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 1259899d11fSOleg Nesterov /* Ensure that nothing can wake it up, even SIGKILL */ 1269899d11fSOleg Nesterov static bool ptrace_freeze_traced(struct task_struct *task) 1279899d11fSOleg Nesterov { 1289899d11fSOleg Nesterov bool ret = false; 1299899d11fSOleg Nesterov 1309899d11fSOleg Nesterov /* Lockless, nobody but us can set this flag */ 1319899d11fSOleg Nesterov if (task->jobctl & JOBCTL_LISTENING) 1329899d11fSOleg Nesterov return ret; 1339899d11fSOleg Nesterov 1349899d11fSOleg Nesterov spin_lock_irq(&task->sighand->siglock); 1359899d11fSOleg Nesterov if (task_is_traced(task) && !__fatal_signal_pending(task)) { 1369899d11fSOleg Nesterov task->state = __TASK_TRACED; 1379899d11fSOleg Nesterov ret = true; 1389899d11fSOleg Nesterov } 1399899d11fSOleg Nesterov spin_unlock_irq(&task->sighand->siglock); 1409899d11fSOleg Nesterov 1419899d11fSOleg Nesterov return ret; 1429899d11fSOleg Nesterov } 1439899d11fSOleg Nesterov 1449899d11fSOleg Nesterov static void ptrace_unfreeze_traced(struct task_struct *task) 1459899d11fSOleg Nesterov { 1469899d11fSOleg Nesterov if (task->state != __TASK_TRACED) 1479899d11fSOleg Nesterov return; 1489899d11fSOleg Nesterov 1499899d11fSOleg Nesterov WARN_ON(!task->ptrace || task->parent != current); 1509899d11fSOleg Nesterov 1519899d11fSOleg Nesterov spin_lock_irq(&task->sighand->siglock); 1529899d11fSOleg Nesterov if (__fatal_signal_pending(task)) 1539899d11fSOleg Nesterov wake_up_state(task, __TASK_TRACED); 1549899d11fSOleg Nesterov else 1559899d11fSOleg Nesterov task->state = TASK_TRACED; 1569899d11fSOleg Nesterov spin_unlock_irq(&task->sighand->siglock); 1579899d11fSOleg Nesterov } 1589899d11fSOleg Nesterov 159755e276bSTejun Heo /** 160755e276bSTejun Heo * ptrace_check_attach - check whether ptracee is ready for ptrace operation 161755e276bSTejun Heo * @child: ptracee to check for 162755e276bSTejun Heo * @ignore_state: don't check whether @child is currently %TASK_TRACED 163755e276bSTejun Heo * 164755e276bSTejun Heo * Check whether @child is being ptraced by %current and ready for further 165755e276bSTejun Heo * ptrace operations. If @ignore_state is %false, @child also should be in 166755e276bSTejun Heo * %TASK_TRACED state and on return the child is guaranteed to be traced 167755e276bSTejun Heo * and not executing. If @ignore_state is %true, @child can be in any 168755e276bSTejun Heo * state. 169755e276bSTejun Heo * 170755e276bSTejun Heo * CONTEXT: 171755e276bSTejun Heo * Grabs and releases tasklist_lock and @child->sighand->siglock. 172755e276bSTejun Heo * 173755e276bSTejun Heo * RETURNS: 174755e276bSTejun Heo * 0 on success, -ESRCH if %child is not ready. 1751da177e4SLinus Torvalds */ 176edea0d03SOleg Nesterov static int ptrace_check_attach(struct task_struct *child, bool ignore_state) 1771da177e4SLinus Torvalds { 1781da177e4SLinus Torvalds int ret = -ESRCH; 1791da177e4SLinus Torvalds 1801da177e4SLinus Torvalds /* 1811da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 1821da177e4SLinus Torvalds * possible race where someone else was tracing our child and 1831da177e4SLinus Torvalds * detached between these two checks. After this locked check, 1841da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 1851da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 1861da177e4SLinus Torvalds */ 1871da177e4SLinus Torvalds read_lock(&tasklist_lock); 1889899d11fSOleg Nesterov if (child->ptrace && child->parent == current) { 1899899d11fSOleg Nesterov WARN_ON(child->state == __TASK_TRACED); 190c0c0b649SOleg Nesterov /* 191c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 192c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 193c0c0b649SOleg Nesterov */ 1949899d11fSOleg Nesterov if (ignore_state || ptrace_freeze_traced(child)) 195321fb561SOleg Nesterov ret = 0; 1961da177e4SLinus Torvalds } 1971da177e4SLinus Torvalds read_unlock(&tasklist_lock); 1981da177e4SLinus Torvalds 1999899d11fSOleg Nesterov if (!ret && !ignore_state) { 2009899d11fSOleg Nesterov if (!wait_task_inactive(child, __TASK_TRACED)) { 2019899d11fSOleg Nesterov /* 2029899d11fSOleg Nesterov * This can only happen if may_ptrace_stop() fails and 2039899d11fSOleg Nesterov * ptrace_stop() changes ->state back to TASK_RUNNING, 2049899d11fSOleg Nesterov * so we should not worry about leaking __TASK_TRACED. 2059899d11fSOleg Nesterov */ 2069899d11fSOleg Nesterov WARN_ON(child->state == __TASK_TRACED); 2079899d11fSOleg Nesterov ret = -ESRCH; 2089899d11fSOleg Nesterov } 2099899d11fSOleg Nesterov } 2101da177e4SLinus Torvalds 2111da177e4SLinus Torvalds return ret; 2121da177e4SLinus Torvalds } 2131da177e4SLinus Torvalds 21469f594a3SEric Paris static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) 21569f594a3SEric Paris { 21669f594a3SEric Paris if (mode & PTRACE_MODE_NOAUDIT) 21769f594a3SEric Paris return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); 21869f594a3SEric Paris else 21969f594a3SEric Paris return has_ns_capability(current, ns, CAP_SYS_PTRACE); 22069f594a3SEric Paris } 22169f594a3SEric Paris 2229f99798fSTetsuo Handa /* Returns 0 on success, -errno on denial. */ 2239f99798fSTetsuo Handa static int __ptrace_may_access(struct task_struct *task, unsigned int mode) 224ab8d11beSMiklos Szeredi { 225c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 226b6dff3ecSDavid Howells 227df26c40eSEric W. Biederman /* May we inspect the given task? 228df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 229df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 230df26c40eSEric W. Biederman * 231df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 232df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 233df26c40eSEric W. Biederman * or halting the specified task is impossible. 