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> 35*3f67987cSGregory Price #include <linux/syscall_user_dispatch.h> 361da177e4SLinus Torvalds 37201766a2SElvira Khabirova #include <asm/syscall.h> /* for syscall_get_* */ 38201766a2SElvira Khabirova 3984d77d3fSEric W. Biederman /* 4084d77d3fSEric W. Biederman * Access another process' address space via ptrace. 4184d77d3fSEric W. Biederman * Source/target buffer must be kernel space, 4284d77d3fSEric W. Biederman * Do not walk the page table directly, use get_user_pages 4384d77d3fSEric W. Biederman */ 4484d77d3fSEric W. Biederman int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, 4584d77d3fSEric W. Biederman void *buf, int len, unsigned int gup_flags) 4684d77d3fSEric W. Biederman { 4784d77d3fSEric W. Biederman struct mm_struct *mm; 4884d77d3fSEric W. Biederman int ret; 4984d77d3fSEric W. Biederman 5084d77d3fSEric W. Biederman mm = get_task_mm(tsk); 5184d77d3fSEric W. Biederman if (!mm) 5284d77d3fSEric W. Biederman return 0; 5384d77d3fSEric W. Biederman 5484d77d3fSEric W. Biederman if (!tsk->ptrace || 5584d77d3fSEric W. Biederman (current != tsk->parent) || 5684d77d3fSEric W. Biederman ((get_dumpable(mm) != SUID_DUMP_USER) && 5784d77d3fSEric W. Biederman !ptracer_capable(tsk, mm->user_ns))) { 5884d77d3fSEric W. Biederman mmput(mm); 5984d77d3fSEric W. Biederman return 0; 6084d77d3fSEric W. Biederman } 6184d77d3fSEric W. Biederman 62d3f5ffcaSJohn Hubbard ret = __access_remote_vm(mm, addr, buf, len, gup_flags); 6384d77d3fSEric W. Biederman mmput(mm); 6484d77d3fSEric W. Biederman 6584d77d3fSEric W. Biederman return ret; 6684d77d3fSEric W. Biederman } 6784d77d3fSEric W. Biederman 68bf53de90SMarkus Metzger 69c70d9d80SEric W. Biederman void __ptrace_link(struct task_struct *child, struct task_struct *new_parent, 70c70d9d80SEric W. Biederman const struct cred *ptracer_cred) 71c70d9d80SEric W. Biederman { 72c70d9d80SEric W. Biederman BUG_ON(!list_empty(&child->ptrace_entry)); 73c70d9d80SEric W. Biederman list_add(&child->ptrace_entry, &new_parent->ptraced); 74c70d9d80SEric W. Biederman child->parent = new_parent; 75c70d9d80SEric W. Biederman child->ptracer_cred = get_cred(ptracer_cred); 76c70d9d80SEric W. Biederman } 77c70d9d80SEric W. Biederman 78bf53de90SMarkus Metzger /* 791da177e4SLinus Torvalds * ptrace a task: make the debugger its new parent and 801da177e4SLinus Torvalds * move it to the ptrace list. 811da177e4SLinus Torvalds * 821da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 831da177e4SLinus Torvalds */ 84c70d9d80SEric W. Biederman static void ptrace_link(struct task_struct *child, struct task_struct *new_parent) 851da177e4SLinus Torvalds { 866994eefbSJann Horn __ptrace_link(child, new_parent, current_cred()); 871da177e4SLinus Torvalds } 881da177e4SLinus Torvalds 89e3bd058fSTejun Heo /** 90e3bd058fSTejun Heo * __ptrace_unlink - unlink ptracee and restore its execution state 91e3bd058fSTejun Heo * @child: ptracee to be unlinked 921da177e4SLinus Torvalds * 930e9f0a4aSTejun Heo * Remove @child from the ptrace list, move it back to the original parent, 940e9f0a4aSTejun Heo * and restore the execution state so that it conforms to the group stop 950e9f0a4aSTejun Heo * state. 960e9f0a4aSTejun Heo * 970e9f0a4aSTejun Heo * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer 980e9f0a4aSTejun Heo * exiting. For PTRACE_DETACH, unless the ptracee has been killed between 990e9f0a4aSTejun Heo * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. 1000e9f0a4aSTejun Heo * If the ptracer is exiting, the ptracee can be in any state. 1010e9f0a4aSTejun Heo * 1020e9f0a4aSTejun Heo * After detach, the ptracee should be in a state which conforms to the 1030e9f0a4aSTejun Heo * group stop. If the group is stopped or in the process of stopping, the 1040e9f0a4aSTejun Heo * ptracee should be put into TASK_STOPPED; otherwise, it should be woken 1050e9f0a4aSTejun Heo * up from TASK_TRACED. 1060e9f0a4aSTejun Heo * 1070e9f0a4aSTejun Heo * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, 1080e9f0a4aSTejun Heo * it goes through TRACED -> RUNNING -> STOPPED transition which is similar 1090e9f0a4aSTejun Heo * to but in the opposite direction of what happens while attaching to a 1100e9f0a4aSTejun Heo * stopped task. However, in this direction, the intermediate RUNNING 1110e9f0a4aSTejun Heo * state is not hidden even from the current ptracer and if it immediately 1120e9f0a4aSTejun Heo * re-attaches and performs a WNOHANG wait(2), it may fail. 113e3bd058fSTejun Heo * 114e3bd058fSTejun Heo * CONTEXT: 115e3bd058fSTejun Heo * write_lock_irq(tasklist_lock) 1161da177e4SLinus Torvalds */ 11736c8b586SIngo Molnar void __ptrace_unlink(struct task_struct *child) 1181da177e4SLinus Torvalds { 11964b875f7SEric W. Biederman const struct cred *old_cred; 1205ecfbae0SOleg Nesterov BUG_ON(!child->ptrace); 1215ecfbae0SOleg Nesterov 12264c19ba2SGabriel Krisman Bertazi clear_task_syscall_work(child, SYSCALL_TRACE); 12364eb35f7SGabriel Krisman Bertazi #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) 12464eb35f7SGabriel Krisman Bertazi clear_task_syscall_work(child, SYSCALL_EMU); 12515532fd6SSudeep Holla #endif 1260a5bf409SAles Novak 1271da177e4SLinus Torvalds child->parent = child->real_parent; 128f470021aSRoland McGrath list_del_init(&child->ptrace_entry); 12964b875f7SEric W. Biederman old_cred = child->ptracer_cred; 13064b875f7SEric W. Biederman child->ptracer_cred = NULL; 13164b875f7SEric W. Biederman put_cred(old_cred); 1321da177e4SLinus Torvalds 1331da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 1341333ab03SOleg Nesterov child->ptrace = 0; 1351da177e4SLinus Torvalds /* 13673ddff2bSTejun Heo * Clear all pending traps and TRAPPING. TRAPPING should be 13773ddff2bSTejun Heo * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. 13873ddff2bSTejun Heo */ 13973ddff2bSTejun Heo task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); 14073ddff2bSTejun Heo task_clear_jobctl_trapping(child); 14173ddff2bSTejun Heo 14273ddff2bSTejun Heo /* 143a8f072c1STejun Heo * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and 1440e9f0a4aSTejun Heo * @child isn't dead. 1451da177e4SLinus Torvalds */ 1460e9f0a4aSTejun Heo if (!(child->flags & PF_EXITING) && 1470e9f0a4aSTejun Heo (child->signal->flags & SIGNAL_STOP_STOPPED || 1488a88951bSOleg Nesterov child->signal->group_stop_count)) { 149a8f072c1STejun Heo child->jobctl |= JOBCTL_STOP_PENDING; 1500e9f0a4aSTejun Heo 1510e9f0a4aSTejun Heo /* 1528a88951bSOleg Nesterov * This is only possible if this thread was cloned by the 1538a88951bSOleg Nesterov * traced task running in the stopped group, set the signal 1548a88951bSOleg Nesterov * for the future reports. 1558a88951bSOleg Nesterov * FIXME: we should change ptrace_init_task() to handle this 1568a88951bSOleg Nesterov * case. 1578a88951bSOleg Nesterov */ 1588a88951bSOleg Nesterov if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) 1598a88951bSOleg Nesterov child->jobctl |= SIGSTOP; 1608a88951bSOleg Nesterov } 1618a88951bSOleg Nesterov 1628a88951bSOleg Nesterov /* 1630e9f0a4aSTejun Heo * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick 1640e9f0a4aSTejun Heo * @child in the butt. Note that @resume should be used iff @child 1650e9f0a4aSTejun Heo * is in TASK_TRACED; otherwise, we might unduly disrupt 1660e9f0a4aSTejun Heo * TASK_KILLABLE sleeps. 1670e9f0a4aSTejun Heo */ 168a8f072c1STejun Heo if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) 169910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 1700e9f0a4aSTejun Heo 1711da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 1721da177e4SLinus Torvalds } 1731da177e4SLinus Torvalds 174dbb5afadSOleg Nesterov static bool looks_like_a_spurious_pid(struct task_struct *task) 175dbb5afadSOleg Nesterov { 176dbb5afadSOleg Nesterov if (task->exit_code != ((PTRACE_EVENT_EXEC << 8) | SIGTRAP)) 177dbb5afadSOleg Nesterov return false; 178dbb5afadSOleg Nesterov 179dbb5afadSOleg Nesterov if (task_pid_vnr(task) == task->ptrace_message) 180dbb5afadSOleg Nesterov return false; 181dbb5afadSOleg Nesterov /* 182dbb5afadSOleg Nesterov * The tracee changed its pid but the PTRACE_EVENT_EXEC event 183dbb5afadSOleg Nesterov * was not wait()'ed, most probably debugger targets the old 184dbb5afadSOleg Nesterov * leader which was destroyed in de_thread(). 185dbb5afadSOleg Nesterov */ 186dbb5afadSOleg Nesterov return true; 187dbb5afadSOleg Nesterov } 188dbb5afadSOleg Nesterov 18931cae1eaSPeter Zijlstra /* 19031cae1eaSPeter Zijlstra * Ensure that nothing can wake it up, even SIGKILL 19131cae1eaSPeter Zijlstra * 19231cae1eaSPeter Zijlstra * A task is switched to this state while a ptrace operation is in progress; 19331cae1eaSPeter Zijlstra * such that the ptrace operation is uninterruptible. 