11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/kernel/ptrace.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * (C) Copyright 1999 Linus Torvalds 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * Common interfaces for "ptrace()" which we do not want 71da177e4SLinus Torvalds * to continually duplicate across every architecture. 81da177e4SLinus Torvalds */ 91da177e4SLinus Torvalds 10c59ede7bSRandy.Dunlap #include <linux/capability.h> 111da177e4SLinus Torvalds #include <linux/module.h> 121da177e4SLinus Torvalds #include <linux/sched.h> 131da177e4SLinus Torvalds #include <linux/errno.h> 141da177e4SLinus Torvalds #include <linux/mm.h> 151da177e4SLinus Torvalds #include <linux/highmem.h> 161da177e4SLinus Torvalds #include <linux/pagemap.h> 171da177e4SLinus Torvalds #include <linux/smp_lock.h> 181da177e4SLinus Torvalds #include <linux/ptrace.h> 191da177e4SLinus Torvalds #include <linux/security.h> 207ed20e1aSJesper Juhl #include <linux/signal.h> 21a5cb013dSAl Viro #include <linux/audit.h> 22b488893aSPavel Emelyanov #include <linux/pid_namespace.h> 23f17d30a8SAdrian Bunk #include <linux/syscalls.h> 243a709703SRoland McGrath #include <linux/uaccess.h> 251da177e4SLinus Torvalds 26bf53de90SMarkus Metzger 27bf53de90SMarkus Metzger /* 28bf53de90SMarkus Metzger * Initialize a new task whose father had been ptraced. 29bf53de90SMarkus Metzger * 30bf53de90SMarkus Metzger * Called from copy_process(). 31bf53de90SMarkus Metzger */ 32bf53de90SMarkus Metzger void ptrace_fork(struct task_struct *child, unsigned long clone_flags) 33bf53de90SMarkus Metzger { 34bf53de90SMarkus Metzger arch_ptrace_fork(child, clone_flags); 35bf53de90SMarkus Metzger } 36bf53de90SMarkus Metzger 371da177e4SLinus Torvalds /* 381da177e4SLinus Torvalds * ptrace a task: make the debugger its new parent and 391da177e4SLinus Torvalds * move it to the ptrace list. 401da177e4SLinus Torvalds * 411da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 421da177e4SLinus Torvalds */ 4336c8b586SIngo Molnar void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) 441da177e4SLinus Torvalds { 45f470021aSRoland McGrath BUG_ON(!list_empty(&child->ptrace_entry)); 46f470021aSRoland McGrath list_add(&child->ptrace_entry, &new_parent->ptraced); 471da177e4SLinus Torvalds child->parent = new_parent; 481da177e4SLinus Torvalds } 491da177e4SLinus Torvalds 501da177e4SLinus Torvalds /* 511da177e4SLinus Torvalds * Turn a tracing stop into a normal stop now, since with no tracer there 521da177e4SLinus Torvalds * would be no way to wake it up with SIGCONT or SIGKILL. If there was a 531da177e4SLinus Torvalds * signal sent that would resume the child, but didn't because it was in 541da177e4SLinus Torvalds * TASK_TRACED, resume it now. 551da177e4SLinus Torvalds * Requires that irqs be disabled. 561da177e4SLinus Torvalds */ 57b747c8c1SAdrian Bunk static void ptrace_untrace(struct task_struct *child) 581da177e4SLinus Torvalds { 591da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 606618a3e2SMatthew Wilcox if (task_is_traced(child)) { 611ee11844SOleg Nesterov /* 621ee11844SOleg Nesterov * If the group stop is completed or in progress, 631ee11844SOleg Nesterov * this thread was already counted as stopped. 641ee11844SOleg Nesterov */ 651ee11844SOleg Nesterov if (child->signal->flags & SIGNAL_STOP_STOPPED || 661ee11844SOleg Nesterov child->signal->group_stop_count) 67d9ae90acSOleg Nesterov __set_task_state(child, TASK_STOPPED); 681ee11844SOleg Nesterov else 691da177e4SLinus Torvalds signal_wake_up(child, 1); 701da177e4SLinus Torvalds } 711da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 721da177e4SLinus Torvalds } 731da177e4SLinus Torvalds 741da177e4SLinus Torvalds /* 751da177e4SLinus Torvalds * unptrace a task: move it back to its original parent and 761da177e4SLinus Torvalds * remove it from the ptrace list. 771da177e4SLinus Torvalds * 781da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 791da177e4SLinus Torvalds */ 8036c8b586SIngo Molnar void __ptrace_unlink(struct task_struct *child) 811da177e4SLinus Torvalds { 825ecfbae0SOleg Nesterov BUG_ON(!child->ptrace); 835ecfbae0SOleg Nesterov 841da177e4SLinus Torvalds child->ptrace = 0; 851da177e4SLinus Torvalds child->parent = child->real_parent; 86f470021aSRoland McGrath list_del_init(&child->ptrace_entry); 871da177e4SLinus Torvalds 88bf53de90SMarkus Metzger arch_ptrace_untrace(child); 896618a3e2SMatthew Wilcox if (task_is_traced(child)) 901da177e4SLinus Torvalds ptrace_untrace(child); 911da177e4SLinus Torvalds } 921da177e4SLinus Torvalds 931da177e4SLinus Torvalds /* 941da177e4SLinus Torvalds * Check that we have indeed attached to the thing.. 