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> 119984de1aSPaul Gortmaker #include <linux/export.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> 26f701e5b7SVladimir Zapolskiy #include <linux/cn_proc.h> 271da177e4SLinus Torvalds 28bf53de90SMarkus Metzger 2962c124ffSTejun Heo static int ptrace_trapping_sleep_fn(void *flags) 3062c124ffSTejun Heo { 3162c124ffSTejun Heo schedule(); 3262c124ffSTejun Heo return 0; 3362c124ffSTejun Heo } 3462c124ffSTejun Heo 35bf53de90SMarkus Metzger /* 361da177e4SLinus Torvalds * ptrace a task: make the debugger its new parent and 371da177e4SLinus Torvalds * move it to the ptrace list. 381da177e4SLinus Torvalds * 391da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 401da177e4SLinus Torvalds */ 4136c8b586SIngo Molnar void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) 421da177e4SLinus Torvalds { 43f470021aSRoland McGrath BUG_ON(!list_empty(&child->ptrace_entry)); 44f470021aSRoland McGrath list_add(&child->ptrace_entry, &new_parent->ptraced); 451da177e4SLinus Torvalds child->parent = new_parent; 461da177e4SLinus Torvalds } 471da177e4SLinus Torvalds 48e3bd058fSTejun Heo /** 49e3bd058fSTejun Heo * __ptrace_unlink - unlink ptracee and restore its execution state 50e3bd058fSTejun Heo * @child: ptracee to be unlinked 511da177e4SLinus Torvalds * 520e9f0a4aSTejun Heo * Remove @child from the ptrace list, move it back to the original parent, 530e9f0a4aSTejun Heo * and restore the execution state so that it conforms to the group stop 540e9f0a4aSTejun Heo * state. 550e9f0a4aSTejun Heo * 560e9f0a4aSTejun Heo * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer 570e9f0a4aSTejun Heo * exiting. For PTRACE_DETACH, unless the ptracee has been killed between 580e9f0a4aSTejun Heo * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. 590e9f0a4aSTejun Heo * If the ptracer is exiting, the ptracee can be in any state. 600e9f0a4aSTejun Heo * 610e9f0a4aSTejun Heo * After detach, the ptracee should be in a state which conforms to the 620e9f0a4aSTejun Heo * group stop. If the group is stopped or in the process of stopping, the 630e9f0a4aSTejun Heo * ptracee should be put into TASK_STOPPED; otherwise, it should be woken 640e9f0a4aSTejun Heo * up from TASK_TRACED. 650e9f0a4aSTejun Heo * 660e9f0a4aSTejun Heo * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, 670e9f0a4aSTejun Heo * it goes through TRACED -> RUNNING -> STOPPED transition which is similar 680e9f0a4aSTejun Heo * to but in the opposite direction of what happens while attaching to a 690e9f0a4aSTejun Heo * stopped task. However, in this direction, the intermediate RUNNING 700e9f0a4aSTejun Heo * state is not hidden even from the current ptracer and if it immediately 710e9f0a4aSTejun Heo * re-attaches and performs a WNOHANG wait(2), it may fail. 72e3bd058fSTejun Heo * 73e3bd058fSTejun Heo * CONTEXT: 74e3bd058fSTejun Heo * write_lock_irq(tasklist_lock) 751da177e4SLinus Torvalds */ 7636c8b586SIngo Molnar void __ptrace_unlink(struct task_struct *child) 771da177e4SLinus Torvalds { 785ecfbae0SOleg Nesterov BUG_ON(!child->ptrace); 795ecfbae0SOleg Nesterov 801da177e4SLinus Torvalds child->ptrace = 0; 811da177e4SLinus Torvalds child->parent = child->real_parent; 82f470021aSRoland McGrath list_del_init(&child->ptrace_entry); 831da177e4SLinus Torvalds 841da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 850e9f0a4aSTejun Heo 861da177e4SLinus Torvalds /* 8773ddff2bSTejun Heo * Clear all pending traps and TRAPPING. TRAPPING should be 8873ddff2bSTejun Heo * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. 8973ddff2bSTejun Heo */ 9073ddff2bSTejun Heo task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); 9173ddff2bSTejun Heo task_clear_jobctl_trapping(child); 9273ddff2bSTejun Heo 9373ddff2bSTejun Heo /* 94a8f072c1STejun Heo * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and 950e9f0a4aSTejun Heo * @child isn't dead. 961da177e4SLinus Torvalds */ 970e9f0a4aSTejun Heo if (!(child->flags & PF_EXITING) && 980e9f0a4aSTejun Heo (child->signal->flags & SIGNAL_STOP_STOPPED || 998a88951bSOleg Nesterov child->signal->group_stop_count)) { 100a8f072c1STejun Heo child->jobctl |= JOBCTL_STOP_PENDING; 1010e9f0a4aSTejun Heo 1020e9f0a4aSTejun Heo /* 1038a88951bSOleg Nesterov * This is only possible if this thread was cloned by the 1048a88951bSOleg Nesterov * traced task running in the stopped group, set the signal 1058a88951bSOleg Nesterov * for the future reports. 1068a88951bSOleg Nesterov * FIXME: we should change ptrace_init_task() to handle this 1078a88951bSOleg Nesterov * case. 1088a88951bSOleg Nesterov */ 1098a88951bSOleg Nesterov if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) 1108a88951bSOleg Nesterov child->jobctl |= SIGSTOP; 1118a88951bSOleg Nesterov } 1128a88951bSOleg Nesterov 1138a88951bSOleg Nesterov /* 1140e9f0a4aSTejun Heo * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick 1150e9f0a4aSTejun Heo * @child in the butt. Note that @resume should be used iff @child 1160e9f0a4aSTejun Heo * is in TASK_TRACED; otherwise, we might unduly disrupt 1170e9f0a4aSTejun Heo * TASK_KILLABLE sleeps. 1180e9f0a4aSTejun Heo */ 119a8f072c1STejun Heo if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) 1200e9f0a4aSTejun Heo signal_wake_up(child, task_is_traced(child)); 1210e9f0a4aSTejun Heo 1221da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 1231da177e4SLinus Torvalds } 1241da177e4SLinus Torvalds 125755e276bSTejun Heo /** 126755e276bSTejun Heo * ptrace_check_attach - check whether ptracee is ready for ptrace operation 127755e276bSTejun Heo * @child: ptracee to check for 128755e276bSTejun Heo * @ignore_state: don't check whether @child is currently %TASK_TRACED 129755e276bSTejun Heo * 130755e276bSTejun Heo * Check whether @child is being ptraced by %current and ready for further 131755e276bSTejun Heo * ptrace operations. If @ignore_state is %false, @child also should be in 132755e276bSTejun Heo * %TASK_TRACED state and on return the child is guaranteed to be traced 133755e276bSTejun Heo * and not executing. If @ignore_state is %true, @child can be in any 134755e276bSTejun Heo * state. 135755e276bSTejun Heo * 136755e276bSTejun Heo * CONTEXT: 137755e276bSTejun Heo * Grabs and releases tasklist_lock and @child->sighand->siglock. 