PTRACE_PEEKDATA consolidation
[deliverable/linux.git] / arch / i386 / kernel / ptrace.c
CommitLineData
1da177e4
LT
1/* ptrace.c */
2/* By Ross Biro 1/23/92 */
3/*
4 * Pentium III FXSR, SSE support
5 * Gareth Hughes <gareth@valinux.com>, May 2000
6 */
7
8#include <linux/kernel.h>
9#include <linux/sched.h>
10#include <linux/mm.h>
11#include <linux/smp.h>
1da177e4
LT
12#include <linux/errno.h>
13#include <linux/ptrace.h>
14#include <linux/user.h>
15#include <linux/security.h>
16#include <linux/audit.h>
17#include <linux/seccomp.h>
7ed20e1a 18#include <linux/signal.h>
1da177e4
LT
19
20#include <asm/uaccess.h>
21#include <asm/pgtable.h>
22#include <asm/system.h>
23#include <asm/processor.h>
24#include <asm/i387.h>
25#include <asm/debugreg.h>
26#include <asm/ldt.h>
27#include <asm/desc.h>
28
29/*
30 * does not yet catch signals sent when the child dies.
31 * in exit.c or in signal.c.
32 */
33
9f155b98
CE
34/*
35 * Determines which flags the user has access to [1 = access, 0 = no access].
3c36c6aa 36 * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), NT(14), IOPL(12-13), IF(9).
9f155b98
CE
37 * Also masks reserved bits (31-22, 15, 5, 3, 1).
38 */
3c36c6aa 39#define FLAG_MASK 0x00050dd5
1da177e4
LT
40
41/* set's the trap flag. */
42#define TRAP_FLAG 0x100
43
44/*
45 * Offset of eflags on child stack..
46 */
8701ea95 47#define EFL_OFFSET offsetof(struct pt_regs, eflags)
1da177e4
LT
48
49static inline struct pt_regs *get_child_regs(struct task_struct *task)
50{
51 void *stack_top = (void *)task->thread.esp0;
52 return stack_top - sizeof(struct pt_regs);
53}
54
55/*
8701ea95
JF
56 * This routine will get a word off of the processes privileged stack.
57 * the offset is bytes into the pt_regs structure on the stack.
58 * This routine assumes that all the privileged stacks are in our
1da177e4
LT
59 * data space.
60 */
61static inline int get_stack_long(struct task_struct *task, int offset)
62{
63 unsigned char *stack;
64
8701ea95 65 stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs);
1da177e4
LT
66 stack += offset;
67 return (*((int *)stack));
68}
69
70/*
8701ea95
JF
71 * This routine will put a word on the processes privileged stack.
72 * the offset is bytes into the pt_regs structure on the stack.
73 * This routine assumes that all the privileged stacks are in our
1da177e4
LT
74 * data space.
75 */
76static inline int put_stack_long(struct task_struct *task, int offset,
77 unsigned long data)
78{
79 unsigned char * stack;
80
8701ea95 81 stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs);
1da177e4
LT
82 stack += offset;
83 *(unsigned long *) stack = data;
84 return 0;
85}
86
87static int putreg(struct task_struct *child,
88 unsigned long regno, unsigned long value)
89{
90 switch (regno >> 2) {
464d1a78 91 case GS:
1da177e4
LT
92 if (value && (value & 3) != 3)
93 return -EIO;
464d1a78 94 child->thread.gs = value;
1da177e4 95 return 0;
1da177e4
LT
96 case DS:
97 case ES:
464d1a78 98 case FS:
1da177e4
LT
99 if (value && (value & 3) != 3)
100 return -EIO;
101 value &= 0xffff;
102 break;
103 case SS:
104 case CS:
105 if ((value & 3) != 3)
106 return -EIO;
107 value &= 0xffff;
108 break;
109 case EFL:
110 value &= FLAG_MASK;
111 value |= get_stack_long(child, EFL_OFFSET) & ~FLAG_MASK;
112 break;
113 }
464d1a78 114 if (regno > FS*4)
66e10a44 115 regno -= 1*4;
