2 * Server-side ptrace support
4 * Copyright (C) 1999 Alexandre Julliard
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
22 #include "wine/port.h"
30 #include <sys/types.h>
31 #ifdef HAVE_SYS_PTRACE_H
32 # include <sys/ptrace.h>
34 #ifdef HAVE_SYS_PARAM_H
35 # include <sys/param.h>
37 #ifdef HAVE_SYS_WAIT_H
38 # include <sys/wait.h>
40 #ifdef HAVE_SYS_SYSCALL_H
41 # include <sys/syscall.h>
44 # include <sys/ucontext.h>
50 #define WIN32_NO_STATUS
60 #define PTRACE_CONT PT_CONTINUE
62 #ifndef PTRACE_SINGLESTEP
63 #define PTRACE_SINGLESTEP PT_STEP
66 #define PTRACE_ATTACH PT_ATTACH
69 #define PTRACE_DETACH PT_DETACH
71 #ifndef PTRACE_PEEKDATA
72 #define PTRACE_PEEKDATA PT_READ_D
74 #ifndef PTRACE_POKEDATA
75 #define PTRACE_POKEDATA PT_WRITE_D
77 #ifndef PTRACE_PEEKUSER
78 #define PTRACE_PEEKUSER PT_READ_U
80 #ifndef PTRACE_POKEUSER
81 #define PTRACE_POKEUSER PT_WRITE_U
85 #define PTRACE_GETDBREGS PT_GETDBREGS
88 #define PTRACE_SETDBREGS PT_SETDBREGS
91 #ifndef HAVE_SYS_PTRACE_H
98 static inline int ptrace(int req, ...) { errno = EPERM; return -1; /*FAIL*/ }
99 #endif /* HAVE_SYS_PTRACE_H */
105 /* handle a status returned by waitpid */
106 static int handle_child_status( struct thread *thread, int pid, int status, int want_sig )
108 if (WIFSTOPPED(status))
110 int sig = WSTOPSIG(status);
111 if (debug_level && thread)
112 fprintf( stderr, "%04x: *signal* signal=%d\n", thread->id, sig );
115 /* ignore other signals for now */
116 ptrace( PTRACE_CONT, pid, (caddr_t)1, sig );
120 if (thread && (WIFSIGNALED(status) || WIFEXITED(status)))
122 thread->unix_pid = -1;
123 thread->unix_tid = -1;
126 if (WIFSIGNALED(status))
127 fprintf( stderr, "%04x: *exited* signal=%d\n",
128 thread->id, WTERMSIG(status) );
130 fprintf( stderr, "%04x: *exited* status=%d\n",
131 thread->id, WEXITSTATUS(status) );
137 /* handle a SIGCHLD signal */
138 void sigchld_callback(void)
144 if (!(pid = waitpid( -1, &status, WUNTRACED | WNOHANG | __WALL ))) break;
147 struct thread *thread = get_thread_from_tid( pid );
148 if (!thread) thread = get_thread_from_pid( pid );
149 handle_child_status( thread, pid, status, -1 );
155 /* return the Unix pid to use in ptrace calls for a given process */
156 static int get_ptrace_pid( struct thread *thread )
158 #ifdef linux /* linux always uses thread id */
159 if (thread->unix_tid != -1) return thread->unix_tid;
161 return thread->unix_pid;
164 /* return the Unix tid to use in ptrace calls for a given thread */
165 static int get_ptrace_tid( struct thread *thread )
167 if (thread->unix_tid != -1) return thread->unix_tid;
168 return thread->unix_pid;
171 /* wait for a ptraced child to get a certain signal */
172 static int waitpid_thread( struct thread *thread, int signal )
179 if ((res = waitpid( get_ptrace_pid(thread), &status, WUNTRACED | __WALL )) == -1)
183 if (!watchdog_triggered()) continue;
184 if (debug_level) fprintf( stderr, "%04x: *watchdog* waitpid aborted\n", thread->id );
186 else if (errno == ECHILD) /* must have died */
188 thread->unix_pid = -1;
189 thread->unix_tid = -1;
191 else perror( "waitpid" );
195 res = handle_child_status( thread, res, status, signal );
196 if (!res || res == signal) break;
199 return (thread->unix_pid != -1);
202 /* send a signal to a specific thread */
203 static inline int tkill( int tgid, int pid, int sig )
206 int ret = syscall( __NR_tgkill, tgid, pid, sig );
207 if (ret < 0 && errno == ENOSYS) ret = syscall( __NR_tkill, pid, sig );
209 #elif (defined(__FreeBSD__) || defined (__FreeBSD_kernel__)) && defined(HAVE_THR_KILL2)
210 return thr_kill2( tgid, pid, sig );
217 /* initialize the process tracing mechanism */
218 void init_tracing_mechanism(void)
220 /* no initialization needed for ptrace */
223 /* initialize the per-process tracing mechanism */
224 void init_process_tracing( struct process *process )
