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/ptrace.h> 181da177e4SLinus Torvalds #include <linux/security.h> 197ed20e1aSJesper Juhl #include <linux/signal.h> 20a5cb013dSAl Viro #include <linux/audit.h> 21b488893aSPavel Emelyanov #include <linux/pid_namespace.h> 22f17d30a8SAdrian Bunk #include <linux/syscalls.h> 233a709703SRoland McGrath #include <linux/uaccess.h> 242225a122SSuresh Siddha #include <linux/regset.h> 251da177e4SLinus Torvalds 26bf53de90SMarkus Metzger 27bf53de90SMarkus Metzger /* 281da177e4SLinus Torvalds * ptrace a task: make the debugger its new parent and 291da177e4SLinus Torvalds * move it to the ptrace list. 301da177e4SLinus Torvalds * 311da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 321da177e4SLinus Torvalds */ 3336c8b586SIngo Molnar void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) 341da177e4SLinus Torvalds { 35f470021aSRoland McGrath BUG_ON(!list_empty(&child->ptrace_entry)); 36f470021aSRoland McGrath list_add(&child->ptrace_entry, &new_parent->ptraced); 371da177e4SLinus Torvalds child->parent = new_parent; 381da177e4SLinus Torvalds } 391da177e4SLinus Torvalds 40e3bd058fSTejun Heo /** 41e3bd058fSTejun Heo * __ptrace_unlink - unlink ptracee and restore its execution state 42e3bd058fSTejun Heo * @child: ptracee to be unlinked 43e3bd058fSTejun Heo * 440e9f0a4aSTejun Heo * Remove @child from the ptrace list, move it back to the original parent, 450e9f0a4aSTejun Heo * and restore the execution state so that it conforms to the group stop 460e9f0a4aSTejun Heo * state. 470e9f0a4aSTejun Heo * 480e9f0a4aSTejun Heo * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer 490e9f0a4aSTejun Heo * exiting. For PTRACE_DETACH, unless the ptracee has been killed between 500e9f0a4aSTejun Heo * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. 510e9f0a4aSTejun Heo * If the ptracer is exiting, the ptracee can be in any state. 520e9f0a4aSTejun Heo * 530e9f0a4aSTejun Heo * After detach, the ptracee should be in a state which conforms to the 540e9f0a4aSTejun Heo * group stop. If the group is stopped or in the process of stopping, the 550e9f0a4aSTejun Heo * ptracee should be put into TASK_STOPPED; otherwise, it should be woken 560e9f0a4aSTejun Heo * up from TASK_TRACED. 570e9f0a4aSTejun Heo * 580e9f0a4aSTejun Heo * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, 590e9f0a4aSTejun Heo * it goes through TRACED -> RUNNING -> STOPPED transition which is similar 600e9f0a4aSTejun Heo * to but in the opposite direction of what happens while attaching to a 610e9f0a4aSTejun Heo * stopped task. However, in this direction, the intermediate RUNNING 620e9f0a4aSTejun Heo * state is not hidden even from the current ptracer and if it immediately 630e9f0a4aSTejun Heo * re-attaches and performs a WNOHANG wait(2), it may fail. 64e3bd058fSTejun Heo * 65e3bd058fSTejun Heo * CONTEXT: 66e3bd058fSTejun Heo * write_lock_irq(tasklist_lock) 671da177e4SLinus Torvalds */ 68e3bd058fSTejun Heo void __ptrace_unlink(struct task_struct *child) 691da177e4SLinus Torvalds { 70e3bd058fSTejun Heo BUG_ON(!child->ptrace); 71e3bd058fSTejun Heo 72e3bd058fSTejun Heo child->ptrace = 0; 73e3bd058fSTejun Heo child->parent = child->real_parent; 74e3bd058fSTejun Heo list_del_init(&child->ptrace_entry); 75e3bd058fSTejun Heo 761da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 770e9f0a4aSTejun Heo 781ee11844SOleg Nesterov /* 790e9f0a4aSTejun Heo * Reinstate GROUP_STOP_PENDING if group stop is in effect and 800e9f0a4aSTejun Heo * @child isn't dead. 811ee11844SOleg Nesterov */ 820e9f0a4aSTejun Heo if (!(child->flags & PF_EXITING) && 830e9f0a4aSTejun Heo (child->signal->flags & SIGNAL_STOP_STOPPED || 840e9f0a4aSTejun Heo child->signal->group_stop_count)) 85d79fdd6dSTejun Heo child->group_stop |= GROUP_STOP_PENDING; 860e9f0a4aSTejun Heo 870e9f0a4aSTejun Heo /* 880e9f0a4aSTejun Heo * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick 890e9f0a4aSTejun Heo * @child in the butt. Note that @resume should be used iff @child 900e9f0a4aSTejun Heo * is in TASK_TRACED; otherwise, we might unduly disrupt 910e9f0a4aSTejun Heo * TASK_KILLABLE sleeps. 920e9f0a4aSTejun Heo */ 930e9f0a4aSTejun Heo if (child->group_stop & GROUP_STOP_PENDING || task_is_traced(child)) 940e9f0a4aSTejun Heo signal_wake_up(child, task_is_traced(child)); 950e9f0a4aSTejun Heo 961da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 971da177e4SLinus Torvalds } 981da177e4SLinus Torvalds 991da177e4SLinus Torvalds /* 1001da177e4SLinus Torvalds * Check that we have indeed attached to the thing.. 