9d2591423eb7dd0ae987aa5a3529e66ece4549e5
[linux-2.6.git] / arch / ia64 / kernel / ptrace.c
1 /*
2  * Kernel support for the ptrace() and syscall tracing interfaces.
3  *
4  * Copyright (C) 1999-2005 Hewlett-Packard Co
5  *      David Mosberger-Tang <davidm@hpl.hp.com>
6  *
7  * Derived from the x86 and Alpha versions.
8  */
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/mm.h>
13 #include <linux/errno.h>
14 #include <linux/ptrace.h>
15 #include <linux/smp_lock.h>
16 #include <linux/user.h>
17 #include <linux/security.h>
18 #include <linux/audit.h>
19 #include <linux/signal.h>
20
21 #include <asm/pgtable.h>
22 #include <asm/processor.h>
23 #include <asm/ptrace_offsets.h>
24 #include <asm/rse.h>
25 #include <asm/system.h>
26 #include <asm/uaccess.h>
27 #include <asm/unwind.h>
28 #ifdef CONFIG_PERFMON
29 #include <asm/perfmon.h>
30 #endif
31
32 #include "entry.h"
33
34 /*
35  * Bits in the PSR that we allow ptrace() to change:
36  *      be, up, ac, mfl, mfh (the user mask; five bits total)
37  *      db (debug breakpoint fault; one bit)
38  *      id (instruction debug fault disable; one bit)
39  *      dd (data debug fault disable; one bit)
40  *      ri (restart instruction; two bits)
41  *      is (instruction set; one bit)
42  */
43 #define IPSR_MASK (IA64_PSR_UM | IA64_PSR_DB | IA64_PSR_IS      \
44                    | IA64_PSR_ID | IA64_PSR_DD | IA64_PSR_RI)
45
46 #define MASK(nbits)     ((1UL << (nbits)) - 1)  /* mask with NBITS bits set */
47 #define PFM_MASK        MASK(38)
48
49 #define PTRACE_DEBUG    0
50
51 #if PTRACE_DEBUG
52 # define dprintk(format...)     printk(format)
53 # define inline
54 #else
55 # define dprintk(format...)
56 #endif
57
58 /* Return TRUE if PT was created due to kernel-entry via a system-call.  */
59
60 static inline int
61 in_syscall (struct pt_regs *pt)
62 {
63         return (long) pt->cr_ifs >= 0;
64 }
65
66 /*
67  * Collect the NaT bits for r1-r31 from scratch_unat and return a NaT
68  * bitset where bit i is set iff the NaT bit of register i is set.
69  */
70 unsigned long
71 ia64_get_scratch_nat_bits (struct pt_regs *pt, unsigned long scratch_unat)
72 {
73 #       define GET_BITS(first, last, unat)                              \
74         ({                                                              \
75                 unsigned long bit = ia64_unat_pos(&pt->r##first);       \
76                 unsigned long nbits = (last - first + 1);               \
77                 unsigned long mask = MASK(nbits) << first;              \
78                 unsigned long dist;                                     \
79                 if (bit < first)                                        \
80                         dist = 64 + bit - first;                        \
81                 else                                                    \
82                         dist = bit - first;                             \
83                 ia64_rotr(unat, dist) & mask;                           \
84         })
85         unsigned long val;
86
87         /*
88          * Registers that are stored consecutively in struct pt_regs
89          * can be handled in parallel.  If the register order in
90          * struct_pt_regs changes, this code MUST be updated.
91          */
92         val  = GET_BITS( 1,  1, scratch_unat);
93         val |= GET_BITS( 2,  3, scratch_unat);
94         val |= GET_BITS(12, 13, scratch_unat);
95         val |= GET_BITS(14, 14, scratch_unat);
96         val |= GET_BITS(15, 15, scratch_unat);
97         val |= GET_BITS( 8, 11, scratch_unat);
98         val |= GET_BITS(16, 31, scratch_unat);
99         return val;
100
101 #       undef GET_BITS
102 }
103
104 /*
105  * Set the NaT bits for the scratch registers according to NAT and
106  * return the resulting unat (assuming the scratch registers are
107  * stored in PT).
108  */
109 unsigned long
110 ia64_put_scratch_nat_bits (struct pt_regs *pt, unsigned long nat)
111 {
112 #       define PUT_BITS(first, last, nat)                               \
113         ({                                                              \
114                 unsigned long bit = ia64_unat_pos(&pt->r##first);       \
115                 unsigned long nbits = (last - first + 1);               \
116                 unsigned long mask = MASK(nbits) << first;              \
117                 long dist;                                              \
118                 if (bit < first)                                        \
119                         dist = 64 + bit - first;                        \
120                 else                                                    \
121                         dist = bit - first;                             \
122                 ia64_rotl(nat & mask, dist);                            \
123         })
124         unsigned long scratch_unat;
125
126         /*
127          * Registers that are stored consecutively in struct pt_regs
128          * can be handled in parallel.  If the register order in
129          * struct_pt_regs changes, this code MUST be updated.
130          */
131         scratch_unat  = PUT_BITS( 1,  1, nat);
132         scratch_unat |= PUT_BITS( 2,  3, nat);
133         scratch_unat |= PUT_BITS(12, 13, nat);
134         scratch_unat |= PUT_BITS(14, 14, nat);
135         scratch_unat |= PUT_BITS(15, 15, nat);
136         scratch_unat |= PUT_BITS( 8, 11, nat);
137         scratch_unat |= PUT_BITS(16, 31, nat);
138
139         return scratch_unat;
140
141 #       undef PUT_BITS
142 }
143
144 #define IA64_MLX_TEMPLATE       0x2
145 #define IA64_MOVL_OPCODE        6
146
147 void
148 ia64_increment_ip (struct pt_regs *regs)
149 {
150         unsigned long w0, ri = ia64_psr(regs)->ri + 1;
151
152         if (ri > 2) {
153                 ri = 0;
154                 regs->cr_iip += 16;
155         } else if (ri == 2) {
156                 get_user(w0, (char __user *) regs->cr_iip + 0);
157                 if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) {
158                         /*
159                          * rfi'ing to slot 2 of an MLX bundle causes
160                          * an illegal operation fault.  We don't want
161                          * that to happen...
162                          */
163                         ri = 0;
164                         regs->cr_iip += 16;
165                 }
166         }
167         ia64_psr(regs)->ri = ri;
168 }
169
170 void
171 ia64_decrement_ip (struct pt_regs *regs)
172 {
173         unsigned long w0, ri = ia64_psr(regs)->ri - 1;
174
175         if (ia64_psr(regs)->ri == 0) {
176                 regs->cr_iip -= 16;
177                 ri = 2;
178                 get_user(w0, (char __user *) regs->cr_iip + 0);
179                 if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) {
180                         /*
181                          * rfi'ing to slot 2 of an MLX bundle causes
182                          * an illegal operation fault.  We don't want
183                          * that to happen...
184                          */
185                         ri = 1;
186                 }
187         }
188         ia64_psr(regs)->ri = ri;
189 }
190
191 /*
192  * This routine is used to read an rnat bits that are stored on the
193  * kernel backing store.  Since, in general, the alignment of the user
194  * and kernel are different, this is not completely trivial.  In
195  * essence, we need to construct the user RNAT based on up to two
196  * kernel RNAT values and/or the RNAT value saved in the child's
197  * pt_regs.
198  *
199  * user rbs
200  *
201  * +--------+ <-- lowest address
202  * | slot62 |
203  * +--------+
204  * |  rnat  | 0x....1f8
205  * +--------+
206  * | slot00 | \
207  * +--------+ |
208  * | slot01 | > child_regs->ar_rnat
209  * +--------+ |
210  * | slot02 | /                         kernel rbs
211  * +--------+                           +--------+
212  *          <- child_regs->ar_bspstore  | slot61 | <-- krbs
213  * +- - - - +                           +--------+
214  *                                      | slot62 |
215  * +- - - - +                           +--------+
216  *                                      |  rnat  |
217  * +- - - - +                           +--------+
218  *   vrnat                              | slot00 |
219  * +- - - - +                           +--------+
220  *                                      =        =
221  *                                      +--------+
222  *                                      | slot00 | \
223  *                                      +--------+ |
224  *                                      | slot01 | > child_stack->ar_rnat
225  *                                      +--------+ |
226  *                                      | slot02 | /
227  *                                      +--------+
228  *                                                <--- child_stack->ar_bspstore
229  *
230  * The way to think of this code is as follows: bit 0 in the user rnat
231  * corresponds to some bit N (0 <= N <= 62) in one of the kernel rnat
232  * value.  The kernel rnat value holding this bit is stored in
233  * variable rnat0.  rnat1 is loaded with the kernel rnat value that
234  * form the upper bits of the user rnat value.
