Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6] / arch / xtensa / kernel / ptrace.c
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/system.h>
28 #include <asm/uaccess.h>
29 #include <asm/ptrace.h>
30 #include <asm/elf.h>
31 #include <asm/coprocessor.h>
32
33 /*
34  * Called by kernel/ptrace.c when detaching to disable single stepping.
35  */
36
37 void ptrace_disable(struct task_struct *child)
38 {
39         /* Nothing to do.. */
40 }
41
42 int ptrace_getregs(struct task_struct *child, void __user *uregs)
43 {
44         struct pt_regs *regs = task_pt_regs(child);
45         xtensa_gregset_t __user *gregset = uregs;
46         unsigned long wm = regs->wmask;
47         unsigned long wb = regs->windowbase;
48         int live, i;
49
50         if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
51                 return -EIO;
52
53         __put_user(regs->pc, &gregset->pc);
54         __put_user(regs->ps & ~(1 << PS_EXCM_BIT), &gregset->ps);
55         __put_user(regs->lbeg, &gregset->lbeg);
56         __put_user(regs->lend, &gregset->lend);
57         __put_user(regs->lcount, &gregset->lcount);
58         __put_user(regs->windowstart, &gregset->windowstart);
59         __put_user(regs->windowbase, &gregset->windowbase);
60
61         live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16;
62
63         for (i = 0; i < live; i++)
64                 __put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS));
65         for (i = XCHAL_NUM_AREGS - (wm >> 4) * 4; i < XCHAL_NUM_AREGS; i++)
66                 __put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS));
67
68         return 0;
69 }
70
71 int ptrace_setregs(struct task_struct *child, void __user *uregs)
72 {
73         struct pt_regs *regs = task_pt_regs(child);
74         xtensa_gregset_t *gregset = uregs;
75         const unsigned long ps_mask = PS_CALLINC_MASK | PS_OWB_MASK;
76         unsigned long ps;
77         unsigned long wb;
78
79         if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
80                 return -EIO;
81
82         __get_user(regs->pc, &gregset->pc);
83         __get_user(ps, &gregset->ps);
84         __get_user(regs->lbeg, &gregset->lbeg);
85         __get_user(regs->lend, &gregset->lend);
86         __get_user(regs->lcount, &gregset->lcount);
87         __get_user(regs->windowstart, &gregset->windowstart);
88         __get_user(wb, &gregset->windowbase);
89
90         regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT);
91
92         if (wb >= XCHAL_NUM_AREGS / 4)
93                 return -EFAULT;
94
95         regs->windowbase = wb;
96
97         if (wb != 0 &&  __copy_from_user(regs->areg + XCHAL_NUM_AREGS - wb * 4,
98                                          gregset->a, wb * 16))
99                 return -EFAULT;
100
101         if (__copy_from_user(regs->areg, gregset->a + wb*4, (WSBITS-wb) * 16))
102                 return -EFAULT;
103
104         return 0;
105 }
106
107
108 int ptrace_getxregs(struct task_struct *child, void __user *uregs)
109 {
110         struct pt_regs *regs = task_pt_regs(child);
111         struct thread_info *ti = task_thread_info(child);
112         elf_xtregs_t __user *xtregs = uregs;
113         int ret = 0;
114
115         if (!access_ok(VERIFY_WRITE, uregs, sizeof(elf_xtregs_t)))
116                 return -EIO;
117
118 #if XTENSA_HAVE_COPROCESSORS
119         /* Flush all coprocessor registers to memory. */
120         coprocessor_flush_all(ti);
121         ret |= __copy_to_user(&xtregs->cp0, &ti->xtregs_cp,
122                               sizeof(xtregs_coprocessor_t));
123 #endif
124         ret |= __copy_to_user(&xtregs->opt, &regs->xtregs_opt,
125                               sizeof(xtregs->opt));
126         ret |= __copy_to_user(&xtregs->user,&ti->xtregs_user,
127                               sizeof(xtregs->user));
128
129         return ret ? -EFAULT : 0;
130 }
131
132 int ptrace_setxregs(struct task_struct *child, void __user *uregs)
133 {
134         struct thread_info *ti = task_thread_info(child);
135         struct pt_regs *regs = task_pt_regs(child);
136         elf_xtregs_t *xtregs = uregs;
137         int ret = 0;
138
139 #if XTENSA_HAVE_COPROCESSORS
