1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * linux/kernel/ptrace.c 41da177e4SLinus Torvalds * 51da177e4SLinus Torvalds * (C) Copyright 1999 Linus Torvalds 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * Common interfaces for "ptrace()" which we do not want 81da177e4SLinus Torvalds * to continually duplicate across every architecture. 91da177e4SLinus Torvalds */ 101da177e4SLinus Torvalds 11c59ede7bSRandy.Dunlap #include <linux/capability.h> 129984de1aSPaul Gortmaker #include <linux/export.h> 131da177e4SLinus Torvalds #include <linux/sched.h> 146e84f315SIngo Molnar #include <linux/sched/mm.h> 15f7ccbae4SIngo Molnar #include <linux/sched/coredump.h> 1629930025SIngo Molnar #include <linux/sched/task.h> 171da177e4SLinus Torvalds #include <linux/errno.h> 181da177e4SLinus Torvalds #include <linux/mm.h> 191da177e4SLinus Torvalds #include <linux/highmem.h> 201da177e4SLinus Torvalds #include <linux/pagemap.h> 211da177e4SLinus Torvalds #include <linux/ptrace.h> 221da177e4SLinus Torvalds #include <linux/security.h> 237ed20e1aSJesper Juhl #include <linux/signal.h> 24a27bb332SKent Overstreet #include <linux/uio.h> 25a5cb013dSAl Viro #include <linux/audit.h> 26b488893aSPavel Emelyanov #include <linux/pid_namespace.h> 27f17d30a8SAdrian Bunk #include <linux/syscalls.h> 283a709703SRoland McGrath #include <linux/uaccess.h> 292225a122SSuresh Siddha #include <linux/regset.h> 30bf26c018SFrederic Weisbecker #include <linux/hw_breakpoint.h> 31f701e5b7SVladimir Zapolskiy #include <linux/cn_proc.h> 3284c751bdSAndrey Vagin #include <linux/compat.h> 33fcfc2aa0SAndrei Vagin #include <linux/sched/signal.h> 3490f093faSPiotr Figiel #include <linux/minmax.h> 351da177e4SLinus Torvalds 36201766a2SElvira Khabirova #include <asm/syscall.h> /* for syscall_get_* */ 37201766a2SElvira Khabirova 3884d77d3fSEric W. Biederman /* 3984d77d3fSEric W. Biederman * Access another process' address space via ptrace. 4084d77d3fSEric W. Biederman * Source/target buffer must be kernel space, 4184d77d3fSEric W. Biederman * Do not walk the page table directly, use get_user_pages 4284d77d3fSEric W. Biederman */ 4384d77d3fSEric W. Biederman int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, 4484d77d3fSEric W. Biederman void *buf, int len, unsigned int gup_flags) 4584d77d3fSEric W. Biederman { 4684d77d3fSEric W. Biederman struct mm_struct *mm; 4784d77d3fSEric W. Biederman int ret; 4884d77d3fSEric W. Biederman 4984d77d3fSEric W. Biederman mm = get_task_mm(tsk); 5084d77d3fSEric W. Biederman if (!mm) 5184d77d3fSEric W. Biederman return 0; 5284d77d3fSEric W. Biederman 5384d77d3fSEric W. Biederman if (!tsk->ptrace || 5484d77d3fSEric W. Biederman (current != tsk->parent) || 5584d77d3fSEric W. Biederman ((get_dumpable(mm) != SUID_DUMP_USER) && 5684d77d3fSEric W. Biederman !ptracer_capable(tsk, mm->user_ns))) { 5784d77d3fSEric W. Biederman mmput(mm); 5884d77d3fSEric W. Biederman return 0; 5984d77d3fSEric W. Biederman } 6084d77d3fSEric W. Biederman 61d3f5ffcaSJohn Hubbard ret = __access_remote_vm(mm, addr, buf, len, gup_flags); 6284d77d3fSEric W. Biederman mmput(mm); 6384d77d3fSEric W. Biederman 6484d77d3fSEric W. Biederman return ret; 6584d77d3fSEric W. Biederman } 6684d77d3fSEric W. Biederman 67bf53de90SMarkus Metzger 68c70d9d80SEric W. Biederman void __ptrace_link(struct task_struct *child, struct task_struct *new_parent, 69c70d9d80SEric W. Biederman const struct cred *ptracer_cred) 70c70d9d80SEric W. Biederman { 71c70d9d80SEric W. Biederman BUG_ON(!list_empty(&child->ptrace_entry)); 72c70d9d80SEric W. Biederman list_add(&child->ptrace_entry, &new_parent->ptraced); 73c70d9d80SEric W. Biederman child->parent = new_parent; 74c70d9d80SEric W. Biederman child->ptracer_cred = get_cred(ptracer_cred); 75c70d9d80SEric W. Biederman } 76c70d9d80SEric W. Biederman 77bf53de90SMarkus Metzger /* 781da177e4SLinus Torvalds * ptrace a task: make the debugger its new parent and 791da177e4SLinus Torvalds * move it to the ptrace list. 801da177e4SLinus Torvalds * 811da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 821da177e4SLinus Torvalds */ 83c70d9d80SEric W. Biederman static void ptrace_link(struct task_struct *child, struct task_struct *new_parent) 841da177e4SLinus Torvalds { 856994eefbSJann Horn __ptrace_link(child, new_parent, current_cred()); 861da177e4SLinus Torvalds } 871da177e4SLinus Torvalds 88e3bd058fSTejun Heo /** 89e3bd058fSTejun Heo * __ptrace_unlink - unlink ptracee and restore its execution state 90e3bd058fSTejun Heo * @child: ptracee to be unlinked 911da177e4SLinus Torvalds * 920e9f0a4aSTejun Heo * Remove @child from the ptrace list, move it back to the original parent, 930e9f0a4aSTejun Heo * and restore the execution state so that it conforms to the group stop 940e9f0a4aSTejun Heo * state. 950e9f0a4aSTejun Heo * 960e9f0a4aSTejun Heo * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer 970e9f0a4aSTejun Heo * exiting. For PTRACE_DETACH, unless the ptracee has been killed between 980e9f0a4aSTejun Heo * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. 990e9f0a4aSTejun Heo * If the ptracer is exiting, the ptracee can be in any state. 1000e9f0a4aSTejun Heo * 1010e9f0a4aSTejun Heo * After detach, the ptracee should be in a state which conforms to the 1020e9f0a4aSTejun Heo * group stop. If the group is stopped or in the process of stopping, the 1030e9f0a4aSTejun Heo * ptracee should be put into TASK_STOPPED; otherwise, it should be woken 1040e9f0a4aSTejun Heo * up from TASK_TRACED. 1050e9f0a4aSTejun Heo * 1060e9f0a4aSTejun Heo * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, 1070e9f0a4aSTejun Heo * it goes through TRACED -> RUNNING -> STOPPED transition which is similar 1080e9f0a4aSTejun Heo * to but in the opposite direction of what happens while attaching to a 1090e9f0a4aSTejun Heo * stopped task. However, in this direction, the intermediate RUNNING 1100e9f0a4aSTejun Heo * state is not hidden even from the current ptracer and if it immediately 1110e9f0a4aSTejun Heo * re-attaches and performs a WNOHANG wait(2), it may fail. 112e3bd058fSTejun Heo * 113e3bd058fSTejun Heo * CONTEXT: 114e3bd058fSTejun Heo * write_lock_irq(tasklist_lock) 1151da177e4SLinus Torvalds */ 11636c8b586SIngo Molnar void __ptrace_unlink(struct task_struct *child) 1171da177e4SLinus Torvalds { 11864b875f7SEric W. Biederman const struct cred *old_cred; 1195ecfbae0SOleg Nesterov BUG_ON(!child->ptrace); 1205ecfbae0SOleg Nesterov 12164c19ba2SGabriel Krisman Bertazi clear_task_syscall_work(child, SYSCALL_TRACE); 12264eb35f7SGabriel Krisman Bertazi #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) 12364eb35f7SGabriel Krisman Bertazi clear_task_syscall_work(child, SYSCALL_EMU); 12415532fd6SSudeep Holla #endif 1250a5bf409SAles Novak 1261da177e4SLinus Torvalds child->parent = child->real_parent; 127f470021aSRoland McGrath list_del_init(&child->ptrace_entry); 12864b875f7SEric W. Biederman old_cred = child->ptracer_cred; 12964b875f7SEric W. Biederman child->ptracer_cred = NULL; 13064b875f7SEric W. Biederman put_cred(old_cred); 1311da177e4SLinus Torvalds 1321da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 1331333ab03SOleg Nesterov child->ptrace = 0; 1341da177e4SLinus Torvalds /* 13573ddff2bSTejun Heo * Clear all pending traps and TRAPPING. TRAPPING should be 13673ddff2bSTejun Heo * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. 13773ddff2bSTejun Heo */ 13873ddff2bSTejun Heo task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); 13973ddff2bSTejun Heo task_clear_jobctl_trapping(child); 14073ddff2bSTejun Heo 14173ddff2bSTejun Heo /* 142a8f072c1STejun Heo * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and 1430e9f0a4aSTejun Heo * @child isn't dead. 1441da177e4SLinus Torvalds */ 1450e9f0a4aSTejun Heo if (!(child->flags & PF_EXITING) && 1460e9f0a4aSTejun Heo (child->signal->flags & SIGNAL_STOP_STOPPED || 1478a88951bSOleg Nesterov child->signal->group_stop_count)) { 148a8f072c1STejun Heo child->jobctl |= JOBCTL_STOP_PENDING; 1490e9f0a4aSTejun Heo 1500e9f0a4aSTejun Heo /* 1518a88951bSOleg Nesterov * This is only possible if this thread was cloned by the 1528a88951bSOleg Nesterov * traced task running in the stopped group, set the signal 1538a88951bSOleg Nesterov * for the future reports. 1548a88951bSOleg Nesterov * FIXME: we should change ptrace_init_task() to handle this 1558a88951bSOleg Nesterov * case. 1568a88951bSOleg Nesterov */ 1578a88951bSOleg Nesterov if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) 1588a88951bSOleg Nesterov child->jobctl |= SIGSTOP; 1598a88951bSOleg Nesterov } 1608a88951bSOleg Nesterov 1618a88951bSOleg Nesterov /* 1620e9f0a4aSTejun Heo * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick 1630e9f0a4aSTejun Heo * @child in the butt. Note that @resume should be used iff @child 1640e9f0a4aSTejun Heo * is in TASK_TRACED; otherwise, we might unduly disrupt 1650e9f0a4aSTejun Heo * TASK_KILLABLE sleeps. 