951da177e4SLinus Torvalds */ 961da177e4SLinus Torvalds int ptrace_check_attach(struct task_struct *child, int kill) 971da177e4SLinus Torvalds { 981da177e4SLinus Torvalds int ret = -ESRCH; 991da177e4SLinus Torvalds 1001da177e4SLinus Torvalds /* 1011da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 1021da177e4SLinus Torvalds * possible race where someone else was tracing our child and 1031da177e4SLinus Torvalds * detached between these two checks. After this locked check, 1041da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 1051da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 1061da177e4SLinus Torvalds */ 1071da177e4SLinus Torvalds read_lock(&tasklist_lock); 108c0c0b649SOleg Nesterov if ((child->ptrace & PT_PTRACED) && child->parent == current) { 1091da177e4SLinus Torvalds ret = 0; 110c0c0b649SOleg Nesterov /* 111c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 112c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 113c0c0b649SOleg Nesterov */ 1141da177e4SLinus Torvalds spin_lock_irq(&child->sighand->siglock); 115d9ae90acSOleg Nesterov if (task_is_stopped(child)) 1161da177e4SLinus Torvalds child->state = TASK_TRACED; 117d9ae90acSOleg Nesterov else if (!task_is_traced(child) && !kill) 1181da177e4SLinus Torvalds ret = -ESRCH; 1191da177e4SLinus Torvalds spin_unlock_irq(&child->sighand->siglock); 1201da177e4SLinus Torvalds } 1211da177e4SLinus Torvalds read_unlock(&tasklist_lock); 1221da177e4SLinus Torvalds 123d9ae90acSOleg Nesterov if (!ret && !kill) 12485ba2d86SRoland McGrath ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; 1251da177e4SLinus Torvalds 1261da177e4SLinus Torvalds /* All systems go.. */ 1271da177e4SLinus Torvalds return ret; 1281da177e4SLinus Torvalds } 1291da177e4SLinus Torvalds 130006ebb40SStephen Smalley int __ptrace_may_access(struct task_struct *task, unsigned int mode) 131ab8d11beSMiklos Szeredi { 132c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 133b6dff3ecSDavid Howells 134df26c40eSEric W. Biederman /* May we inspect the given task? 135df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 136df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 137df26c40eSEric W. Biederman * 138df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 139df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 140df26c40eSEric W. Biederman * or halting the specified task is impossible. 141df26c40eSEric W. Biederman */ 142df26c40eSEric W. Biederman int dumpable = 0; 143df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 144df26c40eSEric W. Biederman if (task == current) 145df26c40eSEric W. Biederman return 0; 146c69e8d9cSDavid Howells rcu_read_lock(); 147c69e8d9cSDavid Howells tcred = __task_cred(task); 148c69e8d9cSDavid Howells if ((cred->uid != tcred->euid || 149c69e8d9cSDavid Howells cred->uid != tcred->suid || 150c69e8d9cSDavid Howells cred->uid != tcred->uid || 151c69e8d9cSDavid Howells cred->gid != tcred->egid || 152c69e8d9cSDavid Howells cred->gid != tcred->sgid || 153c69e8d9cSDavid Howells cred->gid != tcred->gid) && 154c69e8d9cSDavid Howells !capable(CAP_SYS_PTRACE)) { 155c69e8d9cSDavid Howells rcu_read_unlock(); 156ab8d11beSMiklos Szeredi return -EPERM; 157c69e8d9cSDavid Howells } 158c69e8d9cSDavid Howells rcu_read_unlock(); 159ab8d11beSMiklos Szeredi smp_rmb(); 160df26c40eSEric W. Biederman if (task->mm) 1616c5d5238SKawai, Hidehiro dumpable = get_dumpable(task->mm); 162df26c40eSEric W. Biederman if (!dumpable && !capable(CAP_SYS_PTRACE)) 163ab8d11beSMiklos Szeredi return -EPERM; 164ab8d11beSMiklos Szeredi 1655cd9c58fSDavid Howells return security_ptrace_may_access(task, mode); 166ab8d11beSMiklos Szeredi } 167ab8d11beSMiklos Szeredi 168006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 169ab8d11beSMiklos Szeredi { 170ab8d11beSMiklos Szeredi int err; 171ab8d11beSMiklos Szeredi task_lock(task); 172006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 173ab8d11beSMiklos Szeredi task_unlock(task); 1743a709703SRoland McGrath return !err; 175ab8d11beSMiklos Szeredi } 176ab8d11beSMiklos Szeredi 1771da177e4SLinus Torvalds int ptrace_attach(struct task_struct *task) 1781da177e4SLinus Torvalds { 1791da177e4SLinus Torvalds int retval; 1806175ecfeSSripathi Kodi unsigned long flags; 181f5b40e36SLinus Torvalds 182a5cb013dSAl Viro audit_ptrace(task); 183a5cb013dSAl Viro 1841da177e4SLinus Torvalds retval = -EPERM; 185bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 186f5b40e36SLinus Torvalds goto out; 187f5b40e36SLinus Torvalds 188d84f4f99SDavid Howells /* Protect exec's credential calculations against our interference; 189d84f4f99SDavid Howells * SUID, SGID and LSM creds get determined differently under ptrace. 190d84f4f99SDavid Howells */ 191d84f4f99SDavid Howells retval = mutex_lock_interruptible(¤t->cred_exec_mutex); 192d84f4f99SDavid Howells if (retval < 0) 193d84f4f99SDavid Howells goto out; 194d84f4f99SDavid Howells 195d84f4f99SDavid Howells retval = -EPERM; 196f358166aSLinus Torvalds repeat: 197f358166aSLinus Torvalds /* 198f358166aSLinus Torvalds * Nasty, nasty. 