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> 25bf26c018SFrederic Weisbecker #include <linux/hw_breakpoint.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 41e3bd058fSTejun Heo /** 42e3bd058fSTejun Heo * __ptrace_unlink - unlink ptracee and restore its execution state 43e3bd058fSTejun Heo * @child: ptracee to be unlinked 441da177e4SLinus Torvalds * 450e9f0a4aSTejun Heo * Remove @child from the ptrace list, move it back to the original parent, 460e9f0a4aSTejun Heo * and restore the execution state so that it conforms to the group stop 470e9f0a4aSTejun Heo * state. 480e9f0a4aSTejun Heo * 490e9f0a4aSTejun Heo * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer 500e9f0a4aSTejun Heo * exiting. For PTRACE_DETACH, unless the ptracee has been killed between 510e9f0a4aSTejun Heo * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. 520e9f0a4aSTejun Heo * If the ptracer is exiting, the ptracee can be in any state. 530e9f0a4aSTejun Heo * 540e9f0a4aSTejun Heo * After detach, the ptracee should be in a state which conforms to the 550e9f0a4aSTejun Heo * group stop. If the group is stopped or in the process of stopping, the 560e9f0a4aSTejun Heo * ptracee should be put into TASK_STOPPED; otherwise, it should be woken 570e9f0a4aSTejun Heo * up from TASK_TRACED. 580e9f0a4aSTejun Heo * 590e9f0a4aSTejun Heo * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, 600e9f0a4aSTejun Heo * it goes through TRACED -> RUNNING -> STOPPED transition which is similar 610e9f0a4aSTejun Heo * to but in the opposite direction of what happens while attaching to a 620e9f0a4aSTejun Heo * stopped task. However, in this direction, the intermediate RUNNING 630e9f0a4aSTejun Heo * state is not hidden even from the current ptracer and if it immediately 640e9f0a4aSTejun Heo * re-attaches and performs a WNOHANG wait(2), it may fail. 65e3bd058fSTejun Heo * 66e3bd058fSTejun Heo * CONTEXT: 67e3bd058fSTejun Heo * write_lock_irq(tasklist_lock) 681da177e4SLinus Torvalds */ 6936c8b586SIngo Molnar void __ptrace_unlink(struct task_struct *child) 701da177e4SLinus Torvalds { 715ecfbae0SOleg Nesterov BUG_ON(!child->ptrace); 725ecfbae0SOleg Nesterov 731da177e4SLinus Torvalds child->ptrace = 0; 741da177e4SLinus Torvalds child->parent = child->real_parent; 75f470021aSRoland McGrath list_del_init(&child->ptrace_entry); 761da177e4SLinus Torvalds 771da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 780e9f0a4aSTejun Heo 791da177e4SLinus Torvalds /* 80a8f072c1STejun Heo * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and 810e9f0a4aSTejun Heo * @child isn't dead. 821da177e4SLinus Torvalds */ 830e9f0a4aSTejun Heo if (!(child->flags & PF_EXITING) && 840e9f0a4aSTejun Heo (child->signal->flags & SIGNAL_STOP_STOPPED || 850e9f0a4aSTejun Heo child->signal->group_stop_count)) 86a8f072c1STejun Heo child->jobctl |= JOBCTL_STOP_PENDING; 870e9f0a4aSTejun Heo 880e9f0a4aSTejun Heo /* 890e9f0a4aSTejun Heo * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick 900e9f0a4aSTejun Heo * @child in the butt. Note that @resume should be used iff @child 910e9f0a4aSTejun Heo * is in TASK_TRACED; otherwise, we might unduly disrupt 920e9f0a4aSTejun Heo * TASK_KILLABLE sleeps. 930e9f0a4aSTejun Heo */ 94a8f072c1STejun Heo if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) 950e9f0a4aSTejun Heo signal_wake_up(child, task_is_traced(child)); 960e9f0a4aSTejun Heo 971da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 981da177e4SLinus Torvalds } 991da177e4SLinus Torvalds 1001da177e4SLinus Torvalds /* 1011da177e4SLinus Torvalds * Check that we have indeed attached to the thing.. 1021da177e4SLinus Torvalds */ 1031da177e4SLinus Torvalds int ptrace_check_attach(struct task_struct *child, int kill) 1041da177e4SLinus Torvalds { 1051da177e4SLinus Torvalds int ret = -ESRCH; 1061da177e4SLinus Torvalds 1071da177e4SLinus Torvalds /* 1081da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 1091da177e4SLinus Torvalds * possible race where someone else was tracing our child and 1101da177e4SLinus Torvalds * detached between these two checks. After this locked check, 1111da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 1121da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 1131da177e4SLinus Torvalds */ 1141da177e4SLinus Torvalds read_lock(&tasklist_lock); 115c0c0b649SOleg Nesterov if ((child->ptrace & PT_PTRACED) && child->parent == current) { 116c0c0b649SOleg Nesterov /* 117c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 118c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 119c0c0b649SOleg Nesterov */ 1201da177e4SLinus Torvalds spin_lock_irq(&child->sighand->siglock); 121321fb561SOleg Nesterov WARN_ON_ONCE(task_is_stopped(child)); 122321fb561SOleg Nesterov if (task_is_traced(child) || kill) 123321fb561SOleg Nesterov ret = 0; 1241da177e4SLinus Torvalds spin_unlock_irq(&child->sighand->siglock); 1251da177e4SLinus Torvalds } 1261da177e4SLinus Torvalds read_unlock(&tasklist_lock); 1271da177e4SLinus Torvalds 128d9ae90acSOleg Nesterov if (!ret && !kill) 12985ba2d86SRoland McGrath ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; 1301da177e4SLinus Torvalds 1311da177e4SLinus Torvalds /* All systems go.. */ 1321da177e4SLinus Torvalds return ret; 1331da177e4SLinus Torvalds } 1341da177e4SLinus Torvalds 135006ebb40SStephen Smalley int __ptrace_may_access(struct task_struct *task, unsigned int mode) 136ab8d11beSMiklos Szeredi { 137c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 138b6dff3ecSDavid Howells 139df26c40eSEric W. Biederman /* May we inspect the given task? 140df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 141df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 142df26c40eSEric W. Biederman * 143df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 144df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 145df26c40eSEric W. Biederman * or halting the specified task is impossible. 