235  *
236  * Boundary cases:
237  *
238  * o when reading the rnat "below" the first rnat slot on the kernel
239  *   backing store, rnat0/rnat1 are set to 0 and the low order bits are
240  *   merged in from pt->ar_rnat.
241  *
242  * o when reading the rnat "above" the last rnat slot on the kernel
243  *   backing store, rnat0/rnat1 gets its value from sw->ar_rnat.
244  */
245 static unsigned long
246 get_rnat (struct task_struct *task, struct switch_stack *sw,
247           unsigned long *krbs, unsigned long *urnat_addr,
248           unsigned long *urbs_end)
249 {
250         unsigned long rnat0 = 0, rnat1 = 0, urnat = 0, *slot0_kaddr;
251         unsigned long umask = 0, mask, m;
252         unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift;
253         long num_regs, nbits;
254         struct pt_regs *pt;
255
256         pt = task_pt_regs(task);
257         kbsp = (unsigned long *) sw->ar_bspstore;
258         ubspstore = (unsigned long *) pt->ar_bspstore;
259
260         if (urbs_end < urnat_addr)
261                 nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_end);
262         else
263                 nbits = 63;
264         mask = MASK(nbits);
265         /*
266          * First, figure out which bit number slot 0 in user-land maps
267          * to in the kernel rnat.  Do this by figuring out how many
268          * register slots we're beyond the user's backingstore and
269          * then computing the equivalent address in kernel space.
270          */
271         num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1);
272         slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs);
273         shift = ia64_rse_slot_num(slot0_kaddr);
274         rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr);
275         rnat0_kaddr = rnat1_kaddr - 64;
276
277         if (ubspstore + 63 > urnat_addr) {
278                 /* some bits need to be merged in from pt->ar_rnat */
279                 umask = MASK(ia64_rse_slot_num(ubspstore)) & mask;
280                 urnat = (pt->ar_rnat & umask);
281                 mask &= ~umask;
282                 if (!mask)
283                         return urnat;
284         }
285
286         m = mask << shift;
287         if (rnat0_kaddr >= kbsp)
288                 rnat0 = sw->ar_rnat;
289         else if (rnat0_kaddr > krbs)
290                 rnat0 = *rnat0_kaddr;
291         urnat |= (rnat0 & m) >> shift;
292
293         m = mask >> (63 - shift);
294         if (rnat1_kaddr >= kbsp)
295                 rnat1 = sw->ar_rnat;
296         else if (rnat1_kaddr > krbs)
297                 rnat1 = *rnat1_kaddr;
298         urnat |= (rnat1 & m) << (63 - shift);
299         return urnat;
300 }
301
302 /*
303  * The reverse of get_rnat.
304  */
305 static void
306 put_rnat (struct task_struct *task, struct switch_stack *sw,
307           unsigned long *krbs, unsigned long *urnat_addr, unsigned long urnat,
308           unsigned long *urbs_end)
309 {
310         unsigned long rnat0 = 0, rnat1 = 0, *slot0_kaddr, umask = 0, mask, m;
311         unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift;
312         long num_regs, nbits;
313         struct pt_regs *pt;
314         unsigned long cfm, *urbs_kargs;
315
316         pt = task_pt_regs(task);
317         kbsp = (unsigned long *) sw->ar_bspstore;
318         ubspstore = (unsigned long *) pt->ar_bspstore;
319
320         urbs_kargs = urbs_end;
321         if (in_syscall(pt)) {
322                 /*
323                  * If entered via syscall, don't allow user to set rnat bits
324                  * for syscall args.
325                  */
326                 cfm = pt->cr_ifs;
327                 urbs_kargs = ia64_rse_skip_regs(urbs_end, -(cfm & 0x7f));
328         }
329
330         if (urbs_kargs >= urnat_addr)
331                 nbits = 63;
332         else {
333                 if ((urnat_addr - 63) >= urbs_kargs)
334                         return;
335                 nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_kargs);
336         }
337         mask = MASK(nbits);
338
339         /*
340          * First, figure out which bit number slot 0 in user-land maps
341          * to in the kernel rnat.  Do this by figuring out how many
342          * register slots we're beyond the user's backingstore and
343          * then computing the equivalent address in kernel space.
344          */
345         num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1);
346         slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs);
347         shift = ia64_rse_slot_num(slot0_kaddr);
348         rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr);
349         rnat0_kaddr = rnat1_kaddr - 64;
350
351         if (ubspstore + 63 > urnat_addr) {
352                 /* some bits need to be place in pt->ar_rnat: */
353                 umask = MASK(ia64_rse_slot_num(ubspstore)) & mask;
354                 pt->ar_rnat = (pt->ar_rnat & ~umask) | (urnat & umask);
355                 mask &= ~umask;
356                 if (!mask)
357                         return;
358         }
359         /*
360          * Note: Section 11.1 of the EAS guarantees that bit 63 of an
361          * rnat slot is ignored. so we don't have to clear it here.
362          */
363         rnat0 = (urnat << shift);
364         m = mask << shift;
365         if (rnat0_kaddr >= kbsp)
366                 sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat0 & m);
367         else if (rnat0_kaddr > krbs)
368                 *rnat0_kaddr = ((*rnat0_kaddr & ~m) | (rnat0 & m));
369
370         rnat1 = (urnat >> (63 - shift));
371         m = mask >> (63 - shift);
372         if (rnat1_kaddr >= kbsp)
373                 sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat1 & m);
374         else if (rnat1_kaddr > krbs)
375                 *rnat1_kaddr = ((*rnat1_kaddr & ~m) | (rnat1 & m));
376 }
377
378 static inline int
379 on_kernel_rbs (unsigned long addr, unsigned long bspstore,
380                unsigned long urbs_end)
381 {
382         unsigned long *rnat_addr = ia64_rse_rnat_addr((unsigned long *)
383                                                       urbs_end);
384         return (addr >= bspstore && addr <= (unsigned long) rnat_addr);
385 }
386
387 /*
388  * Read a word from the user-level backing store of task CHILD.  ADDR
389  * is the user-level address to read the word from, VAL a pointer to
390  * the return value, and USER_BSP gives the end of the user-level
391  * backing store (i.e., it's the address that would be in ar.bsp after
392  * the user executed a "cover" instruction).
393  *
394  * This routine takes care of accessing the kernel register backing
395  * store for those registers that got spilled there.  It also takes
396  * care of calculating the appropriate RNaT collection words.
397  */
398 long
399 ia64_peek (struct task_struct *child, struct switch_stack *child_stack,
400            unsigned long user_rbs_end, unsigned long addr, long *val)
401 {
402         unsigned long *bspstore, *krbs, regnum, *laddr, *urbs_end, *rnat_addr;
403         struct pt_regs *child_regs;
404         size_t copied;
405         long ret;
406
407         urbs_end = (long *) user_rbs_end;
408         laddr = (unsigned long *) addr;
409         child_regs = task_pt_regs(child);
410         bspstore = (unsigned long *) child_regs->ar_bspstore;
411         krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
412         if (on_kernel_rbs(addr, (unsigned long) bspstore,
413                           (unsigned long) urbs_end))
414         {
415                 /*
416                  * Attempt to read the RBS in an area that's actually
417                  * on the kernel RBS => read the corresponding bits in
418                  * the kernel RBS.
419                  */
420                 rnat_addr = ia64_rse_rnat_addr(laddr);
421                 ret = get_rnat(child, child_stack, krbs, rnat_addr, urbs_end);
422
423                 if (laddr == rnat_addr) {
424                         /* return NaT collection word itself */
425                         *val = ret;
426                         return 0;
427                 }
428
429                 if (((1UL << ia64_rse_slot_num(laddr)) & ret) != 0) {
430                         /*
431                          * It is implementation dependent whether the
432                          * data portion of a NaT value gets saved on a
433                          * st8.spill or RSE spill (e.g., see EAS 2.6,
434                          * 4.4.4.6 Register Spill and Fill).  To get
435                          * consistent behavior across all possible
436                          * IA-64 implementations, we return zero in
437                          * this case.
438                          */
439                         *val = 0;
440                         return 0;
441                 }
442
443                 if (laddr < urbs_end) {
444                         /*
445                          * The desired word is on the kernel RBS and
446                          * is not a NaT.
