11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/kernel/ptrace.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * (C) Copyright 1999 Linus Torvalds 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * Common interfaces for "ptrace()" which we do not want 71da177e4SLinus Torvalds * to continually duplicate across every architecture. 81da177e4SLinus Torvalds */ 91da177e4SLinus Torvalds 10c59ede7bSRandy.Dunlap #include <linux/capability.h> 119984de1aSPaul Gortmaker #include <linux/export.h> 121da177e4SLinus Torvalds #include <linux/sched.h> 136e84f315SIngo Molnar #include <linux/sched/mm.h> 14f7ccbae4SIngo Molnar #include <linux/sched/coredump.h> 1529930025SIngo Molnar #include <linux/sched/task.h> 161da177e4SLinus Torvalds #include <linux/errno.h> 171da177e4SLinus Torvalds #include <linux/mm.h> 181da177e4SLinus Torvalds #include <linux/highmem.h> 191da177e4SLinus Torvalds #include <linux/pagemap.h> 201da177e4SLinus Torvalds #include <linux/ptrace.h> 211da177e4SLinus Torvalds #include <linux/security.h> 227ed20e1aSJesper Juhl #include <linux/signal.h> 23a27bb332SKent Overstreet #include <linux/uio.h> 24a5cb013dSAl Viro #include <linux/audit.h> 25b488893aSPavel Emelyanov #include <linux/pid_namespace.h> 26f17d30a8SAdrian Bunk #include <linux/syscalls.h> 273a709703SRoland McGrath #include <linux/uaccess.h> 282225a122SSuresh Siddha #include <linux/regset.h> 29bf26c018SFrederic Weisbecker #include <linux/hw_breakpoint.h> 30f701e5b7SVladimir Zapolskiy #include <linux/cn_proc.h> 3184c751bdSAndrey Vagin #include <linux/compat.h> 321da177e4SLinus Torvalds 3384d77d3fSEric W. Biederman /* 3484d77d3fSEric W. Biederman * Access another process' address space via ptrace. 3584d77d3fSEric W. Biederman * Source/target buffer must be kernel space, 3684d77d3fSEric W. Biederman * Do not walk the page table directly, use get_user_pages 3784d77d3fSEric W. Biederman */ 3884d77d3fSEric W. Biederman int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, 3984d77d3fSEric W. Biederman void *buf, int len, unsigned int gup_flags) 4084d77d3fSEric W. Biederman { 4184d77d3fSEric W. Biederman struct mm_struct *mm; 4284d77d3fSEric W. Biederman int ret; 4384d77d3fSEric W. Biederman 4484d77d3fSEric W. Biederman mm = get_task_mm(tsk); 4584d77d3fSEric W. Biederman if (!mm) 4684d77d3fSEric W. Biederman return 0; 4784d77d3fSEric W. Biederman 4884d77d3fSEric W. Biederman if (!tsk->ptrace || 4984d77d3fSEric W. Biederman (current != tsk->parent) || 5084d77d3fSEric W. Biederman ((get_dumpable(mm) != SUID_DUMP_USER) && 5184d77d3fSEric W. Biederman !ptracer_capable(tsk, mm->user_ns))) { 5284d77d3fSEric W. Biederman mmput(mm); 5384d77d3fSEric W. Biederman return 0; 5484d77d3fSEric W. Biederman } 5584d77d3fSEric W. Biederman 5684d77d3fSEric W. Biederman ret = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags); 5784d77d3fSEric W. Biederman mmput(mm); 5884d77d3fSEric W. Biederman 5984d77d3fSEric W. Biederman return ret; 6084d77d3fSEric W. Biederman } 6184d77d3fSEric W. Biederman 62bf53de90SMarkus Metzger 63bf53de90SMarkus Metzger /* 641da177e4SLinus Torvalds * ptrace a task: make the debugger its new parent and 651da177e4SLinus Torvalds * move it to the ptrace list. 661da177e4SLinus Torvalds * 671da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 681da177e4SLinus Torvalds */ 6936c8b586SIngo Molnar void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) 701da177e4SLinus Torvalds { 71f470021aSRoland McGrath BUG_ON(!list_empty(&child->ptrace_entry)); 72f470021aSRoland McGrath list_add(&child->ptrace_entry, &new_parent->ptraced); 731da177e4SLinus Torvalds child->parent = new_parent; 7464b875f7SEric W. Biederman rcu_read_lock(); 7564b875f7SEric W. Biederman child->ptracer_cred = get_cred(__task_cred(new_parent)); 7664b875f7SEric W. Biederman rcu_read_unlock(); 771da177e4SLinus Torvalds } 781da177e4SLinus Torvalds 79e3bd058fSTejun Heo /** 80e3bd058fSTejun Heo * __ptrace_unlink - unlink ptracee and restore its execution state 81e3bd058fSTejun Heo * @child: ptracee to be unlinked 821da177e4SLinus Torvalds * 830e9f0a4aSTejun Heo * Remove @child from the ptrace list, move it back to the original parent, 840e9f0a4aSTejun Heo * and restore the execution state so that it conforms to the group stop 850e9f0a4aSTejun Heo * state. 860e9f0a4aSTejun Heo * 870e9f0a4aSTejun Heo * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer 880e9f0a4aSTejun Heo * exiting. For PTRACE_DETACH, unless the ptracee has been killed between 890e9f0a4aSTejun Heo * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. 900e9f0a4aSTejun Heo * If the ptracer is exiting, the ptracee can be in any state. 910e9f0a4aSTejun Heo * 920e9f0a4aSTejun Heo * After detach, the ptracee should be in a state which conforms to the 930e9f0a4aSTejun Heo * group stop. If the group is stopped or in the process of stopping, the 940e9f0a4aSTejun Heo * ptracee should be put into TASK_STOPPED; otherwise, it should be woken 950e9f0a4aSTejun Heo * up from TASK_TRACED. 960e9f0a4aSTejun Heo * 970e9f0a4aSTejun Heo * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, 980e9f0a4aSTejun Heo * it goes through TRACED -> RUNNING -> STOPPED transition which is similar 990e9f0a4aSTejun Heo * to but in the opposite direction of what happens while attaching to a 1000e9f0a4aSTejun Heo * stopped task. However, in this direction, the intermediate RUNNING 1010e9f0a4aSTejun Heo * state is not hidden even from the current ptracer and if it immediately 1020e9f0a4aSTejun Heo * re-attaches and performs a WNOHANG wait(2), it may fail. 103e3bd058fSTejun Heo * 104e3bd058fSTejun Heo * CONTEXT: 105e3bd058fSTejun Heo * write_lock_irq(tasklist_lock) 1061da177e4SLinus Torvalds */ 10736c8b586SIngo Molnar void __ptrace_unlink(struct task_struct *child) 1081da177e4SLinus Torvalds { 10964b875f7SEric W. Biederman const struct cred *old_cred; 1105ecfbae0SOleg Nesterov BUG_ON(!child->ptrace); 1115ecfbae0SOleg Nesterov 1120a5bf409SAles Novak clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 1130a5bf409SAles Novak 1141da177e4SLinus Torvalds child->parent = child->real_parent; 115f470021aSRoland McGrath list_del_init(&child->ptrace_entry); 11664b875f7SEric W. Biederman old_cred = child->ptracer_cred; 11764b875f7SEric W. Biederman child->ptracer_cred = NULL; 11864b875f7SEric W. Biederman put_cred(old_cred); 1191da177e4SLinus Torvalds 1201da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 1211333ab03SOleg Nesterov child->ptrace = 0; 1221da177e4SLinus Torvalds /* 12373ddff2bSTejun Heo * Clear all pending traps and TRAPPING. TRAPPING should be 12473ddff2bSTejun Heo * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. 12573ddff2bSTejun Heo */ 12673ddff2bSTejun Heo task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); 12773ddff2bSTejun Heo task_clear_jobctl_trapping(child); 12873ddff2bSTejun Heo 12973ddff2bSTejun Heo /* 130a8f072c1STejun Heo * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and 1310e9f0a4aSTejun Heo * @child isn't dead. 1321da177e4SLinus Torvalds */ 1330e9f0a4aSTejun Heo if (!