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); 201c4a4d603SEric W. Biederman if (cred->user_ns == tcred->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; 209c4a4d603SEric W. Biederman if (ptrace_has_cap(tcred->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, 234aa9147c9SDenys Vlasenko unsigned long addr, 2353544d72aSTejun Heo unsigned long flags) 2361da177e4SLinus Torvalds { 2373544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 2381da177e4SLinus Torvalds int retval; 239f5b40e36SLinus Torvalds 2403544d72aSTejun Heo retval = -EIO; 241aa9147c9SDenys Vlasenko if (seize) { 242aa9147c9SDenys Vlasenko if (addr != 0) 2433544d72aSTejun Heo goto out; 244aa9147c9SDenys Vlasenko if (flags & ~(unsigned long)PTRACE_O_MASK) 245aa9147c9SDenys Vlasenko goto out; 246aa9147c9SDenys Vlasenko flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); 247aa9147c9SDenys Vlasenko } else { 248aa9147c9SDenys Vlasenko flags = PT_PTRACED; 249aa9147c9SDenys Vlasenko } 2503544d72aSTejun Heo 251a5cb013dSAl Viro audit_ptrace(task); 252a5cb013dSAl Viro 2531da177e4SLinus Torvalds retval = -EPERM; 254b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 255b79b7ba9SOleg Nesterov goto out; 256bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 257f5b40e36SLinus Torvalds goto out; 258f5b40e36SLinus Torvalds 259f2f0b00aSOleg Nesterov /* 260f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 26186b6c1f3SDenys Vlasenko * SUID, SGID and LSM creds get determined differently 2625e751e99SDavid Howells * under ptrace. 263d84f4f99SDavid Howells */ 264793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 2659b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 266d84f4f99SDavid Howells goto out; 2674b105cbbSOleg Nesterov 268f5b40e36SLinus Torvalds task_lock(task); 269006ebb40SStephen Smalley retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); 2704b105cbbSOleg Nesterov task_unlock(task); 2711da177e4SLinus Torvalds if (retval) 2724b105cbbSOleg Nesterov goto unlock_creds; 2731da177e4SLinus Torvalds 2744b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 275b79b7ba9SOleg Nesterov retval = -EPERM; 276b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 2774b105cbbSOleg Nesterov goto unlock_tasklist; 278f2f0b00aSOleg Nesterov if (task->ptrace) 2794b105cbbSOleg Nesterov goto unlock_tasklist; 280b79b7ba9SOleg Nesterov 2813544d72aSTejun Heo if (seize) 282aa9147c9SDenys Vlasenko flags |= PT_SEIZED; 283f1c84daeSEric Paris if (ns_capable(task_user_ns(task), CAP_SYS_PTRACE)) 284aa9147c9SDenys Vlasenko flags |= PT_PTRACE_CAP; 285aa9147c9SDenys Vlasenko task->ptrace = flags; 2861da177e4SLinus Torvalds 2871da177e4SLinus Torvalds __ptrace_link(task, current); 2883544d72aSTejun Heo 2893544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 2903544d72aSTejun Heo if (!seize) 29133e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 292b79b7ba9SOleg Nesterov 293d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 294d79fdd6dSTejun Heo 295d79fdd6dSTejun Heo /* 29673ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 297d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 298d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 299d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 300d79fdd6dSTejun Heo * for the transition to complete before returning from this 301d79fdd6dSTejun Heo * function. 302d79fdd6dSTejun Heo * 303d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 304d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 305d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 306d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 307d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 308d79fdd6dSTejun Heo * 309d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 310d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 311d79fdd6dSTejun Heo */ 3127dd3db54STejun Heo if (task_is_stopped(task) && 31373ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 314d79fdd6dSTejun Heo signal_wake_up(task, 1); 315d79fdd6dSTejun Heo 316d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 317d79fdd6dSTejun Heo 318b79b7ba9SOleg Nesterov retval = 0; 3194b105cbbSOleg Nesterov unlock_tasklist: 3204b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3214b105cbbSOleg Nesterov unlock_creds: 3229b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 323f5b40e36SLinus Torvalds out: 324f701e5b7SVladimir Zapolskiy if (!retval) { 32562c124ffSTejun Heo wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, 32662c124ffSTejun Heo ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE); 327f701e5b7SVladimir Zapolskiy proc_ptrace_connector(task, PTRACE_ATTACH); 328f701e5b7SVladimir Zapolskiy } 329f701e5b7SVladimir Zapolskiy 3301da177e4SLinus