8701ea95 116 put_stack_long(child, regno, value);
1da177e4
LT
117 return 0;
118}
119
120static unsigned long getreg(struct task_struct *child,
121 unsigned long regno)
122{
123 unsigned long retval = ~0UL;
124
125 switch (regno >> 2) {
464d1a78
JF
126 case GS:
127 retval = child->thread.gs;
1da177e4 128 break;
1da177e4
LT
129 case DS:
130 case ES:
464d1a78 131 case FS:
1da177e4
LT
132 case SS:
133 case CS:
134 retval = 0xffff;
135 /* fall through */
136 default:
464d1a78 137 if (regno > FS*4)
66e10a44 138 regno -= 1*4;
1da177e4
LT
139 retval &= get_stack_long(child, regno);
140 }
141 return retval;
142}
143
144#define LDT_SEGMENT 4
145
146static unsigned long convert_eip_to_linear(struct task_struct *child, struct pt_regs *regs)
147{
148 unsigned long addr, seg;
149
150 addr = regs->eip;
151 seg = regs->xcs & 0xffff;
152 if (regs->eflags & VM_MASK) {
153 addr = (addr & 0xffff) + (seg << 4);
154 return addr;
155 }
156
157 /*
158 * We'll assume that the code segments in the GDT
159 * are all zero-based. That is largely true: the
160 * TLS segments are used for data, and the PNPBIOS
161 * and APM bios ones we just ignore here.
162 */
163 if (seg & LDT_SEGMENT) {
164 u32 *desc;
165 unsigned long base;
166
167 down(&child->mm->context.sem);
168 desc = child->mm->context.ldt + (seg & ~7);
169 base = (desc[0] >> 16) | ((desc[1] & 0xff) << 16) | (desc[1] & 0xff000000);
170
171 /* 16-bit code segment? */
172 if (!((desc[1] >> 22) & 1))
173 addr &= 0xffff;
174 addr += base;
175 up(&child->mm->context.sem);
176 }
177 return addr;
178}
179
2ade2920 180static inline int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs)
1da177e4
LT
181{
182 int i, copied;
2ade2920 183 unsigned char opcode[15];
1da177e4
LT
184 unsigned long addr = convert_eip_to_linear(child, regs);
185
186 copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0);
187 for (i = 0; i < copied; i++) {
188 switch (opcode[i]) {
2ade2920
CE
189 /* popf and iret */
190 case 0x9d: case 0xcf:
1da177e4
LT
191 return 1;
192 /* opcode and address size prefixes */
193 case 0x66: case 0x67:
194 continue;
195 /* irrelevant prefixes (segment overrides and repeats) */
196 case 0x26: case 0x2e:
197 case 0x36: case 0x3e:
198 case 0x64: case 0x65:
199 case 0xf0: case 0xf2: case 0xf3:
200 continue;
201
202 /*
203 * pushf: NOTE! We should probably not let
204 * the user see the TF bit being set. But
205 * it's more pain than it's worth to avoid
206 * it, and a debugger could emulate this
207 * all in user space if it _really_ cares.
208 */
209 case 0x9c:
210 default:
211 return 0;
212 }
213 }
214 return 0;
215}
216
217static void set_singlestep(struct task_struct *child)
218{
219 struct pt_regs *regs = get_child_regs(child);
220
221 /*
222 * Always set TIF_SINGLESTEP - this guarantees that
223 * we single-step system calls etc.. This will also
224 * cause us to set TF when returning to user mode.
225 */
226 set_tsk_thread_flag(child, TIF_SINGLESTEP);
227
228 /*
229 * If TF was already set, don't do anything else
230 */
231 if (regs->eflags & TRAP_FLAG)
232 return;
233
234 /* Set TF on the kernel stack.. */
235 regs->eflags |= TRAP_FLAG;
236
237 /*
238 * ..but if TF is changed by the instruction we will trace,
239 * don't mark it as being "us" that set it, so that we
240 * won't clear it by hand later.