146df26c40eSEric W. Biederman */ 147df26c40eSEric W. Biederman int dumpable = 0; 148df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 149df26c40eSEric W. Biederman if (task == current) 150df26c40eSEric W. Biederman return 0; 151c69e8d9cSDavid Howells rcu_read_lock(); 152c69e8d9cSDavid Howells tcred = __task_cred(task); 1538409cca7SSerge E. Hallyn if (cred->user->user_ns == tcred->user->user_ns && 1548409cca7SSerge E. Hallyn (cred->uid == tcred->euid && 1558409cca7SSerge E. Hallyn cred->uid == tcred->suid && 1568409cca7SSerge E. Hallyn cred->uid == tcred->uid && 1578409cca7SSerge E. Hallyn cred->gid == tcred->egid && 1588409cca7SSerge E. Hallyn cred->gid == tcred->sgid && 1598409cca7SSerge E. Hallyn cred->gid == tcred->gid)) 1608409cca7SSerge E. Hallyn goto ok; 1618409cca7SSerge E. Hallyn if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE)) 1628409cca7SSerge E. Hallyn goto ok; 163c69e8d9cSDavid Howells rcu_read_unlock(); 164ab8d11beSMiklos Szeredi return -EPERM; 1658409cca7SSerge E. Hallyn ok: 166c69e8d9cSDavid Howells rcu_read_unlock(); 167ab8d11beSMiklos Szeredi smp_rmb(); 168df26c40eSEric W. Biederman if (task->mm) 1696c5d5238SKawai, Hidehiro dumpable = get_dumpable(task->mm); 1708409cca7SSerge E. Hallyn if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE)) 171ab8d11beSMiklos Szeredi return -EPERM; 172ab8d11beSMiklos Szeredi 1739e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 174ab8d11beSMiklos Szeredi } 175ab8d11beSMiklos Szeredi 176006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 177ab8d11beSMiklos Szeredi { 178ab8d11beSMiklos Szeredi int err; 179ab8d11beSMiklos Szeredi task_lock(task); 180006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 181ab8d11beSMiklos Szeredi task_unlock(task); 1823a709703SRoland McGrath return !err; 183ab8d11beSMiklos Szeredi } 184ab8d11beSMiklos Szeredi 185e3e89cc5SLinus Torvalds static int ptrace_attach(struct task_struct *task) 1861da177e4SLinus Torvalds { 1871da177e4SLinus Torvalds int retval; 188f5b40e36SLinus Torvalds 189a5cb013dSAl Viro audit_ptrace(task); 190a5cb013dSAl Viro 1911da177e4SLinus Torvalds retval = -EPERM; 192b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 193b79b7ba9SOleg Nesterov goto out; 194bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 195f5b40e36SLinus Torvalds goto out; 196f5b40e36SLinus Torvalds 197f2f0b00aSOleg Nesterov /* 198f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 1995e751e99SDavid Howells * interference; SUID, SGID and LSM creds get determined differently 2005e751e99SDavid Howells * under ptrace. 201d84f4f99SDavid Howells */ 202793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 2039b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 204d84f4f99SDavid Howells goto out; 2054b105cbbSOleg Nesterov 206f5b40e36SLinus Torvalds task_lock(task); 207006ebb40SStephen Smalley retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); 2084b105cbbSOleg Nesterov task_unlock(task); 2091da177e4SLinus Torvalds if (retval) 2104b105cbbSOleg Nesterov goto unlock_creds; 2111da177e4SLinus Torvalds 2124b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 213b79b7ba9SOleg Nesterov retval = -EPERM; 214b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 2154b105cbbSOleg Nesterov goto unlock_tasklist; 216f2f0b00aSOleg Nesterov if (task->ptrace) 2174b105cbbSOleg Nesterov goto unlock_tasklist; 218b79b7ba9SOleg Nesterov 219f2f0b00aSOleg Nesterov task->ptrace = PT_PTRACED; 2208409cca7SSerge E. Hallyn if (task_ns_capable(task, CAP_SYS_PTRACE)) 2211da177e4SLinus Torvalds task->ptrace |= PT_PTRACE_CAP; 2221da177e4SLinus Torvalds 2231da177e4SLinus Torvalds __ptrace_link(task, current); 22433e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 225b79b7ba9SOleg Nesterov 226d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 227d79fdd6dSTejun Heo 228d79fdd6dSTejun Heo /* 229a8f072c1STejun Heo * If the task is already STOPPED, set JOBCTL_STOP_PENDING and 230d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 231d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 232d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 233d79fdd6dSTejun Heo * for the transition to complete before returning from this 234d79fdd6dSTejun Heo * function. 