(child->flags & PF_EXITING) && 1340e9f0a4aSTejun Heo (child->signal->flags & SIGNAL_STOP_STOPPED || 1358a88951bSOleg Nesterov child->signal->group_stop_count)) { 136a8f072c1STejun Heo child->jobctl |= JOBCTL_STOP_PENDING; 1370e9f0a4aSTejun Heo 1380e9f0a4aSTejun Heo /* 1398a88951bSOleg Nesterov * This is only possible if this thread was cloned by the 1408a88951bSOleg Nesterov * traced task running in the stopped group, set the signal 1418a88951bSOleg Nesterov * for the future reports. 1428a88951bSOleg Nesterov * FIXME: we should change ptrace_init_task() to handle this 1438a88951bSOleg Nesterov * case. 1448a88951bSOleg Nesterov */ 1458a88951bSOleg Nesterov if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) 1468a88951bSOleg Nesterov child->jobctl |= SIGSTOP; 1478a88951bSOleg Nesterov } 1488a88951bSOleg Nesterov 1498a88951bSOleg Nesterov /* 1500e9f0a4aSTejun Heo * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick 1510e9f0a4aSTejun Heo * @child in the butt. Note that @resume should be used iff @child 1520e9f0a4aSTejun Heo * is in TASK_TRACED; otherwise, we might unduly disrupt 1530e9f0a4aSTejun Heo * TASK_KILLABLE sleeps. 1540e9f0a4aSTejun Heo */ 155a8f072c1STejun Heo if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) 156910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 1570e9f0a4aSTejun Heo 1581da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 1591da177e4SLinus Torvalds } 1601da177e4SLinus Torvalds 1619899d11fSOleg Nesterov /* Ensure that nothing can wake it up, even SIGKILL */ 1629899d11fSOleg Nesterov static bool ptrace_freeze_traced(struct task_struct *task) 1639899d11fSOleg Nesterov { 1649899d11fSOleg Nesterov bool ret = false; 1659899d11fSOleg Nesterov 1669899d11fSOleg Nesterov /* Lockless, nobody but us can set this flag */ 1679899d11fSOleg Nesterov if (task->jobctl & JOBCTL_LISTENING) 1689899d11fSOleg Nesterov return ret; 1699899d11fSOleg Nesterov 1709899d11fSOleg Nesterov spin_lock_irq(&task->sighand->siglock); 1719899d11fSOleg Nesterov if (task_is_traced(task) && !__fatal_signal_pending(task)) { 1729899d11fSOleg Nesterov task->state = __TASK_TRACED; 1739899d11fSOleg Nesterov ret = true; 1749899d11fSOleg Nesterov } 1759899d11fSOleg Nesterov spin_unlock_irq(&task->sighand->siglock); 1769899d11fSOleg Nesterov 1779899d11fSOleg Nesterov return ret; 1789899d11fSOleg Nesterov } 1799899d11fSOleg Nesterov 1809899d11fSOleg Nesterov static void ptrace_unfreeze_traced(struct task_struct *task) 1819899d11fSOleg Nesterov { 1829899d11fSOleg Nesterov if (task->state != __TASK_TRACED) 1839899d11fSOleg Nesterov return; 1849899d11fSOleg Nesterov 1859899d11fSOleg Nesterov WARN_ON(!task->ptrace || task->parent != current); 1869899d11fSOleg Nesterov 1879899d11fSOleg Nesterov spin_lock_irq(&task->sighand->siglock); 1889899d11fSOleg Nesterov if (__fatal_signal_pending(task)) 1899899d11fSOleg Nesterov wake_up_state(task, __TASK_TRACED); 1909899d11fSOleg Nesterov else 1919899d11fSOleg Nesterov task->state = TASK_TRACED; 1929899d11fSOleg Nesterov spin_unlock_irq(&task->sighand->siglock); 1939899d11fSOleg Nesterov } 1949899d11fSOleg Nesterov 195755e276bSTejun Heo /** 196755e276bSTejun Heo * ptrace_check_attach - check whether ptracee is ready for ptrace operation 197755e276bSTejun Heo * @child: ptracee to check for 198755e276bSTejun Heo * @ignore_state: don't check whether @child is currently %TASK_TRACED 199755e276bSTejun Heo * 200755e276bSTejun Heo * Check whether @child is being ptraced by %current and ready for further 201755e276bSTejun Heo * ptrace operations. If @ignore_state is %false, @child also should be in 202755e276bSTejun Heo * %TASK_TRACED state and on return the child is guaranteed to be traced 203755e276bSTejun Heo * and not executing. If @ignore_state is %true, @child can be in any 204755e276bSTejun Heo * state. 205755e276bSTejun Heo * 206755e276bSTejun Heo * CONTEXT: 207755e276bSTejun Heo * Grabs and releases tasklist_lock and @child->sighand->siglock. 208755e276bSTejun Heo * 209755e276bSTejun Heo * RETURNS: 210755e276bSTejun Heo * 0 on success, -ESRCH if %child is not ready. 2111da177e4SLinus Torvalds */ 212edea0d03SOleg Nesterov static int ptrace_check_attach(struct task_struct *child, bool ignore_state) 2131da177e4SLinus Torvalds { 2141da177e4SLinus Torvalds int ret = -ESRCH; 2151da177e4SLinus Torvalds 2161da177e4SLinus Torvalds /* 2171da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 2181da177e4SLinus Torvalds * possible race where someone else was tracing our child and 2191da177e4SLinus Torvalds * detached between these two checks. After this locked check, 2201da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 2211da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 2221da177e4SLinus Torvalds */ 2231da177e4SLinus Torvalds read_lock(&tasklist_lock); 2249899d11fSOleg Nesterov if (child->ptrace && child->parent == current) { 2259899d11fSOleg Nesterov WARN_ON(child->state == __TASK_TRACED); 226c0c0b649SOleg Nesterov /* 227c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 228c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 229c0c0b649SOleg Nesterov */ 2309899d11fSOleg Nesterov if (ignore_state || ptrace_freeze_traced(child)) 231321fb561SOleg Nesterov ret = 0; 2321da177e4SLinus Torvalds } 2331da177e4SLinus Torvalds read_unlock(&tasklist_lock); 2341da177e4SLinus Torvalds 2359899d11fSOleg Nesterov if (!ret && !ignore_state) { 2369899d11fSOleg Nesterov if (!wait_task_inactive(child, __TASK_TRACED)) { 2379899d11fSOleg Nesterov /* 2389899d11fSOleg Nesterov * This can only happen if may_ptrace_stop() fails and 2399899d11fSOleg Nesterov * ptrace_stop() changes ->state back to TASK_RUNNING, 2409899d11fSOleg Nesterov * so we should not worry about leaking __TASK_TRACED. 2419899d11fSOleg Nesterov */ 2429899d11fSOleg Nesterov WARN_ON(child->state == __TASK_TRACED); 2439899d11fSOleg Nesterov ret = -ESRCH; 2449899d11fSOleg Nesterov } 2459899d11fSOleg Nesterov } 2461da177e4SLinus Torvalds 2471da177e4SLinus Torvalds return ret; 2481da177e4SLinus Torvalds } 2491da177e4SLinus Torvalds 25069f594a3SEric Paris static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) 25169f594a3SEric Paris { 25269f594a3SEric Paris if (mode & PTRACE_MODE_NOAUDIT) 25369f594a3SEric Paris return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); 25469f594a3SEric Paris else 25569f594a3SEric Paris return has_ns_capability(current, ns, CAP_SYS_PTRACE); 25669f594a3SEric Paris } 25769f594a3SEric Paris 2589f99798fSTetsuo Handa /* Returns 0 on success, -errno on denial. */ 2599f99798fSTetsuo Handa static int __ptrace_may_access(struct task_struct *task, unsigned int mode) 260ab8d11beSMiklos Szeredi { 261c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 262bfedb589SEric W. Biederman struct mm_struct *mm; 263caaee623SJann Horn kuid_t caller_uid; 264caaee623SJann Horn kgid_t caller_gid; 265caaee623SJann Horn 266caaee623SJann Horn if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { 267caaee623SJann Horn WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); 268caaee623SJann Horn return -EPERM; 269caaee623SJann Horn } 270b6dff3ecSDavid Howells 271df26c40eSEric W. Biederman /* May we inspect the given task? 272df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 273df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 274df26c40eSEric W. Biederman * 275df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 276df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 277df26c40eSEric W. Biederman * or halting the specified task is impossible. 