241 */
2ade2920 242 if (is_setting_trap_flag(child, regs))
1da177e4
LT
243 return;
244
245 child->ptrace |= PT_DTRACE;
246}
247
248static void clear_singlestep(struct task_struct *child)
249{
250 /* Always clear TIF_SINGLESTEP... */
251 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
252
253 /* But touch TF only if it was set by us.. */
254 if (child->ptrace & PT_DTRACE) {
255 struct pt_regs *regs = get_child_regs(child);
256 regs->eflags &= ~TRAP_FLAG;
257 child->ptrace &= ~PT_DTRACE;
258 }
259}
260
261/*
262 * Called by kernel/ptrace.c when detaching..
263 *
264 * Make sure the single step bit is not set.
265 */
266void ptrace_disable(struct task_struct *child)
267{
268 clear_singlestep(child);
ab1c23c2
BS
269 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
270 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
1da177e4
LT
271}
272
273/*
274 * Perform get_thread_area on behalf of the traced child.
275 */
276static int
277ptrace_get_thread_area(struct task_struct *child,
278 int idx, struct user_desc __user *user_desc)
279{
280 struct user_desc info;
281 struct desc_struct *desc;
282
283/*
284 * Get the current Thread-Local Storage area:
285 */
286
287#define GET_BASE(desc) ( \
288 (((desc)->a >> 16) & 0x0000ffff) | \
289 (((desc)->b << 16) & 0x00ff0000) | \
290 ( (desc)->b & 0xff000000) )
291
292#define GET_LIMIT(desc) ( \
293 ((desc)->a & 0x0ffff) | \
294 ((desc)->b & 0xf0000) )
295
296#define GET_32BIT(desc) (((desc)->b >> 22) & 1)
297#define GET_CONTENTS(desc) (((desc)->b >> 10) & 3)
298#define GET_WRITABLE(desc) (((desc)->b >> 9) & 1)
299#define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1)
300#define GET_PRESENT(desc) (((desc)->b >> 15) & 1)
301#define GET_USEABLE(desc) (((desc)->b >> 20) & 1)
302
303 if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
304 return -EINVAL;
305
306 desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
307
308 info.entry_number = idx;
309 info.base_addr = GET_BASE(desc);
310 info.limit = GET_LIMIT(desc);
311 info.seg_32bit = GET_32BIT(desc);
312 info.contents = GET_CONTENTS(desc);
313 info.read_exec_only = !GET_WRITABLE(desc);
314 info.limit_in_pages = GET_LIMIT_PAGES(desc);
315 info.seg_not_present = !GET_PRESENT(desc);
316 info.useable = GET_USEABLE(desc);
317
318 if (copy_to_user(user_desc, &info, sizeof(info)))
319 return -EFAULT;
320
321 return 0;
322}
323
324/*
325 * Perform set_thread_area on behalf of the traced child.
326 */
327static int
328ptrace_set_thread_area(struct task_struct *child,
329 int idx, struct user_desc __user *user_desc)
330{
331 struct user_desc info;
332 struct desc_struct *desc;
333
334 if (copy_from_user(&info, user_desc, sizeof(info)))
335 return -EFAULT;
336
337 if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
338 return -EINVAL;
339
340 desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
341 if (LDT_empty(&info)) {
342 desc->a = 0;
343 desc->b = 0;
344 } else {
345 desc->a = LDT_entry_a(&info);
346 desc->b = LDT_entry_b(&info);
347 }
348
349 return 0;
350}
351
481bed45 352long arch_ptrace(struct task_struct *child, long request, long addr, long data)
1da177e4 353{
1da177e4
LT
354 struct user * dummy = NULL;
355 int i, ret;
356 unsigned long __user *datap = (unsigned long __user *)data;
357
1da177e4
LT
358 switch (request) {
359 /* when I and D space are separate, these will need to be fixed. */
360 case PTRACE_PEEKTEXT: /* read word at location addr. */
76647323
AD
361 case PTRACE_PEEKDATA:
362 ret = generic_ptrace_peekdata(child, addr, data);
1da177e4 363 break;
1da177e4
LT
364
365 /* read the word at location addr in the USER area. */
366 case PTRACE_PEEKUSR: {
367 unsigned long tmp;
368
369 ret = -EIO;
370 if ((addr & 3) || addr < 0 ||
371 addr > sizeof(struct user) - 3)
372 break;
373
374 tmp = 0; /* Default return condition */
375 if(addr < FRAME_SIZE*sizeof(long))
376 tmp = getreg(child, addr);
377 if(addr >= (long) &dummy->u_debugreg[0] &&