235d79fdd6dSTejun Heo * 236d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 237d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 238d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 239d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 240d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 241d79fdd6dSTejun Heo * 242d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 243d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 244d79fdd6dSTejun Heo */ 245d79fdd6dSTejun Heo if (task_is_stopped(task)) { 246a8f072c1STejun Heo task->jobctl |= JOBCTL_STOP_PENDING | JOBCTL_TRAPPING; 247d79fdd6dSTejun Heo signal_wake_up(task, 1); 248d79fdd6dSTejun Heo } 249d79fdd6dSTejun Heo 250d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 251d79fdd6dSTejun Heo 252b79b7ba9SOleg Nesterov retval = 0; 2534b105cbbSOleg Nesterov unlock_tasklist: 2544b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 2554b105cbbSOleg Nesterov unlock_creds: 2569b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 257f5b40e36SLinus Torvalds out: 2580b1007c3STejun Heo if (!retval) 259d79fdd6dSTejun Heo wait_event(current->signal->wait_chldexit, 260a8f072c1STejun Heo !(task->jobctl & JOBCTL_TRAPPING)); 2611da177e4SLinus Torvalds return retval; 2621da177e4SLinus Torvalds } 2631da177e4SLinus Torvalds 264f2f0b00aSOleg Nesterov /** 265f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 266f2f0b00aSOleg Nesterov * 267f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 268f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 269f2f0b00aSOleg Nesterov */ 270e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 271f2f0b00aSOleg Nesterov { 272f2f0b00aSOleg Nesterov int ret = -EPERM; 273f2f0b00aSOleg Nesterov 2744b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 2754b105cbbSOleg Nesterov /* Are we already being traced? */ 276f2f0b00aSOleg Nesterov if (!current->ptrace) { 277f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 278f2f0b00aSOleg Nesterov /* 279f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 280f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 281f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 282f2f0b00aSOleg Nesterov */ 283f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 284f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 285f2f0b00aSOleg Nesterov __ptrace_link(current, current->real_parent); 286f2f0b00aSOleg Nesterov } 287f2f0b00aSOleg Nesterov } 2884b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 2894b105cbbSOleg Nesterov 290f2f0b00aSOleg Nesterov return ret; 291f2f0b00aSOleg Nesterov } 292f2f0b00aSOleg Nesterov 29339c626aeSOleg Nesterov /* 29439c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 29539c626aeSOleg Nesterov */ 29639c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 29739c626aeSOleg Nesterov { 29839c626aeSOleg Nesterov int ret; 29939c626aeSOleg Nesterov spin_lock(&sigh->siglock); 30039c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 30139c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 30239c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 30339c626aeSOleg Nesterov return ret; 30439c626aeSOleg Nesterov } 30539c626aeSOleg Nesterov 30639c626aeSOleg Nesterov /* 30739c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 30839c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 30939c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 31039c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 31139c626aeSOleg Nesterov * 31239c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 31339c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 31439c626aeSOleg Nesterov * If it should reap itself, return true. 31539c626aeSOleg Nesterov * 316a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 317a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 318a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 319a7f0765eSOleg Nesterov * do_wait(). 32039c626aeSOleg Nesterov */ 32139c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 32239c626aeSOleg Nesterov { 32339c626aeSOleg Nesterov __ptrace_unlink(p); 32439c626aeSOleg Nesterov 32539c626aeSOleg Nesterov if (p->exit_state == EXIT_ZOMBIE) { 32639c626aeSOleg Nesterov if (!task_detached(p) && thread_group_empty(p)) { 32739c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 32839c626aeSOleg Nesterov do_notify_parent(p, p->exit_signal); 329a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 330a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 33139c626aeSOleg Nesterov p->exit_signal = -1; 33239c626aeSOleg Nesterov } 333a7f0765eSOleg Nesterov } 33439c626aeSOleg Nesterov if (task_detached(p)) { 33539c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 33639c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 33739c626aeSOleg Nesterov return true; 33839c626aeSOleg Nesterov } 33939c626aeSOleg Nesterov } 34039c626aeSOleg Nesterov 34139c626aeSOleg Nesterov return false; 34239c626aeSOleg Nesterov } 34339c626aeSOleg Nesterov 344e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 3451da177e4SLinus Torvalds { 34639c626aeSOleg Nesterov bool dead = false; 3474576145cSOleg Nesterov 3487ed20e1aSJesper Juhl if (!valid_signal(data)) 3491da177e4SLinus Torvalds return -EIO; 3501da177e4SLinus Torvalds 3511da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 3521da177e4SLinus Torvalds ptrace_disable(child); 3537d941432SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 3541da177e4SLinus Torvalds 35595c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 35639c626aeSOleg Nesterov /* 35739c626aeSOleg Nesterov * This child can be already killed. Make sure de_thread() or 35839c626aeSOleg Nesterov * our sub-thread doing do_wait() didn't do release_task() yet. 35939c626aeSOleg