226 /* ptrace setup is done on-demand */
229 /* terminate the per-process tracing mechanism */
230 void finish_process_tracing( struct process *process )
234 /* send a Unix signal to a specific thread */
235 int send_thread_signal( struct thread *thread, int sig )
239 if (thread->unix_pid != -1)
241 if (thread->unix_tid != -1)
243 ret = tkill( thread->unix_pid, thread->unix_tid, sig );
244 if (ret == -1 && errno == ENOSYS) ret = kill( thread->unix_pid, sig );
246 else ret = kill( thread->unix_pid, sig );
248 if (ret == -1 && errno == ESRCH) /* thread got killed */
250 thread->unix_pid = -1;
251 thread->unix_tid = -1;
254 if (debug_level && ret != -1)
255 fprintf( stderr, "%04x: *sent signal* signal=%d\n", thread->id, sig );
259 /* resume a thread after we have used ptrace on it */
260 static void resume_after_ptrace( struct thread *thread )
262 if (thread->unix_pid == -1) return;
263 if (ptrace( PTRACE_DETACH, get_ptrace_pid(thread), (caddr_t)1, 0 ) == -1)
265 if (errno == ESRCH) thread->unix_pid = thread->unix_tid = -1; /* thread got killed */
269 /* suspend a thread to allow using ptrace on it */
270 /* you must do a resume_after_ptrace when finished with the thread */
271 static int suspend_for_ptrace( struct thread *thread )
273 /* can't stop a thread while initialisation is in progress */
274 if (thread->unix_pid == -1 || !is_process_init_done(thread->process)) goto error;
276 /* this may fail if the client is already being debugged */
277 if (ptrace( PTRACE_ATTACH, get_ptrace_pid(thread), 0, 0 ) == -1)
279 if (errno == ESRCH) thread->unix_pid = thread->unix_tid = -1; /* thread got killed */
282 if (waitpid_thread( thread, SIGSTOP )) return 1;
283 resume_after_ptrace( thread );
285 set_error( STATUS_ACCESS_DENIED );
289 /* read a long from a thread address space */
290 static long read_thread_long( struct thread *thread, long *addr, long *data )
293 *data = ptrace( PTRACE_PEEKDATA, get_ptrace_pid(thread), (caddr_t)addr, 0 );
294 if ( *data == -1 && errno)
302 /* write a long to a thread address space */
303 static long write_thread_long( struct thread *thread, long *addr, long data, unsigned long mask )
308 if (read_thread_long( thread, addr, &res ) == -1) return -1;
309 data = (data & mask) | (res & ~mask);
311 if ((res = ptrace( PTRACE_POKEDATA, get_ptrace_pid(thread), (caddr_t)addr, data )) == -1)
316 /* return a thread of the process suitable for ptracing */
317 static struct thread *get_ptrace_thread( struct process *process )
319 struct thread *thread;
321 LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )
323 if (thread->unix_pid != -1) return thread;
325 set_error( STATUS_ACCESS_DENIED ); /* process is dead */
329 /* read data from a process memory space */
330 int read_process_memory( struct process *process, client_ptr_t ptr, data_size_t size, char *dest )
332 struct thread *thread = get_ptrace_thread( process );
333 unsigned int first_offset, last_offset, len;
336 if (!thread) return 0;
338 if ((unsigned long)ptr != ptr)
340 set_error( STATUS_ACCESS_DENIED );
344 first_offset = ptr % sizeof(long);
345 last_offset = (size + first_offset) % sizeof(long);
346 if (!last_offset) last_offset = sizeof(long);
348 addr = (long *)(unsigned long)(ptr - first_offset);
349 len = (size + first_offset + sizeof(long) - 1) / sizeof(long);
351 if (suspend_for_ptrace( thread ))
353 if (len > 3) /* /proc/pid/mem should be faster for large sizes */
358 sprintf( procmem, "/proc/%u/mem", process->unix_pid );
359 if ((fd = open( procmem, O_RDONLY )) != -1)
361 ssize_t ret = pread( fd, dest, size, ptr );
373 if (read_thread_long( thread, addr++, &data ) == -1) goto done;
374 memcpy( dest, (char *)&data + first_offset, sizeof(long) - first_offset );
375 dest += sizeof(long) - first_offset;
382 if (read_thread_long( thread, addr++, &data ) == -1) goto done;