447                          */
448                         regnum = ia64_rse_num_regs(bspstore, laddr);
449                         *val = *ia64_rse_skip_regs(krbs, regnum);
450                         return 0;
451                 }
452         }
453         copied = access_process_vm(child, addr, &ret, sizeof(ret), 0);
454         if (copied != sizeof(ret))
455                 return -EIO;
456         *val = ret;
457         return 0;
458 }
459
460 long
461 ia64_poke (struct task_struct *child, struct switch_stack *child_stack,
462            unsigned long user_rbs_end, unsigned long addr, long val)
463 {
464         unsigned long *bspstore, *krbs, regnum, *laddr;
465         unsigned long *urbs_end = (long *) user_rbs_end;
466         struct pt_regs *child_regs;
467
468         laddr = (unsigned long *) addr;
469         child_regs = task_pt_regs(child);
470         bspstore = (unsigned long *) child_regs->ar_bspstore;
471         krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
472         if (on_kernel_rbs(addr, (unsigned long) bspstore,
473                           (unsigned long) urbs_end))
474         {
475                 /*
476                  * Attempt to write the RBS in an area that's actually
477                  * on the kernel RBS => write the corresponding bits
478                  * in the kernel RBS.
479                  */
480                 if (ia64_rse_is_rnat_slot(laddr))
481                         put_rnat(child, child_stack, krbs, laddr, val,
482                                  urbs_end);
483                 else {
484                         if (laddr < urbs_end) {
485                                 regnum = ia64_rse_num_regs(bspstore, laddr);
486                                 *ia64_rse_skip_regs(krbs, regnum) = val;
487                         }
488                 }
489         } else if (access_process_vm(child, addr, &val, sizeof(val), 1)
490                    != sizeof(val))
491                 return -EIO;
492         return 0;
493 }
494
495 /*
496  * Calculate the address of the end of the user-level register backing
497  * store.  This is the address that would have been stored in ar.bsp
498  * if the user had executed a "cover" instruction right before
499  * entering the kernel.  If CFMP is not NULL, it is used to return the
500  * "current frame mask" that was active at the time the kernel was
501  * entered.
502  */
503 unsigned long
504 ia64_get_user_rbs_end (struct task_struct *child, struct pt_regs *pt,
505                        unsigned long *cfmp)
506 {
507         unsigned long *krbs, *bspstore, cfm = pt->cr_ifs;
508         long ndirty;
509
510         krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
511         bspstore = (unsigned long *) pt->ar_bspstore;
512         ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19));
513
514         if (in_syscall(pt))
515                 ndirty += (cfm & 0x7f);
516         else
517                 cfm &= ~(1UL << 63);    /* clear valid bit */
518
519         if (cfmp)
520                 *cfmp = cfm;
521         return (unsigned long) ia64_rse_skip_regs(bspstore, ndirty);
522 }
523
524 /*
525  * Synchronize (i.e, write) the RSE backing store living in kernel
526  * space to the VM of the CHILD task.  SW and PT are the pointers to
527  * the switch_stack and pt_regs structures, respectively.
528  * USER_RBS_END is the user-level address at which the backing store
529  * ends.
530  */
531 long
532 ia64_sync_user_rbs (struct task_struct *child, struct switch_stack *sw,
533                     unsigned long user_rbs_start, unsigned long user_rbs_end)
534 {
535         unsigned long addr, val;
536         long ret;
537
538         /* now copy word for word from kernel rbs to user rbs: */
539         for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
540                 ret = ia64_peek(child, sw, user_rbs_end, addr, &val);
541                 if (ret < 0)
542                         return ret;
543                 if (access_process_vm(child, addr, &val, sizeof(val), 1)
544                     != sizeof(val))
545                         return -EIO;
546         }
547         return 0;
548 }
549
550 static long
551 ia64_sync_kernel_rbs (struct task_struct *child, struct switch_stack *sw,
552                 unsigned long user_rbs_start, unsigned long user_rbs_end)
553 {
554         unsigned long addr, val;
555         long ret;
556
557         /* now copy word for word from user rbs to kernel rbs: */
558         for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
559                 if (access_process_vm(child, addr, &val, sizeof(val), 0)
560                                 != sizeof(val))
561                         return -EIO;
562
563                 ret = ia64_poke(child, sw, user_rbs_end, addr, val);
564                 if (ret < 0)
565                         return ret;
566         }
567         return 0;
568 }
569
570 typedef long (*syncfunc_t)(struct task_struct *, struct switch_stack *,
571                             unsigned long, unsigned long);
572
573 static void do_sync_rbs(struct unw_frame_info *info, void *arg)
574 {
575         struct pt_regs *pt;
576         unsigned long urbs_end;
577         syncfunc_t fn = arg;
578
579         if (unw_unwind_to_user(info) < 0)
580                 return;
581         pt = task_pt_regs(info->task);
582         urbs_end = ia64_get_user_rbs_end(info->task, pt, NULL);
583
584         fn(info->task, info->sw, pt->ar_bspstore, urbs_end);
585 }
586
587 /*
588  * when a thread is stopped (ptraced), debugger might change thread's user
589  * stack (change memory directly), and we must avoid the RSE stored in kernel
590  * to override user stack (user space's RSE is newer than kernel's in the
591  * case). To workaround the issue, we copy kernel RSE to user RSE before the
592  * task is stopped, so user RSE has updated data.  we then copy user RSE to
593  * kernel after the task is resummed from traced stop and kernel will use the
594  * newer RSE to return to user. TIF_RESTORE_RSE is the flag to indicate we need
595  * synchronize user RSE to kernel.
596  */
597 void ia64_ptrace_stop(void)
598 {
599         if (test_and_set_tsk_thread_flag(current, TIF_RESTORE_RSE))
600                 return;
601         tsk_set_notify_resume(current);
602         unw_init_running(do_sync_rbs, ia64_sync_user_rbs);
603 }
604
605 /*
606  * This is called to read back the register backing store.
607  */
608 void ia64_sync_krbs(void)
609 {
610         clear_tsk_thread_flag(current, TIF_RESTORE_RSE);
611         tsk_clear_notify_resume(current);
612
613         unw_init_running(do_sync_rbs, ia64_sync_kernel_rbs);
614 }
615
616 /*
617  * After PTRACE_ATTACH, a thread's register backing store area in user
618  * space is assumed to contain correct data whenever the thread is
619  * stopped.  arch_ptrace_stop takes care of this on tracing stops.
620  * But if the child was already stopped for job control when we attach
621  * to it, then it might not ever get into ptrace_stop by the time we
622  * want to examine the user memory containing the RBS.
623  */
624 void
625 ptrace_attach_sync_user_rbs (struct task_struct *child)
626 {
627         int stopped = 0;
628         struct unw_frame_info info;
629
630         /*
631          * If the child is in TASK_STOPPED, we need to change that to
632          * TASK_TRACED momentarily while we operate on it.  This ensures
633          * that the child won't be woken up and return to user mode while
634          * we are doing the sync.  (It can only be woken up for SIGKILL.)
635          */
636
637         read_lock(&tasklist_lock);
638         if (child->signal) {
639                 spin_lock_irq(&child->sighand->siglock);
640                 if (child->state == TASK_STOPPED &&
641                     !test_and_set_tsk_thread_flag(child, TIF_RESTORE_RSE)) {
642                         tsk_set_notify_resume(child);
643
644                         child->state = TASK_TRACED;
645                         stopped = 1;
646                 }
647                 spin_unlock_irq(&child->sighand->siglock);
648         }
649         read_unlock(&tasklist_lock);
650
651         if (!stopped)
652                 return;
653
654         unw_init_from_blocked_task(&info, child);
655         do_sync_rbs(&info, ia64_sync_user_rbs);
656
657         /*
658          * Now move the child back into TASK_STOPPED if it should be in a
659          * job control stop, so that SIGCONT can be used to wake it up.
660          */
661         read_lock(&tasklist_lock);
662         if (child->signal) {
663                 spin_lock_irq(&child->sighand->siglock);
664                 if (child->state == TASK_TRACED &&
665                     (child->signal->flags & SIGNAL_STOP_STOPPED)) {
666                         child->state = TASK_STOPPED;
667                 }
668                 spin_unlock_irq(&child->sighand->siglock);
669         }
670         read_unlock(&tasklist_lock);
671 }
672
673 static inline int
674 thread_matches (struct task_struct *thread, unsigned long addr)
675 {
676         unsigned long thread_rbs_end;
677         struct pt_regs *thread_regs;
678
679         if (ptrace_check_attach(thread, 0) < 0)
680                 /*
681                  * If the thread is not in an attachable state, we'll
682                  * ignore it.  The net effect is that if ADDR happens
683                  * to overlap with the portion of the thread's
684                  * register backing store that is currently residing
685                  * on the thread's kernel stack, then ptrace() may end
686                  * up accessing a stale value.  But if the thread
687                  * isn't stopped, that's a problem anyhow, so we're
688                  * doing as well as we can...