Nesterov */ 36095c3eb76SOleg Nesterov if (child->ptrace) { 36195c3eb76SOleg Nesterov child->exit_code = data; 3624576145cSOleg Nesterov dead = __ptrace_detach(current, child); 36395c3eb76SOleg Nesterov } 3641da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 3651da177e4SLinus Torvalds 3664576145cSOleg Nesterov if (unlikely(dead)) 3674576145cSOleg Nesterov release_task(child); 3684576145cSOleg Nesterov 3691da177e4SLinus Torvalds return 0; 3701da177e4SLinus Torvalds } 3711da177e4SLinus Torvalds 37239c626aeSOleg Nesterov /* 373c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 374c7e49c14SOleg Nesterov * for writing, and returns with it held too. But note it can release 375c7e49c14SOleg Nesterov * and reacquire the lock. 37639c626aeSOleg Nesterov */ 37739c626aeSOleg Nesterov void exit_ptrace(struct task_struct *tracer) 378c4b5ed25SNamhyung Kim __releases(&tasklist_lock) 379c4b5ed25SNamhyung Kim __acquires(&tasklist_lock) 38039c626aeSOleg Nesterov { 38139c626aeSOleg Nesterov struct task_struct *p, *n; 38239c626aeSOleg Nesterov LIST_HEAD(ptrace_dead); 38339c626aeSOleg Nesterov 384c7e49c14SOleg Nesterov if (likely(list_empty(&tracer->ptraced))) 385c7e49c14SOleg Nesterov return; 386c7e49c14SOleg Nesterov 38739c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 38839c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 38939c626aeSOleg Nesterov list_add(&p->ptrace_entry, &ptrace_dead); 39039c626aeSOleg Nesterov } 39139c626aeSOleg Nesterov 392c7e49c14SOleg Nesterov write_unlock_irq(&tasklist_lock); 39339c626aeSOleg Nesterov BUG_ON(!list_empty(&tracer->ptraced)); 39439c626aeSOleg Nesterov 39539c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { 39639c626aeSOleg Nesterov list_del_init(&p->ptrace_entry); 39739c626aeSOleg Nesterov release_task(p); 39839c626aeSOleg Nesterov } 399c7e49c14SOleg Nesterov 400c7e49c14SOleg Nesterov write_lock_irq(&tasklist_lock); 40139c626aeSOleg Nesterov } 40239c626aeSOleg Nesterov 4031da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 4041da177e4SLinus Torvalds { 4051da177e4SLinus Torvalds int copied = 0; 4061da177e4SLinus Torvalds 4071da177e4SLinus Torvalds while (len > 0) { 4081da177e4SLinus Torvalds char buf[128]; 4091da177e4SLinus Torvalds int this_len, retval; 4101da177e4SLinus Torvalds 4111da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4121da177e4SLinus Torvalds retval = access_process_vm(tsk, src, buf, this_len, 0); 4131da177e4SLinus Torvalds if (!retval) { 4141da177e4SLinus Torvalds if (copied) 4151da177e4SLinus Torvalds break; 4161da177e4SLinus Torvalds return -EIO; 4171da177e4SLinus Torvalds } 4181da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 4191da177e4SLinus Torvalds return -EFAULT; 4201da177e4SLinus Torvalds copied += retval; 4211da177e4SLinus Torvalds src += retval; 4221da177e4SLinus Torvalds dst += retval; 4231da177e4SLinus Torvalds len -= retval; 4241da177e4SLinus Torvalds } 4251da177e4SLinus Torvalds return copied; 4261da177e4SLinus Torvalds } 4271da177e4SLinus Torvalds 4281da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 4291da177e4SLinus Torvalds { 4301da177e4SLinus Torvalds int copied = 0; 4311da177e4SLinus Torvalds 4321da177e4SLinus Torvalds while (len > 0) { 4331da177e4SLinus Torvalds char buf[128]; 4341da177e4SLinus Torvalds int this_len, retval; 4351da177e4SLinus Torvalds 4361da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4371da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 4381da177e4SLinus Torvalds return -EFAULT; 4391da177e4SLinus Torvalds retval = access_process_vm(tsk, dst, buf, this_len, 1); 4401da177e4SLinus Torvalds if (!retval) { 4411da177e4SLinus Torvalds if (copied) 4421da177e4SLinus Torvalds break; 4431da177e4SLinus Torvalds return -EIO; 4441da177e4SLinus Torvalds } 4451da177e4SLinus Torvalds copied += retval; 4461da177e4SLinus Torvalds src += retval; 4471da177e4SLinus Torvalds dst += retval; 4481da177e4SLinus Torvalds len -= retval; 4491da177e4SLinus Torvalds } 4501da177e4SLinus Torvalds return copied; 4511da177e4SLinus Torvalds } 4521da177e4SLinus Torvalds 4534abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 4541da177e4SLinus Torvalds { 4551da177e4SLinus Torvalds child->ptrace &= ~PT_TRACE_MASK; 4561da177e4SLinus Torvalds 4571da177e4SLinus Torvalds if (data & PTRACE_O_TRACESYSGOOD) 4581da177e4SLinus Torvalds child->ptrace |= PT_TRACESYSGOOD; 4591da177e4SLinus Torvalds 4601da177e4SLinus Torvalds if (data & PTRACE_O_TRACEFORK) 4611da177e4SLinus Torvalds child->ptrace |= PT_TRACE_FORK; 4621da177e4SLinus Torvalds 4631da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORK) 4641da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK; 4651da177e4SLinus Torvalds 4661da177e4SLinus Torvalds if (data & PTRACE_O_TRACECLONE) 4671da177e4SLinus Torvalds child->ptrace |= PT_TRACE_CLONE; 4681da177e4SLinus Torvalds 4691da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXEC) 4701da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXEC; 4711da177e4SLinus Torvalds 4721da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORKDONE) 4731da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK_DONE; 4741da177e4SLinus Torvalds 4751da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXIT) 4761da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXIT; 