234df26c40eSEric W. Biederman */ 235df26c40eSEric W. Biederman int dumpable = 0; 236df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 237df26c40eSEric W. Biederman if (task == current) 238df26c40eSEric W. Biederman return 0; 239c69e8d9cSDavid Howells rcu_read_lock(); 240c69e8d9cSDavid Howells tcred = __task_cred(task); 2415af66203SEric W. Biederman if (uid_eq(cred->uid, tcred->euid) && 2425af66203SEric W. Biederman uid_eq(cred->uid, tcred->suid) && 2435af66203SEric W. Biederman uid_eq(cred->uid, tcred->uid) && 2445af66203SEric W. Biederman gid_eq(cred->gid, tcred->egid) && 2455af66203SEric W. Biederman gid_eq(cred->gid, tcred->sgid) && 2465af66203SEric W. Biederman gid_eq(cred->gid, tcred->gid)) 2478409cca7SSerge E. Hallyn goto ok; 248c4a4d603SEric W. Biederman if (ptrace_has_cap(tcred->user_ns, mode)) 2498409cca7SSerge E. Hallyn goto ok; 250c69e8d9cSDavid Howells rcu_read_unlock(); 251ab8d11beSMiklos Szeredi return -EPERM; 2528409cca7SSerge E. Hallyn ok: 253c69e8d9cSDavid Howells rcu_read_unlock(); 254ab8d11beSMiklos Szeredi smp_rmb(); 255df26c40eSEric W. Biederman if (task->mm) 2566c5d5238SKawai, Hidehiro dumpable = get_dumpable(task->mm); 2574c44aaafSEric W. Biederman rcu_read_lock(); 2584c44aaafSEric W. Biederman if (!dumpable && !ptrace_has_cap(__task_cred(task)->user_ns, mode)) { 2594c44aaafSEric W. Biederman rcu_read_unlock(); 260ab8d11beSMiklos Szeredi return -EPERM; 2614c44aaafSEric W. Biederman } 2624c44aaafSEric W. Biederman rcu_read_unlock(); 263ab8d11beSMiklos Szeredi 2649e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 265ab8d11beSMiklos Szeredi } 266ab8d11beSMiklos Szeredi 267006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 268ab8d11beSMiklos Szeredi { 269ab8d11beSMiklos Szeredi int err; 270ab8d11beSMiklos Szeredi task_lock(task); 271006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 272ab8d11beSMiklos Szeredi task_unlock(task); 2733a709703SRoland McGrath return !err; 274ab8d11beSMiklos Szeredi } 275ab8d11beSMiklos Szeredi 2763544d72aSTejun Heo static int ptrace_attach(struct task_struct *task, long request, 277aa9147c9SDenys Vlasenko unsigned long addr, 2783544d72aSTejun Heo unsigned long flags) 2791da177e4SLinus Torvalds { 2803544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 2811da177e4SLinus Torvalds int retval; 282f5b40e36SLinus Torvalds 2833544d72aSTejun Heo retval = -EIO; 284aa9147c9SDenys Vlasenko if (seize) { 285aa9147c9SDenys Vlasenko if (addr != 0) 2863544d72aSTejun Heo goto out; 287aa9147c9SDenys Vlasenko if (flags & ~(unsigned long)PTRACE_O_MASK) 288aa9147c9SDenys Vlasenko goto out; 289aa9147c9SDenys Vlasenko flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); 290aa9147c9SDenys Vlasenko } else { 291aa9147c9SDenys Vlasenko flags = PT_PTRACED; 292aa9147c9SDenys Vlasenko } 2933544d72aSTejun Heo 294a5cb013dSAl Viro audit_ptrace(task); 295a5cb013dSAl Viro 2961da177e4SLinus Torvalds retval = -EPERM; 297b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 298b79b7ba9SOleg Nesterov goto out; 299bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 300f5b40e36SLinus Torvalds goto out; 301f5b40e36SLinus Torvalds 302f2f0b00aSOleg Nesterov /* 303f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 30486b6c1f3SDenys Vlasenko * SUID, SGID and LSM creds get determined differently 3055e751e99SDavid Howells * under ptrace. 306d84f4f99SDavid Howells */ 307793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 3089b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 309d84f4f99SDavid Howells goto out; 3104b105cbbSOleg Nesterov 311f5b40e36SLinus Torvalds task_lock(task); 312006ebb40SStephen Smalley retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); 3134b105cbbSOleg Nesterov task_unlock(task); 3141da177e4SLinus Torvalds if (retval) 3154b105cbbSOleg Nesterov goto unlock_creds; 3161da177e4SLinus Torvalds 3174b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 318b79b7ba9SOleg Nesterov retval = -EPERM; 319b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 3204b105cbbSOleg Nesterov goto unlock_tasklist; 321f2f0b00aSOleg Nesterov if (task->ptrace) 3224b105cbbSOleg Nesterov goto unlock_tasklist; 323b79b7ba9SOleg Nesterov 3243544d72aSTejun Heo if (seize) 325aa9147c9SDenys Vlasenko flags |= PT_SEIZED; 3264c44aaafSEric W. Biederman rcu_read_lock(); 3274c44aaafSEric W. Biederman if (ns_capable(__task_cred(task)->user_ns, CAP_SYS_PTRACE)) 328aa9147c9SDenys Vlasenko flags |= PT_PTRACE_CAP; 3294c44aaafSEric W. Biederman rcu_read_unlock(); 330aa9147c9SDenys Vlasenko task->ptrace = flags; 3311da177e4SLinus Torvalds 3321da177e4SLinus Torvalds __ptrace_link(task, current); 3333544d72aSTejun Heo 3343544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 3353544d72aSTejun Heo if (!seize) 33633e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 337b79b7ba9SOleg Nesterov 338d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 339d79fdd6dSTejun Heo 340d79fdd6dSTejun Heo /* 34173ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 342d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 343d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 344d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 345d79fdd6dSTejun Heo * for the transition to complete before returning from this 346d79fdd6dSTejun Heo * function. 