138755e276bSTejun Heo * 139755e276bSTejun Heo * RETURNS: 140755e276bSTejun Heo * 0 on success, -ESRCH if %child is not ready. 1411da177e4SLinus Torvalds */ 142755e276bSTejun Heo int ptrace_check_attach(struct task_struct *child, bool ignore_state) 1431da177e4SLinus Torvalds { 1441da177e4SLinus Torvalds int ret = -ESRCH; 1451da177e4SLinus Torvalds 1461da177e4SLinus Torvalds /* 1471da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 1481da177e4SLinus Torvalds * possible race where someone else was tracing our child and 1491da177e4SLinus Torvalds * detached between these two checks. After this locked check, 1501da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 1511da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 1521da177e4SLinus Torvalds */ 1531da177e4SLinus Torvalds read_lock(&tasklist_lock); 154c0c0b649SOleg Nesterov if ((child->ptrace & PT_PTRACED) && child->parent == current) { 155c0c0b649SOleg Nesterov /* 156c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 157c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 158c0c0b649SOleg Nesterov */ 1591da177e4SLinus Torvalds spin_lock_irq(&child->sighand->siglock); 160321fb561SOleg Nesterov WARN_ON_ONCE(task_is_stopped(child)); 161544b2c91STejun Heo if (ignore_state || (task_is_traced(child) && 162544b2c91STejun Heo !(child->jobctl & JOBCTL_LISTENING))) 163321fb561SOleg Nesterov ret = 0; 1641da177e4SLinus Torvalds spin_unlock_irq(&child->sighand->siglock); 1651da177e4SLinus Torvalds } 1661da177e4SLinus Torvalds read_unlock(&tasklist_lock); 1671da177e4SLinus Torvalds 168755e276bSTejun Heo if (!ret && !ignore_state) 16985ba2d86SRoland McGrath ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; 1701da177e4SLinus Torvalds 1711da177e4SLinus Torvalds /* All systems go.. */ 1721da177e4SLinus Torvalds return ret; 1731da177e4SLinus Torvalds } 1741da177e4SLinus Torvalds 17569f594a3SEric Paris static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) 17669f594a3SEric Paris { 17769f594a3SEric Paris if (mode & PTRACE_MODE_NOAUDIT) 17869f594a3SEric Paris return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); 17969f594a3SEric Paris else 18069f594a3SEric Paris return has_ns_capability(current, ns, CAP_SYS_PTRACE); 18169f594a3SEric Paris } 18269f594a3SEric Paris 183006ebb40SStephen Smalley int __ptrace_may_access(struct task_struct *task, unsigned int mode) 184ab8d11beSMiklos Szeredi { 185c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 186b6dff3ecSDavid Howells 187df26c40eSEric W. Biederman /* May we inspect the given task? 188df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 189df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 190df26c40eSEric W. Biederman * 191df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 192df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 193df26c40eSEric W. Biederman * or halting the specified task is impossible. 194df26c40eSEric W. Biederman */ 195df26c40eSEric W. Biederman int dumpable = 0; 196df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 197df26c40eSEric W. Biederman if (task == current) 198df26c40eSEric W. Biederman return 0; 199c69e8d9cSDavid Howells rcu_read_lock(); 200c69e8d9cSDavid Howells tcred = __task_cred(task); 2018409cca7SSerge E. Hallyn if (cred->user->user_ns == tcred->user->user_ns && 2028409cca7SSerge E. Hallyn (cred->uid == tcred->euid && 2038409cca7SSerge E. Hallyn cred->uid == tcred->suid && 2048409cca7SSerge E. Hallyn cred->uid == tcred->uid && 2058409cca7SSerge E. Hallyn cred->gid == tcred->egid && 2068409cca7SSerge E. Hallyn cred->gid == tcred->sgid && 2078409cca7SSerge E. Hallyn cred->gid == tcred->gid)) 2088409cca7SSerge E. Hallyn goto ok; 20969f594a3SEric Paris if (ptrace_has_cap(tcred->user->user_ns, mode)) 2108409cca7SSerge E. Hallyn goto ok; 211c69e8d9cSDavid Howells rcu_read_unlock(); 212ab8d11beSMiklos Szeredi return -EPERM; 2138409cca7SSerge E. Hallyn ok: 214c69e8d9cSDavid Howells rcu_read_unlock(); 215ab8d11beSMiklos Szeredi smp_rmb(); 216df26c40eSEric W. Biederman if (task->mm) 2176c5d5238SKawai, Hidehiro dumpable = get_dumpable(task->mm); 21869f594a3SEric Paris if (!dumpable && !ptrace_has_cap(task_user_ns(task), mode)) 219ab8d11beSMiklos Szeredi return -EPERM; 220ab8d11beSMiklos Szeredi 2219e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 222ab8d11beSMiklos Szeredi } 223ab8d11beSMiklos Szeredi 224006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 225ab8d11beSMiklos Szeredi { 226ab8d11beSMiklos Szeredi int err; 227ab8d11beSMiklos Szeredi task_lock(task); 228006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 229ab8d11beSMiklos Szeredi task_unlock(task); 2303a709703SRoland McGrath return !err; 231ab8d11beSMiklos Szeredi } 232ab8d11beSMiklos Szeredi 2333544d72aSTejun Heo static int ptrace_attach(struct task_struct *task, long request, 2343544d72aSTejun Heo unsigned long flags) 2351da177e4SLinus Torvalds { 2363544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 2371da177e4SLinus Torvalds int retval; 238f5b40e36SLinus Torvalds 2393544d72aSTejun Heo /* 2403544d72aSTejun Heo * SEIZE will enable new ptrace behaviors which will be implemented 2413544d72aSTejun Heo * gradually. SEIZE_DEVEL is used to prevent applications 2423544d72aSTejun Heo * expecting full SEIZE behaviors trapping on kernel commits which 2433544d72aSTejun Heo * are still in the process of implementing them. 2443544d72aSTejun Heo * 2453544d72aSTejun Heo * Only test programs for new ptrace behaviors being implemented 2463544d72aSTejun Heo * should set SEIZE_DEVEL. If unset, SEIZE will fail with -EIO. 2473544d72aSTejun Heo * 2483544d72aSTejun Heo * Once SEIZE behaviors are completely implemented, this flag and 2493544d72aSTejun Heo * the following test will be removed. 2503544d72aSTejun Heo */ 2513544d72aSTejun Heo retval = -EIO; 2523544d72aSTejun Heo if (seize && !(flags & PTRACE_SEIZE_DEVEL)) 2533544d72aSTejun Heo goto out; 2543544d72aSTejun Heo 255a5cb013dSAl Viro audit_ptrace(task); 256a5cb013dSAl Viro 2571da177e4SLinus Torvalds retval = -EPERM; 258b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 259b79b7ba9SOleg Nesterov goto out; 260bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 261f5b40e36SLinus Torvalds goto out; 262f5b40e36SLinus Torvalds 263f2f0b00aSOleg Nesterov /* 264f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 2655e751e99SDavid Howells * interference; SUID, SGID and LSM creds get determined differently 2665e751e99SDavid Howells * under ptrace. 