11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/kernel/ptrace.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * (C) Copyright 1999 Linus Torvalds 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * Common interfaces for "ptrace()" which we do not want 71da177e4SLinus Torvalds * to continually duplicate across every architecture. 81da177e4SLinus Torvalds */ 91da177e4SLinus Torvalds 10c59ede7bSRandy.Dunlap #include <linux/capability.h> 111da177e4SLinus Torvalds #include <linux/module.h> 121da177e4SLinus Torvalds #include <linux/sched.h> 131da177e4SLinus Torvalds #include <linux/errno.h> 141da177e4SLinus Torvalds #include <linux/mm.h> 151da177e4SLinus Torvalds #include <linux/highmem.h> 161da177e4SLinus Torvalds #include <linux/pagemap.h> 171da177e4SLinus Torvalds #include <linux/ptrace.h> 181da177e4SLinus Torvalds #include <linux/security.h> 197ed20e1aSJesper Juhl #include <linux/signal.h> 20a5cb013dSAl Viro #include <linux/audit.h> 21b488893aSPavel Emelyanov #include <linux/pid_namespace.h> 22f17d30a8SAdrian Bunk #include <linux/syscalls.h> 233a709703SRoland McGrath #include <linux/uaccess.h> 242225a122SSuresh Siddha #include <linux/regset.h> 25bf26c018SFrederic Weisbecker #include <linux/hw_breakpoint.h> 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 || 990e9f0a4aSTejun Heo child->signal->group_stop_count)) 100a8f072c1STejun Heo child->jobctl |= JOBCTL_STOP_PENDING; 1010e9f0a4aSTejun Heo 1020e9f0a4aSTejun Heo /* 1030e9f0a4aSTejun Heo * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick 1040e9f0a4aSTejun Heo * @child in the butt. Note that @resume should be used iff @child 1050e9f0a4aSTejun Heo * is in TASK_TRACED; otherwise, we might unduly disrupt 1060e9f0a4aSTejun Heo * TASK_KILLABLE sleeps. 1070e9f0a4aSTejun Heo */ 108a8f072c1STejun Heo if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) 1090e9f0a4aSTejun Heo signal_wake_up(child, task_is_traced(child)); 1100e9f0a4aSTejun Heo 1111da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 1121da177e4SLinus Torvalds } 1131da177e4SLinus Torvalds 114755e276bSTejun Heo /** 115755e276bSTejun Heo * ptrace_check_attach - check whether ptracee is ready for ptrace operation 116755e276bSTejun Heo * @child: ptracee to check for 117755e276bSTejun Heo * @ignore_state: don't check whether @child is currently %TASK_TRACED 118755e276bSTejun Heo * 119755e276bSTejun Heo * Check whether @child is being ptraced by %current and ready for further 120755e276bSTejun Heo * ptrace operations. If @ignore_state is %false, @child also should be in 121755e276bSTejun Heo * %TASK_TRACED state and on return the child is guaranteed to be traced 122755e276bSTejun Heo * and not executing. If @ignore_state is %true, @child can be in any 123755e276bSTejun Heo * state. 124755e276bSTejun Heo * 125755e276bSTejun Heo * CONTEXT: 126755e276bSTejun Heo * Grabs and releases tasklist_lock and @child->sighand->siglock. 127755e276bSTejun Heo * 128755e276bSTejun Heo * RETURNS: 129755e276bSTejun Heo * 0 on success, -ESRCH if %child is not ready. 1301da177e4SLinus Torvalds */ 131755e276bSTejun Heo int ptrace_check_attach(struct task_struct *child, bool ignore_state) 1321da177e4SLinus Torvalds { 1331da177e4SLinus Torvalds int ret = -ESRCH; 1341da177e4SLinus Torvalds 1351da177e4SLinus Torvalds /* 1361da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 1371da177e4SLinus Torvalds * possible race where someone else was tracing our child and 1381da177e4SLinus Torvalds * detached between these two checks. After this locked check, 1391da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 1401da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 1411da177e4SLinus Torvalds */ 1421da177e4SLinus Torvalds read_lock(&tasklist_lock); 143c0c0b649SOleg Nesterov if ((child->ptrace & PT_PTRACED) && child->parent == current) { 144c0c0b649SOleg Nesterov /* 145c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 146c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 147c0c0b649SOleg Nesterov */ 1481da177e4SLinus Torvalds spin_lock_irq(&child->sighand->siglock); 149321fb561SOleg Nesterov WARN_ON_ONCE(task_is_stopped(child)); 150544b2c91STejun Heo if (ignore_state || (task_is_traced(child) && 151544b2c91STejun Heo !(child->jobctl & JOBCTL_LISTENING))) 152321fb561SOleg Nesterov ret = 0; 1531da177e4SLinus Torvalds spin_unlock_irq(&child->sighand->siglock); 1541da177e4SLinus Torvalds } 1551da177e4SLinus Torvalds read_unlock(&tasklist_lock); 1561da177e4SLinus Torvalds 157755e276bSTejun Heo if (!ret && !ignore_state) 15885ba2d86SRoland McGrath ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; 1591da177e4SLinus Torvalds 1601da177e4SLinus Torvalds /* All systems go.. */ 1611da177e4SLinus Torvalds return ret; 1621da177e4SLinus Torvalds } 1631da177e4SLinus Torvalds 164006ebb40SStephen Smalley int __ptrace_may_access(struct task_struct *task, unsigned int mode) 165ab8d11beSMiklos Szeredi { 166c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 167b6dff3ecSDavid Howells 168df26c40eSEric W. Biederman /* May we inspect the given task? 169df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 170df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 171df26c40eSEric W. Biederman * 172df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 173df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 174df26c40eSEric W. Biederman * or halting the specified task is impossible. 