199f358166aSLinus Torvalds * 200f358166aSLinus Torvalds * We want to hold both the task-lock and the 201f358166aSLinus Torvalds * tasklist_lock for writing at the same time. 202f358166aSLinus Torvalds * But that's against the rules (tasklist_lock 203f358166aSLinus Torvalds * is taken for reading by interrupts on other 204f358166aSLinus Torvalds * cpu's that may have task_lock). 205f358166aSLinus Torvalds */ 206f5b40e36SLinus Torvalds task_lock(task); 2076175ecfeSSripathi Kodi if (!write_trylock_irqsave(&tasklist_lock, flags)) { 208f358166aSLinus Torvalds task_unlock(task); 209f358166aSLinus Torvalds do { 210f358166aSLinus Torvalds cpu_relax(); 211f358166aSLinus Torvalds } while (!write_can_lock(&tasklist_lock)); 212f358166aSLinus Torvalds goto repeat; 213f358166aSLinus Torvalds } 214f5b40e36SLinus Torvalds 215df26c40eSEric W. Biederman if (!task->mm) 216df26c40eSEric W. Biederman goto bad; 2171da177e4SLinus Torvalds /* the same process cannot be attached many times */ 2181da177e4SLinus Torvalds if (task->ptrace & PT_PTRACED) 2191da177e4SLinus Torvalds goto bad; 220006ebb40SStephen Smalley retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); 2211da177e4SLinus Torvalds if (retval) 2221da177e4SLinus Torvalds goto bad; 2231da177e4SLinus Torvalds 2241da177e4SLinus Torvalds /* Go */ 2256b39c7bfSOleg Nesterov task->ptrace |= PT_PTRACED; 2261da177e4SLinus Torvalds if (capable(CAP_SYS_PTRACE)) 2271da177e4SLinus Torvalds task->ptrace |= PT_PTRACE_CAP; 2281da177e4SLinus Torvalds 2291da177e4SLinus Torvalds __ptrace_link(task, current); 2301da177e4SLinus Torvalds 23133e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 2321da177e4SLinus Torvalds bad: 2336175ecfeSSripathi Kodi write_unlock_irqrestore(&tasklist_lock, flags); 2341da177e4SLinus Torvalds task_unlock(task); 235d84f4f99SDavid Howells mutex_unlock(¤t->cred_exec_mutex); 236f5b40e36SLinus Torvalds out: 2371da177e4SLinus Torvalds return retval; 2381da177e4SLinus Torvalds } 2391da177e4SLinus Torvalds 24039c626aeSOleg Nesterov /* 24139c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 24239c626aeSOleg Nesterov */ 24339c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 24439c626aeSOleg Nesterov { 24539c626aeSOleg Nesterov int ret; 24639c626aeSOleg Nesterov spin_lock(&sigh->siglock); 24739c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 24839c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 24939c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 25039c626aeSOleg Nesterov return ret; 25139c626aeSOleg Nesterov } 25239c626aeSOleg Nesterov 25339c626aeSOleg Nesterov /* 25439c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 25539c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 25639c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 25739c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 25839c626aeSOleg Nesterov * 25939c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 26039c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 26139c626aeSOleg Nesterov * If it should reap itself, return true. 26239c626aeSOleg Nesterov * 26339c626aeSOleg Nesterov * If it's our own child, there is no notification to do. 26439c626aeSOleg Nesterov * But if our normal children self-reap, then this child 26539c626aeSOleg Nesterov * was prevented by ptrace and we must reap it now. 26639c626aeSOleg Nesterov */ 26739c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 26839c626aeSOleg Nesterov { 26939c626aeSOleg Nesterov __ptrace_unlink(p); 27039c626aeSOleg Nesterov 27139c626aeSOleg Nesterov if (p->exit_state == EXIT_ZOMBIE) { 27239c626aeSOleg Nesterov if (!task_detached(p) && thread_group_empty(p)) { 27339c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 27439c626aeSOleg Nesterov do_notify_parent(p, p->exit_signal); 27539c626aeSOleg Nesterov else if (ignoring_children(tracer->sighand)) 27639c626aeSOleg Nesterov p->exit_signal = -1; 27739c626aeSOleg Nesterov } 27839c626aeSOleg Nesterov if (task_detached(p)) { 27939c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 28039c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 28139c626aeSOleg Nesterov return true; 28239c626aeSOleg Nesterov } 28339c626aeSOleg Nesterov } 28439c626aeSOleg Nesterov 28539c626aeSOleg Nesterov return false; 28639c626aeSOleg Nesterov } 28739c626aeSOleg Nesterov 2881da177e4SLinus Torvalds int ptrace_detach(struct task_struct *child, unsigned int data) 2891da177e4SLinus Torvalds { 29039c626aeSOleg Nesterov bool dead = false; 2914576145cSOleg Nesterov 2927ed20e1aSJesper Juhl if (!valid_signal(data)) 2931da177e4SLinus Torvalds return -EIO; 2941da177e4SLinus Torvalds 2951da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 2961da177e4SLinus Torvalds ptrace_disable(child); 2977d941432SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 