267d84f4f99SDavid Howells */ 268793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 2699b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 270d84f4f99SDavid Howells goto out; 2714b105cbbSOleg Nesterov 272f5b40e36SLinus Torvalds task_lock(task); 273006ebb40SStephen Smalley retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); 2744b105cbbSOleg Nesterov task_unlock(task); 2751da177e4SLinus Torvalds if (retval) 2764b105cbbSOleg Nesterov goto unlock_creds; 2771da177e4SLinus Torvalds 2784b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 279b79b7ba9SOleg Nesterov retval = -EPERM; 280b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 2814b105cbbSOleg Nesterov goto unlock_tasklist; 282f2f0b00aSOleg Nesterov if (task->ptrace) 2834b105cbbSOleg Nesterov goto unlock_tasklist; 284b79b7ba9SOleg Nesterov 285f2f0b00aSOleg Nesterov task->ptrace = PT_PTRACED; 2863544d72aSTejun Heo if (seize) 2873544d72aSTejun Heo task->ptrace |= PT_SEIZED; 288f1c84daeSEric Paris if (ns_capable(task_user_ns(task), CAP_SYS_PTRACE)) 2891da177e4SLinus Torvalds task->ptrace |= PT_PTRACE_CAP; 2901da177e4SLinus Torvalds 2911da177e4SLinus Torvalds __ptrace_link(task, current); 2923544d72aSTejun Heo 2933544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 2943544d72aSTejun Heo if (!seize) 29533e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 296b79b7ba9SOleg Nesterov 297d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 298d79fdd6dSTejun Heo 299d79fdd6dSTejun Heo /* 30073ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 301d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 302d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 303d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 304d79fdd6dSTejun Heo * for the transition to complete before returning from this 305d79fdd6dSTejun Heo * function. 306d79fdd6dSTejun Heo * 307d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 308d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 309d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 310d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 311d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 312d79fdd6dSTejun Heo * 313d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 314d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 315d79fdd6dSTejun Heo */ 3167dd3db54STejun Heo if (task_is_stopped(task) && 31773ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 318d79fdd6dSTejun Heo signal_wake_up(task, 1); 319d79fdd6dSTejun Heo 320d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 321d79fdd6dSTejun Heo 322b79b7ba9SOleg Nesterov retval = 0; 3234b105cbbSOleg Nesterov unlock_tasklist: 3244b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3254b105cbbSOleg Nesterov unlock_creds: 3269b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 327f5b40e36SLinus Torvalds out: 328f701e5b7SVladimir Zapolskiy if (!retval) { 32962c124ffSTejun Heo wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, 33062c124ffSTejun Heo ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE); 331f701e5b7SVladimir Zapolskiy proc_ptrace_connector(task, PTRACE_ATTACH); 332f701e5b7SVladimir Zapolskiy } 333f701e5b7SVladimir Zapolskiy 3341da177e4SLinus Torvalds return retval; 3351da177e4SLinus Torvalds } 3361da177e4SLinus Torvalds 337f2f0b00aSOleg Nesterov /** 338f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 339f2f0b00aSOleg Nesterov * 340f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 341f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 342f2f0b00aSOleg Nesterov */ 343e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 344f2f0b00aSOleg Nesterov { 345f2f0b00aSOleg Nesterov int ret = -EPERM; 346f2f0b00aSOleg Nesterov 3474b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 3484b105cbbSOleg Nesterov /* Are we already being traced? */ 349f2f0b00aSOleg Nesterov if (!current->ptrace) { 350f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 351f2f0b00aSOleg Nesterov /* 352f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 353f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 354f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 355f2f0b00aSOleg Nesterov */ 356f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 357f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 358f2f0b00aSOleg Nesterov __ptrace_link(current, current->real_parent); 359f2f0b00aSOleg Nesterov } 360f2f0b00aSOleg Nesterov } 3614b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3624b105cbbSOleg Nesterov 363f2f0b00aSOleg Nesterov return ret; 364f2f0b00aSOleg Nesterov } 365f2f0b00aSOleg Nesterov 36639c626aeSOleg Nesterov /* 36739c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 36839c626aeSOleg Nesterov */ 36939c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 37039c626aeSOleg Nesterov { 37139c626aeSOleg Nesterov int ret; 37239c626aeSOleg Nesterov spin_lock(&sigh->siglock); 37339c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 37439c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 37539c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 37639c626aeSOleg Nesterov return ret; 37739c626aeSOleg Nesterov } 37839c626aeSOleg Nesterov 37939c626aeSOleg Nesterov /* 38039c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 38139c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 38239c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 38339c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 38439c626aeSOleg Nesterov * 38539c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 38639c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 38739c626aeSOleg Nesterov * If it should reap itself, return true. 38839c626aeSOleg Nesterov * 389a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 390a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 391a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 392a7f0765eSOleg Nesterov * do_wait(). 