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)) 120910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 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 */ 142edea0d03SOleg Nesterov static 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 1839f99798fSTetsuo Handa /* Returns 0 on success, -errno on denial. */ 1849f99798fSTetsuo Handa static int __ptrace_may_access(struct task_struct *task, unsigned int mode) 185ab8d11beSMiklos Szeredi { 186c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 187b6dff3ecSDavid Howells 188df26c40eSEric W. Biederman /* May we inspect the given task? 189df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 190df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 191df26c40eSEric W. Biederman * 192df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 193df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 194df26c40eSEric W. Biederman * or halting the specified task is impossible. 195df26c40eSEric W. Biederman */ 196df26c40eSEric W. Biederman int dumpable = 0; 197df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 198df26c40eSEric W. Biederman if (task == current) 199df26c40eSEric W. Biederman return 0; 200c69e8d9cSDavid Howells rcu_read_lock(); 201c69e8d9cSDavid Howells tcred = __task_cred(task); 2025af66203SEric W. Biederman if (uid_eq(cred->uid, tcred->euid) && 2035af66203SEric W. Biederman uid_eq(cred->uid, tcred->suid) && 2045af66203SEric W. Biederman uid_eq(cred->uid, tcred->uid) && 2055af66203SEric W. Biederman gid_eq(cred->gid, tcred->egid) && 2065af66203SEric W. Biederman gid_eq(cred->gid, tcred->sgid) && 2075af66203SEric W. Biederman gid_eq(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); 2184c44aaafSEric W. Biederman rcu_read_lock(); 2194c44aaafSEric W. Biederman if (!dumpable && !ptrace_has_cap(__task_cred(task)->user_ns, mode)) { 2204c44aaafSEric W. Biederman rcu_read_unlock(); 221ab8d11beSMiklos Szeredi return -EPERM; 2224c44aaafSEric W. Biederman } 2234c44aaafSEric W. Biederman rcu_read_unlock(); 224ab8d11beSMiklos Szeredi 2259e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 226ab8d11beSMiklos Szeredi } 227ab8d11beSMiklos Szeredi 228006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 229ab8d11beSMiklos Szeredi { 230ab8d11beSMiklos Szeredi int err; 231ab8d11beSMiklos Szeredi task_lock(task); 232006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 233ab8d11beSMiklos Szeredi task_unlock(task); 2343a709703SRoland McGrath return !err; 235ab8d11beSMiklos Szeredi } 236ab8d11beSMiklos Szeredi 2373544d72aSTejun Heo static int ptrace_attach(struct task_struct *task, long request, 238aa9147c9SDenys Vlasenko unsigned long addr, 2393544d72aSTejun Heo unsigned long flags) 2401da177e4SLinus Torvalds { 2413544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 2421da177e4SLinus Torvalds int retval; 243f5b40e36SLinus Torvalds 2443544d72aSTejun Heo retval = -EIO; 245aa9147c9SDenys Vlasenko if (seize) { 246aa9147c9SDenys Vlasenko if (addr != 0) 2473544d72aSTejun Heo goto out; 248aa9147c9SDenys Vlasenko if (flags & ~(unsigned long)PTRACE_O_MASK) 249aa9147c9SDenys Vlasenko goto out; 250aa9147c9SDenys Vlasenko flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); 251aa9147c9SDenys Vlasenko } else { 252aa9147c9SDenys Vlasenko flags = PT_PTRACED; 253aa9147c9SDenys Vlasenko } 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; 26586b6c1f3SDenys Vlasenko * 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 2853544d72aSTejun Heo if (seize) 286aa9147c9SDenys Vlasenko flags |= PT_SEIZED; 2874c44aaafSEric W. Biederman rcu_read_lock(); 2884c44aaafSEric W. Biederman if (ns_capable(__task_cred(task)->user_ns, CAP_SYS_PTRACE)) 289aa9147c9SDenys Vlasenko flags |= PT_PTRACE_CAP; 2904c44aaafSEric W. Biederman rcu_read_unlock(); 291aa9147c9SDenys Vlasenko task->ptrace = flags; 2921da177e4SLinus Torvalds 2931da177e4SLinus Torvalds __ptrace_link(task, current); 2943544d72aSTejun Heo 2953544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 2963544d72aSTejun Heo if (!seize) 29733e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 298b79b7ba9SOleg Nesterov 299d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 300d79fdd6dSTejun Heo 301d79fdd6dSTejun Heo /* 30273ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 303d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 304d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 305d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 306d79fdd6dSTejun Heo * for the transition to complete before returning from this 307d79fdd6dSTejun Heo * function. 