4771da177e4SLinus Torvalds 4781da177e4SLinus Torvalds return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; 4791da177e4SLinus Torvalds } 4801da177e4SLinus Torvalds 481e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 4821da177e4SLinus Torvalds { 483e4961254SOleg Nesterov unsigned long flags; 4841da177e4SLinus Torvalds int error = -ESRCH; 4851da177e4SLinus Torvalds 486e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 4871da177e4SLinus Torvalds error = -EINVAL; 4881da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 489e16b2781SRoland McGrath *info = *child->last_siginfo; 4901da177e4SLinus Torvalds error = 0; 4911da177e4SLinus Torvalds } 492e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 4931da177e4SLinus Torvalds } 4941da177e4SLinus Torvalds return error; 4951da177e4SLinus Torvalds } 4961da177e4SLinus Torvalds 497e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 4981da177e4SLinus Torvalds { 499e4961254SOleg Nesterov unsigned long flags; 5001da177e4SLinus Torvalds int error = -ESRCH; 5011da177e4SLinus Torvalds 502e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5031da177e4SLinus Torvalds error = -EINVAL; 5041da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 505e16b2781SRoland McGrath *child->last_siginfo = *info; 5061da177e4SLinus Torvalds error = 0; 5071da177e4SLinus Torvalds } 508e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5091da177e4SLinus Torvalds } 5101da177e4SLinus Torvalds return error; 5111da177e4SLinus Torvalds } 5121da177e4SLinus Torvalds 51336df29d7SRoland McGrath 51436df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 51536df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 51636df29d7SRoland McGrath #else 51736df29d7SRoland McGrath #define is_singlestep(request) 0 51836df29d7SRoland McGrath #endif 51936df29d7SRoland McGrath 5205b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 5215b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 5225b88abbfSRoland McGrath #else 5235b88abbfSRoland McGrath #define is_singleblock(request) 0 5245b88abbfSRoland McGrath #endif 5255b88abbfSRoland McGrath 52636df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 52736df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 52836df29d7SRoland McGrath #else 52936df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 53036df29d7SRoland McGrath #endif 53136df29d7SRoland McGrath 5324abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 5334abf9869SNamhyung Kim unsigned long data) 53436df29d7SRoland McGrath { 53536df29d7SRoland McGrath if (!valid_signal(data)) 53636df29d7SRoland McGrath return -EIO; 53736df29d7SRoland McGrath 53836df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 53936df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 54036df29d7SRoland McGrath else 54136df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 54236df29d7SRoland McGrath 54336df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 54436df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 54536df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 54636df29d7SRoland McGrath else 54736df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 54836df29d7SRoland McGrath #endif 54936df29d7SRoland McGrath 5505b88abbfSRoland McGrath if (is_singleblock(request)) { 5515b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 5525b88abbfSRoland McGrath return -EIO; 5535b88abbfSRoland McGrath user_enable_block_step(child); 5545b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 55536df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 55636df29d7SRoland McGrath return -EIO; 55736df29d7SRoland McGrath user_enable_single_step(child); 5583a709703SRoland McGrath } else { 55936df29d7SRoland McGrath user_disable_single_step(child); 5603a709703SRoland McGrath } 56136df29d7SRoland McGrath 56236df29d7SRoland McGrath child->exit_code = data; 5630666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 56436df29d7SRoland McGrath 56536df29d7SRoland McGrath return 0; 56636df29d7SRoland McGrath } 56736df29d7SRoland McGrath 5682225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 5692225a122SSuresh Siddha 5702225a122SSuresh Siddha static const struct user_regset * 5712225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 5722225a122SSuresh Siddha { 5732225a122SSuresh Siddha const struct user_regset *regset; 5742225a122SSuresh Siddha int n; 5752225a122SSuresh Siddha 5762225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 5772225a122SSuresh Siddha regset = view->regsets + n; 5782225a122SSuresh Siddha if (regset->core_note_type == type) 5792225a122SSuresh Siddha return regset; 5802225a122SSuresh Siddha } 5812225a122SSuresh Siddha 5822225a122SSuresh Siddha return NULL; 5832225a122SSuresh Siddha } 5842225a122SSuresh Siddha 5852225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 5862225a122SSuresh Siddha struct iovec *kiov) 5872225a122SSuresh Siddha { 5882225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 5892225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 5902225a122SSuresh Siddha int regset_no; 5912225a122SSuresh Siddha 5922225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 593c6a0dd7eSSuresh Siddha return -EINVAL; 5942225a122SSuresh Siddha 5952225a122SSuresh Siddha regset_no = regset - view->regsets; 