Torvalds return retval; 3311da177e4SLinus Torvalds } 3321da177e4SLinus Torvalds 333f2f0b00aSOleg Nesterov /** 334f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 335f2f0b00aSOleg Nesterov * 336f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 337f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 338f2f0b00aSOleg Nesterov */ 339e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 340f2f0b00aSOleg Nesterov { 341f2f0b00aSOleg Nesterov int ret = -EPERM; 342f2f0b00aSOleg Nesterov 3434b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 3444b105cbbSOleg Nesterov /* Are we already being traced? */ 345f2f0b00aSOleg Nesterov if (!current->ptrace) { 346f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 347f2f0b00aSOleg Nesterov /* 348f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 349f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 350f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 351f2f0b00aSOleg Nesterov */ 352f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 353f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 354f2f0b00aSOleg Nesterov __ptrace_link(current, current->real_parent); 355f2f0b00aSOleg Nesterov } 356f2f0b00aSOleg Nesterov } 3574b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3584b105cbbSOleg Nesterov 359f2f0b00aSOleg Nesterov return ret; 360f2f0b00aSOleg Nesterov } 361f2f0b00aSOleg Nesterov 36239c626aeSOleg Nesterov /* 36339c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 36439c626aeSOleg Nesterov */ 36539c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 36639c626aeSOleg Nesterov { 36739c626aeSOleg Nesterov int ret; 36839c626aeSOleg Nesterov spin_lock(&sigh->siglock); 36939c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 37039c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 37139c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 37239c626aeSOleg Nesterov return ret; 37339c626aeSOleg Nesterov } 37439c626aeSOleg Nesterov 37539c626aeSOleg Nesterov /* 37639c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 37739c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 37839c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 37939c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 38039c626aeSOleg Nesterov * 38139c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 38239c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 38339c626aeSOleg Nesterov * If it should reap itself, return true. 38439c626aeSOleg Nesterov * 385a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 386a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 387a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 388a7f0765eSOleg Nesterov * do_wait(). 38939c626aeSOleg Nesterov */ 39039c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 39139c626aeSOleg Nesterov { 3929843a1e9SOleg Nesterov bool dead; 3939843a1e9SOleg Nesterov 39439c626aeSOleg Nesterov __ptrace_unlink(p); 39539c626aeSOleg Nesterov 3969843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 3979843a1e9SOleg Nesterov return false; 3989843a1e9SOleg Nesterov 3999843a1e9SOleg Nesterov dead = !thread_group_leader(p); 4009843a1e9SOleg Nesterov 4019843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 40239c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 4039843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 404a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 405a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 4069843a1e9SOleg Nesterov dead = true; 40739c626aeSOleg Nesterov } 408a7f0765eSOleg Nesterov } 40939c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 4109843a1e9SOleg Nesterov if (dead) 41139c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 4129843a1e9SOleg Nesterov return dead; 41339c626aeSOleg Nesterov } 41439c626aeSOleg Nesterov 415e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 4161da177e4SLinus Torvalds { 41739c626aeSOleg Nesterov bool dead = false; 4184576145cSOleg Nesterov 4197ed20e1aSJesper Juhl if (!valid_signal(data)) 4201da177e4SLinus Torvalds return -EIO; 4211da177e4SLinus Torvalds 4221da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 4231da177e4SLinus Torvalds ptrace_disable(child); 4247d941432SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 4251da177e4SLinus Torvalds 42695c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 42739c626aeSOleg Nesterov /* 42839c626aeSOleg Nesterov * This child can be already killed. Make sure de_thread() or 42939c626aeSOleg Nesterov * our sub-thread doing do_wait() didn't do release_task() yet. 43039c626aeSOleg Nesterov */ 43195c3eb76SOleg Nesterov if (child->ptrace) { 43295c3eb76SOleg Nesterov child->exit_code = data; 4334576145cSOleg Nesterov dead = __ptrace_detach(current, child); 