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> 252225a122SSuresh Siddha #include <linux/regset.h> 261da177e4SLinus Torvalds 27bf53de90SMarkus Metzger 28bf53de90SMarkus Metzger /* 291da177e4SLinus Torvalds * ptrace a task: make the debugger its new parent and 301da177e4SLinus Torvalds * move it to the ptrace list. 311da177e4SLinus Torvalds * 321da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 331da177e4SLinus Torvalds */ 3436c8b586SIngo Molnar void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) 351da177e4SLinus Torvalds { 36f470021aSRoland McGrath BUG_ON(!list_empty(&child->ptrace_entry)); 37f470021aSRoland McGrath list_add(&child->ptrace_entry, &new_parent->ptraced); 381da177e4SLinus Torvalds child->parent = new_parent; 391da177e4SLinus Torvalds } 401da177e4SLinus Torvalds 411da177e4SLinus Torvalds /* 421da177e4SLinus Torvalds * Turn a tracing stop into a normal stop now, since with no tracer there 431da177e4SLinus Torvalds * would be no way to wake it up with SIGCONT or SIGKILL. If there was a 441da177e4SLinus Torvalds * signal sent that would resume the child, but didn't because it was in 451da177e4SLinus Torvalds * TASK_TRACED, resume it now. 461da177e4SLinus Torvalds * Requires that irqs be disabled. 471da177e4SLinus Torvalds */ 48b747c8c1SAdrian Bunk static void ptrace_untrace(struct task_struct *child) 491da177e4SLinus Torvalds { 501da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 516618a3e2SMatthew Wilcox if (task_is_traced(child)) { 521ee11844SOleg Nesterov /* 531ee11844SOleg Nesterov * If the group stop is completed or in progress, 541ee11844SOleg Nesterov * this thread was already counted as stopped. 551ee11844SOleg Nesterov */ 561ee11844SOleg Nesterov if (child->signal->flags & SIGNAL_STOP_STOPPED || 571ee11844SOleg Nesterov child->signal->group_stop_count) 58d9ae90acSOleg Nesterov __set_task_state(child, TASK_STOPPED); 591ee11844SOleg Nesterov else 601da177e4SLinus Torvalds signal_wake_up(child, 1); 611da177e4SLinus Torvalds } 621da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 631da177e4SLinus Torvalds } 641da177e4SLinus Torvalds 651da177e4SLinus Torvalds /* 661da177e4SLinus Torvalds * unptrace a task: move it back to its original parent and 671da177e4SLinus Torvalds * remove it from the ptrace list. 681da177e4SLinus Torvalds * 691da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 701da177e4SLinus Torvalds */ 7136c8b586SIngo Molnar void __ptrace_unlink(struct task_struct *child) 721da177e4SLinus Torvalds { 735ecfbae0SOleg Nesterov BUG_ON(!child->ptrace); 745ecfbae0SOleg Nesterov 751da177e4SLinus Torvalds child->ptrace = 0; 761da177e4SLinus Torvalds child->parent = child->real_parent; 77f470021aSRoland McGrath list_del_init(&child->ptrace_entry); 781da177e4SLinus Torvalds 79bf53de90SMarkus Metzger arch_ptrace_untrace(child); 806618a3e2SMatthew Wilcox if (task_is_traced(child)) 811da177e4SLinus Torvalds ptrace_untrace(child); 821da177e4SLinus Torvalds } 831da177e4SLinus Torvalds 841da177e4SLinus Torvalds /* 851da177e4SLinus Torvalds * Check that we have indeed attached to the thing.. 861da177e4SLinus Torvalds */ 871da177e4SLinus Torvalds int ptrace_check_attach(struct task_struct *child, int kill) 881da177e4SLinus Torvalds { 891da177e4SLinus Torvalds int ret = -ESRCH; 901da177e4SLinus Torvalds 911da177e4SLinus Torvalds /* 921da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 931da177e4SLinus Torvalds * possible race where someone else was tracing our child and 941da177e4SLinus Torvalds * detached between these two checks. After this locked check, 951da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 961da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 971da177e4SLinus Torvalds */ 981da177e4SLinus Torvalds read_lock(&tasklist_lock); 99c0c0b649SOleg Nesterov if ((child->ptrace & PT_PTRACED) && child->parent == current) { 1001da177e4SLinus Torvalds ret = 0; 101c0c0b649SOleg Nesterov /* 102c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 103c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 104c0c0b649SOleg Nesterov */ 1051da177e4SLinus Torvalds spin_lock_irq(&child->sighand->siglock); 106d9ae90acSOleg Nesterov if (task_is_stopped(child)) 1071da177e4SLinus Torvalds child->state = TASK_TRACED; 108d9ae90acSOleg Nesterov else if (!task_is_traced(child) && !kill) 1091da177e4SLinus Torvalds ret = -ESRCH; 1101da177e4SLinus Torvalds spin_unlock_irq(&child->sighand->siglock); 1111da177e4SLinus Torvalds } 1121da177e4SLinus Torvalds read_unlock(&tasklist_lock); 1131da177e4SLinus Torvalds 114d9ae90acSOleg Nesterov if (!ret && !kill) 11585ba2d86SRoland McGrath ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; 1161da177e4SLinus Torvalds 1171da177e4SLinus Torvalds /* All systems go.. */ 1181da177e4SLinus Torvalds return ret; 1191da177e4SLinus Torvalds } 1201da177e4SLinus Torvalds 121006ebb40SStephen Smalley int __ptrace_may_access(struct task_struct *task, unsigned int mode) 122ab8d11beSMiklos Szeredi { 123c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 124b6dff3ecSDavid Howells 125df26c40eSEric W. Biederman /* May we inspect the given task? 126df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 127df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 128df26c40eSEric W. Biederman * 129df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 130df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 131df26c40eSEric W. Biederman * or halting the specified task is impossible. 