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> 261da177e4SLinus Torvalds 27bf53de90SMarkus Metzger 2862c124ffSTejun Heo static int ptrace_trapping_sleep_fn(void *flags) 2962c124ffSTejun Heo { 3062c124ffSTejun Heo schedule(); 3162c124ffSTejun Heo return 0; 3262c124ffSTejun Heo } 3362c124ffSTejun Heo 34bf53de90SMarkus Metzger /* 351da177e4SLinus Torvalds * ptrace a task: make the debugger its new parent and 361da177e4SLinus Torvalds * move it to the ptrace list. 371da177e4SLinus Torvalds * 381da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 391da177e4SLinus Torvalds */ 4036c8b586SIngo Molnar void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) 411da177e4SLinus Torvalds { 42f470021aSRoland McGrath BUG_ON(!list_empty(&child->ptrace_entry)); 43f470021aSRoland McGrath list_add(&child->ptrace_entry, &new_parent->ptraced); 441da177e4SLinus Torvalds child->parent = new_parent; 451da177e4SLinus Torvalds } 461da177e4SLinus Torvalds 47e3bd058fSTejun Heo /** 48e3bd058fSTejun Heo * __ptrace_unlink - unlink ptracee and restore its execution state 49e3bd058fSTejun Heo * @child: ptracee to be unlinked 501da177e4SLinus Torvalds * 510e9f0a4aSTejun Heo * Remove @child from the ptrace list, move it back to the original parent, 520e9f0a4aSTejun Heo * and restore the execution state so that it conforms to the group stop 530e9f0a4aSTejun Heo * state. 540e9f0a4aSTejun Heo * 550e9f0a4aSTejun Heo * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer 560e9f0a4aSTejun Heo * exiting. For PTRACE_DETACH, unless the ptracee has been killed between 570e9f0a4aSTejun Heo * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. 580e9f0a4aSTejun Heo * If the ptracer is exiting, the ptracee can be in any state. 590e9f0a4aSTejun Heo * 600e9f0a4aSTejun Heo * After detach, the ptracee should be in a state which conforms to the 610e9f0a4aSTejun Heo * group stop. If the group is stopped or in the process of stopping, the 620e9f0a4aSTejun Heo * ptracee should be put into TASK_STOPPED; otherwise, it should be woken 630e9f0a4aSTejun Heo * up from TASK_TRACED. 640e9f0a4aSTejun Heo * 650e9f0a4aSTejun Heo * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, 660e9f0a4aSTejun Heo * it goes through TRACED -> RUNNING -> STOPPED transition which is similar 670e9f0a4aSTejun Heo * to but in the opposite direction of what happens while attaching to a 680e9f0a4aSTejun Heo * stopped task. However, in this direction, the intermediate RUNNING 690e9f0a4aSTejun Heo * state is not hidden even from the current ptracer and if it immediately 700e9f0a4aSTejun Heo * re-attaches and performs a WNOHANG wait(2), it may fail. 71e3bd058fSTejun Heo * 72e3bd058fSTejun Heo * CONTEXT: 73e3bd058fSTejun Heo * write_lock_irq(tasklist_lock) 741da177e4SLinus Torvalds */ 7536c8b586SIngo Molnar void __ptrace_unlink(struct task_struct *child) 761da177e4SLinus Torvalds { 775ecfbae0SOleg Nesterov BUG_ON(!child->ptrace); 785ecfbae0SOleg Nesterov 791da177e4SLinus Torvalds child->ptrace = 0; 801da177e4SLinus Torvalds child->parent = child->real_parent; 81f470021aSRoland McGrath list_del_init(&child->ptrace_entry); 821da177e4SLinus Torvalds 831da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 840e9f0a4aSTejun Heo 851da177e4SLinus Torvalds /* 8673ddff2bSTejun Heo * Clear all pending traps and TRAPPING. TRAPPING should be 8773ddff2bSTejun Heo * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. 8873ddff2bSTejun Heo */ 8973ddff2bSTejun Heo task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); 9073ddff2bSTejun Heo task_clear_jobctl_trapping(child); 9173ddff2bSTejun Heo 9273ddff2bSTejun Heo /* 93a8f072c1STejun Heo * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and 940e9f0a4aSTejun Heo * @child isn't dead. 951da177e4SLinus Torvalds */ 960e9f0a4aSTejun Heo if (!(child->flags & PF_EXITING) && 970e9f0a4aSTejun Heo (child->signal->flags & SIGNAL_STOP_STOPPED || 980e9f0a4aSTejun Heo child->signal->group_stop_count)) 99a8f072c1STejun Heo child->jobctl |= JOBCTL_STOP_PENDING; 1000e9f0a4aSTejun Heo 1010e9f0a4aSTejun Heo /* 1020e9f0a4aSTejun Heo * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick 1030e9f0a4aSTejun Heo * @child in the butt. Note that @resume should be used iff @child 1040e9f0a4aSTejun Heo * is in TASK_TRACED; otherwise, we might unduly disrupt 1050e9f0a4aSTejun Heo * TASK_KILLABLE sleeps. 1060e9f0a4aSTejun Heo */ 107a8f072c1STejun Heo if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) 1080e9f0a4aSTejun Heo signal_wake_up(child, task_is_traced(child)); 1090e9f0a4aSTejun Heo 1101da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 1111da177e4SLinus Torvalds } 1121da177e4SLinus Torvalds 113755e276bSTejun Heo /** 114755e276bSTejun Heo * ptrace_check_attach - check whether ptracee is ready for ptrace operation 115755e276bSTejun Heo * @child: ptracee to check for 116755e276bSTejun Heo * @ignore_state: don't check whether @child is currently %TASK_TRACED 117755e276bSTejun Heo * 118755e276bSTejun Heo * Check whether @child is being ptraced by %current and ready for further 119755e276bSTejun Heo * ptrace operations. If @ignore_state is %false, @child also should be in 120755e276bSTejun Heo * %TASK_TRACED state and on return the child is guaranteed to be traced 121755e276bSTejun Heo * and not executing. If @ignore_state is %true, @child can be in any 122755e276bSTejun Heo * state. 123755e276bSTejun Heo * 124755e276bSTejun Heo * CONTEXT: 125755e276bSTejun Heo * Grabs and releases tasklist_lock and @child->sighand->siglock. 126755e276bSTejun Heo * 127755e276bSTejun Heo * RETURNS: 128755e276bSTejun Heo * 0 on success, -ESRCH if %child is not ready. 