175df26c40eSEric W. Biederman */ 176df26c40eSEric W. Biederman int dumpable = 0; 177df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 178df26c40eSEric W. Biederman if (task == current) 179df26c40eSEric W. Biederman return 0; 180c69e8d9cSDavid Howells rcu_read_lock(); 181c69e8d9cSDavid Howells tcred = __task_cred(task); 1828409cca7SSerge E. Hallyn if (cred->user->user_ns == tcred->user->user_ns && 1838409cca7SSerge E. Hallyn (cred->uid == tcred->euid && 1848409cca7SSerge E. Hallyn cred->uid == tcred->suid && 1858409cca7SSerge E. Hallyn cred->uid == tcred->uid && 1868409cca7SSerge E. Hallyn cred->gid == tcred->egid && 1878409cca7SSerge E. Hallyn cred->gid == tcred->sgid && 1888409cca7SSerge E. Hallyn cred->gid == tcred->gid)) 1898409cca7SSerge E. Hallyn goto ok; 1908409cca7SSerge E. Hallyn if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE)) 1918409cca7SSerge E. Hallyn goto ok; 192c69e8d9cSDavid Howells rcu_read_unlock(); 193ab8d11beSMiklos Szeredi return -EPERM; 1948409cca7SSerge E. Hallyn ok: 195c69e8d9cSDavid Howells rcu_read_unlock(); 196ab8d11beSMiklos Szeredi smp_rmb(); 197df26c40eSEric W. Biederman if (task->mm) 1986c5d5238SKawai, Hidehiro dumpable = get_dumpable(task->mm); 1998409cca7SSerge E. Hallyn if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE)) 200ab8d11beSMiklos Szeredi return -EPERM; 201ab8d11beSMiklos Szeredi 2029e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 203ab8d11beSMiklos Szeredi } 204ab8d11beSMiklos Szeredi 205006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 206ab8d11beSMiklos Szeredi { 207ab8d11beSMiklos Szeredi int err; 208ab8d11beSMiklos Szeredi task_lock(task); 209006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 210ab8d11beSMiklos Szeredi task_unlock(task); 2113a709703SRoland McGrath return !err; 212ab8d11beSMiklos Szeredi } 213ab8d11beSMiklos Szeredi 2143544d72aSTejun Heo static int ptrace_attach(struct task_struct *task, long request, 2153544d72aSTejun Heo unsigned long flags) 2161da177e4SLinus Torvalds { 2173544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 2181da177e4SLinus Torvalds int retval; 219f5b40e36SLinus Torvalds 2203544d72aSTejun Heo /* 2213544d72aSTejun Heo * SEIZE will enable new ptrace behaviors which will be implemented 2223544d72aSTejun Heo * gradually. SEIZE_DEVEL is used to prevent applications 2233544d72aSTejun Heo * expecting full SEIZE behaviors trapping on kernel commits which 2243544d72aSTejun Heo * are still in the process of implementing them. 2253544d72aSTejun Heo * 2263544d72aSTejun Heo * Only test programs for new ptrace behaviors being implemented 2273544d72aSTejun Heo * should set SEIZE_DEVEL. If unset, SEIZE will fail with -EIO. 2283544d72aSTejun Heo * 2293544d72aSTejun Heo * Once SEIZE behaviors are completely implemented, this flag and 2303544d72aSTejun Heo * the following test will be removed. 2313544d72aSTejun Heo */ 2323544d72aSTejun Heo retval = -EIO; 2333544d72aSTejun Heo if (seize && !(flags & PTRACE_SEIZE_DEVEL)) 2343544d72aSTejun Heo goto out; 2353544d72aSTejun Heo 236a5cb013dSAl Viro audit_ptrace(task); 237a5cb013dSAl Viro 2381da177e4SLinus Torvalds retval = -EPERM; 239b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 240b79b7ba9SOleg Nesterov goto out; 241bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 242f5b40e36SLinus Torvalds goto out; 243f5b40e36SLinus Torvalds 244f2f0b00aSOleg Nesterov /* 245f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 2465e751e99SDavid Howells * interference; SUID, SGID and LSM creds get determined differently 2475e751e99SDavid Howells * under ptrace. 248d84f4f99SDavid Howells */ 249793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 2509b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 251d84f4f99SDavid Howells goto out; 2524b105cbbSOleg Nesterov 253f5b40e36SLinus Torvalds task_lock(task); 254006ebb40SStephen Smalley retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); 2554b105cbbSOleg Nesterov task_unlock(task); 2561da177e4SLinus Torvalds if (retval) 2574b105cbbSOleg Nesterov goto unlock_creds; 2581da177e4SLinus Torvalds 2594b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 260b79b7ba9SOleg Nesterov retval = -EPERM; 261b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 2624b105cbbSOleg Nesterov goto unlock_tasklist; 263f2f0b00aSOleg Nesterov if (task->ptrace) 2644b105cbbSOleg Nesterov goto unlock_tasklist; 265b79b7ba9SOleg Nesterov 266f2f0b00aSOleg Nesterov task->ptrace = PT_PTRACED; 2673544d72aSTejun Heo if (seize) 2683544d72aSTejun Heo task->ptrace |= PT_SEIZED; 2698409cca7SSerge E. Hallyn if (task_ns_capable(task, CAP_SYS_PTRACE)) 2701da177e4SLinus Torvalds task->ptrace |= PT_PTRACE_CAP; 2711da177e4SLinus Torvalds 2721da177e4SLinus Torvalds __ptrace_link(task, current); 2733544d72aSTejun Heo 2743544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 2753544d72aSTejun Heo if (!seize) 27633e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 277b79b7ba9SOleg Nesterov 278d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 279d79fdd6dSTejun Heo 280d79fdd6dSTejun Heo /* 28173ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 282d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 283d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 284d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 285d79fdd6dSTejun Heo * for the transition to complete before returning from this 286d79fdd6dSTejun Heo * function. 