278df26c40eSEric W. Biederman */ 279caaee623SJann Horn 280df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 28173af963fSMark Grondona if (same_thread_group(task, current)) 282df26c40eSEric W. Biederman return 0; 283c69e8d9cSDavid Howells rcu_read_lock(); 284caaee623SJann Horn if (mode & PTRACE_MODE_FSCREDS) { 285caaee623SJann Horn caller_uid = cred->fsuid; 286caaee623SJann Horn caller_gid = cred->fsgid; 287caaee623SJann Horn } else { 288caaee623SJann Horn /* 289caaee623SJann Horn * Using the euid would make more sense here, but something 290caaee623SJann Horn * in userland might rely on the old behavior, and this 291caaee623SJann Horn * shouldn't be a security problem since 292caaee623SJann Horn * PTRACE_MODE_REALCREDS implies that the caller explicitly 293caaee623SJann Horn * used a syscall that requests access to another process 294caaee623SJann Horn * (and not a filesystem syscall to procfs). 295caaee623SJann Horn */ 296caaee623SJann Horn caller_uid = cred->uid; 297caaee623SJann Horn caller_gid = cred->gid; 298caaee623SJann Horn } 299c69e8d9cSDavid Howells tcred = __task_cred(task); 300caaee623SJann Horn if (uid_eq(caller_uid, tcred->euid) && 301caaee623SJann Horn uid_eq(caller_uid, tcred->suid) && 302caaee623SJann Horn uid_eq(caller_uid, tcred->uid) && 303caaee623SJann Horn gid_eq(caller_gid, tcred->egid) && 304caaee623SJann Horn gid_eq(caller_gid, tcred->sgid) && 305caaee623SJann Horn gid_eq(caller_gid, tcred->gid)) 3068409cca7SSerge E. Hallyn goto ok; 307c4a4d603SEric W. Biederman if (ptrace_has_cap(tcred->user_ns, mode)) 3088409cca7SSerge E. Hallyn goto ok; 309c69e8d9cSDavid Howells rcu_read_unlock(); 310ab8d11beSMiklos Szeredi return -EPERM; 3118409cca7SSerge E. Hallyn ok: 312c69e8d9cSDavid Howells rcu_read_unlock(); 313bfedb589SEric W. Biederman mm = task->mm; 314bfedb589SEric W. Biederman if (mm && 315bfedb589SEric W. Biederman ((get_dumpable(mm) != SUID_DUMP_USER) && 316bfedb589SEric W. Biederman !ptrace_has_cap(mm->user_ns, mode))) 317ab8d11beSMiklos Szeredi return -EPERM; 318ab8d11beSMiklos Szeredi 3199e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 320ab8d11beSMiklos Szeredi } 321ab8d11beSMiklos Szeredi 322006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 323ab8d11beSMiklos Szeredi { 324ab8d11beSMiklos Szeredi int err; 325ab8d11beSMiklos Szeredi task_lock(task); 326006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 327ab8d11beSMiklos Szeredi task_unlock(task); 3283a709703SRoland McGrath return !err; 329ab8d11beSMiklos Szeredi } 330ab8d11beSMiklos Szeredi 3313544d72aSTejun Heo static int ptrace_attach(struct task_struct *task, long request, 332aa9147c9SDenys Vlasenko unsigned long addr, 3333544d72aSTejun Heo unsigned long flags) 3341da177e4SLinus Torvalds { 3353544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 3361da177e4SLinus Torvalds int retval; 337f5b40e36SLinus Torvalds 3383544d72aSTejun Heo retval = -EIO; 339aa9147c9SDenys Vlasenko if (seize) { 340aa9147c9SDenys Vlasenko if (addr != 0) 3413544d72aSTejun Heo goto out; 342aa9147c9SDenys Vlasenko if (flags & ~(unsigned long)PTRACE_O_MASK) 343aa9147c9SDenys Vlasenko goto out; 344aa9147c9SDenys Vlasenko flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); 345aa9147c9SDenys Vlasenko } else { 346aa9147c9SDenys Vlasenko flags = PT_PTRACED; 347aa9147c9SDenys Vlasenko } 3483544d72aSTejun Heo 349a5cb013dSAl Viro audit_ptrace(task); 350a5cb013dSAl Viro 3511da177e4SLinus Torvalds retval = -EPERM; 352b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 353b79b7ba9SOleg Nesterov goto out; 354bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 355f5b40e36SLinus Torvalds goto out; 356f5b40e36SLinus Torvalds 357f2f0b00aSOleg Nesterov /* 358f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 35986b6c1f3SDenys Vlasenko * SUID, SGID and LSM creds get determined differently 3605e751e99SDavid Howells * under ptrace. 361d84f4f99SDavid Howells */ 362793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 3639b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 364d84f4f99SDavid Howells goto out; 3654b105cbbSOleg Nesterov 366f5b40e36SLinus Torvalds task_lock(task); 367caaee623SJann Horn retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); 3684b105cbbSOleg Nesterov task_unlock(task); 3691da177e4SLinus Torvalds if (retval) 3704b105cbbSOleg Nesterov goto unlock_creds; 3711da177e4SLinus Torvalds 3724b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 373b79b7ba9SOleg Nesterov retval = -EPERM; 374b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 3754b105cbbSOleg Nesterov goto unlock_tasklist; 376f2f0b00aSOleg Nesterov if (task->ptrace) 3774b105cbbSOleg Nesterov goto unlock_tasklist; 378b79b7ba9SOleg Nesterov 3793544d72aSTejun Heo if (seize) 380aa9147c9SDenys Vlasenko flags |= PT_SEIZED; 381aa9147c9SDenys Vlasenko task->ptrace = flags; 3821da177e4SLinus Torvalds 3831da177e4SLinus Torvalds __ptrace_link(task, current); 3843544d72aSTejun Heo 3853544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 3863544d72aSTejun Heo if (!seize) 38733e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 388b79b7ba9SOleg Nesterov 389d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 390d79fdd6dSTejun Heo 391d79fdd6dSTejun Heo /* 39273ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 393d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 394d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 395d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 396d79fdd6dSTejun Heo * for the transition to complete before returning from this 397d79fdd6dSTejun Heo * function. 