1660e9f0a4aSTejun Heo */ 167a8f072c1STejun Heo if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) 168910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 1690e9f0a4aSTejun Heo 1701da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 1711da177e4SLinus Torvalds } 1721da177e4SLinus Torvalds 173dbb5afadSOleg Nesterov static bool looks_like_a_spurious_pid(struct task_struct *task) 174dbb5afadSOleg Nesterov { 175dbb5afadSOleg Nesterov if (task->exit_code != ((PTRACE_EVENT_EXEC << 8) | SIGTRAP)) 176dbb5afadSOleg Nesterov return false; 177dbb5afadSOleg Nesterov 178dbb5afadSOleg Nesterov if (task_pid_vnr(task) == task->ptrace_message) 179dbb5afadSOleg Nesterov return false; 180dbb5afadSOleg Nesterov /* 181dbb5afadSOleg Nesterov * The tracee changed its pid but the PTRACE_EVENT_EXEC event 182dbb5afadSOleg Nesterov * was not wait()'ed, most probably debugger targets the old 183dbb5afadSOleg Nesterov * leader which was destroyed in de_thread(). 184dbb5afadSOleg Nesterov */ 185dbb5afadSOleg Nesterov return true; 186dbb5afadSOleg Nesterov } 187dbb5afadSOleg Nesterov 1889899d11fSOleg Nesterov /* Ensure that nothing can wake it up, even SIGKILL */ 1899899d11fSOleg Nesterov static bool ptrace_freeze_traced(struct task_struct *task) 1909899d11fSOleg Nesterov { 1919899d11fSOleg Nesterov bool ret = false; 1929899d11fSOleg Nesterov 1939899d11fSOleg Nesterov /* Lockless, nobody but us can set this flag */ 1949899d11fSOleg Nesterov if (task->jobctl & JOBCTL_LISTENING) 1959899d11fSOleg Nesterov return ret; 1969899d11fSOleg Nesterov 1979899d11fSOleg Nesterov spin_lock_irq(&task->sighand->siglock); 198dbb5afadSOleg Nesterov if (task_is_traced(task) && !looks_like_a_spurious_pid(task) && 199dbb5afadSOleg Nesterov !__fatal_signal_pending(task)) { 200*2500ad1cSEric W. Biederman task->jobctl |= JOBCTL_PTRACE_FROZEN; 2019899d11fSOleg Nesterov ret = true; 2029899d11fSOleg Nesterov } 2039899d11fSOleg Nesterov spin_unlock_irq(&task->sighand->siglock); 2049899d11fSOleg Nesterov 2059899d11fSOleg Nesterov return ret; 2069899d11fSOleg Nesterov } 2079899d11fSOleg Nesterov 2089899d11fSOleg Nesterov static void ptrace_unfreeze_traced(struct task_struct *task) 2099899d11fSOleg Nesterov { 210*2500ad1cSEric W. Biederman unsigned long flags; 2119899d11fSOleg Nesterov 2125402e97aSbsegall@google.com /* 213*2500ad1cSEric W. Biederman * The child may be awake and may have cleared 214*2500ad1cSEric W. Biederman * JOBCTL_PTRACE_FROZEN (see ptrace_resume). The child will 215*2500ad1cSEric W. Biederman * not set JOBCTL_PTRACE_FROZEN or enter __TASK_TRACED anew. 2165402e97aSbsegall@google.com */ 217*2500ad1cSEric W. Biederman if (lock_task_sighand(task, &flags)) { 218*2500ad1cSEric W. Biederman task->jobctl &= ~JOBCTL_PTRACE_FROZEN; 2199899d11fSOleg Nesterov if (__fatal_signal_pending(task)) 2209899d11fSOleg Nesterov wake_up_state(task, __TASK_TRACED); 221*2500ad1cSEric W. Biederman unlock_task_sighand(task, &flags); 2225402e97aSbsegall@google.com } 2239899d11fSOleg Nesterov } 2249899d11fSOleg Nesterov 225755e276bSTejun Heo /** 226755e276bSTejun Heo * ptrace_check_attach - check whether ptracee is ready for ptrace operation 227755e276bSTejun Heo * @child: ptracee to check for 228755e276bSTejun Heo * @ignore_state: don't check whether @child is currently %TASK_TRACED 229755e276bSTejun Heo * 230755e276bSTejun Heo * Check whether @child is being ptraced by %current and ready for further 231755e276bSTejun Heo * ptrace operations. If @ignore_state is %false, @child also should be in 232755e276bSTejun Heo * %TASK_TRACED state and on return the child is guaranteed to be traced 233755e276bSTejun Heo * and not executing. If @ignore_state is %true, @child can be in any 234755e276bSTejun Heo * state. 235755e276bSTejun Heo * 236755e276bSTejun Heo * CONTEXT: 237755e276bSTejun Heo * Grabs and releases tasklist_lock and @child->sighand->siglock. 238755e276bSTejun Heo * 239755e276bSTejun Heo * RETURNS: 240755e276bSTejun Heo * 0 on success, -ESRCH if %child is not ready. 2411da177e4SLinus Torvalds */ 242edea0d03SOleg Nesterov static int ptrace_check_attach(struct task_struct *child, bool ignore_state) 2431da177e4SLinus Torvalds { 2441da177e4SLinus Torvalds int ret = -ESRCH; 2451da177e4SLinus Torvalds 2461da177e4SLinus Torvalds /* 2471da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 2481da177e4SLinus Torvalds * possible race where someone else was tracing our child and 2491da177e4SLinus Torvalds * detached between these two checks. After this locked check, 2501da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 2511da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 2521da177e4SLinus Torvalds */ 2531da177e4SLinus Torvalds read_lock(&tasklist_lock); 2549899d11fSOleg Nesterov if (child->ptrace && child->parent == current) { 255c0c0b649SOleg Nesterov /* 256c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 257c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 258c0c0b649SOleg Nesterov */ 2599899d11fSOleg Nesterov if (ignore_state || ptrace_freeze_traced(child)) 260321fb561SOleg Nesterov ret = 0; 2611da177e4SLinus Torvalds } 2621da177e4SLinus Torvalds read_unlock(&tasklist_lock); 2631da177e4SLinus Torvalds 2647b0fe136SEric W. Biederman if (!ret && !ignore_state && 2657b0fe136SEric W. Biederman WARN_ON_ONCE(!wait_task_inactive(child, __TASK_TRACED))) 2669899d11fSOleg Nesterov ret = -ESRCH; 2671da177e4SLinus Torvalds 2681da177e4SLinus Torvalds return ret; 2691da177e4SLinus Torvalds } 2701da177e4SLinus Torvalds 271cf237052SMickaël Salaün static bool ptrace_has_cap(struct user_namespace *ns, unsigned int mode) 27269f594a3SEric Paris { 27369f594a3SEric Paris if (mode & PTRACE_MODE_NOAUDIT) 274cf237052SMickaël Salaün return ns_capable_noaudit(ns, CAP_SYS_PTRACE); 275cf237052SMickaël Salaün return ns_capable(ns, CAP_SYS_PTRACE); 27669f594a3SEric Paris } 27769f594a3SEric Paris 2789f99798fSTetsuo Handa /* Returns 0 on success, -errno on denial. */ 2799f99798fSTetsuo Handa static int __ptrace_may_access(struct task_struct *task, unsigned int mode) 280ab8d11beSMiklos Szeredi { 281c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 282bfedb589SEric W. Biederman struct mm_struct *mm; 283caaee623SJann Horn kuid_t caller_uid; 284caaee623SJann Horn kgid_t caller_gid; 285caaee623SJann Horn 286caaee623SJann Horn if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { 287caaee623SJann Horn WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); 288caaee623SJann Horn return -EPERM; 289caaee623SJann Horn } 290b6dff3ecSDavid Howells 291df26c40eSEric W. Biederman /* May we inspect the given task? 292df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 293df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 294df26c40eSEric W. Biederman * 295df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 296df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 297df26c40eSEric W. Biederman * or halting the specified task is impossible. 298df26c40eSEric W. Biederman */ 299caaee623SJann Horn 300df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 30173af963fSMark Grondona if (same_thread_group(task, current)) 302df26c40eSEric W. Biederman return 0; 303c69e8d9cSDavid Howells rcu_read_lock(); 304caaee623SJann Horn if (mode & PTRACE_MODE_FSCREDS) { 305caaee623SJann Horn caller_uid = cred->fsuid; 306caaee623SJann Horn caller_gid = cred->fsgid; 307caaee623SJann Horn } else { 308caaee623SJann Horn /* 309caaee623SJann Horn * Using the euid would make more sense here, but something 310caaee623SJann Horn * in userland might rely on the old behavior, and this 311caaee623SJann Horn * shouldn't be a security problem since 312caaee623SJann Horn * PTRACE_MODE_REALCREDS implies that the caller explicitly 313caaee623SJann Horn * used a syscall that requests access to another process 314caaee623SJann Horn * (and not a filesystem syscall to procfs). 315caaee623SJann Horn */ 316caaee623SJann Horn caller_uid = cred->uid; 317caaee623SJann Horn caller_gid = cred->gid; 318caaee623SJann Horn } 319c69e8d9cSDavid Howells tcred = __task_cred(task); 320caaee623SJann Horn if (uid_eq(caller_uid, tcred->euid) && 321caaee623SJann Horn uid_eq(caller_uid, tcred->suid) && 322caaee623SJann Horn uid_eq(caller_uid, tcred->uid) && 323caaee623SJann Horn gid_eq(caller_gid, tcred->egid) && 324caaee623SJann Horn gid_eq(caller_gid, tcred->sgid) && 325caaee623SJann Horn gid_eq(caller_gid, tcred->gid)) 3268409cca7SSerge E. Hallyn goto ok; 327cf237052SMickaël Salaün if (ptrace_has_cap(tcred->user_ns, mode)) 3288409cca7SSerge E. Hallyn goto ok; 329c69e8d9cSDavid Howells rcu_read_unlock(); 330ab8d11beSMiklos Szeredi return -EPERM; 3318409cca7SSerge E. Hallyn ok: 332c69e8d9cSDavid Howells rcu_read_unlock(); 333f6581f5bSJann Horn /* 334f6581f5bSJann Horn * If a task drops privileges and becomes nondumpable (through a syscall 335f6581f5bSJann Horn * like setresuid()) while we are trying to access it, we must ensure 336f6581f5bSJann Horn * that the dumpability is read after the credentials; otherwise, 337f6581f5bSJann Horn * we may be able to attach to a task that we shouldn't be able to 338f6581f5bSJann Horn * attach to (as if the task had dropped privileges without becoming 339f6581f5bSJann Horn * nondumpable). 