132df26c40eSEric W. Biederman */ 133df26c40eSEric W. Biederman int dumpable = 0; 134df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 135df26c40eSEric W. Biederman if (task == current) 136df26c40eSEric W. Biederman return 0; 137c69e8d9cSDavid Howells rcu_read_lock(); 138c69e8d9cSDavid Howells tcred = __task_cred(task); 139c69e8d9cSDavid Howells if ((cred->uid != tcred->euid || 140c69e8d9cSDavid Howells cred->uid != tcred->suid || 141c69e8d9cSDavid Howells cred->uid != tcred->uid || 142c69e8d9cSDavid Howells cred->gid != tcred->egid || 143c69e8d9cSDavid Howells cred->gid != tcred->sgid || 144c69e8d9cSDavid Howells cred->gid != tcred->gid) && 145c69e8d9cSDavid Howells !capable(CAP_SYS_PTRACE)) { 146c69e8d9cSDavid Howells rcu_read_unlock(); 147ab8d11beSMiklos Szeredi return -EPERM; 148c69e8d9cSDavid Howells } 149c69e8d9cSDavid Howells rcu_read_unlock(); 150ab8d11beSMiklos Szeredi smp_rmb(); 151df26c40eSEric W. Biederman if (task->mm) 1526c5d5238SKawai, Hidehiro dumpable = get_dumpable(task->mm); 153df26c40eSEric W. Biederman if (!dumpable && !capable(CAP_SYS_PTRACE)) 154ab8d11beSMiklos Szeredi return -EPERM; 155ab8d11beSMiklos Szeredi 1569e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 157ab8d11beSMiklos Szeredi } 158ab8d11beSMiklos Szeredi 159006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 160ab8d11beSMiklos Szeredi { 161ab8d11beSMiklos Szeredi int err; 162ab8d11beSMiklos Szeredi task_lock(task); 163006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 164ab8d11beSMiklos Szeredi task_unlock(task); 1653a709703SRoland McGrath return !err; 166ab8d11beSMiklos Szeredi } 167ab8d11beSMiklos Szeredi 1681da177e4SLinus Torvalds int ptrace_attach(struct task_struct *task) 1691da177e4SLinus Torvalds { 1701da177e4SLinus Torvalds int retval; 171f5b40e36SLinus Torvalds 172a5cb013dSAl Viro audit_ptrace(task); 173a5cb013dSAl Viro 1741da177e4SLinus Torvalds retval = -EPERM; 175b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 176b79b7ba9SOleg Nesterov goto out; 177bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 178f5b40e36SLinus Torvalds goto out; 179f5b40e36SLinus Torvalds 180f2f0b00aSOleg Nesterov /* 181f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 1825e751e99SDavid Howells * interference; SUID, SGID and LSM creds get determined differently 1835e751e99SDavid Howells * under ptrace. 184d84f4f99SDavid Howells */ 185793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 186793285fcSOleg Nesterov if (mutex_lock_interruptible(&task->cred_guard_mutex)) 187d84f4f99SDavid Howells goto out; 1884b105cbbSOleg Nesterov 189f5b40e36SLinus Torvalds task_lock(task); 190006ebb40SStephen Smalley retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); 1914b105cbbSOleg Nesterov task_unlock(task); 1921da177e4SLinus Torvalds if (retval) 1934b105cbbSOleg Nesterov goto unlock_creds; 1941da177e4SLinus Torvalds 1954b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 196b79b7ba9SOleg Nesterov retval = -EPERM; 197b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 1984b105cbbSOleg Nesterov goto unlock_tasklist; 199f2f0b00aSOleg Nesterov if (task->ptrace) 2004b105cbbSOleg Nesterov goto unlock_tasklist; 201b79b7ba9SOleg Nesterov 202f2f0b00aSOleg Nesterov task->ptrace = PT_PTRACED; 2031da177e4SLinus Torvalds if (capable(CAP_SYS_PTRACE)) 2041da177e4SLinus Torvalds task->ptrace |= PT_PTRACE_CAP; 2051da177e4SLinus Torvalds 2061da177e4SLinus Torvalds __ptrace_link(task, current); 20733e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 208b79b7ba9SOleg Nesterov 209b79b7ba9SOleg Nesterov retval = 0; 2104b105cbbSOleg Nesterov unlock_tasklist: 2114b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 2124b105cbbSOleg Nesterov unlock_creds: 2135e751e99SDavid Howells mutex_unlock(&task->cred_guard_mutex); 214f5b40e36SLinus Torvalds out: 2151da177e4SLinus Torvalds return retval; 2161da177e4SLinus Torvalds } 2171da177e4SLinus Torvalds 218f2f0b00aSOleg Nesterov /** 219f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 220f2f0b00aSOleg Nesterov * 221f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 222f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 