1291da177e4SLinus Torvalds */ 130755e276bSTejun Heo int ptrace_check_attach(struct task_struct *child, bool ignore_state) 1311da177e4SLinus Torvalds { 1321da177e4SLinus Torvalds int ret = -ESRCH; 1331da177e4SLinus Torvalds 1341da177e4SLinus Torvalds /* 1351da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 1361da177e4SLinus Torvalds * possible race where someone else was tracing our child and 1371da177e4SLinus Torvalds * detached between these two checks. After this locked check, 1381da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 1391da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 1401da177e4SLinus Torvalds */ 1411da177e4SLinus Torvalds read_lock(&tasklist_lock); 142c0c0b649SOleg Nesterov if ((child->ptrace & PT_PTRACED) && child->parent == current) { 143c0c0b649SOleg Nesterov /* 144c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 145c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 146c0c0b649SOleg Nesterov */ 1471da177e4SLinus Torvalds spin_lock_irq(&child->sighand->siglock); 148321fb561SOleg Nesterov WARN_ON_ONCE(task_is_stopped(child)); 149544b2c91STejun Heo if (ignore_state || (task_is_traced(child) && 150544b2c91STejun Heo !(child->jobctl & JOBCTL_LISTENING))) 151321fb561SOleg Nesterov ret = 0; 1521da177e4SLinus Torvalds spin_unlock_irq(&child->sighand->siglock); 1531da177e4SLinus Torvalds } 1541da177e4SLinus Torvalds read_unlock(&tasklist_lock); 1551da177e4SLinus Torvalds 156755e276bSTejun Heo if (!ret && !ignore_state) 15785ba2d86SRoland McGrath ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; 1581da177e4SLinus Torvalds 1591da177e4SLinus Torvalds /* All systems go.. */ 1601da177e4SLinus Torvalds return ret; 1611da177e4SLinus Torvalds } 1621da177e4SLinus Torvalds 163006ebb40SStephen Smalley int __ptrace_may_access(struct task_struct *task, unsigned int mode) 164ab8d11beSMiklos Szeredi { 165c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 166b6dff3ecSDavid Howells 167df26c40eSEric W. Biederman /* May we inspect the given task? 168df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 169df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 170df26c40eSEric W. Biederman * 171df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 172df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 173df26c40eSEric W. Biederman * or halting the specified task is impossible. 174df26c40eSEric W. Biederman */ 175df26c40eSEric W. Biederman int dumpable = 0; 176df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 177df26c40eSEric W. Biederman if (task == current) 178df26c40eSEric W. Biederman return 0; 179c69e8d9cSDavid Howells rcu_read_lock(); 180c69e8d9cSDavid Howells tcred = __task_cred(task); 1818409cca7SSerge E. Hallyn if (cred->user->user_ns == tcred->user->user_ns && 1828409cca7SSerge E. Hallyn (cred->uid == tcred->euid && 1838409cca7SSerge E. Hallyn cred->uid == tcred->suid && 1848409cca7SSerge E. Hallyn cred->uid == tcred->uid && 1858409cca7SSerge E. Hallyn cred->gid == tcred->egid && 1868409cca7SSerge E. Hallyn cred->gid == tcred->sgid && 1878409cca7SSerge E. Hallyn cred->gid == tcred->gid)) 1888409cca7SSerge E. Hallyn goto ok; 1898409cca7SSerge E. Hallyn if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE)) 1908409cca7SSerge E. Hallyn goto ok; 191c69e8d9cSDavid Howells rcu_read_unlock(); 192ab8d11beSMiklos Szeredi return -EPERM; 1938409cca7SSerge E. Hallyn ok: 194c69e8d9cSDavid Howells rcu_read_unlock(); 195ab8d11beSMiklos Szeredi smp_rmb(); 196df26c40eSEric W. Biederman if (task->mm) 1976c5d5238SKawai, Hidehiro dumpable = get_dumpable(task->mm); 1988409cca7SSerge E. Hallyn if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE)) 199ab8d11beSMiklos Szeredi return -EPERM; 200ab8d11beSMiklos Szeredi 2019e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 202ab8d11beSMiklos Szeredi } 203ab8d11beSMiklos Szeredi 204006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 205ab8d11beSMiklos Szeredi { 206ab8d11beSMiklos Szeredi int err; 207ab8d11beSMiklos Szeredi task_lock(task); 208006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 209ab8d11beSMiklos Szeredi task_unlock(task); 2103a709703SRoland McGrath return !err; 211ab8d11beSMiklos Szeredi } 212ab8d11beSMiklos Szeredi 2133544d72aSTejun Heo static int ptrace_attach(struct task_struct *task, long request, 2143544d72aSTejun Heo unsigned long flags) 2151da177e4SLinus Torvalds { 2163544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 2171da177e4SLinus Torvalds int retval; 218f5b40e36SLinus Torvalds 2193544d72aSTejun Heo /* 2203544d72aSTejun Heo * SEIZE will enable new ptrace behaviors which will be implemented 2213544d72aSTejun Heo * gradually. SEIZE_DEVEL is used to prevent applications 2223544d72aSTejun Heo * expecting full SEIZE behaviors trapping on kernel commits which 2233544d72aSTejun Heo * are still in the process of implementing them. 2243544d72aSTejun Heo * 2253544d72aSTejun Heo * Only test programs for new ptrace behaviors being implemented 2263544d72aSTejun Heo * should set SEIZE_DEVEL. If unset, SEIZE will fail with -EIO. 2273544d72aSTejun Heo * 2283544d72aSTejun Heo * Once SEIZE behaviors are completely implemented, this flag and 2293544d72aSTejun Heo * the following test will be removed. 2303544d72aSTejun Heo */ 2313544d72aSTejun Heo retval = -EIO; 2323544d72aSTejun Heo if (seize && !(flags & PTRACE_SEIZE_DEVEL)) 2333544d72aSTejun Heo goto out; 2343544d72aSTejun Heo 235a5cb013dSAl Viro audit_ptrace(task); 236a5cb013dSAl Viro 2371da177e4SLinus Torvalds retval = -EPERM; 238b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 239b79b7ba9SOleg Nesterov goto out; 240bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 241f5b40e36SLinus Torvalds goto out; 242f5b40e36SLinus Torvalds 243f2f0b00aSOleg Nesterov /* 244f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 2455e751e99SDavid Howells * interference; SUID, SGID and LSM creds get determined differently 2465e751e99SDavid Howells * under ptrace. 