383 memcpy( dest, &data, sizeof(long) );
384 dest += sizeof(long);
388 if (read_thread_long( thread, addr++, &data ) == -1) goto done;
389 memcpy( dest, (char *)&data + first_offset, last_offset - first_offset );
393 resume_after_ptrace( thread );
398 /* make sure we can write to the whole address range */
399 /* len is the total size (in ints) */
400 static int check_process_write_access( struct thread *thread, long *addr, data_size_t len )
402 int page = get_page_size() / sizeof(int);
406 if (write_thread_long( thread, addr, 0, 0 ) == -1) return 0;
407 if (len <= page) break;
411 return (write_thread_long( thread, addr + len - 1, 0, 0 ) != -1);
414 /* write data to a process memory space */
415 int write_process_memory( struct process *process, client_ptr_t ptr, data_size_t size, const char *src )
417 struct thread *thread = get_ptrace_thread( process );
422 unsigned long first_mask, first_offset, last_mask, last_offset;
424 if (!thread) return 0;
426 if ((unsigned long)ptr != ptr)
428 set_error( STATUS_ACCESS_DENIED );
432 /* compute the mask for the first long */
434 first_offset = ptr % sizeof(long);
435 memset( &first_mask, 0, first_offset );
437 /* compute the mask for the last long */
438 last_offset = (size + first_offset) % sizeof(long);
439 if (!last_offset) last_offset = sizeof(long);
441 memset( &last_mask, 0xff, last_offset );
443 addr = (long *)(unsigned long)(ptr - first_offset);
444 len = (size + first_offset + sizeof(long) - 1) / sizeof(long);
446 if (suspend_for_ptrace( thread ))
448 if (!check_process_write_access( thread, addr, len ))
450 set_error( STATUS_ACCESS_DENIED );
459 sprintf( procmem, "/proc/%u/mem", process->unix_pid );
460 if ((fd = open( procmem, O_WRONLY )) != -1)
462 ssize_t r = pwrite( fd, src, size, ptr );
472 /* first word is special */
475 memcpy( (char *)&data + first_offset, src, sizeof(long) - first_offset );
476 src += sizeof(long) - first_offset;
477 if (write_thread_long( thread, addr++, data, first_mask ) == -1) goto done;
481 else last_mask &= first_mask;
485 memcpy( &data, src, sizeof(long) );
487 if (write_thread_long( thread, addr++, data, ~0ul ) == -1) goto done;
491 /* last word is special too */
492 memcpy( (char *)&data + first_offset, src, last_offset - first_offset );
493 if (write_thread_long( thread, addr, data, last_mask ) == -1) goto done;
497 resume_after_ptrace( thread );
502 /* retrieve an LDT selector entry */
503 void get_selector_entry( struct thread *thread, int entry, unsigned int *base,
504 unsigned int *limit, unsigned char *flags )
506 if (!thread->process->ldt_copy)
508 set_error( STATUS_ACCESS_DENIED );
513 set_error( STATUS_ACCESS_VIOLATION );
516 if (suspend_for_ptrace( thread ))
518 unsigned char flags_buf[sizeof(long)];
519 long *addr = (long *)(unsigned long)thread->process->ldt_copy + entry;
520 if (read_thread_long( thread, addr, (long *)base ) == -1) goto done;
521 if (read_thread_long( thread, addr + 8192, (long *)limit ) == -1) goto done;
522 addr = (long *)(unsigned long)thread->process->ldt_copy + 2*8192 + (entry / sizeof(long));
523 if (read_thread_long( thread, addr, (long *)flags_buf ) == -1) goto done;
524 *flags = flags_buf[entry % sizeof(long)];
526 resume_after_ptrace( thread );
531 #if defined(linux) && defined(HAVE_SYS_USER_H) && (defined(__i386__) || defined(__x86_64__))
533 #include <sys/user.h>
535 /* debug register offset in struct user */
536 #define DR_OFFSET(dr) ((((struct user *)0)->u_debugreg) + (dr))
538 /* retrieve the thread x86 registers */
539 void get_thread_context( struct thread *thread, context_t *context, unsigned int flags )
541 int i, pid = get_ptrace_tid(thread);
544 /* all other regs are handled on the client side */
545 assert( flags == SERVER_CTX_DEBUG_REGISTERS );
547 if (!suspend_for_ptrace( thread )) return;
549 for (i = 0; i < 8; i++)