287d79fdd6dSTejun Heo * 288d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 289d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 290d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 291d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 292d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 293d79fdd6dSTejun Heo * 294d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 295d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 296d79fdd6dSTejun Heo */ 2977dd3db54STejun Heo if (task_is_stopped(task) && 29873ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 299d79fdd6dSTejun Heo signal_wake_up(task, 1); 300d79fdd6dSTejun Heo 301d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 302d79fdd6dSTejun Heo 303b79b7ba9SOleg Nesterov retval = 0; 3044b105cbbSOleg Nesterov unlock_tasklist: 3054b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3064b105cbbSOleg Nesterov unlock_creds: 3079b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 308f5b40e36SLinus Torvalds out: 309f701e5b7SVladimir Zapolskiy if (!retval) { 31062c124ffSTejun Heo wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, 31162c124ffSTejun Heo ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE); 312f701e5b7SVladimir Zapolskiy proc_ptrace_connector(task, PTRACE_ATTACH); 313f701e5b7SVladimir Zapolskiy } 314f701e5b7SVladimir Zapolskiy 3151da177e4SLinus Torvalds return retval; 3161da177e4SLinus Torvalds } 3171da177e4SLinus Torvalds 318f2f0b00aSOleg Nesterov /** 319f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 320f2f0b00aSOleg Nesterov * 321f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 322f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 323f2f0b00aSOleg Nesterov */ 324e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 325f2f0b00aSOleg Nesterov { 326f2f0b00aSOleg Nesterov int ret = -EPERM; 327f2f0b00aSOleg Nesterov 3284b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 3294b105cbbSOleg Nesterov /* Are we already being traced? */ 330f2f0b00aSOleg Nesterov if (!current->ptrace) { 331f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 332f2f0b00aSOleg Nesterov /* 333f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 334f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 335f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 336f2f0b00aSOleg Nesterov */ 337f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 338f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 339f2f0b00aSOleg Nesterov __ptrace_link(current, current->real_parent); 340f2f0b00aSOleg Nesterov } 341f2f0b00aSOleg Nesterov } 3424b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3434b105cbbSOleg Nesterov 344f2f0b00aSOleg Nesterov return ret; 345f2f0b00aSOleg Nesterov } 346f2f0b00aSOleg Nesterov 34739c626aeSOleg Nesterov /* 34839c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 34939c626aeSOleg Nesterov */ 35039c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 35139c626aeSOleg Nesterov { 35239c626aeSOleg Nesterov int ret; 35339c626aeSOleg Nesterov spin_lock(&sigh->siglock); 35439c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 35539c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 35639c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 35739c626aeSOleg Nesterov return ret; 35839c626aeSOleg Nesterov } 35939c626aeSOleg Nesterov 36039c626aeSOleg Nesterov /* 36139c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 36239c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 36339c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 36439c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 36539c626aeSOleg Nesterov * 36639c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 36739c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 36839c626aeSOleg Nesterov * If it should reap itself, return true. 36939c626aeSOleg Nesterov * 370a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 371a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 372a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 373a7f0765eSOleg Nesterov * do_wait(). 37439c626aeSOleg Nesterov */ 37539c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 37639c626aeSOleg Nesterov { 3779843a1e9SOleg Nesterov bool dead; 3789843a1e9SOleg Nesterov 37939c626aeSOleg Nesterov __ptrace_unlink(p); 38039c626aeSOleg Nesterov 3819843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 3829843a1e9SOleg Nesterov return false; 3839843a1e9SOleg Nesterov 3849843a1e9SOleg Nesterov dead = !thread_group_leader(p); 3859843a1e9SOleg Nesterov 3869843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 38739c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 3889843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 389a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 390a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 3919843a1e9SOleg Nesterov dead = true; 39239c626aeSOleg Nesterov } 393a7f0765eSOleg Nesterov } 39439c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 3959843a1e9SOleg Nesterov if (dead) 39639c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 3979843a1e9SOleg Nesterov return dead; 39839c626aeSOleg Nesterov } 39939c626aeSOleg Nesterov 400e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 4011da177e4SLinus Torvalds { 40239c626aeSOleg Nesterov bool dead = false; 4034576145cSOleg Nesterov 4047ed20e1aSJesper Juhl if (!valid_signal(data)) 4051da177e4SLinus Torvalds return -EIO; 4061da177e4SLinus Torvalds 4071da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 4081da177e4SLinus Torvalds ptrace_disable(child); 4097d941432SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 4101da177e4SLinus Torvalds 41195c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 41239c626aeSOleg Nesterov /* 41339c626aeSOleg Nesterov * This child can be already killed. Make sure de_thread() or 41439c626aeSOleg Nesterov * our sub-thread doing do_wait() didn't do release_task() yet. 41539c626aeSOleg Nesterov */ 41695c3eb76SOleg Nesterov if (child->ptrace) { 41795c3eb76SOleg Nesterov child->exit_code = data; 4184576145cSOleg Nesterov dead = __ptrace_detach(current, child); 41995c3eb76SOleg Nesterov } 4201da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 4211da177e4SLinus Torvalds 422f701e5b7SVladimir Zapolskiy proc_ptrace_connector(child, PTRACE_DETACH); 4234576145cSOleg Nesterov if (unlikely(dead)) 4244576145cSOleg Nesterov release_task(child); 4254576145cSOleg Nesterov 4261da177e4SLinus Torvalds