340f6581f5bSJann Horn * Pairs with a write barrier in commit_creds(). 341f6581f5bSJann Horn */ 342f6581f5bSJann Horn smp_rmb(); 343bfedb589SEric W. Biederman mm = task->mm; 344bfedb589SEric W. Biederman if (mm && 345bfedb589SEric W. Biederman ((get_dumpable(mm) != SUID_DUMP_USER) && 346cf237052SMickaël Salaün !ptrace_has_cap(mm->user_ns, mode))) 347ab8d11beSMiklos Szeredi return -EPERM; 348ab8d11beSMiklos Szeredi 3499e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 350ab8d11beSMiklos Szeredi } 351ab8d11beSMiklos Szeredi 352006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 353ab8d11beSMiklos Szeredi { 354ab8d11beSMiklos Szeredi int err; 355ab8d11beSMiklos Szeredi task_lock(task); 356006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 357ab8d11beSMiklos Szeredi task_unlock(task); 3583a709703SRoland McGrath return !err; 359ab8d11beSMiklos Szeredi } 360ab8d11beSMiklos Szeredi 361ee1fee90SJann Horn static int check_ptrace_options(unsigned long data) 362ee1fee90SJann Horn { 363ee1fee90SJann Horn if (data & ~(unsigned long)PTRACE_O_MASK) 364ee1fee90SJann Horn return -EINVAL; 365ee1fee90SJann Horn 366ee1fee90SJann Horn if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { 367ee1fee90SJann Horn if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || 368ee1fee90SJann Horn !IS_ENABLED(CONFIG_SECCOMP)) 369ee1fee90SJann Horn return -EINVAL; 370ee1fee90SJann Horn 371ee1fee90SJann Horn if (!capable(CAP_SYS_ADMIN)) 372ee1fee90SJann Horn return -EPERM; 373ee1fee90SJann Horn 374ee1fee90SJann Horn if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || 375ee1fee90SJann Horn current->ptrace & PT_SUSPEND_SECCOMP) 376ee1fee90SJann Horn return -EPERM; 377ee1fee90SJann Horn } 378ee1fee90SJann Horn return 0; 379ee1fee90SJann Horn } 380ee1fee90SJann Horn 3813544d72aSTejun Heo static int ptrace_attach(struct task_struct *task, long request, 382aa9147c9SDenys Vlasenko unsigned long addr, 3833544d72aSTejun Heo unsigned long flags) 3841da177e4SLinus Torvalds { 3853544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 3861da177e4SLinus Torvalds int retval; 387f5b40e36SLinus Torvalds 3883544d72aSTejun Heo retval = -EIO; 389aa9147c9SDenys Vlasenko if (seize) { 390aa9147c9SDenys Vlasenko if (addr != 0) 3913544d72aSTejun Heo goto out; 392ee1fee90SJann Horn /* 393ee1fee90SJann Horn * This duplicates the check in check_ptrace_options() because 394ee1fee90SJann Horn * ptrace_attach() and ptrace_setoptions() have historically 395ee1fee90SJann Horn * used different error codes for unknown ptrace options. 396ee1fee90SJann Horn */ 397aa9147c9SDenys Vlasenko if (flags & ~(unsigned long)PTRACE_O_MASK) 398aa9147c9SDenys Vlasenko goto out; 399ee1fee90SJann Horn retval = check_ptrace_options(flags); 400ee1fee90SJann Horn if (retval) 401ee1fee90SJann Horn return retval; 402aa9147c9SDenys Vlasenko flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); 403aa9147c9SDenys Vlasenko } else { 404aa9147c9SDenys Vlasenko flags = PT_PTRACED; 405aa9147c9SDenys Vlasenko } 4063544d72aSTejun Heo 407a5cb013dSAl Viro audit_ptrace(task); 408a5cb013dSAl Viro 4091da177e4SLinus Torvalds retval = -EPERM; 410e8b33b8cSJens Axboe if (unlikely(task->flags & PF_KTHREAD)) 411b79b7ba9SOleg Nesterov goto out; 412bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 413f5b40e36SLinus Torvalds goto out; 414f5b40e36SLinus Torvalds 415f2f0b00aSOleg Nesterov /* 416f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 41786b6c1f3SDenys Vlasenko * SUID, SGID and LSM creds get determined differently 4185e751e99SDavid Howells * under ptrace. 419d84f4f99SDavid Howells */ 420793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 4219b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 422d84f4f99SDavid Howells goto out; 4234b105cbbSOleg Nesterov 424f5b40e36SLinus Torvalds task_lock(task); 425caaee623SJann Horn retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); 4264b105cbbSOleg Nesterov task_unlock(task); 4271da177e4SLinus Torvalds if (retval) 4284b105cbbSOleg Nesterov goto unlock_creds; 4291da177e4SLinus Torvalds 4304b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 431b79b7ba9SOleg Nesterov retval = -EPERM; 432b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 4334b105cbbSOleg Nesterov goto unlock_tasklist; 434f2f0b00aSOleg Nesterov if (task->ptrace) 4354b105cbbSOleg Nesterov goto unlock_tasklist; 436b79b7ba9SOleg Nesterov 437aa9147c9SDenys Vlasenko task->ptrace = flags; 4381da177e4SLinus Torvalds 439c70d9d80SEric W. Biederman ptrace_link(task, current); 4403544d72aSTejun Heo 4413544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 4423544d72aSTejun Heo if (!seize) 443079b22dcSEric W. Biederman send_sig_info(SIGSTOP, SEND_SIG_PRIV, task); 444b79b7ba9SOleg Nesterov 445d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 446d79fdd6dSTejun Heo 447d79fdd6dSTejun Heo /* 44873ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 449d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 450d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 451d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 452d79fdd6dSTejun Heo * for the transition to complete before returning from this 453d79fdd6dSTejun Heo * function. 454d79fdd6dSTejun Heo * 455d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 456d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 457d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 458d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 459d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 460d79fdd6dSTejun Heo * 461d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 462d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 463d79fdd6dSTejun Heo */ 4647dd3db54STejun Heo if (task_is_stopped(task) && 46573ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 466910ffdb1SOleg Nesterov signal_wake_up_state(task, __TASK_STOPPED); 467d79fdd6dSTejun Heo 468d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 469d79fdd6dSTejun Heo 470b79b7ba9SOleg Nesterov retval = 0; 4714b105cbbSOleg Nesterov unlock_tasklist: 4724b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 4734b105cbbSOleg Nesterov unlock_creds: 4749b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 475f5b40e36SLinus Torvalds out: 476f701e5b7SVladimir Zapolskiy if (!retval) { 4777c3b00e0SOleg Nesterov /* 4787c3b00e0SOleg Nesterov * We do not bother to change retval or clear JOBCTL_TRAPPING 4797c3b00e0SOleg Nesterov * if wait_on_bit() was interrupted by SIGKILL. The tracer will 4807c3b00e0SOleg Nesterov * not return to user-mode, it will exit and clear this bit in 4817c3b00e0SOleg Nesterov * __ptrace_unlink() if it wasn't already cleared by the tracee; 4827c3b00e0SOleg Nesterov * and until then nobody can ptrace this task. 4837c3b00e0SOleg Nesterov */ 4847c3b00e0SOleg Nesterov wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); 485f701e5b7SVladimir Zapolskiy proc_ptrace_connector(task, PTRACE_ATTACH); 486f701e5b7SVladimir Zapolskiy } 487f701e5b7SVladimir Zapolskiy 4881da177e4SLinus Torvalds return retval; 4891da177e4SLinus Torvalds } 4901da177e4SLinus Torvalds 491f2f0b00aSOleg Nesterov /** 492f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 493f2f0b00aSOleg Nesterov * 494f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 495f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 496f2f0b00aSOleg Nesterov */ 497e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 498f2f0b00aSOleg Nesterov { 499f2f0b00aSOleg Nesterov int ret = -EPERM; 500f2f0b00aSOleg Nesterov 5014b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 5024b105cbbSOleg Nesterov /* Are we already being traced? */ 503f2f0b00aSOleg Nesterov if (!current->ptrace) { 504f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 505f2f0b00aSOleg Nesterov /* 506f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 507f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 508f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 509f2f0b00aSOleg Nesterov */ 510f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 511f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 512c70d9d80SEric W. Biederman ptrace_link(current, current->real_parent); 513f2f0b00aSOleg Nesterov } 514f2f0b00aSOleg Nesterov } 5154b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 5164b105cbbSOleg Nesterov 517f2f0b00aSOleg Nesterov return ret; 518f2f0b00aSOleg Nesterov } 519f2f0b00aSOleg Nesterov 52039c626aeSOleg Nesterov /* 52139c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 52239c626aeSOleg Nesterov */ 52339c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 52439c626aeSOleg Nesterov { 52539c626aeSOleg Nesterov int ret; 52639c626aeSOleg Nesterov spin_lock(&sigh->siglock); 52739c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 52839c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 52939c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 53039c626aeSOleg Nesterov return ret; 53139c626aeSOleg Nesterov } 53239c626aeSOleg Nesterov 53339c626aeSOleg Nesterov /* 53439c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 53539c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 53639c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 53739c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 53839c626aeSOleg Nesterov * 53939c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 54039c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 54139c626aeSOleg Nesterov * If it should reap itself, return true. 54239c626aeSOleg Nesterov * 543a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 544a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 545a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 546a7f0765eSOleg Nesterov * do_wait(). 