308d79fdd6dSTejun Heo * 309d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 310d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 311d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 312d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 313d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 314d79fdd6dSTejun Heo * 315d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 316d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 317d79fdd6dSTejun Heo */ 3187dd3db54STejun Heo if (task_is_stopped(task) && 31973ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 320910ffdb1SOleg Nesterov signal_wake_up_state(task, __TASK_STOPPED); 321d79fdd6dSTejun Heo 322d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 323d79fdd6dSTejun Heo 324b79b7ba9SOleg Nesterov retval = 0; 3254b105cbbSOleg Nesterov unlock_tasklist: 3264b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3274b105cbbSOleg Nesterov unlock_creds: 3289b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 329f5b40e36SLinus Torvalds out: 330f701e5b7SVladimir Zapolskiy if (!retval) { 33162c124ffSTejun Heo wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, 33262c124ffSTejun Heo ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE); 333f701e5b7SVladimir Zapolskiy proc_ptrace_connector(task, PTRACE_ATTACH); 334f701e5b7SVladimir Zapolskiy } 335f701e5b7SVladimir Zapolskiy 3361da177e4SLinus Torvalds return retval; 3371da177e4SLinus Torvalds } 3381da177e4SLinus Torvalds 339f2f0b00aSOleg Nesterov /** 340f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 341f2f0b00aSOleg Nesterov * 342f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 343f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 344f2f0b00aSOleg Nesterov */ 345e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 346f2f0b00aSOleg Nesterov { 347f2f0b00aSOleg Nesterov int ret = -EPERM; 348f2f0b00aSOleg Nesterov 3494b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 3504b105cbbSOleg Nesterov /* Are we already being traced? */ 351f2f0b00aSOleg Nesterov if (!current->ptrace) { 352f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 353f2f0b00aSOleg Nesterov /* 354f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 355f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 356f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 357f2f0b00aSOleg Nesterov */ 358f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 359f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 360f2f0b00aSOleg Nesterov __ptrace_link(current, current->real_parent); 361f2f0b00aSOleg Nesterov } 362f2f0b00aSOleg Nesterov } 3634b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3644b105cbbSOleg Nesterov 365f2f0b00aSOleg Nesterov return ret; 366f2f0b00aSOleg Nesterov } 367f2f0b00aSOleg Nesterov 36839c626aeSOleg Nesterov /* 36939c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 37039c626aeSOleg Nesterov */ 37139c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 37239c626aeSOleg Nesterov { 37339c626aeSOleg Nesterov int ret; 37439c626aeSOleg Nesterov spin_lock(&sigh->siglock); 37539c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 37639c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 37739c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 37839c626aeSOleg Nesterov return ret; 37939c626aeSOleg Nesterov } 38039c626aeSOleg Nesterov 38139c626aeSOleg Nesterov /* 38239c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 38339c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 38439c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 38539c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 38639c626aeSOleg Nesterov * 38739c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 38839c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 38939c626aeSOleg Nesterov * If it should reap itself, return true. 39039c626aeSOleg Nesterov * 391a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 392a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 393a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 394a7f0765eSOleg Nesterov * do_wait(). 39539c626aeSOleg Nesterov */ 39639c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 39739c626aeSOleg Nesterov { 3989843a1e9SOleg Nesterov bool dead; 3999843a1e9SOleg Nesterov 40039c626aeSOleg Nesterov __ptrace_unlink(p); 40139c626aeSOleg Nesterov 4029843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 4039843a1e9SOleg Nesterov return false; 4049843a1e9SOleg Nesterov 4059843a1e9SOleg Nesterov dead = !thread_group_leader(p); 4069843a1e9SOleg Nesterov 4079843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 40839c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 4099843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 410a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 411a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 4129843a1e9SOleg Nesterov dead = true; 41339c626aeSOleg Nesterov } 414a7f0765eSOleg Nesterov } 41539c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 4169843a1e9SOleg Nesterov if (dead) 41739c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 4189843a1e9SOleg Nesterov return dead; 41939c626aeSOleg Nesterov } 42039c626aeSOleg Nesterov 421e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 