43495c3eb76SOleg Nesterov } 4351da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 4361da177e4SLinus Torvalds 437f701e5b7SVladimir Zapolskiy proc_ptrace_connector(child, PTRACE_DETACH); 4384576145cSOleg Nesterov if (unlikely(dead)) 4394576145cSOleg Nesterov release_task(child); 4404576145cSOleg Nesterov 4411da177e4SLinus Torvalds return 0; 4421da177e4SLinus Torvalds } 4431da177e4SLinus Torvalds 44439c626aeSOleg Nesterov /* 445c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 446c7e49c14SOleg Nesterov * for writing, and returns with it held too. But note it can release 447c7e49c14SOleg Nesterov * and reacquire the lock. 44839c626aeSOleg Nesterov */ 44939c626aeSOleg Nesterov void exit_ptrace(struct task_struct *tracer) 450c4b5ed25SNamhyung Kim __releases(&tasklist_lock) 451c4b5ed25SNamhyung Kim __acquires(&tasklist_lock) 45239c626aeSOleg Nesterov { 45339c626aeSOleg Nesterov struct task_struct *p, *n; 45439c626aeSOleg Nesterov LIST_HEAD(ptrace_dead); 45539c626aeSOleg Nesterov 456c7e49c14SOleg Nesterov if (likely(list_empty(&tracer->ptraced))) 457c7e49c14SOleg Nesterov return; 458c7e49c14SOleg Nesterov 45939c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 46039c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 46139c626aeSOleg Nesterov list_add(&p->ptrace_entry, &ptrace_dead); 46239c626aeSOleg Nesterov } 46339c626aeSOleg Nesterov 464c7e49c14SOleg Nesterov write_unlock_irq(&tasklist_lock); 46539c626aeSOleg Nesterov BUG_ON(!list_empty(&tracer->ptraced)); 46639c626aeSOleg Nesterov 46739c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { 46839c626aeSOleg Nesterov list_del_init(&p->ptrace_entry); 46939c626aeSOleg Nesterov release_task(p); 47039c626aeSOleg Nesterov } 471c7e49c14SOleg Nesterov 472c7e49c14SOleg Nesterov write_lock_irq(&tasklist_lock); 47339c626aeSOleg Nesterov } 47439c626aeSOleg Nesterov 4751da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 4761da177e4SLinus Torvalds { 4771da177e4SLinus Torvalds int copied = 0; 4781da177e4SLinus Torvalds 4791da177e4SLinus Torvalds while (len > 0) { 4801da177e4SLinus Torvalds char buf[128]; 4811da177e4SLinus Torvalds int this_len, retval; 4821da177e4SLinus Torvalds 4831da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4841da177e4SLinus Torvalds retval = access_process_vm(tsk, src, buf, this_len, 0); 4851da177e4SLinus Torvalds if (!retval) { 4861da177e4SLinus Torvalds if (copied) 4871da177e4SLinus Torvalds break; 4881da177e4SLinus Torvalds return -EIO; 4891da177e4SLinus Torvalds } 4901da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 4911da177e4SLinus Torvalds return -EFAULT; 4921da177e4SLinus Torvalds copied += retval; 4931da177e4SLinus Torvalds src += retval; 4941da177e4SLinus Torvalds dst += retval; 4951da177e4SLinus Torvalds len -= retval; 4961da177e4SLinus Torvalds } 4971da177e4SLinus Torvalds return copied; 4981da177e4SLinus Torvalds } 4991da177e4SLinus Torvalds 5001da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 5011da177e4SLinus Torvalds { 5021da177e4SLinus Torvalds int copied = 0; 5031da177e4SLinus Torvalds 5041da177e4SLinus Torvalds while (len > 0) { 5051da177e4SLinus Torvalds char buf[128]; 5061da177e4SLinus Torvalds int this_len, retval; 5071da177e4SLinus Torvalds 5081da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 5091da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 5101da177e4SLinus Torvalds return -EFAULT; 5111da177e4SLinus Torvalds retval = access_process_vm(tsk, dst, buf, this_len, 1); 5121da177e4SLinus Torvalds if (!retval) { 5131da177e4SLinus Torvalds if (copied) 5141da177e4SLinus Torvalds break; 5151da177e4SLinus Torvalds return -EIO; 5161da177e4SLinus Torvalds } 5171da177e4SLinus Torvalds copied += retval; 5181da177e4SLinus Torvalds src += retval; 5191da177e4SLinus Torvalds dst += retval; 5201da177e4SLinus Torvalds len -= retval; 5211da177e4SLinus Torvalds } 5221da177e4SLinus Torvalds return copied; 5231da177e4SLinus Torvalds } 5241da177e4SLinus Torvalds 5254abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 5261da177e4SLinus Torvalds { 52786b6c1f3SDenys Vlasenko unsigned flags; 52886b6c1f3SDenys Vlasenko 5298c5cf9e5SDenys Vlasenko if (data & ~(unsigned long)PTRACE_O_MASK) 5308c5cf9e5SDenys Vlasenko return -EINVAL; 5318c5cf9e5SDenys Vlasenko 53286b6c1f3SDenys Vlasenko /* Avoid intermediate state when all opts are cleared */ 53386b6c1f3SDenys Vlasenko flags = child->ptrace; 53486b6c1f3SDenys Vlasenko flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); 53586b6c1f3SDenys Vlasenko flags |= (data << PT_OPT_FLAG_SHIFT); 53686b6c1f3SDenys Vlasenko child->ptrace = flags; 5371da177e4SLinus Torvalds 5388c5cf9e5SDenys Vlasenko return 0; 5391da177e4SLinus Torvalds } 5401da177e4SLinus Torvalds 