1011da177e4SLinus Torvalds */ 1021da177e4SLinus Torvalds int ptrace_check_attach(struct task_struct *child, int kill) 1031da177e4SLinus Torvalds { 1041da177e4SLinus Torvalds int ret = -ESRCH; 1051da177e4SLinus Torvalds 1061da177e4SLinus Torvalds /* 1071da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 1081da177e4SLinus Torvalds * possible race where someone else was tracing our child and 1091da177e4SLinus Torvalds * detached between these two checks. After this locked check, 1101da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 1111da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 1121da177e4SLinus Torvalds */ 1131da177e4SLinus Torvalds read_lock(&tasklist_lock); 114c0c0b649SOleg Nesterov if ((child->ptrace & PT_PTRACED) && child->parent == current) { 115c0c0b649SOleg Nesterov /* 116c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 117c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 118c0c0b649SOleg Nesterov */ 1191da177e4SLinus Torvalds spin_lock_irq(&child->sighand->siglock); 120321fb561SOleg Nesterov WARN_ON_ONCE(task_is_stopped(child)); 121321fb561SOleg Nesterov if (task_is_traced(child) || kill) 122321fb561SOleg Nesterov ret = 0; 1231da177e4SLinus Torvalds spin_unlock_irq(&child->sighand->siglock); 1241da177e4SLinus Torvalds } 1251da177e4SLinus Torvalds read_unlock(&tasklist_lock); 1261da177e4SLinus Torvalds 127d9ae90acSOleg Nesterov if (!ret && !kill) 12885ba2d86SRoland McGrath ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; 1291da177e4SLinus Torvalds 1301da177e4SLinus Torvalds /* All systems go.. */ 1311da177e4SLinus Torvalds return ret; 1321da177e4SLinus Torvalds } 1331da177e4SLinus Torvalds 134006ebb40SStephen Smalley int __ptrace_may_access(struct task_struct *task, unsigned int mode) 135ab8d11beSMiklos Szeredi { 136c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 137b6dff3ecSDavid Howells 138df26c40eSEric W. Biederman /* May we inspect the given task? 139df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 140df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 141df26c40eSEric W. Biederman * 142df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 143df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 144df26c40eSEric W. Biederman * or halting the specified task is impossible. 145df26c40eSEric W. Biederman */ 146df26c40eSEric W. Biederman int dumpable = 0; 147df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 148df26c40eSEric W. Biederman if (task == current) 149df26c40eSEric W. Biederman return 0; 150c69e8d9cSDavid Howells rcu_read_lock(); 151c69e8d9cSDavid Howells tcred = __task_cred(task); 152c69e8d9cSDavid Howells if ((cred->uid != tcred->euid || 153c69e8d9cSDavid Howells cred->uid != tcred->suid || 154c69e8d9cSDavid Howells cred->uid != tcred->uid || 155c69e8d9cSDavid Howells cred->gid != tcred->egid || 156c69e8d9cSDavid Howells cred->gid != tcred->sgid || 157c69e8d9cSDavid Howells cred->gid != tcred->gid) && 158c69e8d9cSDavid Howells !capable(CAP_SYS_PTRACE)) { 159c69e8d9cSDavid Howells rcu_read_unlock(); 160ab8d11beSMiklos Szeredi return -EPERM; 161c69e8d9cSDavid Howells } 162c69e8d9cSDavid Howells rcu_read_unlock(); 163ab8d11beSMiklos Szeredi smp_rmb(); 164df26c40eSEric W. Biederman if (task->mm) 1656c5d5238SKawai, Hidehiro dumpable = get_dumpable(task->mm); 166df26c40eSEric W. Biederman if (!dumpable && !capable(CAP_SYS_PTRACE)) 167ab8d11beSMiklos Szeredi return -EPERM; 168ab8d11beSMiklos Szeredi 1699e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 170ab8d11beSMiklos Szeredi } 171ab8d11beSMiklos Szeredi 172006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 173ab8d11beSMiklos Szeredi { 174ab8d11beSMiklos Szeredi int err; 175ab8d11beSMiklos Szeredi task_lock(task); 176006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 177ab8d11beSMiklos Szeredi task_unlock(task); 1783a709703SRoland McGrath return !err; 179ab8d11beSMiklos Szeredi } 180ab8d11beSMiklos Szeredi 181e3e89cc5SLinus Torvalds static int ptrace_attach(struct task_struct *task) 1821da177e4SLinus Torvalds { 183d79fdd6dSTejun Heo bool wait_trap = false; 1841da177e4SLinus Torvalds int retval; 185f5b40e36SLinus Torvalds 186a5cb013dSAl Viro audit_ptrace(task); 187a5cb013dSAl Viro 1881da177e4SLinus Torvalds retval = -EPERM; 189b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 190b79b7ba9SOleg Nesterov goto out; 191bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 192f5b40e36SLinus Torvalds goto out; 193f5b40e36SLinus Torvalds 194f2f0b00aSOleg Nesterov /* 195f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 1965e751e99SDavid Howells * interference; SUID, SGID and LSM creds get determined differently 1975e751e99SDavid Howells * under ptrace. 198d84f4f99SDavid Howells */ 199793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 2009b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 201d84f4f99SDavid Howells goto out; 2024b105cbbSOleg Nesterov 203f5b40e36SLinus Torvalds task_lock(task); 204006ebb40SStephen Smalley retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); 2054b105cbbSOleg Nesterov task_unlock(task); 2061da177e4SLinus Torvalds if (retval) 2074b105cbbSOleg Nesterov goto unlock_creds; 2081da177e4SLinus Torvalds 2094b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 210b79b7ba9SOleg Nesterov retval = -EPERM; 211b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 2124b105cbbSOleg Nesterov goto unlock_tasklist; 213f2f0b00aSOleg Nesterov if (task->ptrace) 2144b105cbbSOleg Nesterov goto unlock_tasklist; 215b79b7ba9SOleg Nesterov 216f2f0b00aSOleg Nesterov task->ptrace = PT_PTRACED; 2171da177e4SLinus Torvalds if (capable(CAP_SYS_PTRACE)) 2181da177e4SLinus Torvalds task->ptrace |= PT_PTRACE_CAP; 2191da177e4SLinus Torvalds 2201da177e4SLinus Torvalds __ptrace_link(task, current); 22133e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 222b79b7ba9SOleg Nesterov 223d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 224d79fdd6dSTejun Heo 225d79fdd6dSTejun Heo /* 226d79fdd6dSTejun Heo * If the task is already STOPPED, set GROUP_STOP_PENDING and 227d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 228d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 229d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 230d79fdd6dSTejun Heo * for the transition to complete before returning from this 231d79fdd6dSTejun Heo * function. 