5962225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 5972225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 5982225a122SSuresh Siddha 5992225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 6002225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 6012225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6022225a122SSuresh Siddha else 6032225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 6042225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6052225a122SSuresh Siddha } 6062225a122SSuresh Siddha 6072225a122SSuresh Siddha #endif 6082225a122SSuresh Siddha 6091da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 6104abf9869SNamhyung Kim unsigned long addr, unsigned long data) 6111da177e4SLinus Torvalds { 6121da177e4SLinus Torvalds int ret = -EIO; 613e16b2781SRoland McGrath siginfo_t siginfo; 6149fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 6159fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 6161da177e4SLinus Torvalds 6171da177e4SLinus Torvalds switch (request) { 61816c3e389SRoland McGrath case PTRACE_PEEKTEXT: 61916c3e389SRoland McGrath case PTRACE_PEEKDATA: 62016c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 62116c3e389SRoland McGrath case PTRACE_POKETEXT: 62216c3e389SRoland McGrath case PTRACE_POKEDATA: 62316c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 62416c3e389SRoland McGrath 6251da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 6261da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 6271da177e4SLinus Torvalds #endif 6281da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 6291da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 6301da177e4SLinus Torvalds break; 6311da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 6329fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 6331da177e4SLinus Torvalds break; 634e16b2781SRoland McGrath 6351da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 636e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 637e16b2781SRoland McGrath if (!ret) 6389fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 6391da177e4SLinus Torvalds break; 640e16b2781SRoland McGrath 6411da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 6429fed81dcSNamhyung Kim if (copy_from_user(&siginfo, datavp, sizeof siginfo)) 643e16b2781SRoland McGrath ret = -EFAULT; 644e16b2781SRoland McGrath else 645e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 6461da177e4SLinus Torvalds break; 647e16b2781SRoland McGrath 6481bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 6491bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 6501bcf5482SAlexey Dobriyan break; 65136df29d7SRoland McGrath 6529c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 6539c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 654e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 6559c1a1259SMike Frysinger unsigned long tmp = 0; 6569c1a1259SMike Frysinger 657e0129ef9SOleg Nesterov ret = -ESRCH; 658e0129ef9SOleg Nesterov if (!mm) 659e0129ef9SOleg Nesterov break; 660e0129ef9SOleg Nesterov 6619c1a1259SMike Frysinger switch (addr) { 6629c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 663e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 6649c1a1259SMike Frysinger break; 6659c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 666e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 6679c1a1259SMike Frysinger break; 6689c1a1259SMike Frysinger default: 6699c1a1259SMike Frysinger break; 6709c1a1259SMike Frysinger } 671e0129ef9SOleg Nesterov mmput(mm); 6729c1a1259SMike Frysinger 6739fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 6749c1a1259SMike Frysinger break; 6759c1a1259SMike Frysinger } 6769c1a1259SMike Frysinger #endif 6779c1a1259SMike Frysinger 67836df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 67936df29d7SRoland McGrath case PTRACE_SINGLESTEP: 68036df29d7SRoland McGrath #endif 6815b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 6825b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 6835b88abbfSRoland McGrath #endif 68436df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 68536df29d7SRoland McGrath case PTRACE_SYSEMU: 68636df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 68736df29d7SRoland McGrath #endif 68836df29d7SRoland McGrath case PTRACE_SYSCALL: 68936df29d7SRoland McGrath case PTRACE_CONT: 69036df29d7SRoland McGrath return ptrace_resume(child, request, data); 69136df29d7SRoland McGrath 69236df29d7SRoland McGrath case PTRACE_KILL: 69336df29d7SRoland McGrath if (child->exit_state) /* already dead */ 69436df29d7SRoland McGrath return 0; 69536df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 69636df29d7SRoland McGrath 6972225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 6982225a122SSuresh Siddha case PTRACE_GETREGSET: 6992225a122SSuresh Siddha case PTRACE_SETREGSET: 7002225a122SSuresh Siddha { 7012225a122SSuresh Siddha struct iovec kiov; 7029fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 7032225a122SSuresh Siddha 7042225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 7052225a122SSuresh Siddha return -EFAULT; 7062225a122SSuresh Siddha 7072225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 7082225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 7092225a122SSuresh Siddha return -EFAULT; 