689                  */
690                 return 0;
691
692         thread_regs = task_pt_regs(thread);
693         thread_rbs_end = ia64_get_user_rbs_end(thread, thread_regs, NULL);
694         if (!on_kernel_rbs(addr, thread_regs->ar_bspstore, thread_rbs_end))
695                 return 0;
696
697         return 1;       /* looks like we've got a winner */
698 }
699
700 /*
701  * GDB apparently wants to be able to read the register-backing store
702  * of any thread when attached to a given process.  If we are peeking
703  * or poking an address that happens to reside in the kernel-backing
704  * store of another thread, we need to attach to that thread, because
705  * otherwise we end up accessing stale data.
706  *
707  * task_list_lock must be read-locked before calling this routine!
708  */
709 static struct task_struct *
710 find_thread_for_addr (struct task_struct *child, unsigned long addr)
711 {
712         struct task_struct *p;
713         struct mm_struct *mm;
714         struct list_head *this, *next;
715         int mm_users;
716
717         if (!(mm = get_task_mm(child)))
718                 return child;
719
720         /* -1 because of our get_task_mm(): */
721         mm_users = atomic_read(&mm->mm_users) - 1;
722         if (mm_users <= 1)
723                 goto out;               /* not multi-threaded */
724
725         /*
726          * Traverse the current process' children list.  Every task that
727          * one attaches to becomes a child.  And it is only attached children
728          * of the debugger that are of interest (ptrace_check_attach checks
729          * for this).
730          */
731         list_for_each_safe(this, next, &current->children) {
732                 p = list_entry(this, struct task_struct, sibling);
733                 if (p->tgid != child->tgid)
734                         continue;
735                 if (thread_matches(p, addr)) {
736                         child = p;
737                         goto out;
738                 }
739         }
740
741   out:
742         mmput(mm);
743         return child;
744 }
745
746 /*
747  * Write f32-f127 back to task->thread.fph if it has been modified.
748  */
749 inline void
750 ia64_flush_fph (struct task_struct *task)
751 {
752         struct ia64_psr *psr = ia64_psr(task_pt_regs(task));
753
754         /*
755          * Prevent migrating this task while
756          * we're fiddling with the FPU state
757          */
758         preempt_disable();
759         if (ia64_is_local_fpu_owner(task) && psr->mfh) {
760                 psr->mfh = 0;
761                 task->thread.flags |= IA64_THREAD_FPH_VALID;
762                 ia64_save_fpu(&task->thread.fph[0]);
763         }
764         preempt_enable();
765 }
766
767 /*
768  * Sync the fph state of the task so that it can be manipulated
769  * through thread.fph.  If necessary, f32-f127 are written back to
770  * thread.fph or, if the fph state hasn't been used before, thread.fph
771  * is cleared to zeroes.  Also, access to f32-f127 is disabled to
772  * ensure that the task picks up the state from thread.fph when it
773  * executes again.
774  */
775 void
776 ia64_sync_fph (struct task_struct *task)
777 {
778         struct ia64_psr *psr = ia64_psr(task_pt_regs(task));
779
780         ia64_flush_fph(task);
781         if (!(task->thread.flags & IA64_THREAD_FPH_VALID)) {
782                 task->thread.flags |= IA64_THREAD_FPH_VALID;
783                 memset(&task->thread.fph, 0, sizeof(task->thread.fph));
784         }
785         ia64_drop_fpu(task);
786         psr->dfh = 1;
787 }
788
789 static int
790 access_fr (struct unw_frame_info *info, int regnum, int hi,
791            unsigned long *data, int write_access)
792 {
793         struct ia64_fpreg fpval;
794         int ret;
795
796         ret = unw_get_fr(info, regnum, &fpval);
797         if (ret < 0)
798                 return ret;
799
800         if (write_access) {
801                 fpval.u.bits[hi] = *data;
802                 ret = unw_set_fr(info, regnum, fpval);
803         } else
804                 *data = fpval.u.bits[hi];
805         return ret;
806 }
807
808 /*
809  * Change the machine-state of CHILD such that it will return via the normal
810  * kernel exit-path, rather than the syscall-exit path.
811  */
812 static void
813 convert_to_non_syscall (struct task_struct *child, struct pt_regs  *pt,
814                         unsigned long cfm)
815 {
816         struct unw_frame_info info, prev_info;
817         unsigned long ip, sp, pr;
818
819         unw_init_from_blocked_task(&info, child);
820         while (1) {
821                 prev_info = info;
822                 if (unw_unwind(&info) < 0)
823                         return;
824
825                 unw_get_sp(&info, &sp);
826                 if ((long)((unsigned long)child + IA64_STK_OFFSET - sp)
827                     < IA64_PT_REGS_SIZE) {
828                         dprintk("ptrace.%s: ran off the top of the kernel "
829                                 "stack\n", __FUNCTION__);
830                         return;
831                 }
832                 if (unw_get_pr (&prev_info, &pr) < 0) {
833                         unw_get_rp(&prev_info, &ip);
834                         dprintk("ptrace.%s: failed to read "
835                                 "predicate register (ip=0x%lx)\n",
836                                 __FUNCTION__, ip);
837                         return;
838                 }
839                 if (unw_is_intr_frame(&info)
840                     && (pr & (1UL << PRED_USER_STACK)))
841                         break;
842         }
843
844         /*
845          * Note: at the time of this call, the target task is blocked
846          * in notify_resume_user() and by clearling PRED_LEAVE_SYSCALL
847          * (aka, "pLvSys") we redirect execution from
848          * .work_pending_syscall_end to .work_processed_kernel.
849          */
850         unw_get_pr(&prev_info, &pr);
851         pr &= ~((1UL << PRED_SYSCALL) | (1UL << PRED_LEAVE_SYSCALL));
852         pr |=  (1UL << PRED_NON_SYSCALL);
853         unw_set_pr(&prev_info, pr);
854
855         pt->cr_ifs = (1UL << 63) | cfm;
856         /*
857          * Clear the memory that is NOT written on syscall-entry to
858          * ensure we do not leak kernel-state to user when execution
859          * resumes.
860          */
861         pt->r2 = 0;
862         pt->r3 = 0;
863         pt->r14 = 0;
864         memset(&pt->r16, 0, 16*8);      /* clear r16-r31 */
865         memset(&pt->f6, 0, 6*16);       /* clear f6-f11 */
866         pt->b7 = 0;
867         pt->ar_ccv = 0;
868         pt->ar_csd = 0;
869         pt->ar_ssd = 0;
870 }
871
872 static int
873 access_nat_bits (struct task_struct *child, struct pt_regs *pt,
874                  struct unw_frame_info *info,
875                  unsigned long *data, int write_access)
876 {
877         unsigned long regnum, nat_bits, scratch_unat, dummy = 0;
878         char nat = 0;
879
880         if (write_access) {
881                 nat_bits = *data;
882                 scratch_unat = ia64_put_scratch_nat_bits(pt, nat_bits);
883                 if (unw_set_ar(info, UNW_AR_UNAT, scratch_unat) < 0) {
884                         dprintk("ptrace: failed to set ar.unat\n");
885                         return -1;
886                 }
887                 for (regnum = 4; regnum <= 7; ++regnum) {
888                         unw_get_gr(info, regnum, &dummy, &nat);
889                         unw_set_gr(info, regnum, dummy,
890                                    (nat_bits >> regnum) & 1);
891                 }
892         } else {
893                 if (unw_get_ar(info, UNW_AR_UNAT, &scratch_unat) < 0) {
894                         dprintk("ptrace: failed to read ar.unat\n");
895                         return -1;
896                 }
897                 nat_bits = ia64_get_scratch_nat_bits(pt, scratch_unat);
898                 for (regnum = 4; regnum <= 7; ++regnum) {
899                         unw_get_gr(info, regnum, &dummy, &nat);
900                         nat_bits |= (nat != 0) << regnum;
901                 }
902                 *data = nat_bits;
903         }
904         return 0;
905 }
906
907 static int
908 access_uarea (struct task_struct *child, unsigned long addr,
909               unsigned long *data, int write_access)
910 {
911         unsigned long *ptr, regnum, urbs_end, cfm;
912         struct switch_stack *sw;
913         struct pt_regs *pt;
914 #       define pt_reg_addr(pt, reg)     ((void *)                           \
915                                          ((unsigned long) (pt)              \
916                                           + offsetof(struct pt_regs, reg)))
917
918
919         pt = task_pt_regs(child);
920         sw = (struct switch_stack *) (child->thread.ksp + 16);
921
922         if ((addr & 0x7) != 0) {
923                 dprintk("ptrace: unaligned register address 0x%lx\n", addr);
924                 return -1;
925         }
926
927         if (addr < PT_F127 + 16) {
928                 /* accessing fph */
929                 if (write_access)
930                         ia64_sync_fph(child);
931                 else
932                         ia64_flush_fph(child);
933                 ptr = (unsigned long *)
934                         ((unsigned long) &child->thread.fph + addr);
935         } else if ((addr >= PT_F10) && (addr < PT_F11 + 16)) {
936                 /* scratch registers untouched by kernel (saved in pt_regs) */
937                 ptr = pt_reg_addr(pt, f10) + (addr - PT_F10);
938         } else if (addr >= PT_F12 && addr < PT_F15 + 16) {
939                 /*
940                  * Scratch registers untouched by kernel (saved in
941                  * switch_stack).