19431cae1eaSPeter Zijlstra */ 1959899d11fSOleg Nesterov static bool ptrace_freeze_traced(struct task_struct *task) 1969899d11fSOleg Nesterov { 1979899d11fSOleg Nesterov bool ret = false; 1989899d11fSOleg Nesterov 1999899d11fSOleg Nesterov /* Lockless, nobody but us can set this flag */ 2009899d11fSOleg Nesterov if (task->jobctl & JOBCTL_LISTENING) 2019899d11fSOleg Nesterov return ret; 2029899d11fSOleg Nesterov 2039899d11fSOleg Nesterov spin_lock_irq(&task->sighand->siglock); 204dbb5afadSOleg Nesterov if (task_is_traced(task) && !looks_like_a_spurious_pid(task) && 205dbb5afadSOleg Nesterov !__fatal_signal_pending(task)) { 2062500ad1cSEric W. Biederman task->jobctl |= JOBCTL_PTRACE_FROZEN; 2079899d11fSOleg Nesterov ret = true; 2089899d11fSOleg Nesterov } 2099899d11fSOleg Nesterov spin_unlock_irq(&task->sighand->siglock); 2109899d11fSOleg Nesterov 2119899d11fSOleg Nesterov return ret; 2129899d11fSOleg Nesterov } 2139899d11fSOleg Nesterov 2149899d11fSOleg Nesterov static void ptrace_unfreeze_traced(struct task_struct *task) 2159899d11fSOleg Nesterov { 2162500ad1cSEric W. Biederman unsigned long flags; 2179899d11fSOleg Nesterov 2185402e97aSbsegall@google.com /* 2192500ad1cSEric W. Biederman * The child may be awake and may have cleared 2202500ad1cSEric W. Biederman * JOBCTL_PTRACE_FROZEN (see ptrace_resume). The child will 2212500ad1cSEric W. Biederman * not set JOBCTL_PTRACE_FROZEN or enter __TASK_TRACED anew. 2225402e97aSbsegall@google.com */ 2232500ad1cSEric W. Biederman if (lock_task_sighand(task, &flags)) { 2242500ad1cSEric W. Biederman task->jobctl &= ~JOBCTL_PTRACE_FROZEN; 22531cae1eaSPeter Zijlstra if (__fatal_signal_pending(task)) { 226de2a3477SSven Schnelle task->jobctl &= ~JOBCTL_TRACED; 2279899d11fSOleg Nesterov wake_up_state(task, __TASK_TRACED); 2285402e97aSbsegall@google.com } 2292500ad1cSEric W. Biederman unlock_task_sighand(task, &flags); 230755e276bSTejun Heo } 2311da177e4SLinus Torvalds } 2321da177e4SLinus Torvalds 233755e276bSTejun Heo /** 234755e276bSTejun Heo * ptrace_check_attach - check whether ptracee is ready for ptrace operation 235755e276bSTejun Heo * @child: ptracee to check for 236755e276bSTejun Heo * @ignore_state: don't check whether @child is currently %TASK_TRACED 237755e276bSTejun Heo * 238755e276bSTejun Heo * Check whether @child is being ptraced by %current and ready for further 239755e276bSTejun Heo * ptrace operations. If @ignore_state is %false, @child also should be in 240755e276bSTejun Heo * %TASK_TRACED state and on return the child is guaranteed to be traced 241755e276bSTejun Heo * and not executing. If @ignore_state is %true, @child can be in any 242755e276bSTejun Heo * state. 243755e276bSTejun Heo * 244755e276bSTejun Heo * CONTEXT: 245755e276bSTejun Heo * Grabs and releases tasklist_lock and @child->sighand->siglock. 246755e276bSTejun Heo * 247755e276bSTejun Heo * RETURNS: 248755e276bSTejun Heo * 0 on success, -ESRCH if %child is not ready. 2491da177e4SLinus Torvalds */ 250edea0d03SOleg Nesterov static int ptrace_check_attach(struct task_struct *child, bool ignore_state) 2511da177e4SLinus Torvalds { 2521da177e4SLinus Torvalds int ret = -ESRCH; 2531da177e4SLinus Torvalds 2541da177e4SLinus Torvalds /* 2551da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 2561da177e4SLinus Torvalds * possible race where someone else was tracing our child and 2571da177e4SLinus Torvalds * detached between these two checks. After this locked check, 2581da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 2591da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 2601da177e4SLinus Torvalds */ 2611da177e4SLinus Torvalds read_lock(&tasklist_lock); 2629899d11fSOleg Nesterov if (child->ptrace && child->parent == current) { 263c0c0b649SOleg Nesterov /* 264c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 265c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 266c0c0b649SOleg Nesterov */ 2679899d11fSOleg Nesterov if (ignore_state || ptrace_freeze_traced(child)) 268321fb561SOleg Nesterov ret = 0; 2691da177e4SLinus Torvalds } 2701da177e4SLinus Torvalds read_unlock(&tasklist_lock); 2711da177e4SLinus Torvalds 2727b0fe136SEric W. Biederman if (!ret && !ignore_state && 273f5d39b02SPeter Zijlstra WARN_ON_ONCE(!wait_task_inactive(child, __TASK_TRACED|TASK_FROZEN))) 2749899d11fSOleg Nesterov ret = -ESRCH; 2751da177e4SLinus Torvalds 2761da177e4SLinus Torvalds return ret; 2771da177e4SLinus Torvalds } 2781da177e4SLinus Torvalds 279cf237052SMickaël Salaün static bool ptrace_has_cap(struct user_namespace *ns, unsigned int mode) 28069f594a3SEric Paris { 28169f594a3SEric Paris if (mode & PTRACE_MODE_NOAUDIT) 282cf237052SMickaël Salaün return ns_capable_noaudit(ns, CAP_SYS_PTRACE); 283cf237052SMickaël Salaün return ns_capable(ns, CAP_SYS_PTRACE); 28469f594a3SEric Paris } 28569f594a3SEric Paris 2869f99798fSTetsuo Handa /* Returns 0 on success, -errno on denial. */ 2879f99798fSTetsuo Handa static int __ptrace_may_access(struct task_struct *task, unsigned int mode) 288ab8d11beSMiklos Szeredi { 289c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 290bfedb589SEric W. Biederman struct mm_struct *mm; 291caaee623SJann Horn kuid_t caller_uid; 292caaee623SJann Horn kgid_t caller_gid; 293caaee623SJann Horn 294caaee623SJann Horn if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { 295caaee623SJann Horn WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); 296caaee623SJann Horn return -EPERM; 297caaee623SJann Horn } 298b6dff3ecSDavid Howells 299df26c40eSEric W. Biederman /* May we inspect the given task? 300df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 301df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 302df26c40eSEric W. Biederman * 303df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 304df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 305df26c40eSEric W. Biederman * or halting the specified task is impossible. 306df26c40eSEric W. Biederman */ 307caaee623SJann Horn 308df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 30973af963fSMark Grondona if (same_thread_group(task, current)) 310df26c40eSEric W. Biederman return 0; 311c69e8d9cSDavid Howells rcu_read_lock(); 312caaee623SJann Horn if (mode & PTRACE_MODE_FSCREDS) { 313caaee623SJann Horn caller_uid = cred->fsuid; 314caaee623SJann Horn caller_gid = cred->fsgid; 315caaee623SJann Horn } else { 316caaee623SJann Horn /* 317caaee623SJann Horn * Using the euid would make more sense here, but something 318caaee623SJann Horn * in userland might rely on the old behavior, and this 319caaee623SJann Horn * shouldn't be a security problem since 320caaee623SJann Horn * PTRACE_MODE_REALCREDS implies that the caller explicitly 321caaee623SJann Horn * used a syscall that requests access to another process 322caaee623SJann Horn * (and not a filesystem syscall to procfs). 323caaee623SJann Horn */ 324caaee623SJann Horn caller_uid = cred->uid; 325caaee623SJann Horn caller_gid = cred->gid; 326caaee623SJann Horn } 327c69e8d9cSDavid Howells tcred = __task_cred(task); 328caaee623SJann Horn if (uid_eq(caller_uid, tcred->euid) && 329caaee623SJann Horn uid_eq(caller_uid, tcred->suid) && 330caaee623SJann Horn uid_eq(caller_uid, tcred->uid) && 331caaee623SJann Horn gid_eq(caller_gid, tcred->egid) && 332caaee623SJann Horn gid_eq(caller_gid, tcred->sgid) && 333caaee623SJann Horn gid_eq(caller_gid, tcred->gid)) 3348409cca7SSerge E. Hallyn goto ok; 335cf237052SMickaël Salaün if (ptrace_has_cap(tcred->user_ns, mode)) 3368409cca7SSerge E. Hallyn goto ok; 337c69e8d9cSDavid Howells rcu_read_unlock(); 338ab8d11beSMiklos Szeredi return -EPERM; 3398409cca7SSerge E. Hallyn ok: 340c69e8d9cSDavid Howells rcu_read_unlock(); 341f6581f5bSJann Horn /* 342f6581f5bSJann Horn * If a task drops privileges and becomes nondumpable (through a syscall 343f6581f5bSJann Horn * like setresuid()) while we are trying to access it, we must ensure 344f6581f5bSJann Horn * that the dumpability is read after the credentials; otherwise, 345f6581f5bSJann Horn * we may be able to attach to a task that we shouldn't be able to 346f6581f5bSJann Horn * attach to (as if the task had dropped privileges without becoming 347f6581f5bSJann Horn * nondumpable). 348f6581f5bSJann Horn * Pairs with a write barrier in commit_creds(). 