541e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 5421da177e4SLinus Torvalds { 543e4961254SOleg Nesterov unsigned long flags; 5441da177e4SLinus Torvalds int error = -ESRCH; 5451da177e4SLinus Torvalds 546e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5471da177e4SLinus Torvalds error = -EINVAL; 5481da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 549e16b2781SRoland McGrath *info = *child->last_siginfo; 5501da177e4SLinus Torvalds error = 0; 5511da177e4SLinus Torvalds } 552e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5531da177e4SLinus Torvalds } 5541da177e4SLinus Torvalds return error; 5551da177e4SLinus Torvalds } 5561da177e4SLinus Torvalds 557e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 5581da177e4SLinus Torvalds { 559e4961254SOleg Nesterov unsigned long flags; 5601da177e4SLinus Torvalds int error = -ESRCH; 5611da177e4SLinus Torvalds 562e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5631da177e4SLinus Torvalds error = -EINVAL; 5641da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 565e16b2781SRoland McGrath *child->last_siginfo = *info; 5661da177e4SLinus Torvalds error = 0; 5671da177e4SLinus Torvalds } 568e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5691da177e4SLinus Torvalds } 5701da177e4SLinus Torvalds return error; 5711da177e4SLinus Torvalds } 5721da177e4SLinus Torvalds 57336df29d7SRoland McGrath 57436df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 57536df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 57636df29d7SRoland McGrath #else 57736df29d7SRoland McGrath #define is_singlestep(request) 0 57836df29d7SRoland McGrath #endif 57936df29d7SRoland McGrath 5805b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 5815b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 5825b88abbfSRoland McGrath #else 5835b88abbfSRoland McGrath #define is_singleblock(request) 0 5845b88abbfSRoland McGrath #endif 5855b88abbfSRoland McGrath 58636df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 58736df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 58836df29d7SRoland McGrath #else 58936df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 59036df29d7SRoland McGrath #endif 59136df29d7SRoland McGrath 5924abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 5934abf9869SNamhyung Kim unsigned long data) 59436df29d7SRoland McGrath { 59536df29d7SRoland McGrath if (!valid_signal(data)) 59636df29d7SRoland McGrath return -EIO; 59736df29d7SRoland McGrath 59836df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 59936df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 60036df29d7SRoland McGrath else 60136df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 60236df29d7SRoland McGrath 60336df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 60436df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 60536df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 60636df29d7SRoland McGrath else 60736df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 60836df29d7SRoland McGrath #endif 60936df29d7SRoland McGrath 6105b88abbfSRoland McGrath if (is_singleblock(request)) { 6115b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 6125b88abbfSRoland McGrath return -EIO; 6135b88abbfSRoland McGrath user_enable_block_step(child); 6145b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 61536df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 61636df29d7SRoland McGrath return -EIO; 61736df29d7SRoland McGrath user_enable_single_step(child); 6183a709703SRoland McGrath } else { 61936df29d7SRoland McGrath user_disable_single_step(child); 6203a709703SRoland McGrath } 62136df29d7SRoland McGrath 62236df29d7SRoland McGrath child->exit_code = data; 6230666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 62436df29d7SRoland McGrath 62536df29d7SRoland McGrath return 0; 62636df29d7SRoland McGrath } 62736df29d7SRoland McGrath 6282225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 6292225a122SSuresh Siddha 6302225a122SSuresh Siddha static const struct user_regset * 6312225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 6322225a122SSuresh Siddha { 6332225a122SSuresh Siddha const struct user_regset *regset; 6342225a122SSuresh Siddha int n; 6352225a122SSuresh Siddha 6362225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 6372225a122SSuresh Siddha regset = view->regsets + n; 6382225a122SSuresh Siddha if (regset->core_note_type == type) 6392225a122SSuresh Siddha return regset; 6402225a122SSuresh Siddha } 6412225a122SSuresh Siddha 6422225a122SSuresh Siddha return NULL; 6432225a122SSuresh Siddha } 6442225a122SSuresh Siddha 6452225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 6462225a122SSuresh Siddha struct iovec *kiov) 6472225a122SSuresh Siddha { 6482225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 