4221da177e4SLinus Torvalds { 42339c626aeSOleg Nesterov bool dead = false; 4244576145cSOleg Nesterov 4257ed20e1aSJesper Juhl if (!valid_signal(data)) 4261da177e4SLinus Torvalds return -EIO; 4271da177e4SLinus Torvalds 4281da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 4291da177e4SLinus Torvalds ptrace_disable(child); 4307d941432SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 4311da177e4SLinus Torvalds 43295c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 43339c626aeSOleg Nesterov /* 43439c626aeSOleg Nesterov * This child can be already killed. Make sure de_thread() or 43539c626aeSOleg Nesterov * our sub-thread doing do_wait() didn't do release_task() yet. 43639c626aeSOleg Nesterov */ 43795c3eb76SOleg Nesterov if (child->ptrace) { 43895c3eb76SOleg Nesterov child->exit_code = data; 4394576145cSOleg Nesterov dead = __ptrace_detach(current, child); 44095c3eb76SOleg Nesterov } 4411da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 4421da177e4SLinus Torvalds 443f701e5b7SVladimir Zapolskiy proc_ptrace_connector(child, PTRACE_DETACH); 4444576145cSOleg Nesterov if (unlikely(dead)) 4454576145cSOleg Nesterov release_task(child); 4464576145cSOleg Nesterov 4471da177e4SLinus Torvalds return 0; 4481da177e4SLinus Torvalds } 4491da177e4SLinus Torvalds 45039c626aeSOleg Nesterov /* 451c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 452c7e49c14SOleg Nesterov * for writing, and returns with it held too. But note it can release 453c7e49c14SOleg Nesterov * and reacquire the lock. 45439c626aeSOleg Nesterov */ 45539c626aeSOleg Nesterov void exit_ptrace(struct task_struct *tracer) 456c4b5ed25SNamhyung Kim __releases(&tasklist_lock) 457c4b5ed25SNamhyung Kim __acquires(&tasklist_lock) 45839c626aeSOleg Nesterov { 45939c626aeSOleg Nesterov struct task_struct *p, *n; 46039c626aeSOleg Nesterov LIST_HEAD(ptrace_dead); 46139c626aeSOleg Nesterov 462c7e49c14SOleg Nesterov if (likely(list_empty(&tracer->ptraced))) 463c7e49c14SOleg Nesterov return; 464c7e49c14SOleg Nesterov 46539c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 466992fb6e1SOleg Nesterov if (unlikely(p->ptrace & PT_EXITKILL)) 467992fb6e1SOleg Nesterov send_sig_info(SIGKILL, SEND_SIG_FORCED, p); 468992fb6e1SOleg Nesterov 46939c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 47039c626aeSOleg Nesterov list_add(&p->ptrace_entry, &ptrace_dead); 47139c626aeSOleg Nesterov } 47239c626aeSOleg Nesterov 473c7e49c14SOleg Nesterov write_unlock_irq(&tasklist_lock); 47439c626aeSOleg Nesterov BUG_ON(!list_empty(&tracer->ptraced)); 47539c626aeSOleg Nesterov 47639c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { 47739c626aeSOleg Nesterov list_del_init(&p->ptrace_entry); 47839c626aeSOleg Nesterov release_task(p); 47939c626aeSOleg Nesterov } 480c7e49c14SOleg Nesterov 481c7e49c14SOleg Nesterov write_lock_irq(&tasklist_lock); 48239c626aeSOleg Nesterov } 48339c626aeSOleg Nesterov 4841da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 4851da177e4SLinus Torvalds { 4861da177e4SLinus Torvalds int copied = 0; 4871da177e4SLinus Torvalds 4881da177e4SLinus Torvalds while (len > 0) { 4891da177e4SLinus Torvalds char buf[128]; 4901da177e4SLinus Torvalds int this_len, retval; 4911da177e4SLinus Torvalds 4921da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4931da177e4SLinus Torvalds retval = access_process_vm(tsk, src, buf, this_len, 0); 4941da177e4SLinus Torvalds if (!retval) { 4951da177e4SLinus Torvalds if (copied) 4961da177e4SLinus Torvalds break; 4971da177e4SLinus Torvalds return -EIO; 4981da177e4SLinus Torvalds } 4991da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 5001da177e4SLinus Torvalds return -EFAULT; 5011da177e4SLinus Torvalds copied += retval; 5021da177e4SLinus Torvalds src += retval; 5031da177e4SLinus Torvalds dst += retval; 5041da177e4SLinus Torvalds len -= retval; 5051da177e4SLinus Torvalds } 5061da177e4SLinus Torvalds return copied; 5071da177e4SLinus Torvalds } 5081da177e4SLinus Torvalds 5091da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 5101da177e4SLinus Torvalds { 5111da177e4SLinus Torvalds int copied = 0; 5121da177e4SLinus Torvalds 5131da177e4SLinus Torvalds while (len > 0) { 5141da177e4SLinus Torvalds char buf[128]; 5151da177e4SLinus Torvalds int this_len, retval; 5161da177e4SLinus Torvalds 5171da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 5181da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 5191da177e4SLinus Torvalds return -EFAULT; 5201da177e4SLinus Torvalds retval = access_process_vm(tsk, dst, buf, this_len, 1); 5211da177e4SLinus Torvalds if (!retval) { 5221da177e4SLinus Torvalds if (copied) 5231da177e4SLinus Torvalds break; 5241da177e4SLinus Torvalds return -EIO; 5251da177e4SLinus Torvalds } 5261da177e4SLinus Torvalds copied += retval; 5271da177e4SLinus Torvalds src += retval; 5281da177e4SLinus Torvalds dst += retval; 5291da177e4SLinus Torvalds len -= retval; 5301da177e4SLinus Torvalds } 