247d84f4f99SDavid Howells */ 248793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 2499b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 250d84f4f99SDavid Howells goto out; 2514b105cbbSOleg Nesterov 252f5b40e36SLinus Torvalds task_lock(task); 253006ebb40SStephen Smalley retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); 2544b105cbbSOleg Nesterov task_unlock(task); 2551da177e4SLinus Torvalds if (retval) 2564b105cbbSOleg Nesterov goto unlock_creds; 2571da177e4SLinus Torvalds 2584b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 259b79b7ba9SOleg Nesterov retval = -EPERM; 260b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 2614b105cbbSOleg Nesterov goto unlock_tasklist; 262f2f0b00aSOleg Nesterov if (task->ptrace) 2634b105cbbSOleg Nesterov goto unlock_tasklist; 264b79b7ba9SOleg Nesterov 265f2f0b00aSOleg Nesterov task->ptrace = PT_PTRACED; 2663544d72aSTejun Heo if (seize) 2673544d72aSTejun Heo task->ptrace |= PT_SEIZED; 2688409cca7SSerge E. Hallyn if (task_ns_capable(task, CAP_SYS_PTRACE)) 2691da177e4SLinus Torvalds task->ptrace |= PT_PTRACE_CAP; 2701da177e4SLinus Torvalds 2711da177e4SLinus Torvalds __ptrace_link(task, current); 2723544d72aSTejun Heo 2733544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 2743544d72aSTejun Heo if (!seize) 27533e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 276b79b7ba9SOleg Nesterov 277d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 278d79fdd6dSTejun Heo 279d79fdd6dSTejun Heo /* 28073ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 281d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 282d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 283d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 284d79fdd6dSTejun Heo * for the transition to complete before returning from this 285d79fdd6dSTejun Heo * function. 286d79fdd6dSTejun Heo * 287d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 288d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 289d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 290d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 291d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 292d79fdd6dSTejun Heo * 293d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 294d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 295d79fdd6dSTejun Heo */ 2967dd3db54STejun Heo if (task_is_stopped(task) && 29773ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 298d79fdd6dSTejun Heo signal_wake_up(task, 1); 299d79fdd6dSTejun Heo 300d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 301d79fdd6dSTejun Heo 302b79b7ba9SOleg Nesterov retval = 0; 3034b105cbbSOleg Nesterov unlock_tasklist: 3044b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3054b105cbbSOleg Nesterov unlock_creds: 3069b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 307f5b40e36SLinus Torvalds out: 3080b1007c3STejun Heo if (!retval) 30962c124ffSTejun Heo wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, 31062c124ffSTejun Heo ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE); 3111da177e4SLinus Torvalds return retval; 3121da177e4SLinus Torvalds } 3131da177e4SLinus Torvalds 314f2f0b00aSOleg Nesterov /** 315f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 316f2f0b00aSOleg Nesterov * 317f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 318f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 319f2f0b00aSOleg Nesterov */ 320e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 321f2f0b00aSOleg Nesterov { 322f2f0b00aSOleg Nesterov int ret = -EPERM; 323f2f0b00aSOleg Nesterov 3244b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 3254b105cbbSOleg Nesterov /* Are we already being traced? */ 326f2f0b00aSOleg Nesterov if (!current->ptrace) { 327f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 328f2f0b00aSOleg Nesterov /* 329f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 330f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 331f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 332f2f0b00aSOleg Nesterov */ 333f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 334f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 335f2f0b00aSOleg Nesterov __ptrace_link(current, current->real_parent); 336f2f0b00aSOleg Nesterov } 337f2f0b00aSOleg Nesterov } 3384b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 3394b105cbbSOleg Nesterov 340f2f0b00aSOleg Nesterov return ret; 341f2f0b00aSOleg Nesterov } 342f2f0b00aSOleg Nesterov 34339c626aeSOleg Nesterov /* 34439c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 34539c626aeSOleg Nesterov */ 34639c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 34739c626aeSOleg Nesterov { 34839c626aeSOleg Nesterov int ret; 34939c626aeSOleg Nesterov spin_lock(&sigh->siglock); 35039c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 35139c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 35239c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 35339c626aeSOleg Nesterov return ret; 35439c626aeSOleg Nesterov } 35539c626aeSOleg Nesterov 35639c626aeSOleg Nesterov /* 35739c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 35839c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 35939c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 36039c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 36139c626aeSOleg Nesterov * 36239c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 36339c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 36439c626aeSOleg Nesterov * If it should reap itself, return true. 36539c626aeSOleg Nesterov * 366a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 367a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 368a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 369a7f0765eSOleg Nesterov * do_wait(). 