2981da177e4SLinus Torvalds 29995c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 30039c626aeSOleg Nesterov /* 30139c626aeSOleg Nesterov * This child can be already killed. Make sure de_thread() or 30239c626aeSOleg Nesterov * our sub-thread doing do_wait() didn't do release_task() yet. 30339c626aeSOleg Nesterov */ 30495c3eb76SOleg Nesterov if (child->ptrace) { 30595c3eb76SOleg Nesterov child->exit_code = data; 3064576145cSOleg Nesterov dead = __ptrace_detach(current, child); 30795c3eb76SOleg Nesterov } 3081da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 3091da177e4SLinus Torvalds 3104576145cSOleg Nesterov if (unlikely(dead)) 3114576145cSOleg Nesterov release_task(child); 3124576145cSOleg Nesterov 3131da177e4SLinus Torvalds return 0; 3141da177e4SLinus Torvalds } 3151da177e4SLinus Torvalds 31639c626aeSOleg Nesterov /* 31739c626aeSOleg Nesterov * Detach all tasks we were using ptrace on. 31839c626aeSOleg Nesterov */ 31939c626aeSOleg Nesterov void exit_ptrace(struct task_struct *tracer) 32039c626aeSOleg Nesterov { 32139c626aeSOleg Nesterov struct task_struct *p, *n; 32239c626aeSOleg Nesterov LIST_HEAD(ptrace_dead); 32339c626aeSOleg Nesterov 32439c626aeSOleg Nesterov write_lock_irq(&tasklist_lock); 32539c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 32639c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 32739c626aeSOleg Nesterov list_add(&p->ptrace_entry, &ptrace_dead); 32839c626aeSOleg Nesterov } 32939c626aeSOleg Nesterov write_unlock_irq(&tasklist_lock); 33039c626aeSOleg Nesterov 33139c626aeSOleg Nesterov BUG_ON(!list_empty(&tracer->ptraced)); 33239c626aeSOleg Nesterov 33339c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { 33439c626aeSOleg Nesterov list_del_init(&p->ptrace_entry); 33539c626aeSOleg Nesterov release_task(p); 33639c626aeSOleg Nesterov } 33739c626aeSOleg Nesterov } 33839c626aeSOleg Nesterov 3391da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 3401da177e4SLinus Torvalds { 3411da177e4SLinus Torvalds int copied = 0; 3421da177e4SLinus Torvalds 3431da177e4SLinus Torvalds while (len > 0) { 3441da177e4SLinus Torvalds char buf[128]; 3451da177e4SLinus Torvalds int this_len, retval; 3461da177e4SLinus Torvalds 3471da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 3481da177e4SLinus Torvalds retval = access_process_vm(tsk, src, buf, this_len, 0); 3491da177e4SLinus Torvalds if (!retval) { 3501da177e4SLinus Torvalds if (copied) 3511da177e4SLinus Torvalds break; 3521da177e4SLinus Torvalds return -EIO; 3531da177e4SLinus Torvalds } 3541da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 3551da177e4SLinus Torvalds return -EFAULT; 3561da177e4SLinus Torvalds copied += retval; 3571da177e4SLinus Torvalds src += retval; 3581da177e4SLinus Torvalds dst += retval; 3591da177e4SLinus Torvalds len -= retval; 3601da177e4SLinus Torvalds } 3611da177e4SLinus Torvalds return copied; 3621da177e4SLinus Torvalds } 3631da177e4SLinus Torvalds 3641da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 3651da177e4SLinus Torvalds { 3661da177e4SLinus Torvalds int copied = 0; 3671da177e4SLinus Torvalds 3681da177e4SLinus Torvalds while (len > 0) { 3691da177e4SLinus Torvalds char buf[128]; 3701da177e4SLinus Torvalds int this_len, retval; 3711da177e4SLinus Torvalds 3721da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 3731da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 3741da177e4SLinus Torvalds return -EFAULT; 3751da177e4SLinus Torvalds retval = access_process_vm(tsk, dst, buf, this_len, 1); 3761da177e4SLinus Torvalds if (!retval) { 3771da177e4SLinus Torvalds if (copied) 3781da177e4SLinus Torvalds break; 3791da177e4SLinus Torvalds return -EIO; 3801da177e4SLinus Torvalds } 3811da177e4SLinus Torvalds copied += retval; 3821da177e4SLinus Torvalds src += retval; 3831da177e4SLinus Torvalds dst += retval; 3841da177e4SLinus Torvalds len -= retval; 3851da177e4SLinus Torvalds } 3861da177e4SLinus Torvalds return copied; 3871da177e4SLinus Torvalds } 3881da177e4SLinus Torvalds 3891da177e4SLinus Torvalds static int ptrace_setoptions(struct task_struct *child, long data) 3901da177e4SLinus Torvalds { 3911da177e4SLinus Torvalds child->ptrace &= ~PT_TRACE_MASK; 3921da177e4SLinus Torvalds 3931da177e4SLinus Torvalds if (data & PTRACE_O_TRACESYSGOOD) 3941da177e4SLinus Torvalds child->ptrace |= PT_TRACESYSGOOD; 3951da177e4SLinus Torvalds 3961da177e4SLinus Torvalds if (data & PTRACE_O_TRACEFORK) 3971da177e4SLinus Torvalds child->ptrace |= PT_TRACE_FORK; 3981da177e4SLinus Torvalds 3991da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORK) 4001da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK; 4011da177e4SLinus Torvalds 4021da177e4SLinus Torvalds if (data & PTRACE_O_TRACECLONE) 4031da177e4SLinus Torvalds child->ptrace |= PT_TRACE_CLONE; 4041da177e4SLinus Torvalds 