6492225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 6502225a122SSuresh Siddha int regset_no; 6512225a122SSuresh Siddha 6522225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 653c6a0dd7eSSuresh Siddha return -EINVAL; 6542225a122SSuresh Siddha 6552225a122SSuresh Siddha regset_no = regset - view->regsets; 6562225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 6572225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 6582225a122SSuresh Siddha 6592225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 6602225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 6612225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6622225a122SSuresh Siddha else 6632225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 6642225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6652225a122SSuresh Siddha } 6662225a122SSuresh Siddha 6672225a122SSuresh Siddha #endif 6682225a122SSuresh Siddha 6691da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 6704abf9869SNamhyung Kim unsigned long addr, unsigned long data) 6711da177e4SLinus Torvalds { 672fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 6731da177e4SLinus Torvalds int ret = -EIO; 674544b2c91STejun Heo siginfo_t siginfo, *si; 6759fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 6769fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 677fca26f26STejun Heo unsigned long flags; 6781da177e4SLinus Torvalds 6791da177e4SLinus Torvalds switch (request) { 68016c3e389SRoland McGrath case PTRACE_PEEKTEXT: 68116c3e389SRoland McGrath case PTRACE_PEEKDATA: 68216c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 68316c3e389SRoland McGrath case PTRACE_POKETEXT: 68416c3e389SRoland McGrath case PTRACE_POKEDATA: 68516c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 68616c3e389SRoland McGrath 6871da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 6881da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 6891da177e4SLinus Torvalds #endif 6901da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 6911da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 6921da177e4SLinus Torvalds break; 6931da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 6949fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 6951da177e4SLinus Torvalds break; 696e16b2781SRoland McGrath 6971da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 698e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 699e16b2781SRoland McGrath if (!ret) 7009fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 7011da177e4SLinus Torvalds break; 702e16b2781SRoland McGrath 7031da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 7049fed81dcSNamhyung Kim if (copy_from_user(&siginfo, datavp, sizeof siginfo)) 705e16b2781SRoland McGrath ret = -EFAULT; 706e16b2781SRoland McGrath else 707e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 7081da177e4SLinus Torvalds break; 709e16b2781SRoland McGrath 710fca26f26STejun Heo case PTRACE_INTERRUPT: 711fca26f26STejun Heo /* 712fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 713fca26f26STejun Heo * control. At least one trap is guaranteed to happen 714fca26f26STejun Heo * after this request. If @child is already trapped, the 715fca26f26STejun Heo * current trap is not disturbed and another trap will 716fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 717fca26f26STejun Heo * 718fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 719fca26f26STejun Heo * the pending condition is cleared regardless. 720fca26f26STejun Heo */ 721fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 722fca26f26STejun Heo break; 723fca26f26STejun Heo 724544b2c91STejun Heo /* 725544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 726544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 727544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 728544b2c91STejun Heo * tracee into STOP. 729544b2c91STejun Heo */ 730fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 731544b2c91STejun Heo signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 732544b2c91STejun Heo 733544b2c91STejun Heo unlock_task_sighand(child, &flags); 734544b2c91STejun Heo ret = 0; 735544b2c91STejun Heo break; 736544b2c91STejun Heo 737544b2c91STejun Heo case PTRACE_LISTEN: 738544b2c91STejun Heo /* 739544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 740544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 741544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 742544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 743544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 744544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 745544b2c91STejun Heo */ 746544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 747544b2c91STejun