223f2f0b00aSOleg Nesterov */ 224f2f0b00aSOleg Nesterov int ptrace_traceme(void) 225f2f0b00aSOleg Nesterov { 226f2f0b00aSOleg Nesterov int ret = -EPERM; 227f2f0b00aSOleg Nesterov 2284b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 2294b105cbbSOleg Nesterov /* Are we already being traced? */ 230f2f0b00aSOleg Nesterov if (!current->ptrace) { 231f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 232f2f0b00aSOleg Nesterov /* 233f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 234f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 235f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 236f2f0b00aSOleg Nesterov */ 237f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 238f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 239f2f0b00aSOleg Nesterov __ptrace_link(current, current->real_parent); 240f2f0b00aSOleg Nesterov } 241f2f0b00aSOleg Nesterov } 2424b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 2434b105cbbSOleg Nesterov 244f2f0b00aSOleg Nesterov return ret; 245f2f0b00aSOleg Nesterov } 246f2f0b00aSOleg Nesterov 24739c626aeSOleg Nesterov /* 24839c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 24939c626aeSOleg Nesterov */ 25039c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 25139c626aeSOleg Nesterov { 25239c626aeSOleg Nesterov int ret; 25339c626aeSOleg Nesterov spin_lock(&sigh->siglock); 25439c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 25539c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 25639c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 25739c626aeSOleg Nesterov return ret; 25839c626aeSOleg Nesterov } 25939c626aeSOleg Nesterov 26039c626aeSOleg Nesterov /* 26139c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 26239c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 26339c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 26439c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 26539c626aeSOleg Nesterov * 26639c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 26739c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 26839c626aeSOleg Nesterov * If it should reap itself, return true. 26939c626aeSOleg Nesterov * 270a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 271a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 272a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 273a7f0765eSOleg Nesterov * do_wait(). 27439c626aeSOleg Nesterov */ 27539c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 27639c626aeSOleg Nesterov { 27739c626aeSOleg Nesterov __ptrace_unlink(p); 27839c626aeSOleg Nesterov 27939c626aeSOleg Nesterov if (p->exit_state == EXIT_ZOMBIE) { 28039c626aeSOleg Nesterov if (!task_detached(p) && thread_group_empty(p)) { 28139c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 28239c626aeSOleg Nesterov do_notify_parent(p, p->exit_signal); 283a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 284a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 28539c626aeSOleg Nesterov p->exit_signal = -1; 28639c626aeSOleg Nesterov } 287a7f0765eSOleg Nesterov } 28839c626aeSOleg Nesterov if (task_detached(p)) { 28939c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 29039c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 29139c626aeSOleg Nesterov return true; 29239c626aeSOleg Nesterov } 29339c626aeSOleg Nesterov } 29439c626aeSOleg Nesterov 29539c626aeSOleg Nesterov return false; 29639c626aeSOleg Nesterov } 29739c626aeSOleg Nesterov 2981da177e4SLinus Torvalds int ptrace_detach(struct task_struct *child, unsigned int data) 2991da177e4SLinus Torvalds { 30039c626aeSOleg Nesterov bool dead = false; 3014576145cSOleg Nesterov 3027ed20e1aSJesper Juhl if (!valid_signal(data)) 3031da177e4SLinus Torvalds return -EIO; 3041da177e4SLinus Torvalds 3051da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 3061da177e4SLinus Torvalds ptrace_disable(child); 3077d941432SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 3081da177e4SLinus Torvalds 30995c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 31039c626aeSOleg Nesterov /* 31139c626aeSOleg Nesterov * This child can be already killed. Make sure de_thread() or 31239c626aeSOleg Nesterov * our sub-thread doing do_wait() didn't do release_task() yet. 31339c626aeSOleg Nesterov */ 31495c3eb76SOleg Nesterov if (child->ptrace) { 31595c3eb76SOleg Nesterov child->exit_code = data; 3164576145cSOleg Nesterov dead = __ptrace_detach(current, child); 317edaba2c5SOleg Nesterov if (!child->exit_state) 318edaba2c5SOleg Nesterov wake_up_process(child); 31995c3eb76SOleg Nesterov } 3201da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 3211da177e4SLinus Torvalds 3224576145cSOleg Nesterov if (unlikely(dead)) 3234576145cSOleg Nesterov release_task(child); 3244576145cSOleg Nesterov 3251da177e4SLinus Torvalds return 0; 3261da177e4SLinus Torvalds } 3271da177e4SLinus