5311da177e4SLinus Torvalds return copied; 5321da177e4SLinus Torvalds } 5331da177e4SLinus Torvalds 5344abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 5351da177e4SLinus Torvalds { 53686b6c1f3SDenys Vlasenko unsigned flags; 53786b6c1f3SDenys Vlasenko 5388c5cf9e5SDenys Vlasenko if (data & ~(unsigned long)PTRACE_O_MASK) 5398c5cf9e5SDenys Vlasenko return -EINVAL; 5408c5cf9e5SDenys Vlasenko 54186b6c1f3SDenys Vlasenko /* Avoid intermediate state when all opts are cleared */ 54286b6c1f3SDenys Vlasenko flags = child->ptrace; 54386b6c1f3SDenys Vlasenko flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); 54486b6c1f3SDenys Vlasenko flags |= (data << PT_OPT_FLAG_SHIFT); 54586b6c1f3SDenys Vlasenko child->ptrace = flags; 5461da177e4SLinus Torvalds 5478c5cf9e5SDenys Vlasenko return 0; 5481da177e4SLinus Torvalds } 5491da177e4SLinus Torvalds 550e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 5511da177e4SLinus Torvalds { 552e4961254SOleg Nesterov unsigned long flags; 5531da177e4SLinus Torvalds int error = -ESRCH; 5541da177e4SLinus Torvalds 555e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5561da177e4SLinus Torvalds error = -EINVAL; 5571da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 558e16b2781SRoland McGrath *info = *child->last_siginfo; 5591da177e4SLinus Torvalds error = 0; 5601da177e4SLinus Torvalds } 561e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5621da177e4SLinus Torvalds } 5631da177e4SLinus Torvalds return error; 5641da177e4SLinus Torvalds } 5651da177e4SLinus Torvalds 566e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 5671da177e4SLinus Torvalds { 568e4961254SOleg Nesterov unsigned long flags; 5691da177e4SLinus Torvalds int error = -ESRCH; 5701da177e4SLinus Torvalds 571e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5721da177e4SLinus Torvalds error = -EINVAL; 5731da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 574e16b2781SRoland McGrath *child->last_siginfo = *info; 5751da177e4SLinus Torvalds error = 0; 5761da177e4SLinus Torvalds } 577e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5781da177e4SLinus Torvalds } 5791da177e4SLinus Torvalds return error; 5801da177e4SLinus Torvalds } 5811da177e4SLinus Torvalds 58236df29d7SRoland McGrath 58336df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 58436df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 58536df29d7SRoland McGrath #else 58636df29d7SRoland McGrath #define is_singlestep(request) 0 58736df29d7SRoland McGrath #endif 58836df29d7SRoland McGrath 5895b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 5905b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 5915b88abbfSRoland McGrath #else 5925b88abbfSRoland McGrath #define is_singleblock(request) 0 5935b88abbfSRoland McGrath #endif 5945b88abbfSRoland McGrath 59536df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 59636df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 59736df29d7SRoland McGrath #else 59836df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 59936df29d7SRoland McGrath #endif 60036df29d7SRoland McGrath 6014abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 6024abf9869SNamhyung Kim unsigned long data) 60336df29d7SRoland McGrath { 60436df29d7SRoland McGrath if (!valid_signal(data)) 60536df29d7SRoland McGrath return -EIO; 60636df29d7SRoland McGrath 60736df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 60836df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 60936df29d7SRoland McGrath else 61036df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 61136df29d7SRoland McGrath 61236df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 61336df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 61436df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 61536df29d7SRoland McGrath else 61636df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 61736df29d7SRoland McGrath #endif 61836df29d7SRoland McGrath 6195b88abbfSRoland McGrath if (is_singleblock(request)) { 6205b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 6215b88abbfSRoland McGrath return -EIO; 6225b88abbfSRoland McGrath user_enable_block_step(child); 6235b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 62436df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 62536df29d7SRoland McGrath return -EIO; 62636df29d7SRoland McGrath user_enable_single_step(child); 6273a709703SRoland McGrath } else { 62836df29d7SRoland McGrath user_disable_single_step(child); 6293a709703SRoland McGrath } 63036df29d7SRoland McGrath 63136df29d7SRoland McGrath child->exit_code = data; 6320666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 63336df29d7SRoland McGrath 63436df29d7SRoland McGrath return 0; 63536df29d7SRoland McGrath } 63636df29d7SRoland McGrath 6372225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 6382225a122SSuresh Siddha 6392225a122SSuresh Siddha static const struct user_regset * 6402225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 