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 2862c124ffSTejun Heo static int ptrace_trapping_sleep_fn(void *flags) 2962c124ffSTejun Heo { 3062c124ffSTejun Heo schedule(); 3162c124ffSTejun Heo return 0; 3262c124ffSTejun Heo } 3362c124ffSTejun Heo 34bf53de90SMarkus Metzger /* 351da177e4SLinus Torvalds * ptrace a task: make the debugger its new parent and 361da177e4SLinus Torvalds * move it to the ptrace list. 371da177e4SLinus Torvalds * 381da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 391da177e4SLinus Torvalds */ 4036c8b586SIngo Molnar void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) 411da177e4SLinus Torvalds { 42f470021aSRoland McGrath BUG_ON(!list_empty(&child->ptrace_entry)); 43f470021aSRoland McGrath list_add(&child->ptrace_entry, &new_parent->ptraced); 441da177e4SLinus Torvalds child->parent = new_parent; 451da177e4SLinus Torvalds } 461da177e4SLinus Torvalds 47e3bd058fSTejun Heo /** 48e3bd058fSTejun Heo * __ptrace_unlink - unlink ptracee and restore its execution state 49e3bd058fSTejun Heo * @child: ptracee to be unlinked 501da177e4SLinus Torvalds * 510e9f0a4aSTejun Heo * Remove @child from the ptrace list, move it back to the original parent, 520e9f0a4aSTejun Heo * and restore the execution state so that it conforms to the group stop 530e9f0a4aSTejun Heo * state. 540e9f0a4aSTejun Heo * 550e9f0a4aSTejun Heo * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer 560e9f0a4aSTejun Heo * exiting. For PTRACE_DETACH, unless the ptracee has been killed between 570e9f0a4aSTejun Heo * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. 580e9f0a4aSTejun Heo * If the ptracer is exiting, the ptracee can be in any state. 590e9f0a4aSTejun Heo * 600e9f0a4aSTejun Heo * After detach, the ptracee should be in a state which conforms to the 610e9f0a4aSTejun Heo * group stop. If the group is stopped or in the process of stopping, the 620e9f0a4aSTejun Heo * ptracee should be put into TASK_STOPPED; otherwise, it should be woken 630e9f0a4aSTejun Heo * up from TASK_TRACED. 640e9f0a4aSTejun Heo * 650e9f0a4aSTejun Heo * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, 660e9f0a4aSTejun Heo * it goes through TRACED -> RUNNING -> STOPPED transition which is similar 670e9f0a4aSTejun Heo * to but in the opposite direction of what happens while attaching to a 680e9f0a4aSTejun Heo * stopped task. However, in this direction, the intermediate RUNNING 690e9f0a4aSTejun Heo * state is not hidden even from the current ptracer and if it immediately 700e9f0a4aSTejun Heo * re-attaches and performs a WNOHANG wait(2), it may fail. 71e3bd058fSTejun Heo * 72e3bd058fSTejun Heo * CONTEXT: 73e3bd058fSTejun Heo * write_lock_irq(tasklist_lock) 741da177e4SLinus Torvalds */ 7536c8b586SIngo Molnar void __ptrace_unlink(struct task_struct *child) 761da177e4SLinus Torvalds { 775ecfbae0SOleg Nesterov BUG_ON(!child->ptrace); 785ecfbae0SOleg Nesterov 791da177e4SLinus Torvalds child->ptrace = 0; 801da177e4SLinus Torvalds child->parent = child->real_parent; 81f470021aSRoland McGrath list_del_init(&child->ptrace_entry); 821da177e4SLinus Torvalds 831da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 840e9f0a4aSTejun Heo 851da177e4SLinus Torvalds /* 8673ddff2bSTejun Heo * Clear all pending traps and TRAPPING. TRAPPING should be 8773ddff2bSTejun Heo * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. 8873ddff2bSTejun Heo */ 8973ddff2bSTejun Heo task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); 9073ddff2bSTejun Heo task_clear_jobctl_trapping(child); 9173ddff2bSTejun Heo 9273ddff2bSTejun Heo /* 93a8f072c1STejun Heo * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and 940e9f0a4aSTejun Heo * @child isn't dead. 951da177e4SLinus Torvalds */ 960e9f0a4aSTejun Heo if (!(child->flags & PF_EXITING) && 970e9f0a4aSTejun Heo (child->signal->flags & SIGNAL_STOP_STOPPED || 980e9f0a4aSTejun Heo child->signal->group_stop_count)) 99a8f072c1STejun Heo child->jobctl |= JOBCTL_STOP_PENDING; 1000e9f0a4aSTejun Heo 1010e9f0a4aSTejun Heo /* 1020e9f0a4aSTejun Heo * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick 1030e9f0a4aSTejun Heo * @child in the butt. Note that @resume should be used iff @child 1040e9f0a4aSTejun Heo * is in TASK_TRACED; otherwise, we might unduly disrupt 1050e9f0a4aSTejun Heo * TASK_KILLABLE sleeps. 1060e9f0a4aSTejun Heo */ 107a8f072c1STejun Heo if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) 1080e9f0a4aSTejun Heo signal_wake_up(child, task_is_traced(child)); 1090e9f0a4aSTejun Heo 1101da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 1111da177e4SLinus Torvalds } 1121da177e4SLinus Torvalds 113755e276bSTejun Heo /** 114755e276bSTejun Heo * ptrace_check_attach - check whether ptracee is ready for ptrace operation 115755e276bSTejun Heo * @child: ptracee to check for 116755e276bSTejun Heo * @ignore_state: don't check whether @child is currently %TASK_TRACED 117755e276bSTejun Heo * 118755e276bSTejun Heo * Check whether @child is being ptraced by %current and ready for further 119755e276bSTejun Heo * ptrace operations. If @ignore_state is %false, @child also should be in 120755e276bSTejun Heo * %TASK_TRACED state and on return the child is guaranteed to be traced 121755e276bSTejun Heo * and not executing. If @ignore_state is %true, @child can be in any 122755e276bSTejun Heo * state. 123755e276bSTejun Heo * 124755e276bSTejun Heo * CONTEXT: 125755e276bSTejun Heo * Grabs and releases tasklist_lock and @child->sighand->siglock. 126755e276bSTejun Heo * 127755e276bSTejun Heo * RETURNS: 128755e276bSTejun Heo * 0 on success, -ESRCH if %child is not ready. 