39339c626aeSOleg Nesterov */ 39439c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 39539c626aeSOleg Nesterov { 3969843a1e9SOleg Nesterov bool dead; 3979843a1e9SOleg Nesterov 39839c626aeSOleg Nesterov __ptrace_unlink(p); 39939c626aeSOleg Nesterov 4009843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 4019843a1e9SOleg Nesterov return false; 4029843a1e9SOleg Nesterov 4039843a1e9SOleg Nesterov dead = !thread_group_leader(p); 4049843a1e9SOleg Nesterov 4059843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 40639c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 4079843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 408a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 409a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 4109843a1e9SOleg Nesterov dead = true; 41139c626aeSOleg Nesterov } 412a7f0765eSOleg Nesterov } 41339c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 4149843a1e9SOleg Nesterov if (dead) 41539c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 4169843a1e9SOleg Nesterov return dead; 41739c626aeSOleg Nesterov } 41839c626aeSOleg Nesterov 419e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 4201da177e4SLinus Torvalds { 42139c626aeSOleg Nesterov bool dead = false; 4224576145cSOleg Nesterov 4237ed20e1aSJesper Juhl if (!valid_signal(data)) 4241da177e4SLinus Torvalds return -EIO; 4251da177e4SLinus Torvalds 4261da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 4271da177e4SLinus Torvalds ptrace_disable(child); 4287d941432SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 4291da177e4SLinus Torvalds 43095c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 43139c626aeSOleg Nesterov /* 43239c626aeSOleg Nesterov * This child can be already killed. Make sure de_thread() or 43339c626aeSOleg Nesterov * our sub-thread doing do_wait() didn't do release_task() yet. 43439c626aeSOleg Nesterov */ 43595c3eb76SOleg Nesterov if (child->ptrace) { 43695c3eb76SOleg Nesterov child->exit_code = data; 4374576145cSOleg Nesterov dead = __ptrace_detach(current, child); 43895c3eb76SOleg Nesterov } 4391da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 4401da177e4SLinus Torvalds 441f701e5b7SVladimir Zapolskiy proc_ptrace_connector(child, PTRACE_DETACH); 4424576145cSOleg Nesterov if (unlikely(dead)) 4434576145cSOleg Nesterov release_task(child); 4444576145cSOleg Nesterov 4451da177e4SLinus Torvalds return 0; 4461da177e4SLinus Torvalds } 4471da177e4SLinus Torvalds 44839c626aeSOleg Nesterov /* 449c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 450c7e49c14SOleg Nesterov * for writing, and returns with it held too. But note it can release 451c7e49c14SOleg Nesterov * and reacquire the lock. 45239c626aeSOleg Nesterov */ 45339c626aeSOleg Nesterov void exit_ptrace(struct task_struct *tracer) 454c4b5ed25SNamhyung Kim __releases(&tasklist_lock) 455c4b5ed25SNamhyung Kim __acquires(&tasklist_lock) 45639c626aeSOleg Nesterov { 45739c626aeSOleg Nesterov struct task_struct *p, *n; 45839c626aeSOleg Nesterov LIST_HEAD(ptrace_dead); 45939c626aeSOleg Nesterov 460c7e49c14SOleg Nesterov if (likely(list_empty(&tracer->ptraced))) 461c7e49c14SOleg Nesterov return; 462c7e49c14SOleg Nesterov 46339c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 46439c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 46539c626aeSOleg Nesterov list_add(&p->ptrace_entry, &ptrace_dead); 46639c626aeSOleg Nesterov } 46739c626aeSOleg Nesterov 468c7e49c14SOleg Nesterov write_unlock_irq(&tasklist_lock); 46939c626aeSOleg Nesterov BUG_ON(!list_empty(&tracer->ptraced)); 47039c626aeSOleg Nesterov 47139c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { 47239c626aeSOleg Nesterov list_del_init(&p->ptrace_entry); 47339c626aeSOleg Nesterov release_task(p); 47439c626aeSOleg Nesterov } 475c7e49c14SOleg Nesterov 476c7e49c14SOleg Nesterov write_lock_irq(&tasklist_lock); 47739c626aeSOleg Nesterov } 47839c626aeSOleg Nesterov 4791da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 4801da177e4SLinus Torvalds { 4811da177e4SLinus Torvalds int copied = 0; 4821da177e4SLinus Torvalds 4831da177e4SLinus Torvalds while (len > 0) { 4841da177e4SLinus Torvalds char buf[128]; 4851da177e4SLinus Torvalds int this_len, retval; 4861da177e4SLinus Torvalds 4871da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4881da177e4SLinus Torvalds retval = access_process_vm(tsk, src, buf, this_len, 0); 4891da177e4SLinus Torvalds if (!retval) { 4901da177e4SLinus Torvalds if (copied) 4911da177e4SLinus Torvalds break; 4921da177e4SLinus Torvalds return -EIO; 4931da177e4SLinus Torvalds } 4941da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 4951da177e4SLinus Torvalds return -EFAULT; 4961da177e4SLinus Torvalds copied += retval; 4971da177e4SLinus Torvalds src += retval; 4981da177e4SLinus Torvalds dst += retval; 4991da177e4SLinus Torvalds len -= retval; 5001da177e4SLinus Torvalds } 5011da177e4SLinus Torvalds return copied; 5021da177e4SLinus Torvalds } 5031da177e4SLinus Torvalds 5041da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 5051da177e4SLinus Torvalds { 5061da177e4SLinus Torvalds int copied = 0; 5071da177e4SLinus Torvalds 5081da177e4SLinus Torvalds while (len > 0) { 5091da177e4SLinus Torvalds char buf[128]; 5101da177e4SLinus Torvalds int this_len, retval; 5111da177e4SLinus Torvalds 5121da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 5131da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 5141da177e4SLinus Torvalds return -EFAULT; 5151da177e4SLinus Torvalds retval = access_process_vm(tsk, dst, buf, this_len, 1); 5161da177e4SLinus Torvalds if (!retval) { 5171da177e4SLinus Torvalds if (copied) 5181da177e4SLinus Torvalds break; 5191da177e4SLinus Torvalds return -EIO; 5201da177e4SLinus Torvalds } 5211da177e4SLinus Torvalds copied += retval; 5221da177e4SLinus Torvalds src += retval; 5231da177e4SLinus Torvalds dst += retval; 5241da177e4SLinus Torvalds len -= retval; 5251da177e4SLinus Torvalds } 5261da177e4SLinus Torvalds return copied; 5271da177e4SLinus Torvalds } 5281da177e4SLinus Torvalds 5294abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 5301da177e4SLinus Torvalds { 5318c5cf9e5SDenys Vlasenko if (data & ~(unsigned long)PTRACE_O_MASK) 5328c5cf9e5SDenys Vlasenko return -EINVAL; 5338c5cf9e5SDenys Vlasenko 5341da177e4SLinus Torvalds child->ptrace &= ~PT_TRACE_MASK; 