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> 341da177e4SLinus Torvalds 35201766a2SElvira Khabirova #include <asm/syscall.h> /* for syscall_get_* */ 36201766a2SElvira Khabirova 3784d77d3fSEric W. Biederman /* 3884d77d3fSEric W. Biederman * Access another process' address space via ptrace. 3984d77d3fSEric W. Biederman * Source/target buffer must be kernel space, 4084d77d3fSEric W. Biederman * Do not walk the page table directly, use get_user_pages 4184d77d3fSEric W. Biederman */ 4284d77d3fSEric W. Biederman int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, 4384d77d3fSEric W. Biederman void *buf, int len, unsigned int gup_flags) 4484d77d3fSEric W. Biederman { 4584d77d3fSEric W. Biederman struct mm_struct *mm; 4684d77d3fSEric W. Biederman int ret; 4784d77d3fSEric W. Biederman 4884d77d3fSEric W. Biederman mm = get_task_mm(tsk); 4984d77d3fSEric W. Biederman if (!mm) 5084d77d3fSEric W. Biederman return 0; 5184d77d3fSEric W. Biederman 5284d77d3fSEric W. Biederman if (!tsk->ptrace || 5384d77d3fSEric W. Biederman (current != tsk->parent) || 5484d77d3fSEric W. Biederman ((get_dumpable(mm) != SUID_DUMP_USER) && 5584d77d3fSEric W. Biederman !ptracer_capable(tsk, mm->user_ns))) { 5684d77d3fSEric W. Biederman mmput(mm); 5784d77d3fSEric W. Biederman return 0; 5884d77d3fSEric W. Biederman } 5984d77d3fSEric W. Biederman 60d3f5ffcaSJohn Hubbard ret = __access_remote_vm(mm, addr, buf, len, gup_flags); 6184d77d3fSEric W. Biederman mmput(mm); 6284d77d3fSEric W. Biederman 6384d77d3fSEric W. Biederman return ret; 6484d77d3fSEric W. Biederman } 6584d77d3fSEric W. Biederman 66bf53de90SMarkus Metzger 67c70d9d80SEric W. Biederman void __ptrace_link(struct task_struct *child, struct task_struct *new_parent, 68c70d9d80SEric W. Biederman const struct cred *ptracer_cred) 69c70d9d80SEric W. Biederman { 70c70d9d80SEric W. Biederman BUG_ON(!list_empty(&child->ptrace_entry)); 71c70d9d80SEric W. Biederman list_add(&child->ptrace_entry, &new_parent->ptraced); 72c70d9d80SEric W. Biederman child->parent = new_parent; 73c70d9d80SEric W. Biederman child->ptracer_cred = get_cred(ptracer_cred); 74c70d9d80SEric W. Biederman } 75c70d9d80SEric W. Biederman 76bf53de90SMarkus Metzger /* 771da177e4SLinus Torvalds * ptrace a task: make the debugger its new parent and 781da177e4SLinus Torvalds * move it to the ptrace list. 791da177e4SLinus Torvalds * 801da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 811da177e4SLinus Torvalds */ 82c70d9d80SEric W. Biederman static void ptrace_link(struct task_struct *child, struct task_struct *new_parent) 831da177e4SLinus Torvalds { 846994eefbSJann Horn __ptrace_link(child, new_parent, current_cred()); 851da177e4SLinus Torvalds } 861da177e4SLinus Torvalds 87e3bd058fSTejun Heo /** 88e3bd058fSTejun Heo * __ptrace_unlink - unlink ptracee and restore its execution state 89e3bd058fSTejun Heo * @child: ptracee to be unlinked 901da177e4SLinus Torvalds * 910e9f0a4aSTejun Heo * Remove @child from the ptrace list, move it back to the original parent, 920e9f0a4aSTejun Heo * and restore the execution state so that it conforms to the group stop 930e9f0a4aSTejun Heo * state. 940e9f0a4aSTejun Heo * 950e9f0a4aSTejun Heo * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer 960e9f0a4aSTejun Heo * exiting. For PTRACE_DETACH, unless the ptracee has been killed between 970e9f0a4aSTejun Heo * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. 980e9f0a4aSTejun Heo * If the ptracer is exiting, the ptracee can be in any state. 990e9f0a4aSTejun Heo * 1000e9f0a4aSTejun Heo * After detach, the ptracee should be in a state which conforms to the 1010e9f0a4aSTejun Heo * group stop. If the group is stopped or in the process of stopping, the 1020e9f0a4aSTejun Heo * ptracee should be put into TASK_STOPPED; otherwise, it should be woken 1030e9f0a4aSTejun Heo * up from TASK_TRACED. 1040e9f0a4aSTejun Heo * 1050e9f0a4aSTejun Heo * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, 1060e9f0a4aSTejun Heo * it goes through TRACED -> RUNNING -> STOPPED transition which is similar 1070e9f0a4aSTejun Heo * to but in the opposite direction of what happens while attaching to a 1080e9f0a4aSTejun Heo * stopped task. However, in this direction, the intermediate RUNNING 1090e9f0a4aSTejun Heo * state is not hidden even from the current ptracer and if it immediately 1100e9f0a4aSTejun Heo * re-attaches and performs a WNOHANG wait(2), it may fail. 111e3bd058fSTejun Heo * 112e3bd058fSTejun Heo * CONTEXT: 113e3bd058fSTejun Heo * write_lock_irq(tasklist_lock) 1141da177e4SLinus Torvalds */ 11536c8b586SIngo Molnar void __ptrace_unlink(struct task_struct *child) 1161da177e4SLinus Torvalds { 11764b875f7SEric W. Biederman const struct cred *old_cred; 1185ecfbae0SOleg Nesterov BUG_ON(!child->ptrace); 1195ecfbae0SOleg Nesterov 12064c19ba2SGabriel Krisman Bertazi clear_task_syscall_work(child, SYSCALL_TRACE); 12164eb35f7SGabriel Krisman Bertazi #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) 12264eb35f7SGabriel Krisman Bertazi clear_task_syscall_work(child, SYSCALL_EMU); 12315532fd6SSudeep Holla #endif 1240a5bf409SAles Novak 1251da177e4SLinus Torvalds child->parent = child->real_parent; 126f470021aSRoland McGrath list_del_init(&child->ptrace_entry); 12764b875f7SEric W. Biederman old_cred = child->ptracer_cred; 12864b875f7SEric W. Biederman child->ptracer_cred = NULL; 12964b875f7SEric W. Biederman put_cred(old_cred); 1301da177e4SLinus Torvalds 1311da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 1321333ab03SOleg Nesterov child->ptrace = 0; 1331da177e4SLinus Torvalds /* 13473ddff2bSTejun Heo * Clear all pending traps and TRAPPING. TRAPPING should be 13573ddff2bSTejun Heo * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. 13673ddff2bSTejun Heo */ 13773ddff2bSTejun Heo task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); 13873ddff2bSTejun Heo task_clear_jobctl_trapping(child); 13973ddff2bSTejun Heo 14073ddff2bSTejun Heo /* 141a8f072c1STejun Heo * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and 1420e9f0a4aSTejun Heo * @child isn't dead. 1431da177e4SLinus Torvalds */ 1440e9f0a4aSTejun Heo if (!(child->flags & PF_EXITING) && 1450e9f0a4aSTejun Heo (child->signal->flags & SIGNAL_STOP_STOPPED || 1468a88951bSOleg Nesterov child->signal->group_stop_count)) { 147a8f072c1STejun Heo child->jobctl |= JOBCTL_STOP_PENDING; 1480e9f0a4aSTejun Heo 1490e9f0a4aSTejun Heo /* 1508a88951bSOleg Nesterov * This is only possible if this thread was cloned by the 1518a88951bSOleg Nesterov * traced task running in the stopped group, set the signal 1528a88951bSOleg Nesterov * for the future reports. 1538a88951bSOleg Nesterov * FIXME: we should change ptrace_init_task() to handle this 1548a88951bSOleg Nesterov * case. 1558a88951bSOleg Nesterov */ 1568a88951bSOleg Nesterov if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) 1578a88951bSOleg Nesterov child->jobctl |= SIGSTOP; 1588a88951bSOleg Nesterov } 1598a88951bSOleg Nesterov 1608a88951bSOleg Nesterov /* 1610e9f0a4aSTejun Heo * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick 1620e9f0a4aSTejun Heo * @child in the butt. Note that @resume should be used iff @child 1630e9f0a4aSTejun Heo * is in TASK_TRACED; otherwise, we might unduly disrupt 1640e9f0a4aSTejun Heo * TASK_KILLABLE sleeps. 1650e9f0a4aSTejun Heo */ 166a8f072c1STejun Heo if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) 167910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 1680e9f0a4aSTejun Heo 1691da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 1701da177e4SLinus Torvalds } 1711da177e4SLinus Torvalds 1729899d11fSOleg Nesterov /* Ensure that nothing can wake it up, even SIGKILL */ 1739899d11fSOleg Nesterov static bool ptrace_freeze_traced(struct task_struct *task) 1749899d11fSOleg Nesterov { 1759899d11fSOleg Nesterov bool ret = false; 1769899d11fSOleg Nesterov 1779899d11fSOleg Nesterov /* Lockless, nobody but us can set this flag */ 1789899d11fSOleg Nesterov if (task->jobctl & JOBCTL_LISTENING) 1799899d11fSOleg Nesterov return ret; 1809899d11fSOleg Nesterov 1819899d11fSOleg Nesterov spin_lock_irq(&task->sighand->siglock); 1829899d11fSOleg Nesterov if (task_is_traced(task) && !