4051da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXEC) 4061da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXEC; 4071da177e4SLinus Torvalds 4081da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORKDONE) 4091da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK_DONE; 4101da177e4SLinus Torvalds 4111da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXIT) 4121da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXIT; 4131da177e4SLinus Torvalds 4141da177e4SLinus Torvalds return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; 4151da177e4SLinus Torvalds } 4161da177e4SLinus Torvalds 417e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 4181da177e4SLinus Torvalds { 4191da177e4SLinus Torvalds int error = -ESRCH; 4201da177e4SLinus Torvalds 4211da177e4SLinus Torvalds read_lock(&tasklist_lock); 4221da177e4SLinus Torvalds if (likely(child->sighand != NULL)) { 4231da177e4SLinus Torvalds error = -EINVAL; 4241da177e4SLinus Torvalds spin_lock_irq(&child->sighand->siglock); 4251da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 426e16b2781SRoland McGrath *info = *child->last_siginfo; 4271da177e4SLinus Torvalds error = 0; 4281da177e4SLinus Torvalds } 4291da177e4SLinus Torvalds spin_unlock_irq(&child->sighand->siglock); 4301da177e4SLinus Torvalds } 4311da177e4SLinus Torvalds read_unlock(&tasklist_lock); 4321da177e4SLinus Torvalds return error; 4331da177e4SLinus Torvalds } 4341da177e4SLinus Torvalds 435e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 4361da177e4SLinus Torvalds { 4371da177e4SLinus Torvalds int error = -ESRCH; 4381da177e4SLinus Torvalds 4391da177e4SLinus Torvalds read_lock(&tasklist_lock); 4401da177e4SLinus Torvalds if (likely(child->sighand != NULL)) { 4411da177e4SLinus Torvalds error = -EINVAL; 4421da177e4SLinus Torvalds spin_lock_irq(&child->sighand->siglock); 4431da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 444e16b2781SRoland McGrath *child->last_siginfo = *info; 4451da177e4SLinus Torvalds error = 0; 4461da177e4SLinus Torvalds } 4471da177e4SLinus Torvalds spin_unlock_irq(&child->sighand->siglock); 4481da177e4SLinus Torvalds } 4491da177e4SLinus Torvalds read_unlock(&tasklist_lock); 4501da177e4SLinus Torvalds return error; 4511da177e4SLinus Torvalds } 4521da177e4SLinus Torvalds 45336df29d7SRoland McGrath 45436df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 45536df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 45636df29d7SRoland McGrath #else 45736df29d7SRoland McGrath #define is_singlestep(request) 0 45836df29d7SRoland McGrath #endif 45936df29d7SRoland McGrath 4605b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 4615b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 4625b88abbfSRoland McGrath #else 4635b88abbfSRoland McGrath #define is_singleblock(request) 0 4645b88abbfSRoland McGrath #endif 4655b88abbfSRoland McGrath 46636df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 46736df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 46836df29d7SRoland McGrath #else 46936df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 47036df29d7SRoland McGrath #endif 47136df29d7SRoland McGrath 47236df29d7SRoland McGrath static int ptrace_resume(struct task_struct *child, long request, long data) 47336df29d7SRoland McGrath { 47436df29d7SRoland McGrath if (!valid_signal(data)) 47536df29d7SRoland McGrath return -EIO; 47636df29d7SRoland McGrath 47736df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 47836df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 47936df29d7SRoland McGrath else 48036df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 48136df29d7SRoland McGrath 48236df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 48336df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 48436df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 48536df29d7SRoland McGrath else 48636df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 48736df29d7SRoland McGrath #endif 48836df29d7SRoland McGrath 4895b88abbfSRoland McGrath if (is_singleblock(request)) { 4905b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 4915b88abbfSRoland McGrath return -EIO; 4925b88abbfSRoland McGrath user_enable_block_step(child); 4935b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 49436df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 49536df29d7SRoland McGrath return -EIO; 49636df29d7SRoland McGrath user_enable_single_step(child); 4973a709703SRoland McGrath } else { 49836df29d7SRoland McGrath user_disable_single_step(child); 4993a709703SRoland McGrath } 50036df29d7SRoland McGrath 50136df29d7SRoland McGrath child->exit_code = data; 50236df29d7SRoland McGrath wake_up_process(child); 50336df29d7SRoland McGrath 50436df29d7SRoland McGrath return 0; 50536df29d7SRoland McGrath } 50636df29d7SRoland McGrath 5071da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 