37039c626aeSOleg Nesterov */ 37139c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 37239c626aeSOleg Nesterov { 3739843a1e9SOleg Nesterov bool dead; 3749843a1e9SOleg Nesterov 37539c626aeSOleg Nesterov __ptrace_unlink(p); 37639c626aeSOleg Nesterov 3779843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 3789843a1e9SOleg Nesterov return false; 3799843a1e9SOleg Nesterov 3809843a1e9SOleg Nesterov dead = !thread_group_leader(p); 3819843a1e9SOleg Nesterov 3829843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 38339c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 3849843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 385a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 386a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 38739c626aeSOleg Nesterov p->exit_signal = -1; 3889843a1e9SOleg Nesterov dead = true; 38939c626aeSOleg Nesterov } 390a7f0765eSOleg Nesterov } 39139c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 3929843a1e9SOleg Nesterov if (dead) 39339c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 3949843a1e9SOleg Nesterov return dead; 39539c626aeSOleg Nesterov } 39639c626aeSOleg Nesterov 397e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 3981da177e4SLinus Torvalds { 39939c626aeSOleg Nesterov bool dead = false; 4004576145cSOleg Nesterov 4017ed20e1aSJesper Juhl if (!valid_signal(data)) 4021da177e4SLinus Torvalds return -EIO; 4031da177e4SLinus Torvalds 4041da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 4051da177e4SLinus Torvalds ptrace_disable(child); 4067d941432SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 4071da177e4SLinus Torvalds 40895c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 40939c626aeSOleg Nesterov /* 41039c626aeSOleg Nesterov * This child can be already killed. Make sure de_thread() or 41139c626aeSOleg Nesterov * our sub-thread doing do_wait() didn't do release_task() yet. 41239c626aeSOleg Nesterov */ 41395c3eb76SOleg Nesterov if (child->ptrace) { 41495c3eb76SOleg Nesterov child->exit_code = data; 4154576145cSOleg Nesterov dead = __ptrace_detach(current, child); 41695c3eb76SOleg Nesterov } 4171da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 4181da177e4SLinus Torvalds 4194576145cSOleg Nesterov if (unlikely(dead)) 4204576145cSOleg Nesterov release_task(child); 4214576145cSOleg Nesterov 4221da177e4SLinus Torvalds return 0; 4231da177e4SLinus Torvalds } 4241da177e4SLinus Torvalds 42539c626aeSOleg Nesterov /* 426c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 427c7e49c14SOleg Nesterov * for writing, and returns with it held too. But note it can release 428c7e49c14SOleg Nesterov * and reacquire the lock. 42939c626aeSOleg Nesterov */ 43039c626aeSOleg Nesterov void exit_ptrace(struct task_struct *tracer) 431c4b5ed25SNamhyung Kim __releases(&tasklist_lock) 432c4b5ed25SNamhyung Kim __acquires(&tasklist_lock) 43339c626aeSOleg Nesterov { 43439c626aeSOleg Nesterov struct task_struct *p, *n; 43539c626aeSOleg Nesterov LIST_HEAD(ptrace_dead); 43639c626aeSOleg Nesterov 437c7e49c14SOleg Nesterov if (likely(list_empty(&tracer->ptraced))) 438c7e49c14SOleg Nesterov return; 439c7e49c14SOleg Nesterov 44039c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 44139c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 44239c626aeSOleg Nesterov list_add(&p->ptrace_entry, &ptrace_dead); 44339c626aeSOleg Nesterov } 44439c626aeSOleg Nesterov 445c7e49c14SOleg Nesterov write_unlock_irq(&tasklist_lock); 44639c626aeSOleg Nesterov BUG_ON(!list_empty(&tracer->ptraced)); 44739c626aeSOleg Nesterov 44839c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { 44939c626aeSOleg Nesterov list_del_init(&p->ptrace_entry); 45039c626aeSOleg Nesterov release_task(p); 45139c626aeSOleg Nesterov } 452c7e49c14SOleg Nesterov 453c7e49c14SOleg Nesterov write_lock_irq(&tasklist_lock); 45439c626aeSOleg Nesterov } 45539c626aeSOleg Nesterov 4561da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 4571da177e4SLinus Torvalds { 4581da177e4SLinus Torvalds int copied = 0; 4591da177e4SLinus Torvalds 4601da177e4SLinus Torvalds while (len > 0) { 4611da177e4SLinus Torvalds char buf[128]; 4621da177e4SLinus Torvalds int this_len, retval; 4631da177e4SLinus Torvalds 4641da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4651da177e4SLinus Torvalds retval = access_process_vm(tsk, src, buf, this_len, 0); 4661da177e4SLinus Torvalds if (!retval) { 4671da177e4SLinus Torvalds if (copied) 4681da177e4SLinus Torvalds break; 4691da177e4SLinus Torvalds return -EIO; 4701da177e4SLinus Torvalds } 4711da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 4721da177e4SLinus Torvalds return -EFAULT; 4731da177e4SLinus Torvalds copied += retval; 4741da177e4SLinus Torvalds src += retval; 4751da177e4SLinus Torvalds dst += retval; 4761da177e4SLinus Torvalds len -= retval; 4771da177e4SLinus Torvalds } 4781da177e4SLinus Torvalds return copied; 4791da177e4SLinus Torvalds } 4801da177e4SLinus Torvalds 4811da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 4821da177e4SLinus Torvalds { 4831da177e4SLinus Torvalds int copied = 0; 4841da177e4SLinus Torvalds 4851da177e4SLinus Torvalds while (len > 0) { 4861da177e4SLinus Torvalds char buf[128]; 4871da177e4SLinus Torvalds int this_len, retval; 4881da177e4SLinus Torvalds 4891da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 4901da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 4911da177e4SLinus Torvalds return -EFAULT; 4921da177e4SLinus Torvalds retval = access_process_vm(tsk, dst, buf, this_len, 1); 4931da177e4SLinus Torvalds if (!retval) { 4941da177e4SLinus Torvalds if (copied) 4951da177e4SLinus Torvalds break; 4961da177e4SLinus Torvalds return -EIO; 4971da177e4SLinus Torvalds } 4981da177e4SLinus Torvalds copied += retval; 4991da177e4SLinus Torvalds src += retval; 5001da177e4SLinus Torvalds dst += retval; 5011da177e4SLinus Torvalds len -= retval; 5021da177e4SLinus Torvalds } 5031da177e4SLinus Torvalds return copied; 5041da177e4SLinus Torvalds } 5051da177e4SLinus Torvalds 5064abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 5071da177e4SLinus Torvalds { 5081da177e4SLinus Torvalds child->ptrace &= ~PT_TRACE_MASK; 5091da177e4SLinus Torvalds 5101da177e4SLinus Torvalds if (data & PTRACE_O_TRACESYSGOOD) 5111da177e4SLinus Torvalds child->ptrace |= PT_TRACESYSGOOD; 5121da177e4SLinus Torvalds 5131da177e4SLinus Torvalds if (data & PTRACE_O_TRACEFORK) 5141da177e4SLinus Torvalds child->ptrace |= PT_TRACE_FORK; 5151da177e4SLinus Torvalds 5161da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORK) 5171da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK; 5181da177e4SLinus Torvalds 5191da177e4SLinus Torvalds if (data & PTRACE_O_TRACECLONE) 5201da177e4SLinus Torvalds child->ptrace |= PT_TRACE_CLONE; 5211da177e4SLinus Torvalds 5221da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXEC) 5231da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXEC; 5241da177e4SLinus