Torvalds 32839c626aeSOleg Nesterov /* 32939c626aeSOleg Nesterov * Detach all tasks we were using ptrace on. 33039c626aeSOleg Nesterov */ 33139c626aeSOleg Nesterov void exit_ptrace(struct task_struct *tracer) 33239c626aeSOleg Nesterov { 33339c626aeSOleg Nesterov struct task_struct *p, *n; 33439c626aeSOleg Nesterov LIST_HEAD(ptrace_dead); 33539c626aeSOleg Nesterov 33639c626aeSOleg Nesterov write_lock_irq(&tasklist_lock); 33739c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 33839c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 33939c626aeSOleg Nesterov list_add(&p->ptrace_entry, &ptrace_dead); 34039c626aeSOleg Nesterov } 34139c626aeSOleg Nesterov write_unlock_irq(&tasklist_lock); 34239c626aeSOleg Nesterov 34339c626aeSOleg Nesterov BUG_ON(!list_empty(&tracer->ptraced)); 34439c626aeSOleg Nesterov 34539c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { 34639c626aeSOleg Nesterov list_del_init(&p->ptrace_entry); 34739c626aeSOleg Nesterov release_task(p); 34839c626aeSOleg Nesterov } 34939c626aeSOleg Nesterov } 35039c626aeSOleg Nesterov 3511da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 3521da177e4SLinus Torvalds { 3531da177e4SLinus Torvalds int copied = 0; 3541da177e4SLinus Torvalds 3551da177e4SLinus Torvalds while (len > 0) { 3561da177e4SLinus Torvalds char buf[128]; 3571da177e4SLinus Torvalds int this_len, retval; 3581da177e4SLinus Torvalds 3591da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 3601da177e4SLinus Torvalds retval = access_process_vm(tsk, src, buf, this_len, 0); 3611da177e4SLinus Torvalds if (!retval) { 3621da177e4SLinus Torvalds if (copied) 3631da177e4SLinus Torvalds break; 3641da177e4SLinus Torvalds return -EIO; 3651da177e4SLinus Torvalds } 3661da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 3671da177e4SLinus Torvalds return -EFAULT; 3681da177e4SLinus Torvalds copied += retval; 3691da177e4SLinus Torvalds src += retval; 3701da177e4SLinus Torvalds dst += retval; 3711da177e4SLinus Torvalds len -= retval; 3721da177e4SLinus Torvalds } 3731da177e4SLinus Torvalds return copied; 3741da177e4SLinus Torvalds } 3751da177e4SLinus Torvalds 3761da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 3771da177e4SLinus Torvalds { 3781da177e4SLinus Torvalds int copied = 0; 3791da177e4SLinus Torvalds 3801da177e4SLinus Torvalds while (len > 0) { 3811da177e4SLinus Torvalds char buf[128]; 3821da177e4SLinus Torvalds int this_len, retval; 3831da177e4SLinus Torvalds 3841da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 3851da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 3861da177e4SLinus Torvalds return -EFAULT; 3871da177e4SLinus Torvalds retval = access_process_vm(tsk, dst, buf, this_len, 1); 3881da177e4SLinus Torvalds if (!retval) { 3891da177e4SLinus Torvalds if (copied) 3901da177e4SLinus Torvalds break; 3911da177e4SLinus Torvalds return -EIO; 3921da177e4SLinus Torvalds } 3931da177e4SLinus Torvalds copied += retval; 3941da177e4SLinus Torvalds src += retval; 3951da177e4SLinus Torvalds dst += retval; 3961da177e4SLinus Torvalds len -= retval; 3971da177e4SLinus Torvalds } 3981da177e4SLinus Torvalds return copied; 3991da177e4SLinus Torvalds } 4001da177e4SLinus Torvalds 4011da177e4SLinus Torvalds static int ptrace_setoptions(struct task_struct *child, long data) 4021da177e4SLinus Torvalds { 4031da177e4SLinus Torvalds child->ptrace &= ~PT_TRACE_MASK; 4041da177e4SLinus Torvalds 4051da177e4SLinus Torvalds if (data & PTRACE_O_TRACESYSGOOD) 4061da177e4SLinus Torvalds child->ptrace |= PT_TRACESYSGOOD; 4071da177e4SLinus Torvalds 4081da177e4SLinus Torvalds if (data & PTRACE_O_TRACEFORK) 4091da177e4SLinus Torvalds child->ptrace |= PT_TRACE_FORK; 4101da177e4SLinus Torvalds 4111da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORK) 4121da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK; 4131da177e4SLinus Torvalds 4141da177e4SLinus Torvalds if (data & PTRACE_O_TRACECLONE) 4151da177e4SLinus Torvalds child->ptrace |= PT_TRACE_CLONE; 4161da177e4SLinus Torvalds 4171da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXEC) 4181da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXEC; 4191da177e4SLinus Torvalds 4201da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORKDONE) 4211da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK_DONE; 4221da177e4SLinus Torvalds 4231da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXIT) 4241da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXIT; 4251da177e4SLinus Torvalds 4261da177e4SLinus Torvalds return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; 4271da177e4SLinus Torvalds } 4281da177e4SLinus Torvalds 429e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 4301da177e4SLinus Torvalds { 431e4961254SOleg Nesterov unsigned long flags; 4321da177e4SLinus Torvalds int error = -ESRCH; 4331da177e4SLinus Torvalds 