5081da177e4SLinus Torvalds long addr, long data) 5091da177e4SLinus Torvalds { 5101da177e4SLinus Torvalds int ret = -EIO; 511e16b2781SRoland McGrath siginfo_t siginfo; 5121da177e4SLinus Torvalds 5131da177e4SLinus Torvalds switch (request) { 51416c3e389SRoland McGrath case PTRACE_PEEKTEXT: 51516c3e389SRoland McGrath case PTRACE_PEEKDATA: 51616c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 51716c3e389SRoland McGrath case PTRACE_POKETEXT: 51816c3e389SRoland McGrath case PTRACE_POKEDATA: 51916c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 52016c3e389SRoland McGrath 5211da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 5221da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 5231da177e4SLinus Torvalds #endif 5241da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 5251da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 5261da177e4SLinus Torvalds break; 5271da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 5281da177e4SLinus Torvalds ret = put_user(child->ptrace_message, (unsigned long __user *) data); 5291da177e4SLinus Torvalds break; 530e16b2781SRoland McGrath 5311da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 532e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 533e16b2781SRoland McGrath if (!ret) 534e16b2781SRoland McGrath ret = copy_siginfo_to_user((siginfo_t __user *) data, 535e16b2781SRoland McGrath &siginfo); 5361da177e4SLinus Torvalds break; 537e16b2781SRoland McGrath 5381da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 539e16b2781SRoland McGrath if (copy_from_user(&siginfo, (siginfo_t __user *) data, 540e16b2781SRoland McGrath sizeof siginfo)) 541e16b2781SRoland McGrath ret = -EFAULT; 542e16b2781SRoland McGrath else 543e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 5441da177e4SLinus Torvalds break; 545e16b2781SRoland McGrath 5461bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 5471bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 5481bcf5482SAlexey Dobriyan break; 54936df29d7SRoland McGrath 55036df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 55136df29d7SRoland McGrath case PTRACE_SINGLESTEP: 55236df29d7SRoland McGrath #endif 5535b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 5545b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 5555b88abbfSRoland McGrath #endif 55636df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 55736df29d7SRoland McGrath case PTRACE_SYSEMU: 55836df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 55936df29d7SRoland McGrath #endif 56036df29d7SRoland McGrath case PTRACE_SYSCALL: 56136df29d7SRoland McGrath case PTRACE_CONT: 56236df29d7SRoland McGrath return ptrace_resume(child, request, data); 56336df29d7SRoland McGrath 56436df29d7SRoland McGrath case PTRACE_KILL: 56536df29d7SRoland McGrath if (child->exit_state) /* already dead */ 56636df29d7SRoland McGrath return 0; 56736df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 56836df29d7SRoland McGrath 5691da177e4SLinus Torvalds default: 5701da177e4SLinus Torvalds break; 5711da177e4SLinus Torvalds } 5721da177e4SLinus Torvalds 5731da177e4SLinus Torvalds return ret; 5741da177e4SLinus Torvalds } 575481bed45SChristoph Hellwig 5766b9c7ed8SChristoph Hellwig /** 5776b9c7ed8SChristoph Hellwig * ptrace_traceme -- helper for PTRACE_TRACEME 5786b9c7ed8SChristoph Hellwig * 5796b9c7ed8SChristoph Hellwig * Performs checks and sets PT_PTRACED. 5806b9c7ed8SChristoph Hellwig * Should be used by all ptrace implementations for PTRACE_TRACEME. 5816b9c7ed8SChristoph Hellwig */ 5826b9c7ed8SChristoph Hellwig int ptrace_traceme(void) 583481bed45SChristoph Hellwig { 584f5b40e36SLinus Torvalds int ret = -EPERM; 585481bed45SChristoph Hellwig 586481bed45SChristoph Hellwig /* 587481bed45SChristoph Hellwig * Are we already being traced? 588481bed45SChristoph Hellwig */ 589f470021aSRoland McGrath repeat: 590f5b40e36SLinus Torvalds task_lock(current); 591f5b40e36SLinus Torvalds if (!(current->ptrace & PT_PTRACED)) { 592f470021aSRoland McGrath /* 593f470021aSRoland McGrath * See ptrace_attach() comments about the locking here. 594f470021aSRoland McGrath */ 595f470021aSRoland McGrath unsigned long flags; 596f470021aSRoland McGrath if (!write_trylock_irqsave(&tasklist_lock, flags)) { 597f470021aSRoland McGrath task_unlock(current); 598f470021aSRoland McGrath do { 599f470021aSRoland McGrath cpu_relax(); 600f470021aSRoland McGrath } while (!write_can_lock(&tasklist_lock)); 601f470021aSRoland McGrath goto repeat; 602f470021aSRoland McGrath } 603f470021aSRoland McGrath 6045cd9c58fSDavid Howells ret = security_ptrace_traceme(current->parent); 605f470021aSRoland McGrath 606481bed45SChristoph Hellwig /* 607481bed45SChristoph Hellwig * Set the ptrace bit in the process ptrace flags. 