942                  */
943                 ptr = (unsigned long *) ((long) sw
944                                          + (addr - PT_NAT_BITS - 32));
945         } else if (addr < PT_AR_LC + 8) {
946                 /* preserved state: */
947                 struct unw_frame_info info;
948                 char nat = 0;
949                 int ret;
950
951                 unw_init_from_blocked_task(&info, child);
952                 if (unw_unwind_to_user(&info) < 0)
953                         return -1;
954
955                 switch (addr) {
956                       case PT_NAT_BITS:
957                         return access_nat_bits(child, pt, &info,
958                                                data, write_access);
959
960                       case PT_R4: case PT_R5: case PT_R6: case PT_R7:
961                         if (write_access) {
962                                 /* read NaT bit first: */
963                                 unsigned long dummy;
964
965                                 ret = unw_get_gr(&info, (addr - PT_R4)/8 + 4,
966                                                  &dummy, &nat);
967                                 if (ret < 0)
968                                         return ret;
969                         }
970                         return unw_access_gr(&info, (addr - PT_R4)/8 + 4, data,
971                                              &nat, write_access);
972
973                       case PT_B1: case PT_B2: case PT_B3:
974                       case PT_B4: case PT_B5:
975                         return unw_access_br(&info, (addr - PT_B1)/8 + 1, data,
976                                              write_access);
977
978                       case PT_AR_EC:
979                         return unw_access_ar(&info, UNW_AR_EC, data,
980                                              write_access);
981
982                       case PT_AR_LC:
983                         return unw_access_ar(&info, UNW_AR_LC, data,
984                                              write_access);
985
986                       default:
987                         if (addr >= PT_F2 && addr < PT_F5 + 16)
988                                 return access_fr(&info, (addr - PT_F2)/16 + 2,
989                                                  (addr & 8) != 0, data,
990                                                  write_access);
991                         else if (addr >= PT_F16 && addr < PT_F31 + 16)
992                                 return access_fr(&info,
993                                                  (addr - PT_F16)/16 + 16,
994                                                  (addr & 8) != 0,
995                                                  data, write_access);
996                         else {
997                                 dprintk("ptrace: rejecting access to register "
998                                         "address 0x%lx\n", addr);
999                                 return -1;
1000                         }
1001                 }
1002         } else if (addr < PT_F9+16) {
1003                 /* scratch state */
1004                 switch (addr) {
1005                       case PT_AR_BSP:
1006                         /*
1007                          * By convention, we use PT_AR_BSP to refer to
1008                          * the end of the user-level backing store.
1009                          * Use ia64_rse_skip_regs(PT_AR_BSP, -CFM.sof)
1010                          * to get the real value of ar.bsp at the time
1011                          * the kernel was entered.
1012                          *
1013                          * Furthermore, when changing the contents of
1014                          * PT_AR_BSP (or PT_CFM) we MUST copy any
1015                          * users-level stacked registers that are
1016                          * stored on the kernel stack back to
1017                          * user-space because otherwise, we might end
1018                          * up clobbering kernel stacked registers.
1019                          * Also, if this happens while the task is
1020                          * blocked in a system call, which convert the
1021                          * state such that the non-system-call exit
1022                          * path is used.  This ensures that the proper
1023                          * state will be picked up when resuming
1024                          * execution.  However, it *also* means that
1025                          * once we write PT_AR_BSP/PT_CFM, it won't be
1026                          * possible to modify the syscall arguments of
1027                          * the pending system call any longer.  This
1028                          * shouldn't be an issue because modifying
1029                          * PT_AR_BSP/PT_CFM generally implies that
1030                          * we're either abandoning the pending system
1031                          * call or that we defer it's re-execution
1032                          * (e.g., due to GDB doing an inferior
1033                          * function call).
1034                          */
1035                         urbs_end = ia64_get_user_rbs_end(child, pt, &cfm);
1036                         if (write_access) {
1037                                 if (*data != urbs_end) {
1038                                         if (ia64_sync_user_rbs(child, sw,
1039                                                                pt->ar_bspstore,
1040                                                                urbs_end) < 0)
1041                                                 return -1;
1042                                         if (in_syscall(pt))
1043                                                 convert_to_non_syscall(child,
1044                                                                        pt,
1045                                                                        cfm);
1046                                         /*
1047                                          * Simulate user-level write
1048                                          * of ar.bsp:
1049                                          */
1050                                         pt->loadrs = 0;
1051                                         pt->ar_bspstore = *data;
1052                                 }
1053                         } else
1054                                 *data = urbs_end;
1055                         return 0;
1056
1057                       case PT_CFM:
1058                         urbs_end = ia64_get_user_rbs_end(child, pt, &cfm);
1059                         if (write_access) {
1060                                 if (((cfm ^ *data) & PFM_MASK) != 0) {
1061                                         if (ia64_sync_user_rbs(child, sw,
1062                                                                pt->ar_bspstore,
1063                                                                urbs_end) < 0)
1064                                                 return -1;
1065                                         if (in_syscall(pt))
1066                                                 convert_to_non_syscall(child,
1067                                                                        pt,
1068                                                                        cfm);
1069                                         pt->cr_ifs = ((pt->cr_ifs & ~PFM_MASK)
1070                                                       | (*data & PFM_MASK));
1071                                 }
1072                         } else
1073                                 *data = cfm;
1074                         return 0;
1075
1076                       case PT_CR_IPSR:
1077                         if (write_access) {
1078                                 unsigned long tmp = *data;
1079                                 /* psr.ri==3 is a reserved value: SDM 2:25 */
1080                                 if ((tmp & IA64_PSR_RI) == IA64_PSR_RI)
1081                                         tmp &= ~IA64_PSR_RI;
1082                                 pt->cr_ipsr = ((tmp & IPSR_MASK)
1083                                                | (pt->cr_ipsr & ~IPSR_MASK));
1084                         } else
1085                                 *data = (pt->cr_ipsr & IPSR_MASK);
1086                         return 0;
1087
1088                       case PT_AR_RSC:
1089                         if (write_access)
1090                                 pt->ar_rsc = *data | (3 << 2); /* force PL3 */