return 0; 4271da177e4SLinus Torvalds } 4281da177e4SLinus Torvalds 42939c626aeSOleg Nesterov /* 430c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 431c7e49c14SOleg Nesterov * for writing, and returns with it held too. But note it can release 432c7e49c14SOleg Nesterov * and reacquire the lock. 43339c626aeSOleg Nesterov */ 43439c626aeSOleg Nesterov void exit_ptrace(struct task_struct *tracer) 435c4b5ed25SNamhyung Kim __releases(&tasklist_lock) 436c4b5ed25SNamhyung Kim __acquires(&tasklist_lock) 43739c626aeSOleg Nesterov { 43839c626aeSOleg Nesterov struct task_struct *p, *n; 43939c626aeSOleg Nesterov LIST_HEAD(ptrace_dead); 44039c626aeSOleg Nesterov 441c7e49c14SOleg Nesterov if (likely(list_empty(&tracer->ptraced))) 442c7e49c14SOleg Nesterov return; 443c7e49c14SOleg Nesterov 44439c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 44539c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 44639c626aeSOleg Nesterov list_add(&p->ptrace_entry, &ptrace_dead); 44739c626aeSOleg Nesterov } 44839c626aeSOleg Nesterov 449c7e49c14SOleg Nesterov write_unlock_irq(&tasklist_lock); 45039c626aeSOleg Nesterov BUG_ON(!list_empty(&tracer->ptraced)); 45139c626aeSOleg Nesterov 45239c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { 45339c626aeSOleg Nesterov list_del_init(&p->ptrace_entry); 45439c626aeSOleg Nesterov release_task(p); 45539c626aeSOleg Nesterov } 456c7e49c14SOleg Nesterov 457c7e49c14SOleg Nesterov write_lock_irq(&tasklist_lock); 45839c626aeSOleg Nesterov } 45939c626aeSOleg Nesterov 4601da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 4611da177e4SLinus Torvalds { 4621da177e4SLinus Torvalds int copied = 0; 4631da177e4SLinus Torvalds 4641da177e4SLinus Torvalds while (len > 0) { 4651da177e4SLinus Torvalds char buf[128]; 4661da177e4SLinus Torvalds int this_len, retval; 4671da177e4SLinus Torvalds 4681da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4691da177e4SLinus Torvalds retval = access_process_vm(tsk, src, buf, this_len, 0); 4701da177e4SLinus Torvalds if (!retval) { 4711da177e4SLinus Torvalds if (copied) 4721da177e4SLinus Torvalds break; 4731da177e4SLinus Torvalds return -EIO; 4741da177e4SLinus Torvalds } 4751da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 4761da177e4SLinus Torvalds return -EFAULT; 4771da177e4SLinus Torvalds copied += retval; 4781da177e4SLinus Torvalds src += retval; 4791da177e4SLinus Torvalds dst += retval; 4801da177e4SLinus Torvalds len -= retval; 4811da177e4SLinus Torvalds } 4821da177e4SLinus Torvalds return copied; 4831da177e4SLinus Torvalds } 4841da177e4SLinus Torvalds 4851da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 4861da177e4SLinus Torvalds { 4871da177e4SLinus Torvalds int copied = 0; 4881da177e4SLinus Torvalds 4891da177e4SLinus Torvalds while (len > 0) { 4901da177e4SLinus Torvalds char buf[128]; 4911da177e4SLinus Torvalds int this_len, retval; 4921da177e4SLinus Torvalds 4931da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4941da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 4951da177e4SLinus Torvalds return -EFAULT; 4961da177e4SLinus Torvalds retval = access_process_vm(tsk, dst, buf, this_len, 1); 4971da177e4SLinus Torvalds if (!retval) { 4981da177e4SLinus Torvalds if (copied) 4991da177e4SLinus Torvalds break; 5001da177e4SLinus Torvalds return -EIO; 5011da177e4SLinus Torvalds } 5021da177e4SLinus Torvalds copied += retval; 5031da177e4SLinus Torvalds src += retval; 5041da177e4SLinus Torvalds dst += retval; 5051da177e4SLinus Torvalds len -= retval; 5061da177e4SLinus Torvalds } 5071da177e4SLinus Torvalds return copied; 5081da177e4SLinus Torvalds } 5091da177e4SLinus Torvalds 5104abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 5111da177e4SLinus Torvalds { 5121da177e4SLinus Torvalds child->ptrace &= ~PT_TRACE_MASK; 5131da177e4SLinus Torvalds 5141da177e4SLinus Torvalds if (data & PTRACE_O_TRACESYSGOOD) 5151da177e4SLinus Torvalds child->ptrace |= PT_TRACESYSGOOD; 5161da177e4SLinus Torvalds 5171da177e4SLinus Torvalds if (data & PTRACE_O_TRACEFORK) 5181da177e4SLinus Torvalds child->ptrace |= PT_TRACE_FORK; 5191da177e4SLinus Torvalds 5201da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORK) 5211da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK; 5221da177e4SLinus Torvalds 5231da177e4SLinus Torvalds if (data & PTRACE_O_TRACECLONE) 5241da177e4SLinus Torvalds child->ptrace |= PT_TRACE_CLONE; 5251da177e4SLinus Torvalds 5261da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXEC) 5271da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXEC; 5281da177e4SLinus Torvalds 5291da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORKDONE) 5301da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK_DONE; 5311da177e4SLinus Torvalds 5321da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXIT) 5331da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXIT; 5341da177e4SLinus Torvalds 5351da177e4SLinus Torvalds return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; 5361da177e4SLinus Torvalds } 5371da177e4SLinus Torvalds 538e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 5391da177e4SLinus Torvalds { 540e4961254SOleg Nesterov unsigned long flags; 5411da177e4SLinus Torvalds int error = -ESRCH; 5421da177e4SLinus Torvalds 543e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5441da177e4SLinus Torvalds error = -EINVAL; 5451da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 546e16b2781SRoland McGrath *info = *child->last_siginfo; 5471da177e4SLinus Torvalds error = 0; 5481da177e4SLinus Torvalds } 549e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5501da177e4SLinus Torvalds } 5511da177e4SLinus Torvalds return error; 5521da177e4SLinus Torvalds } 5531da177e4SLinus Torvalds 554e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 5551da177e4SLinus