608f470021aSRoland McGrath * Then link us on our parent's ptraced list. 609481bed45SChristoph Hellwig */ 610f470021aSRoland McGrath if (!ret) { 611481bed45SChristoph Hellwig current->ptrace |= PT_PTRACED; 612f470021aSRoland McGrath __ptrace_link(current, current->real_parent); 613f470021aSRoland McGrath } 614f470021aSRoland McGrath 615f470021aSRoland McGrath write_unlock_irqrestore(&tasklist_lock, flags); 616f5b40e36SLinus Torvalds } 617f5b40e36SLinus Torvalds task_unlock(current); 618f5b40e36SLinus Torvalds return ret; 619481bed45SChristoph Hellwig } 620481bed45SChristoph Hellwig 6216b9c7ed8SChristoph Hellwig /** 6226b9c7ed8SChristoph Hellwig * ptrace_get_task_struct -- grab a task struct reference for ptrace 6236b9c7ed8SChristoph Hellwig * @pid: process id to grab a task_struct reference of 6246b9c7ed8SChristoph Hellwig * 6256b9c7ed8SChristoph Hellwig * This function is a helper for ptrace implementations. It checks 6266b9c7ed8SChristoph Hellwig * permissions and then grabs a task struct for use of the actual 6276b9c7ed8SChristoph Hellwig * ptrace implementation. 6286b9c7ed8SChristoph Hellwig * 6296b9c7ed8SChristoph Hellwig * Returns the task_struct for @pid or an ERR_PTR() on failure. 6306b9c7ed8SChristoph Hellwig */ 6316b9c7ed8SChristoph Hellwig struct task_struct *ptrace_get_task_struct(pid_t pid) 6326b9c7ed8SChristoph Hellwig { 6336b9c7ed8SChristoph Hellwig struct task_struct *child; 6346b9c7ed8SChristoph Hellwig 635481bed45SChristoph Hellwig read_lock(&tasklist_lock); 636228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 637481bed45SChristoph Hellwig if (child) 638481bed45SChristoph Hellwig get_task_struct(child); 639f400e198SSukadev Bhattiprolu 640481bed45SChristoph Hellwig read_unlock(&tasklist_lock); 641481bed45SChristoph Hellwig if (!child) 6426b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 6436b9c7ed8SChristoph Hellwig return child; 644481bed45SChristoph Hellwig } 645481bed45SChristoph Hellwig 6460ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 6470ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 6480ac15559SChristoph Hellwig #endif 6490ac15559SChristoph Hellwig 6501e7bfb21SHeiko Carstens SYSCALL_DEFINE4(ptrace, long, request, long, pid, long, addr, long, data) 651481bed45SChristoph Hellwig { 652481bed45SChristoph Hellwig struct task_struct *child; 653481bed45SChristoph Hellwig long ret; 654481bed45SChristoph Hellwig 655481bed45SChristoph Hellwig /* 656481bed45SChristoph Hellwig * This lock_kernel fixes a subtle race with suid exec 657481bed45SChristoph Hellwig */ 658481bed45SChristoph Hellwig lock_kernel(); 6596b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 6606b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 6616ea6dd93SHaavard Skinnemoen if (!ret) 6626ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 663481bed45SChristoph Hellwig goto out; 6646b9c7ed8SChristoph Hellwig } 6656b9c7ed8SChristoph Hellwig 6666b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 6676b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 6686b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 6696b9c7ed8SChristoph Hellwig goto out; 6706b9c7ed8SChristoph Hellwig } 671481bed45SChristoph Hellwig 672481bed45SChristoph Hellwig if (request == PTRACE_ATTACH) { 673481bed45SChristoph Hellwig ret = ptrace_attach(child); 6740ac15559SChristoph Hellwig /* 6750ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 6760ac15559SChristoph Hellwig * a ptrace attach. 6770ac15559SChristoph Hellwig */ 6780ac15559SChristoph Hellwig if (!ret) 6790ac15559SChristoph Hellwig arch_ptrace_attach(child); 680005f18dfSChristoph Hellwig goto out_put_task_struct; 681481bed45SChristoph Hellwig } 682481bed45SChristoph Hellwig 683481bed45SChristoph Hellwig ret = ptrace_check_attach(child, request == PTRACE_KILL); 684481bed45SChristoph Hellwig if (ret < 0) 685481bed45SChristoph Hellwig goto out_put_task_struct; 686481bed45SChristoph Hellwig 687481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 688481bed45SChristoph Hellwig 689481bed45SChristoph Hellwig out_put_task_struct: 690481bed45SChristoph Hellwig put_task_struct(child); 691481bed45SChristoph Hellwig out: 692481bed45SChristoph Hellwig unlock_kernel(); 693481bed45SChristoph Hellwig return ret; 694481bed45SChristoph Hellwig } 69576647323SAlexey Dobriyan 69676647323SAlexey Dobriyan int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data) 69776647323SAlexey Dobriyan { 69876647323SAlexey Dobriyan unsigned long tmp; 69976647323SAlexey Dobriyan int copied; 70076647323SAlexey Dobriyan 70176647323SAlexey Dobriyan copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); 70276647323SAlexey Dobriyan if (copied != sizeof(tmp)) 70376647323SAlexey Dobriyan return -EIO; 70476647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 70576647323SAlexey Dobriyan } 706f284ce72SAlexey Dobriyan 707f284ce72SAlexey Dobriyan