398d79fdd6dSTejun Heo * 399d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 400d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 401d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 402d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 403d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 404d79fdd6dSTejun Heo * 405d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 406d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 407d79fdd6dSTejun Heo */ 4087dd3db54STejun Heo if (task_is_stopped(task) && 40973ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 410910ffdb1SOleg Nesterov signal_wake_up_state(task, __TASK_STOPPED); 411d79fdd6dSTejun Heo 412d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 413d79fdd6dSTejun Heo 414b79b7ba9SOleg Nesterov retval = 0; 4154b105cbbSOleg Nesterov unlock_tasklist: 4164b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 4174b105cbbSOleg Nesterov unlock_creds: 4189b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 419f5b40e36SLinus Torvalds out: 420f701e5b7SVladimir Zapolskiy if (!retval) { 4217c3b00e0SOleg Nesterov /* 4227c3b00e0SOleg Nesterov * We do not bother to change retval or clear JOBCTL_TRAPPING 4237c3b00e0SOleg Nesterov * if wait_on_bit() was interrupted by SIGKILL. The tracer will 4247c3b00e0SOleg Nesterov * not return to user-mode, it will exit and clear this bit in 4257c3b00e0SOleg Nesterov * __ptrace_unlink() if it wasn't already cleared by the tracee; 4267c3b00e0SOleg Nesterov * and until then nobody can ptrace this task. 4277c3b00e0SOleg Nesterov */ 4287c3b00e0SOleg Nesterov wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); 429f701e5b7SVladimir Zapolskiy proc_ptrace_connector(task, PTRACE_ATTACH); 430f701e5b7SVladimir Zapolskiy } 431f701e5b7SVladimir Zapolskiy 4321da177e4SLinus Torvalds return retval; 4331da177e4SLinus Torvalds } 4341da177e4SLinus Torvalds 435f2f0b00aSOleg Nesterov /** 436f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 437f2f0b00aSOleg Nesterov * 438f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 439f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 440f2f0b00aSOleg Nesterov */ 441e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 442f2f0b00aSOleg Nesterov { 443f2f0b00aSOleg Nesterov int ret = -EPERM; 444f2f0b00aSOleg Nesterov 4454b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 4464b105cbbSOleg Nesterov /* Are we already being traced? */ 447f2f0b00aSOleg Nesterov if (!current->ptrace) { 448f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 449f2f0b00aSOleg Nesterov /* 450f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 451f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 452f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 453f2f0b00aSOleg Nesterov */ 454f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 455f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 456f2f0b00aSOleg Nesterov __ptrace_link(current, current->real_parent); 457f2f0b00aSOleg Nesterov } 458f2f0b00aSOleg Nesterov } 4594b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 4604b105cbbSOleg Nesterov 461f2f0b00aSOleg Nesterov return ret; 462f2f0b00aSOleg Nesterov } 463f2f0b00aSOleg Nesterov 46439c626aeSOleg Nesterov /* 46539c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 46639c626aeSOleg Nesterov */ 46739c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 46839c626aeSOleg Nesterov { 46939c626aeSOleg Nesterov int ret; 47039c626aeSOleg Nesterov spin_lock(&sigh->siglock); 47139c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 47239c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 47339c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 47439c626aeSOleg Nesterov return ret; 47539c626aeSOleg Nesterov } 47639c626aeSOleg Nesterov 47739c626aeSOleg Nesterov /* 47839c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 47939c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 48039c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 48139c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 48239c626aeSOleg Nesterov * 48339c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 48439c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 48539c626aeSOleg Nesterov * If it should reap itself, return true. 48639c626aeSOleg Nesterov * 487a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 488a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 489a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 490a7f0765eSOleg Nesterov * do_wait(). 49139c626aeSOleg Nesterov */ 49239c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 49339c626aeSOleg Nesterov { 4949843a1e9SOleg Nesterov bool dead; 4959843a1e9SOleg Nesterov 49639c626aeSOleg Nesterov __ptrace_unlink(p); 49739c626aeSOleg Nesterov 4989843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 4999843a1e9SOleg Nesterov return false; 5009843a1e9SOleg Nesterov 5019843a1e9SOleg Nesterov dead = !thread_group_leader(p); 5029843a1e9SOleg Nesterov 5039843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 50439c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 5059843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 506a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 507a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 5089843a1e9SOleg Nesterov dead = true; 50939c626aeSOleg Nesterov } 510a7f0765eSOleg Nesterov } 51139c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 5129843a1e9SOleg Nesterov if (dead) 51339c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 5149843a1e9SOleg Nesterov return dead; 51539c626aeSOleg Nesterov } 51639c626aeSOleg Nesterov 517e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 5181da177e4SLinus Torvalds { 5197ed20e1aSJesper Juhl if (!valid_signal(data)) 5201da177e4SLinus Torvalds return -EIO; 5211da177e4SLinus Torvalds 5221da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 5231da177e4SLinus Torvalds ptrace_disable(child); 5241da177e4SLinus Torvalds 52595c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 52639c626aeSOleg Nesterov /* 52764a4096cSOleg Nesterov * We rely on ptrace_freeze_traced(). It can't be killed and 52864a4096cSOleg Nesterov * untraced by another thread, it can't be a zombie. 52939c626aeSOleg Nesterov */ 53064a4096cSOleg Nesterov WARN_ON(!child->ptrace || child->exit_state); 53164a4096cSOleg Nesterov /* 53264a4096cSOleg Nesterov * tasklist_lock avoids the race with wait_task_stopped(), see 53364a4096cSOleg Nesterov * the comment in ptrace_resume(). 53464a4096cSOleg Nesterov */ 53595c3eb76SOleg Nesterov child->exit_code = data; 53664a4096cSOleg Nesterov __ptrace_detach(current, child); 5371da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 5381da177e4SLinus Torvalds 539f701e5b7SVladimir Zapolskiy proc_ptrace_connector(child, PTRACE_DETACH); 5404576145cSOleg Nesterov 5411da177e4SLinus Torvalds return 0; 5421da177e4SLinus Torvalds } 5431da177e4SLinus Torvalds 54439c626aeSOleg Nesterov /* 545c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 5467c8bd232SOleg Nesterov * for writing. 54739c626aeSOleg Nesterov */ 5487c8bd232SOleg Nesterov void exit_ptrace(struct task_struct *tracer, struct list_head *dead) 54939c626aeSOleg Nesterov { 55039c626aeSOleg Nesterov struct task_struct *p, *n; 551c7e49c14SOleg Nesterov 55239c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 553992fb6e1SOleg Nesterov if (unlikely(p->ptrace & PT_EXITKILL)) 554992fb6e1SOleg Nesterov send_sig_info(SIGKILL, SEND_SIG_FORCED, p); 555992fb6e1SOleg Nesterov 55639c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 5577c8bd232SOleg Nesterov list_add(&p->ptrace_entry, dead); 55839c626aeSOleg Nesterov } 55939c626aeSOleg Nesterov } 56039c626aeSOleg Nesterov 5611da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 5621da177e4SLinus Torvalds { 5631da177e4SLinus Torvalds int copied = 0; 5641da177e4SLinus Torvalds 5651da177e4SLinus Torvalds while (len > 0) { 5661da177e4SLinus Torvalds char buf[128]; 5671da177e4SLinus Torvalds int this_len, retval; 5681da177e4SLinus Torvalds 5691da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 57084d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE); 