5351da177e4SLinus Torvalds 5361da177e4SLinus Torvalds if (data & PTRACE_O_TRACESYSGOOD) 5371da177e4SLinus Torvalds child->ptrace |= PT_TRACESYSGOOD; 5381da177e4SLinus Torvalds 5391da177e4SLinus Torvalds if (data & PTRACE_O_TRACEFORK) 5401da177e4SLinus Torvalds child->ptrace |= PT_TRACE_FORK; 5411da177e4SLinus Torvalds 5421da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORK) 5431da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK; 5441da177e4SLinus Torvalds 5451da177e4SLinus Torvalds if (data & PTRACE_O_TRACECLONE) 5461da177e4SLinus Torvalds child->ptrace |= PT_TRACE_CLONE; 5471da177e4SLinus Torvalds 5481da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXEC) 5491da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXEC; 5501da177e4SLinus Torvalds 5511da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORKDONE) 5521da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK_DONE; 5531da177e4SLinus Torvalds 5541da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXIT) 5551da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXIT; 5561da177e4SLinus Torvalds 5578c5cf9e5SDenys Vlasenko return 0; 5581da177e4SLinus Torvalds } 5591da177e4SLinus Torvalds 560e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 5611da177e4SLinus Torvalds { 562e4961254SOleg Nesterov unsigned long flags; 5631da177e4SLinus Torvalds int error = -ESRCH; 5641da177e4SLinus Torvalds 565e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5661da177e4SLinus Torvalds error = -EINVAL; 5671da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 568e16b2781SRoland McGrath *info = *child->last_siginfo; 5691da177e4SLinus Torvalds error = 0; 5701da177e4SLinus Torvalds } 571e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5721da177e4SLinus Torvalds } 5731da177e4SLinus Torvalds return error; 5741da177e4SLinus Torvalds } 5751da177e4SLinus Torvalds 576e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 5771da177e4SLinus Torvalds { 578e4961254SOleg Nesterov unsigned long flags; 5791da177e4SLinus Torvalds int error = -ESRCH; 5801da177e4SLinus Torvalds 581e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5821da177e4SLinus Torvalds error = -EINVAL; 5831da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 584e16b2781SRoland McGrath *child->last_siginfo = *info; 5851da177e4SLinus Torvalds error = 0; 5861da177e4SLinus Torvalds } 587e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5881da177e4SLinus Torvalds } 5891da177e4SLinus Torvalds return error; 5901da177e4SLinus Torvalds } 5911da177e4SLinus Torvalds 59236df29d7SRoland McGrath 59336df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 59436df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 59536df29d7SRoland McGrath #else 59636df29d7SRoland McGrath #define is_singlestep(request) 0 59736df29d7SRoland McGrath #endif 59836df29d7SRoland McGrath 5995b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 6005b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 6015b88abbfSRoland McGrath #else 6025b88abbfSRoland McGrath #define is_singleblock(request) 0 6035b88abbfSRoland McGrath #endif 6045b88abbfSRoland McGrath 60536df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 60636df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 60736df29d7SRoland McGrath #else 60836df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 60936df29d7SRoland McGrath #endif 61036df29d7SRoland McGrath 6114abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 6124abf9869SNamhyung Kim unsigned long data) 61336df29d7SRoland McGrath { 61436df29d7SRoland McGrath if (!valid_signal(data)) 61536df29d7SRoland McGrath return -EIO; 61636df29d7SRoland McGrath 61736df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 61836df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 61936df29d7SRoland McGrath else 62036df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 62136df29d7SRoland McGrath 62236df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 62336df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 62436df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 62536df29d7SRoland McGrath else 62636df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 62736df29d7SRoland McGrath #endif 62836df29d7SRoland McGrath 6295b88abbfSRoland McGrath if (is_singleblock(request)) { 6305b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 6315b88abbfSRoland McGrath return -EIO; 6325b88abbfSRoland McGrath user_enable_block_step(child); 6335b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 63436df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 63536df29d7SRoland McGrath return -EIO; 63636df29d7SRoland McGrath user_enable_single_step(child); 6373a709703SRoland McGrath } else { 63836df29d7SRoland McGrath user_disable_single_step(child); 6393a709703SRoland McGrath } 64036df29d7SRoland McGrath 64136df29d7SRoland McGrath child->exit_code = data; 6420666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 64336df29d7SRoland McGrath 64436df29d7SRoland McGrath return 0; 64536df29d7SRoland McGrath } 64636df29d7SRoland McGrath 6472225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 6482225a122SSuresh Siddha 6492225a122SSuresh Siddha static const struct user_regset * 6502225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 6512225a122SSuresh Siddha { 6522225a122SSuresh Siddha const struct user_regset *regset; 6532225a122SSuresh Siddha int n; 6542225a122SSuresh Siddha 6552225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 6562225a122SSuresh Siddha regset = view->regsets + n; 6572225a122SSuresh Siddha if (regset->core_note_type == type) 6582225a122SSuresh Siddha return regset; 6592225a122SSuresh Siddha } 6602225a122SSuresh Siddha 6612225a122SSuresh Siddha return NULL; 6622225a122SSuresh Siddha } 6632225a122SSuresh Siddha 6642225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 6652225a122SSuresh Siddha struct iovec *kiov) 6662225a122SSuresh Siddha { 6672225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 6682225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 6692225a122SSuresh Siddha int regset_no; 6702225a122SSuresh Siddha 6712225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 672c6a0dd7eSSuresh Siddha return -EINVAL; 6732225a122SSuresh