Torvalds { 556e4961254SOleg Nesterov unsigned long flags; 5571da177e4SLinus Torvalds int error = -ESRCH; 5581da177e4SLinus Torvalds 559e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5601da177e4SLinus Torvalds error = -EINVAL; 5611da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 562e16b2781SRoland McGrath *child->last_siginfo = *info; 5631da177e4SLinus Torvalds error = 0; 5641da177e4SLinus Torvalds } 565e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5661da177e4SLinus Torvalds } 5671da177e4SLinus Torvalds return error; 5681da177e4SLinus Torvalds } 5691da177e4SLinus Torvalds 57036df29d7SRoland McGrath 57136df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 57236df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 57336df29d7SRoland McGrath #else 57436df29d7SRoland McGrath #define is_singlestep(request) 0 57536df29d7SRoland McGrath #endif 57636df29d7SRoland McGrath 5775b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 5785b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 5795b88abbfSRoland McGrath #else 5805b88abbfSRoland McGrath #define is_singleblock(request) 0 5815b88abbfSRoland McGrath #endif 5825b88abbfSRoland McGrath 58336df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 58436df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 58536df29d7SRoland McGrath #else 58636df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 58736df29d7SRoland McGrath #endif 58836df29d7SRoland McGrath 5894abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 5904abf9869SNamhyung Kim unsigned long data) 59136df29d7SRoland McGrath { 59236df29d7SRoland McGrath if (!valid_signal(data)) 59336df29d7SRoland McGrath return -EIO; 59436df29d7SRoland McGrath 59536df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 59636df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 59736df29d7SRoland McGrath else 59836df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 59936df29d7SRoland McGrath 60036df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 60136df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 60236df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 60336df29d7SRoland McGrath else 60436df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 60536df29d7SRoland McGrath #endif 60636df29d7SRoland McGrath 6075b88abbfSRoland McGrath if (is_singleblock(request)) { 6085b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 6095b88abbfSRoland McGrath return -EIO; 6105b88abbfSRoland McGrath user_enable_block_step(child); 6115b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 61236df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 61336df29d7SRoland McGrath return -EIO; 61436df29d7SRoland McGrath user_enable_single_step(child); 6153a709703SRoland McGrath } else { 61636df29d7SRoland McGrath user_disable_single_step(child); 6173a709703SRoland McGrath } 61836df29d7SRoland McGrath 61936df29d7SRoland McGrath child->exit_code = data; 6200666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 62136df29d7SRoland McGrath 62236df29d7SRoland McGrath return 0; 62336df29d7SRoland McGrath } 62436df29d7SRoland McGrath 6252225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 6262225a122SSuresh Siddha 6272225a122SSuresh Siddha static const struct user_regset * 6282225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 6292225a122SSuresh Siddha { 6302225a122SSuresh Siddha const struct user_regset *regset; 6312225a122SSuresh Siddha int n; 6322225a122SSuresh Siddha 6332225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 6342225a122SSuresh Siddha regset = view->regsets + n; 6352225a122SSuresh Siddha if (regset->core_note_type == type) 6362225a122SSuresh Siddha return regset; 6372225a122SSuresh Siddha } 6382225a122SSuresh Siddha 6392225a122SSuresh Siddha return NULL; 6402225a122SSuresh Siddha } 6412225a122SSuresh Siddha 6422225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 6432225a122SSuresh Siddha struct iovec *kiov) 6442225a122SSuresh Siddha { 6452225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 6462225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 6472225a122SSuresh Siddha int regset_no; 6482225a122SSuresh Siddha 6492225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 650c6a0dd7eSSuresh Siddha return -EINVAL; 6512225a122SSuresh Siddha 6522225a122SSuresh Siddha regset_no = regset - view->regsets; 6532225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 6542225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 6552225a122SSuresh Siddha 6562225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 6572225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 6582225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6592225a122SSuresh Siddha else 6602225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 6612225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6622225a122SSuresh Siddha } 6632225a122SSuresh Siddha 6642225a122SSuresh Siddha #endif 6652225a122SSuresh Siddha 6661da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 6674abf9869SNamhyung Kim unsigned long addr, unsigned long data) 6681da177e4SLinus Torvalds { 669fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 6701da177e4SLinus Torvalds int ret = -EIO; 671544b2c91STejun Heo siginfo_t siginfo, *si; 6729fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 6739fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 674fca26f26STejun Heo unsigned long flags; 6751da177e4SLinus Torvalds 6761da177e4SLinus Torvalds switch (request) { 67716c3e389SRoland McGrath case PTRACE_PEEKTEXT: 67816c3e389SRoland McGrath case PTRACE_PEEKDATA: 67916c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 68016c3e389SRoland McGrath case PTRACE_POKETEXT: 68116c3e389SRoland McGrath case PTRACE_POKEDATA: 