347d79fdd6dSTejun Heo * 348d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 349d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 350d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 351d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 352d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 353d79fdd6dSTejun Heo * 354d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 355d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 356d79fdd6dSTejun Heo */ 3577dd3db54STejun Heo if (task_is_stopped(task) && 35873ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 359910ffdb1SOleg Nesterov signal_wake_up_state(task, __TASK_STOPPED); 360d79fdd6dSTejun Heo 361d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 362d79fdd6dSTejun Heo 363b79b7ba9SOleg Nesterov retval = 0; 3644b105cbbSOleg Nesterov unlock_tasklist: 3654b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3664b105cbbSOleg Nesterov unlock_creds: 3679b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 368f5b40e36SLinus Torvalds out: 369f701e5b7SVladimir Zapolskiy if (!retval) { 37062c124ffSTejun Heo wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, 37162c124ffSTejun Heo ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE); 372f701e5b7SVladimir Zapolskiy proc_ptrace_connector(task, PTRACE_ATTACH); 373f701e5b7SVladimir Zapolskiy } 374f701e5b7SVladimir Zapolskiy 3751da177e4SLinus Torvalds return retval; 3761da177e4SLinus Torvalds } 3771da177e4SLinus Torvalds 378f2f0b00aSOleg Nesterov /** 379f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 380f2f0b00aSOleg Nesterov * 381f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 382f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 383f2f0b00aSOleg Nesterov */ 384e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 385f2f0b00aSOleg Nesterov { 386f2f0b00aSOleg Nesterov int ret = -EPERM; 387f2f0b00aSOleg Nesterov 3884b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 3894b105cbbSOleg Nesterov /* Are we already being traced? */ 390f2f0b00aSOleg Nesterov if (!current->ptrace) { 391f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 392f2f0b00aSOleg Nesterov /* 393f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 394f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 395f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 396f2f0b00aSOleg Nesterov */ 397f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 398f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 399f2f0b00aSOleg Nesterov __ptrace_link(current, current->real_parent); 400f2f0b00aSOleg Nesterov } 401f2f0b00aSOleg Nesterov } 4024b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 4034b105cbbSOleg Nesterov 404f2f0b00aSOleg Nesterov return ret; 405f2f0b00aSOleg Nesterov } 406f2f0b00aSOleg Nesterov 40739c626aeSOleg Nesterov /* 40839c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 40939c626aeSOleg Nesterov */ 41039c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 41139c626aeSOleg Nesterov { 41239c626aeSOleg Nesterov int ret; 41339c626aeSOleg Nesterov spin_lock(&sigh->siglock); 41439c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 41539c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 41639c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 41739c626aeSOleg Nesterov return ret; 41839c626aeSOleg Nesterov } 41939c626aeSOleg Nesterov 42039c626aeSOleg Nesterov /* 42139c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 42239c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 42339c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 42439c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 42539c626aeSOleg Nesterov * 42639c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 42739c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 42839c626aeSOleg Nesterov * If it should reap itself, return true. 42939c626aeSOleg Nesterov * 430a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 431a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 432a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 433a7f0765eSOleg Nesterov * do_wait(). 43439c626aeSOleg Nesterov */ 43539c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 43639c626aeSOleg Nesterov { 4379843a1e9SOleg Nesterov bool dead; 4389843a1e9SOleg Nesterov 43939c626aeSOleg Nesterov __ptrace_unlink(p); 44039c626aeSOleg Nesterov 4419843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 4429843a1e9SOleg Nesterov return false; 4439843a1e9SOleg Nesterov 4449843a1e9SOleg Nesterov dead = !thread_group_leader(p); 4459843a1e9SOleg Nesterov 4469843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 44739c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 4489843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 449a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 450a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 4519843a1e9SOleg Nesterov dead = true; 45239c626aeSOleg Nesterov } 453a7f0765eSOleg Nesterov } 45439c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 4559843a1e9SOleg Nesterov if (dead) 45639c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 4579843a1e9SOleg Nesterov return dead; 45839c626aeSOleg Nesterov } 45939c626aeSOleg Nesterov 460e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 4611da177e4SLinus Torvalds { 46239c626aeSOleg Nesterov bool dead = false; 4634576145cSOleg Nesterov 4647ed20e1aSJesper Juhl if (!valid_signal(data)) 4651da177e4SLinus Torvalds return -EIO; 4661da177e4SLinus Torvalds 4671da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 4681da177e4SLinus Torvalds ptrace_disable(child); 4697d941432SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 4701da177e4SLinus Torvalds 47195c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 47239c626aeSOleg Nesterov /* 47339c626aeSOleg Nesterov * This child can be already killed. Make sure de_thread() or 47439c626aeSOleg Nesterov * our sub-thread doing do_wait() didn't do release_task() yet. 47539c626aeSOleg Nesterov */ 47695c3eb76SOleg Nesterov if (child->ptrace) { 47795c3eb76SOleg Nesterov child->exit_code = data; 4784576145cSOleg Nesterov dead = __ptrace_detach(current, child); 47995c3eb76SOleg Nesterov } 4801da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 4811da177e4SLinus Torvalds 482f701e5b7SVladimir Zapolskiy proc_ptrace_connector(child, PTRACE_DETACH); 4834576145cSOleg Nesterov if (unlikely(dead)) 4844576145cSOleg