Heo break; 748544b2c91STejun Heo 749544b2c91STejun Heo si = child->last_siginfo; 750f9d81f61SOleg Nesterov if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { 751544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 752544b2c91STejun Heo /* 753f9d81f61SOleg Nesterov * If NOTIFY is set, it means event happened between 754f9d81f61SOleg Nesterov * start of this trap and now. Trigger re-trap. 755544b2c91STejun Heo */ 756544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 757544b2c91STejun Heo signal_wake_up(child, true); 758fca26f26STejun Heo ret = 0; 759f9d81f61SOleg Nesterov } 760f9d81f61SOleg Nesterov unlock_task_sighand(child, &flags); 761fca26f26STejun Heo break; 762fca26f26STejun Heo 7631bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 7641bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 7651bcf5482SAlexey Dobriyan break; 76636df29d7SRoland McGrath 7679c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 7689c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 769e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 7709c1a1259SMike Frysinger unsigned long tmp = 0; 7719c1a1259SMike Frysinger 772e0129ef9SOleg Nesterov ret = -ESRCH; 773e0129ef9SOleg Nesterov if (!mm) 774e0129ef9SOleg Nesterov break; 775e0129ef9SOleg Nesterov 7769c1a1259SMike Frysinger switch (addr) { 7779c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 778e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 7799c1a1259SMike Frysinger break; 7809c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 781e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 7829c1a1259SMike Frysinger break; 7839c1a1259SMike Frysinger default: 7849c1a1259SMike Frysinger break; 7859c1a1259SMike Frysinger } 786e0129ef9SOleg Nesterov mmput(mm); 7879c1a1259SMike Frysinger 7889fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 7899c1a1259SMike Frysinger break; 7909c1a1259SMike Frysinger } 7919c1a1259SMike Frysinger #endif 7929c1a1259SMike Frysinger 79336df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 79436df29d7SRoland McGrath case PTRACE_SINGLESTEP: 79536df29d7SRoland McGrath #endif 7965b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 7975b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 7985b88abbfSRoland McGrath #endif 79936df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 80036df29d7SRoland McGrath case PTRACE_SYSEMU: 80136df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 80236df29d7SRoland McGrath #endif 80336df29d7SRoland McGrath case PTRACE_SYSCALL: 80436df29d7SRoland McGrath case PTRACE_CONT: 80536df29d7SRoland McGrath return ptrace_resume(child, request, data); 80636df29d7SRoland McGrath 80736df29d7SRoland McGrath case PTRACE_KILL: 80836df29d7SRoland McGrath if (child->exit_state) /* already dead */ 80936df29d7SRoland McGrath return 0; 81036df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 81136df29d7SRoland McGrath 8122225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8132225a122SSuresh Siddha case PTRACE_GETREGSET: 8142225a122SSuresh Siddha case PTRACE_SETREGSET: 8152225a122SSuresh Siddha { 8162225a122SSuresh Siddha struct iovec kiov; 8179fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 8182225a122SSuresh Siddha 8192225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 8202225a122SSuresh Siddha return -EFAULT; 8212225a122SSuresh Siddha 8222225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 8232225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 8242225a122SSuresh Siddha return -EFAULT; 8252225a122SSuresh Siddha 8262225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 8272225a122SSuresh Siddha if (!ret) 8282225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 8292225a122SSuresh Siddha break; 8302225a122SSuresh Siddha } 8312225a122SSuresh Siddha #endif 8321da177e4SLinus Torvalds default: 8331da177e4SLinus Torvalds break; 8341da177e4SLinus Torvalds } 8351da177e4SLinus Torvalds 8361da177e4SLinus Torvalds return ret; 8371da177e4SLinus Torvalds } 838481bed45SChristoph Hellwig 8398053bdd5SOleg Nesterov static struct task_struct *ptrace_get_task_struct(pid_t pid) 8406b9c7ed8SChristoph Hellwig { 8416b9c7ed8SChristoph Hellwig struct task_struct *child; 8426b9c7ed8SChristoph Hellwig 8438053bdd5SOleg Nesterov rcu_read_lock(); 844228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 845481bed45SChristoph Hellwig if (child) 846481bed45SChristoph Hellwig get_task_struct(child); 8478053bdd5SOleg Nesterov rcu_read_unlock(); 848f400e198SSukadev Bhattiprolu 849481bed45SChristoph Hellwig if (!child) 8506b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 8516b9c7ed8SChristoph Hellwig return child; 852481bed45SChristoph Hellwig } 853481bed45SChristoph Hellwig 