68216c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 68316c3e389SRoland McGrath 6841da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 6851da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 6861da177e4SLinus Torvalds #endif 6871da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 6881da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 6891da177e4SLinus Torvalds break; 6901da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 6919fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 6921da177e4SLinus Torvalds break; 693e16b2781SRoland McGrath 6941da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 695e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 696e16b2781SRoland McGrath if (!ret) 6979fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 6981da177e4SLinus Torvalds break; 699e16b2781SRoland McGrath 7001da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 7019fed81dcSNamhyung Kim if (copy_from_user(&siginfo, datavp, sizeof siginfo)) 702e16b2781SRoland McGrath ret = -EFAULT; 703e16b2781SRoland McGrath else 704e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 7051da177e4SLinus Torvalds break; 706e16b2781SRoland McGrath 707fca26f26STejun Heo case PTRACE_INTERRUPT: 708fca26f26STejun Heo /* 709fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 710fca26f26STejun Heo * control. At least one trap is guaranteed to happen 711fca26f26STejun Heo * after this request. If @child is already trapped, the 712fca26f26STejun Heo * current trap is not disturbed and another trap will 713fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 714fca26f26STejun Heo * 715fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 716fca26f26STejun Heo * the pending condition is cleared regardless. 717fca26f26STejun Heo */ 718fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 719fca26f26STejun Heo break; 720fca26f26STejun Heo 721544b2c91STejun Heo /* 722544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 723544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 724544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 725544b2c91STejun Heo * tracee into STOP. 726544b2c91STejun Heo */ 727fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 728544b2c91STejun Heo signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 729544b2c91STejun Heo 730544b2c91STejun Heo unlock_task_sighand(child, &flags); 731544b2c91STejun Heo ret = 0; 732544b2c91STejun Heo break; 733544b2c91STejun Heo 734544b2c91STejun Heo case PTRACE_LISTEN: 735544b2c91STejun Heo /* 736544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 737544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 738544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 739544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 740544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 741544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 742544b2c91STejun Heo */ 743544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 744544b2c91STejun Heo break; 745544b2c91STejun Heo 746544b2c91STejun Heo si = child->last_siginfo; 747544b2c91STejun Heo if (unlikely(!si || si->si_code >> 8 != PTRACE_EVENT_STOP)) 748544b2c91STejun Heo break; 749544b2c91STejun Heo 750544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 751544b2c91STejun Heo 752544b2c91STejun Heo /* 753544b2c91STejun Heo * If NOTIFY is set, it means event happened between start 754544b2c91STejun Heo * of this trap and now. Trigger re-trap immediately. 755544b2c91STejun Heo */ 756544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 757544b2c91STejun Heo signal_wake_up(child, true); 758fca26f26STejun Heo 759fca26f26STejun Heo unlock_task_sighand(child, &flags); 760fca26f26STejun Heo ret = 0; 761fca26f26STejun Heo break; 762fca26f26STejun Heo 7631bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 7641bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 7651bcf5482SAlexey Dobriyan break; 76636df29d7SRoland McGrath 7679c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 7689c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 769e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 7709c1a1259SMike Frysinger unsigned long tmp = 0; 7719c1a1259SMike Frysinger 772e0129ef9SOleg Nesterov ret = -ESRCH; 773e0129ef9SOleg Nesterov if (!mm) 774e0129ef9SOleg Nesterov break; 775e0129ef9SOleg Nesterov 7769c1a1259SMike Frysinger switch (addr) { 7779c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 778e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 7799c1a1259SMike Frysinger break; 7809c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 781e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 7829c1a1259SMike Frysinger break; 7839c1a1259SMike Frysinger default: 7849c1a1259SMike Frysinger break; 7859c1a1259SMike Frysinger } 786e0129ef9SOleg Nesterov mmput(mm); 7879c1a1259SMike Frysinger 7889fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 7899c1a1259SMike Frysinger break; 7909c1a1259SMike Frysinger } 7919c1a1259SMike Frysinger #endif 7929c1a1259SMike Frysinger 79336df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 79436df29d7SRoland McGrath case PTRACE_SINGLESTEP: 79536df29d7SRoland McGrath #endif 7965b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 7975b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 7985b88abbfSRoland McGrath #endif 79936df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 80036df29d7SRoland McGrath case PTRACE_SYSEMU: 80136df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 80236df29d7SRoland McGrath #endif 80336df29d7SRoland McGrath case PTRACE_SYSCALL: 80436df29d7SRoland McGrath case PTRACE_CONT: 80536df29d7SRoland McGrath return ptrace_resume(child, request, data); 80636df29d7SRoland McGrath 80736df29d7SRoland McGrath case