1291da177e4SLinus Torvalds */ 130755e276bSTejun Heo int ptrace_check_attach(struct task_struct *child, bool ignore_state) 1311da177e4SLinus Torvalds { 1321da177e4SLinus Torvalds int ret = -ESRCH; 1331da177e4SLinus Torvalds 1341da177e4SLinus Torvalds /* 1351da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 1361da177e4SLinus Torvalds * possible race where someone else was tracing our child and 1371da177e4SLinus Torvalds * detached between these two checks. After this locked check, 1381da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 1391da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 1401da177e4SLinus Torvalds */ 1411da177e4SLinus Torvalds read_lock(&tasklist_lock); 142c0c0b649SOleg Nesterov if ((child->ptrace & PT_PTRACED) && child->parent == current) { 143c0c0b649SOleg Nesterov /* 144c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 145c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 146c0c0b649SOleg Nesterov */ 1471da177e4SLinus Torvalds spin_lock_irq(&child->sighand->siglock); 148321fb561SOleg Nesterov WARN_ON_ONCE(task_is_stopped(child)); 149755e276bSTejun Heo if (task_is_traced(child) || ignore_state) 150321fb561SOleg Nesterov ret = 0; 1511da177e4SLinus Torvalds spin_unlock_irq(&child->sighand->siglock); 1521da177e4SLinus Torvalds } 1531da177e4SLinus Torvalds read_unlock(&tasklist_lock); 1541da177e4SLinus Torvalds 155755e276bSTejun Heo if (!ret && !ignore_state) 15685ba2d86SRoland McGrath ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; 1571da177e4SLinus Torvalds 1581da177e4SLinus Torvalds /* All systems go.. */ 1591da177e4SLinus Torvalds return ret; 1601da177e4SLinus Torvalds } 1611da177e4SLinus Torvalds 162006ebb40SStephen Smalley int __ptrace_may_access(struct task_struct *task, unsigned int mode) 163ab8d11beSMiklos Szeredi { 164c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 165b6dff3ecSDavid Howells 166df26c40eSEric W. Biederman /* May we inspect the given task? 167df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 168df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 169df26c40eSEric W. Biederman * 170df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 171df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 172df26c40eSEric W. Biederman * or halting the specified task is impossible. 173df26c40eSEric W. Biederman */ 174df26c40eSEric W. Biederman int dumpable = 0; 175df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 176df26c40eSEric W. Biederman if (task == current) 177df26c40eSEric W. Biederman return 0; 178c69e8d9cSDavid Howells rcu_read_lock(); 179c69e8d9cSDavid Howells tcred = __task_cred(task); 1808409cca7SSerge E. Hallyn if (cred->user->user_ns == tcred->user->user_ns && 1818409cca7SSerge E. Hallyn (cred->uid == tcred->euid && 1828409cca7SSerge E. Hallyn cred->uid == tcred->suid && 1838409cca7SSerge E. Hallyn cred->uid == tcred->uid && 1848409cca7SSerge E. Hallyn cred->gid == tcred->egid && 1858409cca7SSerge E. Hallyn cred->gid == tcred->sgid && 1868409cca7SSerge E. Hallyn cred->gid == tcred->gid)) 1878409cca7SSerge E. Hallyn goto ok; 1888409cca7SSerge E. Hallyn if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE)) 1898409cca7SSerge E. Hallyn goto ok; 190c69e8d9cSDavid Howells rcu_read_unlock(); 191ab8d11beSMiklos Szeredi return -EPERM; 1928409cca7SSerge E. Hallyn ok: 193c69e8d9cSDavid Howells rcu_read_unlock(); 194ab8d11beSMiklos Szeredi smp_rmb(); 195df26c40eSEric W. Biederman if (task->mm) 1966c5d5238SKawai, Hidehiro dumpable = get_dumpable(task->mm); 1978409cca7SSerge E. Hallyn if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE)) 198ab8d11beSMiklos Szeredi return -EPERM; 199ab8d11beSMiklos Szeredi 2009e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 201ab8d11beSMiklos Szeredi } 202ab8d11beSMiklos Szeredi 203006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 204ab8d11beSMiklos Szeredi { 205ab8d11beSMiklos Szeredi int err; 206ab8d11beSMiklos Szeredi task_lock(task); 207006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 208ab8d11beSMiklos Szeredi task_unlock(task); 2093a709703SRoland McGrath return !err; 210ab8d11beSMiklos Szeredi } 211ab8d11beSMiklos Szeredi 212e3e89cc5SLinus Torvalds static int ptrace_attach(struct task_struct *task) 2131da177e4SLinus Torvalds { 2141da177e4SLinus Torvalds int retval; 215f5b40e36SLinus Torvalds 216a5cb013dSAl Viro audit_ptrace(task); 217a5cb013dSAl Viro 2181da177e4SLinus Torvalds retval = -EPERM; 219b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 220b79b7ba9SOleg Nesterov goto out; 221bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 222f5b40e36SLinus Torvalds goto out; 223f5b40e36SLinus Torvalds 224f2f0b00aSOleg Nesterov /* 225f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 2265e751e99SDavid Howells * interference; SUID, SGID and LSM creds get determined differently 2275e751e99SDavid Howells * under ptrace. 