Nesterov release_task(child); 4854576145cSOleg Nesterov 4861da177e4SLinus Torvalds return 0; 4871da177e4SLinus Torvalds } 4881da177e4SLinus Torvalds 48939c626aeSOleg Nesterov /* 490c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 491c7e49c14SOleg Nesterov * for writing, and returns with it held too. But note it can release 492c7e49c14SOleg Nesterov * and reacquire the lock. 49339c626aeSOleg Nesterov */ 49439c626aeSOleg Nesterov void exit_ptrace(struct task_struct *tracer) 495c4b5ed25SNamhyung Kim __releases(&tasklist_lock) 496c4b5ed25SNamhyung Kim __acquires(&tasklist_lock) 49739c626aeSOleg Nesterov { 49839c626aeSOleg Nesterov struct task_struct *p, *n; 49939c626aeSOleg Nesterov LIST_HEAD(ptrace_dead); 50039c626aeSOleg Nesterov 501c7e49c14SOleg Nesterov if (likely(list_empty(&tracer->ptraced))) 502c7e49c14SOleg Nesterov return; 503c7e49c14SOleg Nesterov 50439c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 505992fb6e1SOleg Nesterov if (unlikely(p->ptrace & PT_EXITKILL)) 506992fb6e1SOleg Nesterov send_sig_info(SIGKILL, SEND_SIG_FORCED, p); 507992fb6e1SOleg Nesterov 50839c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 50939c626aeSOleg Nesterov list_add(&p->ptrace_entry, &ptrace_dead); 51039c626aeSOleg Nesterov } 51139c626aeSOleg Nesterov 512c7e49c14SOleg Nesterov write_unlock_irq(&tasklist_lock); 51339c626aeSOleg Nesterov BUG_ON(!list_empty(&tracer->ptraced)); 51439c626aeSOleg Nesterov 51539c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { 51639c626aeSOleg Nesterov list_del_init(&p->ptrace_entry); 51739c626aeSOleg Nesterov release_task(p); 51839c626aeSOleg Nesterov } 519c7e49c14SOleg Nesterov 520c7e49c14SOleg Nesterov write_lock_irq(&tasklist_lock); 52139c626aeSOleg Nesterov } 52239c626aeSOleg Nesterov 5231da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 5241da177e4SLinus Torvalds { 5251da177e4SLinus Torvalds int copied = 0; 5261da177e4SLinus Torvalds 5271da177e4SLinus Torvalds while (len > 0) { 5281da177e4SLinus Torvalds char buf[128]; 5291da177e4SLinus Torvalds int this_len, retval; 5301da177e4SLinus Torvalds 5311da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 5321da177e4SLinus Torvalds retval = access_process_vm(tsk, src, buf, this_len, 0); 5331da177e4SLinus Torvalds if (!retval) { 5341da177e4SLinus Torvalds if (copied) 5351da177e4SLinus Torvalds break; 5361da177e4SLinus Torvalds return -EIO; 5371da177e4SLinus Torvalds } 5381da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 5391da177e4SLinus Torvalds return -EFAULT; 5401da177e4SLinus Torvalds copied += retval; 5411da177e4SLinus Torvalds src += retval; 5421da177e4SLinus Torvalds dst += retval; 5431da177e4SLinus Torvalds len -= retval; 5441da177e4SLinus Torvalds } 5451da177e4SLinus Torvalds return copied; 5461da177e4SLinus Torvalds } 5471da177e4SLinus Torvalds 5481da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 5491da177e4SLinus Torvalds { 5501da177e4SLinus Torvalds int copied = 0; 5511da177e4SLinus Torvalds 5521da177e4SLinus Torvalds while (len > 0) { 5531da177e4SLinus Torvalds char buf[128]; 5541da177e4SLinus Torvalds int this_len, retval; 5551da177e4SLinus Torvalds 5561da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 5571da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 5581da177e4SLinus Torvalds return -EFAULT; 5591da177e4SLinus Torvalds retval = access_process_vm(tsk, dst, buf, this_len, 1); 5601da177e4SLinus Torvalds if (!retval) { 5611da177e4SLinus Torvalds if (copied) 5621da177e4SLinus Torvalds break; 5631da177e4SLinus Torvalds return -EIO; 5641da177e4SLinus Torvalds } 5651da177e4SLinus Torvalds copied += retval; 5661da177e4SLinus Torvalds src += retval; 5671da177e4SLinus Torvalds dst += retval; 5681da177e4SLinus Torvalds len -= retval; 5691da177e4SLinus Torvalds } 5701da177e4SLinus Torvalds return copied; 5711da177e4SLinus Torvalds } 5721da177e4SLinus Torvalds 5734abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 5741da177e4SLinus Torvalds { 57586b6c1f3SDenys Vlasenko unsigned flags; 57686b6c1f3SDenys Vlasenko 5778c5cf9e5SDenys Vlasenko if (data & ~(unsigned long)PTRACE_O_MASK) 5788c5cf9e5SDenys Vlasenko return -EINVAL; 5798c5cf9e5SDenys Vlasenko 58086b6c1f3SDenys Vlasenko /* Avoid intermediate state when all opts are cleared */ 58186b6c1f3SDenys Vlasenko flags = child->ptrace; 58286b6c1f3SDenys Vlasenko flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); 58386b6c1f3SDenys Vlasenko flags |= (data << PT_OPT_FLAG_SHIFT); 58486b6c1f3SDenys Vlasenko child->ptrace = flags; 5851da177e4SLinus Torvalds 5868c5cf9e5SDenys Vlasenko return 0; 5871da177e4SLinus Torvalds } 5881da177e4SLinus Torvalds 589e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 5901da177e4SLinus Torvalds { 591e4961254SOleg Nesterov unsigned long flags; 5921da177e4SLinus Torvalds int error = -ESRCH; 5931da177e4SLinus Torvalds 594e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5951da177e4SLinus Torvalds error = -EINVAL; 5961da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 597e16b2781SRoland McGrath *info = *child->last_siginfo; 5981da177e4SLinus Torvalds error = 0; 5991da177e4SLinus Torvalds } 600e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 6011da177e4SLinus Torvalds } 6021da177e4SLinus Torvalds return error; 6031da177e4SLinus Torvalds } 6041da177e4SLinus Torvalds 605e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 6061da177e4SLinus Torvalds { 607e4961254SOleg Nesterov unsigned long flags; 6081da177e4SLinus Torvalds int error = -ESRCH; 6091da177e4SLinus Torvalds 610e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 6111da177e4SLinus Torvalds error = -EINVAL; 6121da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 613e16b2781SRoland McGrath *child->last_siginfo = *info; 6141da177e4SLinus Torvalds error = 0; 6151da177e4SLinus Torvalds } 616e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 6171da177e4SLinus Torvalds } 6181da177e4SLinus Torvalds return error; 6191da177e4SLinus Torvalds } 6201da177e4SLinus Torvalds 62136df29d7SRoland McGrath 62236df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 62336df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 62436df29d7SRoland McGrath #else 62536df29d7SRoland McGrath #define is_singlestep(request) 0 62636df29d7SRoland McGrath #endif 62736df29d7SRoland McGrath 6285b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 6295b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 6305b88abbfSRoland McGrath #else 6315b88abbfSRoland McGrath #define is_singleblock(request) 0 6325b88abbfSRoland McGrath #endif 6335b88abbfSRoland McGrath 63436df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 63536df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 63636df29d7SRoland McGrath #else 63736df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 63836df29d7SRoland McGrath #endif 63936df29d7SRoland McGrath 6404abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 6414abf9869SNamhyung Kim unsigned long data) 64236df29d7SRoland McGrath { 64336df29d7SRoland McGrath if (!valid_signal(data)) 64436df29d7SRoland McGrath return -EIO; 64536df29d7SRoland McGrath 64636df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 64736df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 64836df29d7SRoland McGrath else 64936df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 65036df29d7SRoland McGrath 65136df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 65236df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 65336df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 65436df29d7SRoland McGrath else 65536df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 65636df29d7SRoland McGrath #endif 65736df29d7SRoland McGrath 6585b88abbfSRoland McGrath if (is_singleblock(request)) { 6595b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 6605b88abbfSRoland McGrath return -EIO; 6615b88abbfSRoland McGrath user_enable_block_step(child); 6625b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 66336df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 66436df29d7SRoland McGrath return -EIO; 66536df29d7SRoland McGrath user_enable_single_step(child); 6663a709703SRoland McGrath } else { 66736df29d7SRoland McGrath user_disable_single_step(child); 6683a709703SRoland McGrath } 66936df29d7SRoland McGrath 67036df29d7SRoland McGrath child->exit_code = data; 6710666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 67236df29d7SRoland McGrath 67336df29d7SRoland McGrath return 0; 67436df29d7SRoland McGrath } 67536df29d7SRoland McGrath 6762225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 6772225a122SSuresh Siddha 6782225a122SSuresh Siddha static const struct user_regset * 6792225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 6802225a122SSuresh Siddha { 6812225a122SSuresh Siddha const struct user_regset *regset; 6822225a122SSuresh Siddha int n; 6832225a122SSuresh Siddha 6842225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 6852225a122SSuresh Siddha regset = view->regsets + n; 6862225a122SSuresh Siddha if (regset->core_note_type == type) 6872225a122SSuresh Siddha return regset; 6882225a122SSuresh Siddha } 6892225a122SSuresh Siddha 6902225a122SSuresh Siddha return NULL; 6912225a122SSuresh Siddha } 6922225a122SSuresh Siddha 6932225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 6942225a122SSuresh Siddha struct iovec *kiov) 6952225a122SSuresh Siddha { 6962225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 6972225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 6982225a122SSuresh Siddha int regset_no; 6992225a122SSuresh Siddha 7002225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 701c6a0dd7eSSuresh Siddha return -EINVAL; 7022225a122SSuresh Siddha 7032225a122SSuresh Siddha regset_no = regset - view->regsets; 7042225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 7052225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 7062225a122SSuresh Siddha 7072225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 7082225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 7092225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 7102225a122SSuresh Siddha else 7112225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 7122225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 7132225a122SSuresh Siddha } 7142225a122SSuresh Siddha 715e8440c14SJosh Stone /* 716e8440c14SJosh Stone * This is declared in linux/regset.h and defined in machine-dependent 717e8440c14SJosh Stone * code. We put the export here, near the primary machine-neutral use, 718e8440c14SJosh Stone * to ensure no machine forgets it. 719e8440c14SJosh Stone */ 720e8440c14SJosh Stone EXPORT_SYMBOL_GPL(task_user_regset_view); 7212225a122SSuresh Siddha #endif 7222225a122SSuresh Siddha 7231da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 7244abf9869SNamhyung Kim unsigned long addr, unsigned long data) 7251da177e4SLinus Torvalds { 726fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 7271da177e4SLinus Torvalds int ret = -EIO; 728544b2c91STejun Heo siginfo_t siginfo, *si; 7299fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 7309fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 731fca26f26STejun Heo unsigned long flags; 7321da177e4SLinus Torvalds 7331da177e4SLinus Torvalds switch (request) { 73416c3e389SRoland McGrath case PTRACE_PEEKTEXT: 73516c3e389SRoland McGrath case PTRACE_PEEKDATA: 73616c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 73716c3e389SRoland McGrath case PTRACE_POKETEXT: 73816c3e389SRoland McGrath case PTRACE_POKEDATA: 73916c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 74016c3e389SRoland McGrath 