__fatal_signal_pending(task)) { 1839899d11fSOleg Nesterov task->state = __TASK_TRACED; 1849899d11fSOleg Nesterov ret = true; 1859899d11fSOleg Nesterov } 1869899d11fSOleg Nesterov spin_unlock_irq(&task->sighand->siglock); 1879899d11fSOleg Nesterov 1889899d11fSOleg Nesterov return ret; 1899899d11fSOleg Nesterov } 1909899d11fSOleg Nesterov 1919899d11fSOleg Nesterov static void ptrace_unfreeze_traced(struct task_struct *task) 1929899d11fSOleg Nesterov { 1939899d11fSOleg Nesterov if (task->state != __TASK_TRACED) 1949899d11fSOleg Nesterov return; 1959899d11fSOleg Nesterov 1969899d11fSOleg Nesterov WARN_ON(!task->ptrace || task->parent != current); 1979899d11fSOleg Nesterov 1985402e97aSbsegall@google.com /* 1995402e97aSbsegall@google.com * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely. 2005402e97aSbsegall@google.com * Recheck state under the lock to close this race. 2015402e97aSbsegall@google.com */ 2029899d11fSOleg Nesterov spin_lock_irq(&task->sighand->siglock); 2035402e97aSbsegall@google.com if (task->state == __TASK_TRACED) { 2049899d11fSOleg Nesterov if (__fatal_signal_pending(task)) 2059899d11fSOleg Nesterov wake_up_state(task, __TASK_TRACED); 2069899d11fSOleg Nesterov else 2079899d11fSOleg Nesterov task->state = TASK_TRACED; 2085402e97aSbsegall@google.com } 2099899d11fSOleg Nesterov spin_unlock_irq(&task->sighand->siglock); 2109899d11fSOleg Nesterov } 2119899d11fSOleg Nesterov 212755e276bSTejun Heo /** 213755e276bSTejun Heo * ptrace_check_attach - check whether ptracee is ready for ptrace operation 214755e276bSTejun Heo * @child: ptracee to check for 215755e276bSTejun Heo * @ignore_state: don't check whether @child is currently %TASK_TRACED 216755e276bSTejun Heo * 217755e276bSTejun Heo * Check whether @child is being ptraced by %current and ready for further 218755e276bSTejun Heo * ptrace operations. If @ignore_state is %false, @child also should be in 219755e276bSTejun Heo * %TASK_TRACED state and on return the child is guaranteed to be traced 220755e276bSTejun Heo * and not executing. If @ignore_state is %true, @child can be in any 221755e276bSTejun Heo * state. 222755e276bSTejun Heo * 223755e276bSTejun Heo * CONTEXT: 224755e276bSTejun Heo * Grabs and releases tasklist_lock and @child->sighand->siglock. 225755e276bSTejun Heo * 226755e276bSTejun Heo * RETURNS: 227755e276bSTejun Heo * 0 on success, -ESRCH if %child is not ready. 2281da177e4SLinus Torvalds */ 229edea0d03SOleg Nesterov static int ptrace_check_attach(struct task_struct *child, bool ignore_state) 2301da177e4SLinus Torvalds { 2311da177e4SLinus Torvalds int ret = -ESRCH; 2321da177e4SLinus Torvalds 2331da177e4SLinus Torvalds /* 2341da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 2351da177e4SLinus Torvalds * possible race where someone else was tracing our child and 2361da177e4SLinus Torvalds * detached between these two checks. After this locked check, 2371da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 2381da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 2391da177e4SLinus Torvalds */ 2401da177e4SLinus Torvalds read_lock(&tasklist_lock); 2419899d11fSOleg Nesterov if (child->ptrace && child->parent == current) { 2429899d11fSOleg Nesterov WARN_ON(child->state == __TASK_TRACED); 243c0c0b649SOleg Nesterov /* 244c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 245c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 246c0c0b649SOleg Nesterov */ 2479899d11fSOleg Nesterov if (ignore_state || ptrace_freeze_traced(child)) 248321fb561SOleg Nesterov ret = 0; 2491da177e4SLinus Torvalds } 2501da177e4SLinus Torvalds read_unlock(&tasklist_lock); 2511da177e4SLinus Torvalds 2529899d11fSOleg Nesterov if (!ret && !ignore_state) { 2539899d11fSOleg Nesterov if (!wait_task_inactive(child, __TASK_TRACED)) { 2549899d11fSOleg Nesterov /* 2559899d11fSOleg Nesterov * This can only happen if may_ptrace_stop() fails and 2569899d11fSOleg Nesterov * ptrace_stop() changes ->state back to TASK_RUNNING, 2579899d11fSOleg Nesterov * so we should not worry about leaking __TASK_TRACED. 2589899d11fSOleg Nesterov */ 2599899d11fSOleg Nesterov WARN_ON(child->state == __TASK_TRACED); 2609899d11fSOleg Nesterov ret = -ESRCH; 2619899d11fSOleg Nesterov } 2629899d11fSOleg Nesterov } 2631da177e4SLinus Torvalds 2641da177e4SLinus Torvalds return ret; 2651da177e4SLinus Torvalds } 2661da177e4SLinus Torvalds 267cf237052SMickaël Salaün static bool ptrace_has_cap(struct user_namespace *ns, unsigned int mode) 26869f594a3SEric Paris { 26969f594a3SEric Paris if (mode & PTRACE_MODE_NOAUDIT) 270cf237052SMickaël Salaün return ns_capable_noaudit(ns, CAP_SYS_PTRACE); 271cf237052SMickaël Salaün return ns_capable(ns, CAP_SYS_PTRACE); 27269f594a3SEric Paris } 27369f594a3SEric Paris 2749f99798fSTetsuo Handa /* Returns 0 on success, -errno on denial. */ 2759f99798fSTetsuo Handa static int __ptrace_may_access(struct task_struct *task, unsigned int mode) 276ab8d11beSMiklos Szeredi { 277c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 278bfedb589SEric W. Biederman struct mm_struct *mm; 279caaee623SJann Horn kuid_t caller_uid; 280caaee623SJann Horn kgid_t caller_gid; 281caaee623SJann Horn 282caaee623SJann Horn if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { 283caaee623SJann Horn WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); 284caaee623SJann Horn return -EPERM; 285caaee623SJann Horn } 286b6dff3ecSDavid Howells 287df26c40eSEric W. Biederman /* May we inspect the given task? 288df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 289df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 290df26c40eSEric W. Biederman * 291df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 292df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 293df26c40eSEric W. Biederman * or halting the specified task is impossible. 294df26c40eSEric W. Biederman */ 295caaee623SJann Horn 296df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 29773af963fSMark Grondona if (same_thread_group(task, current)) 298df26c40eSEric W. Biederman return 0; 299c69e8d9cSDavid Howells rcu_read_lock(); 300caaee623SJann Horn if (mode & PTRACE_MODE_FSCREDS) { 301caaee623SJann Horn caller_uid = cred->fsuid; 302caaee623SJann Horn caller_gid = cred->fsgid; 303caaee623SJann Horn } else { 304caaee623SJann Horn /* 305caaee623SJann Horn * Using the euid would make more sense here, but something 306caaee623SJann Horn * in userland might rely on the old behavior, and this 307caaee623SJann Horn * shouldn't be a security problem since 308caaee623SJann Horn * PTRACE_MODE_REALCREDS implies that the caller explicitly 309caaee623SJann Horn * used a syscall that requests access to another process 310caaee623SJann Horn * (and not a filesystem syscall to procfs). 311caaee623SJann Horn */ 312caaee623SJann Horn caller_uid = cred->uid; 313caaee623SJann Horn caller_gid = cred->gid; 314caaee623SJann Horn } 315c69e8d9cSDavid Howells tcred = __task_cred(task); 316caaee623SJann Horn if (uid_eq(caller_uid, tcred->euid) && 317caaee623SJann Horn uid_eq(caller_uid, tcred->suid) && 318caaee623SJann Horn uid_eq(caller_uid, tcred->uid) && 319caaee623SJann Horn gid_eq(caller_gid, tcred->egid) && 320caaee623SJann Horn gid_eq(caller_gid, tcred->sgid) && 321caaee623SJann Horn gid_eq(caller_gid, tcred->gid)) 3228409cca7SSerge E. Hallyn goto ok; 323cf237052SMickaël Salaün if (ptrace_has_cap(tcred->user_ns, mode)) 3248409cca7SSerge E. Hallyn goto ok; 325c69e8d9cSDavid Howells rcu_read_unlock(); 326ab8d11beSMiklos Szeredi return -EPERM; 3278409cca7SSerge E. Hallyn ok: 328c69e8d9cSDavid Howells rcu_read_unlock(); 329f6581f5bSJann Horn /* 330f6581f5bSJann Horn * If a task drops privileges and becomes nondumpable (through a syscall 331f6581f5bSJann Horn * like setresuid()) while we are trying to access it, we must ensure 332f6581f5bSJann Horn * that the dumpability is read after the credentials; otherwise, 333f6581f5bSJann Horn * we may be able to attach to a task that we shouldn't be able to 334f6581f5bSJann Horn * attach to (as if the task had dropped privileges without becoming 335f6581f5bSJann Horn * nondumpable). 336f6581f5bSJann Horn * Pairs with a write barrier in commit_creds(). 