1091                         else
1092                                 *data = pt->ar_rsc;
1093                         return 0;
1094
1095                       case PT_AR_RNAT:
1096                         ptr = pt_reg_addr(pt, ar_rnat);
1097                         break;
1098                       case PT_R1:
1099                         ptr = pt_reg_addr(pt, r1);
1100                         break;
1101                       case PT_R2:  case PT_R3:
1102                         ptr = pt_reg_addr(pt, r2) + (addr - PT_R2);
1103                         break;
1104                       case PT_R8:  case PT_R9:  case PT_R10: case PT_R11:
1105                         ptr = pt_reg_addr(pt, r8) + (addr - PT_R8);
1106                         break;
1107                       case PT_R12: case PT_R13:
1108                         ptr = pt_reg_addr(pt, r12) + (addr - PT_R12);
1109                         break;
1110                       case PT_R14:
1111                         ptr = pt_reg_addr(pt, r14);
1112                         break;
1113                       case PT_R15:
1114                         ptr = pt_reg_addr(pt, r15);
1115                         break;
1116                       case PT_R16: case PT_R17: case PT_R18: case PT_R19:
1117                       case PT_R20: case PT_R21: case PT_R22: case PT_R23:
1118                       case PT_R24: case PT_R25: case PT_R26: case PT_R27:
1119                       case PT_R28: case PT_R29: case PT_R30: case PT_R31:
1120                         ptr = pt_reg_addr(pt, r16) + (addr - PT_R16);
1121                         break;
1122                       case PT_B0:
1123                         ptr = pt_reg_addr(pt, b0);
1124                         break;
1125                       case PT_B6:
1126                         ptr = pt_reg_addr(pt, b6);
1127                         break;
1128                       case PT_B7:
1129                         ptr = pt_reg_addr(pt, b7);
1130                         break;
1131                       case PT_F6:  case PT_F6+8: case PT_F7: case PT_F7+8:
1132                       case PT_F8:  case PT_F8+8: case PT_F9: case PT_F9+8:
1133                         ptr = pt_reg_addr(pt, f6) + (addr - PT_F6);
1134                         break;
1135                       case PT_AR_BSPSTORE:
1136                         ptr = pt_reg_addr(pt, ar_bspstore);
1137                         break;
1138                       case PT_AR_UNAT:
1139                         ptr = pt_reg_addr(pt, ar_unat);
1140                         break;
1141                       case PT_AR_PFS:
1142                         ptr = pt_reg_addr(pt, ar_pfs);
1143                         break;
1144                       case PT_AR_CCV:
1145                         ptr = pt_reg_addr(pt, ar_ccv);
1146                         break;
1147                       case PT_AR_FPSR:
1148                         ptr = pt_reg_addr(pt, ar_fpsr);
1149                         break;
1150                       case PT_CR_IIP:
1151                         ptr = pt_reg_addr(pt, cr_iip);
1152                         break;
1153                       case PT_PR:
1154                         ptr = pt_reg_addr(pt, pr);
1155                         break;
1156                         /* scratch register */
1157
1158                       default:
1159                         /* disallow accessing anything else... */
1160                         dprintk("ptrace: rejecting access to register "
1161                                 "address 0x%lx\n", addr);
1162                         return -1;
1163                 }
1164         } else if (addr <= PT_AR_SSD) {
1165                 ptr = pt_reg_addr(pt, ar_csd) + (addr - PT_AR_CSD);
1166         } else {
1167                 /* access debug registers */
1168
1169                 if (addr >= PT_IBR) {
1170                         regnum = (addr - PT_IBR) >> 3;
1171                         ptr = &child->thread.ibr[0];
1172                 } else {
1173                         regnum = (addr - PT_DBR) >> 3;
1174                         ptr = &child->thread.dbr[0];
1175                 }
1176
1177                 if (regnum >= 8) {
1178                         dprintk("ptrace: rejecting access to register "
1179                                 "address 0x%lx\n", addr);
1180                         return -1;
1181                 }
1182 #ifdef CONFIG_PERFMON
1183                 /*
1184                  * Check if debug registers are used by perfmon. This
1185                  * test must be done once we know that we can do the
1186                  * operation, i.e. the arguments are all valid, but
1187                  * before we start modifying the state.
1188                  *
1189                  * Perfmon needs to keep a count of how many processes
1190                  * are trying to modify the debug registers for system
1191                  * wide monitoring sessions.
1192                  *
1193                  * We also include read access here, because they may
1194                  * cause the PMU-installed debug register state
1195                  * (dbr[], ibr[]) to be reset. The two arrays are also
1196                  * used by perfmon, but we do not use
1197                  * IA64_THREAD_DBG_VALID. The registers are restored
1198                  * by the PMU context switch code.
1199                  */
1200                 if (pfm_use_debug_registers(child)) return -1;
1201 #endif
1202
1203                 if (!(child->thread.flags & IA64_THREAD_DBG_VALID)) {
1204                         child->thread.flags |= IA64_THREAD_DBG_VALID;
1205                         memset(child->thread.dbr, 0,
1206                                sizeof(child->thread.dbr));
1207                         memset(child->thread.ibr, 0,
1208                                sizeof(child->thread.ibr));
1209                 }
1210
1211                 ptr += regnum;
1212
1213                 if ((regnum & 1) && write_access) {
1214                         /* don't let the user set kernel-level breakpoints: */
1215                         *ptr = *data & ~(7UL << 56);
1216                         return 0;
1217                 }
1218         }
1219         if (write_access)
1220                 *ptr = *data;
1221         else
1222                 *data = *ptr;
1223         return 0;
1224 }
1225
1226 static long
1227 ptrace_getregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
1228 {
1229         unsigned long psr, ec, lc, rnat, bsp, cfm, nat_bits, val;
1230         struct unw_frame_info info;
1231         struct ia64_fpreg fpval;
1232         struct switch_stack *sw;
1233         struct pt_regs *pt;
1234         long ret, retval = 0;
1235         char nat = 0;
1236         int i;
1237
1238         if (!access_ok(VERIFY_WRITE, ppr, sizeof(struct pt_all_user_regs)))
1239                 return -EIO;
1240
1241         pt = task_pt_regs(child);
1242         sw = (struct switch_stack *) (child->thread.ksp + 16);
1243         unw_init_from_blocked_task(&info, child);
1244         if (unw_unwind_to_user(&info) < 0) {
1245                 return -EIO;
1246         }
1247
1248         if (((unsigned long) ppr & 0x7) != 0) {
1249                 dprintk("ptrace:unaligned register address %p\n", ppr);
1250                 return -EIO;
1251         }
1252
1253         if (access_uarea(child, PT_CR_IPSR, &psr, 0) < 0
1254             || access_uarea(child, PT_AR_EC, &ec, 0) < 0
1255             || access_uarea(child, PT_AR_LC, &lc, 0) < 0
1256             || access_uarea(child, PT_AR_RNAT, &rnat, 0) < 0
1257             || access_uarea(child, PT_AR_BSP, &bsp, 0) < 0
1258             || access_uarea(child, PT_CFM, &cfm, 0)
1259             || access_uarea(child, PT_NAT_BITS, &nat_bits, 0))
1260                 return -EIO;
1261
1262         /* control regs */
1263
1264         retval |= __put_user(pt->cr_iip, &ppr->cr_iip);
1265         retval |= __put_user(psr, &ppr->cr_ipsr);
1266
1267         /* app regs */
1268
1269         retval |= __put_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
1270         retval |= __put_user(pt->ar_rsc, &ppr->ar[PT_AUR_RSC]);
1271         retval |= __put_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
1272         retval |= __put_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
1273         retval |= __put_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
1274         retval |= __put_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);
1275
1276         retval |= __put_user(ec, &ppr->ar[PT_AUR_EC]);