349f6581f5bSJann Horn */ 350f6581f5bSJann Horn smp_rmb(); 351bfedb589SEric W. Biederman mm = task->mm; 352bfedb589SEric W. Biederman if (mm && 353bfedb589SEric W. Biederman ((get_dumpable(mm) != SUID_DUMP_USER) && 354cf237052SMickaël Salaün !ptrace_has_cap(mm->user_ns, mode))) 355ab8d11beSMiklos Szeredi return -EPERM; 356ab8d11beSMiklos Szeredi 3579e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 358ab8d11beSMiklos Szeredi } 359ab8d11beSMiklos Szeredi 360006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 361ab8d11beSMiklos Szeredi { 362ab8d11beSMiklos Szeredi int err; 363ab8d11beSMiklos Szeredi task_lock(task); 364006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 365ab8d11beSMiklos Szeredi task_unlock(task); 3663a709703SRoland McGrath return !err; 367ab8d11beSMiklos Szeredi } 368ab8d11beSMiklos Szeredi 369ee1fee90SJann Horn static int check_ptrace_options(unsigned long data) 370ee1fee90SJann Horn { 371ee1fee90SJann Horn if (data & ~(unsigned long)PTRACE_O_MASK) 372ee1fee90SJann Horn return -EINVAL; 373ee1fee90SJann Horn 374ee1fee90SJann Horn if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { 375ee1fee90SJann Horn if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || 376ee1fee90SJann Horn !IS_ENABLED(CONFIG_SECCOMP)) 377ee1fee90SJann Horn return -EINVAL; 378ee1fee90SJann Horn 379ee1fee90SJann Horn if (!capable(CAP_SYS_ADMIN)) 380ee1fee90SJann Horn return -EPERM; 381ee1fee90SJann Horn 382ee1fee90SJann Horn if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || 383ee1fee90SJann Horn current->ptrace & PT_SUSPEND_SECCOMP) 384ee1fee90SJann Horn return -EPERM; 385ee1fee90SJann Horn } 386ee1fee90SJann Horn return 0; 387ee1fee90SJann Horn } 388ee1fee90SJann Horn 3893544d72aSTejun Heo static int ptrace_attach(struct task_struct *task, long request, 390aa9147c9SDenys Vlasenko unsigned long addr, 3913544d72aSTejun Heo unsigned long flags) 3921da177e4SLinus Torvalds { 3933544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 3941da177e4SLinus Torvalds int retval; 395f5b40e36SLinus Torvalds 3963544d72aSTejun Heo retval = -EIO; 397aa9147c9SDenys Vlasenko if (seize) { 398aa9147c9SDenys Vlasenko if (addr != 0) 3993544d72aSTejun Heo goto out; 400ee1fee90SJann Horn /* 401ee1fee90SJann Horn * This duplicates the check in check_ptrace_options() because 402ee1fee90SJann Horn * ptrace_attach() and ptrace_setoptions() have historically 403ee1fee90SJann Horn * used different error codes for unknown ptrace options. 404ee1fee90SJann Horn */ 405aa9147c9SDenys Vlasenko if (flags & ~(unsigned long)PTRACE_O_MASK) 406aa9147c9SDenys Vlasenko goto out; 407ee1fee90SJann Horn retval = check_ptrace_options(flags); 408ee1fee90SJann Horn if (retval) 409ee1fee90SJann Horn return retval; 410aa9147c9SDenys Vlasenko flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); 411aa9147c9SDenys Vlasenko } else { 412aa9147c9SDenys Vlasenko flags = PT_PTRACED; 413aa9147c9SDenys Vlasenko } 4143544d72aSTejun Heo 415a5cb013dSAl Viro audit_ptrace(task); 416a5cb013dSAl Viro 4171da177e4SLinus Torvalds retval = -EPERM; 418e8b33b8cSJens Axboe if (unlikely(task->flags & PF_KTHREAD)) 419b79b7ba9SOleg Nesterov goto out; 420bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 421f5b40e36SLinus Torvalds goto out; 422f5b40e36SLinus Torvalds 423f2f0b00aSOleg Nesterov /* 424f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 42586b6c1f3SDenys Vlasenko * SUID, SGID and LSM creds get determined differently 4265e751e99SDavid Howells * under ptrace. 427d84f4f99SDavid Howells */ 428793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 4299b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 430d84f4f99SDavid Howells goto out; 4314b105cbbSOleg Nesterov 432f5b40e36SLinus Torvalds task_lock(task); 433caaee623SJann Horn retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); 4344b105cbbSOleg Nesterov task_unlock(task); 4351da177e4SLinus Torvalds if (retval) 4364b105cbbSOleg Nesterov goto unlock_creds; 4371da177e4SLinus Torvalds 4384b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 439b79b7ba9SOleg Nesterov retval = -EPERM; 440b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 4414b105cbbSOleg Nesterov goto unlock_tasklist; 442f2f0b00aSOleg Nesterov if (task->ptrace) 4434b105cbbSOleg Nesterov goto unlock_tasklist; 444b79b7ba9SOleg Nesterov 445aa9147c9SDenys Vlasenko task->ptrace = flags; 4461da177e4SLinus Torvalds 447c70d9d80SEric W. Biederman ptrace_link(task, current); 4483544d72aSTejun Heo 4493544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 4503544d72aSTejun Heo if (!seize) 451079b22dcSEric W. Biederman send_sig_info(SIGSTOP, SEND_SIG_PRIV, task); 452b79b7ba9SOleg Nesterov 453d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 454d79fdd6dSTejun Heo 455d79fdd6dSTejun Heo /* 45673ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 457d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 458d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 459d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 460d79fdd6dSTejun Heo * for the transition to complete before returning from this 461d79fdd6dSTejun Heo * function. 462d79fdd6dSTejun Heo * 463d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 464d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 465d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 466d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 467d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 468d79fdd6dSTejun Heo * 469d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 470d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 471d79fdd6dSTejun Heo */ 4727dd3db54STejun Heo if (task_is_stopped(task) && 47331cae1eaSPeter Zijlstra task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) { 47431cae1eaSPeter Zijlstra task->jobctl &= ~JOBCTL_STOPPED; 475910ffdb1SOleg Nesterov signal_wake_up_state(task, __TASK_STOPPED); 47631cae1eaSPeter Zijlstra } 477d79fdd6dSTejun Heo 478d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 479d79fdd6dSTejun Heo 480b79b7ba9SOleg Nesterov retval = 0; 4814b105cbbSOleg Nesterov unlock_tasklist: 4824b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 4834b105cbbSOleg Nesterov unlock_creds: 4849b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 485f5b40e36SLinus Torvalds out: 486f701e5b7SVladimir Zapolskiy if (!retval) { 4877c3b00e0SOleg Nesterov /* 4887c3b00e0SOleg Nesterov * We do not bother to change retval or clear JOBCTL_TRAPPING 4897c3b00e0SOleg Nesterov * if wait_on_bit() was interrupted by SIGKILL. The tracer will 4907c3b00e0SOleg Nesterov * not return to user-mode, it will exit and clear this bit in 4917c3b00e0SOleg Nesterov * __ptrace_unlink() if it wasn't already cleared by the tracee; 4927c3b00e0SOleg Nesterov * and until then nobody can ptrace this task. 4937c3b00e0SOleg Nesterov */ 4947c3b00e0SOleg Nesterov wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); 495f701e5b7SVladimir Zapolskiy proc_ptrace_connector(task, PTRACE_ATTACH); 496f701e5b7SVladimir Zapolskiy } 497f701e5b7SVladimir Zapolskiy 4981da177e4SLinus Torvalds return retval; 4991da177e4SLinus Torvalds } 5001da177e4SLinus Torvalds 501f2f0b00aSOleg Nesterov /** 502f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 503f2f0b00aSOleg Nesterov * 504f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 505f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 506f2f0b00aSOleg Nesterov */ 507e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 508f2f0b00aSOleg Nesterov { 509f2f0b00aSOleg Nesterov int ret = -EPERM; 510f2f0b00aSOleg Nesterov 5114b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 5124b105cbbSOleg Nesterov /* Are we already being traced? */ 513f2f0b00aSOleg Nesterov if (!current->ptrace) { 514f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 515f2f0b00aSOleg Nesterov /* 516f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 517f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 518f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 519f2f0b00aSOleg Nesterov */ 520f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 521f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 522c70d9d80SEric W. Biederman ptrace_link(current, current->real_parent); 523f2f0b00aSOleg Nesterov } 524f2f0b00aSOleg Nesterov } 5254b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 5264b105cbbSOleg Nesterov 527f2f0b00aSOleg Nesterov return ret; 528f2f0b00aSOleg Nesterov } 529f2f0b00aSOleg Nesterov 53039c626aeSOleg Nesterov /* 53139c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 53239c626aeSOleg Nesterov */ 53339c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 53439c626aeSOleg Nesterov { 53539c626aeSOleg Nesterov int ret; 53639c626aeSOleg Nesterov spin_lock(&sigh->siglock); 53739c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 53839c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 53939c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 54039c626aeSOleg Nesterov return ret; 54139c626aeSOleg Nesterov } 54239c626aeSOleg Nesterov 54339c626aeSOleg Nesterov /* 54439c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 54539c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 54639c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 54739c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 54839c626aeSOleg Nesterov * 54939c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 55039c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 55139c626aeSOleg Nesterov * If it should reap itself, return true. 55239c626aeSOleg Nesterov * 553a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 554a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 555a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 556a7f0765eSOleg Nesterov * do_wait(). 