337f6581f5bSJann Horn */ 338f6581f5bSJann Horn smp_rmb(); 339bfedb589SEric W. Biederman mm = task->mm; 340bfedb589SEric W. Biederman if (mm && 341bfedb589SEric W. Biederman ((get_dumpable(mm) != SUID_DUMP_USER) && 342cf237052SMickaël Salaün !ptrace_has_cap(mm->user_ns, mode))) 343ab8d11beSMiklos Szeredi return -EPERM; 344ab8d11beSMiklos Szeredi 3459e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 346ab8d11beSMiklos Szeredi } 347ab8d11beSMiklos Szeredi 348006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 349ab8d11beSMiklos Szeredi { 350ab8d11beSMiklos Szeredi int err; 351ab8d11beSMiklos Szeredi task_lock(task); 352006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 353ab8d11beSMiklos Szeredi task_unlock(task); 3543a709703SRoland McGrath return !err; 355ab8d11beSMiklos Szeredi } 356ab8d11beSMiklos Szeredi 3573544d72aSTejun Heo static int ptrace_attach(struct task_struct *task, long request, 358aa9147c9SDenys Vlasenko unsigned long addr, 3593544d72aSTejun Heo unsigned long flags) 3601da177e4SLinus Torvalds { 3613544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 3621da177e4SLinus Torvalds int retval; 363f5b40e36SLinus Torvalds 3643544d72aSTejun Heo retval = -EIO; 365aa9147c9SDenys Vlasenko if (seize) { 366aa9147c9SDenys Vlasenko if (addr != 0) 3673544d72aSTejun Heo goto out; 368aa9147c9SDenys Vlasenko if (flags & ~(unsigned long)PTRACE_O_MASK) 369aa9147c9SDenys Vlasenko goto out; 370aa9147c9SDenys Vlasenko flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); 371aa9147c9SDenys Vlasenko } else { 372aa9147c9SDenys Vlasenko flags = PT_PTRACED; 373aa9147c9SDenys Vlasenko } 3743544d72aSTejun Heo 375a5cb013dSAl Viro audit_ptrace(task); 376a5cb013dSAl Viro 3771da177e4SLinus Torvalds retval = -EPERM; 378*e8b33b8cSJens Axboe if (unlikely(task->flags & PF_KTHREAD)) 379b79b7ba9SOleg Nesterov goto out; 380bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 381f5b40e36SLinus Torvalds goto out; 382f5b40e36SLinus Torvalds 383f2f0b00aSOleg Nesterov /* 384f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 38586b6c1f3SDenys Vlasenko * SUID, SGID and LSM creds get determined differently 3865e751e99SDavid Howells * under ptrace. 387d84f4f99SDavid Howells */ 388793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 3899b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 390d84f4f99SDavid Howells goto out; 3914b105cbbSOleg Nesterov 392f5b40e36SLinus Torvalds task_lock(task); 393caaee623SJann Horn retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); 3944b105cbbSOleg Nesterov task_unlock(task); 3951da177e4SLinus Torvalds if (retval) 3964b105cbbSOleg Nesterov goto unlock_creds; 3971da177e4SLinus Torvalds 3984b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 399b79b7ba9SOleg Nesterov retval = -EPERM; 400b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 4014b105cbbSOleg Nesterov goto unlock_tasklist; 402f2f0b00aSOleg Nesterov if (task->ptrace) 4034b105cbbSOleg Nesterov goto unlock_tasklist; 404b79b7ba9SOleg Nesterov 4053544d72aSTejun Heo if (seize) 406aa9147c9SDenys Vlasenko flags |= PT_SEIZED; 407aa9147c9SDenys Vlasenko task->ptrace = flags; 4081da177e4SLinus Torvalds 409c70d9d80SEric W. Biederman ptrace_link(task, current); 4103544d72aSTejun Heo 4113544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 4123544d72aSTejun Heo if (!seize) 413079b22dcSEric W. Biederman send_sig_info(SIGSTOP, SEND_SIG_PRIV, task); 414b79b7ba9SOleg Nesterov 415d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 416d79fdd6dSTejun Heo 417d79fdd6dSTejun Heo /* 41873ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 419d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 420d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 421d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 422d79fdd6dSTejun Heo * for the transition to complete before returning from this 423d79fdd6dSTejun Heo * function. 424d79fdd6dSTejun Heo * 425d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 426d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 427d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 428d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 429d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 430d79fdd6dSTejun Heo * 431d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 432d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 433d79fdd6dSTejun Heo */ 4347dd3db54STejun Heo if (task_is_stopped(task) && 43573ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 436910ffdb1SOleg Nesterov signal_wake_up_state(task, __TASK_STOPPED); 437d79fdd6dSTejun Heo 438d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 439d79fdd6dSTejun Heo 440b79b7ba9SOleg Nesterov retval = 0; 4414b105cbbSOleg Nesterov unlock_tasklist: 4424b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 4434b105cbbSOleg Nesterov unlock_creds: 4449b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 445f5b40e36SLinus Torvalds out: 446f701e5b7SVladimir Zapolskiy if (!retval) { 4477c3b00e0SOleg Nesterov /* 4487c3b00e0SOleg Nesterov * We do not bother to change retval or clear JOBCTL_TRAPPING 4497c3b00e0SOleg Nesterov * if wait_on_bit() was interrupted by SIGKILL. The tracer will 4507c3b00e0SOleg Nesterov * not return to user-mode, it will exit and clear this bit in 4517c3b00e0SOleg Nesterov * __ptrace_unlink() if it wasn't already cleared by the tracee; 4527c3b00e0SOleg Nesterov * and until then nobody can ptrace this task. 4537c3b00e0SOleg Nesterov */ 4547c3b00e0SOleg Nesterov wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); 455f701e5b7SVladimir Zapolskiy proc_ptrace_connector(task, PTRACE_ATTACH); 456f701e5b7SVladimir Zapolskiy } 457f701e5b7SVladimir Zapolskiy 4581da177e4SLinus Torvalds return retval; 4591da177e4SLinus Torvalds } 4601da177e4SLinus Torvalds 461f2f0b00aSOleg Nesterov /** 462f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 463f2f0b00aSOleg Nesterov * 464f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 465f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 466f2f0b00aSOleg Nesterov */ 467e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 468f2f0b00aSOleg Nesterov { 469f2f0b00aSOleg Nesterov int ret = -EPERM; 470f2f0b00aSOleg Nesterov 4714b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 4724b105cbbSOleg Nesterov /* Are we already being traced? */ 473f2f0b00aSOleg Nesterov if (!current->ptrace) { 474f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 475f2f0b00aSOleg Nesterov /* 476f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 477f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 478f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 479f2f0b00aSOleg Nesterov */ 480f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 481f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 482c70d9d80SEric W. Biederman ptrace_link(current, current->real_parent); 483f2f0b00aSOleg Nesterov } 484f2f0b00aSOleg Nesterov } 4854b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 4864b105cbbSOleg Nesterov 487f2f0b00aSOleg Nesterov return ret; 488f2f0b00aSOleg Nesterov } 489f2f0b00aSOleg Nesterov 49039c626aeSOleg Nesterov /* 49139c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 49239c626aeSOleg Nesterov */ 49339c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 49439c626aeSOleg Nesterov { 49539c626aeSOleg Nesterov int ret; 49639c626aeSOleg Nesterov spin_lock(&sigh->siglock); 49739c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 49839c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 49939c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 50039c626aeSOleg Nesterov return ret; 50139c626aeSOleg Nesterov } 50239c626aeSOleg Nesterov 50339c626aeSOleg Nesterov /* 50439c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 50539c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 50639c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 50739c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 50839c626aeSOleg Nesterov * 50939c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 51039c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 51139c626aeSOleg Nesterov * If it should reap itself, return true. 51239c626aeSOleg Nesterov * 513a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 514a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 515a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 516a7f0765eSOleg Nesterov * do_wait(). 51739c626aeSOleg Nesterov */ 51839c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 51939c626aeSOleg Nesterov { 5209843a1e9SOleg Nesterov bool dead; 5219843a1e9SOleg Nesterov 52239c626aeSOleg Nesterov __ptrace_unlink(p); 52339c626aeSOleg Nesterov 5249843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 5259843a1e9SOleg Nesterov return false; 5269843a1e9SOleg Nesterov 5279843a1e9SOleg Nesterov dead = !thread_group_leader(p); 5289843a1e9SOleg Nesterov 5299843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 53039c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 5319843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 532a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 533a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 5349843a1e9SOleg Nesterov dead = true; 53539c626aeSOleg Nesterov } 536a7f0765eSOleg Nesterov } 53739c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 5389843a1e9SOleg Nesterov if (dead) 53939c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 5409843a1e9SOleg Nesterov return dead; 54139c626aeSOleg Nesterov } 54239c626aeSOleg Nesterov 543e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 5441da177e4SLinus Torvalds { 5457ed20e1aSJesper Juhl if (!valid_signal(data)) 5461da177e4SLinus Torvalds return -EIO; 5471da177e4SLinus Torvalds 5481da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 5491da177e4SLinus Torvalds ptrace_disable(child); 5501da177e4SLinus Torvalds 55195c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 55239c626aeSOleg Nesterov /* 55364a4096cSOleg Nesterov * We rely on ptrace_freeze_traced(). It can't be killed and 55464a4096cSOleg Nesterov * untraced by another thread, it can't be a zombie. 