378 addr <= (long) &dummy->u_debugreg[7]){
379 addr -= (long) &dummy->u_debugreg[0];
380 addr = addr >> 2;
381 tmp = child->thread.debugreg[addr];
382 }
383 ret = put_user(tmp, datap);
384 break;
385 }
386
387 /* when I and D space are separate, this will have to be fixed. */
388 case PTRACE_POKETEXT: /* write the word at location addr. */
389 case PTRACE_POKEDATA:
390 ret = 0;
391 if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
392 break;
393 ret = -EIO;
394 break;
395
396 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
397 ret = -EIO;
398 if ((addr & 3) || addr < 0 ||
399 addr > sizeof(struct user) - 3)
400 break;
401
402 if (addr < FRAME_SIZE*sizeof(long)) {
403 ret = putreg(child, addr, data);
404 break;
405 }
406 /* We need to be very careful here. We implicitly
407 want to modify a portion of the task_struct, and we
408 have to be selective about what portions we allow someone
409 to modify. */
410
411 ret = -EIO;
412 if(addr >= (long) &dummy->u_debugreg[0] &&
413 addr <= (long) &dummy->u_debugreg[7]){
414
415 if(addr == (long) &dummy->u_debugreg[4]) break;
416 if(addr == (long) &dummy->u_debugreg[5]) break;
417 if(addr < (long) &dummy->u_debugreg[4] &&
418 ((unsigned long) data) >= TASK_SIZE-3) break;
419
420 /* Sanity-check data. Take one half-byte at once with
421 * check = (val >> (16 + 4*i)) & 0xf. It contains the
422 * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits
423 * 2 and 3 are LENi. Given a list of invalid values,
424 * we do mask |= 1 << invalid_value, so that
425 * (mask >> check) & 1 is a correct test for invalid
426 * values.
427 *
428 * R/Wi contains the type of the breakpoint /
429 * watchpoint, LENi contains the length of the watched
430 * data in the watchpoint case.
431 *
432 * The invalid values are:
433 * - LENi == 0x10 (undefined), so mask |= 0x0f00.
434 * - R/Wi == 0x10 (break on I/O reads or writes), so
435 * mask |= 0x4444.
436 * - R/Wi == 0x00 && LENi != 0x00, so we have mask |=
437 * 0x1110.
438 *
439 * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54.
440 *
441 * See the Intel Manual "System Programming Guide",
442 * 15.2.4
443 *
444 * Note that LENi == 0x10 is defined on x86_64 in long
445 * mode (i.e. even for 32-bit userspace software, but
446 * 64-bit kernel), so the x86_64 mask value is 0x5454.
447 * See the AMD manual no. 24593 (AMD64 System
448 * Programming)*/
449
450 if(addr == (long) &dummy->u_debugreg[7]) {
451 data &= ~DR_CONTROL_RESERVED;
452 for(i=0; i<4; i++)
453 if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
454 goto out_tsk;
b3cf2576
SE
455 if (data)
456 set_tsk_thread_flag(child, TIF_DEBUG);
457 else
458 clear_tsk_thread_flag(child, TIF_DEBUG);
1da177e4 459 }
1da177e4
LT
460 addr -= (long) &dummy->u_debugreg;
461 addr = addr >> 2;
462 child->thread.debugreg[addr] = data;
463 ret = 0;
464 }
465 break;
466
ed75e8d5 467 case PTRACE_SYSEMU: /* continue and stop at next syscall, which will not be executed */
1da177e4
LT
468 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
469 case PTRACE_CONT: /* restart after signal. */
470 ret = -EIO;
7ed20e1a 471 if (!valid_signal(data))
1da177e4 472 break;
ed75e8d5
LV
473 if (request == PTRACE_SYSEMU) {
474 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
c8c86cec
BS
475 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
476 } else if (request == PTRACE_SYSCALL) {
1da177e4 477 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
c8c86cec 478 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
ed75e8d5 479 } else {
c8c86cec 480 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
1da177e4
LT
481 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
482 }
483 child->exit_code = data;
484 /* make sure the single step bit is not set. */
485 clear_singlestep(child);
486 wake_up_process(child);
487 ret = 0;
488 break;
489
490/*
491 * make the child exit. Best I can do is send it a sigkill.