434e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 4351da177e4SLinus Torvalds error = -EINVAL; 4361da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 437e16b2781SRoland McGrath *info = *child->last_siginfo; 4381da177e4SLinus Torvalds error = 0; 4391da177e4SLinus Torvalds } 440e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 4411da177e4SLinus Torvalds } 4421da177e4SLinus Torvalds return error; 4431da177e4SLinus Torvalds } 4441da177e4SLinus Torvalds 445e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 4461da177e4SLinus Torvalds { 447e4961254SOleg Nesterov unsigned long flags; 4481da177e4SLinus Torvalds int error = -ESRCH; 4491da177e4SLinus Torvalds 450e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 4511da177e4SLinus Torvalds error = -EINVAL; 4521da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 453e16b2781SRoland McGrath *child->last_siginfo = *info; 4541da177e4SLinus Torvalds error = 0; 4551da177e4SLinus Torvalds } 456e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 4571da177e4SLinus Torvalds } 4581da177e4SLinus Torvalds return error; 4591da177e4SLinus Torvalds } 4601da177e4SLinus Torvalds 46136df29d7SRoland McGrath 46236df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 46336df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 46436df29d7SRoland McGrath #else 46536df29d7SRoland McGrath #define is_singlestep(request) 0 46636df29d7SRoland McGrath #endif 46736df29d7SRoland McGrath 4685b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 4695b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 4705b88abbfSRoland McGrath #else 4715b88abbfSRoland McGrath #define is_singleblock(request) 0 4725b88abbfSRoland McGrath #endif 4735b88abbfSRoland McGrath 47436df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 47536df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 47636df29d7SRoland McGrath #else 47736df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 47836df29d7SRoland McGrath #endif 47936df29d7SRoland McGrath 48036df29d7SRoland McGrath static int ptrace_resume(struct task_struct *child, long request, long data) 48136df29d7SRoland McGrath { 48236df29d7SRoland McGrath if (!valid_signal(data)) 48336df29d7SRoland McGrath return -EIO; 48436df29d7SRoland McGrath 48536df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 48636df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 48736df29d7SRoland McGrath else 48836df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 48936df29d7SRoland McGrath 49036df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 49136df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 49236df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 49336df29d7SRoland McGrath else 49436df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 49536df29d7SRoland McGrath #endif 49636df29d7SRoland McGrath 4975b88abbfSRoland McGrath if (is_singleblock(request)) { 4985b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 4995b88abbfSRoland McGrath return -EIO; 5005b88abbfSRoland McGrath user_enable_block_step(child); 5015b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 50236df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 50336df29d7SRoland McGrath return -EIO; 50436df29d7SRoland McGrath user_enable_single_step(child); 5053a709703SRoland McGrath } else { 50636df29d7SRoland McGrath user_disable_single_step(child); 5073a709703SRoland McGrath } 50836df29d7SRoland McGrath 50936df29d7SRoland McGrath child->exit_code = data; 51036df29d7SRoland McGrath wake_up_process(child); 51136df29d7SRoland McGrath 51236df29d7SRoland McGrath return 0; 51336df29d7SRoland McGrath } 51436df29d7SRoland McGrath 5152225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 5162225a122SSuresh Siddha 5172225a122SSuresh Siddha static const struct user_regset * 5182225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 5192225a122SSuresh Siddha { 5202225a122SSuresh Siddha const struct user_regset *regset; 5212225a122SSuresh Siddha int n; 5222225a122SSuresh Siddha 5232225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 5242225a122SSuresh Siddha regset = view->regsets + n; 5252225a122SSuresh Siddha if (regset->core_note_type == type) 5262225a122SSuresh Siddha return regset; 5272225a122SSuresh Siddha } 5282225a122SSuresh Siddha 5292225a122SSuresh Siddha return NULL; 5302225a122SSuresh Siddha } 5312225a122SSuresh Siddha 5322225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 5332225a122SSuresh Siddha struct iovec *kiov) 5342225a122SSuresh Siddha { 5352225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 5362225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 5372225a122SSuresh Siddha int regset_no; 5382225a122SSuresh Siddha 5392225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 5402225a122SSuresh Siddha return -EIO; 5412225a122SSuresh Siddha 