140         /* Flush all coprocessors before we overwrite them. */
141         coprocessor_flush_all(ti);
142         coprocessor_release_all(ti);
143
144         ret |= __copy_from_user(&ti->xtregs_cp, &xtregs->cp0, 
145                                 sizeof(xtregs_coprocessor_t));
146 #endif
147         ret |= __copy_from_user(&regs->xtregs_opt, &xtregs->opt,
148                                 sizeof(xtregs->opt));
149         ret |= __copy_from_user(&ti->xtregs_user, &xtregs->user,
150                                 sizeof(xtregs->user));
151
152         return ret ? -EFAULT : 0;
153 }
154
155 int ptrace_peekusr(struct task_struct *child, long regno, long __user *ret)
156 {
157         struct pt_regs *regs;
158         unsigned long tmp;
159
160         regs = task_pt_regs(child);
161         tmp = 0;  /* Default return value. */
162
163         switch(regno) {
164
165                 case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
166                         tmp = regs->areg[regno - REG_AR_BASE];
167                         break;
168
169                 case REG_A_BASE ... REG_A_BASE + 15:
170                         tmp = regs->areg[regno - REG_A_BASE];
171                         break;
172
173                 case REG_PC:
174                         tmp = regs->pc;
175                         break;
176
177                 case REG_PS:
178                         /* Note:  PS.EXCM is not set while user task is running;
179                          * its being set in regs is for exception handling
180                          * convenience.  */
181                         tmp = (regs->ps & ~(1 << PS_EXCM_BIT));
182                         break;
183
184                 case REG_WB:
185                         break;          /* tmp = 0 */
186
187                 case REG_WS:
188                 {
189                         unsigned long wb = regs->windowbase;
190                         unsigned long ws = regs->windowstart;
191                         tmp = ((ws>>wb) | (ws<<(WSBITS-wb))) & ((1<<WSBITS)-1);
192                         break;
193                 }
194                 case REG_LBEG:
195                         tmp = regs->lbeg;
196                         break;
197
198                 case REG_LEND:
199                         tmp = regs->lend;
200                         break;
201
202                 case REG_LCOUNT:
203                         tmp = regs->lcount;
204                         break;
205
206                 case REG_SAR:
207                         tmp = regs->sar;
208                         break;
209
210                 case SYSCALL_NR:
211                         tmp = regs->syscall;
212                         break;
213
214                 default:
215                         return -EIO;
216         }
217         return put_user(tmp, ret);
218 }
219
220 int ptrace_pokeusr(struct task_struct *child, long regno, long val)
221 {
222         struct pt_regs *regs;
223         regs = task_pt_regs(child);
224
225         switch (regno) {
226                 case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
227                         regs->areg[regno - REG_AR_BASE] = val;
228                         break;
229
230                 case REG_A_BASE ... REG_A_BASE + 15:
231                         regs->areg[regno - REG_A_BASE] = val;
232                         break;
233
234                 case REG_PC:
235                         regs->pc = val;
236                         break;
237
238                 case SYSCALL_NR:
239                         regs->syscall = val;
240                         break;
241
242                 default:
243                         return -EIO;
244         }
245         return 0;
246 }
247
248 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
249 {
250         int ret = -EPERM;
251
252         switch (request) {
253         case PTRACE_PEEKTEXT:   /* read word at location addr. */
254         case PTRACE_PEEKDATA:
255                 ret = generic_ptrace_peekdata(child, addr, data);
256                 break;
257
258         case PTRACE_PEEKUSR:    /* read register specified by addr. */
259                 ret = ptrace_peekusr(child, addr, (void __user *) data);