Torvalds 5251da177e4SLinus Torvalds if (data & PTRACE_O_TRACEVFORKDONE) 5261da177e4SLinus Torvalds child->ptrace |= PT_TRACE_VFORK_DONE; 5271da177e4SLinus Torvalds 5281da177e4SLinus Torvalds if (data & PTRACE_O_TRACEEXIT) 5291da177e4SLinus Torvalds child->ptrace |= PT_TRACE_EXIT; 5301da177e4SLinus Torvalds 5311da177e4SLinus Torvalds return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; 5321da177e4SLinus Torvalds } 5331da177e4SLinus Torvalds 534e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 5351da177e4SLinus Torvalds { 536e4961254SOleg Nesterov unsigned long flags; 5371da177e4SLinus Torvalds int error = -ESRCH; 5381da177e4SLinus Torvalds 539e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5401da177e4SLinus Torvalds error = -EINVAL; 5411da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 542e16b2781SRoland McGrath *info = *child->last_siginfo; 5431da177e4SLinus Torvalds error = 0; 5441da177e4SLinus Torvalds } 545e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5461da177e4SLinus Torvalds } 5471da177e4SLinus Torvalds return error; 5481da177e4SLinus Torvalds } 5491da177e4SLinus Torvalds 550e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 5511da177e4SLinus Torvalds { 552e4961254SOleg Nesterov unsigned long flags; 5531da177e4SLinus Torvalds int error = -ESRCH; 5541da177e4SLinus Torvalds 555e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 5561da177e4SLinus Torvalds error = -EINVAL; 5571da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 558e16b2781SRoland McGrath *child->last_siginfo = *info; 5591da177e4SLinus Torvalds error = 0; 5601da177e4SLinus Torvalds } 561e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 5621da177e4SLinus Torvalds } 5631da177e4SLinus Torvalds return error; 5641da177e4SLinus Torvalds } 5651da177e4SLinus Torvalds 56636df29d7SRoland McGrath 56736df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 56836df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 56936df29d7SRoland McGrath #else 57036df29d7SRoland McGrath #define is_singlestep(request) 0 57136df29d7SRoland McGrath #endif 57236df29d7SRoland McGrath 5735b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 5745b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 5755b88abbfSRoland McGrath #else 5765b88abbfSRoland McGrath #define is_singleblock(request) 0 5775b88abbfSRoland McGrath #endif 5785b88abbfSRoland McGrath 57936df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 58036df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 58136df29d7SRoland McGrath #else 58236df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 58336df29d7SRoland McGrath #endif 58436df29d7SRoland McGrath 5854abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 5864abf9869SNamhyung Kim unsigned long data) 58736df29d7SRoland McGrath { 58836df29d7SRoland McGrath if (!valid_signal(data)) 58936df29d7SRoland McGrath return -EIO; 59036df29d7SRoland McGrath 59136df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 59236df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 59336df29d7SRoland McGrath else 59436df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 59536df29d7SRoland McGrath 59636df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 59736df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 59836df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 59936df29d7SRoland McGrath else 60036df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 60136df29d7SRoland McGrath #endif 60236df29d7SRoland McGrath 6035b88abbfSRoland McGrath if (is_singleblock(request)) { 6045b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 6055b88abbfSRoland McGrath return -EIO; 6065b88abbfSRoland McGrath user_enable_block_step(child); 6075b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 60836df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 60936df29d7SRoland McGrath return -EIO; 61036df29d7SRoland McGrath user_enable_single_step(child); 6113a709703SRoland McGrath } else { 61236df29d7SRoland McGrath user_disable_single_step(child); 6133a709703SRoland McGrath } 61436df29d7SRoland McGrath 61536df29d7SRoland McGrath child->exit_code = data; 6160666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 61736df29d7SRoland McGrath 61836df29d7SRoland McGrath return 0; 61936df29d7SRoland McGrath } 62036df29d7SRoland McGrath 6212225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 6222225a122SSuresh Siddha 6232225a122SSuresh Siddha static const struct user_regset * 6242225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 6252225a122SSuresh Siddha { 6262225a122SSuresh Siddha const struct user_regset *regset; 6272225a122SSuresh Siddha int n; 6282225a122SSuresh Siddha 6292225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 6302225a122SSuresh Siddha regset = view->regsets + n; 6312225a122SSuresh Siddha if (regset->core_note_type == type) 6322225a122SSuresh Siddha return regset; 6332225a122SSuresh Siddha } 6342225a122SSuresh Siddha 6352225a122SSuresh Siddha return NULL; 6362225a122SSuresh Siddha } 6372225a122SSuresh Siddha 6382225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 6392225a122SSuresh Siddha struct iovec *kiov) 6402225a122SSuresh Siddha { 6412225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 6422225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 6432225a122SSuresh Siddha int regset_no; 6442225a122SSuresh Siddha 6452225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 646c6a0dd7eSSuresh Siddha return -EINVAL; 6472225a122SSuresh Siddha 6482225a122SSuresh Siddha regset_no = regset - view->regsets; 6492225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 6502225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 6512225a122SSuresh Siddha 6522225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 6532225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 6542225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6552225a122SSuresh Siddha else 6562225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 6572225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 6582225a122SSuresh