54739c626aeSOleg Nesterov */ 54839c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 54939c626aeSOleg Nesterov { 5509843a1e9SOleg Nesterov bool dead; 5519843a1e9SOleg Nesterov 55239c626aeSOleg Nesterov __ptrace_unlink(p); 55339c626aeSOleg Nesterov 5549843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 5559843a1e9SOleg Nesterov return false; 5569843a1e9SOleg Nesterov 5579843a1e9SOleg Nesterov dead = !thread_group_leader(p); 5589843a1e9SOleg Nesterov 5599843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 56039c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 5619843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 562a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 563a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 5649843a1e9SOleg Nesterov dead = true; 56539c626aeSOleg Nesterov } 566a7f0765eSOleg Nesterov } 56739c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 5689843a1e9SOleg Nesterov if (dead) 56939c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 5709843a1e9SOleg Nesterov return dead; 57139c626aeSOleg Nesterov } 57239c626aeSOleg Nesterov 573e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 5741da177e4SLinus Torvalds { 5757ed20e1aSJesper Juhl if (!valid_signal(data)) 5761da177e4SLinus Torvalds return -EIO; 5771da177e4SLinus Torvalds 5781da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 5791da177e4SLinus Torvalds ptrace_disable(child); 5801da177e4SLinus Torvalds 58195c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 58239c626aeSOleg Nesterov /* 58364a4096cSOleg Nesterov * We rely on ptrace_freeze_traced(). It can't be killed and 58464a4096cSOleg Nesterov * untraced by another thread, it can't be a zombie. 58539c626aeSOleg Nesterov */ 58664a4096cSOleg Nesterov WARN_ON(!child->ptrace || child->exit_state); 58764a4096cSOleg Nesterov /* 58864a4096cSOleg Nesterov * tasklist_lock avoids the race with wait_task_stopped(), see 58964a4096cSOleg Nesterov * the comment in ptrace_resume(). 59064a4096cSOleg Nesterov */ 59195c3eb76SOleg Nesterov child->exit_code = data; 59264a4096cSOleg Nesterov __ptrace_detach(current, child); 5931da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 5941da177e4SLinus Torvalds 595f701e5b7SVladimir Zapolskiy proc_ptrace_connector(child, PTRACE_DETACH); 5964576145cSOleg Nesterov 5971da177e4SLinus Torvalds return 0; 5981da177e4SLinus Torvalds } 5991da177e4SLinus Torvalds 60039c626aeSOleg Nesterov /* 601c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 6027c8bd232SOleg Nesterov * for writing. 60339c626aeSOleg Nesterov */ 6047c8bd232SOleg Nesterov void exit_ptrace(struct task_struct *tracer, struct list_head *dead) 60539c626aeSOleg Nesterov { 60639c626aeSOleg Nesterov struct task_struct *p, *n; 607c7e49c14SOleg Nesterov 60839c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 609992fb6e1SOleg Nesterov if (unlikely(p->ptrace & PT_EXITKILL)) 610079b22dcSEric W. Biederman send_sig_info(SIGKILL, SEND_SIG_PRIV, p); 611992fb6e1SOleg Nesterov 61239c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 6137c8bd232SOleg Nesterov list_add(&p->ptrace_entry, dead); 61439c626aeSOleg Nesterov } 61539c626aeSOleg Nesterov } 61639c626aeSOleg Nesterov 6171da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 6181da177e4SLinus Torvalds { 6191da177e4SLinus Torvalds int copied = 0; 6201da177e4SLinus Torvalds 6211da177e4SLinus Torvalds while (len > 0) { 6221da177e4SLinus Torvalds char buf[128]; 6231da177e4SLinus Torvalds int this_len, retval; 6241da177e4SLinus Torvalds 6251da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 62684d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE); 62784d77d3fSEric W. Biederman 6281da177e4SLinus Torvalds if (!retval) { 6291da177e4SLinus Torvalds if (copied) 6301da177e4SLinus Torvalds break; 6311da177e4SLinus Torvalds return -EIO; 6321da177e4SLinus Torvalds } 6331da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 6341da177e4SLinus Torvalds return -EFAULT; 6351da177e4SLinus Torvalds copied += retval; 6361da177e4SLinus Torvalds src += retval; 6371da177e4SLinus Torvalds dst += retval; 6381da177e4SLinus Torvalds len -= retval; 6391da177e4SLinus Torvalds } 6401da177e4SLinus Torvalds return copied; 6411da177e4SLinus Torvalds } 6421da177e4SLinus Torvalds 6431da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 6441da177e4SLinus Torvalds { 6451da177e4SLinus Torvalds int copied = 0; 6461da177e4SLinus Torvalds 6471da177e4SLinus Torvalds while (len > 0) { 6481da177e4SLinus Torvalds char buf[128]; 6491da177e4SLinus Torvalds int this_len, retval; 6501da177e4SLinus Torvalds 6511da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 6521da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 6531da177e4SLinus Torvalds return -EFAULT; 65484d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, dst, buf, this_len, 655f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 6561da177e4SLinus Torvalds if (!retval) { 6571da177e4SLinus Torvalds if (copied) 6581da177e4SLinus Torvalds break; 6591da177e4SLinus Torvalds return -EIO; 6601da177e4SLinus Torvalds } 6611da177e4SLinus Torvalds copied += retval; 6621da177e4SLinus Torvalds src += retval; 6631da177e4SLinus Torvalds dst += retval; 6641da177e4SLinus Torvalds len -= retval; 6651da177e4SLinus Torvalds } 6661da177e4SLinus Torvalds return copied; 6671da177e4SLinus Torvalds } 6681da177e4SLinus Torvalds 6694abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 6701da177e4SLinus Torvalds { 67186b6c1f3SDenys Vlasenko unsigned flags; 672ee1fee90SJann Horn int ret; 67386b6c1f3SDenys Vlasenko 674ee1fee90SJann Horn ret = check_ptrace_options(data); 675ee1fee90SJann Horn if (ret) 676ee1fee90SJann Horn return ret; 67713c4a901STycho Andersen 67886b6c1f3SDenys Vlasenko /* Avoid intermediate state when all opts are cleared */ 67986b6c1f3SDenys Vlasenko flags = child->ptrace; 68086b6c1f3SDenys Vlasenko flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); 68186b6c1f3SDenys Vlasenko flags |= (data << PT_OPT_FLAG_SHIFT); 68286b6c1f3SDenys Vlasenko child->ptrace = flags; 6831da177e4SLinus Torvalds 6848c5cf9e5SDenys Vlasenko return 0; 6851da177e4SLinus Torvalds } 6861da177e4SLinus Torvalds 687ae7795bcSEric W. Biederman static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info) 6881da177e4SLinus Torvalds { 689e4961254SOleg Nesterov unsigned long flags; 6901da177e4SLinus Torvalds int error = -ESRCH; 6911da177e4SLinus Torvalds 692e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 6931da177e4SLinus Torvalds error = -EINVAL; 6941da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 6950752d7bfSEric W. Biederman copy_siginfo(info, child->last_siginfo); 6961da177e4SLinus Torvalds error = 0; 6971da177e4SLinus Torvalds } 698e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 6991da177e4SLinus Torvalds } 7001da177e4SLinus Torvalds return error; 7011da177e4SLinus Torvalds } 7021da177e4SLinus Torvalds 703ae7795bcSEric W. Biederman static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info) 7041da177e4SLinus Torvalds { 705e4961254SOleg Nesterov unsigned long flags; 7061da177e4SLinus Torvalds int error = -ESRCH; 7071da177e4SLinus Torvalds 708e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 7091da177e4SLinus Torvalds error = -EINVAL; 7101da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 7110752d7bfSEric W. Biederman copy_siginfo(child->last_siginfo, info); 7121da177e4SLinus Torvalds error = 0; 7131da177e4SLinus Torvalds } 714e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 7151da177e4SLinus Torvalds } 7161da177e4SLinus Torvalds return error; 7171da177e4SLinus Torvalds } 7181da177e4SLinus Torvalds 71984c751bdSAndrey Vagin