55539c626aeSOleg Nesterov */ 55664a4096cSOleg Nesterov WARN_ON(!child->ptrace || child->exit_state); 55764a4096cSOleg Nesterov /* 55864a4096cSOleg Nesterov * tasklist_lock avoids the race with wait_task_stopped(), see 55964a4096cSOleg Nesterov * the comment in ptrace_resume(). 56064a4096cSOleg Nesterov */ 56195c3eb76SOleg Nesterov child->exit_code = data; 56264a4096cSOleg Nesterov __ptrace_detach(current, child); 5631da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 5641da177e4SLinus Torvalds 565f701e5b7SVladimir Zapolskiy proc_ptrace_connector(child, PTRACE_DETACH); 5664576145cSOleg Nesterov 5671da177e4SLinus Torvalds return 0; 5681da177e4SLinus Torvalds } 5691da177e4SLinus Torvalds 57039c626aeSOleg Nesterov /* 571c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 5727c8bd232SOleg Nesterov * for writing. 57339c626aeSOleg Nesterov */ 5747c8bd232SOleg Nesterov void exit_ptrace(struct task_struct *tracer, struct list_head *dead) 57539c626aeSOleg Nesterov { 57639c626aeSOleg Nesterov struct task_struct *p, *n; 577c7e49c14SOleg Nesterov 57839c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 579992fb6e1SOleg Nesterov if (unlikely(p->ptrace & PT_EXITKILL)) 580079b22dcSEric W. Biederman send_sig_info(SIGKILL, SEND_SIG_PRIV, p); 581992fb6e1SOleg Nesterov 58239c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 5837c8bd232SOleg Nesterov list_add(&p->ptrace_entry, dead); 58439c626aeSOleg Nesterov } 58539c626aeSOleg Nesterov } 58639c626aeSOleg Nesterov 5871da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 5881da177e4SLinus Torvalds { 5891da177e4SLinus Torvalds int copied = 0; 5901da177e4SLinus Torvalds 5911da177e4SLinus Torvalds while (len > 0) { 5921da177e4SLinus Torvalds char buf[128]; 5931da177e4SLinus Torvalds int this_len, retval; 5941da177e4SLinus Torvalds 5951da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 59684d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE); 59784d77d3fSEric W. Biederman 5981da177e4SLinus Torvalds if (!retval) { 5991da177e4SLinus Torvalds if (copied) 6001da177e4SLinus Torvalds break; 6011da177e4SLinus Torvalds return -EIO; 6021da177e4SLinus Torvalds } 6031da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 6041da177e4SLinus Torvalds return -EFAULT; 6051da177e4SLinus Torvalds copied += retval; 6061da177e4SLinus Torvalds src += retval; 6071da177e4SLinus Torvalds dst += retval; 6081da177e4SLinus Torvalds len -= retval; 6091da177e4SLinus Torvalds } 6101da177e4SLinus Torvalds return copied; 6111da177e4SLinus Torvalds } 6121da177e4SLinus Torvalds 6131da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 6141da177e4SLinus Torvalds { 6151da177e4SLinus Torvalds int copied = 0; 6161da177e4SLinus Torvalds 6171da177e4SLinus Torvalds while (len > 0) { 6181da177e4SLinus Torvalds char buf[128]; 6191da177e4SLinus Torvalds int this_len, retval; 6201da177e4SLinus Torvalds 6211da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 6221da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 6231da177e4SLinus Torvalds return -EFAULT; 62484d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, dst, buf, this_len, 625f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 6261da177e4SLinus Torvalds if (!retval) { 6271da177e4SLinus Torvalds if (copied) 6281da177e4SLinus Torvalds break; 6291da177e4SLinus Torvalds return -EIO; 6301da177e4SLinus Torvalds } 6311da177e4SLinus Torvalds copied += retval; 6321da177e4SLinus Torvalds src += retval; 6331da177e4SLinus Torvalds dst += retval; 6341da177e4SLinus Torvalds len -= retval; 6351da177e4SLinus Torvalds } 6361da177e4SLinus Torvalds return copied; 6371da177e4SLinus Torvalds } 6381da177e4SLinus Torvalds 6394abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 6401da177e4SLinus Torvalds { 64186b6c1f3SDenys Vlasenko unsigned flags; 64286b6c1f3SDenys Vlasenko 6438c5cf9e5SDenys Vlasenko if (data & ~(unsigned long)PTRACE_O_MASK) 6448c5cf9e5SDenys Vlasenko return -EINVAL; 6458c5cf9e5SDenys Vlasenko 64613c4a901STycho Andersen if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { 64797f2645fSMasahiro Yamada if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || 64897f2645fSMasahiro Yamada !IS_ENABLED(CONFIG_SECCOMP)) 64913c4a901STycho Andersen return -EINVAL; 65013c4a901STycho Andersen 65113c4a901STycho Andersen if (!capable(CAP_SYS_ADMIN)) 65213c4a901STycho Andersen return -EPERM; 65313c4a901STycho Andersen 65413c4a901STycho Andersen if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || 65513c4a901STycho Andersen current->ptrace & PT_SUSPEND_SECCOMP) 65613c4a901STycho Andersen return -EPERM; 65713c4a901STycho Andersen } 65813c4a901STycho Andersen 65986b6c1f3SDenys Vlasenko /* Avoid intermediate state when all opts are cleared */ 66086b6c1f3SDenys Vlasenko flags = child->ptrace; 66186b6c1f3SDenys Vlasenko flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); 66286b6c1f3SDenys Vlasenko flags |= (data << PT_OPT_FLAG_SHIFT); 66386b6c1f3SDenys Vlasenko child->ptrace = flags; 6641da177e4SLinus Torvalds 6658c5cf9e5SDenys Vlasenko return 0; 6661da177e4SLinus Torvalds } 6671da177e4SLinus Torvalds 668ae7795bcSEric W. Biederman static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info) 6691da177e4SLinus Torvalds { 670e4961254SOleg Nesterov unsigned long flags; 6711da177e4SLinus Torvalds int error = -ESRCH; 6721da177e4SLinus Torvalds 673e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 6741da177e4SLinus Torvalds error = -EINVAL; 6751da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 6760752d7bfSEric W. Biederman copy_siginfo(info, child->last_siginfo); 6771da177e4SLinus Torvalds error = 0; 6781da177e4SLinus Torvalds } 679e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 6801da177e4SLinus Torvalds } 6811da177e4SLinus Torvalds return error; 6821da177e4SLinus Torvalds } 6831da177e4SLinus Torvalds 684ae7795bcSEric W. Biederman static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info) 6851da177e4SLinus Torvalds { 686e4961254SOleg Nesterov unsigned long flags; 6871da177e4SLinus Torvalds int error = -ESRCH; 6881da177e4SLinus Torvalds 689e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 6901da177e4SLinus Torvalds error = -EINVAL; 6911da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 6920752d7bfSEric W. Biederman copy_siginfo(child->last_siginfo, info); 6931da177e4SLinus Torvalds error = 0; 6941da177e4SLinus Torvalds } 695e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 6961da177e4SLinus Torvalds } 6971da177e4SLinus Torvalds return error; 6981da177e4SLinus Torvalds } 6991da177e4SLinus Torvalds 70084c751bdSAndrey Vagin static int ptrace_peek_siginfo(struct task_struct *child, 70184c751bdSAndrey Vagin unsigned long addr, 70284c751bdSAndrey Vagin unsigned long data) 70384c751bdSAndrey Vagin { 70484c751bdSAndrey Vagin struct ptrace_peeksiginfo_args arg; 70584c751bdSAndrey Vagin struct sigpending *pending; 70684c751bdSAndrey Vagin struct sigqueue *q; 70784c751bdSAndrey Vagin int ret, i; 70884c751bdSAndrey Vagin 70984c751bdSAndrey Vagin ret = copy_from_user(&arg, (void __user *) addr, 71084c751bdSAndrey Vagin sizeof(struct ptrace_peeksiginfo_args)); 71184c751bdSAndrey Vagin if (ret) 71284c751bdSAndrey Vagin return -EFAULT; 71384c751bdSAndrey Vagin 71484c751bdSAndrey Vagin if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) 71584c751bdSAndrey Vagin return -EINVAL; /* unknown flags */ 71684c751bdSAndrey Vagin 71784c751bdSAndrey Vagin if (arg.nr < 0) 71884c751bdSAndrey Vagin return -EINVAL; 71984c751bdSAndrey Vagin 720f6e2aa91SEric W. Biederman /* Ensure arg.off fits in an unsigned long */ 721f6e2aa91SEric W. Biederman if (arg.off > ULONG_MAX) 722f6e2aa91SEric W. Biederman return 