55739c626aeSOleg Nesterov */ 55839c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 55939c626aeSOleg Nesterov { 5609843a1e9SOleg Nesterov bool dead; 5619843a1e9SOleg Nesterov 56239c626aeSOleg Nesterov __ptrace_unlink(p); 56339c626aeSOleg Nesterov 5649843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 5659843a1e9SOleg Nesterov return false; 5669843a1e9SOleg Nesterov 5679843a1e9SOleg Nesterov dead = !thread_group_leader(p); 5689843a1e9SOleg Nesterov 5699843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 57039c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 5719843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 572a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 573a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 5749843a1e9SOleg Nesterov dead = true; 57539c626aeSOleg Nesterov } 576a7f0765eSOleg Nesterov } 57739c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 5789843a1e9SOleg Nesterov if (dead) 57939c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 5809843a1e9SOleg Nesterov return dead; 58139c626aeSOleg Nesterov } 58239c626aeSOleg Nesterov 583e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 5841da177e4SLinus Torvalds { 5857ed20e1aSJesper Juhl if (!valid_signal(data)) 5861da177e4SLinus Torvalds return -EIO; 5871da177e4SLinus Torvalds 5881da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 5891da177e4SLinus Torvalds ptrace_disable(child); 5901da177e4SLinus Torvalds 59195c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 59239c626aeSOleg Nesterov /* 59364a4096cSOleg Nesterov * We rely on ptrace_freeze_traced(). It can't be killed and 59464a4096cSOleg Nesterov * untraced by another thread, it can't be a zombie. 59539c626aeSOleg Nesterov */ 59664a4096cSOleg Nesterov WARN_ON(!child->ptrace || child->exit_state); 59764a4096cSOleg Nesterov /* 59864a4096cSOleg Nesterov * tasklist_lock avoids the race with wait_task_stopped(), see 59964a4096cSOleg Nesterov * the comment in ptrace_resume(). 60064a4096cSOleg Nesterov */ 60195c3eb76SOleg Nesterov child->exit_code = data; 60264a4096cSOleg Nesterov __ptrace_detach(current, child); 6031da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 6041da177e4SLinus Torvalds 605f701e5b7SVladimir Zapolskiy proc_ptrace_connector(child, PTRACE_DETACH); 6064576145cSOleg Nesterov 6071da177e4SLinus Torvalds return 0; 6081da177e4SLinus Torvalds } 6091da177e4SLinus Torvalds 61039c626aeSOleg Nesterov /* 611c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 6127c8bd232SOleg Nesterov * for writing. 61339c626aeSOleg Nesterov */ 6147c8bd232SOleg Nesterov void exit_ptrace(struct task_struct *tracer, struct list_head *dead) 61539c626aeSOleg Nesterov { 61639c626aeSOleg Nesterov struct task_struct *p, *n; 617c7e49c14SOleg Nesterov 61839c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 619992fb6e1SOleg Nesterov if (unlikely(p->ptrace & PT_EXITKILL)) 620079b22dcSEric W. Biederman send_sig_info(SIGKILL, SEND_SIG_PRIV, p); 621992fb6e1SOleg Nesterov 62239c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 6237c8bd232SOleg Nesterov list_add(&p->ptrace_entry, dead); 62439c626aeSOleg Nesterov } 62539c626aeSOleg Nesterov } 62639c626aeSOleg Nesterov 6271da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 6281da177e4SLinus Torvalds { 6291da177e4SLinus Torvalds int copied = 0; 6301da177e4SLinus Torvalds 6311da177e4SLinus Torvalds while (len > 0) { 6321da177e4SLinus Torvalds char buf[128]; 6331da177e4SLinus Torvalds int this_len, retval; 6341da177e4SLinus Torvalds 6351da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 63684d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE); 63784d77d3fSEric W. Biederman 6381da177e4SLinus Torvalds if (!retval) { 6391da177e4SLinus Torvalds if (copied) 6401da177e4SLinus Torvalds break; 6411da177e4SLinus Torvalds return -EIO; 6421da177e4SLinus Torvalds } 6431da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 6441da177e4SLinus Torvalds return -EFAULT; 6451da177e4SLinus Torvalds copied += retval; 6461da177e4SLinus Torvalds src += retval; 6471da177e4SLinus Torvalds dst += retval; 6481da177e4SLinus Torvalds len -= retval; 6491da177e4SLinus Torvalds } 6501da177e4SLinus Torvalds return copied; 6511da177e4SLinus Torvalds } 6521da177e4SLinus Torvalds 6531da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 6541da177e4SLinus Torvalds { 6551da177e4SLinus Torvalds int copied = 0; 6561da177e4SLinus Torvalds 6571da177e4SLinus Torvalds while (len > 0) { 6581da177e4SLinus Torvalds char buf[128]; 6591da177e4SLinus Torvalds int this_len, retval; 6601da177e4SLinus Torvalds 6611da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 6621da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 6631da177e4SLinus Torvalds return -EFAULT; 66484d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, dst, buf, this_len, 665f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 6661da177e4SLinus Torvalds if (!retval) { 6671da177e4SLinus Torvalds if (copied) 6681da177e4SLinus Torvalds break; 6691da177e4SLinus Torvalds return -EIO; 6701da177e4SLinus Torvalds } 6711da177e4SLinus Torvalds copied += retval; 6721da177e4SLinus Torvalds src += retval; 6731da177e4SLinus Torvalds dst += retval; 6741da177e4SLinus Torvalds len -= retval; 6751da177e4SLinus Torvalds } 6761da177e4SLinus Torvalds return copied; 6771da177e4SLinus Torvalds } 6781da177e4SLinus Torvalds 6794abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 6801da177e4SLinus Torvalds { 68186b6c1f3SDenys Vlasenko unsigned flags; 682ee1fee90SJann Horn int ret; 68386b6c1f3SDenys Vlasenko 684ee1fee90SJann Horn ret = check_ptrace_options(data); 685ee1fee90SJann Horn if (ret) 686ee1fee90SJann Horn return ret; 68713c4a901STycho Andersen 68886b6c1f3SDenys Vlasenko /* Avoid intermediate state when all opts are cleared */ 68986b6c1f3SDenys Vlasenko flags = child->ptrace; 69086b6c1f3SDenys Vlasenko flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); 69186b6c1f3SDenys Vlasenko flags |= (data << PT_OPT_FLAG_SHIFT); 69286b6c1f3SDenys Vlasenko child->ptrace = flags; 6931da177e4SLinus Torvalds 6948c5cf9e5SDenys Vlasenko return 0; 6951da177e4SLinus Torvalds } 6961da177e4SLinus Torvalds 697ae7795bcSEric W. Biederman static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info) 6981da177e4SLinus Torvalds { 699e4961254SOleg Nesterov unsigned long flags; 7001da177e4SLinus Torvalds int error = -ESRCH; 7011da177e4SLinus Torvalds 702e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 7031da177e4SLinus Torvalds error = -EINVAL; 7041da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 7050752d7bfSEric W. Biederman copy_siginfo(info, child->last_siginfo); 7061da177e4SLinus Torvalds error = 0; 7071da177e4SLinus Torvalds } 708e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 7091da177e4SLinus Torvalds } 7101da177e4SLinus Torvalds return error; 7111da177e4SLinus Torvalds } 7121da177e4SLinus Torvalds 713ae7795bcSEric W. Biederman static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info) 7141da177e4SLinus Torvalds { 715e4961254SOleg Nesterov unsigned long flags; 7161da177e4SLinus Torvalds int error = -ESRCH; 7171da177e4SLinus Torvalds 718e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 7191da177e4SLinus Torvalds error = -EINVAL; 7201da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 7210752d7bfSEric W. Biederman copy_siginfo(child->last_siginfo, info); 7221da177e4SLinus Torvalds error = 0; 7231da177e4SLinus Torvalds } 724e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 7251da177e4SLinus Torvalds } 7261da177e4SLinus Torvalds return error; 7271da177e4SLinus Torvalds } 7281da177e4SLinus Torvalds 72984c751bdSAndrey Vagin static int ptrace_peek_siginfo(struct task_struct *child, 73084c751bdSAndrey Vagin unsigned long addr, 73184c751bdSAndrey Vagin unsigned long data) 73284c751bdSAndrey Vagin { 73384c751bdSAndrey Vagin struct ptrace_peeksiginfo_args arg; 73484c751bdSAndrey Vagin struct sigpending *pending; 73584c751bdSAndrey Vagin struct sigqueue *q; 73684c751bdSAndrey Vagin int ret, i; 73784c751bdSAndrey Vagin 