7102225a122SSuresh Siddha 7112225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 7122225a122SSuresh Siddha if (!ret) 7132225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 7142225a122SSuresh Siddha break; 7152225a122SSuresh Siddha } 7162225a122SSuresh Siddha #endif 7171da177e4SLinus Torvalds default: 7181da177e4SLinus Torvalds break; 7191da177e4SLinus Torvalds } 7201da177e4SLinus Torvalds 7211da177e4SLinus Torvalds return ret; 7221da177e4SLinus Torvalds } 723481bed45SChristoph Hellwig 7248053bdd5SOleg Nesterov static struct task_struct *ptrace_get_task_struct(pid_t pid) 7256b9c7ed8SChristoph Hellwig { 7266b9c7ed8SChristoph Hellwig struct task_struct *child; 7276b9c7ed8SChristoph Hellwig 7288053bdd5SOleg Nesterov rcu_read_lock(); 729228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 730481bed45SChristoph Hellwig if (child) 731481bed45SChristoph Hellwig get_task_struct(child); 7328053bdd5SOleg Nesterov rcu_read_unlock(); 733f400e198SSukadev Bhattiprolu 734481bed45SChristoph Hellwig if (!child) 7356b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 7366b9c7ed8SChristoph Hellwig return child; 737481bed45SChristoph Hellwig } 738481bed45SChristoph Hellwig 7390ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 7400ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 7410ac15559SChristoph Hellwig #endif 7420ac15559SChristoph Hellwig 7434abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 7444abf9869SNamhyung Kim unsigned long, data) 745481bed45SChristoph Hellwig { 746481bed45SChristoph Hellwig struct task_struct *child; 747481bed45SChristoph Hellwig long ret; 748481bed45SChristoph Hellwig 7496b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 7506b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 7516ea6dd93SHaavard Skinnemoen if (!ret) 7526ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 753481bed45SChristoph Hellwig goto out; 7546b9c7ed8SChristoph Hellwig } 7556b9c7ed8SChristoph Hellwig 7566b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 7576b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 7586b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 7596b9c7ed8SChristoph Hellwig goto out; 7606b9c7ed8SChristoph Hellwig } 761481bed45SChristoph Hellwig 762481bed45SChristoph Hellwig if (request == PTRACE_ATTACH) { 763481bed45SChristoph Hellwig ret = ptrace_attach(child); 7640ac15559SChristoph Hellwig /* 7650ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 7660ac15559SChristoph Hellwig * a ptrace attach. 7670ac15559SChristoph Hellwig */ 7680ac15559SChristoph Hellwig if (!ret) 7690ac15559SChristoph Hellwig arch_ptrace_attach(child); 770005f18dfSChristoph Hellwig goto out_put_task_struct; 771481bed45SChristoph Hellwig } 772481bed45SChristoph Hellwig 773481bed45SChristoph Hellwig ret = ptrace_check_attach(child, request == PTRACE_KILL); 774481bed45SChristoph Hellwig if (ret < 0) 775481bed45SChristoph Hellwig goto out_put_task_struct; 776481bed45SChristoph Hellwig 777481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 778481bed45SChristoph Hellwig 779481bed45SChristoph Hellwig out_put_task_struct: 780481bed45SChristoph Hellwig put_task_struct(child); 781481bed45SChristoph Hellwig out: 782481bed45SChristoph Hellwig return ret; 783481bed45SChristoph Hellwig } 78476647323SAlexey Dobriyan 7854abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 7864abf9869SNamhyung Kim unsigned long data) 78776647323SAlexey Dobriyan { 78876647323SAlexey Dobriyan unsigned long tmp; 78976647323SAlexey Dobriyan int copied; 79076647323SAlexey Dobriyan 79176647323SAlexey Dobriyan copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); 79276647323SAlexey Dobriyan if (copied != sizeof(tmp)) 79376647323SAlexey Dobriyan return -EIO; 79476647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 79576647323SAlexey Dobriyan } 796f284ce72SAlexey Dobriyan 7974abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 7984abf9869SNamhyung Kim unsigned long data) 799f284ce72SAlexey Dobriyan { 800f284ce72SAlexey Dobriyan int copied; 801f284ce72SAlexey Dobriyan 802f284ce72SAlexey Dobriyan copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); 803f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 804f284ce72SAlexey Dobriyan } 805032d82d9SRoland McGrath 80696b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 807032d82d9SRoland McGrath #include <linux/compat.h> 808032d82d9SRoland McGrath 809032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 810032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 811032d82d9SRoland McGrath { 812032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 813032d82d9SRoland McGrath compat_ulong_t word; 814e16b2781SRoland McGrath siginfo_t siginfo; 815032d82d9SRoland McGrath int ret; 816032d82d9SRoland McGrath 817032d82d9SRoland McGrath switch (request) { 818032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 819032d82d9SRoland McGrath case PTRACE_PEEKDATA: 820032d82d9SRoland McGrath ret = access_process_vm(child, addr, &word, sizeof(word), 0); 821032d82d9SRoland McGrath if (ret != sizeof(word)) 822032d82d9SRoland McGrath ret = -EIO; 823032d82d9SRoland McGrath else 824032d82d9SRoland McGrath ret = put_user(word, datap); 825032d82d9SRoland McGrath break; 826032d82d9SRoland McGrath 827032d82d9SRoland McGrath case