static int ptrace_peek_siginfo(struct task_struct *child, 72084c751bdSAndrey Vagin unsigned long addr, 72184c751bdSAndrey Vagin unsigned long data) 72284c751bdSAndrey Vagin { 72384c751bdSAndrey Vagin struct ptrace_peeksiginfo_args arg; 72484c751bdSAndrey Vagin struct sigpending *pending; 72584c751bdSAndrey Vagin struct sigqueue *q; 72684c751bdSAndrey Vagin int ret, i; 72784c751bdSAndrey Vagin 72884c751bdSAndrey Vagin ret = copy_from_user(&arg, (void __user *) addr, 72984c751bdSAndrey Vagin sizeof(struct ptrace_peeksiginfo_args)); 73084c751bdSAndrey Vagin if (ret) 73184c751bdSAndrey Vagin return -EFAULT; 73284c751bdSAndrey Vagin 73384c751bdSAndrey Vagin if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) 73484c751bdSAndrey Vagin return -EINVAL; /* unknown flags */ 73584c751bdSAndrey Vagin 73684c751bdSAndrey Vagin if (arg.nr < 0) 73784c751bdSAndrey Vagin return -EINVAL; 73884c751bdSAndrey Vagin 739f6e2aa91SEric W. Biederman /* Ensure arg.off fits in an unsigned long */ 740f6e2aa91SEric W. Biederman if (arg.off > ULONG_MAX) 741f6e2aa91SEric W. Biederman return 0; 742f6e2aa91SEric W. Biederman 74384c751bdSAndrey Vagin if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) 74484c751bdSAndrey Vagin pending = &child->signal->shared_pending; 74584c751bdSAndrey Vagin else 74684c751bdSAndrey Vagin pending = &child->pending; 74784c751bdSAndrey Vagin 74884c751bdSAndrey Vagin for (i = 0; i < arg.nr; ) { 749ae7795bcSEric W. Biederman kernel_siginfo_t info; 750f6e2aa91SEric W. Biederman unsigned long off = arg.off + i; 751f6e2aa91SEric W. Biederman bool found = false; 75284c751bdSAndrey Vagin 75384c751bdSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 75484c751bdSAndrey Vagin list_for_each_entry(q, &pending->list, list) { 75584c751bdSAndrey Vagin if (!off--) { 756f6e2aa91SEric W. Biederman found = true; 75784c751bdSAndrey Vagin copy_siginfo(&info, &q->info); 75884c751bdSAndrey Vagin break; 75984c751bdSAndrey Vagin } 76084c751bdSAndrey Vagin } 76184c751bdSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 76284c751bdSAndrey Vagin 763f6e2aa91SEric W. Biederman if (!found) /* beyond the end of the list */ 76484c751bdSAndrey Vagin break; 76584c751bdSAndrey Vagin 76684c751bdSAndrey Vagin #ifdef CONFIG_COMPAT 7675c465217SAndy Lutomirski if (unlikely(in_compat_syscall())) { 76884c751bdSAndrey Vagin compat_siginfo_t __user *uinfo = compat_ptr(data); 76984c751bdSAndrey Vagin 770cc731525SEric W. Biederman if (copy_siginfo_to_user32(uinfo, &info)) { 771706b23bdSMathieu Desnoyers ret = -EFAULT; 772706b23bdSMathieu Desnoyers break; 773706b23bdSMathieu Desnoyers } 774706b23bdSMathieu Desnoyers 77584c751bdSAndrey Vagin } else 77684c751bdSAndrey Vagin #endif 77784c751bdSAndrey Vagin { 77884c751bdSAndrey Vagin siginfo_t __user *uinfo = (siginfo_t __user *) data; 77984c751bdSAndrey Vagin 780cc731525SEric W. Biederman if (copy_siginfo_to_user(uinfo, &info)) { 78184c751bdSAndrey Vagin ret = -EFAULT; 78284c751bdSAndrey Vagin break; 78384c751bdSAndrey Vagin } 784706b23bdSMathieu Desnoyers } 78584c751bdSAndrey Vagin 78684c751bdSAndrey Vagin data += sizeof(siginfo_t); 78784c751bdSAndrey Vagin i++; 78884c751bdSAndrey Vagin 78984c751bdSAndrey Vagin if (signal_pending(current)) 79084c751bdSAndrey Vagin break; 79184c751bdSAndrey Vagin 79284c751bdSAndrey Vagin cond_resched(); 79384c751bdSAndrey Vagin } 79484c751bdSAndrey Vagin 79584c751bdSAndrey Vagin if (i > 0) 79684c751bdSAndrey Vagin return i; 79784c751bdSAndrey Vagin 79884c751bdSAndrey Vagin return ret; 79984c751bdSAndrey Vagin } 80036df29d7SRoland McGrath 80190f093faSPiotr Figiel #ifdef CONFIG_RSEQ 80290f093faSPiotr Figiel static long ptrace_get_rseq_configuration(struct task_struct *task, 80390f093faSPiotr Figiel unsigned long size, void __user *data) 80490f093faSPiotr Figiel { 80590f093faSPiotr Figiel struct ptrace_rseq_configuration conf = { 80690f093faSPiotr Figiel .rseq_abi_pointer = (u64)(uintptr_t)task->rseq, 80790f093faSPiotr Figiel .rseq_abi_size = sizeof(*task->rseq), 80890f093faSPiotr Figiel .signature = task->rseq_sig, 80990f093faSPiotr Figiel .flags = 0, 81090f093faSPiotr Figiel }; 81190f093faSPiotr Figiel 81290f093faSPiotr Figiel size = min_t(unsigned long, size, sizeof(conf)); 81390f093faSPiotr Figiel if (copy_to_user(data, &conf, size)) 81490f093faSPiotr Figiel return -EFAULT; 81590f093faSPiotr Figiel return sizeof(conf); 81690f093faSPiotr Figiel } 81790f093faSPiotr Figiel #endif 81890f093faSPiotr Figiel 81936df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 82036df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 82136df29d7SRoland McGrath #else 82236df29d7SRoland McGrath #define is_singlestep(request) 0 82336df29d7SRoland McGrath #endif 82436df29d7SRoland McGrath 8255b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 8265b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 8275b88abbfSRoland McGrath #else 8285b88abbfSRoland McGrath #define is_singleblock(request) 0 8295b88abbfSRoland McGrath #endif 8305b88abbfSRoland McGrath 83136df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 83236df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 83336df29d7SRoland McGrath #else 83436df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 83536df29d7SRoland McGrath #endif 83636df29d7SRoland McGrath 8374abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 8384abf9869SNamhyung Kim unsigned long data) 83936df29d7SRoland McGrath { 840b72c1869SOleg Nesterov bool need_siglock; 841b72c1869SOleg Nesterov 84236df29d7SRoland McGrath if (!valid_signal(data)) 84336df29d7SRoland McGrath return -EIO; 84436df29d7SRoland McGrath 84536df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 84664c19ba2SGabriel Krisman Bertazi set_task_syscall_work(child, SYSCALL_TRACE); 84736df29d7SRoland McGrath else 84864c19ba2SGabriel Krisman Bertazi clear_task_syscall_work(child, SYSCALL_TRACE); 84936df29d7SRoland McGrath 85064eb35f7SGabriel Krisman Bertazi #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) 85136df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 85264eb35f7SGabriel Krisman Bertazi set_task_syscall_work(child, SYSCALL_EMU); 85336df29d7SRoland McGrath else 85464eb35f7SGabriel Krisman Bertazi clear_task_syscall_work(child, SYSCALL_EMU); 85536df29d7SRoland McGrath #endif 85636df29d7SRoland McGrath 8575b88abbfSRoland McGrath if (is_singleblock(request)) { 8585b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 8595b88abbfSRoland McGrath return -EIO; 8605b88abbfSRoland McGrath user_enable_block_step(child); 8615b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 86236df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 86336df29d7SRoland McGrath return -EIO; 86436df29d7SRoland McGrath user_enable_single_step(child); 8653a709703SRoland McGrath } else { 86636df29d7SRoland McGrath user_disable_single_step(child); 8673a709703SRoland McGrath } 86836df29d7SRoland McGrath 869b72c1869SOleg Nesterov /* 870b72c1869SOleg Nesterov * Change ->exit_code and ->state under siglock to avoid the race 871b72c1869SOleg Nesterov * with wait_task_stopped() in between; a non-zero ->exit_code will 872b72c1869SOleg Nesterov * wrongly look like another report from tracee. 873b72c1869SOleg Nesterov * 874b72c1869SOleg Nesterov * Note that we need siglock even if ->exit_code == data and/or this 875b72c1869SOleg Nesterov * status was not reported yet, the new status must not be cleared by 876b72c1869SOleg Nesterov * wait_task_stopped() after resume. 877b72c1869SOleg Nesterov * 878b72c1869SOleg Nesterov * If data == 0 we do not care if wait_task_stopped() reports the old 879b72c1869SOleg Nesterov * status and clears the code too; this can't race with the tracee, it 880b72c1869SOleg Nesterov * takes siglock after resume. 