Siddha } 6592225a122SSuresh Siddha 6602225a122SSuresh Siddha #endif 6612225a122SSuresh Siddha 6621da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 6634abf9869SNamhyung Kim unsigned long addr, unsigned long data) 6641da177e4SLinus Torvalds { 665fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 6661da177e4SLinus Torvalds int ret = -EIO; 667544b2c91STejun Heo siginfo_t siginfo, *si; 6689fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 6699fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 670fca26f26STejun Heo unsigned long flags; 6711da177e4SLinus Torvalds 6721da177e4SLinus Torvalds switch (request) { 67316c3e389SRoland McGrath case PTRACE_PEEKTEXT: 67416c3e389SRoland McGrath case PTRACE_PEEKDATA: 67516c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 67616c3e389SRoland McGrath case PTRACE_POKETEXT: 67716c3e389SRoland McGrath case PTRACE_POKEDATA: 67816c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 67916c3e389SRoland McGrath 6801da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 6811da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 6821da177e4SLinus Torvalds #endif 6831da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 6841da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 6851da177e4SLinus Torvalds break; 6861da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 6879fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 6881da177e4SLinus Torvalds break; 689e16b2781SRoland McGrath 6901da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 691e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 692e16b2781SRoland McGrath if (!ret) 6939fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 6941da177e4SLinus Torvalds break; 695e16b2781SRoland McGrath 6961da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 6979fed81dcSNamhyung Kim if (copy_from_user(&siginfo, datavp, sizeof siginfo)) 698e16b2781SRoland McGrath ret = -EFAULT; 699e16b2781SRoland McGrath else 700e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 7011da177e4SLinus Torvalds break; 702e16b2781SRoland McGrath 703fca26f26STejun Heo case PTRACE_INTERRUPT: 704fca26f26STejun Heo /* 705fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 706fca26f26STejun Heo * control. At least one trap is guaranteed to happen 707fca26f26STejun Heo * after this request. If @child is already trapped, the 708fca26f26STejun Heo * current trap is not disturbed and another trap will 709fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 710fca26f26STejun Heo * 711fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 712fca26f26STejun Heo * the pending condition is cleared regardless. 713fca26f26STejun Heo */ 714fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 715fca26f26STejun Heo break; 716fca26f26STejun Heo 717544b2c91STejun Heo /* 718544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 719544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 720544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 721544b2c91STejun Heo * tracee into STOP. 722544b2c91STejun Heo */ 723fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 724544b2c91STejun Heo signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 725544b2c91STejun Heo 726544b2c91STejun Heo unlock_task_sighand(child, &flags); 727544b2c91STejun Heo ret = 0; 728544b2c91STejun Heo break; 729544b2c91STejun Heo 730544b2c91STejun Heo case PTRACE_LISTEN: 731544b2c91STejun Heo /* 732544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 733544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 734544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 735544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 736544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 737544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 738544b2c91STejun Heo */ 739544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 740544b2c91STejun Heo break; 741544b2c91STejun Heo 742544b2c91STejun Heo si = child->last_siginfo; 743544b2c91STejun Heo if (unlikely(!si || si->si_code >> 8 != PTRACE_EVENT_STOP)) 744544b2c91STejun Heo break; 745544b2c91STejun Heo 746544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 747544b2c91STejun Heo 748544b2c91STejun Heo /* 749544b2c91STejun Heo * If NOTIFY is set, it means event happened between start 750544b2c91STejun Heo * of this trap and now. Trigger re-trap immediately. 751544b2c91STejun Heo */ 752544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 753544b2c91STejun Heo signal_wake_up(child, true); 754fca26f26STejun Heo 755fca26f26STejun Heo unlock_task_sighand(child, &flags); 756fca26f26STejun Heo ret = 0; 757fca26f26STejun Heo break; 758fca26f26STejun Heo 7591bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 7601bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 7611bcf5482SAlexey Dobriyan break; 76236df29d7SRoland McGrath 7639c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 7649c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 765e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 7669c1a1259SMike Frysinger unsigned long tmp = 0; 7679c1a1259SMike Frysinger 768e0129ef9SOleg Nesterov ret = -ESRCH; 769e0129ef9SOleg Nesterov if (!mm) 770e0129ef9SOleg Nesterov break; 771e0129ef9SOleg Nesterov 7729c1a1259SMike Frysinger switch (addr) { 7739c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 774e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 7759c1a1259SMike Frysinger break; 7769c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 777e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 7789c1a1259SMike Frysinger break; 7799c1a1259SMike Frysinger default: 7809c1a1259SMike Frysinger break; 7819c1a1259SMike Frysinger } 782e0129ef9SOleg Nesterov mmput(mm); 7839c1a1259SMike Frysinger 7849fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 7859c1a1259SMike Frysinger break; 7869c1a1259SMike Frysinger } 7879c1a1259SMike Frysinger #endif 7889c1a1259SMike Frysinger 78936df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 79036df29d7SRoland McGrath case PTRACE_SINGLESTEP: 79136df29d7SRoland