7411da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 7421da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 7431da177e4SLinus Torvalds #endif 7441da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 7451da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 7461da177e4SLinus Torvalds break; 7471da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 7489fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 7491da177e4SLinus Torvalds break; 750e16b2781SRoland McGrath 7511da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 752e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 753e16b2781SRoland McGrath if (!ret) 7549fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 7551da177e4SLinus Torvalds break; 756e16b2781SRoland McGrath 7571da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 7589fed81dcSNamhyung Kim if (copy_from_user(&siginfo, datavp, sizeof siginfo)) 759e16b2781SRoland McGrath ret = -EFAULT; 760e16b2781SRoland McGrath else 761e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 7621da177e4SLinus Torvalds break; 763e16b2781SRoland McGrath 764fca26f26STejun Heo case PTRACE_INTERRUPT: 765fca26f26STejun Heo /* 766fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 767fca26f26STejun Heo * control. At least one trap is guaranteed to happen 768fca26f26STejun Heo * after this request. If @child is already trapped, the 769fca26f26STejun Heo * current trap is not disturbed and another trap will 770fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 771fca26f26STejun Heo * 772fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 773fca26f26STejun Heo * the pending condition is cleared regardless. 774fca26f26STejun Heo */ 775fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 776fca26f26STejun Heo break; 777fca26f26STejun Heo 778544b2c91STejun Heo /* 779544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 780544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 781544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 782544b2c91STejun Heo * tracee into STOP. 783544b2c91STejun Heo */ 784fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 785910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 786544b2c91STejun Heo 787544b2c91STejun Heo unlock_task_sighand(child, &flags); 788544b2c91STejun Heo ret = 0; 789544b2c91STejun Heo break; 790544b2c91STejun Heo 791544b2c91STejun Heo case PTRACE_LISTEN: 792544b2c91STejun Heo /* 793544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 794544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 795544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 796544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 797544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 798544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 799544b2c91STejun Heo */ 800544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 801544b2c91STejun Heo break; 802544b2c91STejun Heo 803544b2c91STejun Heo si = child->last_siginfo; 804f9d81f61SOleg Nesterov if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { 805544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 806544b2c91STejun Heo /* 807f9d81f61SOleg Nesterov * If NOTIFY is set, it means event happened between 808f9d81f61SOleg Nesterov * start of this trap and now. Trigger re-trap. 809544b2c91STejun Heo */ 810544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 811910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 812fca26f26STejun Heo ret = 0; 813f9d81f61SOleg Nesterov } 814f9d81f61SOleg Nesterov unlock_task_sighand(child, &flags); 815fca26f26STejun Heo break; 816fca26f26STejun Heo 8171bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 8181bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 8191bcf5482SAlexey Dobriyan break; 82036df29d7SRoland McGrath 8219c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 8229c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 823e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 8249c1a1259SMike Frysinger unsigned long tmp = 0; 8259c1a1259SMike Frysinger 826e0129ef9SOleg Nesterov ret = -ESRCH; 827e0129ef9SOleg Nesterov if (!mm) 828e0129ef9SOleg Nesterov break; 829e0129ef9SOleg Nesterov 8309c1a1259SMike Frysinger switch (addr) { 8319c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 832e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 8339c1a1259SMike Frysinger break; 8349c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 835e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 8369c1a1259SMike Frysinger break; 8379c1a1259SMike Frysinger default: 8389c1a1259SMike Frysinger break; 8399c1a1259SMike Frysinger } 840e0129ef9SOleg Nesterov mmput(mm); 8419c1a1259SMike Frysinger 8429fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 8439c1a1259SMike Frysinger break; 8449c1a1259SMike Frysinger } 8459c1a1259SMike Frysinger #endif 8469c1a1259SMike Frysinger 84736df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 84836df29d7SRoland McGrath case PTRACE_SINGLESTEP: 84936df29d7SRoland McGrath #endif 8505b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 8515b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 8525b88abbfSRoland McGrath #endif 85336df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 85436df29d7SRoland McGrath case PTRACE_SYSEMU: 85536df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 85636df29d7SRoland McGrath #endif 85736df29d7SRoland McGrath case PTRACE_SYSCALL: 85836df29d7SRoland McGrath case PTRACE_CONT: 85936df29d7SRoland McGrath return ptrace_resume(child, request, data); 86036df29d7SRoland McGrath 86136df29d7SRoland McGrath case PTRACE_KILL: 86236df29d7SRoland McGrath if (child->exit_state) /* already dead */ 86336df29d7SRoland McGrath return 0; 86436df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 86536df29d7SRoland McGrath 