881b72c1869SOleg Nesterov */ 882b72c1869SOleg Nesterov need_siglock = data && !thread_group_empty(current); 883b72c1869SOleg Nesterov if (need_siglock) 884b72c1869SOleg Nesterov spin_lock_irq(&child->sighand->siglock); 88536df29d7SRoland McGrath child->exit_code = data; 8860666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 887b72c1869SOleg Nesterov if (need_siglock) 888b72c1869SOleg Nesterov spin_unlock_irq(&child->sighand->siglock); 88936df29d7SRoland McGrath 89036df29d7SRoland McGrath return 0; 89136df29d7SRoland McGrath } 89236df29d7SRoland McGrath 8932225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8942225a122SSuresh Siddha 8952225a122SSuresh Siddha static const struct user_regset * 8962225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 8972225a122SSuresh Siddha { 8982225a122SSuresh Siddha const struct user_regset *regset; 8992225a122SSuresh Siddha int n; 9002225a122SSuresh Siddha 9012225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 9022225a122SSuresh Siddha regset = view->regsets + n; 9032225a122SSuresh Siddha if (regset->core_note_type == type) 9042225a122SSuresh Siddha return regset; 9052225a122SSuresh Siddha } 9062225a122SSuresh Siddha 9072225a122SSuresh Siddha return NULL; 9082225a122SSuresh Siddha } 9092225a122SSuresh Siddha 9102225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 9112225a122SSuresh Siddha struct iovec *kiov) 9122225a122SSuresh Siddha { 9132225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 9142225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 9152225a122SSuresh Siddha int regset_no; 9162225a122SSuresh Siddha 9172225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 918c6a0dd7eSSuresh Siddha return -EINVAL; 9192225a122SSuresh Siddha 9202225a122SSuresh Siddha regset_no = regset - view->regsets; 9212225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 9222225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 9232225a122SSuresh Siddha 9242225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 9252225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 9262225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 9272225a122SSuresh Siddha else 9282225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 9292225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 9302225a122SSuresh Siddha } 9312225a122SSuresh Siddha 932e8440c14SJosh Stone /* 933e8440c14SJosh Stone * This is declared in linux/regset.h and defined in machine-dependent 934e8440c14SJosh Stone * code. We put the export here, near the primary machine-neutral use, 935e8440c14SJosh Stone * to ensure no machine forgets it. 936e8440c14SJosh Stone */ 937e8440c14SJosh Stone EXPORT_SYMBOL_GPL(task_user_regset_view); 938201766a2SElvira Khabirova 939201766a2SElvira Khabirova static unsigned long 940201766a2SElvira Khabirova ptrace_get_syscall_info_entry(struct task_struct *child, struct pt_regs *regs, 941201766a2SElvira Khabirova struct ptrace_syscall_info *info) 942201766a2SElvira Khabirova { 943201766a2SElvira Khabirova unsigned long args[ARRAY_SIZE(info->entry.args)]; 944201766a2SElvira Khabirova int i; 945201766a2SElvira Khabirova 946201766a2SElvira Khabirova info->op = PTRACE_SYSCALL_INFO_ENTRY; 947201766a2SElvira Khabirova info->entry.nr = syscall_get_nr(child, regs); 948201766a2SElvira Khabirova syscall_get_arguments(child, regs, args); 949201766a2SElvira Khabirova for (i = 0; i < ARRAY_SIZE(args); i++) 950201766a2SElvira Khabirova info->entry.args[i] = args[i]; 951201766a2SElvira Khabirova 952201766a2SElvira Khabirova /* args is the last field in struct ptrace_syscall_info.entry */ 953201766a2SElvira Khabirova return offsetofend(struct ptrace_syscall_info, entry.args); 954201766a2SElvira Khabirova } 955201766a2SElvira Khabirova 956201766a2SElvira Khabirova static unsigned long 957201766a2SElvira Khabirova ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs, 958201766a2SElvira Khabirova struct ptrace_syscall_info *info) 959201766a2SElvira Khabirova { 960201766a2SElvira Khabirova /* 961201766a2SElvira Khabirova * As struct ptrace_syscall_info.entry is currently a subset 962201766a2SElvira Khabirova * of struct ptrace_syscall_info.seccomp, it makes sense to 963201766a2SElvira Khabirova * initialize that subset using ptrace_get_syscall_info_entry(). 964201766a2SElvira Khabirova * This can be reconsidered in the future if these structures 965201766a2SElvira Khabirova * diverge significantly enough. 966201766a2SElvira Khabirova */ 967201766a2SElvira Khabirova ptrace_get_syscall_info_entry(child, regs, info); 968201766a2SElvira Khabirova info->op = PTRACE_SYSCALL_INFO_SECCOMP; 969201766a2SElvira Khabirova info->seccomp.ret_data = child->ptrace_message; 970201766a2SElvira Khabirova 971201766a2SElvira Khabirova /* ret_data is the last field in struct ptrace_syscall_info.seccomp */ 972201766a2SElvira Khabirova return offsetofend(struct ptrace_syscall_info, seccomp.ret_data); 973201766a2SElvira Khabirova } 974201766a2SElvira Khabirova 975201766a2SElvira Khabirova static unsigned long 976201766a2SElvira Khabirova ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs, 977201766a2SElvira Khabirova struct ptrace_syscall_info *info) 978201766a2SElvira Khabirova { 979201766a2SElvira Khabirova info->op = PTRACE_SYSCALL_INFO_EXIT; 980201766a2SElvira Khabirova info->exit.rval = syscall_get_error(child, regs); 981201766a2SElvira Khabirova info->exit.is_error = !!info->exit.rval; 982201766a2SElvira Khabirova if (!info->exit.is_error) 983201766a2SElvira Khabirova info->exit.rval = syscall_get_return_value(child, regs); 984201766a2SElvira Khabirova 985201766a2SElvira Khabirova /* is_error is the last field in struct ptrace_syscall_info.exit */ 986201766a2SElvira Khabirova return offsetofend(struct ptrace_syscall_info, exit.is_error); 987201766a2SElvira Khabirova } 988201766a2SElvira Khabirova 989201766a2SElvira Khabirova static int 990201766a2SElvira Khabirova ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size, 991201766a2SElvira Khabirova void __user *datavp) 992201766a2SElvira Khabirova { 993201766a2SElvira Khabirova struct pt_regs *regs = task_pt_regs(child); 994201766a2SElvira Khabirova struct ptrace_syscall_info info = { 995201766a2SElvira Khabirova .op = PTRACE_SYSCALL_INFO_NONE, 996201766a2SElvira Khabirova .arch = syscall_get_arch(child), 997201766a2SElvira Khabirova .instruction_pointer = instruction_pointer(regs), 998201766a2SElvira Khabirova .stack_pointer = user_stack_pointer(regs), 999201766a2SElvira Khabirova }; 1000201766a2SElvira Khabirova unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry); 1001201766a2SElvira Khabirova unsigned long write_size; 1002201766a2SElvira Khabirova 1003201766a2SElvira Khabirova /* 1004201766a2SElvira Khabirova * This does not need lock_task_sighand() to access 1005201766a2SElvira Khabirova * child->last_siginfo because ptrace_freeze_traced() 1006201766a2SElvira Khabirova * called earlier by ptrace_check_attach() ensures that 1007201766a2SElvira Khabirova * the tracee cannot go away and clear its last_siginfo. 1008201766a2SElvira Khabirova */ 1009201766a2SElvira Khabirova switch (child->last_siginfo ? child->last_siginfo->si_code : 0) { 1010201766a2SElvira Khabirova case SIGTRAP | 0x80: 1011201766a2SElvira Khabirova switch (child->ptrace_message) { 1012201766a2SElvira Khabirova case PTRACE_EVENTMSG_SYSCALL_ENTRY: 1013201766a2SElvira Khabirova actual_size = ptrace_get_syscall_info_entry(child, regs, 1014201766a2SElvira Khabirova &info); 1015201766a2SElvira Khabirova break; 1016201766a2SElvira Khabirova case PTRACE_EVENTMSG_SYSCALL_EXIT: 1017201766a2SElvira Khabirova actual_size = ptrace_get_syscall_info_exit(child, regs, 1018201766a2SElvira Khabirova &info); 1019201766a2SElvira Khabirova break; 1020201766a2SElvira Khabirova } 1021201766a2SElvira Khabirova break; 1022201766a2SElvira Khabirova case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8): 1023201766a2SElvira Khabirova actual_size = ptrace_get_syscall_info_seccomp(child, regs, 1024201766a2SElvira Khabirova &info); 1025201766a2SElvira Khabirova break; 1026201766a2SElvira Khabirova } 1027201766a2SElvira Khabirova 1028201766a2SElvira Khabirova write_size = min(actual_size, user_size); 1029201766a2SElvira Khabirova return copy_to_user(datavp, &info, write_size) ? -EFAULT : actual_size; 1030201766a2SElvira Khabirova } 1031201766a2SElvira Khabirova #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 10322225a122SSuresh Siddha 10331da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 10344abf9869SNamhyung Kim unsigned long addr, unsigned long data) 10351da177e4SLinus Torvalds { 1036fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 10371da177e4SLinus Torvalds int ret = -EIO; 1038ae7795bcSEric W. Biederman kernel_siginfo_t siginfo, *si; 10399fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 10409fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 1041fca26f26STejun Heo unsigned long flags; 10421da177e4SLinus Torvalds 10431da177e4SLinus Torvalds switch (request) { 104416c3e389SRoland McGrath case PTRACE_PEEKTEXT: 104516c3e389SRoland McGrath case PTRACE_PEEKDATA: 104616c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 104716c3e389SRoland McGrath case PTRACE_POKETEXT: 104816c3e389SRoland McGrath case PTRACE_POKEDATA: 104916c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 105016c3e389SRoland McGrath 10511da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 10521da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 10531da177e4SLinus Torvalds #endif 10541da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 10551da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 10561da177e4SLinus Torvalds break; 10571da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 10589fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 10591da177e4SLinus Torvalds break; 1060e16b2781SRoland McGrath 106184c751bdSAndrey Vagin case PTRACE_PEEKSIGINFO: 106284c751bdSAndrey Vagin ret = ptrace_peek_siginfo(child, addr, data); 