McGrath #endif 7925b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 7935b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 7945b88abbfSRoland McGrath #endif 79536df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 79636df29d7SRoland McGrath case PTRACE_SYSEMU: 79736df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 79836df29d7SRoland McGrath #endif 79936df29d7SRoland McGrath case PTRACE_SYSCALL: 80036df29d7SRoland McGrath case PTRACE_CONT: 80136df29d7SRoland McGrath return ptrace_resume(child, request, data); 80236df29d7SRoland McGrath 80336df29d7SRoland McGrath case PTRACE_KILL: 80436df29d7SRoland McGrath if (child->exit_state) /* already dead */ 80536df29d7SRoland McGrath return 0; 80636df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 80736df29d7SRoland McGrath 8082225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8092225a122SSuresh Siddha case PTRACE_GETREGSET: 8102225a122SSuresh Siddha case PTRACE_SETREGSET: 8112225a122SSuresh Siddha { 8122225a122SSuresh Siddha struct iovec kiov; 8139fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 8142225a122SSuresh Siddha 8152225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 8162225a122SSuresh Siddha return -EFAULT; 8172225a122SSuresh Siddha 8182225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 8192225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 8202225a122SSuresh Siddha return -EFAULT; 8212225a122SSuresh Siddha 8222225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 8232225a122SSuresh Siddha if (!ret) 8242225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 8252225a122SSuresh Siddha break; 8262225a122SSuresh Siddha } 8272225a122SSuresh Siddha #endif 8281da177e4SLinus Torvalds default: 8291da177e4SLinus Torvalds break; 8301da177e4SLinus Torvalds } 8311da177e4SLinus Torvalds 8321da177e4SLinus Torvalds return ret; 8331da177e4SLinus Torvalds } 834481bed45SChristoph Hellwig 8358053bdd5SOleg Nesterov static struct task_struct *ptrace_get_task_struct(pid_t pid) 8366b9c7ed8SChristoph Hellwig { 8376b9c7ed8SChristoph Hellwig struct task_struct *child; 8386b9c7ed8SChristoph Hellwig 8398053bdd5SOleg Nesterov rcu_read_lock(); 840228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 841481bed45SChristoph Hellwig if (child) 842481bed45SChristoph Hellwig get_task_struct(child); 8438053bdd5SOleg Nesterov rcu_read_unlock(); 844f400e198SSukadev Bhattiprolu 845481bed45SChristoph Hellwig if (!child) 8466b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 8476b9c7ed8SChristoph Hellwig return child; 848481bed45SChristoph Hellwig } 849481bed45SChristoph Hellwig 8500ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 8510ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 8520ac15559SChristoph Hellwig #endif 8530ac15559SChristoph Hellwig 8544abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 8554abf9869SNamhyung Kim unsigned long, data) 856481bed45SChristoph Hellwig { 857481bed45SChristoph Hellwig struct task_struct *child; 858481bed45SChristoph Hellwig long ret; 859481bed45SChristoph Hellwig 8606b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 8616b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 8626ea6dd93SHaavard Skinnemoen if (!ret) 8636ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 864481bed45SChristoph Hellwig goto out; 8656b9c7ed8SChristoph Hellwig } 8666b9c7ed8SChristoph Hellwig 8676b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 8686b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 8696b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 8706b9c7ed8SChristoph Hellwig goto out; 8716b9c7ed8SChristoph Hellwig } 872481bed45SChristoph Hellwig 8733544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 8743544d72aSTejun Heo ret = ptrace_attach(child, request, data); 8750ac15559SChristoph Hellwig /* 8760ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 8770ac15559SChristoph Hellwig * a ptrace attach. 8780ac15559SChristoph Hellwig */ 8790ac15559SChristoph Hellwig if (!ret) 8800ac15559SChristoph Hellwig arch_ptrace_attach(child); 881005f18dfSChristoph Hellwig goto out_put_task_struct; 882481bed45SChristoph Hellwig } 883481bed45SChristoph Hellwig 884fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 885fca26f26STejun Heo request == PTRACE_INTERRUPT); 886481bed45SChristoph Hellwig if (ret < 0) 887481bed45SChristoph Hellwig goto out_put_task_struct; 888481bed45SChristoph Hellwig 889481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 890481bed45SChristoph Hellwig 891481bed45SChristoph Hellwig out_put_task_struct: 892481bed45SChristoph Hellwig put_task_struct(child); 893481bed45SChristoph Hellwig out: 894481bed45SChristoph Hellwig return ret; 895481bed45SChristoph Hellwig } 89676647323SAlexey Dobriyan 8974abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 8984abf9869SNamhyung Kim unsigned long data) 89976647323SAlexey Dobriyan { 90076647323SAlexey Dobriyan unsigned long tmp; 90176647323SAlexey Dobriyan int copied; 90276647323SAlexey Dobriyan 90376647323SAlexey Dobriyan copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); 90476647323SAlexey Dobriyan if (copied != sizeof(tmp)) 90576647323SAlexey Dobriyan return -EIO; 90676647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 90776647323SAlexey Dobriyan } 908f284ce72SAlexey Dobriyan 9094abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 9104abf9869SNamhyung Kim unsigned long data) 911f284ce72SAlexey Dobriyan { 912f284ce72SAlexey Dobriyan int copied; 913f284ce72SAlexey Dobriyan 914f284ce72SAlexey Dobriyan copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); 915f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 916f284ce72SAlexey Dobriyan } 917032d82d9SRoland McGrath 91896b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 919032d82d9SRoland McGrath #include <linux/compat.h> 920032d82d9SRoland McGrath 921032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 922032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 923032d82d9SRoland McGrath { 924032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 