57184d77d3fSEric W. Biederman 5721da177e4SLinus Torvalds if (!retval) { 5731da177e4SLinus Torvalds if (copied) 5741da177e4SLinus Torvalds break; 5751da177e4SLinus Torvalds return -EIO; 5761da177e4SLinus Torvalds } 5771da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 5781da177e4SLinus Torvalds return -EFAULT; 5791da177e4SLinus Torvalds copied += retval; 5801da177e4SLinus Torvalds src += retval; 5811da177e4SLinus Torvalds dst += retval; 5821da177e4SLinus Torvalds len -= retval; 5831da177e4SLinus Torvalds } 5841da177e4SLinus Torvalds return copied; 5851da177e4SLinus Torvalds } 5861da177e4SLinus Torvalds 5871da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long 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; 5961da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 5971da177e4SLinus Torvalds return -EFAULT; 59884d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, dst, buf, this_len, 599f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 6001da177e4SLinus Torvalds if (!retval) { 6011da177e4SLinus Torvalds if (copied) 6021da177e4SLinus Torvalds break; 6031da177e4SLinus Torvalds return -EIO; 6041da177e4SLinus Torvalds } 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 6134abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 6141da177e4SLinus Torvalds { 61586b6c1f3SDenys Vlasenko unsigned flags; 61686b6c1f3SDenys Vlasenko 6178c5cf9e5SDenys Vlasenko if (data & ~(unsigned long)PTRACE_O_MASK) 6188c5cf9e5SDenys Vlasenko return -EINVAL; 6198c5cf9e5SDenys Vlasenko 62013c4a901STycho Andersen if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { 62197f2645fSMasahiro Yamada if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || 62297f2645fSMasahiro Yamada !IS_ENABLED(CONFIG_SECCOMP)) 62313c4a901STycho Andersen return -EINVAL; 62413c4a901STycho Andersen 62513c4a901STycho Andersen if (!capable(CAP_SYS_ADMIN)) 62613c4a901STycho Andersen return -EPERM; 62713c4a901STycho Andersen 62813c4a901STycho Andersen if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || 62913c4a901STycho Andersen current->ptrace & PT_SUSPEND_SECCOMP) 63013c4a901STycho Andersen return -EPERM; 63113c4a901STycho Andersen } 63213c4a901STycho Andersen 63386b6c1f3SDenys Vlasenko /* Avoid intermediate state when all opts are cleared */ 63486b6c1f3SDenys Vlasenko flags = child->ptrace; 63586b6c1f3SDenys Vlasenko flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); 63686b6c1f3SDenys Vlasenko flags |= (data << PT_OPT_FLAG_SHIFT); 63786b6c1f3SDenys Vlasenko child->ptrace = flags; 6381da177e4SLinus Torvalds 6398c5cf9e5SDenys Vlasenko return 0; 6401da177e4SLinus Torvalds } 6411da177e4SLinus Torvalds 642e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 6431da177e4SLinus Torvalds { 644e4961254SOleg Nesterov unsigned long flags; 6451da177e4SLinus Torvalds int error = -ESRCH; 6461da177e4SLinus Torvalds 647e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 6481da177e4SLinus Torvalds error = -EINVAL; 6491da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 650e16b2781SRoland McGrath *info = *child->last_siginfo; 6511da177e4SLinus Torvalds error = 0; 6521da177e4SLinus Torvalds } 653e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 6541da177e4SLinus Torvalds } 6551da177e4SLinus Torvalds return error; 6561da177e4SLinus Torvalds } 6571da177e4SLinus Torvalds 658e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 6591da177e4SLinus Torvalds { 660e4961254SOleg Nesterov unsigned long flags; 6611da177e4SLinus Torvalds int error = -ESRCH; 6621da177e4SLinus Torvalds 663e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 6641da177e4SLinus Torvalds error = -EINVAL; 6651da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 666e16b2781SRoland McGrath *child->last_siginfo = *info; 6671da177e4SLinus Torvalds error = 0; 6681da177e4SLinus Torvalds } 669e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 6701da177e4SLinus Torvalds } 6711da177e4SLinus Torvalds return error; 6721da177e4SLinus Torvalds } 6731da177e4SLinus Torvalds 67484c751bdSAndrey Vagin static int ptrace_peek_siginfo(struct task_struct *child, 67584c751bdSAndrey Vagin unsigned long addr, 67684c751bdSAndrey Vagin unsigned long data) 67784c751bdSAndrey Vagin { 67884c751bdSAndrey Vagin struct ptrace_peeksiginfo_args arg; 67984c751bdSAndrey Vagin struct sigpending *pending; 68084c751bdSAndrey Vagin struct sigqueue *q; 68184c751bdSAndrey Vagin int ret, i; 68284c751bdSAndrey Vagin 68384c751bdSAndrey Vagin ret = copy_from_user(&arg, (void __user *) addr, 68484c751bdSAndrey Vagin sizeof(struct ptrace_peeksiginfo_args)); 68584c751bdSAndrey Vagin if (ret) 68684c751bdSAndrey Vagin return -EFAULT; 68784c751bdSAndrey Vagin 68884c751bdSAndrey Vagin if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) 68984c751bdSAndrey Vagin return -EINVAL; /* unknown flags */ 69084c751bdSAndrey Vagin 69184c751bdSAndrey Vagin if (arg.nr < 0) 69284c751bdSAndrey Vagin return -EINVAL; 69384c751bdSAndrey Vagin 69484c751bdSAndrey Vagin if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) 69584c751bdSAndrey Vagin pending = &child->signal->shared_pending; 69684c751bdSAndrey Vagin else 69784c751bdSAndrey Vagin pending = &child->pending; 69884c751bdSAndrey Vagin 69984c751bdSAndrey Vagin for (i = 0; i < arg.nr; ) { 70084c751bdSAndrey Vagin siginfo_t info; 70184c751bdSAndrey Vagin s32 off = arg.off + i; 70284c751bdSAndrey Vagin 70384c751bdSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 70484c751bdSAndrey Vagin list_for_each_entry(q, &pending->list, list) { 70584c751bdSAndrey Vagin if (!off--) { 70684c751bdSAndrey Vagin copy_siginfo(&info, &q->info); 70784c751bdSAndrey Vagin break; 70884c751bdSAndrey Vagin } 70984c751bdSAndrey Vagin } 71084c751bdSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 71184c751bdSAndrey Vagin 71284c751bdSAndrey Vagin if (off >= 0) /* beyond the end of the list */ 71384c751bdSAndrey Vagin break; 71484c751bdSAndrey Vagin 71584c751bdSAndrey Vagin #ifdef CONFIG_COMPAT 7165c465217SAndy Lutomirski if (unlikely(in_compat_syscall())) { 71784c751bdSAndrey Vagin compat_siginfo_t __user *uinfo = compat_ptr(data); 71884c751bdSAndrey Vagin 719706b23bdSMathieu Desnoyers if (copy_siginfo_to_user32(uinfo, &info) || 720706b23bdSMathieu Desnoyers __put_user(info.si_code, &uinfo->si_code)) { 721706b23bdSMathieu Desnoyers ret = -EFAULT; 722706b23bdSMathieu Desnoyers break; 723706b23bdSMathieu Desnoyers } 724706b23bdSMathieu Desnoyers 72584c751bdSAndrey Vagin } else 72684c751bdSAndrey Vagin #endif 72784c751bdSAndrey Vagin { 72884c751bdSAndrey Vagin siginfo_t __user *uinfo = (siginfo_t __user *) data; 72984c751bdSAndrey Vagin 730706b23bdSMathieu Desnoyers if (copy_siginfo_to_user(uinfo, &info) || 731706b23bdSMathieu Desnoyers __put_user(info.si_code, &uinfo->si_code)) { 73284c751bdSAndrey Vagin ret = -EFAULT; 73384c751bdSAndrey Vagin break; 73484c751bdSAndrey Vagin } 735706b23bdSMathieu Desnoyers } 73684c751bdSAndrey Vagin 73784c751bdSAndrey Vagin data += sizeof(siginfo_t); 73884c751bdSAndrey Vagin i++; 73984c751bdSAndrey Vagin 74084c751bdSAndrey Vagin if (signal_pending(current)) 74184c751bdSAndrey Vagin break; 74284c751bdSAndrey Vagin 74384c751bdSAndrey Vagin cond_resched(); 74484c751bdSAndrey Vagin } 74584c751bdSAndrey Vagin 74684c751bdSAndrey Vagin if (i > 0) 74784c751bdSAndrey Vagin return i; 74884c751bdSAndrey Vagin 74984c751bdSAndrey Vagin return ret; 75084c751bdSAndrey Vagin } 75136df29d7SRoland McGrath 75236df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 75336df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 75436df29d7SRoland McGrath #else 75536df29d7SRoland McGrath #define is_singlestep(request) 0 75636df29d7SRoland McGrath #endif 75736df29d7SRoland McGrath 7585b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 7595b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 7605b88abbfSRoland McGrath #else 7615b88abbfSRoland McGrath #define is_singleblock(request) 0 7625b88abbfSRoland McGrath #endif 7635b88abbfSRoland McGrath 76436df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 76536df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 76636df29d7SRoland McGrath #else 76736df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 76836df29d7SRoland McGrath #endif 76936df29d7SRoland McGrath 7704abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 7714abf9869SNamhyung Kim unsigned long data) 77236df29d7SRoland McGrath { 773b72c1869SOleg Nesterov bool need_siglock; 774b72c1869SOleg Nesterov 77536df29d7SRoland McGrath if (!valid_signal(data)) 77636df29d7SRoland McGrath return -EIO; 77736df29d7SRoland McGrath 77836df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 77936df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 78036df29d7SRoland McGrath else 78136df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 78236df29d7SRoland McGrath 78336df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 78436df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 78536df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 78636df29d7SRoland McGrath else 78736df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 78836df29d7SRoland McGrath #endif 78936df29d7SRoland McGrath 7905b88abbfSRoland McGrath if (is_singleblock(request)) { 7915b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 7925b88abbfSRoland McGrath return -EIO; 7935b88abbfSRoland McGrath user_enable_block_step(child); 7945b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 79536df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 79636df29d7SRoland McGrath return -EIO; 79736df29d7SRoland McGrath user_enable_single_step(child); 7983a709703SRoland McGrath } else { 79936df29d7SRoland McGrath user_disable_single_step(child); 8003a709703SRoland McGrath } 80136df29d7SRoland McGrath 802b72c1869SOleg Nesterov /* 803b72c1869SOleg Nesterov * Change ->exit_code and ->state under siglock to avoid the race 804b72c1869SOleg Nesterov * with wait_task_stopped() in between; a non-zero ->exit_code will 805b72c1869SOleg Nesterov * wrongly look like another report from tracee. 806b72c1869SOleg Nesterov * 807b72c1869SOleg Nesterov * Note that we need siglock even if ->exit_code == data and/or this 808b72c1869SOleg Nesterov * status was not reported yet, the new status must not be cleared by 809b72c1869SOleg Nesterov * wait_task_stopped() after resume. 810b72c1869SOleg Nesterov * 811b72c1869SOleg Nesterov * If data == 0 we do not care if wait_task_stopped() reports the old 812b72c1869SOleg Nesterov * status and clears the code too; this can't race with the tracee, it 813b72c1869SOleg Nesterov * takes siglock after resume. 814b72c1869SOleg Nesterov */ 815b72c1869SOleg Nesterov need_siglock = data && !thread_group_empty(current); 816b72c1869SOleg Nesterov if (need_siglock) 817b72c1869SOleg Nesterov spin_lock_irq(&child->sighand->siglock); 81836df29d7SRoland McGrath child->exit_code = data; 8190666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 820b72c1869SOleg Nesterov if (need_siglock) 821b72c1869SOleg Nesterov spin_unlock_irq(&child->sighand->siglock); 82236df29d7SRoland McGrath 82336df29d7SRoland McGrath return 0; 82436df29d7SRoland McGrath } 82536df29d7SRoland McGrath 8262225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8272225a122SSuresh Siddha 8282225a122SSuresh Siddha static const struct user_regset * 8292225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 8302225a122SSuresh Siddha { 8312225a122SSuresh Siddha const struct user_regset *regset; 8322225a122SSuresh Siddha int n; 8332225a122SSuresh Siddha 8342225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 8352225a122SSuresh Siddha regset = view->regsets + n; 8362225a122SSuresh Siddha if (regset->core_note_type == type) 8372225a122SSuresh Siddha return regset; 8382225a122SSuresh Siddha } 8392225a122SSuresh Siddha 8402225a122SSuresh Siddha return NULL; 8412225a122SSuresh Siddha } 8422225a122SSuresh Siddha 8432225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 8442225a122SSuresh Siddha struct iovec *kiov) 8452225a122SSuresh Siddha { 8462225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 8472225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 8482225a122SSuresh Siddha int regset_no; 8492225a122SSuresh Siddha 8502225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 851c6a0dd7eSSuresh Siddha return -EINVAL; 8522225a122SSuresh Siddha 8532225a122SSuresh Siddha regset_no = regset - view->regsets; 8542225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 8552225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 8562225a122SSuresh Siddha 8572225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 8582225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 8592225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 8602225a122SSuresh Siddha else 8612225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 8622225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 8632225a122SSuresh Siddha } 8642225a122SSuresh Siddha 865e8440c14SJosh Stone /* 866e8440c14SJosh Stone * This is declared in linux/regset.h and defined in machine-dependent 867e8440c14SJosh Stone * code. We put the export here, near the primary machine-neutral use, 868e8440c14SJosh Stone * to ensure no machine forgets it. 869e8440c14SJosh Stone */ 870e8440c14SJosh Stone EXPORT_SYMBOL_GPL(task_user_regset_view); 8712225a122SSuresh Siddha #endif 8722225a122SSuresh Siddha 8731da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 8744abf9869SNamhyung Kim unsigned long addr, unsigned long data) 8751da177e4SLinus Torvalds { 876fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 8771da177e4SLinus Torvalds int ret = -EIO; 878544b2c91STejun Heo siginfo_t siginfo, *si; 8799fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 8809fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 881fca26f26STejun Heo unsigned long flags; 8821da177e4SLinus Torvalds 8831da177e4SLinus Torvalds switch (request) { 88416c3e389SRoland McGrath case PTRACE_PEEKTEXT: 88516c3e389SRoland McGrath case PTRACE_PEEKDATA: 88616c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 88716c3e389SRoland McGrath case PTRACE_POKETEXT: 88816c3e389SRoland McGrath case