PTRACE_KILL: 80836df29d7SRoland McGrath if (child->exit_state) /* already dead */ 80936df29d7SRoland McGrath return 0; 81036df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 81136df29d7SRoland McGrath 8122225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8132225a122SSuresh Siddha case PTRACE_GETREGSET: 8142225a122SSuresh Siddha case PTRACE_SETREGSET: 8152225a122SSuresh Siddha { 8162225a122SSuresh Siddha struct iovec kiov; 8179fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 8182225a122SSuresh Siddha 8192225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 8202225a122SSuresh Siddha return -EFAULT; 8212225a122SSuresh Siddha 8222225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 8232225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 8242225a122SSuresh Siddha return -EFAULT; 8252225a122SSuresh Siddha 8262225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 8272225a122SSuresh Siddha if (!ret) 8282225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 8292225a122SSuresh Siddha break; 8302225a122SSuresh Siddha } 8312225a122SSuresh Siddha #endif 8321da177e4SLinus Torvalds default: 8331da177e4SLinus Torvalds break; 8341da177e4SLinus Torvalds } 8351da177e4SLinus Torvalds 8361da177e4SLinus Torvalds return ret; 8371da177e4SLinus Torvalds } 838481bed45SChristoph Hellwig 8398053bdd5SOleg Nesterov static struct task_struct *ptrace_get_task_struct(pid_t pid) 8406b9c7ed8SChristoph Hellwig { 8416b9c7ed8SChristoph Hellwig struct task_struct *child; 8426b9c7ed8SChristoph Hellwig 8438053bdd5SOleg Nesterov rcu_read_lock(); 844228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 845481bed45SChristoph Hellwig if (child) 846481bed45SChristoph Hellwig get_task_struct(child); 8478053bdd5SOleg Nesterov rcu_read_unlock(); 848f400e198SSukadev Bhattiprolu 849481bed45SChristoph Hellwig if (!child) 8506b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 8516b9c7ed8SChristoph Hellwig return child; 852481bed45SChristoph Hellwig } 853481bed45SChristoph Hellwig 8540ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 8550ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 8560ac15559SChristoph Hellwig #endif 8570ac15559SChristoph Hellwig 8584abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 8594abf9869SNamhyung Kim unsigned long, data) 860481bed45SChristoph Hellwig { 861481bed45SChristoph Hellwig struct task_struct *child; 862481bed45SChristoph Hellwig long ret; 863481bed45SChristoph Hellwig 8646b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 8656b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 8666ea6dd93SHaavard Skinnemoen if (!ret) 8676ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 868481bed45SChristoph Hellwig goto out; 8696b9c7ed8SChristoph Hellwig } 8706b9c7ed8SChristoph Hellwig 8716b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 8726b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 8736b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 8746b9c7ed8SChristoph Hellwig goto out; 8756b9c7ed8SChristoph Hellwig } 876481bed45SChristoph Hellwig 8773544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 8783544d72aSTejun Heo ret = ptrace_attach(child, request, data); 8790ac15559SChristoph Hellwig /* 8800ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 8810ac15559SChristoph Hellwig * a ptrace attach. 8820ac15559SChristoph Hellwig */ 8830ac15559SChristoph Hellwig if (!ret) 8840ac15559SChristoph Hellwig arch_ptrace_attach(child); 885005f18dfSChristoph Hellwig goto out_put_task_struct; 886481bed45SChristoph Hellwig } 887481bed45SChristoph Hellwig 888fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 889fca26f26STejun Heo request == PTRACE_INTERRUPT); 890481bed45SChristoph Hellwig if (ret < 0) 891481bed45SChristoph Hellwig goto out_put_task_struct; 892481bed45SChristoph Hellwig 893481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 894481bed45SChristoph Hellwig 895481bed45SChristoph Hellwig out_put_task_struct: 896481bed45SChristoph Hellwig put_task_struct(child); 897481bed45SChristoph Hellwig out: 898481bed45SChristoph Hellwig return ret; 899481bed45SChristoph Hellwig } 90076647323SAlexey Dobriyan 9014abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 9024abf9869SNamhyung Kim unsigned long data) 90376647323SAlexey Dobriyan { 90476647323SAlexey Dobriyan unsigned long tmp; 90576647323SAlexey Dobriyan int copied; 90676647323SAlexey Dobriyan 90776647323SAlexey Dobriyan copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); 90876647323SAlexey Dobriyan if (copied != sizeof(tmp)) 90976647323SAlexey Dobriyan return -EIO; 91076647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 91176647323SAlexey Dobriyan } 912f284ce72SAlexey Dobriyan 9134abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 9144abf9869SNamhyung Kim unsigned long data) 915f284ce72SAlexey Dobriyan { 916f284ce72SAlexey Dobriyan int copied; 917f284ce72SAlexey Dobriyan 918f284ce72SAlexey Dobriyan copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); 919f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 920f284ce72SAlexey Dobriyan } 921032d82d9SRoland McGrath 92296b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 923032d82d9SRoland McGrath #include <linux/compat.h> 924032d82d9SRoland McGrath 925032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 926032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 927032d82d9SRoland McGrath { 928032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 929032d82d9SRoland McGrath compat_ulong_t word; 930e16b2781SRoland McGrath siginfo_t siginfo; 931032d82d9SRoland McGrath int ret; 932032d82d9SRoland McGrath 933032d82d9SRoland McGrath switch (request) { 934032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 935032d82d9SRoland McGrath case