925032d82d9SRoland McGrath compat_ulong_t word; 926e16b2781SRoland McGrath siginfo_t siginfo; 927032d82d9SRoland McGrath int ret; 928032d82d9SRoland McGrath 929032d82d9SRoland McGrath switch (request) { 930032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 931032d82d9SRoland McGrath case PTRACE_PEEKDATA: 932032d82d9SRoland McGrath ret = access_process_vm(child, addr, &word, sizeof(word), 0); 933032d82d9SRoland McGrath if (ret != sizeof(word)) 934032d82d9SRoland McGrath ret = -EIO; 935032d82d9SRoland McGrath else 936032d82d9SRoland McGrath ret = put_user(word, datap); 937032d82d9SRoland McGrath break; 938032d82d9SRoland McGrath 939032d82d9SRoland McGrath case PTRACE_POKETEXT: 940032d82d9SRoland McGrath case PTRACE_POKEDATA: 941032d82d9SRoland McGrath ret = access_process_vm(child, addr, &data, sizeof(data), 1); 942032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 943032d82d9SRoland McGrath break; 944032d82d9SRoland McGrath 945032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 946032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 947032d82d9SRoland McGrath break; 948032d82d9SRoland McGrath 949e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 950e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 951e16b2781SRoland McGrath if (!ret) 952e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 953e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 954e16b2781SRoland McGrath &siginfo); 955e16b2781SRoland McGrath break; 956e16b2781SRoland McGrath 957e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 958e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 959e16b2781SRoland McGrath if (copy_siginfo_from_user32( 960e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 961e16b2781SRoland McGrath ret = -EFAULT; 962e16b2781SRoland McGrath else 963e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 964e16b2781SRoland McGrath break; 9652225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 9662225a122SSuresh Siddha case PTRACE_GETREGSET: 9672225a122SSuresh Siddha case PTRACE_SETREGSET: 9682225a122SSuresh Siddha { 9692225a122SSuresh Siddha struct iovec kiov; 9702225a122SSuresh Siddha struct compat_iovec __user *uiov = 9712225a122SSuresh Siddha (struct compat_iovec __user *) datap; 9722225a122SSuresh Siddha compat_uptr_t ptr; 9732225a122SSuresh Siddha compat_size_t len; 9742225a122SSuresh Siddha 9752225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 9762225a122SSuresh Siddha return -EFAULT; 9772225a122SSuresh Siddha 9782225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 9792225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 9802225a122SSuresh Siddha return -EFAULT; 9812225a122SSuresh Siddha 9822225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 9832225a122SSuresh Siddha kiov.iov_len = len; 9842225a122SSuresh Siddha 9852225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 9862225a122SSuresh Siddha if (!ret) 9872225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 9882225a122SSuresh Siddha break; 9892225a122SSuresh Siddha } 9902225a122SSuresh Siddha #endif 991e16b2781SRoland McGrath 992032d82d9SRoland McGrath default: 993032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 994032d82d9SRoland McGrath } 995032d82d9SRoland McGrath 996032d82d9SRoland McGrath return ret; 997032d82d9SRoland McGrath } 998c269f196SRoland McGrath 999c269f196SRoland McGrath asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, 1000c269f196SRoland McGrath compat_long_t addr, compat_long_t data) 1001c269f196SRoland McGrath { 1002c269f196SRoland McGrath struct task_struct *child; 1003c269f196SRoland McGrath long ret; 1004c269f196SRoland McGrath 1005c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1006c269f196SRoland McGrath ret = ptrace_traceme(); 1007c269f196SRoland McGrath goto out; 1008c269f196SRoland McGrath } 1009c269f196SRoland McGrath 1010c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 1011c269f196SRoland McGrath if (IS_ERR(child)) { 1012c269f196SRoland McGrath ret = PTR_ERR(child); 1013c269f196SRoland McGrath goto out; 1014c269f196SRoland McGrath } 1015c269f196SRoland McGrath 10163544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 10173544d72aSTejun Heo ret = ptrace_attach(child, request, data); 1018c269f196SRoland McGrath /* 1019c269f196SRoland McGrath * Some architectures need to do book-keeping after 1020c269f196SRoland McGrath * a ptrace attach. 1021c269f196SRoland McGrath */ 1022c269f196SRoland McGrath if (!ret) 1023c269f196SRoland McGrath arch_ptrace_attach(child); 1024c269f196SRoland McGrath goto out_put_task_struct; 1025c269f196SRoland McGrath } 1026c269f196SRoland McGrath 1027fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1028fca26f26STejun Heo request == PTRACE_INTERRUPT); 1029c269f196SRoland McGrath if (!ret) 1030c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 1031c269f196SRoland McGrath 1032c269f196SRoland McGrath out_put_task_struct: 1033c269f196SRoland McGrath put_task_struct(child); 1034c269f196SRoland McGrath out: 1035c269f196SRoland McGrath return ret; 1036c269f196SRoland McGrath } 103796b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1038bf26c018SFrederic Weisbecker 1039bf26c018SFrederic Weisbecker #ifdef CONFIG_HAVE_HW_BREAKPOINT 1040bf26c018SFrederic Weisbecker int ptrace_get_breakpoints(struct task_struct *tsk) 1041bf26c018SFrederic Weisbecker { 1042bf26c018SFrederic Weisbecker if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) 1043bf26c018SFrederic Weisbecker return 0; 1044bf26c018SFrederic Weisbecker 1045bf26c018SFrederic Weisbecker return -1; 1046bf26c018SFrederic Weisbecker } 1047bf26c018SFrederic Weisbecker 1048bf26c018SFrederic Weisbecker void ptrace_put_breakpoints(struct task_struct *tsk) 1049bf26c018SFrederic Weisbecker { 1050bf26c018SFrederic Weisbecker if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) 1051bf26c018SFrederic Weisbecker flush_ptrace_hw_breakpoint(tsk); 1052bf26c018SFrederic Weisbecker } 1053bf26c018SFrederic Weisbecker #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 1054