492 * perhaps it should be put in the status that it wants to
493 * exit.
494 */
495 case PTRACE_KILL:
496 ret = 0;
497 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
498 break;
499 child->exit_code = SIGKILL;
500 /* make sure the single step bit is not set. */
501 clear_singlestep(child);
502 wake_up_process(child);
503 break;
504
1b38f006 505 case PTRACE_SYSEMU_SINGLESTEP: /* Same as SYSEMU, but singlestep if not syscall */
1da177e4
LT
506 case PTRACE_SINGLESTEP: /* set the trap flag. */
507 ret = -EIO;
7ed20e1a 508 if (!valid_signal(data))
1da177e4 509 break;
1b38f006
BS
510
511 if (request == PTRACE_SYSEMU_SINGLESTEP)
512 set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
513 else
514 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
515
1da177e4
LT
516 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
517 set_singlestep(child);
518 child->exit_code = data;
519 /* give it a chance to run. */
520 wake_up_process(child);
521 ret = 0;
522 break;
523
524 case PTRACE_DETACH:
525 /* detach a process that was attached. */
526 ret = ptrace_detach(child, data);
527 break;
528
529 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
530 if (!access_ok(VERIFY_WRITE, datap, FRAME_SIZE*sizeof(long))) {
531 ret = -EIO;
532 break;
533 }
534 for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {
535 __put_user(getreg(child, i), datap);
536 datap++;
537 }
538 ret = 0;
539 break;
540 }
541
542 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
543 unsigned long tmp;
544 if (!access_ok(VERIFY_READ, datap, FRAME_SIZE*sizeof(long))) {
545 ret = -EIO;
546 break;
547 }
548 for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {
549 __get_user(tmp, datap);
550 putreg(child, i, tmp);
551 datap++;
552 }
553 ret = 0;
554 break;
555 }
556
557 case PTRACE_GETFPREGS: { /* Get the child FPU state. */
558 if (!access_ok(VERIFY_WRITE, datap,
559 sizeof(struct user_i387_struct))) {
560 ret = -EIO;
561 break;
562 }
563 ret = 0;
564 if (!tsk_used_math(child))
565 init_fpu(child);
566 get_fpregs((struct user_i387_struct __user *)data, child);
567 break;
568 }
569
570 case PTRACE_SETFPREGS: { /* Set the child FPU state. */
571 if (!access_ok(VERIFY_READ, datap,
572 sizeof(struct user_i387_struct))) {
573 ret = -EIO;
574 break;
575 }
576 set_stopped_child_used_math(child);
577 set_fpregs(child, (struct user_i387_struct __user *)data);
578 ret = 0;
579 break;
580 }
581
582 case PTRACE_GETFPXREGS: { /* Get the child extended FPU state. */
583 if (!access_ok(VERIFY_WRITE, datap,
584 sizeof(struct user_fxsr_struct))) {
585 ret = -EIO;
586 break;
587 }
588 if (!tsk_used_math(child))
589 init_fpu(child);
590 ret = get_fpxregs((struct user_fxsr_struct __user *)data, child);
591 break;
592 }
593
594 case PTRACE_SETFPXREGS: { /* Set the child extended FPU state. */
595 if (!access_ok(VERIFY_READ, datap,
596 sizeof(struct user_fxsr_struct))) {
597 ret = -EIO;
598 break;
599 }
600 set_stopped_child_used_math(child);
601 ret = set_fpxregs(child, (struct user_fxsr_struct __user *)data);
602 break;
603 }
604
605 case PTRACE_GET_THREAD_AREA:
606 ret = ptrace_get_thread_area(child, addr,
607 (struct user_desc __user *) data);
608 break;
609
610 case PTRACE_SET_THREAD_AREA:
611 ret = ptrace_set_thread_area(child, addr,
612 (struct user_desc __user *) data);
613 break;
614
615 default:
616 ret = ptrace_request(child, request, addr, data);
617 break;
618 }
481bed45 619 out_tsk:
1da177e4
LT
620 return ret;
621}
622
623void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