Siddha 6742225a122SSuresh Siddha regset_no = regset - view->regsets; 6752225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 6762225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 6772225a122SSuresh Siddha 6782225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 6792225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 6802225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6812225a122SSuresh Siddha else 6822225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 6832225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6842225a122SSuresh Siddha } 6852225a122SSuresh Siddha 6862225a122SSuresh Siddha #endif 6872225a122SSuresh Siddha 6881da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 6894abf9869SNamhyung Kim unsigned long addr, unsigned long data) 6901da177e4SLinus Torvalds { 691fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 6921da177e4SLinus Torvalds int ret = -EIO; 693544b2c91STejun Heo siginfo_t siginfo, *si; 6949fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 6959fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 696fca26f26STejun Heo unsigned long flags; 6971da177e4SLinus Torvalds 6981da177e4SLinus Torvalds switch (request) { 69916c3e389SRoland McGrath case PTRACE_PEEKTEXT: 70016c3e389SRoland McGrath case PTRACE_PEEKDATA: 70116c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 70216c3e389SRoland McGrath case PTRACE_POKETEXT: 70316c3e389SRoland McGrath case PTRACE_POKEDATA: 70416c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 70516c3e389SRoland McGrath 7061da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 7071da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 7081da177e4SLinus Torvalds #endif 7091da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 7101da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 7111da177e4SLinus Torvalds break; 7121da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 7139fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 7141da177e4SLinus Torvalds break; 715e16b2781SRoland McGrath 7161da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 717e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 718e16b2781SRoland McGrath if (!ret) 7199fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 7201da177e4SLinus Torvalds break; 721e16b2781SRoland McGrath 7221da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 7239fed81dcSNamhyung Kim if (copy_from_user(&siginfo, datavp, sizeof siginfo)) 724e16b2781SRoland McGrath ret = -EFAULT; 725e16b2781SRoland McGrath else 726e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 7271da177e4SLinus Torvalds break; 728e16b2781SRoland McGrath 729fca26f26STejun Heo case PTRACE_INTERRUPT: 730fca26f26STejun Heo /* 731fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 732fca26f26STejun Heo * control. At least one trap is guaranteed to happen 733fca26f26STejun Heo * after this request. If @child is already trapped, the 734fca26f26STejun Heo * current trap is not disturbed and another trap will 735fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 736fca26f26STejun Heo * 737fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 738fca26f26STejun Heo * the pending condition is cleared regardless. 739fca26f26STejun Heo */ 740fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 741fca26f26STejun Heo break; 742fca26f26STejun Heo 743544b2c91STejun Heo /* 744544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 745544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 746544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 747544b2c91STejun Heo * tracee into STOP. 748544b2c91STejun Heo */ 749fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 750544b2c91STejun Heo signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 751544b2c91STejun Heo 752544b2c91STejun Heo unlock_task_sighand(child, &flags); 753544b2c91STejun Heo ret = 0; 754544b2c91STejun Heo break; 755544b2c91STejun Heo 756544b2c91STejun Heo case PTRACE_LISTEN: 757544b2c91STejun Heo /* 758544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 759544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 760544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 761544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 762544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 763544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 764544b2c91STejun Heo */ 765544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 766544b2c91STejun Heo break; 767544b2c91STejun Heo 768544b2c91STejun Heo si = child->last_siginfo; 769f9d81f61SOleg Nesterov if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { 770544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 771544b2c91STejun Heo /* 772f9d81f61SOleg Nesterov * If NOTIFY is set, it means event happened between 773f9d81f61SOleg Nesterov * start of this trap and now. Trigger re-trap. 774544b2c91STejun Heo */ 775544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 776544b2c91STejun Heo signal_wake_up(child, true); 777fca26f26STejun Heo ret = 0; 778f9d81f61SOleg Nesterov } 779f9d81f61SOleg Nesterov unlock_task_sighand(child, &flags); 780fca26f26STejun Heo break; 781fca26f26STejun Heo 7821bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 7831bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 7841bcf5482SAlexey Dobriyan break; 78536df29d7SRoland McGrath 7869c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 7879c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 788e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 7899c1a1259SMike Frysinger unsigned long tmp = 0; 7909c1a1259SMike Frysinger 791e0129ef9SOleg Nesterov ret = -ESRCH; 792e0129ef9SOleg Nesterov if (!mm) 793e0129ef9SOleg Nesterov break; 794e0129ef9SOleg Nesterov 7959c1a1259SMike Frysinger switch (addr) { 7969c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 797e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 7989c1a1259SMike Frysinger break; 7999c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 800e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 8019c1a1259SMike Frysinger break; 8029c1a1259SMike Frysinger default: 8039c1a1259SMike Frysinger break; 8049c1a1259SMike Frysinger } 805e0129ef9SOleg Nesterov mmput(mm); 8069c1a1259SMike