1277         retval |= __put_user(lc, &ppr->ar[PT_AUR_LC]);
1278         retval |= __put_user(rnat, &ppr->ar[PT_AUR_RNAT]);
1279         retval |= __put_user(bsp, &ppr->ar[PT_AUR_BSP]);
1280         retval |= __put_user(cfm, &ppr->cfm);
1281
1282         /* gr1-gr3 */
1283
1284         retval |= __copy_to_user(&ppr->gr[1], &pt->r1, sizeof(long));
1285         retval |= __copy_to_user(&ppr->gr[2], &pt->r2, sizeof(long) *2);
1286
1287         /* gr4-gr7 */
1288
1289         for (i = 4; i < 8; i++) {
1290                 if (unw_access_gr(&info, i, &val, &nat, 0) < 0)
1291                         return -EIO;
1292                 retval |= __put_user(val, &ppr->gr[i]);
1293         }
1294
1295         /* gr8-gr11 */
1296
1297         retval |= __copy_to_user(&ppr->gr[8], &pt->r8, sizeof(long) * 4);
1298
1299         /* gr12-gr15 */
1300
1301         retval |= __copy_to_user(&ppr->gr[12], &pt->r12, sizeof(long) * 2);
1302         retval |= __copy_to_user(&ppr->gr[14], &pt->r14, sizeof(long));
1303         retval |= __copy_to_user(&ppr->gr[15], &pt->r15, sizeof(long));
1304
1305         /* gr16-gr31 */
1306
1307         retval |= __copy_to_user(&ppr->gr[16], &pt->r16, sizeof(long) * 16);
1308
1309         /* b0 */
1310
1311         retval |= __put_user(pt->b0, &ppr->br[0]);
1312
1313         /* b1-b5 */
1314
1315         for (i = 1; i < 6; i++) {
1316                 if (unw_access_br(&info, i, &val, 0) < 0)
1317                         return -EIO;
1318                 __put_user(val, &ppr->br[i]);
1319         }
1320
1321         /* b6-b7 */
1322
1323         retval |= __put_user(pt->b6, &ppr->br[6]);
1324         retval |= __put_user(pt->b7, &ppr->br[7]);
1325
1326         /* fr2-fr5 */
1327
1328         for (i = 2; i < 6; i++) {
1329                 if (unw_get_fr(&info, i, &fpval) < 0)
1330                         return -EIO;
1331                 retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
1332         }
1333
1334         /* fr6-fr11 */
1335
1336         retval |= __copy_to_user(&ppr->fr[6], &pt->f6,
1337                                  sizeof(struct ia64_fpreg) * 6);
1338
1339         /* fp scratch regs(12-15) */
1340
1341         retval |= __copy_to_user(&ppr->fr[12], &sw->f12,
1342                                  sizeof(struct ia64_fpreg) * 4);
1343
1344         /* fr16-fr31 */
1345
1346         for (i = 16; i < 32; i++) {
1347                 if (unw_get_fr(&info, i, &fpval) < 0)
1348                         return -EIO;
1349                 retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
1350         }
1351
1352         /* fph */
1353
1354         ia64_flush_fph(child);
1355         retval |= __copy_to_user(&ppr->fr[32], &child->thread.fph,
1356                                  sizeof(ppr->fr[32]) * 96);
1357
1358         /*  preds */
1359
1360         retval |= __put_user(pt->pr, &ppr->pr);
1361
1362         /* nat bits */
1363
1364         retval |= __put_user(nat_bits, &ppr->nat);
1365
1366         ret = retval ? -EIO : 0;
1367         return ret;
1368 }
1369
1370 static long
1371 ptrace_setregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
1372 {
1373         unsigned long psr, rsc, ec, lc, rnat, bsp, cfm, nat_bits, val = 0;
1374         struct unw_frame_info info;
1375         struct switch_stack *sw;
1376         struct ia64_fpreg fpval;
1377         struct pt_regs *pt;
1378         long ret, retval = 0;
1379         int i;
1380
1381         memset(&fpval, 0, sizeof(fpval));
1382
1383         if (!access_ok(VERIFY_READ, ppr, sizeof(struct pt_all_user_regs)))
1384                 return -EIO;
1385
1386         pt = task_pt_regs(child);
1387         sw = (struct switch_stack *) (child->thread.ksp + 16);
1388         unw_init_from_blocked_task(&info, child);
1389         if (unw_unwind_to_user(&info) < 0) {
1390                 return -EIO;
1391         }
1392
1393         if (((unsigned long) ppr & 0x7) != 0) {
1394                 dprintk("ptrace:unaligned register address %p\n", ppr);
1395                 return -EIO;
1396         }
1397
1398         /* control regs */
1399
1400         retval |= __get_user(pt->cr_iip, &ppr->cr_iip);
1401         retval |= __get_user(psr, &ppr->cr_ipsr);
1402
1403         /* app regs */
1404
1405         retval |= __get_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
1406         retval |= __get_user(rsc, &ppr->ar[PT_AUR_RSC]);
1407         retval |= __get_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
1408         retval |= __get_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
1409         retval |= __get_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
1410         retval |= __get_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);
1411
1412         retval |= __get_user(ec, &ppr->ar[PT_AUR_EC]);
1413         retval |= __get_user(lc, &ppr->ar[PT_AUR_LC]);
1414         retval |= __get_user(rnat, &ppr->ar[PT_AUR_RNAT]);
1415         retval |= __get_user(bsp, &ppr->ar[PT_AUR_BSP]);
1416         retval |= __get_user(cfm, &ppr->cfm);
1417
1418         /* gr1-gr3 */
1419
1420         retval |= __copy_from_user(&pt->r1, &ppr->gr[1], sizeof(long));
1421         retval |= __copy_from_user(&pt->r2, &ppr->gr[2], sizeof(long) * 2);
1422
1423         /* gr4-gr7 */
1424
1425         for (i = 4; i < 8; i++) {
1426                 retval |= __get_user(val, &ppr->gr[i]);
1427                 /* NaT bit will be set via PT_NAT_BITS: */
1428                 if (unw_set_gr(&info, i, val, 0) < 0)
1429                         return -EIO;
1430         }
1431
1432         /* gr8-gr11 */
1433
1434         retval |= __copy_from_user(&pt->r8, &ppr->gr[8], sizeof(long) * 4);
1435
1436         /* gr12-gr15 */
1437
1438         retval |= __copy_from_user(&pt->r12, &ppr->gr[12], sizeof(long) * 2);
1439         retval |= __copy_from_user(&pt->r14, &ppr->gr[14], sizeof(long));
1440         retval |= __copy_from_user(&pt->r15, &ppr->gr[15], sizeof(long));
1441
1442         /* gr16-gr31 */
1443
1444         retval |= __copy_from_user(&pt->r16, &ppr->gr[16], sizeof(long) * 16);
1445
1446         /* b0 */
1447
1448         retval |= __get_user(pt->b0, &ppr->br[0]);
1449
1450         /* b1-b5 */
1451
1452         for (i = 1; i < 6; i++) {
1453                 retval |= __get_user(val, &ppr->br[i]);
1454                 unw_set_br(&info, i, val);
1455         }
1456
1457         /* b6-b7 */
1458
1459         retval |= __get_user(pt->b6, &ppr->br[6]);
1460         retval |= __get_user(pt->b7, &ppr->br[7]);
1461
1462         /* fr2-fr5 */
1463
1464         for (i = 2; i < 6; i++) {
1465                 retval |= __copy_from_user(&fpval, &ppr->fr[i], sizeof(fpval));
1466                 if (unw_set_fr(&info, i, fpval) < 0)
1467                         return -EIO;
1468         }
1469
1470         /* fr6-fr11 */
1471
1472         retval |= __copy_from_user(&pt->f6, &ppr->fr[6],
1473                                    sizeof(ppr->fr[6]) * 6);
1474
1475         /* fp scratch regs(12-15) */
1476
1477         retval |= __copy_from_user(&sw->f12, &ppr->fr[12],
1478                                    sizeof(ppr->fr[12]) * 4);
1479
1480         /* fr16-fr31 */
1481
1482         for (i = 16; i < 32; i++) {
1483                 retval |= __copy_from_user(&fpval, &ppr->fr[i],
1484                                            sizeof(fpval));
1485                 if (unw_set_fr(&info, i, fpval) < 0)
1486                         return -EIO;
1487         }
1488
1489         /* fph */
1490
1491         ia64_sync_fph(child);
1492         retval |= __copy_from_user(&child->thread.fph, &ppr->fr[32],
1493                                    sizeof(ppr->fr[32]) * 96);
1494
1495         /* preds */
1496
1497         retval |= __get_user(pt->pr, &ppr->pr);
1498
1499         /* nat bits */
1500
1501         retval |= __get_user(nat_bits, &ppr->nat);
1502
1503         retval |= access_uarea(child, PT_CR_IPSR, &psr, 1);
1504         retval |= access_uarea(child, PT_AR_RSC, &rsc, 1);
1505         retval |= access_uarea(child, PT_AR_EC, &ec, 1);
1506         retval |= access_uarea(child, PT_AR_LC, &lc, 1);
1507         retval |= access_uarea(child, PT_AR_RNAT, &rnat, 1);
1508         retval |= access_uarea(child, PT_AR_BSP, &bsp, 1);
1509         retval |= access_uarea(child, PT_CFM, &cfm, 1);
1510         retval |= access_uarea(child, PT_NAT_BITS, &nat_bits, 1);
1511
1512         ret = retval ? -EIO : 0;
1513         return ret;
1514 }
1515
1516 /*
1517  * Called by kernel/ptrace.c when detaching..
1518  *
1519  * Make sure the single step bit is not set.