PTRACE_POKEDATA: 88916c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 89016c3e389SRoland McGrath 8911da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 8921da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 8931da177e4SLinus Torvalds #endif 8941da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 8951da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 8961da177e4SLinus Torvalds break; 8971da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 8989fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 8991da177e4SLinus Torvalds break; 900e16b2781SRoland McGrath 90184c751bdSAndrey Vagin case PTRACE_PEEKSIGINFO: 90284c751bdSAndrey Vagin ret = ptrace_peek_siginfo(child, addr, data); 90384c751bdSAndrey Vagin break; 90484c751bdSAndrey Vagin 9051da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 906e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 907e16b2781SRoland McGrath if (!ret) 9089fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 9091da177e4SLinus Torvalds break; 910e16b2781SRoland McGrath 9111da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 9129fed81dcSNamhyung Kim if (copy_from_user(&siginfo, datavp, sizeof siginfo)) 913e16b2781SRoland McGrath ret = -EFAULT; 914e16b2781SRoland McGrath else 915e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 9161da177e4SLinus Torvalds break; 917e16b2781SRoland McGrath 91829000caeSAndrey Vagin case PTRACE_GETSIGMASK: 91929000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 92029000caeSAndrey Vagin ret = -EINVAL; 92129000caeSAndrey Vagin break; 92229000caeSAndrey Vagin } 92329000caeSAndrey Vagin 92429000caeSAndrey Vagin if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t))) 92529000caeSAndrey Vagin ret = -EFAULT; 92629000caeSAndrey Vagin else 92729000caeSAndrey Vagin ret = 0; 92829000caeSAndrey Vagin 92929000caeSAndrey Vagin break; 93029000caeSAndrey Vagin 93129000caeSAndrey Vagin case PTRACE_SETSIGMASK: { 93229000caeSAndrey Vagin sigset_t new_set; 93329000caeSAndrey Vagin 93429000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 93529000caeSAndrey Vagin ret = -EINVAL; 93629000caeSAndrey Vagin break; 93729000caeSAndrey Vagin } 93829000caeSAndrey Vagin 93929000caeSAndrey Vagin if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { 94029000caeSAndrey Vagin ret = -EFAULT; 94129000caeSAndrey Vagin break; 94229000caeSAndrey Vagin } 94329000caeSAndrey Vagin 94429000caeSAndrey Vagin sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); 94529000caeSAndrey Vagin 94629000caeSAndrey Vagin /* 94729000caeSAndrey Vagin * Every thread does recalc_sigpending() after resume, so 94829000caeSAndrey Vagin * retarget_shared_pending() and recalc_sigpending() are not 94929000caeSAndrey Vagin * called here. 95029000caeSAndrey Vagin */ 95129000caeSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 95229000caeSAndrey Vagin child->blocked = new_set; 95329000caeSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 95429000caeSAndrey Vagin 95529000caeSAndrey Vagin ret = 0; 95629000caeSAndrey Vagin break; 95729000caeSAndrey Vagin } 95829000caeSAndrey Vagin 959fca26f26STejun Heo case PTRACE_INTERRUPT: 960fca26f26STejun Heo /* 961fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 962fca26f26STejun Heo * control. At least one trap is guaranteed to happen 963fca26f26STejun Heo * after this request. If @child is already trapped, the 964fca26f26STejun Heo * current trap is not disturbed and another trap will 965fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 966fca26f26STejun Heo * 967fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 968fca26f26STejun Heo * the pending condition is cleared regardless. 969fca26f26STejun Heo */ 970fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 971fca26f26STejun Heo break; 972fca26f26STejun Heo 973544b2c91STejun Heo /* 974544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 975544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 976544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 977544b2c91STejun Heo * tracee into STOP. 978544b2c91STejun Heo */ 979fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 980910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 981544b2c91STejun Heo 982544b2c91STejun Heo unlock_task_sighand(child, &flags); 983544b2c91STejun Heo ret = 0; 984544b2c91STejun Heo break; 985544b2c91STejun Heo 986544b2c91STejun Heo case PTRACE_LISTEN: 987544b2c91STejun Heo /* 988544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 989544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 990544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 991544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 992544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 993544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 994544b2c91STejun Heo */ 995544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 996544b2c91STejun Heo break; 997544b2c91STejun Heo 998544b2c91STejun Heo si = child->last_siginfo; 999f9d81f61SOleg Nesterov if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { 1000544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 1001544b2c91STejun Heo /* 1002f9d81f61SOleg Nesterov * If NOTIFY is set, it means event happened between 1003f9d81f61SOleg Nesterov * start of this trap and now. Trigger re-trap. 1004544b2c91STejun Heo */ 1005544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 1006910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 1007fca26f26STejun Heo ret = 0; 1008f9d81f61SOleg Nesterov } 1009f9d81f61SOleg Nesterov unlock_task_sighand(child, &flags); 1010fca26f26STejun Heo break; 1011fca26f26STejun Heo 10121bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 10131bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 10141bcf5482SAlexey Dobriyan break; 101536df29d7SRoland McGrath 10169c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 10179c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 1018e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 10199c1a1259SMike Frysinger unsigned long tmp = 0; 10209c1a1259SMike Frysinger 1021e0129ef9SOleg Nesterov ret = -ESRCH; 1022e0129ef9SOleg Nesterov if (!mm) 1023e0129ef9SOleg Nesterov break; 1024e0129ef9SOleg Nesterov 10259c1a1259SMike Frysinger switch (addr) { 10269c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 1027e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 10289c1a1259SMike Frysinger break; 10299c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 1030e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 10319c1a1259SMike Frysinger break; 10329c1a1259SMike Frysinger default: 10339c1a1259SMike Frysinger break; 10349c1a1259SMike Frysinger } 1035e0129ef9SOleg Nesterov mmput(mm); 10369c1a1259SMike Frysinger 10379fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 10389c1a1259SMike Frysinger break; 10399c1a1259SMike Frysinger } 10409c1a1259SMike Frysinger #endif 10419c1a1259SMike Frysinger 104236df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 104336df29d7SRoland McGrath case PTRACE_SINGLESTEP: 104436df29d7SRoland McGrath #endif 