232d79fdd6dSTejun Heo * 233d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 234d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 235d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 236d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 237d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 238d79fdd6dSTejun Heo * 239d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 240d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 241d79fdd6dSTejun Heo */ 242d79fdd6dSTejun Heo if (task_is_stopped(task)) { 243d79fdd6dSTejun Heo task->group_stop |= GROUP_STOP_PENDING | GROUP_STOP_TRAPPING; 244d79fdd6dSTejun Heo signal_wake_up(task, 1); 245d79fdd6dSTejun Heo wait_trap = true; 246d79fdd6dSTejun Heo } 247d79fdd6dSTejun Heo 248d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 249d79fdd6dSTejun Heo 250b79b7ba9SOleg Nesterov retval = 0; 2514b105cbbSOleg Nesterov unlock_tasklist: 2524b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 2534b105cbbSOleg Nesterov unlock_creds: 2549b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 255f5b40e36SLinus Torvalds out: 256d79fdd6dSTejun Heo if (wait_trap) 257d79fdd6dSTejun Heo wait_event(current->signal->wait_chldexit, 258d79fdd6dSTejun Heo !(task->group_stop & GROUP_STOP_TRAPPING)); 2591da177e4SLinus Torvalds return retval; 2601da177e4SLinus Torvalds } 2611da177e4SLinus Torvalds 262f2f0b00aSOleg Nesterov /** 263f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 264f2f0b00aSOleg Nesterov * 265f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 266f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 267f2f0b00aSOleg Nesterov */ 268e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 269f2f0b00aSOleg Nesterov { 270f2f0b00aSOleg Nesterov int ret = -EPERM; 271f2f0b00aSOleg Nesterov 2724b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 2734b105cbbSOleg Nesterov /* Are we already being traced? */ 274f2f0b00aSOleg Nesterov if (!current->ptrace) { 275f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 276f2f0b00aSOleg Nesterov /* 277f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 278f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 279f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 280f2f0b00aSOleg Nesterov */ 281f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 282f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 283f2f0b00aSOleg Nesterov __ptrace_link(current, current->real_parent); 284f2f0b00aSOleg Nesterov } 285f2f0b00aSOleg Nesterov } 2864b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 2874b105cbbSOleg Nesterov 288f2f0b00aSOleg Nesterov return ret; 289f2f0b00aSOleg Nesterov } 290f2f0b00aSOleg Nesterov 29139c626aeSOleg Nesterov /* 29239c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 29339c626aeSOleg Nesterov */ 29439c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 29539c626aeSOleg Nesterov { 29639c626aeSOleg Nesterov int ret; 29739c626aeSOleg Nesterov spin_lock(&sigh->siglock); 29839c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 29939c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 30039c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 30139c626aeSOleg Nesterov return ret; 30239c626aeSOleg Nesterov } 30339c626aeSOleg Nesterov 30439c626aeSOleg Nesterov /* 30539c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 30639c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 30739c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 30839c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 30939c626aeSOleg Nesterov * 31039c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 31139c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 31239c626aeSOleg Nesterov * If it should reap itself, return true. 31339c626aeSOleg Nesterov * 314a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 315a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 316a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 317a7f0765eSOleg Nesterov * do_wait(). 31839c626aeSOleg Nesterov */ 31939c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 32039c626aeSOleg Nesterov { 32139c626aeSOleg Nesterov __ptrace_unlink(p); 32239c626aeSOleg Nesterov 32339c626aeSOleg Nesterov if (p->exit_state == EXIT_ZOMBIE) { 32439c626aeSOleg Nesterov if (!task_detached(p) && thread_group_empty(p)) { 32539c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 32639c626aeSOleg Nesterov do_notify_parent(p, p->exit_signal); 327a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 328a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 32939c626aeSOleg Nesterov p->exit_signal = -1; 33039c626aeSOleg Nesterov } 331a7f0765eSOleg Nesterov } 33239c626aeSOleg Nesterov if (task_detached(p)) { 33339c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 33439c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 33539c626aeSOleg Nesterov return true; 33639c626aeSOleg Nesterov } 33739c626aeSOleg Nesterov } 33839c626aeSOleg Nesterov 