106384c751bdSAndrey Vagin break; 106484c751bdSAndrey Vagin 10651da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 1066e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 1067e16b2781SRoland McGrath if (!ret) 10689fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 10691da177e4SLinus Torvalds break; 1070e16b2781SRoland McGrath 10711da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 10724cd2e0e7SEric W. Biederman ret = copy_siginfo_from_user(&siginfo, datavp); 10734cd2e0e7SEric W. Biederman if (!ret) 1074e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 10751da177e4SLinus Torvalds break; 1076e16b2781SRoland McGrath 1077fcfc2aa0SAndrei Vagin case PTRACE_GETSIGMASK: { 1078fcfc2aa0SAndrei Vagin sigset_t *mask; 1079fcfc2aa0SAndrei Vagin 108029000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 108129000caeSAndrey Vagin ret = -EINVAL; 108229000caeSAndrey Vagin break; 108329000caeSAndrey Vagin } 108429000caeSAndrey Vagin 1085fcfc2aa0SAndrei Vagin if (test_tsk_restore_sigmask(child)) 1086fcfc2aa0SAndrei Vagin mask = &child->saved_sigmask; 1087fcfc2aa0SAndrei Vagin else 1088fcfc2aa0SAndrei Vagin mask = &child->blocked; 1089fcfc2aa0SAndrei Vagin 1090fcfc2aa0SAndrei Vagin if (copy_to_user(datavp, mask, sizeof(sigset_t))) 109129000caeSAndrey Vagin ret = -EFAULT; 109229000caeSAndrey Vagin else 109329000caeSAndrey Vagin ret = 0; 109429000caeSAndrey Vagin 109529000caeSAndrey Vagin break; 1096fcfc2aa0SAndrei Vagin } 109729000caeSAndrey Vagin 109829000caeSAndrey Vagin case PTRACE_SETSIGMASK: { 109929000caeSAndrey Vagin sigset_t new_set; 110029000caeSAndrey Vagin 110129000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 110229000caeSAndrey Vagin ret = -EINVAL; 110329000caeSAndrey Vagin break; 110429000caeSAndrey Vagin } 110529000caeSAndrey Vagin 110629000caeSAndrey Vagin if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { 110729000caeSAndrey Vagin ret = -EFAULT; 110829000caeSAndrey Vagin break; 110929000caeSAndrey Vagin } 111029000caeSAndrey Vagin 111129000caeSAndrey Vagin sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); 111229000caeSAndrey Vagin 111329000caeSAndrey Vagin /* 111429000caeSAndrey Vagin * Every thread does recalc_sigpending() after resume, so 111529000caeSAndrey Vagin * retarget_shared_pending() and recalc_sigpending() are not 111629000caeSAndrey Vagin * called here. 111729000caeSAndrey Vagin */ 111829000caeSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 111929000caeSAndrey Vagin child->blocked = new_set; 112029000caeSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 112129000caeSAndrey Vagin 1122fcfc2aa0SAndrei Vagin clear_tsk_restore_sigmask(child); 1123fcfc2aa0SAndrei Vagin 112429000caeSAndrey Vagin ret = 0; 112529000caeSAndrey Vagin break; 112629000caeSAndrey Vagin } 112729000caeSAndrey Vagin 1128fca26f26STejun Heo case PTRACE_INTERRUPT: 1129fca26f26STejun Heo /* 1130fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 1131fca26f26STejun Heo * control. At least one trap is guaranteed to happen 1132fca26f26STejun Heo * after this request. If @child is already trapped, the 1133fca26f26STejun Heo * current trap is not disturbed and another trap will 1134fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 1135fca26f26STejun Heo * 1136fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 1137fca26f26STejun Heo * the pending condition is cleared regardless. 1138fca26f26STejun Heo */ 1139fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 1140fca26f26STejun Heo break; 1141fca26f26STejun Heo 1142544b2c91STejun Heo /* 1143544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 1144544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 1145544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 1146544b2c91STejun Heo * tracee into STOP. 1147544b2c91STejun Heo */ 1148fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 1149910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 1150544b2c91STejun Heo 1151544b2c91STejun Heo unlock_task_sighand(child, &flags); 1152544b2c91STejun Heo ret = 0; 1153544b2c91STejun Heo break; 1154544b2c91STejun Heo 1155544b2c91STejun Heo case PTRACE_LISTEN: 1156544b2c91STejun Heo /* 1157544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 1158544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 1159544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 1160544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 1161544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 1162544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 1163544b2c91STejun Heo */ 1164544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 1165544b2c91STejun Heo break; 1166544b2c91STejun Heo 1167544b2c91STejun Heo si = child->last_siginfo; 1168f9d81f61SOleg Nesterov if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { 1169544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 1170544b2c91STejun Heo /* 1171f9d81f61SOleg Nesterov * If NOTIFY is set, it means event happened between 1172f9d81f61SOleg Nesterov * start of this trap and now. Trigger re-trap. 1173544b2c91STejun Heo */ 1174544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 1175910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 1176fca26f26STejun Heo ret = 0; 1177f9d81f61SOleg Nesterov } 1178f9d81f61SOleg Nesterov unlock_task_sighand(child, &flags); 1179fca26f26STejun Heo break; 1180fca26f26STejun Heo 11811bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 11821bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 11831bcf5482SAlexey Dobriyan break; 118436df29d7SRoland McGrath 11859c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 11869c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 1187e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 11889c1a1259SMike Frysinger unsigned long tmp = 0; 11899c1a1259SMike Frysinger 1190e0129ef9SOleg Nesterov ret = -ESRCH; 1191e0129ef9SOleg Nesterov if (!mm) 1192e0129ef9SOleg Nesterov break; 1193e0129ef9SOleg Nesterov 11949c1a1259SMike Frysinger switch (addr) { 11959c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 1196e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 11979c1a1259SMike Frysinger break; 11989c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 1199e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 12009c1a1259SMike Frysinger break; 12019c1a1259SMike Frysinger default: 12029c1a1259SMike Frysinger break; 12039c1a1259SMike Frysinger } 1204e0129ef9SOleg Nesterov mmput(mm); 12059c1a1259SMike Frysinger 12069fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 12079c1a1259SMike Frysinger break; 12089c1a1259SMike Frysinger } 12099c1a1259SMike Frysinger #endif 12109c1a1259SMike Frysinger 121136df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 121236df29d7SRoland McGrath case PTRACE_SINGLESTEP: 121336df29d7SRoland McGrath #endif 12145b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 12155b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 12165b88abbfSRoland McGrath #endif 121736df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 121836df29d7SRoland McGrath case PTRACE_SYSEMU: 121936df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 122036df29d7SRoland McGrath #endif 122136df29d7SRoland McGrath case PTRACE_SYSCALL: 122236df29d7SRoland McGrath case PTRACE_CONT: 122336df29d7SRoland McGrath return ptrace_resume(child, request, data); 122436df29d7SRoland McGrath 122536df29d7SRoland McGrath case PTRACE_KILL: 12266a2d90baSEric W. Biederman send_sig_info(SIGKILL, SEND_SIG_NOINFO, child); 122736df29d7SRoland McGrath return 0; 122836df29d7SRoland McGrath 12292225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 12302225a122SSuresh Siddha case PTRACE_GETREGSET: 123129000caeSAndrey Vagin case PTRACE_SETREGSET: { 12322225a122SSuresh Siddha struct iovec kiov; 12339fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 12342225a122SSuresh Siddha 123596d4f267SLinus Torvalds if (!access_ok(uiov, sizeof(*uiov))) 12362225a122SSuresh Siddha return -EFAULT; 12372225a122SSuresh Siddha 12382225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 12392225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 12402225a122SSuresh Siddha return -EFAULT; 12412225a122SSuresh Siddha 12422225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 12432225a122SSuresh Siddha if (!ret) 12442225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 12452225a122SSuresh Siddha break; 12462225a122SSuresh Siddha } 1247201766a2SElvira Khabirova 1248201766a2SElvira Khabirova case PTRACE_GET_SYSCALL_INFO: 1249201766a2SElvira Khabirova ret = ptrace_get_syscall_info(child, addr, datavp); 1250201766a2SElvira Khabirova break; 12512225a122SSuresh Siddha #endif 1252f8e529edSTycho Andersen 1253f8e529edSTycho Andersen case PTRACE_SECCOMP_GET_FILTER: 1254f8e529edSTycho Andersen ret = seccomp_get_filter(child, addr, datavp); 1255f8e529edSTycho Andersen break; 1256f8e529edSTycho