0; 723f6e2aa91SEric W. Biederman 72484c751bdSAndrey Vagin if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) 72584c751bdSAndrey Vagin pending = &child->signal->shared_pending; 72684c751bdSAndrey Vagin else 72784c751bdSAndrey Vagin pending = &child->pending; 72884c751bdSAndrey Vagin 72984c751bdSAndrey Vagin for (i = 0; i < arg.nr; ) { 730ae7795bcSEric W. Biederman kernel_siginfo_t info; 731f6e2aa91SEric W. Biederman unsigned long off = arg.off + i; 732f6e2aa91SEric W. Biederman bool found = false; 73384c751bdSAndrey Vagin 73484c751bdSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 73584c751bdSAndrey Vagin list_for_each_entry(q, &pending->list, list) { 73684c751bdSAndrey Vagin if (!off--) { 737f6e2aa91SEric W. Biederman found = true; 73884c751bdSAndrey Vagin copy_siginfo(&info, &q->info); 73984c751bdSAndrey Vagin break; 74084c751bdSAndrey Vagin } 74184c751bdSAndrey Vagin } 74284c751bdSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 74384c751bdSAndrey Vagin 744f6e2aa91SEric W. Biederman if (!found) /* beyond the end of the list */ 74584c751bdSAndrey Vagin break; 74684c751bdSAndrey Vagin 74784c751bdSAndrey Vagin #ifdef CONFIG_COMPAT 7485c465217SAndy Lutomirski if (unlikely(in_compat_syscall())) { 74984c751bdSAndrey Vagin compat_siginfo_t __user *uinfo = compat_ptr(data); 75084c751bdSAndrey Vagin 751cc731525SEric W. Biederman if (copy_siginfo_to_user32(uinfo, &info)) { 752706b23bdSMathieu Desnoyers ret = -EFAULT; 753706b23bdSMathieu Desnoyers break; 754706b23bdSMathieu Desnoyers } 755706b23bdSMathieu Desnoyers 75684c751bdSAndrey Vagin } else 75784c751bdSAndrey Vagin #endif 75884c751bdSAndrey Vagin { 75984c751bdSAndrey Vagin siginfo_t __user *uinfo = (siginfo_t __user *) data; 76084c751bdSAndrey Vagin 761cc731525SEric W. Biederman if (copy_siginfo_to_user(uinfo, &info)) { 76284c751bdSAndrey Vagin ret = -EFAULT; 76384c751bdSAndrey Vagin break; 76484c751bdSAndrey Vagin } 765706b23bdSMathieu Desnoyers } 76684c751bdSAndrey Vagin 76784c751bdSAndrey Vagin data += sizeof(siginfo_t); 76884c751bdSAndrey Vagin i++; 76984c751bdSAndrey Vagin 77084c751bdSAndrey Vagin if (signal_pending(current)) 77184c751bdSAndrey Vagin break; 77284c751bdSAndrey Vagin 77384c751bdSAndrey Vagin cond_resched(); 77484c751bdSAndrey Vagin } 77584c751bdSAndrey Vagin 77684c751bdSAndrey Vagin if (i > 0) 77784c751bdSAndrey Vagin return i; 77884c751bdSAndrey Vagin 77984c751bdSAndrey Vagin return ret; 78084c751bdSAndrey Vagin } 78136df29d7SRoland McGrath 78236df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 78336df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 78436df29d7SRoland McGrath #else 78536df29d7SRoland McGrath #define is_singlestep(request) 0 78636df29d7SRoland McGrath #endif 78736df29d7SRoland McGrath 7885b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 7895b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 7905b88abbfSRoland McGrath #else 7915b88abbfSRoland McGrath #define is_singleblock(request) 0 7925b88abbfSRoland McGrath #endif 7935b88abbfSRoland McGrath 79436df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 79536df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 79636df29d7SRoland McGrath #else 79736df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 79836df29d7SRoland McGrath #endif 79936df29d7SRoland McGrath 8004abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 8014abf9869SNamhyung Kim unsigned long data) 80236df29d7SRoland McGrath { 803b72c1869SOleg Nesterov bool need_siglock; 804b72c1869SOleg Nesterov 80536df29d7SRoland McGrath if (!valid_signal(data)) 80636df29d7SRoland McGrath return -EIO; 80736df29d7SRoland McGrath 80836df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 80964c19ba2SGabriel Krisman Bertazi set_task_syscall_work(child, SYSCALL_TRACE); 81036df29d7SRoland McGrath else 81164c19ba2SGabriel Krisman Bertazi clear_task_syscall_work(child, SYSCALL_TRACE); 81236df29d7SRoland McGrath 81364eb35f7SGabriel Krisman Bertazi #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU) 81436df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 81564eb35f7SGabriel Krisman Bertazi set_task_syscall_work(child, SYSCALL_EMU); 81636df29d7SRoland McGrath else 81764eb35f7SGabriel Krisman Bertazi clear_task_syscall_work(child, SYSCALL_EMU); 81836df29d7SRoland McGrath #endif 81936df29d7SRoland McGrath 8205b88abbfSRoland McGrath if (is_singleblock(request)) { 8215b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 8225b88abbfSRoland McGrath return -EIO; 8235b88abbfSRoland McGrath user_enable_block_step(child); 8245b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 82536df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 82636df29d7SRoland McGrath return -EIO; 82736df29d7SRoland McGrath user_enable_single_step(child); 8283a709703SRoland McGrath } else { 82936df29d7SRoland McGrath user_disable_single_step(child); 8303a709703SRoland McGrath } 83136df29d7SRoland McGrath 832b72c1869SOleg Nesterov /* 833b72c1869SOleg Nesterov * Change ->exit_code and ->state under siglock to avoid the race 834b72c1869SOleg Nesterov * with wait_task_stopped() in between; a non-zero ->exit_code will 835b72c1869SOleg Nesterov * wrongly look like another report from tracee. 836b72c1869SOleg Nesterov * 837b72c1869SOleg Nesterov * Note that we need siglock even if ->exit_code == data and/or this 838b72c1869SOleg Nesterov * status was not reported yet, the new status must not be cleared by 839b72c1869SOleg Nesterov * wait_task_stopped() after resume. 840b72c1869SOleg Nesterov * 841b72c1869SOleg Nesterov * If data == 0 we do not care if wait_task_stopped() reports the old 842b72c1869SOleg Nesterov * status and clears the code too; this can't race with the tracee, it 843b72c1869SOleg Nesterov * takes siglock after resume. 844b72c1869SOleg Nesterov */ 845b72c1869SOleg Nesterov need_siglock = data && !thread_group_empty(current); 846b72c1869SOleg Nesterov if (need_siglock) 847b72c1869SOleg Nesterov spin_lock_irq(&child->sighand->siglock); 84836df29d7SRoland McGrath child->exit_code = data; 8490666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 850b72c1869SOleg Nesterov if (need_siglock) 851b72c1869SOleg Nesterov spin_unlock_irq(&child->sighand->siglock); 85236df29d7SRoland McGrath 85336df29d7SRoland McGrath return 0; 85436df29d7SRoland McGrath } 85536df29d7SRoland McGrath 8562225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8572225a122SSuresh Siddha 8582225a122SSuresh Siddha static const struct user_regset * 8592225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 8602225a122SSuresh Siddha { 8612225a122SSuresh Siddha const struct user_regset *regset; 8622225a122SSuresh Siddha int n; 8632225a122SSuresh Siddha 8642225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 8652225a122SSuresh Siddha regset = view->regsets + n; 8662225a122SSuresh Siddha if (regset->core_note_type == type) 8672225a122SSuresh Siddha return regset; 8682225a122SSuresh Siddha } 8692225a122SSuresh Siddha 8702225a122SSuresh Siddha return NULL; 8712225a122SSuresh Siddha } 8722225a122SSuresh Siddha 8732225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 8742225a122SSuresh Siddha struct iovec *kiov) 8752225a122SSuresh Siddha { 8762225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 8772225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 8782225a122SSuresh Siddha int regset_no; 8792225a122SSuresh Siddha 8802225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 881c6a0dd7eSSuresh Siddha return -EINVAL; 8822225a122SSuresh Siddha 8832225a122SSuresh Siddha regset_no = regset - view->regsets; 8842225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 8852225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 8862225a122SSuresh Siddha 8872225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 8882225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 8892225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 8902225a122SSuresh Siddha else 8912225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 8922225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 8932225a122SSuresh Siddha } 8942225a122SSuresh Siddha 895e8440c14SJosh Stone /* 896e8440c14SJosh Stone * This is declared in linux/regset.h and defined in machine-dependent 897e8440c14SJosh Stone * code. We put the export here, near the primary machine-neutral use, 898e8440c14SJosh Stone * to ensure no machine forgets it. 899e8440c14SJosh Stone */ 900e8440c14SJosh Stone EXPORT_SYMBOL_GPL(task_user_regset_view); 901201766a2SElvira Khabirova 902201766a2SElvira