5422225a122SSuresh Siddha regset_no = regset - view->regsets; 5432225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 5442225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 5452225a122SSuresh Siddha 5462225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 5472225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 5482225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 5492225a122SSuresh Siddha else 5502225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 5512225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 5522225a122SSuresh Siddha } 5532225a122SSuresh Siddha 5542225a122SSuresh Siddha #endif 5552225a122SSuresh Siddha 5561da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 5571da177e4SLinus Torvalds long addr, long data) 5581da177e4SLinus Torvalds { 5591da177e4SLinus Torvalds int ret = -EIO; 560e16b2781SRoland McGrath siginfo_t siginfo; 5611da177e4SLinus Torvalds 5621da177e4SLinus Torvalds switch (request) { 56316c3e389SRoland McGrath case PTRACE_PEEKTEXT: 56416c3e389SRoland McGrath case PTRACE_PEEKDATA: 56516c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 56616c3e389SRoland McGrath case PTRACE_POKETEXT: 56716c3e389SRoland McGrath case PTRACE_POKEDATA: 56816c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 56916c3e389SRoland McGrath 5701da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 5711da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 5721da177e4SLinus Torvalds #endif 5731da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 5741da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 5751da177e4SLinus Torvalds break; 5761da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 5771da177e4SLinus Torvalds ret = put_user(child->ptrace_message, (unsigned long __user *) data); 5781da177e4SLinus Torvalds break; 579e16b2781SRoland McGrath 5801da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 581e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 582e16b2781SRoland McGrath if (!ret) 583e16b2781SRoland McGrath ret = copy_siginfo_to_user((siginfo_t __user *) data, 584e16b2781SRoland McGrath &siginfo); 5851da177e4SLinus Torvalds break; 586e16b2781SRoland McGrath 5871da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 588e16b2781SRoland McGrath if (copy_from_user(&siginfo, (siginfo_t __user *) data, 589e16b2781SRoland McGrath sizeof siginfo)) 590e16b2781SRoland McGrath ret = -EFAULT; 591e16b2781SRoland McGrath else 592e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 5931da177e4SLinus Torvalds break; 594e16b2781SRoland McGrath 5951bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 5961bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 5971bcf5482SAlexey Dobriyan break; 59836df29d7SRoland McGrath 59936df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 60036df29d7SRoland McGrath case PTRACE_SINGLESTEP: 60136df29d7SRoland McGrath #endif 6025b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 6035b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 6045b88abbfSRoland McGrath #endif 60536df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 60636df29d7SRoland McGrath case PTRACE_SYSEMU: 60736df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 60836df29d7SRoland McGrath #endif 60936df29d7SRoland McGrath case PTRACE_SYSCALL: 61036df29d7SRoland McGrath case PTRACE_CONT: 61136df29d7SRoland McGrath return ptrace_resume(child, request, data); 61236df29d7SRoland McGrath 61336df29d7SRoland McGrath case PTRACE_KILL: 61436df29d7SRoland McGrath if (child->exit_state) /* already dead */ 61536df29d7SRoland McGrath return 0; 61636df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 61736df29d7SRoland McGrath 6182225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 6192225a122SSuresh Siddha case PTRACE_GETREGSET: 6202225a122SSuresh Siddha case PTRACE_SETREGSET: 6212225a122SSuresh Siddha { 6222225a122SSuresh Siddha struct iovec kiov; 6232225a122SSuresh Siddha struct iovec __user *uiov = (struct iovec __user *) data; 6242225a122SSuresh Siddha 6252225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 6262225a122SSuresh Siddha return -EFAULT; 6272225a122SSuresh Siddha 6282225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 6292225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 6302225a122SSuresh Siddha return -EFAULT; 6312225a122SSuresh Siddha 6322225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 6332225a122SSuresh Siddha if (!ret) 6342225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 6352225a122SSuresh Siddha break; 6362225a122SSuresh Siddha } 6372225a122SSuresh Siddha #endif 6381da177e4SLinus Torvalds default: 6391da177e4SLinus Torvalds break; 6401da177e4SLinus Torvalds } 6411da177e4SLinus Torvalds 6421da177e4SLinus Torvalds return ret; 6431da177e4SLinus Torvalds } 644481bed45SChristoph Hellwig 