Frysinger 8079fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 8089c1a1259SMike Frysinger break; 8099c1a1259SMike Frysinger } 8109c1a1259SMike Frysinger #endif 8119c1a1259SMike Frysinger 81236df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 81336df29d7SRoland McGrath case PTRACE_SINGLESTEP: 81436df29d7SRoland McGrath #endif 8155b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 8165b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 8175b88abbfSRoland McGrath #endif 81836df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 81936df29d7SRoland McGrath case PTRACE_SYSEMU: 82036df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 82136df29d7SRoland McGrath #endif 82236df29d7SRoland McGrath case PTRACE_SYSCALL: 82336df29d7SRoland McGrath case PTRACE_CONT: 82436df29d7SRoland McGrath return ptrace_resume(child, request, data); 82536df29d7SRoland McGrath 82636df29d7SRoland McGrath case PTRACE_KILL: 82736df29d7SRoland McGrath if (child->exit_state) /* already dead */ 82836df29d7SRoland McGrath return 0; 82936df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 83036df29d7SRoland McGrath 8312225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8322225a122SSuresh Siddha case PTRACE_GETREGSET: 8332225a122SSuresh Siddha case PTRACE_SETREGSET: 8342225a122SSuresh Siddha { 8352225a122SSuresh Siddha struct iovec kiov; 8369fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 8372225a122SSuresh Siddha 8382225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 8392225a122SSuresh Siddha return -EFAULT; 8402225a122SSuresh Siddha 8412225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 8422225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 8432225a122SSuresh Siddha return -EFAULT; 8442225a122SSuresh Siddha 8452225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 8462225a122SSuresh Siddha if (!ret) 8472225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 8482225a122SSuresh Siddha break; 8492225a122SSuresh Siddha } 8502225a122SSuresh Siddha #endif 8511da177e4SLinus Torvalds default: 8521da177e4SLinus Torvalds break; 8531da177e4SLinus Torvalds } 8541da177e4SLinus Torvalds 8551da177e4SLinus Torvalds return ret; 8561da177e4SLinus Torvalds } 857481bed45SChristoph Hellwig 8588053bdd5SOleg Nesterov static struct task_struct *ptrace_get_task_struct(pid_t pid) 8596b9c7ed8SChristoph Hellwig { 8606b9c7ed8SChristoph Hellwig struct task_struct *child; 8616b9c7ed8SChristoph Hellwig 8628053bdd5SOleg Nesterov rcu_read_lock(); 863228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 864481bed45SChristoph Hellwig if (child) 865481bed45SChristoph Hellwig get_task_struct(child); 8668053bdd5SOleg Nesterov rcu_read_unlock(); 867f400e198SSukadev Bhattiprolu 868481bed45SChristoph Hellwig if (!child) 8696b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 8706b9c7ed8SChristoph Hellwig return child; 871481bed45SChristoph Hellwig } 872481bed45SChristoph Hellwig 8730ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 8740ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 8750ac15559SChristoph Hellwig #endif 8760ac15559SChristoph Hellwig 8774abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 8784abf9869SNamhyung Kim unsigned long, data) 879481bed45SChristoph Hellwig { 880481bed45SChristoph Hellwig struct task_struct *child; 881481bed45SChristoph Hellwig long ret; 882481bed45SChristoph Hellwig 8836b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 8846b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 8856ea6dd93SHaavard Skinnemoen if (!ret) 8866ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 887481bed45SChristoph Hellwig goto out; 8886b9c7ed8SChristoph Hellwig } 8896b9c7ed8SChristoph Hellwig 8906b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 8916b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 8926b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 8936b9c7ed8SChristoph Hellwig goto out; 8946b9c7ed8SChristoph Hellwig } 895481bed45SChristoph Hellwig 8963544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 8973544d72aSTejun Heo ret = ptrace_attach(child, request, data); 8980ac15559SChristoph Hellwig /* 8990ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 9000ac15559SChristoph Hellwig * a ptrace attach. 9010ac15559SChristoph Hellwig */ 9020ac15559SChristoph Hellwig if (!ret) 9030ac15559SChristoph Hellwig arch_ptrace_attach(child); 904005f18dfSChristoph Hellwig goto out_put_task_struct; 905481bed45SChristoph Hellwig } 906481bed45SChristoph Hellwig 907fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 908fca26f26STejun Heo request == PTRACE_INTERRUPT); 909481bed45SChristoph Hellwig if (ret < 0) 910481bed45SChristoph Hellwig goto out_put_task_struct; 911481bed45SChristoph Hellwig 912481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 913481bed45SChristoph Hellwig 914481bed45SChristoph Hellwig out_put_task_struct: 915481bed45SChristoph Hellwig put_task_struct(child); 916481bed45SChristoph Hellwig out: 917481bed45SChristoph Hellwig return ret; 918481bed45SChristoph Hellwig } 91976647323SAlexey Dobriyan 9204abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 9214abf9869SNamhyung Kim unsigned long data) 92276647323SAlexey Dobriyan { 92376647323SAlexey Dobriyan unsigned long tmp; 92476647323SAlexey Dobriyan int copied; 92576647323SAlexey Dobriyan 92676647323SAlexey Dobriyan copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); 92776647323SAlexey Dobriyan if (copied != sizeof(tmp)) 92876647323SAlexey Dobriyan return -EIO; 92976647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 93076647323SAlexey Dobriyan } 931f284ce72SAlexey Dobriyan 9324abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 9334abf9869SNamhyung Kim unsigned long data) 934f284ce72SAlexey Dobriyan { 935f284ce72SAlexey Dobriyan int copied; 936f284ce72SAlexey Dobriyan 937f284ce72SAlexey Dobriyan copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); 938f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 939f284ce72SAlexey Dobriyan } 940032d82d9SRoland McGrath 94196b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 942032d82d9SRoland McGrath #include <linux/compat.h> 943032d82d9SRoland McGrath 944032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 