8662225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8672225a122SSuresh Siddha case PTRACE_GETREGSET: 8682225a122SSuresh Siddha case PTRACE_SETREGSET: 8692225a122SSuresh Siddha { 8702225a122SSuresh Siddha struct iovec kiov; 8719fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 8722225a122SSuresh Siddha 8732225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 8742225a122SSuresh Siddha return -EFAULT; 8752225a122SSuresh Siddha 8762225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 8772225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 8782225a122SSuresh Siddha return -EFAULT; 8792225a122SSuresh Siddha 8802225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 8812225a122SSuresh Siddha if (!ret) 8822225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 8832225a122SSuresh Siddha break; 8842225a122SSuresh Siddha } 8852225a122SSuresh Siddha #endif 8861da177e4SLinus Torvalds default: 8871da177e4SLinus Torvalds break; 8881da177e4SLinus Torvalds } 8891da177e4SLinus Torvalds 8901da177e4SLinus Torvalds return ret; 8911da177e4SLinus Torvalds } 892481bed45SChristoph Hellwig 8938053bdd5SOleg Nesterov static struct task_struct *ptrace_get_task_struct(pid_t pid) 8946b9c7ed8SChristoph Hellwig { 8956b9c7ed8SChristoph Hellwig struct task_struct *child; 8966b9c7ed8SChristoph Hellwig 8978053bdd5SOleg Nesterov rcu_read_lock(); 898228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 899481bed45SChristoph Hellwig if (child) 900481bed45SChristoph Hellwig get_task_struct(child); 9018053bdd5SOleg Nesterov rcu_read_unlock(); 902f400e198SSukadev Bhattiprolu 903481bed45SChristoph Hellwig if (!child) 9046b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 9056b9c7ed8SChristoph Hellwig return child; 906481bed45SChristoph Hellwig } 907481bed45SChristoph Hellwig 9080ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 9090ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 9100ac15559SChristoph Hellwig #endif 9110ac15559SChristoph Hellwig 9124abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 9134abf9869SNamhyung Kim unsigned long, data) 914481bed45SChristoph Hellwig { 915481bed45SChristoph Hellwig struct task_struct *child; 916481bed45SChristoph Hellwig long ret; 917481bed45SChristoph Hellwig 9186b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 9196b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 9206ea6dd93SHaavard Skinnemoen if (!ret) 9216ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 922481bed45SChristoph Hellwig goto out; 9236b9c7ed8SChristoph Hellwig } 9246b9c7ed8SChristoph Hellwig 9256b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 9266b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 9276b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 9286b9c7ed8SChristoph Hellwig goto out; 9296b9c7ed8SChristoph Hellwig } 930481bed45SChristoph Hellwig 9313544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 932aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 9330ac15559SChristoph Hellwig /* 9340ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 9350ac15559SChristoph Hellwig * a ptrace attach. 9360ac15559SChristoph Hellwig */ 9370ac15559SChristoph Hellwig if (!ret) 9380ac15559SChristoph Hellwig arch_ptrace_attach(child); 939005f18dfSChristoph Hellwig goto out_put_task_struct; 940481bed45SChristoph Hellwig } 941481bed45SChristoph Hellwig 942fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 943fca26f26STejun Heo request == PTRACE_INTERRUPT); 944481bed45SChristoph Hellwig if (ret < 0) 945481bed45SChristoph Hellwig goto out_put_task_struct; 946481bed45SChristoph Hellwig 947481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 9489899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 9499899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 950481bed45SChristoph Hellwig 951481bed45SChristoph Hellwig out_put_task_struct: 952481bed45SChristoph Hellwig put_task_struct(child); 953481bed45SChristoph Hellwig out: 954481bed45SChristoph Hellwig return ret; 955481bed45SChristoph Hellwig } 95676647323SAlexey Dobriyan 9574abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 9584abf9869SNamhyung Kim unsigned long data) 95976647323SAlexey Dobriyan { 96076647323SAlexey Dobriyan unsigned long tmp; 96176647323SAlexey Dobriyan int copied; 96276647323SAlexey Dobriyan 96376647323SAlexey Dobriyan copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); 96476647323SAlexey Dobriyan if (copied != sizeof(tmp)) 96576647323SAlexey Dobriyan return -EIO; 96676647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 96776647323SAlexey Dobriyan } 968f284ce72SAlexey Dobriyan 9694abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 9704abf9869SNamhyung Kim unsigned long data) 971f284ce72SAlexey Dobriyan { 972f284ce72SAlexey Dobriyan int copied; 973f284ce72SAlexey Dobriyan 974f284ce72SAlexey Dobriyan copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); 975f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 976f284ce72SAlexey Dobriyan } 977032d82d9SRoland McGrath 97896b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 979032d82d9SRoland McGrath #include <linux/compat.h> 980032d82d9SRoland McGrath 981032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 982032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 983032d82d9SRoland McGrath { 984032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 985032d82d9SRoland McGrath compat_ulong_t word; 986e16b2781SRoland McGrath siginfo_t siginfo; 987032d82d9SRoland McGrath int ret; 988032d82d9SRoland McGrath 989032d82d9SRoland McGrath switch (request) { 990032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 991032d82d9SRoland McGrath case PTRACE_PEEKDATA: 992032d82d9SRoland McGrath ret = access_process_vm(child, addr, &word, sizeof(word), 0); 993032d82d9SRoland McGrath if (ret != sizeof(word)) 