8540ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 8550ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 8560ac15559SChristoph Hellwig #endif 8570ac15559SChristoph Hellwig 8584abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 8594abf9869SNamhyung Kim unsigned long, data) 860481bed45SChristoph Hellwig { 861481bed45SChristoph Hellwig struct task_struct *child; 862481bed45SChristoph Hellwig long ret; 863481bed45SChristoph Hellwig 8646b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 8656b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 8666ea6dd93SHaavard Skinnemoen if (!ret) 8676ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 868481bed45SChristoph Hellwig goto out; 8696b9c7ed8SChristoph Hellwig } 8706b9c7ed8SChristoph Hellwig 8716b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 8726b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 8736b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 8746b9c7ed8SChristoph Hellwig goto out; 8756b9c7ed8SChristoph Hellwig } 876481bed45SChristoph Hellwig 8773544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 878aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 8790ac15559SChristoph Hellwig /* 8800ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 8810ac15559SChristoph Hellwig * a ptrace attach. 8820ac15559SChristoph Hellwig */ 8830ac15559SChristoph Hellwig if (!ret) 8840ac15559SChristoph Hellwig arch_ptrace_attach(child); 885005f18dfSChristoph Hellwig goto out_put_task_struct; 886481bed45SChristoph Hellwig } 887481bed45SChristoph Hellwig 888fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 889fca26f26STejun Heo request == PTRACE_INTERRUPT); 890481bed45SChristoph Hellwig if (ret < 0) 891481bed45SChristoph Hellwig goto out_put_task_struct; 892481bed45SChristoph Hellwig 893481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 894481bed45SChristoph Hellwig 895481bed45SChristoph Hellwig out_put_task_struct: 896481bed45SChristoph Hellwig put_task_struct(child); 897481bed45SChristoph Hellwig out: 898481bed45SChristoph Hellwig return ret; 899481bed45SChristoph Hellwig } 90076647323SAlexey Dobriyan 9014abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 9024abf9869SNamhyung Kim unsigned long data) 90376647323SAlexey Dobriyan { 90476647323SAlexey Dobriyan unsigned long tmp; 90576647323SAlexey Dobriyan int copied; 90676647323SAlexey Dobriyan 90776647323SAlexey Dobriyan copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); 90876647323SAlexey Dobriyan if (copied != sizeof(tmp)) 90976647323SAlexey Dobriyan return -EIO; 91076647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 91176647323SAlexey Dobriyan } 912f284ce72SAlexey Dobriyan 9134abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 9144abf9869SNamhyung Kim unsigned long data) 915f284ce72SAlexey Dobriyan { 916f284ce72SAlexey Dobriyan int copied; 917f284ce72SAlexey Dobriyan 918f284ce72SAlexey Dobriyan copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); 919f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 920f284ce72SAlexey Dobriyan } 921032d82d9SRoland McGrath 92296b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 923032d82d9SRoland McGrath #include <linux/compat.h> 924032d82d9SRoland McGrath 925032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 926032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 927032d82d9SRoland McGrath { 928032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 929032d82d9SRoland McGrath compat_ulong_t word; 930e16b2781SRoland McGrath siginfo_t siginfo; 931032d82d9SRoland McGrath int ret; 932032d82d9SRoland McGrath 933032d82d9SRoland McGrath switch (request) { 934032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 935032d82d9SRoland McGrath case PTRACE_PEEKDATA: 936032d82d9SRoland McGrath ret = access_process_vm(child, addr, &word, sizeof(word), 0); 937032d82d9SRoland McGrath if (ret != sizeof(word)) 938032d82d9SRoland McGrath ret = -EIO; 939032d82d9SRoland McGrath else 940032d82d9SRoland McGrath ret = put_user(word, datap); 941032d82d9SRoland McGrath break; 942032d82d9SRoland McGrath 943032d82d9SRoland McGrath case PTRACE_POKETEXT: 944032d82d9SRoland McGrath case PTRACE_POKEDATA: 945032d82d9SRoland McGrath ret = access_process_vm(child, addr, &data, sizeof(data), 1); 946032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 947032d82d9SRoland McGrath break; 948032d82d9SRoland McGrath 949032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 950032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 951032d82d9SRoland McGrath break; 952032d82d9SRoland McGrath 953e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 954e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 955e16b2781SRoland McGrath if (!ret) 