945032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 946032d82d9SRoland McGrath { 947032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 948032d82d9SRoland McGrath compat_ulong_t word; 949e16b2781SRoland McGrath siginfo_t siginfo; 950032d82d9SRoland McGrath int ret; 951032d82d9SRoland McGrath 952032d82d9SRoland McGrath switch (request) { 953032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 954032d82d9SRoland McGrath case PTRACE_PEEKDATA: 955032d82d9SRoland McGrath ret = access_process_vm(child, addr, &word, sizeof(word), 0); 956032d82d9SRoland McGrath if (ret != sizeof(word)) 957032d82d9SRoland McGrath ret = -EIO; 958032d82d9SRoland McGrath else 959032d82d9SRoland McGrath ret = put_user(word, datap); 960032d82d9SRoland McGrath break; 961032d82d9SRoland McGrath 962032d82d9SRoland McGrath case PTRACE_POKETEXT: 963032d82d9SRoland McGrath case PTRACE_POKEDATA: 964032d82d9SRoland McGrath ret = access_process_vm(child, addr, &data, sizeof(data), 1); 965032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 966032d82d9SRoland McGrath break; 967032d82d9SRoland McGrath 968032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 969032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 970032d82d9SRoland McGrath break; 971032d82d9SRoland McGrath 972e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 973e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 974e16b2781SRoland McGrath if (!ret) 975e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 976e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 977e16b2781SRoland McGrath &siginfo); 978e16b2781SRoland McGrath break; 979e16b2781SRoland McGrath 980e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 981e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 982e16b2781SRoland McGrath if (copy_siginfo_from_user32( 983e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 984e16b2781SRoland McGrath ret = -EFAULT; 985e16b2781SRoland McGrath else 986e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 987e16b2781SRoland McGrath break; 9882225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 9892225a122SSuresh Siddha case PTRACE_GETREGSET: 9902225a122SSuresh Siddha case PTRACE_SETREGSET: 9912225a122SSuresh Siddha { 9922225a122SSuresh Siddha struct iovec kiov; 9932225a122SSuresh Siddha struct compat_iovec __user *uiov = 9942225a122SSuresh Siddha (struct compat_iovec __user *) datap; 9952225a122SSuresh Siddha compat_uptr_t ptr; 9962225a122SSuresh Siddha compat_size_t len; 9972225a122SSuresh Siddha 9982225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 9992225a122SSuresh Siddha return -EFAULT; 10002225a122SSuresh Siddha 10012225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 10022225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 10032225a122SSuresh Siddha return -EFAULT; 10042225a122SSuresh Siddha 10052225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 10062225a122SSuresh Siddha kiov.iov_len = len; 10072225a122SSuresh Siddha 10082225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 10092225a122SSuresh Siddha if (!ret) 10102225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 10112225a122SSuresh Siddha break; 10122225a122SSuresh Siddha } 10132225a122SSuresh Siddha #endif 1014e16b2781SRoland McGrath 1015032d82d9SRoland McGrath default: 1016032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 1017032d82d9SRoland McGrath } 1018032d82d9SRoland McGrath 1019032d82d9SRoland McGrath return ret; 1020032d82d9SRoland McGrath } 1021c269f196SRoland McGrath 1022c269f196SRoland McGrath asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, 1023c269f196SRoland McGrath compat_long_t addr, compat_long_t data) 1024c269f196SRoland McGrath { 1025c269f196SRoland McGrath struct task_struct *child; 1026c269f196SRoland McGrath long ret; 1027c269f196SRoland McGrath 1028c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1029c269f196SRoland McGrath ret = ptrace_traceme(); 1030c269f196SRoland McGrath goto out; 1031c269f196SRoland McGrath } 1032c269f196SRoland McGrath 1033c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 1034c269f196SRoland McGrath if (IS_ERR(child)) { 1035c269f196SRoland McGrath ret = PTR_ERR(child); 1036c269f196SRoland McGrath goto out; 1037c269f196SRoland McGrath } 1038c269f196SRoland McGrath 10393544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 10403544d72aSTejun Heo ret = ptrace_attach(child, request, data); 1041c269f196SRoland McGrath /* 1042c269f196SRoland McGrath * Some architectures need to do book-keeping after 1043c269f196SRoland McGrath * a ptrace attach. 1044c269f196SRoland McGrath */ 1045c269f196SRoland McGrath if (!ret) 1046c269f196SRoland McGrath arch_ptrace_attach(child); 1047c269f196SRoland McGrath goto out_put_task_struct; 1048c269f196SRoland McGrath } 1049c269f196SRoland McGrath 1050fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1051fca26f26STejun Heo request == PTRACE_INTERRUPT); 1052c269f196SRoland McGrath if (!ret) 1053c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 1054c269f196SRoland McGrath 1055c269f196SRoland McGrath out_put_task_struct: 1056c269f196SRoland McGrath put_task_struct(child); 1057c269f196SRoland McGrath out: 1058c269f196SRoland McGrath return ret; 1059c269f196SRoland McGrath } 106096b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1061bf26c018SFrederic Weisbecker 1062bf26c018SFrederic Weisbecker #ifdef CONFIG_HAVE_HW_BREAKPOINT 1063bf26c018SFrederic Weisbecker int ptrace_get_breakpoints(struct task_struct *tsk) 1064bf26c018SFrederic Weisbecker { 1065bf26c018SFrederic Weisbecker if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) 1066bf26c018SFrederic Weisbecker return 0; 1067bf26c018SFrederic Weisbecker 1068bf26c018SFrederic Weisbecker return -1; 1069bf26c018SFrederic Weisbecker } 1070bf26c018SFrederic Weisbecker 1071bf26c018SFrederic Weisbecker void ptrace_put_breakpoints(struct task_struct *tsk) 1072bf26c018SFrederic Weisbecker { 1073bf26c018SFrederic Weisbecker if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) 1074bf26c018SFrederic Weisbecker flush_ptrace_hw_breakpoint(tsk); 1075bf26c018SFrederic Weisbecker } 1076bf26c018SFrederic Weisbecker #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 1077