33939c626aeSOleg Nesterov return false; 34039c626aeSOleg Nesterov } 34139c626aeSOleg Nesterov 342e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 3431da177e4SLinus Torvalds { 34439c626aeSOleg Nesterov bool dead = false; 3454576145cSOleg Nesterov 3467ed20e1aSJesper Juhl if (!valid_signal(data)) 3471da177e4SLinus Torvalds return -EIO; 3481da177e4SLinus Torvalds 3491da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 3501da177e4SLinus Torvalds ptrace_disable(child); 3517d941432SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 3521da177e4SLinus Torvalds 35395c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 35439c626aeSOleg Nesterov /* 35539c626aeSOleg Nesterov * This child can be already killed. Make sure de_thread() or 35639c626aeSOleg Nesterov * our sub-thread doing do_wait() didn't do release_task() yet. 35739c626aeSOleg Nesterov */ 35895c3eb76SOleg Nesterov if (child->ptrace) { 35995c3eb76SOleg Nesterov child->exit_code = data; 3604576145cSOleg Nesterov dead = __ptrace_detach(current, child); 36195c3eb76SOleg Nesterov } 3621da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 3631da177e4SLinus Torvalds 3644576145cSOleg Nesterov if (unlikely(dead)) 3654576145cSOleg Nesterov release_task(child); 3664576145cSOleg Nesterov 3671da177e4SLinus Torvalds return 0; 3681da177e4SLinus Torvalds } 3691da177e4SLinus Torvalds 37039c626aeSOleg Nesterov /* 371c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 372c7e49c14SOleg Nesterov * for writing, and returns with it held too. But note it can release 373c7e49c14SOleg Nesterov * and reacquire the lock. 37439c626aeSOleg Nesterov */ 37539c626aeSOleg Nesterov void exit_ptrace(struct task_struct *tracer) 376c4b5ed25SNamhyung Kim __releases(&tasklist_lock) 377c4b5ed25SNamhyung Kim __acquires(&tasklist_lock) 37839c626aeSOleg Nesterov { 37939c626aeSOleg Nesterov struct task_struct *p, *n; 38039c626aeSOleg Nesterov LIST_HEAD(ptrace_dead); 38139c626aeSOleg Nesterov 382c7e49c14SOleg Nesterov if (likely(list_empty(&tracer->ptraced))) 383c7e49c14SOleg Nesterov return; 384c7e49c14SOleg Nesterov 38539c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 38639c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 38739c626aeSOleg Nesterov list_add(&p->ptrace_entry, &ptrace_dead); 38839c626aeSOleg Nesterov } 38939c626aeSOleg Nesterov 390c7e49c14SOleg Nesterov write_unlock_irq(&tasklist_lock); 39139c626aeSOleg Nesterov BUG_ON(!list_empty(&tracer->ptraced)); 39239c626aeSOleg Nesterov 39339c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { 39439c626aeSOleg Nesterov list_del_init(&p->ptrace_entry); 39539c626aeSOleg Nesterov release_task(p); 39639c626aeSOleg Nesterov } 397c7e49c14SOleg Nesterov 398c7e49c14SOleg Nesterov write_lock_irq(&tasklist_lock); 39939c626aeSOleg Nesterov } 40039c626aeSOleg Nesterov 4011da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 4021da177e4SLinus Torvalds { 4031da177e4SLinus Torvalds int copied = 0; 4041da177e4SLinus Torvalds 4051da177e4SLinus Torvalds while (len > 0) { 4061da177e4SLinus Torvalds char buf[128]; 4071da177e4SLinus Torvalds int this_len, retval; 4081da177e4SLinus Torvalds 4091da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4101da177e4SLinus Torvalds retval = access_process_vm(tsk, src, buf, this_len, 0); 4111da177e4SLinus Torvalds if (!retval) { 4121da177e4SLinus Torvalds if (copied) 4131da177e4SLinus Torvalds break; 4141da177e4SLinus Torvalds return -EIO; 4151da177e4SLinus Torvalds } 4161da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 4171da177e4SLinus Torvalds return -EFAULT; 4181da177e4SLinus Torvalds copied += retval; 4191da177e4SLinus Torvalds src += retval; 4201da177e4SLinus Torvalds dst += retval; 4211da177e4SLinus Torvalds len -= retval; 4221da177e4SLinus Torvalds } 4231da177e4SLinus Torvalds return copied; 4241da177e4SLinus Torvalds } 4251da177e4SLinus Torvalds 4261da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 4271da177e4SLinus Torvalds { 4281da177e4SLinus Torvalds int copied = 0; 4291da177e4SLinus Torvalds 4301da177e4SLinus Torvalds while (len > 0) { 4311da177e4SLinus Torvalds char buf[128]; 4321da177e4SLinus Torvalds int this_len, retval; 4331da177e4SLinus Torvalds 4341da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4351da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 4361da177e4SLinus Torvalds return -EFAULT; 4371da177e4SLinus Torvalds retval = access_process_vm(tsk, dst, buf, this_len, 1); 4381da177e4SLinus Torvalds if (!retval) { 4391da177e4SLinus Torvalds if (copied) 4401da177e4SLinus Torvalds break; 4411da177e4SLinus Torvalds return -EIO; 4421da177e4SLinus Torvalds } 4431da177e4SLinus Torvalds copied += retval; 4441da177e4SLinus Torvalds src += retval; 4451da177e4SLinus Torvalds dst += retval; 4461da177e4SLinus Torvalds len -= retval; 4471da177e4SLinus Torvalds } 4481da177e4SLinus Torvalds return copied; 4491da177e4SLinus Torvalds } 4501da177e4SLinus Torvalds 4514abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 4521da177e4SLinus Torvalds { 4531da177e4SLinus Torvalds child->ptrace &= ~PT_TRACE_MASK; 4541da177e4SLinus Torvalds 4551da177e4SLinus Torvalds if (data & PTRACE_O_TRACESYSGOOD) 4561da177e4SLinus Torvalds child->ptrace |= PT_TRACESYSGOOD; 4571da177e4SLinus Torvalds 4581da177e4SLinus Torvalds if (data & PTRACE_O_TRACEFORK) 4591da177e4SLinus Torvalds child->ptrace |= PT_TRACE_FORK; 4601da177e4SLinus Torvalds 4611da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORK) 4621da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK; 4631da177e4SLinus Torvalds 4641da177e4SLinus Torvalds if (data & PTRACE_O_TRACECLONE) 4651da177e4SLinus Torvalds child->ptrace |= PT_TRACE_CLONE; 4661da177e4SLinus Torvalds 4671da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXEC) 4681da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXEC; 4691da177e4SLinus Torvalds 4701da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORKDONE) 4711da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK_DONE; 4721da177e4SLinus Torvalds 4731da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXIT) 4741da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXIT; 4751da177e4SLinus Torvalds 4761da177e4SLinus Torvalds return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; 4771da177e4SLinus Torvalds } 4781da177e4SLinus Torvalds 479e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 4801da177e4SLinus Torvalds { 481e4961254SOleg Nesterov unsigned long flags; 4821da177e4SLinus Torvalds int error = -ESRCH; 4831da177e4SLinus Torvalds 484e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 4851da177e4SLinus Torvalds error = -EINVAL; 4861da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 487e16b2781SRoland McGrath *info = *child->last_siginfo; 4881da177e4SLinus Torvalds error = 0; 4891da177e4SLinus Torvalds } 490e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 4911da177e4SLinus Torvalds } 4921da177e4SLinus Torvalds return error; 4931da177e4SLinus Torvalds } 4941da177e4SLinus Torvalds 495e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 4961da177e4SLinus Torvalds { 497e4961254SOleg Nesterov unsigned long flags; 4981da177e4SLinus Torvalds int error = -ESRCH; 4991da177e4SLinus Torvalds 500e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5011da177e4SLinus Torvalds error = -EINVAL; 5021da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 503e16b2781SRoland McGrath *child->last_siginfo = *info; 5041da177e4SLinus Torvalds error = 0; 5051da177e4SLinus Torvalds } 506e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5071da177e4SLinus Torvalds } 5081da177e4SLinus Torvalds return error; 5091da177e4SLinus Torvalds } 5101da177e4SLinus Torvalds 51136df29d7SRoland McGrath 51236df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 51336df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 51436df29d7SRoland McGrath #else 51536df29d7SRoland McGrath #define is_singlestep(request) 0 51636df29d7SRoland McGrath #endif 51736df29d7SRoland McGrath 5185b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 5195b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 5205b88abbfSRoland McGrath #else 5215b88abbfSRoland McGrath #define is_singleblock(request) 0 5225b88abbfSRoland McGrath #endif 5235b88abbfSRoland McGrath 52436df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 52536df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 52636df29d7SRoland McGrath #else 52736df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 52836df29d7SRoland McGrath #endif 52936df29d7SRoland McGrath 5304abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 5314abf9869SNamhyung Kim unsigned long data) 53236df29d7SRoland McGrath { 53336df29d7SRoland McGrath if (!valid_signal(data)) 53436df29d7SRoland McGrath return -EIO; 53536df29d7SRoland McGrath 53636df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 53736df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 53836df29d7SRoland McGrath else 53936df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 54036df29d7SRoland McGrath 54136df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 54236df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 54336df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 54436df29d7SRoland McGrath else 54536df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 54636df29d7SRoland McGrath #endif 54736df29d7SRoland McGrath 5485b88abbfSRoland McGrath if (is_singleblock(request)) { 5495b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 5505b88abbfSRoland McGrath return -EIO; 5515b88abbfSRoland McGrath user_enable_block_step(child); 5525b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 55336df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 55436df29d7SRoland McGrath return -EIO; 55536df29d7SRoland McGrath user_enable_single_step(child); 5563a709703SRoland McGrath } else { 55736df29d7SRoland McGrath user_disable_single_step(child); 5583a709703SRoland McGrath } 55936df29d7SRoland McGrath 56036df29d7SRoland McGrath child->exit_code = data; 56136df29d7SRoland McGrath wake_up_process(child); 56236df29d7SRoland McGrath 56336df29d7SRoland McGrath return 0; 56436df29d7SRoland McGrath } 56536df29d7SRoland McGrath 5662225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 5672225a122SSuresh Siddha 5682225a122SSuresh Siddha static const struct user_regset * 5692225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 5702225a122SSuresh Siddha { 5712225a122SSuresh Siddha const struct user_regset *regset; 5722225a122SSuresh Siddha int n; 5732225a122SSuresh Siddha 5742225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 