Khabirova static unsigned long 903201766a2SElvira Khabirova ptrace_get_syscall_info_entry(struct task_struct *child, struct pt_regs *regs, 904201766a2SElvira Khabirova struct ptrace_syscall_info *info) 905201766a2SElvira Khabirova { 906201766a2SElvira Khabirova unsigned long args[ARRAY_SIZE(info->entry.args)]; 907201766a2SElvira Khabirova int i; 908201766a2SElvira Khabirova 909201766a2SElvira Khabirova info->op = PTRACE_SYSCALL_INFO_ENTRY; 910201766a2SElvira Khabirova info->entry.nr = syscall_get_nr(child, regs); 911201766a2SElvira Khabirova syscall_get_arguments(child, regs, args); 912201766a2SElvira Khabirova for (i = 0; i < ARRAY_SIZE(args); i++) 913201766a2SElvira Khabirova info->entry.args[i] = args[i]; 914201766a2SElvira Khabirova 915201766a2SElvira Khabirova /* args is the last field in struct ptrace_syscall_info.entry */ 916201766a2SElvira Khabirova return offsetofend(struct ptrace_syscall_info, entry.args); 917201766a2SElvira Khabirova } 918201766a2SElvira Khabirova 919201766a2SElvira Khabirova static unsigned long 920201766a2SElvira Khabirova ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs, 921201766a2SElvira Khabirova struct ptrace_syscall_info *info) 922201766a2SElvira Khabirova { 923201766a2SElvira Khabirova /* 924201766a2SElvira Khabirova * As struct ptrace_syscall_info.entry is currently a subset 925201766a2SElvira Khabirova * of struct ptrace_syscall_info.seccomp, it makes sense to 926201766a2SElvira Khabirova * initialize that subset using ptrace_get_syscall_info_entry(). 927201766a2SElvira Khabirova * This can be reconsidered in the future if these structures 928201766a2SElvira Khabirova * diverge significantly enough. 929201766a2SElvira Khabirova */ 930201766a2SElvira Khabirova ptrace_get_syscall_info_entry(child, regs, info); 931201766a2SElvira Khabirova info->op = PTRACE_SYSCALL_INFO_SECCOMP; 932201766a2SElvira Khabirova info->seccomp.ret_data = child->ptrace_message; 933201766a2SElvira Khabirova 934201766a2SElvira Khabirova /* ret_data is the last field in struct ptrace_syscall_info.seccomp */ 935201766a2SElvira Khabirova return offsetofend(struct ptrace_syscall_info, seccomp.ret_data); 936201766a2SElvira Khabirova } 937201766a2SElvira Khabirova 938201766a2SElvira Khabirova static unsigned long 939201766a2SElvira Khabirova ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs, 940201766a2SElvira Khabirova struct ptrace_syscall_info *info) 941201766a2SElvira Khabirova { 942201766a2SElvira Khabirova info->op = PTRACE_SYSCALL_INFO_EXIT; 943201766a2SElvira Khabirova info->exit.rval = syscall_get_error(child, regs); 944201766a2SElvira Khabirova info->exit.is_error = !!info->exit.rval; 945201766a2SElvira Khabirova if (!info->exit.is_error) 946201766a2SElvira Khabirova info->exit.rval = syscall_get_return_value(child, regs); 947201766a2SElvira Khabirova 948201766a2SElvira Khabirova /* is_error is the last field in struct ptrace_syscall_info.exit */ 949201766a2SElvira Khabirova return offsetofend(struct ptrace_syscall_info, exit.is_error); 950201766a2SElvira Khabirova } 951201766a2SElvira Khabirova 952201766a2SElvira Khabirova static int 953201766a2SElvira Khabirova ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size, 954201766a2SElvira Khabirova void __user *datavp) 955201766a2SElvira Khabirova { 956201766a2SElvira Khabirova struct pt_regs *regs = task_pt_regs(child); 957201766a2SElvira Khabirova struct ptrace_syscall_info info = { 958201766a2SElvira Khabirova .op = PTRACE_SYSCALL_INFO_NONE, 959201766a2SElvira Khabirova .arch = syscall_get_arch(child), 960201766a2SElvira Khabirova .instruction_pointer = instruction_pointer(regs), 961201766a2SElvira Khabirova .stack_pointer = user_stack_pointer(regs), 962201766a2SElvira Khabirova }; 963201766a2SElvira Khabirova unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry); 964201766a2SElvira Khabirova unsigned long write_size; 965201766a2SElvira Khabirova 966201766a2SElvira Khabirova /* 967201766a2SElvira Khabirova * This does not need lock_task_sighand() to access 968201766a2SElvira Khabirova * child->last_siginfo because ptrace_freeze_traced() 969201766a2SElvira Khabirova * called earlier by ptrace_check_attach() ensures that 970201766a2SElvira Khabirova * the tracee cannot go away and clear its last_siginfo. 971201766a2SElvira Khabirova */ 972201766a2SElvira Khabirova switch (child->last_siginfo ? child->last_siginfo->si_code : 0) { 973201766a2SElvira Khabirova case SIGTRAP | 0x80: 974201766a2SElvira Khabirova switch (child->ptrace_message) { 975201766a2SElvira Khabirova case PTRACE_EVENTMSG_SYSCALL_ENTRY: 976201766a2SElvira Khabirova actual_size = ptrace_get_syscall_info_entry(child, regs, 977201766a2SElvira Khabirova &info); 978201766a2SElvira Khabirova break; 979201766a2SElvira Khabirova case PTRACE_EVENTMSG_SYSCALL_EXIT: 980201766a2SElvira Khabirova actual_size = ptrace_get_syscall_info_exit(child, regs, 981201766a2SElvira Khabirova &info); 982201766a2SElvira Khabirova break; 983201766a2SElvira Khabirova } 984201766a2SElvira Khabirova break; 985201766a2SElvira Khabirova case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8): 986201766a2SElvira Khabirova actual_size = ptrace_get_syscall_info_seccomp(child, regs, 987201766a2SElvira Khabirova &info); 988201766a2SElvira Khabirova break; 989201766a2SElvira Khabirova } 990201766a2SElvira Khabirova 991201766a2SElvira Khabirova write_size = min(actual_size, user_size); 992201766a2SElvira Khabirova return copy_to_user(datavp, &info, write_size) ? -EFAULT : actual_size; 993201766a2SElvira Khabirova } 994201766a2SElvira Khabirova #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ 9952225a122SSuresh Siddha 9961da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 9974abf9869SNamhyung Kim unsigned long addr, unsigned long data) 9981da177e4SLinus Torvalds { 999fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 10001da177e4SLinus Torvalds int ret = -EIO; 1001ae7795bcSEric W. Biederman kernel_siginfo_t siginfo, *si; 10029fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 10039fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 1004fca26f26STejun Heo unsigned long flags; 10051da177e4SLinus Torvalds 10061da177e4SLinus Torvalds switch (request) { 100716c3e389SRoland McGrath case PTRACE_PEEKTEXT: 100816c3e389SRoland McGrath case PTRACE_PEEKDATA: 100916c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 101016c3e389SRoland McGrath case PTRACE_POKETEXT: 101116c3e389SRoland McGrath case PTRACE_POKEDATA: 101216c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 101316c3e389SRoland McGrath 10141da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 10151da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 10161da177e4SLinus Torvalds #endif 10171da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 10181da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 10191da177e4SLinus Torvalds break; 10201da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 10219fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 10221da177e4SLinus Torvalds break; 1023e16b2781SRoland McGrath 102484c751bdSAndrey Vagin case PTRACE_PEEKSIGINFO: 102584c751bdSAndrey Vagin ret = ptrace_peek_siginfo(child, addr, data); 102684c751bdSAndrey Vagin break; 102784c751bdSAndrey Vagin 10281da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 1029e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 1030e16b2781SRoland McGrath if (!ret) 10319fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 10321da177e4SLinus Torvalds break; 1033e16b2781SRoland McGrath 10341da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 10354cd2e0e7SEric W. Biederman ret = copy_siginfo_from_user(&siginfo, datavp); 10364cd2e0e7SEric W. Biederman if (!ret) 1037e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 10381da177e4SLinus Torvalds break; 1039e16b2781SRoland McGrath 1040fcfc2aa0SAndrei Vagin case PTRACE_GETSIGMASK: { 1041fcfc2aa0SAndrei Vagin sigset_t *mask; 1042fcfc2aa0SAndrei Vagin 104329000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 104429000caeSAndrey Vagin ret = -EINVAL; 104529000caeSAndrey Vagin break; 104629000caeSAndrey Vagin } 104729000caeSAndrey Vagin 1048fcfc2aa0SAndrei Vagin if (test_tsk_restore_sigmask(child)) 1049fcfc2aa0SAndrei Vagin mask = &child->saved_sigmask; 1050fcfc2aa0SAndrei Vagin else 1051fcfc2aa0SAndrei Vagin mask = &child->blocked; 1052fcfc2aa0SAndrei Vagin 1053fcfc2aa0SAndrei Vagin if (copy_to_user(datavp, mask, sizeof(sigset_t))) 105429000caeSAndrey Vagin ret = -EFAULT; 105529000caeSAndrey