228d84f4f99SDavid Howells */ 229793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 2309b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 231d84f4f99SDavid Howells goto out; 2324b105cbbSOleg Nesterov 233f5b40e36SLinus Torvalds task_lock(task); 234006ebb40SStephen Smalley retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); 2354b105cbbSOleg Nesterov task_unlock(task); 2361da177e4SLinus Torvalds if (retval) 2374b105cbbSOleg Nesterov goto unlock_creds; 2381da177e4SLinus Torvalds 2394b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 240b79b7ba9SOleg Nesterov retval = -EPERM; 241b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 2424b105cbbSOleg Nesterov goto unlock_tasklist; 243f2f0b00aSOleg Nesterov if (task->ptrace) 2444b105cbbSOleg Nesterov goto unlock_tasklist; 245b79b7ba9SOleg Nesterov 246f2f0b00aSOleg Nesterov task->ptrace = PT_PTRACED; 2478409cca7SSerge E. Hallyn if (task_ns_capable(task, CAP_SYS_PTRACE)) 2481da177e4SLinus Torvalds task->ptrace |= PT_PTRACE_CAP; 2491da177e4SLinus Torvalds 2501da177e4SLinus Torvalds __ptrace_link(task, current); 25133e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 252b79b7ba9SOleg Nesterov 253d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 254d79fdd6dSTejun Heo 255d79fdd6dSTejun Heo /* 25673ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 257d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 258d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 259d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 260d79fdd6dSTejun Heo * for the transition to complete before returning from this 261d79fdd6dSTejun Heo * function. 262d79fdd6dSTejun Heo * 263d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 264d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 265d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 266d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 267d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 268d79fdd6dSTejun Heo * 269d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 270d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 271d79fdd6dSTejun Heo */ 2727dd3db54STejun Heo if (task_is_stopped(task) && 27373ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 274d79fdd6dSTejun Heo signal_wake_up(task, 1); 275d79fdd6dSTejun Heo 276d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 277d79fdd6dSTejun Heo 278b79b7ba9SOleg Nesterov retval = 0; 2794b105cbbSOleg Nesterov unlock_tasklist: 2804b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 2814b105cbbSOleg Nesterov unlock_creds: 2829b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 283f5b40e36SLinus Torvalds out: 2840b1007c3STejun Heo if (!retval) 28562c124ffSTejun Heo wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, 28662c124ffSTejun Heo ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE); 2871da177e4SLinus Torvalds return retval; 2881da177e4SLinus Torvalds } 2891da177e4SLinus Torvalds 290f2f0b00aSOleg Nesterov /** 291f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 292f2f0b00aSOleg Nesterov * 293f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 294f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 295f2f0b00aSOleg Nesterov */ 296e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 297f2f0b00aSOleg Nesterov { 298f2f0b00aSOleg Nesterov int ret = -EPERM; 299f2f0b00aSOleg Nesterov 3004b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 3014b105cbbSOleg Nesterov /* Are we already being traced? */ 302f2f0b00aSOleg Nesterov if (!current->ptrace) { 303f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 304f2f0b00aSOleg Nesterov /* 305f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 306f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 307f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 308f2f0b00aSOleg Nesterov */ 309f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 310f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 311f2f0b00aSOleg Nesterov __ptrace_link(current, current->real_parent); 312f2f0b00aSOleg Nesterov } 313f2f0b00aSOleg Nesterov } 3144b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3154b105cbbSOleg Nesterov 316f2f0b00aSOleg Nesterov return ret; 317f2f0b00aSOleg Nesterov } 318f2f0b00aSOleg Nesterov 31939c626aeSOleg Nesterov /* 32039c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 32139c626aeSOleg Nesterov */ 32239c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 32339c626aeSOleg Nesterov { 32439c626aeSOleg Nesterov int ret; 32539c626aeSOleg Nesterov spin_lock(&sigh->siglock); 32639c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 32739c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 32839c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 32939c626aeSOleg Nesterov return ret; 33039c626aeSOleg Nesterov } 33139c626aeSOleg Nesterov 33239c626aeSOleg Nesterov /* 33339c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 33439c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 33539c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 33639c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 33739c626aeSOleg Nesterov * 33839c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 33939c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 34039c626aeSOleg Nesterov * If it should reap itself, return true. 34139c626aeSOleg Nesterov * 342a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 343a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 344a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 345a7f0765eSOleg Nesterov * do_wait(). 