int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data) 708f284ce72SAlexey Dobriyan { 709f284ce72SAlexey Dobriyan int copied; 710f284ce72SAlexey Dobriyan 711f284ce72SAlexey Dobriyan copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); 712f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 713f284ce72SAlexey Dobriyan } 714032d82d9SRoland McGrath 71596b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 716032d82d9SRoland McGrath #include <linux/compat.h> 717032d82d9SRoland McGrath 718032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 719032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 720032d82d9SRoland McGrath { 721032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 722032d82d9SRoland McGrath compat_ulong_t word; 723e16b2781SRoland McGrath siginfo_t siginfo; 724032d82d9SRoland McGrath int ret; 725032d82d9SRoland McGrath 726032d82d9SRoland McGrath switch (request) { 727032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 728032d82d9SRoland McGrath case PTRACE_PEEKDATA: 729032d82d9SRoland McGrath ret = access_process_vm(child, addr, &word, sizeof(word), 0); 730032d82d9SRoland McGrath if (ret != sizeof(word)) 731032d82d9SRoland McGrath ret = -EIO; 732032d82d9SRoland McGrath else 733032d82d9SRoland McGrath ret = put_user(word, datap); 734032d82d9SRoland McGrath break; 735032d82d9SRoland McGrath 736032d82d9SRoland McGrath case PTRACE_POKETEXT: 737032d82d9SRoland McGrath case PTRACE_POKEDATA: 738032d82d9SRoland McGrath ret = access_process_vm(child, addr, &data, sizeof(data), 1); 739032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 740032d82d9SRoland McGrath break; 741032d82d9SRoland McGrath 742032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 743032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 744032d82d9SRoland McGrath break; 745032d82d9SRoland McGrath 746e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 747e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 748e16b2781SRoland McGrath if (!ret) 749e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 750e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 751e16b2781SRoland McGrath &siginfo); 752e16b2781SRoland McGrath break; 753e16b2781SRoland McGrath 754e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 755e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 756e16b2781SRoland McGrath if (copy_siginfo_from_user32( 757e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 758e16b2781SRoland McGrath ret = -EFAULT; 759e16b2781SRoland McGrath else 760e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 761e16b2781SRoland McGrath break; 762e16b2781SRoland McGrath 763032d82d9SRoland McGrath default: 764032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 765032d82d9SRoland McGrath } 766032d82d9SRoland McGrath 767032d82d9SRoland McGrath return ret; 768032d82d9SRoland McGrath } 769c269f196SRoland McGrath 770c269f196SRoland McGrath asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, 771c269f196SRoland McGrath compat_long_t addr, compat_long_t data) 772c269f196SRoland McGrath { 773c269f196SRoland McGrath struct task_struct *child; 774c269f196SRoland McGrath long ret; 775c269f196SRoland McGrath 776c269f196SRoland McGrath /* 777c269f196SRoland McGrath * This lock_kernel fixes a subtle race with suid exec 778c269f196SRoland McGrath */ 779c269f196SRoland McGrath lock_kernel(); 780c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 781c269f196SRoland McGrath ret = ptrace_traceme(); 782c269f196SRoland McGrath goto out; 783c269f196SRoland McGrath } 784c269f196SRoland McGrath 785c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 786c269f196SRoland McGrath if (IS_ERR(child)) { 787c269f196SRoland McGrath ret = PTR_ERR(child); 788c269f196SRoland McGrath goto out; 789c269f196SRoland McGrath } 790c269f196SRoland McGrath 791c269f196SRoland McGrath if (request == PTRACE_ATTACH) { 792c269f196SRoland McGrath ret = ptrace_attach(child); 793c269f196SRoland McGrath /* 794c269f196SRoland McGrath * Some architectures need to do book-keeping after 795c269f196SRoland McGrath * a ptrace attach. 796c269f196SRoland McGrath */ 797c269f196SRoland McGrath if (!ret) 798c269f196SRoland McGrath arch_ptrace_attach(child); 799c269f196SRoland McGrath goto out_put_task_struct; 800c269f196SRoland McGrath } 801c269f196SRoland McGrath 802c269f196SRoland McGrath ret = ptrace_check_attach(child, request == PTRACE_KILL); 803c269f196SRoland McGrath if (!ret) 804c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 805c269f196SRoland McGrath 806c269f196SRoland McGrath out_put_task_struct: 807c269f196SRoland McGrath put_task_struct(child); 808c269f196SRoland McGrath out: 809c269f196SRoland McGrath unlock_kernel(); 810c269f196SRoland McGrath return ret; 811c269f196SRoland McGrath } 81296b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 813