Vagin else 105629000caeSAndrey Vagin ret = 0; 105729000caeSAndrey Vagin 105829000caeSAndrey Vagin break; 1059fcfc2aa0SAndrei Vagin } 106029000caeSAndrey Vagin 106129000caeSAndrey Vagin case PTRACE_SETSIGMASK: { 106229000caeSAndrey Vagin sigset_t new_set; 106329000caeSAndrey Vagin 106429000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 106529000caeSAndrey Vagin ret = -EINVAL; 106629000caeSAndrey Vagin break; 106729000caeSAndrey Vagin } 106829000caeSAndrey Vagin 106929000caeSAndrey Vagin if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { 107029000caeSAndrey Vagin ret = -EFAULT; 107129000caeSAndrey Vagin break; 107229000caeSAndrey Vagin } 107329000caeSAndrey Vagin 107429000caeSAndrey Vagin sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); 107529000caeSAndrey Vagin 107629000caeSAndrey Vagin /* 107729000caeSAndrey Vagin * Every thread does recalc_sigpending() after resume, so 107829000caeSAndrey Vagin * retarget_shared_pending() and recalc_sigpending() are not 107929000caeSAndrey Vagin * called here. 108029000caeSAndrey Vagin */ 108129000caeSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 108229000caeSAndrey Vagin child->blocked = new_set; 108329000caeSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 108429000caeSAndrey Vagin 1085fcfc2aa0SAndrei Vagin clear_tsk_restore_sigmask(child); 1086fcfc2aa0SAndrei Vagin 108729000caeSAndrey Vagin ret = 0; 108829000caeSAndrey Vagin break; 108929000caeSAndrey Vagin } 109029000caeSAndrey Vagin 1091fca26f26STejun Heo case PTRACE_INTERRUPT: 1092fca26f26STejun Heo /* 1093fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 1094fca26f26STejun Heo * control. At least one trap is guaranteed to happen 1095fca26f26STejun Heo * after this request. If @child is already trapped, the 1096fca26f26STejun Heo * current trap is not disturbed and another trap will 1097fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 1098fca26f26STejun Heo * 1099fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 1100fca26f26STejun Heo * the pending condition is cleared regardless. 1101fca26f26STejun Heo */ 1102fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 1103fca26f26STejun Heo break; 1104fca26f26STejun Heo 1105544b2c91STejun Heo /* 1106544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 1107544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 1108544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 1109544b2c91STejun Heo * tracee into STOP. 1110544b2c91STejun Heo */ 1111fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 1112910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 1113544b2c91STejun Heo 1114544b2c91STejun Heo unlock_task_sighand(child, &flags); 1115544b2c91STejun Heo ret = 0; 1116544b2c91STejun Heo break; 1117544b2c91STejun Heo 1118544b2c91STejun Heo case PTRACE_LISTEN: 1119544b2c91STejun Heo /* 1120544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 1121544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 1122544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 1123544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 1124544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 1125544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 1126544b2c91STejun Heo */ 1127544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 1128544b2c91STejun Heo break; 1129544b2c91STejun Heo 1130544b2c91STejun Heo si = child->last_siginfo; 1131f9d81f61SOleg Nesterov if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { 1132544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 1133544b2c91STejun Heo /* 1134f9d81f61SOleg Nesterov * If NOTIFY is set, it means event happened between 1135f9d81f61SOleg Nesterov * start of this trap and now. Trigger re-trap. 1136544b2c91STejun Heo */ 1137544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 1138910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 1139fca26f26STejun Heo ret = 0; 1140f9d81f61SOleg Nesterov } 1141f9d81f61SOleg Nesterov unlock_task_sighand(child, &flags); 1142fca26f26STejun Heo break; 1143fca26f26STejun Heo 11441bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 11451bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 11461bcf5482SAlexey Dobriyan break; 114736df29d7SRoland McGrath 11489c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 11499c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 1150e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 11519c1a1259SMike Frysinger unsigned long tmp = 0; 11529c1a1259SMike Frysinger 1153e0129ef9SOleg Nesterov ret = -ESRCH; 1154e0129ef9SOleg Nesterov if (!mm) 1155e0129ef9SOleg Nesterov break; 1156e0129ef9SOleg Nesterov 11579c1a1259SMike Frysinger switch (addr) { 11589c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 1159e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 11609c1a1259SMike Frysinger break; 11619c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 1162e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 11639c1a1259SMike Frysinger break; 11649c1a1259SMike Frysinger default: 11659c1a1259SMike Frysinger break; 11669c1a1259SMike Frysinger } 1167e0129ef9SOleg Nesterov mmput(mm); 11689c1a1259SMike Frysinger 11699fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 11709c1a1259SMike Frysinger break; 11719c1a1259SMike Frysinger } 11729c1a1259SMike Frysinger #endif 11739c1a1259SMike Frysinger 117436df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 117536df29d7SRoland McGrath case PTRACE_SINGLESTEP: 117636df29d7SRoland McGrath #endif 11775b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 11785b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 11795b88abbfSRoland McGrath #endif 118036df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 118136df29d7SRoland McGrath case PTRACE_SYSEMU: 118236df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 118336df29d7SRoland McGrath #endif 118436df29d7SRoland McGrath case PTRACE_SYSCALL: 118536df29d7SRoland McGrath case PTRACE_CONT: 118636df29d7SRoland McGrath return ptrace_resume(child, request, data); 118736df29d7SRoland McGrath 118836df29d7SRoland McGrath case PTRACE_KILL: 118936df29d7SRoland McGrath if (child->exit_state) /* already dead */ 119036df29d7SRoland McGrath return 0; 119136df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 119236df29d7SRoland McGrath 11932225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 11942225a122SSuresh Siddha case PTRACE_GETREGSET: 119529000caeSAndrey Vagin case PTRACE_SETREGSET: { 11962225a122SSuresh Siddha struct iovec kiov; 11979fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 11982225a122SSuresh Siddha 119996d4f267SLinus Torvalds if (!access_ok(uiov, sizeof(*uiov))) 12002225a122SSuresh Siddha return -EFAULT; 12012225a122SSuresh Siddha 12022225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 12032225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 12042225a122SSuresh Siddha return -EFAULT; 12052225a122SSuresh Siddha 12062225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 12072225a122SSuresh Siddha if (!ret) 12082225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 12092225a122SSuresh Siddha break; 12102225a122SSuresh Siddha } 1211201766a2SElvira Khabirova 1212201766a2SElvira Khabirova case PTRACE_GET_SYSCALL_INFO: 1213201766a2SElvira Khabirova ret = ptrace_get_syscall_info(child, addr, datavp); 1214201766a2SElvira Khabirova break; 12152225a122SSuresh Siddha #endif 1216f8e529edSTycho Andersen 1217f8e529edSTycho Andersen case PTRACE_SECCOMP_GET_FILTER: 1218f8e529edSTycho Andersen ret = seccomp_get_filter(child, addr, datavp); 1219f8e529edSTycho Andersen break; 1220f8e529edSTycho Andersen 122126500475STycho Andersen case PTRACE_SECCOMP_GET_METADATA: 122226500475STycho Andersen ret = seccomp_get_metadata(child, addr, datavp); 122326500475STycho Andersen break; 122426500475STycho Andersen 12251da177e4SLinus Torvalds default: 12261da177e4SLinus Torvalds break; 12271da177e4SLinus Torvalds } 12281da177e4SLinus Torvalds 12291da177e4SLinus Torvalds return ret; 12301da177e4SLinus Torvalds } 1231481bed45SChristoph Hellwig 12320ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 12330ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 12340ac15559SChristoph Hellwig #endif 12350ac15559SChristoph Hellwig 12364abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 12374abf9869SNamhyung Kim unsigned long, data) 1238481bed45SChristoph Hellwig { 1239481bed45SChristoph Hellwig struct task_struct *child; 1240481bed45SChristoph Hellwig long ret; 1241481bed45SChristoph Hellwig 12426b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 12436b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 12446ea6dd93SHaavard Skinnemoen if (!ret) 12456ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 1246481bed45SChristoph Hellwig goto out; 12476b9c7ed8SChristoph Hellwig } 12486b9c7ed8SChristoph Hellwig 12492ee08260SMike Rapoport child = find_get_task_by_vpid(pid); 12502ee08260SMike Rapoport if (!child) { 12512ee08260SMike Rapoport ret = -ESRCH; 12526b9c7ed8SChristoph Hellwig goto out; 12536b9c7ed8SChristoph Hellwig } 1254481bed45SChristoph Hellwig 12553544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1256aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 12570ac15559SChristoph Hellwig /* 12580ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 12590ac15559SChristoph Hellwig * a ptrace attach. 