp0, &ti->xtregs_cp,
141			      sizeof(xtregs_coprocessor_t));
142#endif
143	ret |= __copy_to_user(&xtregs->opt, &regs->xtregs_opt,
144			      sizeof(xtregs->opt));
145	ret |= __copy_to_user(&xtregs->user,&ti->xtregs_user,
146			      sizeof(xtregs->user));
147
148	return ret ? -EFAULT : 0;
149}
150
151int ptrace_setxregs(struct task_struct *child, void __user *uregs)
152{
153	struct thread_info *ti = task_thread_info(child);
154	struct pt_regs *regs = task_pt_regs(child);
155	elf_xtregs_t *xtregs = uregs;
156	int ret = 0;
157
158	if (!access_ok(VERIFY_READ, uregs, sizeof(elf_xtregs_t)))
159		return -EFAULT;
160
161#if XTENSA_HAVE_COPROCESSORS
162	/* Flush all coprocessors before we overwrite them. */
163	coprocessor_flush_all(ti);
164	coprocessor_release_all(ti);
165
166	ret |= __copy_from_user(&ti->xtregs_cp, &xtregs->cp0,
167				sizeof(xtregs_coprocessor_t));
168#endif
169	ret |= __copy_from_user(&regs->xtregs_opt, &xtregs->opt,
170				sizeof(xtregs->opt));
171	ret |= __copy_from_user(&ti->xtregs_user, &xtregs->user,
172				sizeof(xtregs->user));
173
174	return ret ? -EFAULT : 0;
175}
176
177int ptrace_peekusr(struct task_struct *child, long regno, long __user *ret)
178{
179	struct pt_regs *regs;
180	unsigned long tmp;
181
182	regs = task_pt_regs(child);
183	tmp = 0;  /* Default return value. */
184
185	switch(regno) {
186
187		case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
188			tmp = regs->areg[regno - REG_AR_BASE];
189			break;
190
191		case REG_A_BASE ... REG_A_BASE + 15:
192			tmp = regs->areg[regno - REG_A_BASE];
193			break;
194
195		case REG_PC:
196			tmp = regs->pc;
197			break;
198
199		case REG_PS:
200			/* Note:  PS.EXCM is not set while user task is running;
201			 * its being set in regs is for exception handling
202			 * convenience.  */
203			tmp = (regs->ps & ~(1 << PS_EXCM_BIT));
204			break;
205
206		case REG_WB:
207			break;		/* tmp = 0 */
208
209		case REG_WS:
210		{
211			unsigned long wb = regs->windowbase;
212			unsigned long ws = regs->windowstart;
213			tmp = ((ws>>wb) | (ws<<(WSBITS-wb))) & ((1<<WSBITS)-1);
214			break;
215		}
216		case REG_LBEG:
217			tmp = regs->lbeg;
218			break;
219
220		case REG_LEND:
221			tmp = regs->lend;
222			break;
223
224		case REG_LCOUNT:
225			tmp = regs->lcount;
226			break;
227
228		case REG_SAR:
229			tmp = regs->sar;
230			break;
231
232		case SYSCALL_NR:
233			tmp = regs->syscall;
234			break;
235
236		default:
237			return -EIO;
238	}
239	return put_user(tmp, ret);
240}
241
242int ptrace_pokeusr(struct task_struct *child, long regno, long val)
243{
244	struct pt_regs *regs;
245	regs = task_pt_regs(child);
246
247	switch (regno) {
248		case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
249			regs->areg[regno - REG_AR_BASE] = val;
250			break;
251
252		case REG_A_BASE ... REG_A_BASE + 15:
253			regs->areg[regno - REG_A_BASE] = val;
254			break;
255
256		case REG_PC:
257			regs->pc = val;
258			break;
259
260		case SYSCALL_NR:
261			regs->syscall = val;
262			break;
263
264		default:
265			return -EIO;
266	}
267	return 0;
268}
269
270long arch_ptrace(struct task_struct *child, long request,
271		 unsigned long addr, unsigned long data)
272{
273	int ret = -EPERM;
274	void __user *datap = (void __user *) data;
275
276	switch (request) {
277	case PTRACE_PEEKTEXT:	/* read word at location addr. */
278	case PTRACE_PEEKDATA:
279		ret = generic_ptrace_peekdata(child, addr, data);
280		break;
281
282	case PTRACE_PEEKUSR:	/* read register specified by addr. */
283		ret = ptrace_peekusr(child, addr, datap);
284		break;
285
286	case PTRACE_POKETEXT:	/* write the word at location addr. */
287	case PTRACE_POKEDATA:
288		ret = generic_ptrace_pokedata(child, addr, data);
289		break;
290
291	case PTRACE_POKEUSR:	/* write register specified by addr. */
292		ret = ptrace_pokeusr(child, addr, data);
293		break;
294
295	case PTRACE_GETREGS:
296		ret = ptrace_getregs(child, datap);
297		break;
298
299	case PTRACE_SETREGS:
300		ret = ptrace_setregs(child, datap);
301		break;
302
303	case PTRACE_GETXTREGS:
304		ret = ptrace_getxregs(child, datap);
305		break;
306
307	case PTRACE_SETXTREGS:
308		ret = ptrace_setxregs(child, datap);
309		break;
310
311	default:
312		ret = ptrace_request(child, request, addr, data);
313		break;
314	}
315
316	return ret;
317}
318
319void do_syscall_trace(void)
320{
321	/*
322	 * The 0x80 provides a way for the tracing parent to distinguish
323	 * between a syscall stop and SIGTRAP delivery
324	 */
325	ptrace_notify(SIGTRAP|((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
326
327	/*
328	 * this isn't the same as continuing with a signal, but it will do
329	 * for normal use.  strace only continues with a signal if the
330	 * stopping signal is not SIGTRAP.  -brl
331	 */
332	if (current->exit_code) {
333		send_sig(current->exit_code, current, 1);
334		current->exit_code = 0;
335	}
336}
337
338void do_syscall_trace_enter(struct pt_regs *regs)
339{
340	if (test_thread_flag(TIF_SYSCALL_TRACE)
341			&& (current->ptrace & PT_PTRACED))
342		do_syscall_trace();
343
344#if 0
345	audit_syscall_entry(...);
346#endif
347}
348
349void do_syscall_trace_leave(struct pt_regs *regs)
350{
351	if ((test_thread_flag(TIF_SYSCALL_TRACE))
352			&& (current->ptrace & PT_PTRACED))
353		do_syscall_trace();
354}
355