PTRACE_POKETEXT: 828032d82d9SRoland McGrath case PTRACE_POKEDATA: 829032d82d9SRoland McGrath ret = access_process_vm(child, addr, &data, sizeof(data), 1); 830032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 831032d82d9SRoland McGrath break; 832032d82d9SRoland McGrath 833032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 834032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 835032d82d9SRoland McGrath break; 836032d82d9SRoland McGrath 837e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 838e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 839e16b2781SRoland McGrath if (!ret) 840e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 841e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 842e16b2781SRoland McGrath &siginfo); 843e16b2781SRoland McGrath break; 844e16b2781SRoland McGrath 845e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 846e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 847e16b2781SRoland McGrath if (copy_siginfo_from_user32( 848e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 849e16b2781SRoland McGrath ret = -EFAULT; 850e16b2781SRoland McGrath else 851e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 852e16b2781SRoland McGrath break; 8532225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8542225a122SSuresh Siddha case PTRACE_GETREGSET: 8552225a122SSuresh Siddha case PTRACE_SETREGSET: 8562225a122SSuresh Siddha { 8572225a122SSuresh Siddha struct iovec kiov; 8582225a122SSuresh Siddha struct compat_iovec __user *uiov = 8592225a122SSuresh Siddha (struct compat_iovec __user *) datap; 8602225a122SSuresh Siddha compat_uptr_t ptr; 8612225a122SSuresh Siddha compat_size_t len; 8622225a122SSuresh Siddha 8632225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 8642225a122SSuresh Siddha return -EFAULT; 8652225a122SSuresh Siddha 8662225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 8672225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 8682225a122SSuresh Siddha return -EFAULT; 8692225a122SSuresh Siddha 8702225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 8712225a122SSuresh Siddha kiov.iov_len = len; 8722225a122SSuresh Siddha 8732225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 8742225a122SSuresh Siddha if (!ret) 8752225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 8762225a122SSuresh Siddha break; 8772225a122SSuresh Siddha } 8782225a122SSuresh Siddha #endif 879e16b2781SRoland McGrath 880032d82d9SRoland McGrath default: 881032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 882032d82d9SRoland McGrath } 883032d82d9SRoland McGrath 884032d82d9SRoland McGrath return ret; 885032d82d9SRoland McGrath } 886c269f196SRoland McGrath 887c269f196SRoland McGrath asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, 888c269f196SRoland McGrath compat_long_t addr, compat_long_t data) 889c269f196SRoland McGrath { 890c269f196SRoland McGrath struct task_struct *child; 891c269f196SRoland McGrath long ret; 892c269f196SRoland McGrath 893c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 894c269f196SRoland McGrath ret = ptrace_traceme(); 895c269f196SRoland McGrath goto out; 896c269f196SRoland McGrath } 897c269f196SRoland McGrath 898c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 899c269f196SRoland McGrath if (IS_ERR(child)) { 900c269f196SRoland McGrath ret = PTR_ERR(child); 901c269f196SRoland McGrath goto out; 902c269f196SRoland McGrath } 903c269f196SRoland McGrath 904c269f196SRoland McGrath if (request == PTRACE_ATTACH) { 905c269f196SRoland McGrath ret = ptrace_attach(child); 906c269f196SRoland McGrath /* 907c269f196SRoland McGrath * Some architectures need to do book-keeping after 908c269f196SRoland McGrath * a ptrace attach. 909c269f196SRoland McGrath */ 910c269f196SRoland McGrath if (!ret) 911c269f196SRoland McGrath arch_ptrace_attach(child); 912c269f196SRoland McGrath goto out_put_task_struct; 913c269f196SRoland McGrath } 914c269f196SRoland McGrath 915c269f196SRoland McGrath ret = ptrace_check_attach(child, request == PTRACE_KILL); 916c269f196SRoland McGrath if (!ret) 917c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 918c269f196SRoland McGrath 919c269f196SRoland McGrath out_put_task_struct: 920c269f196SRoland McGrath put_task_struct(child); 921c269f196SRoland McGrath out: 922c269f196SRoland McGrath return ret; 923c269f196SRoland McGrath } 92496b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 925bf26c018SFrederic Weisbecker 926bf26c018SFrederic Weisbecker #ifdef CONFIG_HAVE_HW_BREAKPOINT 927bf26c018SFrederic Weisbecker int ptrace_get_breakpoints(struct task_struct *tsk) 928bf26c018SFrederic Weisbecker { 929bf26c018SFrederic Weisbecker if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) 930bf26c018SFrederic Weisbecker return 0; 931bf26c018SFrederic Weisbecker 932bf26c018SFrederic Weisbecker return -1; 933bf26c018SFrederic Weisbecker } 934bf26c018SFrederic Weisbecker 935bf26c018SFrederic Weisbecker void ptrace_put_breakpoints(struct task_struct *tsk) 936bf26c018SFrederic Weisbecker { 937bf26c018SFrederic Weisbecker if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) 938bf26c018SFrederic Weisbecker flush_ptrace_hw_breakpoint(tsk); 939bf26c018SFrederic Weisbecker } 940bf26c018SFrederic Weisbecker #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 941