73884c751bdSAndrey Vagin ret = copy_from_user(&arg, (void __user *) addr, 73984c751bdSAndrey Vagin sizeof(struct ptrace_peeksiginfo_args)); 74084c751bdSAndrey Vagin if (ret) 74184c751bdSAndrey Vagin return -EFAULT; 74284c751bdSAndrey Vagin 74384c751bdSAndrey Vagin if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) 74484c751bdSAndrey Vagin return -EINVAL; /* unknown flags */ 74584c751bdSAndrey Vagin 74684c751bdSAndrey Vagin if (arg.nr < 0) 74784c751bdSAndrey Vagin return -EINVAL; 74884c751bdSAndrey Vagin 749f6e2aa91SEric W. Biederman /* Ensure arg.off fits in an unsigned long */ 750f6e2aa91SEric W. Biederman if (arg.off > ULONG_MAX) 751f6e2aa91SEric W. Biederman return 0; 752f6e2aa91SEric W. Biederman 75384c751bdSAndrey Vagin if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) 75484c751bdSAndrey Vagin pending = &child->signal->shared_pending; 75584c751bdSAndrey Vagin else 75684c751bdSAndrey Vagin pending = &child->pending; 75784c751bdSAndrey Vagin 75884c751bdSAndrey Vagin for (i = 0; i < arg.nr; ) { 759ae7795bcSEric W. Biederman kernel_siginfo_t info; 760f6e2aa91SEric W. Biederman unsigned long off = arg.off + i; 761f6e2aa91SEric W. Biederman bool found = false; 76284c751bdSAndrey Vagin 76384c751bdSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 76484c751bdSAndrey Vagin list_for_each_entry(q, &pending->list, list) { 76584c751bdSAndrey Vagin if (!off--) { 766f6e2aa91SEric W. Biederman found = true; 76784c751bdSAndrey Vagin copy_siginfo(&info, &q->info); 76884c751bdSAndrey Vagin break; 76984c751bdSAndrey Vagin } 77084c751bdSAndrey Vagin } 77184c751bdSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 77284c751bdSAndrey Vagin 773f6e2aa91SEric W. Biederman if (!found) /* beyond the end of the list */ 77484c751bdSAndrey Vagin break; 77584c751bdSAndrey Vagin 77684c751bdSAndrey Vagin #ifdef CONFIG_COMPAT 7775c465217SAndy Lutomirski if (unlikely(in_compat_syscall())) { 77884c751bdSAndrey Vagin compat_siginfo_t __user *uinfo = compat_ptr(data); 77984c751bdSAndrey Vagin 780cc731525SEric W. Biederman if (copy_siginfo_to_user32(uinfo, &info)) { 781706b23bdSMathieu Desnoyers ret = -EFAULT; 782706b23bdSMathieu Desnoyers break; 783706b23bdSMathieu Desnoyers } 784706b23bdSMathieu Desnoyers 78584c751bdSAndrey Vagin } else 78684c751bdSAndrey Vagin #endif 78784c751bdSAndrey Vagin { 78884c751bdSAndrey Vagin siginfo_t __user *uinfo = (siginfo_t __user *) data; 78984c751bdSAndrey Vagin 790cc731525SEric W. Biederman if (copy_siginfo_to_user(uinfo, &info)) { 79184c751bdSAndrey Vagin ret = -EFAULT; 79284c751bdSAndrey Vagin break; 79384c751bdSAndrey Vagin } 794706b23bdSMathieu Desnoyers } 79584c751bdSAndrey Vagin 79684c751bdSAndrey Vagin data += sizeof(siginfo_t); 79784c751bdSAndrey Vagin i++; 79884c751bdSAndrey Vagin 79984c751bdSAndrey Vagin if (signal_pending(current)) 80084c751bdSAndrey Vagin break; 80184c751bdSAndrey Vagin 80284c751bdSAndrey Vagin cond_resched(); 80384c751bdSAndrey Vagin } 80484c751bdSAndrey Vagin 80584c751bdSAndrey Vagin if (i > 0) 80684c751bdSAndrey Vagin return i; 80784c751bdSAndrey Vagin 80884c751bdSAndrey Vagin return ret; 80984c751bdSAndrey Vagin } 81036df29d7SRoland McGrath 81190f093faSPiotr Figiel #ifdef CONFIG_RSEQ 81290f093faSPiotr Figiel static long ptrace_get_rseq_configuration(struct task_struct *task, 81390f093faSPiotr Figiel unsigned long size, void __user *data) 81490f093faSPiotr Figiel { 81590f093faSPiotr Figiel struct ptrace_rseq_configuration conf = { 81690f093faSPiotr Figiel .rseq_abi_pointer = (u64)(uintptr_t)task->rseq, 817ee3e3ac0SMathieu Desnoyers .rseq_abi_size = task->rseq_len, 81890f093faSPiotr Figiel .signature = task->rseq_sig, 81990f093faSPiotr Figiel .flags = 0, 82090f093faSPiotr Figiel }; 82190f093faSPiotr Figiel 82290f093faSPiotr Figiel size = min_t(unsigned long, size, sizeof(conf)); 82390f093faSPiotr Figiel if (copy_to_user(data, &conf, size)) 82490f093faSPiotr Figiel return -EFAULT; 82590f093faSPiotr Figiel return sizeof(conf); 82690f093faSPiotr Figiel } 82790f093faSPiotr Figiel #endif 82890f093faSPiotr Figiel 82936df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 83036df29d7SRoland McGrath 8315b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 8325b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 8335b88abbfSRoland McGrath #else 8345b88abbfSRoland McGrath #define is_singleblock(request) 0 8355b88abbfSRoland McGrath #endif 8365b88abbfSRoland McGrath 83736df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 83836df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 83936df29d7SRoland McGrath #else 84036df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 84136df29d7SRoland McGrath #endif 84236df29d7SRoland McGrath 8434abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 8444abf9869SNamhyung Kim unsigned long data) 84536df29d7SRoland McGrath { 84636df29d7SRoland McGrath if (!valid_signal(data)) 84736df29d7SRoland McGrath return -EIO; 84836df29d7SRoland McGrath 84936df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 85064c19ba2SGabriel Krisman Bertazi set_task_syscall_work(child, SYSCALL_TRACE); 85136df29d7SRoland McGrath else 85264c19ba2SGabriel Krisman Bertazi clear_task_syscall_work(child, SYSCALL_TRACE); 85336df29d7SRoland McGrath 85464eb35f7SGabriel Krisman Bertazi #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) 85536df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 85664eb35f7SGabriel Krisman Bertazi set_task_syscall_work(child, SYSCALL_EMU); 85736df29d7SRoland McGrath else 85864eb35f7SGabriel Krisman Bertazi clear_task_syscall_work(child, SYSCALL_EMU); 85936df29d7SRoland McGrath #endif 86036df29d7SRoland McGrath 8615b88abbfSRoland McGrath if (is_singleblock(request)) { 8625b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 8635b88abbfSRoland McGrath return -EIO; 8645b88abbfSRoland McGrath user_enable_block_step(child); 8655b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 86636df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 86736df29d7SRoland McGrath return -EIO; 86836df29d7SRoland McGrath user_enable_single_step(child); 8693a709703SRoland McGrath } else { 87036df29d7SRoland McGrath user_disable_single_step(child); 8713a709703SRoland McGrath } 87236df29d7SRoland McGrath 873b72c1869SOleg Nesterov /* 874b72c1869SOleg Nesterov * Change ->exit_code and ->state under siglock to avoid the race 875b72c1869SOleg Nesterov * with wait_task_stopped() in between; a non-zero ->exit_code will 876b72c1869SOleg Nesterov * wrongly look like another report from tracee. 877b72c1869SOleg Nesterov * 878b72c1869SOleg Nesterov * Note that we need siglock even if ->exit_code == data and/or this 879b72c1869SOleg Nesterov * status was not reported yet, the new status must not be cleared by 880b72c1869SOleg Nesterov * wait_task_stopped() after resume. 881b72c1869SOleg Nesterov */ 882b72c1869SOleg Nesterov spin_lock_irq(&child->sighand->siglock); 88336df29d7SRoland McGrath child->exit_code = data; 88431cae1eaSPeter Zijlstra child->jobctl &= ~JOBCTL_TRACED; 8850666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 886b72c1869SOleg Nesterov spin_unlock_irq(&child->sighand->siglock); 88736df29d7SRoland McGrath 88836df29d7SRoland McGrath return 0; 88936df29d7SRoland McGrath } 89036df29d7SRoland McGrath 8912225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8922225a122SSuresh Siddha 8932225a122SSuresh Siddha static const struct user_regset * 8942225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 8952225a122SSuresh Siddha { 8962225a122SSuresh Siddha const struct user_regset *regset; 8972225a122SSuresh Siddha int n; 8982225a122SSuresh Siddha 8992225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 9002225a122SSuresh Siddha regset = view->regsets + n; 9012225a122SSuresh Siddha if (regset->core_note_type == type) 9022225a122SSuresh Siddha return regset; 9032225a122SSuresh Siddha } 9042225a122SSuresh Siddha 9052225a122SSuresh Siddha return NULL; 9062225a122SSuresh Siddha } 9072225a122SSuresh Siddha 9082225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 9092225a122SSuresh Siddha struct iovec *kiov) 9102225a122SSuresh Siddha { 9112225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 9122225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 9132225a122SSuresh Siddha int regset_no; 9142225a122SSuresh Siddha 9152225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 916c6a0dd7eSSuresh Siddha return -EINVAL; 9172225a122SSuresh Siddha 9182225a122SSuresh Siddha regset_no = regset - view->regsets; 9192225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 9202225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 9212225a122SSuresh Siddha 9222225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 