6412225a122SSuresh Siddha { 6422225a122SSuresh Siddha const struct user_regset *regset; 6432225a122SSuresh Siddha int n; 6442225a122SSuresh Siddha 6452225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 6462225a122SSuresh Siddha regset = view->regsets + n; 6472225a122SSuresh Siddha if (regset->core_note_type == type) 6482225a122SSuresh Siddha return regset; 6492225a122SSuresh Siddha } 6502225a122SSuresh Siddha 6512225a122SSuresh Siddha return NULL; 6522225a122SSuresh Siddha } 6532225a122SSuresh Siddha 6542225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 6552225a122SSuresh Siddha struct iovec *kiov) 6562225a122SSuresh Siddha { 6572225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 6582225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 6592225a122SSuresh Siddha int regset_no; 6602225a122SSuresh Siddha 6612225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 662c6a0dd7eSSuresh Siddha return -EINVAL; 6632225a122SSuresh Siddha 6642225a122SSuresh Siddha regset_no = regset - view->regsets; 6652225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 6662225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 6672225a122SSuresh Siddha 6682225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 6692225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 6702225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6712225a122SSuresh Siddha else 6722225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 6732225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6742225a122SSuresh Siddha } 6752225a122SSuresh Siddha 6762225a122SSuresh Siddha #endif 6772225a122SSuresh Siddha 6781da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 6794abf9869SNamhyung Kim unsigned long addr, unsigned long data) 6801da177e4SLinus Torvalds { 681fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 6821da177e4SLinus Torvalds int ret = -EIO; 683544b2c91STejun Heo siginfo_t siginfo, *si; 6849fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 6859fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 686fca26f26STejun Heo unsigned long flags; 6871da177e4SLinus Torvalds 6881da177e4SLinus Torvalds switch (request) { 68916c3e389SRoland McGrath case PTRACE_PEEKTEXT: 69016c3e389SRoland McGrath case PTRACE_PEEKDATA: 69116c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 69216c3e389SRoland McGrath case PTRACE_POKETEXT: 69316c3e389SRoland McGrath case PTRACE_POKEDATA: 69416c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 69516c3e389SRoland McGrath 6961da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 6971da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 6981da177e4SLinus Torvalds #endif 6991da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 7001da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 7011da177e4SLinus Torvalds break; 7021da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 7039fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 7041da177e4SLinus Torvalds break; 705e16b2781SRoland McGrath 7061da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 707e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 708e16b2781SRoland McGrath if (!ret) 7099fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 7101da177e4SLinus Torvalds break; 711e16b2781SRoland McGrath 7121da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 7139fed81dcSNamhyung Kim if (copy_from_user(&siginfo, datavp, sizeof siginfo)) 714e16b2781SRoland McGrath ret = -EFAULT; 715e16b2781SRoland McGrath else 716e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 7171da177e4SLinus Torvalds break; 718e16b2781SRoland McGrath 719fca26f26STejun Heo case PTRACE_INTERRUPT: 720fca26f26STejun Heo /* 721fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 722fca26f26STejun Heo * control. At least one trap is guaranteed to happen 723fca26f26STejun Heo * after this request. If @child is already trapped, the 724fca26f26STejun Heo * current trap is not disturbed and another trap will 725fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 726fca26f26STejun Heo * 727fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 728fca26f26STejun Heo * the pending condition is cleared regardless. 