12600ac15559SChristoph Hellwig */ 12610ac15559SChristoph Hellwig if (!ret) 12620ac15559SChristoph Hellwig arch_ptrace_attach(child); 1263005f18dfSChristoph Hellwig goto out_put_task_struct; 1264481bed45SChristoph Hellwig } 1265481bed45SChristoph Hellwig 1266fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1267fca26f26STejun Heo request == PTRACE_INTERRUPT); 1268481bed45SChristoph Hellwig if (ret < 0) 1269481bed45SChristoph Hellwig goto out_put_task_struct; 1270481bed45SChristoph Hellwig 1271481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 12729899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 12739899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 1274481bed45SChristoph Hellwig 1275481bed45SChristoph Hellwig out_put_task_struct: 1276481bed45SChristoph Hellwig put_task_struct(child); 1277481bed45SChristoph Hellwig out: 1278481bed45SChristoph Hellwig return ret; 1279481bed45SChristoph Hellwig } 128076647323SAlexey Dobriyan 12814abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 12824abf9869SNamhyung Kim unsigned long data) 128376647323SAlexey Dobriyan { 128476647323SAlexey Dobriyan unsigned long tmp; 128576647323SAlexey Dobriyan int copied; 128676647323SAlexey Dobriyan 128784d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); 128876647323SAlexey Dobriyan if (copied != sizeof(tmp)) 128976647323SAlexey Dobriyan return -EIO; 129076647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 129176647323SAlexey Dobriyan } 1292f284ce72SAlexey Dobriyan 12934abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 12944abf9869SNamhyung Kim unsigned long data) 1295f284ce72SAlexey Dobriyan { 1296f284ce72SAlexey Dobriyan int copied; 1297f284ce72SAlexey Dobriyan 129884d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &data, sizeof(data), 1299f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1300f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 1301f284ce72SAlexey Dobriyan } 1302032d82d9SRoland McGrath 130396b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 1304032d82d9SRoland McGrath 1305032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 1306032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 1307032d82d9SRoland McGrath { 1308032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 1309032d82d9SRoland McGrath compat_ulong_t word; 1310ae7795bcSEric W. Biederman kernel_siginfo_t siginfo; 1311032d82d9SRoland McGrath int ret; 1312032d82d9SRoland McGrath 1313032d82d9SRoland McGrath switch (request) { 1314032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 1315032d82d9SRoland McGrath case PTRACE_PEEKDATA: 131684d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &word, sizeof(word), 1317f307ab6dSLorenzo Stoakes FOLL_FORCE); 1318032d82d9SRoland McGrath if (ret != sizeof(word)) 1319032d82d9SRoland McGrath ret = -EIO; 1320032d82d9SRoland McGrath else 1321032d82d9SRoland McGrath ret = put_user(word, datap); 1322032d82d9SRoland McGrath break; 1323032d82d9SRoland McGrath 1324032d82d9SRoland McGrath case PTRACE_POKETEXT: 1325032d82d9SRoland McGrath case PTRACE_POKEDATA: 132684d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &data, sizeof(data), 1327f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1328032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 1329032d82d9SRoland McGrath break; 1330032d82d9SRoland McGrath 1331032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 1332032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 1333032d82d9SRoland McGrath break; 1334032d82d9SRoland McGrath 1335e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 1336e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 1337e16b2781SRoland McGrath if (!ret) 1338e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 1339e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 1340e16b2781SRoland McGrath &siginfo); 1341e16b2781SRoland McGrath break; 1342e16b2781SRoland McGrath 1343e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 13444cd2e0e7SEric W. Biederman ret = copy_siginfo_from_user32( 13454cd2e0e7SEric W. Biederman &siginfo, (struct compat_siginfo __user *) datap); 13464cd2e0e7SEric W. Biederman if (!ret) 1347e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 1348e16b2781SRoland McGrath break; 13492225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 13502225a122SSuresh Siddha case PTRACE_GETREGSET: 13512225a122SSuresh Siddha case PTRACE_SETREGSET: 13522225a122SSuresh Siddha { 13532225a122SSuresh Siddha struct iovec kiov; 13542225a122SSuresh Siddha struct compat_iovec __user *uiov = 13552225a122SSuresh Siddha (struct compat_iovec __user *) datap; 13562225a122SSuresh Siddha compat_uptr_t ptr; 13572225a122SSuresh Siddha compat_size_t len; 13582225a122SSuresh Siddha 135996d4f267SLinus Torvalds if (!access_ok(uiov, sizeof(*uiov))) 13602225a122SSuresh Siddha return -EFAULT; 13612225a122SSuresh Siddha 13622225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 13632225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 13642225a122SSuresh Siddha return -EFAULT; 13652225a122SSuresh Siddha 13662225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 13672225a122SSuresh Siddha kiov.iov_len = len; 13682225a122SSuresh Siddha 13692225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 13702225a122SSuresh Siddha if (!ret) 13712225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 13722225a122SSuresh Siddha break; 13732225a122SSuresh Siddha } 13742225a122SSuresh Siddha #endif 1375e16b2781SRoland McGrath 1376032d82d9SRoland McGrath default: 1377032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 1378032d82d9SRoland McGrath } 1379032d82d9SRoland McGrath 1380032d82d9SRoland McGrath return ret; 1381032d82d9SRoland McGrath } 1382c269f196SRoland McGrath 138362a6fa97SHeiko Carstens COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, 138462a6fa97SHeiko Carstens compat_long_t, addr, compat_long_t, data) 1385c269f196SRoland McGrath { 1386c269f196SRoland McGrath struct task_struct *child; 1387c269f196SRoland McGrath long ret; 1388c269f196SRoland McGrath 1389c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1390c269f196SRoland McGrath ret = ptrace_traceme(); 1391c269f196SRoland McGrath goto out; 1392c269f196SRoland McGrath } 1393c269f196SRoland McGrath 13942ee08260SMike Rapoport child = find_get_task_by_vpid(pid); 13952ee08260SMike Rapoport if (!child) { 13962ee08260SMike Rapoport ret = -ESRCH; 1397c269f196SRoland McGrath goto out; 1398c269f196SRoland McGrath } 1399c269f196SRoland McGrath 14003544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1401aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 1402c269f196SRoland McGrath /* 1403c269f196SRoland McGrath * Some architectures need to do book-keeping after 1404c269f196SRoland McGrath * a ptrace attach. 1405c269f196SRoland McGrath */ 1406c269f196SRoland McGrath if (!ret) 1407c269f196SRoland McGrath arch_ptrace_attach(child); 1408c269f196SRoland McGrath goto out_put_task_struct; 1409c269f196SRoland McGrath } 1410c269f196SRoland McGrath 1411fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1412fca26f26STejun Heo request == PTRACE_INTERRUPT); 14139899d11fSOleg Nesterov if (!ret) { 1414c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 14159899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 14169899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 14179899d11fSOleg Nesterov } 1418c269f196SRoland McGrath 1419c269f196SRoland McGrath out_put_task_struct: 1420c269f196SRoland McGrath put_task_struct(child); 1421c269f196SRoland McGrath out: 1422c269f196SRoland McGrath return ret; 1423c269f196SRoland McGrath } 142496b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1425