6458053bdd5SOleg Nesterov static struct task_struct *ptrace_get_task_struct(pid_t pid) 6466b9c7ed8SChristoph Hellwig { 6476b9c7ed8SChristoph Hellwig struct task_struct *child; 6486b9c7ed8SChristoph Hellwig 6498053bdd5SOleg Nesterov rcu_read_lock(); 650228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 651481bed45SChristoph Hellwig if (child) 652481bed45SChristoph Hellwig get_task_struct(child); 6538053bdd5SOleg Nesterov rcu_read_unlock(); 654f400e198SSukadev Bhattiprolu 655481bed45SChristoph Hellwig if (!child) 6566b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 6576b9c7ed8SChristoph Hellwig return child; 658481bed45SChristoph Hellwig } 659481bed45SChristoph Hellwig 6600ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 6610ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 6620ac15559SChristoph Hellwig #endif 6630ac15559SChristoph Hellwig 6641e7bfb21SHeiko Carstens SYSCALL_DEFINE4(ptrace, long, request, long, pid, long, addr, long, data) 665481bed45SChristoph Hellwig { 666481bed45SChristoph Hellwig struct task_struct *child; 667481bed45SChristoph Hellwig long ret; 668481bed45SChristoph Hellwig 669481bed45SChristoph Hellwig /* 670481bed45SChristoph Hellwig * This lock_kernel fixes a subtle race with suid exec 671481bed45SChristoph Hellwig */ 672481bed45SChristoph Hellwig lock_kernel(); 6736b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 6746b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 6756ea6dd93SHaavard Skinnemoen if (!ret) 6766ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 677481bed45SChristoph Hellwig goto out; 6786b9c7ed8SChristoph Hellwig } 6796b9c7ed8SChristoph Hellwig 6806b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 6816b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 6826b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 6836b9c7ed8SChristoph Hellwig goto out; 6846b9c7ed8SChristoph Hellwig } 685481bed45SChristoph Hellwig 686481bed45SChristoph Hellwig if (request == PTRACE_ATTACH) { 687481bed45SChristoph Hellwig ret = ptrace_attach(child); 6880ac15559SChristoph Hellwig /* 6890ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 6900ac15559SChristoph Hellwig * a ptrace attach. 6910ac15559SChristoph Hellwig */ 6920ac15559SChristoph Hellwig if (!ret) 6930ac15559SChristoph Hellwig arch_ptrace_attach(child); 694005f18dfSChristoph Hellwig goto out_put_task_struct; 695481bed45SChristoph Hellwig } 696481bed45SChristoph Hellwig 697481bed45SChristoph Hellwig ret = ptrace_check_attach(child, request == PTRACE_KILL); 698481bed45SChristoph Hellwig if (ret < 0) 699481bed45SChristoph Hellwig goto out_put_task_struct; 700481bed45SChristoph Hellwig 701481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 702481bed45SChristoph Hellwig 703481bed45SChristoph Hellwig out_put_task_struct: 704481bed45SChristoph Hellwig put_task_struct(child); 705481bed45SChristoph Hellwig out: 706481bed45SChristoph Hellwig unlock_kernel(); 707481bed45SChristoph Hellwig return ret; 708481bed45SChristoph Hellwig } 70976647323SAlexey Dobriyan 71076647323SAlexey Dobriyan int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data) 71176647323SAlexey Dobriyan { 71276647323SAlexey Dobriyan unsigned long tmp; 71376647323SAlexey Dobriyan int copied; 71476647323SAlexey Dobriyan 71576647323SAlexey Dobriyan copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); 71676647323SAlexey Dobriyan if (copied != sizeof(tmp)) 71776647323SAlexey Dobriyan return -EIO; 71876647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 71976647323SAlexey Dobriyan } 720f284ce72SAlexey Dobriyan 721f284ce72SAlexey Dobriyan int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data) 722f284ce72SAlexey Dobriyan { 723f284ce72SAlexey Dobriyan int copied; 724f284ce72SAlexey Dobriyan 725f284ce72SAlexey Dobriyan copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); 726f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 727f284ce72SAlexey Dobriyan } 728032d82d9SRoland McGrath 72996b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 730032d82d9SRoland McGrath #include <linux/compat.h> 731032d82d9SRoland McGrath 732032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 733032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 734032d82d9SRoland McGrath { 735032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 736032d82d9SRoland McGrath compat_ulong_t word; 737e16b2781SRoland McGrath siginfo_t siginfo; 738032d82d9SRoland McGrath int ret; 739032d82d9SRoland McGrath 740032d82d9SRoland McGrath switch (request) { 741032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 742032d82d9SRoland McGrath case PTRACE_PEEKDATA: 743032d82d9SRoland McGrath ret = access_process_vm(child, addr, &word, sizeof(word), 0); 744032d82d9SRoland McGrath if (ret != sizeof(word)) 745032d82d9SRoland McGrath ret = -EIO; 