729fca26f26STejun Heo */ 730fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 731fca26f26STejun Heo break; 732fca26f26STejun Heo 733544b2c91STejun Heo /* 734544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 735544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 736544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 737544b2c91STejun Heo * tracee into STOP. 738544b2c91STejun Heo */ 739fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 740910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 741544b2c91STejun Heo 742544b2c91STejun Heo unlock_task_sighand(child, &flags); 743544b2c91STejun Heo ret = 0; 744544b2c91STejun Heo break; 745544b2c91STejun Heo 746544b2c91STejun Heo case PTRACE_LISTEN: 747544b2c91STejun Heo /* 748544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 749544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 750544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 751544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 752544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 753544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 754544b2c91STejun Heo */ 755544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 756544b2c91STejun Heo break; 757544b2c91STejun Heo 758544b2c91STejun Heo si = child->last_siginfo; 759f9d81f61SOleg Nesterov if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { 760544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 761544b2c91STejun Heo /* 762f9d81f61SOleg Nesterov * If NOTIFY is set, it means event happened between 763f9d81f61SOleg Nesterov * start of this trap and now. Trigger re-trap. 764544b2c91STejun Heo */ 765544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 766910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 767fca26f26STejun Heo ret = 0; 768f9d81f61SOleg Nesterov } 769f9d81f61SOleg Nesterov unlock_task_sighand(child, &flags); 770fca26f26STejun Heo break; 771fca26f26STejun Heo 7721bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 7731bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 7741bcf5482SAlexey Dobriyan break; 77536df29d7SRoland McGrath 7769c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 7779c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 778e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 7799c1a1259SMike Frysinger unsigned long tmp = 0; 7809c1a1259SMike Frysinger 781e0129ef9SOleg Nesterov ret = -ESRCH; 782e0129ef9SOleg Nesterov if (!mm) 783e0129ef9SOleg Nesterov break; 784e0129ef9SOleg Nesterov 7859c1a1259SMike Frysinger switch (addr) { 7869c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 787e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 7889c1a1259SMike Frysinger break; 7899c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 790e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 7919c1a1259SMike Frysinger break; 7929c1a1259SMike Frysinger default: 7939c1a1259SMike Frysinger break; 7949c1a1259SMike Frysinger } 795e0129ef9SOleg Nesterov mmput(mm); 7969c1a1259SMike Frysinger 7979fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 7989c1a1259SMike Frysinger break; 7999c1a1259SMike Frysinger } 8009c1a1259SMike Frysinger #endif 8019c1a1259SMike Frysinger 80236df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 80336df29d7SRoland McGrath case PTRACE_SINGLESTEP: 80436df29d7SRoland McGrath #endif 8055b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 8065b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 8075b88abbfSRoland McGrath #endif 80836df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 80936df29d7SRoland McGrath case PTRACE_SYSEMU: 81036df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 81136df29d7SRoland McGrath #endif 81236df29d7SRoland McGrath case PTRACE_SYSCALL: 81336df29d7SRoland McGrath case PTRACE_CONT: 81436df29d7SRoland McGrath return ptrace_resume(child, request, data); 81536df29d7SRoland McGrath 81636df29d7SRoland McGrath case PTRACE_KILL: 81736df29d7SRoland McGrath if (child->exit_state) /* already dead */ 81836df29d7SRoland McGrath return 0; 81936df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 82036df29d7SRoland McGrath 8212225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8222225a122SSuresh Siddha case PTRACE_GETREGSET: 8232225a122SSuresh Siddha case PTRACE_SETREGSET: 8242225a122SSuresh Siddha { 8252225a122SSuresh Siddha struct iovec kiov; 8269fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 8272225a122SSuresh Siddha 8282225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 8292225a122SSuresh Siddha return -EFAULT; 8302225a122SSuresh Siddha 8312225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 8322225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 8332225a122SSuresh Siddha return -EFAULT; 8342225a122SSuresh Siddha 8352225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 8362225a122SSuresh Siddha if (!ret) 8372225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 8382225a122SSuresh Siddha break; 8392225a122SSuresh Siddha } 8402225a122SSuresh Siddha #endif 8411da177e4SLinus Torvalds default: 8421da177e4SLinus Torvalds break; 8431da177e4SLinus Torvalds } 8441da177e4SLinus Torvalds 8451da177e4SLinus Torvalds return ret; 8461da177e4SLinus Torvalds } 847481bed45SChristoph Hellwig 8488053bdd5SOleg Nesterov static struct task_struct *ptrace_get_task_struct(pid_t pid) 8496b9c7ed8SChristoph Hellwig { 8506b9c7ed8SChristoph Hellwig struct task_struct *child; 8516b9c7ed8SChristoph Hellwig 8528053bdd5SOleg Nesterov rcu_read_lock(); 853228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 854481bed45SChristoph Hellwig if (child) 855481bed45SChristoph