551 if (i == 4 || i == 5) continue;
553 data[i] = ptrace( PTRACE_PEEKUSER, pid, DR_OFFSET(i), 0 );
554 if ((data[i] == -1) && errno)
560 switch (context->cpu)
563 context->debug.i386_regs.dr0 = data[0];
564 context->debug.i386_regs.dr1 = data[1];
565 context->debug.i386_regs.dr2 = data[2];
566 context->debug.i386_regs.dr3 = data[3];
567 context->debug.i386_regs.dr6 = data[6];
568 context->debug.i386_regs.dr7 = data[7];
571 context->debug.x86_64_regs.dr0 = data[0];
572 context->debug.x86_64_regs.dr1 = data[1];
573 context->debug.x86_64_regs.dr2 = data[2];
574 context->debug.x86_64_regs.dr3 = data[3];
575 context->debug.x86_64_regs.dr6 = data[6];
576 context->debug.x86_64_regs.dr7 = data[7];
579 set_error( STATUS_INVALID_PARAMETER );
582 context->flags |= SERVER_CTX_DEBUG_REGISTERS;
584 resume_after_ptrace( thread );
587 /* set the thread x86 registers */
588 void set_thread_context( struct thread *thread, const context_t *context, unsigned int flags )
590 int pid = get_ptrace_tid( thread );
592 /* all other regs are handled on the client side */
593 assert( flags == SERVER_CTX_DEBUG_REGISTERS );
595 if (!suspend_for_ptrace( thread )) return;
597 switch (context->cpu)
600 /* Linux 2.6.33+ does DR0-DR3 alignment validation, so it has to know LEN bits first */
601 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(7), context->debug.i386_regs.dr7 & 0xffff0000 ) == -1) goto error;
602 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(0), context->debug.i386_regs.dr0 ) == -1) goto error;
603 if (thread->context) thread->context->debug.i386_regs.dr0 = context->debug.i386_regs.dr0;
604 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(1), context->debug.i386_regs.dr1 ) == -1) goto error;
605 if (thread->context) thread->context->debug.i386_regs.dr1 = context->debug.i386_regs.dr1;
606 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(2), context->debug.i386_regs.dr2 ) == -1) goto error;
607 if (thread->context) thread->context->debug.i386_regs.dr2 = context->debug.i386_regs.dr2;
608 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(3), context->debug.i386_regs.dr3 ) == -1) goto error;
609 if (thread->context) thread->context->debug.i386_regs.dr3 = context->debug.i386_regs.dr3;
610 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(6), context->debug.i386_regs.dr6 ) == -1) goto error;
611 if (thread->context) thread->context->debug.i386_regs.dr6 = context->debug.i386_regs.dr6;
612 /* Linux 2.6.33+ needs enable bits set briefly to update value returned by PEEKUSER later */
613 ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(7), context->debug.i386_regs.dr7 | 0x55 );
614 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(7), context->debug.i386_regs.dr7 ) == -1) goto error;
615 if (thread->context) thread->context->debug.i386_regs.dr7 = context->debug.i386_regs.dr7;
618 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(7), context->debug.x86_64_regs.dr7 & 0xffff0000 ) == -1) goto error;
619 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(0), context->debug.x86_64_regs.dr0 ) == -1) goto error;
620 if (thread->context) thread->context->debug.x86_64_regs.dr0 = context->debug.x86_64_regs.dr0;
621 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(1), context->debug.x86_64_regs.dr1 ) == -1) goto error;
622 if (thread->context) thread->context->debug.x86_64_regs.dr1 = context->debug.x86_64_regs.dr1;
623 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(2), context->debug.x86_64_regs.dr2 ) == -1) goto error;
624 if (thread->context) thread->context->debug.x86_64_regs.dr2 = context->debug.x86_64_regs.dr2;
625 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(3), context->debug.x86_64_regs.dr3 ) == -1) goto error;
626 if (thread->context) thread->context->debug.x86_64_regs.dr3 = context->debug.x86_64_regs.dr3;