746032d82d9SRoland McGrath else 747032d82d9SRoland McGrath ret = put_user(word, datap); 748032d82d9SRoland McGrath break; 749032d82d9SRoland McGrath 750032d82d9SRoland McGrath case PTRACE_POKETEXT: 751032d82d9SRoland McGrath case PTRACE_POKEDATA: 752032d82d9SRoland McGrath ret = access_process_vm(child, addr, &data, sizeof(data), 1); 753032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 754032d82d9SRoland McGrath break; 755032d82d9SRoland McGrath 756032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 757032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 758032d82d9SRoland McGrath break; 759032d82d9SRoland McGrath 760e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 761e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 762e16b2781SRoland McGrath if (!ret) 763e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 764e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 765e16b2781SRoland McGrath &siginfo); 766e16b2781SRoland McGrath break; 767e16b2781SRoland McGrath 768e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 769e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 770e16b2781SRoland McGrath if (copy_siginfo_from_user32( 771e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 772e16b2781SRoland McGrath ret = -EFAULT; 773e16b2781SRoland McGrath else 774e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 775e16b2781SRoland McGrath break; 7762225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 7772225a122SSuresh Siddha case PTRACE_GETREGSET: 7782225a122SSuresh Siddha case PTRACE_SETREGSET: 7792225a122SSuresh Siddha { 7802225a122SSuresh Siddha struct iovec kiov; 7812225a122SSuresh Siddha struct compat_iovec __user *uiov = 7822225a122SSuresh Siddha (struct compat_iovec __user *) datap; 7832225a122SSuresh Siddha compat_uptr_t ptr; 7842225a122SSuresh Siddha compat_size_t len; 7852225a122SSuresh Siddha 7862225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 7872225a122SSuresh Siddha return -EFAULT; 7882225a122SSuresh Siddha 7892225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 7902225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 7912225a122SSuresh Siddha return -EFAULT; 7922225a122SSuresh Siddha 7932225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 7942225a122SSuresh Siddha kiov.iov_len = len; 7952225a122SSuresh Siddha 7962225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 7972225a122SSuresh Siddha if (!ret) 7982225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 7992225a122SSuresh Siddha break; 8002225a122SSuresh Siddha } 8012225a122SSuresh Siddha #endif 802e16b2781SRoland McGrath 803032d82d9SRoland McGrath default: 804032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 805032d82d9SRoland McGrath } 806032d82d9SRoland McGrath 807032d82d9SRoland McGrath return ret; 808032d82d9SRoland McGrath } 809c269f196SRoland McGrath 810c269f196SRoland McGrath asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, 811c269f196SRoland McGrath compat_long_t addr, compat_long_t data) 812c269f196SRoland McGrath { 813c269f196SRoland McGrath struct task_struct *child; 814c269f196SRoland McGrath long ret; 815c269f196SRoland McGrath 816c269f196SRoland McGrath /* 817c269f196SRoland McGrath * This lock_kernel fixes a subtle race with suid exec 818c269f196SRoland McGrath */ 819c269f196SRoland McGrath lock_kernel(); 820c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 821c269f196SRoland McGrath ret = ptrace_traceme(); 822c269f196SRoland McGrath goto out; 823c269f196SRoland McGrath } 824c269f196SRoland McGrath 825c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 826c269f196SRoland McGrath if (IS_ERR(child)) { 827c269f196SRoland McGrath ret = PTR_ERR(child); 828c269f196SRoland McGrath goto out; 829c269f196SRoland McGrath } 830c269f196SRoland McGrath 831c269f196SRoland McGrath if (request == PTRACE_ATTACH) { 832c269f196SRoland McGrath ret = ptrace_attach(child); 833c269f196SRoland McGrath /* 834c269f196SRoland McGrath * Some architectures need to do book-keeping after 835c269f196SRoland McGrath * a ptrace attach. 836c269f196SRoland McGrath */ 837c269f196SRoland McGrath if (!ret) 838c269f196SRoland McGrath arch_ptrace_attach(child); 839c269f196SRoland McGrath goto out_put_task_struct; 840c269f196SRoland McGrath } 841c269f196SRoland McGrath 842c269f196SRoland McGrath ret = ptrace_check_attach(child, request == PTRACE_KILL); 843c269f196SRoland McGrath if (!ret) 844c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 845c269f196SRoland McGrath 846c269f196SRoland McGrath out_put_task_struct: 847c269f196SRoland McGrath put_task_struct(child); 848c269f196SRoland McGrath out: 849c269f196SRoland McGrath unlock_kernel(); 850c269f196SRoland McGrath return ret; 851c269f196SRoland McGrath } 85296b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 853