1520  */
1521 void
1522 ptrace_disable (struct task_struct *child)
1523 {
1524         struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
1525
1526         /* make sure the single step/taken-branch trap bits are not set: */
1527         clear_tsk_thread_flag(child, TIF_SINGLESTEP);
1528         child_psr->ss = 0;
1529         child_psr->tb = 0;
1530 }
1531
1532 asmlinkage long
1533 sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data)
1534 {
1535         struct pt_regs *pt;
1536         unsigned long peek_or_poke;
1537         struct task_struct *child;
1538         struct switch_stack *sw;
1539         long ret;
1540
1541         lock_kernel();
1542         ret = -EPERM;
1543         if (request == PTRACE_TRACEME) {
1544                 ret = ptrace_traceme();
1545                 goto out;
1546         }
1547
1548         peek_or_poke = (request == PTRACE_PEEKTEXT
1549                         || request == PTRACE_PEEKDATA
1550                         || request == PTRACE_POKETEXT
1551                         || request == PTRACE_POKEDATA);
1552         ret = -ESRCH;
1553         read_lock(&tasklist_lock);
1554         {
1555                 child = find_task_by_pid(pid);
1556                 if (child) {
1557                         if (peek_or_poke)
1558                                 child = find_thread_for_addr(child, addr);
1559                         get_task_struct(child);
1560                 }
1561         }
1562         read_unlock(&tasklist_lock);
1563         if (!child)
1564                 goto out;
1565         ret = -EPERM;
1566         if (pid == 1)           /* no messing around with init! */
1567                 goto out_tsk;
1568
1569         if (request == PTRACE_ATTACH) {
1570                 ret = ptrace_attach(child);
1571                 if (!ret)
1572                         arch_ptrace_attach(child);
1573                 goto out_tsk;
1574         }
1575
1576         ret = ptrace_check_attach(child, request == PTRACE_KILL);
1577         if (ret < 0)
1578                 goto out_tsk;
1579
1580         pt = task_pt_regs(child);
1581         sw = (struct switch_stack *) (child->thread.ksp + 16);
1582
1583         switch (request) {
1584               case PTRACE_PEEKTEXT:
1585               case PTRACE_PEEKDATA:
1586                 /* read word at location addr */
1587                 if (access_process_vm(child, addr, &data, sizeof(data), 0)
1588                     != sizeof(data)) {
1589                         ret = -EIO;
1590                         goto out_tsk;
1591                 }
1592                 ret = data;
1593                 /* ensure "ret" is not mistaken as an error code */
1594                 force_successful_syscall_return();
1595                 goto out_tsk;
1596
1597         /* PTRACE_POKETEXT and PTRACE_POKEDATA is handled
1598          * by the generic ptrace_request().
1599          */
1600
1601               case PTRACE_PEEKUSR:
1602                 /* read the word at addr in the USER area */
1603                 if (access_uarea(child, addr, &data, 0) < 0) {
1604                         ret = -EIO;
1605                         goto out_tsk;
1606                 }
1607                 ret = data;
1608                 /* ensure "ret" is not mistaken as an error code */
1609                 force_successful_syscall_return();
1610                 goto out_tsk;
1611
1612               case PTRACE_POKEUSR:
1613                 /* write the word at addr in the USER area */
1614                 if (access_uarea(child, addr, &data, 1) < 0) {
1615                         ret = -EIO;
1616                         goto out_tsk;
1617                 }
1618                 ret = 0;
1619                 goto out_tsk;
1620
1621               case PTRACE_OLD_GETSIGINFO:
1622                 /* for backwards-compatibility */
1623                 ret = ptrace_request(child, PTRACE_GETSIGINFO, addr, data);
1624                 goto out_tsk;
1625
1626               case PTRACE_OLD_SETSIGINFO:
1627                 /* for backwards-compatibility */
1628                 ret = ptrace_request(child, PTRACE_SETSIGINFO, addr, data);
1629                 goto out_tsk;
1630
1631               case PTRACE_SYSCALL:
1632                 /* continue and stop at next (return from) syscall */
1633               case PTRACE_CONT:
1634                 /* restart after signal. */
1635                 ret = -EIO;
1636                 if (!valid_signal(data))
1637                         goto out_tsk;
1638                 if (request == PTRACE_SYSCALL)
1639                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
1640                 else
1641                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
1642                 child->exit_code = data;
1643
1644                 /*
1645                  * Make sure the single step/taken-branch trap bits
1646                  * are not set:
1647                  */
1648                 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
1649                 ia64_psr(pt)->ss = 0;
1650                 ia64_psr(pt)->tb = 0;
1651
1652                 wake_up_process(child);
1653                 ret = 0;
1654                 goto out_tsk;
1655
1656               case PTRACE_KILL:
1657                 /*
1658                  * Make the child exit.  Best I can do is send it a
1659                  * sigkill.  Perhaps it should be put in the status
1660                  * that it wants to exit.
1661                  */
1662                 if (child->exit_state == EXIT_ZOMBIE)
1663                         /* already dead */
1664                         goto out_tsk;
1665                 child->exit_code = SIGKILL;
1666
1667                 ptrace_disable(child);
1668                 wake_up_process(child);
1669                 ret = 0;
1670                 goto out_tsk;
1671
1672               case PTRACE_SINGLESTEP:
1673                 /* let child execute for one instruction */
1674               case PTRACE_SINGLEBLOCK:
1675                 ret = -EIO;
1676                 if (!valid_signal(data))
1677                         goto out_tsk;
1678
1679                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
1680                 set_tsk_thread_flag(child, TIF_SINGLESTEP);
1681                 if (request == PTRACE_SINGLESTEP) {
1682                         ia64_psr(pt)->ss = 1;
1683                 } else {
1684                         ia64_psr(pt)->tb = 1;
1685                 }
1686                 child->exit_code = data;
1687
1688                 /* give it a chance to run. */
1689                 wake_up_process(child);
1690                 ret = 0;
1691                 goto out_tsk;
1692
1693               case PTRACE_DETACH:
1694                 /* detach a process that was attached. */
1695                 ret = ptrace_detach(child, data);
1696                 goto out_tsk;
1697
1698               case PTRACE_GETREGS:
1699                 ret = ptrace_getregs(child,
1700                                      (struct pt_all_user_regs __user *) data);
1701                 goto out_tsk;
1702
1703               case PTRACE_SETREGS:
1704                 ret = ptrace_setregs(child,
1705                                      (struct pt_all_user_regs __user *) data);
1706                 goto out_tsk;
1707
1708               default:
1709                 ret = ptrace_request(child, request, addr, data);
1710                 goto out_tsk;
1711         }
1712   out_tsk:
1713         put_task_struct(child);
1714   out:
1715         unlock_kernel();
1716         return ret;
1717 }
1718
1719
1720 static void
1721 syscall_trace (void)
1722 {
1723         /*
1724          * The 0x80 provides a way for the tracing parent to
1725          * distinguish between a syscall stop and SIGTRAP delivery.
1726          */
1727         ptrace_notify(SIGTRAP
1728                       | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
1729
1730         /*
1731          * This isn't the same as continuing with a signal, but it
1732          * will do for normal use.  strace only continues with a
1733          * signal if the stopping signal is not SIGTRAP.  -brl
1734          */
1735         if (current->exit_code) {
1736                 send_sig(current->exit_code, current, 1);
1737                 current->exit_code = 0;
1738         }
1739 }
1740
1741 /* "asmlinkage" so the input arguments are preserved... */
1742
1743 asmlinkage void
1744 syscall_trace_enter (long arg0, long arg1, long arg2, long arg3,
1745                      long arg4, long arg5, long arg6, long arg7,
1746                      struct pt_regs regs)
1747 {
1748         if (test_thread_flag(TIF_SYSCALL_TRACE) 
1749             && (current->ptrace & PT_PTRACED))
1750                 syscall_trace();
1751
1752         /* copy user rbs to kernel rbs */
1753         if (test_thread_flag(TIF_RESTORE_RSE))
1754                 ia64_sync_krbs();
1755
1756         if (unlikely(current->audit_context)) {
1757                 long syscall;
1758                 int arch;
1759
1760                 if (IS_IA32_PROCESS(&regs)) {
1761                         syscall = regs.r1;
1762                         arch = AUDIT_ARCH_I386;
1763                 } else {
1764                         syscall = regs.r15;
1765                         arch = AUDIT_ARCH_IA64;
1766                 }
1767
1768                 audit_syscall_entry(arch, syscall, arg0, arg1, arg2, arg3);
1769         }
1770
1771 }
1772
1773 /* "asmlinkage" so the input arguments are preserved... */
1774
1775 asmlinkage void
1776 syscall_trace_leave (long arg0, long arg1, long arg2, long arg3,
1777                      long arg4, long arg5, long arg6, long arg7,
1778                      struct pt_regs regs)
1779 {
1780         if (unlikely(current->audit_context)) {
1781                 int success = AUDITSC_RESULT(regs.r10);
1782                 long result = regs.r8;
1783
1784                 if (success != AUDITSC_SUCCESS)
1785                         result = -result;
1786                 audit_syscall_exit(success, result);
1787         }
1788
1789         if ((test_thread_flag(TIF_SYSCALL_TRACE)
1790             || test_thread_flag(TIF_SINGLESTEP))
1791             && (current->ptrace & PT_PTRACED))
1792                 syscall_trace();
1793
1794         /* copy user rbs to kernel rbs */
1795         if (test_thread_flag(TIF_RESTORE_RSE))
1796                 ia64_sync_krbs();
1797 }