9232225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 9242225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 9252225a122SSuresh Siddha else 9262225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 9272225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 9282225a122SSuresh Siddha } 9292225a122SSuresh Siddha 930e8440c14SJosh Stone /* 931e8440c14SJosh Stone * This is declared in linux/regset.h and defined in machine-dependent 932e8440c14SJosh Stone * code. We put the export here, near the primary machine-neutral use, 933e8440c14SJosh Stone * to ensure no machine forgets it. 934e8440c14SJosh Stone */ 935e8440c14SJosh Stone EXPORT_SYMBOL_GPL(task_user_regset_view); 936201766a2SElvira Khabirova 937201766a2SElvira Khabirova static unsigned long 938201766a2SElvira Khabirova ptrace_get_syscall_info_entry(struct task_struct *child, struct pt_regs *regs, 939201766a2SElvira Khabirova struct ptrace_syscall_info *info) 940201766a2SElvira Khabirova { 941201766a2SElvira Khabirova unsigned long args[ARRAY_SIZE(info->entry.args)]; 942201766a2SElvira Khabirova int i; 943201766a2SElvira Khabirova 944201766a2SElvira Khabirova info->op = PTRACE_SYSCALL_INFO_ENTRY; 945201766a2SElvira Khabirova info->entry.nr = syscall_get_nr(child, regs); 946201766a2SElvira Khabirova syscall_get_arguments(child, regs, args); 947201766a2SElvira Khabirova for (i = 0; i < ARRAY_SIZE(args); i++) 948201766a2SElvira Khabirova info->entry.args[i] = args[i]; 949201766a2SElvira Khabirova 950201766a2SElvira Khabirova /* args is the last field in struct ptrace_syscall_info.entry */ 951201766a2SElvira Khabirova return offsetofend(struct ptrace_syscall_info, entry.args); 952201766a2SElvira Khabirova } 953201766a2SElvira Khabirova 954201766a2SElvira Khabirova static unsigned long 955201766a2SElvira Khabirova ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs, 956201766a2SElvira Khabirova struct ptrace_syscall_info *info) 957201766a2SElvira Khabirova { 958201766a2SElvira Khabirova /* 959201766a2SElvira Khabirova * As struct ptrace_syscall_info.entry is currently a subset 960201766a2SElvira Khabirova * of struct ptrace_syscall_info.seccomp, it makes sense to 961201766a2SElvira Khabirova * initialize that subset using ptrace_get_syscall_info_entry(). 962201766a2SElvira Khabirova * This can be reconsidered in the future if these structures 963201766a2SElvira Khabirova * diverge significantly enough. 964201766a2SElvira Khabirova */ 965201766a2SElvira Khabirova ptrace_get_syscall_info_entry(child, regs, info); 966201766a2SElvira Khabirova info->op = PTRACE_SYSCALL_INFO_SECCOMP; 967201766a2SElvira Khabirova info->seccomp.ret_data = child->ptrace_message; 968201766a2SElvira Khabirova 969201766a2SElvira Khabirova /* ret_data is the last field in struct ptrace_syscall_info.seccomp */ 970201766a2SElvira Khabirova return offsetofend(struct ptrace_syscall_info, seccomp.ret_data); 971201766a2SElvira Khabirova } 972201766a2SElvira Khabirova 973201766a2SElvira Khabirova static unsigned long 974201766a2SElvira Khabirova ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs, 975201766a2SElvira Khabirova struct ptrace_syscall_info *info) 976201766a2SElvira Khabirova { 977201766a2SElvira Khabirova info->op = PTRACE_SYSCALL_INFO_EXIT; 978201766a2SElvira Khabirova info->exit.rval = syscall_get_error(child, regs); 979201766a2SElvira Khabirova info->exit.is_error = !!info->exit.rval; 980201766a2SElvira Khabirova if (!info->exit.is_error) 981201766a2SElvira Khabirova info->exit.rval = syscall_get_return_value(child, regs); 982201766a2SElvira Khabirova 983201766a2SElvira Khabirova /* is_error is the last field in struct ptrace_syscall_info.exit */ 984201766a2SElvira Khabirova return offsetofend(struct ptrace_syscall_info, exit.is_error); 985201766a2SElvira Khabirova } 986201766a2SElvira Khabirova 987201766a2SElvira Khabirova static int 988201766a2SElvira Khabirova ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size, 989201766a2SElvira Khabirova void __user *datavp) 990201766a2SElvira Khabirova { 991201766a2SElvira Khabirova struct pt_regs *regs = task_pt_regs(child); 992201766a2SElvira Khabirova struct ptrace_syscall_info info = { 993201766a2SElvira Khabirova .op = PTRACE_SYSCALL_INFO_NONE, 994201766a2SElvira Khabirova .arch = syscall_get_arch(child), 995201766a2SElvira Khabirova .instruction_pointer = instruction_pointer(regs), 996201766a2SElvira Khabirova .stack_pointer = user_stack_pointer(regs), 997201766a2SElvira Khabirova }; 998201766a2SElvira Khabirova unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry); 999201766a2SElvira Khabirova unsigned long write_size; 1000201766a2SElvira Khabirova 1001201766a2SElvira Khabirova /* 1002201766a2SElvira Khabirova * This does not need lock_task_sighand() to access 1003201766a2SElvira Khabirova * child->last_siginfo because ptrace_freeze_traced() 1004201766a2SElvira Khabirova * called earlier by ptrace_check_attach() ensures that 1005201766a2SElvira Khabirova * the tracee cannot go away and clear its last_siginfo. 1006201766a2SElvira Khabirova */ 1007201766a2SElvira Khabirova switch (child->last_siginfo ? child->last_siginfo->si_code : 0) { 1008201766a2SElvira Khabirova case SIGTRAP | 0x80: 1009201766a2SElvira Khabirova switch (child->ptrace_message) { 1010201766a2SElvira Khabirova case PTRACE_EVENTMSG_SYSCALL_ENTRY: 1011201766a2SElvira Khabirova actual_size = ptrace_get_syscall_info_entry(child, regs, 1012201766a2SElvira Khabirova &info); 1013201766a2SElvira Khabirova break; 1014201766a2SElvira Khabirova case PTRACE_EVENTMSG_SYSCALL_EXIT: 1015201766a2SElvira Khabirova actual_size = ptrace_get_syscall_info_exit(child, regs, 1016201766a2SElvira Khabirova &info); 1017201766a2SElvira Khabirova break; 1018201766a2SElvira Khabirova } 1019201766a2SElvira Khabirova break; 1020201766a2SElvira Khabirova case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8): 1021201766a2SElvira Khabirova actual_size = ptrace_get_syscall_info_seccomp(child, regs, 1022201766a2SElvira Khabirova &info); 1023201766a2SElvira Khabirova break; 1024201766a2SElvira Khabirova } 1025201766a2SElvira Khabirova 1026201766a2SElvira Khabirova write_size = min(actual_size, user_size); 1027201766a2SElvira Khabirova return copy_to_user(datavp, &info, write_size) ? -EFAULT : actual_size; 1028201766a2SElvira Khabirova } 1029201766a2SElvira Khabirova #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 10302225a122SSuresh Siddha 10311da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 10324abf9869SNamhyung Kim unsigned long addr, unsigned long data) 10331da177e4SLinus Torvalds { 1034fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 10351da177e4SLinus Torvalds int ret = -EIO; 1036ae7795bcSEric W. Biederman kernel_siginfo_t siginfo, *si; 10379fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 10389fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 1039fca26f26STejun Heo unsigned long flags; 10401da177e4SLinus Torvalds 10411da177e4SLinus Torvalds switch (request) { 104216c3e389SRoland McGrath case PTRACE_PEEKTEXT: 104316c3e389SRoland McGrath case PTRACE_PEEKDATA: 104416c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 104516c3e389SRoland McGrath case PTRACE_POKETEXT: 104616c3e389SRoland McGrath case PTRACE_POKEDATA: 104716c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 104816c3e389SRoland McGrath 10491da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 10501da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 10511da177e4SLinus Torvalds #endif 10521da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 10531da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 10541da177e4SLinus Torvalds break; 10551da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 10569fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 10571da177e4SLinus Torvalds break; 1058e16b2781SRoland McGrath 105984c751bdSAndrey Vagin case PTRACE_PEEKSIGINFO: 106084c751bdSAndrey Vagin ret = ptrace_peek_siginfo(child, addr, data); 106184c751bdSAndrey Vagin break; 106284c751bdSAndrey Vagin 10631da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 1064e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 1065e16b2781SRoland McGrath if (!ret) 10669fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 10671da177e4SLinus Torvalds break; 1068e16b2781SRoland McGrath 10691da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 10704cd2e0e7SEric W. Biederman ret = copy_siginfo_from_user(&siginfo, datavp); 10714cd2e0e7SEric W. Biederman if (!ret) 1072e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 10731da177e4SLinus Torvalds break; 1074e16b2781SRoland McGrath 1075fcfc2aa0SAndrei Vagin case PTRACE_GETSIGMASK: { 