34639c626aeSOleg Nesterov */ 34739c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 34839c626aeSOleg Nesterov { 34939c626aeSOleg Nesterov __ptrace_unlink(p); 35039c626aeSOleg Nesterov 35139c626aeSOleg Nesterov if (p->exit_state == EXIT_ZOMBIE) { 35239c626aeSOleg Nesterov if (!task_detached(p) && thread_group_empty(p)) { 35339c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 35439c626aeSOleg Nesterov do_notify_parent(p, p->exit_signal); 355a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 356a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 35739c626aeSOleg Nesterov p->exit_signal = -1; 35839c626aeSOleg Nesterov } 359a7f0765eSOleg Nesterov } 36039c626aeSOleg Nesterov if (task_detached(p)) { 36139c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 36239c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 36339c626aeSOleg Nesterov return true; 36439c626aeSOleg Nesterov } 36539c626aeSOleg Nesterov } 36639c626aeSOleg Nesterov 36739c626aeSOleg Nesterov return false; 36839c626aeSOleg Nesterov } 36939c626aeSOleg Nesterov 370e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 3711da177e4SLinus Torvalds { 37239c626aeSOleg Nesterov bool dead = false; 3734576145cSOleg Nesterov 3747ed20e1aSJesper Juhl if (!valid_signal(data)) 3751da177e4SLinus Torvalds return -EIO; 3761da177e4SLinus Torvalds 3771da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 3781da177e4SLinus Torvalds ptrace_disable(child); 3797d941432SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 3801da177e4SLinus Torvalds 38195c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 38239c626aeSOleg Nesterov /* 38339c626aeSOleg Nesterov * This child can be already killed. Make sure de_thread() or 38439c626aeSOleg Nesterov * our sub-thread doing do_wait() didn't do release_task() yet. 38539c626aeSOleg Nesterov */ 38695c3eb76SOleg Nesterov if (child->ptrace) { 38795c3eb76SOleg Nesterov child->exit_code = data; 3884576145cSOleg Nesterov dead = __ptrace_detach(current, child); 38995c3eb76SOleg Nesterov } 3901da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 3911da177e4SLinus Torvalds 3924576145cSOleg Nesterov if (unlikely(dead)) 3934576145cSOleg Nesterov release_task(child); 3944576145cSOleg Nesterov 3951da177e4SLinus Torvalds return 0; 3961da177e4SLinus Torvalds } 3971da177e4SLinus Torvalds 39839c626aeSOleg Nesterov /* 399c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 400c7e49c14SOleg Nesterov * for writing, and returns with it held too. But note it can release 401c7e49c14SOleg Nesterov * and reacquire the lock. 40239c626aeSOleg Nesterov */ 40339c626aeSOleg Nesterov void exit_ptrace(struct task_struct *tracer) 404c4b5ed25SNamhyung Kim __releases(&tasklist_lock) 405c4b5ed25SNamhyung Kim __acquires(&tasklist_lock) 40639c626aeSOleg Nesterov { 40739c626aeSOleg Nesterov struct task_struct *p, *n; 40839c626aeSOleg Nesterov LIST_HEAD(ptrace_dead); 40939c626aeSOleg Nesterov 410c7e49c14SOleg Nesterov if (likely(list_empty(&tracer->ptraced))) 411c7e49c14SOleg Nesterov return; 412c7e49c14SOleg Nesterov 41339c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 41439c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 41539c626aeSOleg Nesterov list_add(&p->ptrace_entry, &ptrace_dead); 41639c626aeSOleg Nesterov } 41739c626aeSOleg Nesterov 418c7e49c14SOleg Nesterov write_unlock_irq(&tasklist_lock); 41939c626aeSOleg Nesterov BUG_ON(!list_empty(&tracer->ptraced)); 42039c626aeSOleg Nesterov 42139c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { 42239c626aeSOleg Nesterov list_del_init(&p->ptrace_entry); 42339c626aeSOleg Nesterov release_task(p); 42439c626aeSOleg Nesterov } 425c7e49c14SOleg Nesterov 426c7e49c14SOleg Nesterov write_lock_irq(&tasklist_lock); 42739c626aeSOleg Nesterov } 42839c626aeSOleg Nesterov 4291da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 4301da177e4SLinus Torvalds { 4311da177e4SLinus Torvalds int copied = 0; 4321da177e4SLinus Torvalds 4331da177e4SLinus Torvalds while (len > 0) { 4341da177e4SLinus Torvalds char buf[128]; 4351da177e4SLinus Torvalds int this_len, retval; 4361da177e4SLinus Torvalds 4371da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4381da177e4SLinus Torvalds retval = access_process_vm(tsk, src, buf, this_len, 0); 4391da177e4SLinus Torvalds if (!retval) { 4401da177e4SLinus Torvalds if (copied) 4411da177e4SLinus Torvalds break; 4421da177e4SLinus Torvalds return -EIO; 4431da177e4SLinus Torvalds } 4441da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 4451da177e4SLinus Torvalds return -EFAULT; 4461da177e4SLinus Torvalds copied += retval; 4471da177e4SLinus Torvalds src += retval; 4481da177e4SLinus Torvalds dst += retval; 4491da177e4SLinus Torvalds len -= retval; 4501da177e4SLinus Torvalds } 4511da177e4SLinus Torvalds return copied; 4521da177e4SLinus Torvalds } 4531da177e4SLinus Torvalds 4541da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 4551da177e4SLinus Torvalds { 4561da177e4SLinus Torvalds int copied = 0; 4571da177e4SLinus Torvalds 4581da177e4SLinus Torvalds while (len > 0) { 4591da177e4SLinus Torvalds char buf[128]; 4601da177e4SLinus Torvalds int this_len, retval; 4611da177e4SLinus Torvalds 4621da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4631da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 4641da177e4SLinus Torvalds return -EFAULT; 4651da177e4SLinus Torvalds retval = access_process_vm(tsk, dst, buf, this_len, 1); 4661da177e4SLinus Torvalds if (!retval) { 4671da177e4SLinus Torvalds if (copied) 4681da177e4SLinus Torvalds break; 4691da177e4SLinus Torvalds return -EIO; 4701da177e4SLinus Torvalds } 4711da177e4SLinus Torvalds copied += retval; 4721da177e4SLinus Torvalds src += retval; 4731da177e4SLinus Torvalds dst += retval; 4741da177e4SLinus Torvalds len -= retval; 4751da177e4SLinus Torvalds } 4761da177e4SLinus Torvalds return copied; 4771da177e4SLinus Torvalds } 4781da177e4SLinus Torvalds 4794abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 4801da177e4SLinus Torvalds { 4811da177e4SLinus Torvalds child->ptrace &= ~PT_TRACE_MASK; 4821da177e4SLinus Torvalds 4831da177e4SLinus Torvalds if (data & PTRACE_O_TRACESYSGOOD) 