5752225a122SSuresh Siddha regset = view->regsets + n; 5762225a122SSuresh Siddha if (regset->core_note_type == type) 5772225a122SSuresh Siddha return regset; 5782225a122SSuresh Siddha } 5792225a122SSuresh Siddha 5802225a122SSuresh Siddha return NULL; 5812225a122SSuresh Siddha } 5822225a122SSuresh Siddha 5832225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 5842225a122SSuresh Siddha struct iovec *kiov) 5852225a122SSuresh Siddha { 5862225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 5872225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 5882225a122SSuresh Siddha int regset_no; 5892225a122SSuresh Siddha 5902225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 591c6a0dd7eSSuresh Siddha return -EINVAL; 5922225a122SSuresh Siddha 5932225a122SSuresh Siddha regset_no = regset - view->regsets; 5942225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 5952225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 5962225a122SSuresh Siddha 5972225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 5982225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 5992225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6002225a122SSuresh Siddha else 6012225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 6022225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6032225a122SSuresh Siddha } 6042225a122SSuresh Siddha 6052225a122SSuresh Siddha #endif 6062225a122SSuresh Siddha 6071da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 6084abf9869SNamhyung Kim unsigned long addr, unsigned long data) 6091da177e4SLinus Torvalds { 6101da177e4SLinus Torvalds int ret = -EIO; 611e16b2781SRoland McGrath siginfo_t siginfo; 6129fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 6139fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 6141da177e4SLinus Torvalds 6151da177e4SLinus Torvalds switch (request) { 61616c3e389SRoland McGrath case PTRACE_PEEKTEXT: 61716c3e389SRoland McGrath case PTRACE_PEEKDATA: 61816c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 61916c3e389SRoland McGrath case PTRACE_POKETEXT: 62016c3e389SRoland McGrath case PTRACE_POKEDATA: 62116c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 62216c3e389SRoland McGrath 6231da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 6241da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 6251da177e4SLinus Torvalds #endif 6261da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 6271da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 6281da177e4SLinus Torvalds break; 6291da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 6309fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 6311da177e4SLinus Torvalds break; 632e16b2781SRoland McGrath 6331da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 634e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 635e16b2781SRoland McGrath if (!ret) 6369fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 6371da177e4SLinus Torvalds break; 638e16b2781SRoland McGrath 6391da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 6409fed81dcSNamhyung Kim if (copy_from_user(&siginfo, datavp, sizeof siginfo)) 641e16b2781SRoland McGrath ret = -EFAULT; 642e16b2781SRoland McGrath else 643e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 6441da177e4SLinus Torvalds break; 645e16b2781SRoland McGrath 6461bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 6471bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 6481bcf5482SAlexey Dobriyan break; 64936df29d7SRoland McGrath 6509c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 6519c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 652e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 6539c1a1259SMike Frysinger unsigned long tmp = 0; 6549c1a1259SMike Frysinger 655e0129ef9SOleg Nesterov ret = -ESRCH; 656e0129ef9SOleg Nesterov if (!mm) 657e0129ef9SOleg Nesterov break; 658e0129ef9SOleg Nesterov 6599c1a1259SMike Frysinger switch (addr) { 6609c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 661e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 6629c1a1259SMike Frysinger break; 6639c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 664e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 6659c1a1259SMike Frysinger break; 6669c1a1259SMike Frysinger default: 6679c1a1259SMike Frysinger break; 6689c1a1259SMike Frysinger } 669e0129ef9SOleg Nesterov mmput(mm); 6709c1a1259SMike Frysinger 6719fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 6729c1a1259SMike Frysinger break; 6739c1a1259SMike Frysinger } 6749c1a1259SMike Frysinger #endif 6759c1a1259SMike Frysinger 67636df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 67736df29d7SRoland McGrath case PTRACE_SINGLESTEP: 67836df29d7SRoland McGrath #endif 6795b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 6805b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 6815b88abbfSRoland McGrath #endif 68236df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 68336df29d7SRoland McGrath case PTRACE_SYSEMU: 68436df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 68536df29d7SRoland McGrath #endif 68636df29d7SRoland McGrath case PTRACE_SYSCALL: 68736df29d7SRoland McGrath case PTRACE_CONT: 68836df29d7SRoland McGrath return ptrace_resume(child, request, data); 68936df29d7SRoland