1076fcfc2aa0SAndrei Vagin sigset_t *mask; 1077fcfc2aa0SAndrei Vagin 107829000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 107929000caeSAndrey Vagin ret = -EINVAL; 108029000caeSAndrey Vagin break; 108129000caeSAndrey Vagin } 108229000caeSAndrey Vagin 1083fcfc2aa0SAndrei Vagin if (test_tsk_restore_sigmask(child)) 1084fcfc2aa0SAndrei Vagin mask = &child->saved_sigmask; 1085fcfc2aa0SAndrei Vagin else 1086fcfc2aa0SAndrei Vagin mask = &child->blocked; 1087fcfc2aa0SAndrei Vagin 1088fcfc2aa0SAndrei Vagin if (copy_to_user(datavp, mask, sizeof(sigset_t))) 108929000caeSAndrey Vagin ret = -EFAULT; 109029000caeSAndrey Vagin else 109129000caeSAndrey Vagin ret = 0; 109229000caeSAndrey Vagin 109329000caeSAndrey Vagin break; 1094fcfc2aa0SAndrei Vagin } 109529000caeSAndrey Vagin 109629000caeSAndrey Vagin case PTRACE_SETSIGMASK: { 109729000caeSAndrey Vagin sigset_t new_set; 109829000caeSAndrey Vagin 109929000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 110029000caeSAndrey Vagin ret = -EINVAL; 110129000caeSAndrey Vagin break; 110229000caeSAndrey Vagin } 110329000caeSAndrey Vagin 110429000caeSAndrey Vagin if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { 110529000caeSAndrey Vagin ret = -EFAULT; 110629000caeSAndrey Vagin break; 110729000caeSAndrey Vagin } 110829000caeSAndrey Vagin 110929000caeSAndrey Vagin sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); 111029000caeSAndrey Vagin 111129000caeSAndrey Vagin /* 111229000caeSAndrey Vagin * Every thread does recalc_sigpending() after resume, so 111329000caeSAndrey Vagin * retarget_shared_pending() and recalc_sigpending() are not 111429000caeSAndrey Vagin * called here. 111529000caeSAndrey Vagin */ 111629000caeSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 111729000caeSAndrey Vagin child->blocked = new_set; 111829000caeSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 111929000caeSAndrey Vagin 1120fcfc2aa0SAndrei Vagin clear_tsk_restore_sigmask(child); 1121fcfc2aa0SAndrei Vagin 112229000caeSAndrey Vagin ret = 0; 112329000caeSAndrey Vagin break; 112429000caeSAndrey Vagin } 112529000caeSAndrey Vagin 1126fca26f26STejun Heo case PTRACE_INTERRUPT: 1127fca26f26STejun Heo /* 1128fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 1129fca26f26STejun Heo * control. At least one trap is guaranteed to happen 1130fca26f26STejun Heo * after this request. If @child is already trapped, the 1131fca26f26STejun Heo * current trap is not disturbed and another trap will 1132fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 1133fca26f26STejun Heo * 1134fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 1135fca26f26STejun Heo * the pending condition is cleared regardless. 1136fca26f26STejun Heo */ 1137fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 1138fca26f26STejun Heo break; 1139fca26f26STejun Heo 1140544b2c91STejun Heo /* 1141544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 1142544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 1143544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 1144544b2c91STejun Heo * tracee into STOP. 1145544b2c91STejun Heo */ 1146fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 1147910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 1148544b2c91STejun Heo 1149544b2c91STejun Heo unlock_task_sighand(child, &flags); 1150544b2c91STejun Heo ret = 0; 1151544b2c91STejun Heo break; 1152544b2c91STejun Heo 1153544b2c91STejun Heo case PTRACE_LISTEN: 1154544b2c91STejun Heo /* 1155544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 1156544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 1157544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 1158544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 1159544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 1160544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 1161544b2c91STejun Heo */ 1162544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 1163544b2c91STejun Heo break; 1164544b2c91STejun Heo 1165544b2c91STejun Heo si = child->last_siginfo; 1166f9d81f61SOleg Nesterov if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { 1167544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 1168544b2c91STejun Heo /* 1169f9d81f61SOleg Nesterov * If NOTIFY is set, it means event happened between 1170f9d81f61SOleg Nesterov * start of this trap and now. Trigger re-trap. 1171544b2c91STejun Heo */ 1172544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 1173910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 1174fca26f26STejun Heo ret = 0; 1175f9d81f61SOleg Nesterov } 1176f9d81f61SOleg Nesterov unlock_task_sighand(child, &flags); 1177fca26f26STejun Heo break; 1178fca26f26STejun Heo 11791bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 11801bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 11811bcf5482SAlexey Dobriyan break; 118236df29d7SRoland McGrath 11839c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 11849c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 1185e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 11869c1a1259SMike Frysinger unsigned long tmp = 0; 11879c1a1259SMike Frysinger 1188e0129ef9SOleg Nesterov ret = -ESRCH; 1189e0129ef9SOleg Nesterov if (!mm) 1190e0129ef9SOleg Nesterov break; 1191e0129ef9SOleg Nesterov 11929c1a1259SMike Frysinger switch (addr) { 11939c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 1194e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 11959c1a1259SMike Frysinger break; 11969c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 1197e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 11989c1a1259SMike Frysinger break; 11999c1a1259SMike Frysinger default: 12009c1a1259SMike Frysinger break; 12019c1a1259SMike Frysinger } 1202e0129ef9SOleg Nesterov mmput(mm); 12039c1a1259SMike Frysinger 12049fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 12059c1a1259SMike Frysinger break; 12069c1a1259SMike Frysinger } 12079c1a1259SMike Frysinger #endif 12089c1a1259SMike Frysinger 120936df29d7SRoland McGrath case PTRACE_SINGLESTEP: 12105b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 12115b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 12125b88abbfSRoland McGrath #endif 121336df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 121436df29d7SRoland McGrath case PTRACE_SYSEMU: 121536df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 121636df29d7SRoland McGrath #endif 121736df29d7SRoland McGrath case PTRACE_SYSCALL: 121836df29d7SRoland McGrath case PTRACE_CONT: 121936df29d7SRoland McGrath return ptrace_resume(child, request, data); 122036df29d7SRoland McGrath 122136df29d7SRoland McGrath case PTRACE_KILL: 12226a2d90baSEric W. Biederman send_sig_info(SIGKILL, SEND_SIG_NOINFO, child); 122336df29d7SRoland McGrath return 0; 122436df29d7SRoland McGrath 12252225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 12262225a122SSuresh Siddha case PTRACE_GETREGSET: 122729000caeSAndrey Vagin case PTRACE_SETREGSET: { 12282225a122SSuresh Siddha struct iovec kiov; 12299fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 12302225a122SSuresh Siddha 123196d4f267SLinus Torvalds if (!access_ok(uiov, sizeof(*uiov))) 12322225a122SSuresh Siddha return -EFAULT; 12332225a122SSuresh Siddha 12342225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 12352225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 12362225a122SSuresh Siddha return -EFAULT; 12372225a122SSuresh Siddha 12382225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 12392225a122SSuresh Siddha if (!ret) 12402225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 12412225a122SSuresh Siddha break; 12422225a122SSuresh Siddha } 1243201766a2SElvira Khabirova 1244201766a2SElvira Khabirova case PTRACE_GET_SYSCALL_INFO: 1245201766a2SElvira Khabirova ret = ptrace_get_syscall_info(child, addr, datavp); 1246201766a2SElvira Khabirova break; 12472225a122SSuresh Siddha #endif 1248f8e529edSTycho Andersen 1249f8e529edSTycho Andersen case PTRACE_SECCOMP_GET_FILTER: 1250f8e529edSTycho Andersen ret = seccomp_get_filter(child, addr, datavp); 1251f8e529edSTycho Andersen break; 1252f8e529edSTycho Andersen 125326500475STycho Andersen case PTRACE_SECCOMP_GET_METADATA: 125426500475STycho Andersen ret = seccomp_get_metadata(child, addr, datavp); 125526500475STycho Andersen break; 125626500475STycho Andersen 125790f093faSPiotr Figiel #ifdef CONFIG_RSEQ 125890f093faSPiotr Figiel case PTRACE_GET_RSEQ_CONFIGURATION: 125990f093faSPiotr Figiel ret = ptrace_get_rseq_configuration(child, addr, datavp); 126090f093faSPiotr Figiel break; 126190f093faSPiotr Figiel #endif 126290f093faSPiotr Figiel 1263*3f67987cSGregory Price case PTRACE_SET_SYSCALL_USER_DISPATCH_CONFIG: 1264*3f67987cSGregory Price ret = syscall_user_dispatch_set_config(child, addr, datavp); 1265*3f67987cSGregory Price break; 1266*3f67987cSGregory Price 1267*3f67987cSGregory Price case PTRACE_GET_SYSCALL_USER_DISPATCH_CONFIG: 1268*3f67987cSGregory Price ret = syscall_user_dispatch_get_config(child, addr, datavp); 1269*3f67987cSGregory Price break; 1270*3f67987cSGregory Price 12711da177e4SLinus Torvalds default: 12721da177e4SLinus Torvalds break; 12731da177e4SLinus Torvalds } 12741da177e4SLinus Torvalds 12751da177e4SLinus Torvalds return ret; 12761da177e4SLinus Torvalds } 1277481bed45SChristoph Hellwig 12784abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 12794abf9869SNamhyung Kim unsigned long, data) 1280481bed45SChristoph Hellwig { 1281481bed45SChristoph Hellwig struct task_struct *child; 1282481bed45SChristoph Hellwig long ret; 1283481bed45SChristoph Hellwig 12846b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 12856b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 1286481bed45SChristoph Hellwig goto out; 12876b9c7ed8SChristoph Hellwig } 12886b9c7ed8SChristoph Hellwig 12892ee08260SMike Rapoport child = find_get_task_by_vpid(pid); 12902ee08260SMike Rapoport if (!child) { 12912ee08260SMike Rapoport ret = -ESRCH; 12926b9c7ed8SChristoph Hellwig goto out; 12936b9c7ed8SChristoph Hellwig } 1294481bed45SChristoph Hellwig 12953544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1296aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 1297005f18dfSChristoph Hellwig goto out_put_task_struct; 1298481bed45SChristoph Hellwig } 1299481bed45SChristoph Hellwig 1300fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1301fca26f26STejun Heo request == PTRACE_INTERRUPT); 1302481bed45SChristoph Hellwig if (ret < 0) 1303481bed45SChristoph Hellwig goto out_put_task_struct; 1304481bed45SChristoph Hellwig 1305481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 13069899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 13079899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 1308481bed45SChristoph Hellwig 1309481bed45SChristoph Hellwig out_put_task_struct: 1310481bed45SChristoph Hellwig put_task_struct(child); 1311481bed45SChristoph Hellwig out: 1312481bed45SChristoph Hellwig return ret; 1313481bed45SChristoph Hellwig } 131476647323SAlexey Dobriyan 13154abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 13164abf9869SNamhyung Kim unsigned long data) 131776647323SAlexey Dobriyan { 131876647323SAlexey Dobriyan unsigned long tmp; 131976647323SAlexey Dobriyan int copied; 132076647323SAlexey Dobriyan 132184d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); 132276647323SAlexey Dobriyan if (copied != sizeof(tmp)) 132376647323SAlexey Dobriyan return -EIO; 132476647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 132576647323SAlexey Dobriyan } 1326f284ce72SAlexey Dobriyan 13274abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 13284abf9869SNamhyung Kim unsigned long data) 1329f284ce72SAlexey Dobriyan { 1330f284ce72SAlexey Dobriyan int copied; 1331f284ce72SAlexey Dobriyan 133284d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &data, sizeof(data), 1333f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1334f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 1335f284ce72SAlexey Dobriyan } 1336032d82d9SRoland McGrath 133796b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 1338032d82d9SRoland McGrath 1339032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 1340032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 1341032d82d9SRoland McGrath { 1342032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 1343032d82d9SRoland McGrath compat_ulong_t word; 1344ae7795bcSEric W. Biederman kernel_siginfo_t siginfo; 1345032d82d9SRoland McGrath int ret; 1346032d82d9SRoland McGrath 1347032d82d9SRoland McGrath switch (request) { 1348032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 1349032d82d9SRoland McGrath case PTRACE_PEEKDATA: 135084d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &word, sizeof(word), 1351f307ab6dSLorenzo Stoakes FOLL_FORCE); 1352032d82d9SRoland McGrath if (ret != sizeof(word)) 1353032d82d9SRoland McGrath ret = -EIO; 1354032d82d9SRoland McGrath else 1355032d82d9SRoland McGrath ret = put_user(word, datap); 1356032d82d9SRoland McGrath break; 1357032d82d9SRoland McGrath 1358032d82d9SRoland McGrath case PTRACE_POKETEXT: 1359032d82d9SRoland McGrath case PTRACE_POKEDATA: 136084d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &data, sizeof(data), 1361f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1362032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 1363032d82d9SRoland McGrath break; 1364032d82d9SRoland McGrath 1365032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 1366032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 1367032d82d9SRoland McGrath break; 1368032d82d9SRoland McGrath 1369e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 1370e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 1371e16b2781SRoland McGrath if (!ret) 1372e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 1373e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 1374e16b2781SRoland McGrath &siginfo); 1375e16b2781SRoland McGrath break; 1376e16b2781SRoland McGrath 1377e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 13784cd2e0e7SEric W. Biederman ret = copy_siginfo_from_user32( 13794cd2e0e7SEric W. Biederman &siginfo, (struct compat_siginfo __user *) datap); 13804cd2e0e7SEric W. Biederman if (!ret) 1381e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 1382e16b2781SRoland McGrath break; 13832225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 13842225a122SSuresh Siddha case PTRACE_GETREGSET: 13852225a122SSuresh Siddha case PTRACE_SETREGSET: 13862225a122SSuresh Siddha { 13872225a122SSuresh Siddha struct iovec kiov; 13882225a122SSuresh Siddha struct compat_iovec __user *uiov = 13892225a122SSuresh Siddha (struct compat_iovec __user *) datap; 13902225a122SSuresh Siddha compat_uptr_t ptr; 13912225a122SSuresh Siddha compat_size_t len; 13922225a122SSuresh Siddha 139396d4f267SLinus Torvalds if (!access_ok(uiov, sizeof(*uiov))) 13942225a122SSuresh Siddha return -EFAULT; 13952225a122SSuresh Siddha 13962225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 13972225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 13982225a122SSuresh Siddha return -EFAULT; 13992225a122SSuresh Siddha 14002225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 14012225a122SSuresh Siddha kiov.iov_len = len; 14022225a122SSuresh Siddha 14032225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 14042225a122SSuresh Siddha if (!ret) 14052225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 14062225a122SSuresh Siddha break; 14072225a122SSuresh Siddha } 14082225a122SSuresh Siddha #endif 1409e16b2781SRoland McGrath 1410032d82d9SRoland McGrath default: 1411032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 1412032d82d9SRoland McGrath } 1413032d82d9SRoland McGrath 1414032d82d9SRoland McGrath return ret; 1415032d82d9SRoland McGrath } 1416c269f196SRoland McGrath 141762a6fa97SHeiko Carstens COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, 141862a6fa97SHeiko Carstens compat_long_t, addr, compat_long_t, data) 1419c269f196SRoland McGrath { 1420c269f196SRoland McGrath struct task_struct *child; 1421c269f196SRoland McGrath long ret; 1422c269f196SRoland McGrath 1423c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1424c269f196SRoland McGrath ret = ptrace_traceme(); 1425c269f196SRoland McGrath goto out; 1426c269f196SRoland McGrath } 1427c269f196SRoland McGrath 14282ee08260SMike Rapoport child = find_get_task_by_vpid(pid); 14292ee08260SMike Rapoport if (!child) { 14302ee08260SMike Rapoport ret = -ESRCH; 1431c269f196SRoland McGrath goto out; 1432c269f196SRoland McGrath } 1433c269f196SRoland McGrath 14343544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1435aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 1436c269f196SRoland McGrath goto out_put_task_struct; 1437c269f196SRoland McGrath } 1438c269f196SRoland McGrath 1439fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1440fca26f26STejun Heo request == PTRACE_INTERRUPT); 14419899d11fSOleg Nesterov if (!ret) { 1442c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 14439899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 14449899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 14459899d11fSOleg Nesterov } 1446c269f196SRoland McGrath 1447c269f196SRoland McGrath out_put_task_struct: 1448c269f196SRoland McGrath put_task_struct(child); 1449c269f196SRoland McGrath out: 1450c269f196SRoland McGrath return ret; 1451c269f196SRoland McGrath } 145296b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1453