627 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(6), context->debug.x86_64_regs.dr6 ) == -1) goto error;
628 if (thread->context) thread->context->debug.x86_64_regs.dr6 = context->debug.x86_64_regs.dr6;
629 ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(7), context->debug.x86_64_regs.dr7 | 0x55 );
630 if (ptrace( PTRACE_POKEUSER, pid, DR_OFFSET(7), context->debug.x86_64_regs.dr7 ) == -1) goto error;
631 if (thread->context) thread->context->debug.x86_64_regs.dr7 = context->debug.x86_64_regs.dr7;
634 set_error( STATUS_INVALID_PARAMETER );
636 resume_after_ptrace( thread );
640 resume_after_ptrace( thread );
643 #elif defined(__i386__) && defined(PTRACE_GETDBREGS) && defined(PTRACE_SETDBREGS) && \
644 (defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__) || defined(__NetBSD__) || defined(__DragonFly__))
646 #include <machine/reg.h>
648 /* retrieve the thread x86 registers */
649 void get_thread_context( struct thread *thread, context_t *context, unsigned int flags )
651 int pid = get_ptrace_tid(thread);
654 /* all other regs are handled on the client side */
655 assert( flags == SERVER_CTX_DEBUG_REGISTERS );
657 if (!suspend_for_ptrace( thread )) return;
659 if (ptrace( PTRACE_GETDBREGS, pid, (caddr_t) &dbregs, 0 ) == -1) file_set_error();
663 /* needed for FreeBSD, the structure fields have changed under 5.x */
664 context->debug.i386_regs.dr0 = DBREG_DRX((&dbregs), 0);
665 context->debug.i386_regs.dr1 = DBREG_DRX((&dbregs), 1);
666 context->debug.i386_regs.dr2 = DBREG_DRX((&dbregs), 2);
667 context->debug.i386_regs.dr3 = DBREG_DRX((&dbregs), 3);
668 context->debug.i386_regs.dr6 = DBREG_DRX((&dbregs), 6);
669 context->debug.i386_regs.dr7 = DBREG_DRX((&dbregs), 7);
671 context->debug.i386_regs.dr0 = dbregs.dr0;
672 context->debug.i386_regs.dr1 = dbregs.dr1;
673 context->debug.i386_regs.dr2 = dbregs.dr2;
674 context->debug.i386_regs.dr3 = dbregs.dr3;
675 context->debug.i386_regs.dr6 = dbregs.dr6;
676 context->debug.i386_regs.dr7 = dbregs.dr7;
678 context->flags |= SERVER_CTX_DEBUG_REGISTERS;
680 resume_after_ptrace( thread );
683 /* set the thread x86 registers */
684 void set_thread_context( struct thread *thread, const context_t *context, unsigned int flags )
686 int pid = get_ptrace_tid(thread);
689 /* all other regs are handled on the client side */
690 assert( flags == SERVER_CTX_DEBUG_REGISTERS );
692 if (!suspend_for_ptrace( thread )) return;
695 /* needed for FreeBSD, the structure fields have changed under 5.x */
696 DBREG_DRX((&dbregs), 0) = context->debug.i386_regs.dr0;
697 DBREG_DRX((&dbregs), 1) = context->debug.i386_regs.dr1;
698 DBREG_DRX((&dbregs), 2) = context->debug.i386_regs.dr2;
699 DBREG_DRX((&dbregs), 3) = context->debug.i386_regs.dr3;
700 DBREG_DRX((&dbregs), 4) = 0;
701 DBREG_DRX((&dbregs), 5) = 0;
702 DBREG_DRX((&dbregs), 6) = context->debug.i386_regs.dr6;
703 DBREG_DRX((&dbregs), 7) = context->debug.i386_regs.dr7;
705 dbregs.dr0 = context->debug.i386_regs.dr0;
706 dbregs.dr1 = context->debug.i386_regs.dr1;
707 dbregs.dr2 = context->debug.i386_regs.dr2;
708 dbregs.dr3 = context->debug.i386_regs.dr3;
711 dbregs.dr6 = context->debug.i386_regs.dr6;
712 dbregs.dr7 = context->debug.i386_regs.dr7;
714 if (ptrace( PTRACE_SETDBREGS, pid, (caddr_t) &dbregs, 0 ) == -1) file_set_error();
715 else if (thread->context)
716 thread->context->debug.i386_regs = context->debug.i386_regs; /* update the cached values */
717 resume_after_ptrace( thread );
720 #else /* linux || __FreeBSD__ */
722 /* retrieve the thread x86 registers */
723 void get_thread_context( struct thread *thread, context_t *context, unsigned int flags )
727 /* set the thread x86 debug registers */
728 void set_thread_context( struct thread *thread, const context_t *context, unsigned int flags )
732 #endif /* linux || __FreeBSD__ */
734 #endif /* USE_PTRACE */