Hellwig get_task_struct(child); 8568053bdd5SOleg Nesterov rcu_read_unlock(); 857f400e198SSukadev Bhattiprolu 858481bed45SChristoph Hellwig if (!child) 8596b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 8606b9c7ed8SChristoph Hellwig return child; 861481bed45SChristoph Hellwig } 862481bed45SChristoph Hellwig 8630ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 8640ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 8650ac15559SChristoph Hellwig #endif 8660ac15559SChristoph Hellwig 8674abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 8684abf9869SNamhyung Kim unsigned long, data) 869481bed45SChristoph Hellwig { 870481bed45SChristoph Hellwig struct task_struct *child; 871481bed45SChristoph Hellwig long ret; 872481bed45SChristoph Hellwig 8736b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 8746b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 8756ea6dd93SHaavard Skinnemoen if (!ret) 8766ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 877481bed45SChristoph Hellwig goto out; 8786b9c7ed8SChristoph Hellwig } 8796b9c7ed8SChristoph Hellwig 8806b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 8816b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 8826b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 8836b9c7ed8SChristoph Hellwig goto out; 8846b9c7ed8SChristoph Hellwig } 885481bed45SChristoph Hellwig 8863544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 887aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 8880ac15559SChristoph Hellwig /* 8890ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 8900ac15559SChristoph Hellwig * a ptrace attach. 8910ac15559SChristoph Hellwig */ 8920ac15559SChristoph Hellwig if (!ret) 8930ac15559SChristoph Hellwig arch_ptrace_attach(child); 894005f18dfSChristoph Hellwig goto out_put_task_struct; 895481bed45SChristoph Hellwig } 896481bed45SChristoph Hellwig 897fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 898fca26f26STejun Heo request == PTRACE_INTERRUPT); 899481bed45SChristoph Hellwig if (ret < 0) 900481bed45SChristoph Hellwig goto out_put_task_struct; 901481bed45SChristoph Hellwig 902481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 903481bed45SChristoph Hellwig 904481bed45SChristoph Hellwig out_put_task_struct: 905481bed45SChristoph Hellwig put_task_struct(child); 906481bed45SChristoph Hellwig out: 907481bed45SChristoph Hellwig return ret; 908481bed45SChristoph Hellwig } 90976647323SAlexey Dobriyan 9104abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 9114abf9869SNamhyung Kim unsigned long data) 91276647323SAlexey Dobriyan { 91376647323SAlexey Dobriyan unsigned long tmp; 91476647323SAlexey Dobriyan int copied; 91576647323SAlexey Dobriyan 91676647323SAlexey Dobriyan copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); 91776647323SAlexey Dobriyan if (copied != sizeof(tmp)) 91876647323SAlexey Dobriyan return -EIO; 91976647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 92076647323SAlexey Dobriyan } 921f284ce72SAlexey Dobriyan 9224abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 9234abf9869SNamhyung Kim unsigned long data) 924f284ce72SAlexey Dobriyan { 925f284ce72SAlexey Dobriyan int copied; 926f284ce72SAlexey Dobriyan 927f284ce72SAlexey Dobriyan copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); 928f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 929f284ce72SAlexey Dobriyan } 930032d82d9SRoland McGrath 93196b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 932032d82d9SRoland McGrath #include <linux/compat.h> 933032d82d9SRoland McGrath 934032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 935032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 936032d82d9SRoland McGrath { 937032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 938032d82d9SRoland McGrath compat_ulong_t word; 939e16b2781SRoland McGrath siginfo_t siginfo; 940032d82d9SRoland McGrath int ret; 941032d82d9SRoland McGrath 942032d82d9SRoland McGrath switch (request) { 943032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 944032d82d9SRoland McGrath case PTRACE_PEEKDATA: 945032d82d9SRoland McGrath ret = access_process_vm(child, addr, &word, sizeof(word), 0); 946032d82d9SRoland McGrath if (ret != sizeof(word)) 947032d82d9SRoland McGrath ret = -EIO; 948032d82d9SRoland McGrath else 949032d82d9SRoland McGrath ret = put_user(word, datap); 950032d82d9SRoland McGrath break; 951032d82d9SRoland McGrath 952032d82d9SRoland McGrath case PTRACE_POKETEXT: 953032d82d9SRoland McGrath case PTRACE_POKEDATA: 954032d82d9SRoland McGrath ret = access_process_vm(child, addr, &data, sizeof(data), 1); 955032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 956032d82d9SRoland McGrath break; 957032d82d9SRoland McGrath 958032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 959032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 960032d82d9SRoland McGrath break; 961032d82d9SRoland McGrath 