PTRACE_PEEKDATA: 936032d82d9SRoland McGrath ret = access_process_vm(child, addr, &word, sizeof(word), 0); 937032d82d9SRoland McGrath if (ret != sizeof(word)) 938032d82d9SRoland McGrath ret = -EIO; 939032d82d9SRoland McGrath else 940032d82d9SRoland McGrath ret = put_user(word, datap); 941032d82d9SRoland McGrath break; 942032d82d9SRoland McGrath 943032d82d9SRoland McGrath case PTRACE_POKETEXT: 944032d82d9SRoland McGrath case PTRACE_POKEDATA: 945032d82d9SRoland McGrath ret = access_process_vm(child, addr, &data, sizeof(data), 1); 946032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 947032d82d9SRoland McGrath break; 948032d82d9SRoland McGrath 949032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 950032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 951032d82d9SRoland McGrath break; 952032d82d9SRoland McGrath 953e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 954e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 955e16b2781SRoland McGrath if (!ret) 956e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 957e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 958e16b2781SRoland McGrath &siginfo); 959e16b2781SRoland McGrath break; 960e16b2781SRoland McGrath 961e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 962e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 963e16b2781SRoland McGrath if (copy_siginfo_from_user32( 964e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 965e16b2781SRoland McGrath ret = -EFAULT; 966e16b2781SRoland McGrath else 967e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 968e16b2781SRoland McGrath break; 9692225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 9702225a122SSuresh Siddha case PTRACE_GETREGSET: 9712225a122SSuresh Siddha case PTRACE_SETREGSET: 9722225a122SSuresh Siddha { 9732225a122SSuresh Siddha struct iovec kiov; 9742225a122SSuresh Siddha struct compat_iovec __user *uiov = 9752225a122SSuresh Siddha (struct compat_iovec __user *) datap; 9762225a122SSuresh Siddha compat_uptr_t ptr; 9772225a122SSuresh Siddha compat_size_t len; 9782225a122SSuresh Siddha 9792225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 9802225a122SSuresh Siddha return -EFAULT; 9812225a122SSuresh Siddha 9822225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 9832225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 9842225a122SSuresh Siddha return -EFAULT; 9852225a122SSuresh Siddha 9862225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 9872225a122SSuresh Siddha kiov.iov_len = len; 9882225a122SSuresh Siddha 9892225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 9902225a122SSuresh Siddha if (!ret) 9912225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 9922225a122SSuresh Siddha break; 9932225a122SSuresh Siddha } 9942225a122SSuresh Siddha #endif 995e16b2781SRoland McGrath 996032d82d9SRoland McGrath default: 997032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 998032d82d9SRoland McGrath } 999032d82d9SRoland McGrath 1000032d82d9SRoland McGrath return ret; 1001032d82d9SRoland McGrath } 1002c269f196SRoland McGrath 1003c269f196SRoland McGrath asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, 1004c269f196SRoland McGrath compat_long_t addr, compat_long_t data) 1005c269f196SRoland McGrath { 1006c269f196SRoland McGrath struct task_struct *child; 1007c269f196SRoland McGrath long ret; 1008c269f196SRoland McGrath 1009c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1010c269f196SRoland McGrath ret = ptrace_traceme(); 1011c269f196SRoland McGrath goto out; 1012c269f196SRoland McGrath } 1013c269f196SRoland McGrath 1014c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 1015c269f196SRoland McGrath if (IS_ERR(child)) { 1016c269f196SRoland McGrath ret = PTR_ERR(child); 1017c269f196SRoland McGrath goto out; 1018c269f196SRoland McGrath } 1019c269f196SRoland McGrath 10203544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 10213544d72aSTejun Heo ret = ptrace_attach(child, request, data); 1022c269f196SRoland McGrath /* 1023c269f196SRoland McGrath * Some architectures need to do book-keeping after 1024c269f196SRoland McGrath * a ptrace attach. 1025c269f196SRoland McGrath */ 1026c269f196SRoland McGrath if (!ret) 1027c269f196SRoland McGrath arch_ptrace_attach(child); 1028c269f196SRoland McGrath goto out_put_task_struct; 1029c269f196SRoland McGrath } 1030c269f196SRoland McGrath 1031fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1032fca26f26STejun Heo request == PTRACE_INTERRUPT); 1033c269f196SRoland McGrath if (!ret) 1034c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 1035c269f196SRoland McGrath 1036c269f196SRoland McGrath out_put_task_struct: 1037c269f196SRoland McGrath put_task_struct(child); 1038c269f196SRoland McGrath out: 1039c269f196SRoland McGrath return ret; 1040c269f196SRoland McGrath } 104196b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1042bf26c018SFrederic Weisbecker 1043bf26c018SFrederic Weisbecker #ifdef CONFIG_HAVE_HW_BREAKPOINT 1044bf26c018SFrederic Weisbecker int ptrace_get_breakpoints(struct task_struct *tsk) 1045bf26c018SFrederic Weisbecker { 1046bf26c018SFrederic Weisbecker if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) 1047bf26c018SFrederic Weisbecker return 0; 1048bf26c018SFrederic Weisbecker 1049bf26c018SFrederic Weisbecker return -1; 1050bf26c018SFrederic Weisbecker } 1051bf26c018SFrederic Weisbecker 1052bf26c018SFrederic Weisbecker void ptrace_put_breakpoints(struct task_struct *tsk) 1053bf26c018SFrederic Weisbecker { 1054bf26c018SFrederic Weisbecker if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) 1055bf26c018SFrederic Weisbecker flush_ptrace_hw_breakpoint(tsk); 1056bf26c018SFrederic Weisbecker } 1057bf26c018SFrederic Weisbecker #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 1058