4841da177e4SLinus Torvalds child->ptrace |= PT_TRACESYSGOOD; 4851da177e4SLinus Torvalds 4861da177e4SLinus Torvalds if (data & PTRACE_O_TRACEFORK) 4871da177e4SLinus Torvalds child->ptrace |= PT_TRACE_FORK; 4881da177e4SLinus Torvalds 4891da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORK) 4901da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK; 4911da177e4SLinus Torvalds 4921da177e4SLinus Torvalds if (data & PTRACE_O_TRACECLONE) 4931da177e4SLinus Torvalds child->ptrace |= PT_TRACE_CLONE; 4941da177e4SLinus Torvalds 4951da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXEC) 4961da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXEC; 4971da177e4SLinus Torvalds 4981da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORKDONE) 4991da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK_DONE; 5001da177e4SLinus Torvalds 5011da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXIT) 5021da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXIT; 5031da177e4SLinus Torvalds 5041da177e4SLinus Torvalds return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; 5051da177e4SLinus Torvalds } 5061da177e4SLinus Torvalds 507e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 5081da177e4SLinus Torvalds { 509e4961254SOleg Nesterov unsigned long flags; 5101da177e4SLinus Torvalds int error = -ESRCH; 5111da177e4SLinus Torvalds 512e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5131da177e4SLinus Torvalds error = -EINVAL; 5141da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 515e16b2781SRoland McGrath *info = *child->last_siginfo; 5161da177e4SLinus Torvalds error = 0; 5171da177e4SLinus Torvalds } 518e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5191da177e4SLinus Torvalds } 5201da177e4SLinus Torvalds return error; 5211da177e4SLinus Torvalds } 5221da177e4SLinus Torvalds 523e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 5241da177e4SLinus Torvalds { 525e4961254SOleg Nesterov unsigned long flags; 5261da177e4SLinus Torvalds int error = -ESRCH; 5271da177e4SLinus Torvalds 528e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5291da177e4SLinus Torvalds error = -EINVAL; 5301da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 531e16b2781SRoland McGrath *child->last_siginfo = *info; 5321da177e4SLinus Torvalds error = 0; 5331da177e4SLinus Torvalds } 534e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5351da177e4SLinus Torvalds } 5361da177e4SLinus Torvalds return error; 5371da177e4SLinus Torvalds } 5381da177e4SLinus Torvalds 53936df29d7SRoland McGrath 54036df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 54136df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 54236df29d7SRoland McGrath #else 54336df29d7SRoland McGrath #define is_singlestep(request) 0 54436df29d7SRoland McGrath #endif 54536df29d7SRoland McGrath 5465b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 5475b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 5485b88abbfSRoland McGrath #else 5495b88abbfSRoland McGrath #define is_singleblock(request) 0 5505b88abbfSRoland McGrath #endif 5515b88abbfSRoland McGrath 55236df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 55336df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 55436df29d7SRoland McGrath #else 55536df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 55636df29d7SRoland McGrath #endif 55736df29d7SRoland McGrath 5584abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 5594abf9869SNamhyung Kim unsigned long data) 56036df29d7SRoland McGrath { 56136df29d7SRoland McGrath if (!valid_signal(data)) 56236df29d7SRoland McGrath return -EIO; 56336df29d7SRoland McGrath 56436df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 56536df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 56636df29d7SRoland McGrath else 56736df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 56836df29d7SRoland McGrath 56936df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 57036df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 57136df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 57236df29d7SRoland McGrath else 57336df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 57436df29d7SRoland McGrath #endif 57536df29d7SRoland McGrath 5765b88abbfSRoland McGrath if (is_singleblock(request)) { 5775b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 5785b88abbfSRoland McGrath return -EIO; 5795b88abbfSRoland McGrath user_enable_block_step(child); 5805b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 58136df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 58236df29d7SRoland McGrath return -EIO; 58336df29d7SRoland McGrath user_enable_single_step(child); 5843a709703SRoland McGrath } else { 58536df29d7SRoland McGrath user_disable_single_step(child); 5863a709703SRoland McGrath } 58736df29d7SRoland McGrath 58836df29d7SRoland McGrath child->exit_code = data; 5890666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 59036df29d7SRoland McGrath 59136df29d7SRoland McGrath return 0; 59236df29d7SRoland McGrath } 59336df29d7SRoland McGrath 5942225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 5952225a122SSuresh Siddha 5962225a122SSuresh Siddha static const struct user_regset * 5972225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 5982225a122SSuresh Siddha { 5992225a122SSuresh Siddha const struct user_regset *regset; 6002225a122SSuresh Siddha int n; 6012225a122SSuresh Siddha 6022225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 6032225a122SSuresh Siddha regset = view->regsets + n; 6042225a122SSuresh Siddha if (regset->core_note_type == type) 6052225a122SSuresh Siddha return regset; 6062225a122SSuresh Siddha } 6072225a122SSuresh Siddha 6082225a122SSuresh Siddha return NULL; 6092225a122SSuresh Siddha } 6102225a122SSuresh Siddha 6112225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 6122225a122SSuresh Siddha struct iovec *kiov) 6132225a122SSuresh Siddha { 6142225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 6152225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 6162225a122SSuresh Siddha int regset_no; 6172225a122SSuresh Siddha 6182225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 619c6a0dd7eSSuresh Siddha return -EINVAL; 6202225a122SSuresh Siddha 6212225a122SSuresh Siddha regset_no = regset - view->regsets; 6222225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 6232225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 6242225a122SSuresh Siddha 6252225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 6262225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 6272225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6282225a122SSuresh Siddha else 6292225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 6302225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6312225a122SSuresh Siddha } 6322225a122SSuresh Siddha 6332225a122SSuresh Siddha #endif 6342225a122SSuresh Siddha 6351da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 6364abf9869SNamhyung Kim unsigned long addr, unsigned long data) 6371da177e4SLinus Torvalds { 6381da177e4SLinus Torvalds int ret = -EIO; 639e16b2781SRoland McGrath siginfo_t siginfo; 6409fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 6419fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 6421da177e4SLinus Torvalds 6431da177e4SLinus Torvalds switch (request) { 64416c3e389SRoland McGrath case PTRACE_PEEKTEXT: 64516c3e389SRoland McGrath case PTRACE_PEEKDATA: 64616c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 64716c3e389SRoland McGrath case PTRACE_POKETEXT: 64816c3e389SRoland McGrath case PTRACE_POKEDATA: 64916c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 65016c3e389SRoland McGrath 6511da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 6521da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 6531da177e4SLinus Torvalds #endif 6541da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 6551da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 6561da177e4SLinus Torvalds break; 6571da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 6589fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 6591da177e4SLinus Torvalds break; 660e16b2781SRoland McGrath 6611da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 662e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 663e16b2781SRoland McGrath if (!ret) 6649fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 6651da177e4SLinus Torvalds break; 666e16b2781SRoland McGrath 6671da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 6689fed81dcSNamhyung Kim if (copy_from_user(&siginfo, datavp, sizeof siginfo)) 669e16b2781SRoland McGrath ret = -EFAULT; 670e16b2781SRoland McGrath else 671e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 6721da177e4SLinus Torvalds break; 673e16b2781SRoland McGrath 6741bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 6751bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 6761bcf5482SAlexey Dobriyan break; 67736df29d7SRoland McGrath 6789c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 6799c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 680e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 6819c1a1259SMike Frysinger unsigned long tmp = 0; 6829c1a1259SMike Frysinger 683e0129ef9SOleg Nesterov ret = -ESRCH; 684e0129ef9SOleg Nesterov if (!mm) 685e0129ef9SOleg Nesterov break; 686e0129ef9SOleg Nesterov 6879c1a1259SMike Frysinger switch (addr) { 6889c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 689e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 6909c1a1259SMike Frysinger break; 6919c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 692e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 6939c1a1259SMike Frysinger break; 6949c1a1259SMike Frysinger default: 6959c1a1259SMike Frysinger break; 6969c1a1259SMike Frysinger } 697e0129ef9SOleg Nesterov mmput(mm); 6989c1a1259SMike Frysinger 6999fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 7009c1a1259SMike Frysinger break; 7019c1a1259SMike Frysinger } 7029c1a1259SMike Frysinger #endif 7039c1a1259SMike Frysinger 70436df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 70536df29d7SRoland McGrath case PTRACE_SINGLESTEP: 70636df29d7SRoland McGrath #endif 7075b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 7085b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 7095b88abbfSRoland McGrath #endif 71036df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 71136df29d7SRoland McGrath case PTRACE_SYSEMU: 71236df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 71336df29d7SRoland McGrath #endif 71436df29d7SRoland McGrath case PTRACE_SYSCALL: 71536df29d7SRoland McGrath case PTRACE_CONT: 71636df29d7SRoland McGrath return ptrace_resume(child, request, data); 71736df29d7SRoland McGrath 71836df29d7SRoland McGrath case PTRACE_KILL: 71936df29d7SRoland McGrath if (child->exit_state) /* already dead */ 72036df29d7SRoland McGrath return 0; 72136df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 72236df29d7SRoland McGrath 7232225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 7242225a122SSuresh Siddha case PTRACE_GETREGSET: 7252225a122SSuresh