962e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 963e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 964e16b2781SRoland McGrath if (!ret) 965e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 966e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 967e16b2781SRoland McGrath &siginfo); 968e16b2781SRoland McGrath break; 969e16b2781SRoland McGrath 970e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 971e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 972e16b2781SRoland McGrath if (copy_siginfo_from_user32( 973e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 974e16b2781SRoland McGrath ret = -EFAULT; 975e16b2781SRoland McGrath else 976e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 977e16b2781SRoland McGrath break; 9782225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 9792225a122SSuresh Siddha case PTRACE_GETREGSET: 9802225a122SSuresh Siddha case PTRACE_SETREGSET: 9812225a122SSuresh Siddha { 9822225a122SSuresh Siddha struct iovec kiov; 9832225a122SSuresh Siddha struct compat_iovec __user *uiov = 9842225a122SSuresh Siddha (struct compat_iovec __user *) datap; 9852225a122SSuresh Siddha compat_uptr_t ptr; 9862225a122SSuresh Siddha compat_size_t len; 9872225a122SSuresh Siddha 9882225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 9892225a122SSuresh Siddha return -EFAULT; 9902225a122SSuresh Siddha 9912225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 9922225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 9932225a122SSuresh Siddha return -EFAULT; 9942225a122SSuresh Siddha 9952225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 9962225a122SSuresh Siddha kiov.iov_len = len; 9972225a122SSuresh Siddha 9982225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 9992225a122SSuresh Siddha if (!ret) 10002225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 10012225a122SSuresh Siddha break; 10022225a122SSuresh Siddha } 10032225a122SSuresh Siddha #endif 1004e16b2781SRoland McGrath 1005032d82d9SRoland McGrath default: 1006032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 1007032d82d9SRoland McGrath } 1008032d82d9SRoland McGrath 1009032d82d9SRoland McGrath return ret; 1010032d82d9SRoland McGrath } 1011c269f196SRoland McGrath 1012c269f196SRoland McGrath asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, 1013c269f196SRoland McGrath compat_long_t addr, compat_long_t data) 1014c269f196SRoland McGrath { 1015c269f196SRoland McGrath struct task_struct *child; 1016c269f196SRoland McGrath long ret; 1017c269f196SRoland McGrath 1018c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1019c269f196SRoland McGrath ret = ptrace_traceme(); 1020c269f196SRoland McGrath goto out; 1021c269f196SRoland McGrath } 1022c269f196SRoland McGrath 1023c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 1024c269f196SRoland McGrath if (IS_ERR(child)) { 1025c269f196SRoland McGrath ret = PTR_ERR(child); 1026c269f196SRoland McGrath goto out; 1027c269f196SRoland McGrath } 1028c269f196SRoland McGrath 10293544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1030aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 1031c269f196SRoland McGrath /* 1032c269f196SRoland McGrath * Some architectures need to do book-keeping after 1033c269f196SRoland McGrath * a ptrace attach. 1034c269f196SRoland McGrath */ 1035c269f196SRoland McGrath if (!ret) 1036c269f196SRoland McGrath arch_ptrace_attach(child); 1037c269f196SRoland McGrath goto out_put_task_struct; 1038c269f196SRoland McGrath } 1039c269f196SRoland McGrath 1040fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1041fca26f26STejun Heo request == PTRACE_INTERRUPT); 1042c269f196SRoland McGrath if (!ret) 1043c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 1044c269f196SRoland McGrath 1045c269f196SRoland McGrath out_put_task_struct: 1046c269f196SRoland McGrath put_task_struct(child); 1047c269f196SRoland McGrath out: 1048c269f196SRoland McGrath return ret; 1049c269f196SRoland McGrath } 105096b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1051bf26c018SFrederic Weisbecker 1052bf26c018SFrederic Weisbecker #ifdef CONFIG_HAVE_HW_BREAKPOINT 1053bf26c018SFrederic Weisbecker int ptrace_get_breakpoints(struct task_struct *tsk) 1054bf26c018SFrederic Weisbecker { 1055bf26c018SFrederic Weisbecker if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) 1056bf26c018SFrederic Weisbecker return 0; 1057bf26c018SFrederic Weisbecker 1058bf26c018SFrederic Weisbecker return -1; 1059bf26c018SFrederic Weisbecker } 1060bf26c018SFrederic Weisbecker 1061bf26c018SFrederic Weisbecker void ptrace_put_breakpoints(struct task_struct *tsk) 1062bf26c018SFrederic Weisbecker { 1063bf26c018SFrederic Weisbecker if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) 1064bf26c018SFrederic Weisbecker flush_ptrace_hw_breakpoint(tsk); 1065bf26c018SFrederic Weisbecker } 1066bf26c018SFrederic Weisbecker #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 1067