McGrath 69036df29d7SRoland McGrath case PTRACE_KILL: 69136df29d7SRoland McGrath if (child->exit_state) /* already dead */ 69236df29d7SRoland McGrath return 0; 69336df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 69436df29d7SRoland McGrath 6952225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 6962225a122SSuresh Siddha case PTRACE_GETREGSET: 6972225a122SSuresh Siddha case PTRACE_SETREGSET: 6982225a122SSuresh Siddha { 6992225a122SSuresh Siddha struct iovec kiov; 7009fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 7012225a122SSuresh Siddha 7022225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 7032225a122SSuresh Siddha return -EFAULT; 7042225a122SSuresh Siddha 7052225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 7062225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 7072225a122SSuresh Siddha return -EFAULT; 7082225a122SSuresh Siddha 7092225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 7102225a122SSuresh Siddha if (!ret) 7112225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 7122225a122SSuresh Siddha break; 7132225a122SSuresh Siddha } 7142225a122SSuresh Siddha #endif 7151da177e4SLinus Torvalds default: 7161da177e4SLinus Torvalds break; 7171da177e4SLinus Torvalds } 7181da177e4SLinus Torvalds 7191da177e4SLinus Torvalds return ret; 7201da177e4SLinus Torvalds } 721481bed45SChristoph Hellwig 7228053bdd5SOleg Nesterov static struct task_struct *ptrace_get_task_struct(pid_t pid) 7236b9c7ed8SChristoph Hellwig { 7246b9c7ed8SChristoph Hellwig struct task_struct *child; 7256b9c7ed8SChristoph Hellwig 7268053bdd5SOleg Nesterov rcu_read_lock(); 727228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 728481bed45SChristoph Hellwig if (child) 729481bed45SChristoph Hellwig get_task_struct(child); 7308053bdd5SOleg Nesterov rcu_read_unlock(); 731f400e198SSukadev Bhattiprolu 732481bed45SChristoph Hellwig if (!child) 7336b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 7346b9c7ed8SChristoph Hellwig return child; 735481bed45SChristoph Hellwig } 736481bed45SChristoph Hellwig 7370ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 7380ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 7390ac15559SChristoph Hellwig #endif 7400ac15559SChristoph Hellwig 7414abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 7424abf9869SNamhyung Kim unsigned long, data) 743481bed45SChristoph Hellwig { 744481bed45SChristoph Hellwig struct task_struct *child; 745481bed45SChristoph Hellwig long ret; 746481bed45SChristoph Hellwig 7476b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 7486b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 7496ea6dd93SHaavard Skinnemoen if (!ret) 7506ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 751481bed45SChristoph Hellwig goto out; 7526b9c7ed8SChristoph Hellwig } 7536b9c7ed8SChristoph Hellwig 7546b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 7556b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 7566b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 7576b9c7ed8SChristoph Hellwig goto out; 7586b9c7ed8SChristoph Hellwig } 759481bed45SChristoph Hellwig 760481bed45SChristoph Hellwig if (request == PTRACE_ATTACH) { 761481bed45SChristoph Hellwig ret = ptrace_attach(child); 7620ac15559SChristoph Hellwig /* 7630ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 7640ac15559SChristoph Hellwig * a ptrace attach. 7650ac15559SChristoph Hellwig */ 7660ac15559SChristoph Hellwig if (!ret) 7670ac15559SChristoph Hellwig arch_ptrace_attach(child); 768005f18dfSChristoph Hellwig goto out_put_task_struct; 769481bed45SChristoph Hellwig } 770481bed45SChristoph Hellwig 771481bed45SChristoph Hellwig ret = ptrace_check_attach(child, request == PTRACE_KILL); 772481bed45SChristoph Hellwig if (ret < 0) 773481bed45SChristoph Hellwig goto out_put_task_struct; 774481bed45SChristoph Hellwig 775481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 776481bed45SChristoph Hellwig 777481bed45SChristoph Hellwig out_put_task_struct: 778481bed45SChristoph Hellwig put_task_struct(child); 779481bed45SChristoph Hellwig out: 780481bed45SChristoph Hellwig return ret; 781481bed45SChristoph Hellwig } 78276647323SAlexey Dobriyan 7834abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 7844abf9869SNamhyung Kim unsigned long data) 78576647323SAlexey Dobriyan { 78676647323SAlexey Dobriyan unsigned long tmp; 78776647323SAlexey Dobriyan int copied; 78876647323SAlexey Dobriyan 78976647323SAlexey Dobriyan copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); 79076647323SAlexey Dobriyan if (copied != sizeof(tmp)) 79176647323SAlexey Dobriyan return -EIO; 79276647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 79376647323SAlexey Dobriyan } 794f284ce72SAlexey Dobriyan 7954abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 7964abf9869SNamhyung Kim unsigned long data) 797f284ce72SAlexey Dobriyan { 798f284ce72SAlexey Dobriyan int copied; 799f284ce72SAlexey Dobriyan 800f284ce72SAlexey Dobriyan copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); 801f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 802f284ce72SAlexey Dobriyan } 803032d82d9SRoland McGrath 80496b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 805032d82d9SRoland McGrath #include <linux/compat.h> 806032d82d9SRoland McGrath 