956e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 957e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 958e16b2781SRoland McGrath &siginfo); 959e16b2781SRoland McGrath break; 960e16b2781SRoland McGrath 961e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 962e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 963e16b2781SRoland McGrath if (copy_siginfo_from_user32( 964e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 965e16b2781SRoland McGrath ret = -EFAULT; 966e16b2781SRoland McGrath else 967e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 968e16b2781SRoland McGrath break; 9692225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 9702225a122SSuresh Siddha case PTRACE_GETREGSET: 9712225a122SSuresh Siddha case PTRACE_SETREGSET: 9722225a122SSuresh Siddha { 9732225a122SSuresh Siddha struct iovec kiov; 9742225a122SSuresh Siddha struct compat_iovec __user *uiov = 9752225a122SSuresh Siddha (struct compat_iovec __user *) datap; 9762225a122SSuresh Siddha compat_uptr_t ptr; 9772225a122SSuresh Siddha compat_size_t len; 9782225a122SSuresh Siddha 9792225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 9802225a122SSuresh Siddha return -EFAULT; 9812225a122SSuresh Siddha 9822225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 9832225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 9842225a122SSuresh Siddha return -EFAULT; 9852225a122SSuresh Siddha 9862225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 9872225a122SSuresh Siddha kiov.iov_len = len; 9882225a122SSuresh Siddha 9892225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 9902225a122SSuresh Siddha if (!ret) 9912225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 9922225a122SSuresh Siddha break; 9932225a122SSuresh Siddha } 9942225a122SSuresh Siddha #endif 995e16b2781SRoland McGrath 996032d82d9SRoland McGrath default: 997032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 998032d82d9SRoland McGrath } 999032d82d9SRoland McGrath 1000032d82d9SRoland McGrath return ret; 1001032d82d9SRoland McGrath } 1002c269f196SRoland McGrath 1003c269f196SRoland McGrath asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, 1004c269f196SRoland McGrath compat_long_t addr, compat_long_t data) 1005c269f196SRoland McGrath { 1006c269f196SRoland McGrath struct task_struct *child; 1007c269f196SRoland McGrath long ret; 1008c269f196SRoland McGrath 1009c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1010c269f196SRoland McGrath ret = ptrace_traceme(); 1011c269f196SRoland McGrath goto out; 1012c269f196SRoland McGrath } 1013c269f196SRoland McGrath 1014c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 1015c269f196SRoland McGrath if (IS_ERR(child)) { 1016c269f196SRoland McGrath ret = PTR_ERR(child); 1017c269f196SRoland McGrath goto out; 1018c269f196SRoland McGrath } 1019c269f196SRoland McGrath 10203544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1021aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 1022c269f196SRoland McGrath /* 1023c269f196SRoland McGrath * Some architectures need to do book-keeping after 1024c269f196SRoland McGrath * a ptrace attach. 1025c269f196SRoland McGrath */ 1026c269f196SRoland McGrath if (!ret) 1027c269f196SRoland McGrath arch_ptrace_attach(child); 1028c269f196SRoland McGrath goto out_put_task_struct; 1029c269f196SRoland McGrath } 1030c269f196SRoland McGrath 1031fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1032fca26f26STejun Heo request == PTRACE_INTERRUPT); 1033c269f196SRoland McGrath if (!ret) 1034c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 1035c269f196SRoland McGrath 1036c269f196SRoland McGrath out_put_task_struct: 1037c269f196SRoland McGrath put_task_struct(child); 1038c269f196SRoland McGrath out: 1039c269f196SRoland McGrath return ret; 1040c269f196SRoland McGrath } 104196b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1042bf26c018SFrederic Weisbecker 1043bf26c018SFrederic Weisbecker #ifdef CONFIG_HAVE_HW_BREAKPOINT 1044bf26c018SFrederic Weisbecker int ptrace_get_breakpoints(struct task_struct *tsk) 1045bf26c018SFrederic Weisbecker { 1046bf26c018SFrederic Weisbecker if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) 1047bf26c018SFrederic Weisbecker return 0; 1048bf26c018SFrederic Weisbecker 1049bf26c018SFrederic Weisbecker return -1; 1050bf26c018SFrederic Weisbecker } 1051bf26c018SFrederic Weisbecker 1052bf26c018SFrederic Weisbecker void ptrace_put_breakpoints(struct task_struct *tsk) 1053bf26c018SFrederic Weisbecker { 1054bf26c018SFrederic Weisbecker if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) 1055bf26c018SFrederic Weisbecker flush_ptrace_hw_breakpoint(tsk); 1056bf26c018SFrederic Weisbecker } 1057bf26c018SFrederic Weisbecker #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 1058