260                 break;
261
262         case PTRACE_POKETEXT:   /* write the word at location addr. */
263         case PTRACE_POKEDATA:
264                 ret = generic_ptrace_pokedata(child, addr, data);
265                 break;
266
267         case PTRACE_POKEUSR:    /* write register specified by addr. */
268                 ret = ptrace_pokeusr(child, addr, data);
269                 break;
270
271         /* continue and stop at next (return from) syscall */
272
273         case PTRACE_SYSCALL:
274         case PTRACE_CONT: /* restart after signal. */
275         {
276                 ret = -EIO;
277                 if (!valid_signal(data))
278                         break;
279                 if (request == PTRACE_SYSCALL)
280                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
281                 else
282                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
283                 child->exit_code = data;
284                 /* Make sure the single step bit is not set. */
285                 child->ptrace &= ~PT_SINGLESTEP;
286                 wake_up_process(child);
287                 ret = 0;
288                 break;
289         }
290
291         /*
292          * make the child exit.  Best I can do is send it a sigkill.
293          * perhaps it should be put in the status that it wants to
294          * exit.
295          */
296         case PTRACE_KILL:
297                 ret = 0;
298                 if (child->exit_state == EXIT_ZOMBIE)   /* already dead */
299                         break;
300                 child->exit_code = SIGKILL;
301                 child->ptrace &= ~PT_SINGLESTEP;
302                 wake_up_process(child);
303                 break;
304
305         case PTRACE_SINGLESTEP:
306                 ret = -EIO;
307                 if (!valid_signal(data))
308                         break;
309                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
310                 child->ptrace |= PT_SINGLESTEP;
311                 child->exit_code = data;
312                 wake_up_process(child);
313                 ret = 0;
314                 break;
315
316         case PTRACE_GETREGS:
317                 ret = ptrace_getregs(child, (void __user *) data);
318                 break;
319
320         case PTRACE_SETREGS:
321                 ret = ptrace_setregs(child, (void __user *) data);
322                 break;
323
324         case PTRACE_GETXTREGS:
325                 ret = ptrace_getxregs(child, (void __user *) data);
326                 break;
327
328         case PTRACE_SETXTREGS:
329                 ret = ptrace_setxregs(child, (void __user *) data);
330                 break;
331
332         default:
333                 ret = ptrace_request(child, request, addr, data);
334                 break;
335         }
336
337         return ret;
338 }
339
340 void do_syscall_trace(void)
341 {
342         /*
343          * The 0x80 provides a way for the tracing parent to distinguish
344          * between a syscall stop and SIGTRAP delivery
345          */
346         ptrace_notify(SIGTRAP|((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
347
348         /*
349          * this isn't the same as continuing with a signal, but it will do
350          * for normal use.  strace only continues with a signal if the
351          * stopping signal is not SIGTRAP.  -brl
352          */
353         if (current->exit_code) {
354                 send_sig(current->exit_code, current, 1);
355                 current->exit_code = 0;
356         }
357 }
358
359 void do_syscall_trace_enter(struct pt_regs *regs)
360 {
361         if (test_thread_flag(TIF_SYSCALL_TRACE)
362                         && (current->ptrace & PT_PTRACED))
363                 do_syscall_trace();
364
365 #if 0
366         if (unlikely(current->audit_context))
367                 audit_syscall_entry(current, AUDIT_ARCH_XTENSA..);
368 #endif
369 }
370
371 void do_syscall_trace_leave(struct pt_regs *regs)
372 {
373         if ((test_thread_flag(TIF_SYSCALL_TRACE))
374                         && (current->ptrace & PT_PTRACED))
375                 do_syscall_trace();
376 }
377