624{
625 struct siginfo info;
626
627 tsk->thread.trap_no = 1;
628 tsk->thread.error_code = error_code;
629
630 memset(&info, 0, sizeof(info));
631 info.si_signo = SIGTRAP;
632 info.si_code = TRAP_BRKPT;
633
634 /* User-mode eip? */
fa1e1bdf 635 info.si_addr = user_mode_vm(regs) ? (void __user *) regs->eip : NULL;
1da177e4
LT
636
637 /* Send us the fakey SIGTRAP */
638 force_sig_info(SIGTRAP, &info, tsk);
639}
640
641/* notification of system call entry/exit
642 * - triggered by current->work.syscall_trace
643 */
644__attribute__((regparm(3)))
ed75e8d5 645int do_syscall_trace(struct pt_regs *regs, int entryexit)
1da177e4 646{
4c7fc722
AA
647 int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU);
648 /*
649 * With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall
650 * interception
651 */
1b38f006 652 int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP);
4c7fc722 653 int ret = 0;
1b38f006 654
1da177e4 655 /* do the secure computing check first */
4c7fc722
AA
656 if (!entryexit)
657 secure_computing(regs->orig_eax);
1da177e4 658
ab1c23c2
BS
659 if (unlikely(current->audit_context)) {
660 if (entryexit)
5411be59 661 audit_syscall_exit(AUDITSC_RESULT(regs->eax),
4c7fc722 662 regs->eax);
ab1c23c2
BS
663 /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only
664 * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is
665 * not used, entry.S will call us only on syscall exit, not
666 * entry; so when TIF_SYSCALL_AUDIT is used we must avoid
667 * calling send_sigtrap() on syscall entry.
668 *
669 * Note that when PTRACE_SYSEMU_SINGLESTEP is used,
670 * is_singlestep is false, despite his name, so we will still do
671 * the correct thing.
672 */
673 else if (is_singlestep)
674 goto out;
675 }
1da177e4
LT
676
677 if (!(current->ptrace & PT_PTRACED))
2fd6f58b 678 goto out;
1da177e4 679
1b38f006
BS
680 /* If a process stops on the 1st tracepoint with SYSCALL_TRACE
681 * and then is resumed with SYSEMU_SINGLESTEP, it will come in
682 * here. We have to check this and return */
683 if (is_sysemu && entryexit)
684 return 0;
ed75e8d5 685
1da177e4 686 /* Fake a debug trap */
c8c86cec 687 if (is_singlestep)
1da177e4
LT
688 send_sigtrap(current, regs, 0);
689
c8c86cec 690 if (!test_thread_flag(TIF_SYSCALL_TRACE) && !is_sysemu)
2fd6f58b 691 goto out;
1da177e4
LT
692
693 /* the 0x80 provides a way for the tracing parent to distinguish
694 between a syscall stop and SIGTRAP delivery */
ed75e8d5 695 /* Note that the debugger could change the result of test_thread_flag!*/
4c7fc722 696 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80:0));
1da177e4
LT
697
698 /*
699 * this isn't the same as continuing with a signal, but it will do
700 * for normal use. strace only continues with a signal if the
701 * stopping signal is not SIGTRAP. -brl
702 */
703 if (current->exit_code) {
704 send_sig(current->exit_code, current, 1);
705 current->exit_code = 0;
706 }
ed75e8d5 707 ret = is_sysemu;
4c7fc722 708out:
2fd6f58b 709 if (unlikely(current->audit_context) && !entryexit)
5411be59 710 audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_eax,
2fd6f58b 711 regs->ebx, regs->ecx, regs->edx, regs->esi);
c8c86cec
BS
712 if (ret == 0)
713 return 0;
714
1b38f006 715 regs->orig_eax = -1; /* force skip of syscall restarting */
c8c86cec 716 if (unlikely(current->audit_context))
5411be59 717 audit_syscall_exit(AUDITSC_RESULT(regs->eax), regs->eax);
c8c86cec 718 return 1;
1da177e4 719}
This page took 0.273449 seconds and 5 git commands to generate.