Andersen 125726500475STycho Andersen case PTRACE_SECCOMP_GET_METADATA: 125826500475STycho Andersen ret = seccomp_get_metadata(child, addr, datavp); 125926500475STycho Andersen break; 126026500475STycho Andersen 126190f093faSPiotr Figiel #ifdef CONFIG_RSEQ 126290f093faSPiotr Figiel case PTRACE_GET_RSEQ_CONFIGURATION: 126390f093faSPiotr Figiel ret = ptrace_get_rseq_configuration(child, addr, datavp); 126490f093faSPiotr Figiel break; 126590f093faSPiotr Figiel #endif 126690f093faSPiotr Figiel 12671da177e4SLinus Torvalds default: 12681da177e4SLinus Torvalds break; 12691da177e4SLinus Torvalds } 12701da177e4SLinus Torvalds 12711da177e4SLinus Torvalds return ret; 12721da177e4SLinus Torvalds } 1273481bed45SChristoph Hellwig 12744abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 12754abf9869SNamhyung Kim unsigned long, data) 1276481bed45SChristoph Hellwig { 1277481bed45SChristoph Hellwig struct task_struct *child; 1278481bed45SChristoph Hellwig long ret; 1279481bed45SChristoph Hellwig 12806b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 12816b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 1282481bed45SChristoph Hellwig goto out; 12836b9c7ed8SChristoph Hellwig } 12846b9c7ed8SChristoph Hellwig 12852ee08260SMike Rapoport child = find_get_task_by_vpid(pid); 12862ee08260SMike Rapoport if (!child) { 12872ee08260SMike Rapoport ret = -ESRCH; 12886b9c7ed8SChristoph Hellwig goto out; 12896b9c7ed8SChristoph Hellwig } 1290481bed45SChristoph Hellwig 12913544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1292aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 1293005f18dfSChristoph Hellwig goto out_put_task_struct; 1294481bed45SChristoph Hellwig } 1295481bed45SChristoph Hellwig 1296fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1297fca26f26STejun Heo request == PTRACE_INTERRUPT); 1298481bed45SChristoph Hellwig if (ret < 0) 1299481bed45SChristoph Hellwig goto out_put_task_struct; 1300481bed45SChristoph Hellwig 1301481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 13029899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 13039899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 1304481bed45SChristoph Hellwig 1305481bed45SChristoph Hellwig out_put_task_struct: 1306481bed45SChristoph Hellwig put_task_struct(child); 1307481bed45SChristoph Hellwig out: 1308481bed45SChristoph Hellwig return ret; 1309481bed45SChristoph Hellwig } 131076647323SAlexey Dobriyan 13114abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 13124abf9869SNamhyung Kim unsigned long data) 131376647323SAlexey Dobriyan { 131476647323SAlexey Dobriyan unsigned long tmp; 131576647323SAlexey Dobriyan int copied; 131676647323SAlexey Dobriyan 131784d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); 131876647323SAlexey Dobriyan if (copied != sizeof(tmp)) 131976647323SAlexey Dobriyan return -EIO; 132076647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 132176647323SAlexey Dobriyan } 1322f284ce72SAlexey Dobriyan 13234abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 13244abf9869SNamhyung Kim unsigned long data) 1325f284ce72SAlexey Dobriyan { 1326f284ce72SAlexey Dobriyan int copied; 1327f284ce72SAlexey Dobriyan 132884d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &data, sizeof(data), 1329f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1330f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 1331f284ce72SAlexey Dobriyan } 1332032d82d9SRoland McGrath 133396b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 1334032d82d9SRoland McGrath 1335032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 1336032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 1337032d82d9SRoland McGrath { 1338032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 1339032d82d9SRoland McGrath compat_ulong_t word; 1340ae7795bcSEric W. Biederman kernel_siginfo_t siginfo; 1341032d82d9SRoland McGrath int ret; 1342032d82d9SRoland McGrath 1343032d82d9SRoland McGrath switch (request) { 1344032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 1345032d82d9SRoland McGrath case PTRACE_PEEKDATA: 134684d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &word, sizeof(word), 1347f307ab6dSLorenzo Stoakes FOLL_FORCE); 1348032d82d9SRoland McGrath if (ret != sizeof(word)) 1349032d82d9SRoland McGrath ret = -EIO; 1350032d82d9SRoland McGrath else 1351032d82d9SRoland McGrath ret = put_user(word, datap); 1352032d82d9SRoland McGrath break; 1353032d82d9SRoland McGrath 1354032d82d9SRoland McGrath case PTRACE_POKETEXT: 1355032d82d9SRoland McGrath case PTRACE_POKEDATA: 135684d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &data, sizeof(data), 1357f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1358032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 1359032d82d9SRoland McGrath break; 1360032d82d9SRoland McGrath 1361032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 1362032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 1363032d82d9SRoland McGrath break; 1364032d82d9SRoland McGrath 1365e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 1366e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 1367e16b2781SRoland McGrath if (!ret) 1368e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 1369e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 1370e16b2781SRoland McGrath &siginfo); 1371e16b2781SRoland McGrath break; 1372e16b2781SRoland McGrath 1373e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 13744cd2e0e7SEric W. Biederman ret = copy_siginfo_from_user32( 13754cd2e0e7SEric W. Biederman &siginfo, (struct compat_siginfo __user *) datap); 13764cd2e0e7SEric W. Biederman if (!ret) 1377e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 1378e16b2781SRoland McGrath break; 13792225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 13802225a122SSuresh Siddha case PTRACE_GETREGSET: 13812225a122SSuresh Siddha case PTRACE_SETREGSET: 13822225a122SSuresh Siddha { 13832225a122SSuresh Siddha struct iovec kiov; 13842225a122SSuresh Siddha struct compat_iovec __user *uiov = 13852225a122SSuresh Siddha (struct compat_iovec __user *) datap; 13862225a122SSuresh Siddha compat_uptr_t ptr; 13872225a122SSuresh Siddha compat_size_t len; 13882225a122SSuresh Siddha 138996d4f267SLinus Torvalds if (!access_ok(uiov, sizeof(*uiov))) 13902225a122SSuresh Siddha return -EFAULT; 13912225a122SSuresh Siddha 13922225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 13932225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 13942225a122SSuresh Siddha return -EFAULT; 13952225a122SSuresh Siddha 13962225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 13972225a122SSuresh Siddha kiov.iov_len = len; 13982225a122SSuresh Siddha 13992225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 14002225a122SSuresh Siddha if (!ret) 14012225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 14022225a122SSuresh Siddha break; 14032225a122SSuresh Siddha } 14042225a122SSuresh Siddha #endif 1405e16b2781SRoland McGrath 1406032d82d9SRoland McGrath default: 1407032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 1408032d82d9SRoland McGrath } 1409032d82d9SRoland McGrath 1410032d82d9SRoland McGrath return ret; 1411032d82d9SRoland McGrath } 1412c269f196SRoland McGrath 141362a6fa97SHeiko Carstens COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, 141462a6fa97SHeiko Carstens compat_long_t, addr, compat_long_t, data) 1415c269f196SRoland McGrath { 1416c269f196SRoland McGrath struct task_struct *child; 1417c269f196SRoland McGrath long ret; 1418c269f196SRoland McGrath 1419c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1420c269f196SRoland McGrath ret = ptrace_traceme(); 1421c269f196SRoland McGrath goto out; 1422c269f196SRoland McGrath } 1423c269f196SRoland McGrath 14242ee08260SMike Rapoport child = find_get_task_by_vpid(pid); 14252ee08260SMike Rapoport if (!child) { 14262ee08260SMike Rapoport ret = -ESRCH; 1427c269f196SRoland McGrath goto out; 1428c269f196SRoland McGrath } 1429c269f196SRoland McGrath 14303544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1431aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 1432c269f196SRoland McGrath goto out_put_task_struct; 1433c269f196SRoland McGrath } 1434c269f196SRoland McGrath 1435fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1436fca26f26STejun Heo request == PTRACE_INTERRUPT); 14379899d11fSOleg Nesterov if (!ret) { 1438c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 14399899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 14409899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 14419899d11fSOleg Nesterov } 1442c269f196SRoland McGrath 1443c269f196SRoland McGrath out_put_task_struct: 1444c269f196SRoland McGrath put_task_struct(child); 1445c269f196SRoland McGrath out: 1446c269f196SRoland McGrath return ret; 1447c269f196SRoland McGrath } 144896b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1449