807032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 808032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 809032d82d9SRoland McGrath { 810032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 811032d82d9SRoland McGrath compat_ulong_t word; 812e16b2781SRoland McGrath siginfo_t siginfo; 813032d82d9SRoland McGrath int ret; 814032d82d9SRoland McGrath 815032d82d9SRoland McGrath switch (request) { 816032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 817032d82d9SRoland McGrath case PTRACE_PEEKDATA: 818032d82d9SRoland McGrath ret = access_process_vm(child, addr, &word, sizeof(word), 0); 819032d82d9SRoland McGrath if (ret != sizeof(word)) 820032d82d9SRoland McGrath ret = -EIO; 821032d82d9SRoland McGrath else 822032d82d9SRoland McGrath ret = put_user(word, datap); 823032d82d9SRoland McGrath break; 824032d82d9SRoland McGrath 825032d82d9SRoland McGrath case PTRACE_POKETEXT: 826032d82d9SRoland McGrath case PTRACE_POKEDATA: 827032d82d9SRoland McGrath ret = access_process_vm(child, addr, &data, sizeof(data), 1); 828032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 829032d82d9SRoland McGrath break; 830032d82d9SRoland McGrath 831032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 832032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 833032d82d9SRoland McGrath break; 834032d82d9SRoland McGrath 835e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 836e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 837e16b2781SRoland McGrath if (!ret) 838e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 839e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 840e16b2781SRoland McGrath &siginfo); 841e16b2781SRoland McGrath break; 842e16b2781SRoland McGrath 843e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 844e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 845e16b2781SRoland McGrath if (copy_siginfo_from_user32( 846e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 847e16b2781SRoland McGrath ret = -EFAULT; 848e16b2781SRoland McGrath else 849e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 850e16b2781SRoland McGrath break; 8512225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8522225a122SSuresh Siddha case PTRACE_GETREGSET: 8532225a122SSuresh Siddha case PTRACE_SETREGSET: 8542225a122SSuresh Siddha { 8552225a122SSuresh Siddha struct iovec kiov; 8562225a122SSuresh Siddha struct compat_iovec __user *uiov = 8572225a122SSuresh Siddha (struct compat_iovec __user *) datap; 8582225a122SSuresh Siddha compat_uptr_t ptr; 8592225a122SSuresh Siddha compat_size_t len; 8602225a122SSuresh Siddha 8612225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 8622225a122SSuresh Siddha return -EFAULT; 8632225a122SSuresh Siddha 8642225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 8652225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 8662225a122SSuresh Siddha return -EFAULT; 8672225a122SSuresh Siddha 8682225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 8692225a122SSuresh Siddha kiov.iov_len = len; 8702225a122SSuresh Siddha 8712225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 8722225a122SSuresh Siddha if (!ret) 8732225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 8742225a122SSuresh Siddha break; 8752225a122SSuresh Siddha } 8762225a122SSuresh Siddha #endif 877e16b2781SRoland McGrath 878032d82d9SRoland McGrath default: 879032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 880032d82d9SRoland McGrath } 881032d82d9SRoland McGrath 882032d82d9SRoland McGrath return ret; 883032d82d9SRoland McGrath } 884c269f196SRoland McGrath 885c269f196SRoland McGrath asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, 886c269f196SRoland McGrath compat_long_t addr, compat_long_t data) 887c269f196SRoland McGrath { 888c269f196SRoland McGrath struct task_struct *child; 889c269f196SRoland McGrath long ret; 890c269f196SRoland McGrath 891c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 892c269f196SRoland McGrath ret = ptrace_traceme(); 893c269f196SRoland McGrath goto out; 894c269f196SRoland McGrath } 895c269f196SRoland McGrath 896c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 897c269f196SRoland McGrath if (IS_ERR(child)) { 898c269f196SRoland McGrath ret = PTR_ERR(child); 899c269f196SRoland McGrath goto out; 900c269f196SRoland McGrath } 901c269f196SRoland McGrath 902c269f196SRoland McGrath if (request == PTRACE_ATTACH) { 903c269f196SRoland McGrath ret = ptrace_attach(child); 904c269f196SRoland McGrath /* 905c269f196SRoland McGrath * Some architectures need to do book-keeping after 906c269f196SRoland McGrath * a ptrace attach. 907c269f196SRoland McGrath */ 908c269f196SRoland McGrath if (!ret) 909c269f196SRoland McGrath arch_ptrace_attach(child); 910c269f196SRoland McGrath goto out_put_task_struct; 911c269f196SRoland McGrath } 912c269f196SRoland McGrath 913c269f196SRoland McGrath ret = ptrace_check_attach(child, request == PTRACE_KILL); 914c269f196SRoland McGrath if (!ret) 915c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 916c269f196SRoland McGrath 917c269f196SRoland McGrath out_put_task_struct: 918c269f196SRoland McGrath put_task_struct(child); 919c269f196SRoland McGrath out: 920c269f196SRoland McGrath return ret; 921c269f196SRoland McGrath } 92296b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 923