994032d82d9SRoland McGrath ret = -EIO; 995032d82d9SRoland McGrath else 996032d82d9SRoland McGrath ret = put_user(word, datap); 997032d82d9SRoland McGrath break; 998032d82d9SRoland McGrath 999032d82d9SRoland McGrath case PTRACE_POKETEXT: 1000032d82d9SRoland McGrath case PTRACE_POKEDATA: 1001032d82d9SRoland McGrath ret = access_process_vm(child, addr, &data, sizeof(data), 1); 1002032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 1003032d82d9SRoland McGrath break; 1004032d82d9SRoland McGrath 1005032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 1006032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 1007032d82d9SRoland McGrath break; 1008032d82d9SRoland McGrath 1009e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 1010e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 1011e16b2781SRoland McGrath if (!ret) 1012e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 1013e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 1014e16b2781SRoland McGrath &siginfo); 1015e16b2781SRoland McGrath break; 1016e16b2781SRoland McGrath 1017e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 1018e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 1019e16b2781SRoland McGrath if (copy_siginfo_from_user32( 1020e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 1021e16b2781SRoland McGrath ret = -EFAULT; 1022e16b2781SRoland McGrath else 1023e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 1024e16b2781SRoland McGrath break; 10252225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 10262225a122SSuresh Siddha case PTRACE_GETREGSET: 10272225a122SSuresh Siddha case PTRACE_SETREGSET: 10282225a122SSuresh Siddha { 10292225a122SSuresh Siddha struct iovec kiov; 10302225a122SSuresh Siddha struct compat_iovec __user *uiov = 10312225a122SSuresh Siddha (struct compat_iovec __user *) datap; 10322225a122SSuresh Siddha compat_uptr_t ptr; 10332225a122SSuresh Siddha compat_size_t len; 10342225a122SSuresh Siddha 10352225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 10362225a122SSuresh Siddha return -EFAULT; 10372225a122SSuresh Siddha 10382225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 10392225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 10402225a122SSuresh Siddha return -EFAULT; 10412225a122SSuresh Siddha 10422225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 10432225a122SSuresh Siddha kiov.iov_len = len; 10442225a122SSuresh Siddha 10452225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 10462225a122SSuresh Siddha if (!ret) 10472225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 10482225a122SSuresh Siddha break; 10492225a122SSuresh Siddha } 10502225a122SSuresh Siddha #endif 1051e16b2781SRoland McGrath 1052032d82d9SRoland McGrath default: 1053032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 1054032d82d9SRoland McGrath } 1055032d82d9SRoland McGrath 1056032d82d9SRoland McGrath return ret; 1057032d82d9SRoland McGrath } 1058c269f196SRoland McGrath 1059c269f196SRoland McGrath asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, 1060c269f196SRoland McGrath compat_long_t addr, compat_long_t data) 1061c269f196SRoland McGrath { 1062c269f196SRoland McGrath struct task_struct *child; 1063c269f196SRoland McGrath long ret; 1064c269f196SRoland McGrath 1065c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1066c269f196SRoland McGrath ret = ptrace_traceme(); 1067c269f196SRoland McGrath goto out; 1068c269f196SRoland McGrath } 1069c269f196SRoland McGrath 1070c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 1071c269f196SRoland McGrath if (IS_ERR(child)) { 1072c269f196SRoland McGrath ret = PTR_ERR(child); 1073c269f196SRoland McGrath goto out; 1074c269f196SRoland McGrath } 1075c269f196SRoland McGrath 10763544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1077aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 1078c269f196SRoland McGrath /* 1079c269f196SRoland McGrath * Some architectures need to do book-keeping after 1080c269f196SRoland McGrath * a ptrace attach. 1081c269f196SRoland McGrath */ 1082c269f196SRoland McGrath if (!ret) 1083c269f196SRoland McGrath arch_ptrace_attach(child); 1084c269f196SRoland McGrath goto out_put_task_struct; 1085c269f196SRoland McGrath } 1086c269f196SRoland McGrath 1087fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1088fca26f26STejun Heo request == PTRACE_INTERRUPT); 10899899d11fSOleg Nesterov if (!ret) { 1090c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 10919899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 10929899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 10939899d11fSOleg Nesterov } 1094c269f196SRoland McGrath 1095c269f196SRoland McGrath out_put_task_struct: 1096c269f196SRoland McGrath put_task_struct(child); 1097c269f196SRoland McGrath out: 1098c269f196SRoland McGrath return ret; 1099c269f196SRoland McGrath } 110096b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1101bf26c018SFrederic Weisbecker 1102bf26c018SFrederic Weisbecker #ifdef CONFIG_HAVE_HW_BREAKPOINT 1103bf26c018SFrederic Weisbecker int ptrace_get_breakpoints(struct task_struct *tsk) 1104bf26c018SFrederic Weisbecker { 1105bf26c018SFrederic Weisbecker if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) 1106bf26c018SFrederic Weisbecker return 0; 1107bf26c018SFrederic Weisbecker 1108bf26c018SFrederic Weisbecker return -1; 1109bf26c018SFrederic Weisbecker } 1110bf26c018SFrederic Weisbecker 1111bf26c018SFrederic Weisbecker void ptrace_put_breakpoints(struct task_struct *tsk) 1112bf26c018SFrederic Weisbecker { 1113bf26c018SFrederic Weisbecker if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) 1114bf26c018SFrederic Weisbecker flush_ptrace_hw_breakpoint(tsk); 1115bf26c018SFrederic Weisbecker } 1116bf26c018SFrederic Weisbecker #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 1117