Siddha case PTRACE_SETREGSET: 7262225a122SSuresh Siddha { 7272225a122SSuresh Siddha struct iovec kiov; 7289fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 7292225a122SSuresh Siddha 7302225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 7312225a122SSuresh Siddha return -EFAULT; 7322225a122SSuresh Siddha 7332225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 7342225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 7352225a122SSuresh Siddha return -EFAULT; 7362225a122SSuresh Siddha 7372225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 7382225a122SSuresh Siddha if (!ret) 7392225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 7402225a122SSuresh Siddha break; 7412225a122SSuresh Siddha } 7422225a122SSuresh Siddha #endif 7431da177e4SLinus Torvalds default: 7441da177e4SLinus Torvalds break; 7451da177e4SLinus Torvalds } 7461da177e4SLinus Torvalds 7471da177e4SLinus Torvalds return ret; 7481da177e4SLinus Torvalds } 749481bed45SChristoph Hellwig 7508053bdd5SOleg Nesterov static struct task_struct *ptrace_get_task_struct(pid_t pid) 7516b9c7ed8SChristoph Hellwig { 7526b9c7ed8SChristoph Hellwig struct task_struct *child; 7536b9c7ed8SChristoph Hellwig 7548053bdd5SOleg Nesterov rcu_read_lock(); 755228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 756481bed45SChristoph Hellwig if (child) 757481bed45SChristoph Hellwig get_task_struct(child); 7588053bdd5SOleg Nesterov rcu_read_unlock(); 759f400e198SSukadev Bhattiprolu 760481bed45SChristoph Hellwig if (!child) 7616b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 7626b9c7ed8SChristoph Hellwig return child; 763481bed45SChristoph Hellwig } 764481bed45SChristoph Hellwig 7650ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 7660ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 7670ac15559SChristoph Hellwig #endif 7680ac15559SChristoph Hellwig 7694abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 7704abf9869SNamhyung Kim unsigned long, data) 771481bed45SChristoph Hellwig { 772481bed45SChristoph Hellwig struct task_struct *child; 773481bed45SChristoph Hellwig long ret; 774481bed45SChristoph Hellwig 7756b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 7766b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 7776ea6dd93SHaavard Skinnemoen if (!ret) 7786ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 779481bed45SChristoph Hellwig goto out; 7806b9c7ed8SChristoph Hellwig } 7816b9c7ed8SChristoph Hellwig 7826b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 7836b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 7846b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 7856b9c7ed8SChristoph Hellwig goto out; 7866b9c7ed8SChristoph Hellwig } 787481bed45SChristoph Hellwig 788481bed45SChristoph Hellwig if (request == PTRACE_ATTACH) { 789481bed45SChristoph Hellwig ret = ptrace_attach(child); 7900ac15559SChristoph Hellwig /* 7910ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 7920ac15559SChristoph Hellwig * a ptrace attach. 7930ac15559SChristoph Hellwig */ 7940ac15559SChristoph Hellwig if (!ret) 7950ac15559SChristoph Hellwig arch_ptrace_attach(child); 796005f18dfSChristoph Hellwig goto out_put_task_struct; 797481bed45SChristoph Hellwig } 798481bed45SChristoph Hellwig 799481bed45SChristoph Hellwig ret = ptrace_check_attach(child, request == PTRACE_KILL); 800481bed45SChristoph Hellwig if (ret < 0) 801481bed45SChristoph Hellwig goto out_put_task_struct; 802481bed45SChristoph Hellwig 803481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 804481bed45SChristoph Hellwig 805481bed45SChristoph Hellwig out_put_task_struct: 806481bed45SChristoph Hellwig put_task_struct(child); 807481bed45SChristoph Hellwig out: 808481bed45SChristoph Hellwig return ret; 809481bed45SChristoph Hellwig } 81076647323SAlexey Dobriyan 8114abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 8124abf9869SNamhyung Kim unsigned long data) 81376647323SAlexey Dobriyan { 81476647323SAlexey Dobriyan unsigned long tmp; 81576647323SAlexey Dobriyan int copied; 81676647323SAlexey Dobriyan 81776647323SAlexey Dobriyan copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); 81876647323SAlexey Dobriyan if (copied != sizeof(tmp)) 81976647323SAlexey Dobriyan return -EIO; 82076647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 82176647323SAlexey Dobriyan } 822f284ce72SAlexey Dobriyan 8234abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 8244abf9869SNamhyung Kim unsigned long data) 825f284ce72SAlexey Dobriyan { 826f284ce72SAlexey Dobriyan int copied; 827f284ce72SAlexey Dobriyan 828f284ce72SAlexey Dobriyan copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); 829f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 830f284ce72SAlexey Dobriyan } 831032d82d9SRoland McGrath 83296b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 833032d82d9SRoland McGrath #include <linux/compat.h> 834032d82d9SRoland McGrath 835032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 836032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 837032d82d9SRoland McGrath { 838032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 839032d82d9SRoland McGrath compat_ulong_t word; 840e16b2781SRoland McGrath siginfo_t siginfo; 841032d82d9SRoland McGrath int ret; 842032d82d9SRoland McGrath 843032d82d9SRoland McGrath switch (request) { 844032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 845032d82d9SRoland McGrath case PTRACE_PEEKDATA: 846032d82d9SRoland McGrath ret = access_process_vm(child, addr, &word, sizeof(word), 0); 847032d82d9SRoland McGrath if (ret != sizeof(word)) 848032d82d9SRoland McGrath ret = -EIO; 849032d82d9SRoland McGrath else 850032d82d9SRoland McGrath ret = put_user(word, datap); 851032d82d9SRoland McGrath break; 852032d82d9SRoland McGrath 853032d82d9SRoland McGrath case PTRACE_POKETEXT: 854032d82d9SRoland McGrath case PTRACE_POKEDATA: 855032d82d9SRoland McGrath ret = access_process_vm(child, addr, &data, sizeof(data), 1); 856032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 857032d82d9SRoland McGrath break; 858032d82d9SRoland McGrath 859032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 860032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 861032d82d9SRoland McGrath break; 862032d82d9SRoland McGrath 863e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 864e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 865e16b2781SRoland McGrath if (!ret) 866e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 867e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 868e16b2781SRoland McGrath &siginfo); 869e16b2781SRoland McGrath break; 870e16b2781SRoland McGrath 871e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 872e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 873e16b2781SRoland McGrath if (copy_siginfo_from_user32( 874e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 875e16b2781SRoland McGrath ret = -EFAULT; 876e16b2781SRoland McGrath else 877e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 878e16b2781SRoland McGrath break; 8792225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8802225a122SSuresh Siddha case PTRACE_GETREGSET: 8812225a122SSuresh Siddha case PTRACE_SETREGSET: 8822225a122SSuresh Siddha { 8832225a122SSuresh Siddha struct iovec kiov; 8842225a122SSuresh Siddha struct compat_iovec __user *uiov = 8852225a122SSuresh Siddha (struct compat_iovec __user *) datap; 8862225a122SSuresh Siddha compat_uptr_t ptr; 8872225a122SSuresh Siddha compat_size_t len; 8882225a122SSuresh Siddha 8892225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 8902225a122SSuresh Siddha return -EFAULT; 8912225a122SSuresh Siddha 8922225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 8932225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 8942225a122SSuresh Siddha return -EFAULT; 8952225a122SSuresh Siddha 8962225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 8972225a122SSuresh Siddha kiov.iov_len = len; 8982225a122SSuresh Siddha 8992225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 9002225a122SSuresh Siddha if (!ret) 9012225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 9022225a122SSuresh Siddha break; 9032225a122SSuresh Siddha } 9042225a122SSuresh Siddha #endif 905e16b2781SRoland McGrath 906032d82d9SRoland McGrath default: 907032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 908032d82d9SRoland McGrath } 909032d82d9SRoland McGrath 910032d82d9SRoland McGrath return ret; 911032d82d9SRoland McGrath } 912c269f196SRoland McGrath 913c269f196SRoland McGrath asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, 914c269f196SRoland McGrath compat_long_t addr, compat_long_t data) 915c269f196SRoland McGrath { 916c269f196SRoland McGrath struct task_struct *child; 917c269f196SRoland McGrath long ret; 918c269f196SRoland McGrath 919c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 920c269f196SRoland McGrath ret = ptrace_traceme(); 921c269f196SRoland McGrath goto out; 922c269f196SRoland McGrath } 923c269f196SRoland McGrath 924c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 925c269f196SRoland McGrath if (IS_ERR(child)) { 926c269f196SRoland McGrath ret = PTR_ERR(child); 927c269f196SRoland McGrath goto out; 928c269f196SRoland McGrath } 929c269f196SRoland McGrath 930c269f196SRoland McGrath if (request == PTRACE_ATTACH) { 931c269f196SRoland McGrath ret = ptrace_attach(child); 932c269f196SRoland McGrath /* 933c269f196SRoland McGrath * Some architectures need to do book-keeping after 934c269f196SRoland McGrath * a ptrace attach. 935c269f196SRoland McGrath */ 936c269f196SRoland McGrath if (!ret) 937c269f196SRoland McGrath arch_ptrace_attach(child); 938c269f196SRoland McGrath goto out_put_task_struct; 939c269f196SRoland McGrath } 940c269f196SRoland McGrath 941c269f196SRoland McGrath ret = ptrace_check_attach(child, request == PTRACE_KILL); 942c269f196SRoland McGrath if (!ret) 943c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 944c269f196SRoland McGrath 945c269f196SRoland McGrath out_put_task_struct: 946c269f196SRoland McGrath put_task_struct(child); 947c269f196SRoland McGrath out: 948c269f196SRoland McGrath return ret; 949c269f196SRoland McGrath } 95096b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 951bf26c018SFrederic Weisbecker 952bf26c018SFrederic Weisbecker #ifdef CONFIG_HAVE_HW_BREAKPOINT 953bf26c018SFrederic Weisbecker int ptrace_get_breakpoints(struct task_struct *tsk) 954bf26c018SFrederic Weisbecker { 955bf26c018SFrederic Weisbecker if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) 956bf26c018SFrederic Weisbecker return 0; 957bf26c018SFrederic Weisbecker 958bf26c018SFrederic Weisbecker return -1; 959bf26c018SFrederic Weisbecker } 960bf26c018SFrederic Weisbecker 961bf26c018SFrederic Weisbecker void ptrace_put_breakpoints(struct task_struct *tsk) 962bf26c018SFrederic Weisbecker { 963bf26c018SFrederic Weisbecker if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) 964bf26c018SFrederic Weisbecker flush_ptrace_hw_breakpoint(tsk); 965bf26c018SFrederic Weisbecker } 966bf26c018SFrederic Weisbecker #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 967