10455b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 10465b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 10475b88abbfSRoland McGrath #endif 104836df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 104936df29d7SRoland McGrath case PTRACE_SYSEMU: 105036df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 105136df29d7SRoland McGrath #endif 105236df29d7SRoland McGrath case PTRACE_SYSCALL: 105336df29d7SRoland McGrath case PTRACE_CONT: 105436df29d7SRoland McGrath return ptrace_resume(child, request, data); 105536df29d7SRoland McGrath 105636df29d7SRoland McGrath case PTRACE_KILL: 105736df29d7SRoland McGrath if (child->exit_state) /* already dead */ 105836df29d7SRoland McGrath return 0; 105936df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 106036df29d7SRoland McGrath 10612225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 10622225a122SSuresh Siddha case PTRACE_GETREGSET: 106329000caeSAndrey Vagin case PTRACE_SETREGSET: { 10642225a122SSuresh Siddha struct iovec kiov; 10659fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 10662225a122SSuresh Siddha 10672225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 10682225a122SSuresh Siddha return -EFAULT; 10692225a122SSuresh Siddha 10702225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 10712225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 10722225a122SSuresh Siddha return -EFAULT; 10732225a122SSuresh Siddha 10742225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 10752225a122SSuresh Siddha if (!ret) 10762225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 10772225a122SSuresh Siddha break; 10782225a122SSuresh Siddha } 10792225a122SSuresh Siddha #endif 1080f8e529edSTycho Andersen 1081f8e529edSTycho Andersen case PTRACE_SECCOMP_GET_FILTER: 1082f8e529edSTycho Andersen ret = seccomp_get_filter(child, addr, datavp); 1083f8e529edSTycho Andersen break; 1084f8e529edSTycho Andersen 10851da177e4SLinus Torvalds default: 10861da177e4SLinus Torvalds break; 10871da177e4SLinus Torvalds } 10881da177e4SLinus Torvalds 10891da177e4SLinus Torvalds return ret; 10901da177e4SLinus Torvalds } 1091481bed45SChristoph Hellwig 10928053bdd5SOleg Nesterov static struct task_struct *ptrace_get_task_struct(pid_t pid) 10936b9c7ed8SChristoph Hellwig { 10946b9c7ed8SChristoph Hellwig struct task_struct *child; 10956b9c7ed8SChristoph Hellwig 10968053bdd5SOleg Nesterov rcu_read_lock(); 1097228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 1098481bed45SChristoph Hellwig if (child) 1099481bed45SChristoph Hellwig get_task_struct(child); 11008053bdd5SOleg Nesterov rcu_read_unlock(); 1101f400e198SSukadev Bhattiprolu 1102481bed45SChristoph Hellwig if (!child) 11036b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 11046b9c7ed8SChristoph Hellwig return child; 1105481bed45SChristoph Hellwig } 1106481bed45SChristoph Hellwig 11070ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 11080ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 11090ac15559SChristoph Hellwig #endif 11100ac15559SChristoph Hellwig 11114abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 11124abf9869SNamhyung Kim unsigned long, data) 1113481bed45SChristoph Hellwig { 1114481bed45SChristoph Hellwig struct task_struct *child; 1115481bed45SChristoph Hellwig long ret; 1116481bed45SChristoph Hellwig 11176b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 11186b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 11196ea6dd93SHaavard Skinnemoen if (!ret) 11206ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 1121481bed45SChristoph Hellwig goto out; 11226b9c7ed8SChristoph Hellwig } 11236b9c7ed8SChristoph Hellwig 11246b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 11256b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 11266b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 11276b9c7ed8SChristoph Hellwig goto out; 11286b9c7ed8SChristoph Hellwig } 1129481bed45SChristoph Hellwig 11303544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1131aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 11320ac15559SChristoph Hellwig /* 11330ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 11340ac15559SChristoph Hellwig * a ptrace attach. 11350ac15559SChristoph Hellwig */ 11360ac15559SChristoph Hellwig if (!ret) 11370ac15559SChristoph Hellwig arch_ptrace_attach(child); 1138005f18dfSChristoph Hellwig goto out_put_task_struct; 1139481bed45SChristoph Hellwig } 1140481bed45SChristoph Hellwig 1141fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1142fca26f26STejun Heo request == PTRACE_INTERRUPT); 1143481bed45SChristoph Hellwig if (ret < 0) 1144481bed45SChristoph Hellwig goto out_put_task_struct; 1145481bed45SChristoph Hellwig 1146481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 11479899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 11489899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 1149481bed45SChristoph Hellwig 1150481bed45SChristoph Hellwig out_put_task_struct: 1151481bed45SChristoph Hellwig put_task_struct(child); 1152481bed45SChristoph Hellwig out: 1153481bed45SChristoph Hellwig return ret; 1154481bed45SChristoph Hellwig } 115576647323SAlexey Dobriyan 11564abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 11574abf9869SNamhyung Kim unsigned long data) 115876647323SAlexey Dobriyan { 115976647323SAlexey Dobriyan unsigned long tmp; 116076647323SAlexey Dobriyan int copied; 116176647323SAlexey Dobriyan 116284d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); 116376647323SAlexey Dobriyan if (copied != sizeof(tmp)) 116476647323SAlexey Dobriyan return -EIO; 116576647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 116676647323SAlexey Dobriyan } 1167f284ce72SAlexey Dobriyan 11684abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 11694abf9869SNamhyung Kim unsigned long data) 1170f284ce72SAlexey Dobriyan { 1171f284ce72SAlexey Dobriyan int copied; 1172f284ce72SAlexey Dobriyan 117384d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &data, sizeof(data), 1174f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1175f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 1176f284ce72SAlexey Dobriyan } 1177032d82d9SRoland McGrath 117896b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 1179032d82d9SRoland McGrath 1180032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 1181032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 1182032d82d9SRoland McGrath { 1183032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 1184032d82d9SRoland McGrath compat_ulong_t word; 1185e16b2781SRoland McGrath siginfo_t siginfo; 1186032d82d9SRoland McGrath int ret; 1187032d82d9SRoland McGrath 1188032d82d9SRoland McGrath switch (request) { 1189032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 1190032d82d9SRoland McGrath case PTRACE_PEEKDATA: 119184d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &word, sizeof(word), 1192f307ab6dSLorenzo Stoakes FOLL_FORCE); 1193032d82d9SRoland McGrath if (ret != sizeof(word)) 1194032d82d9SRoland McGrath ret = -EIO; 1195032d82d9SRoland McGrath else 1196032d82d9SRoland McGrath ret = put_user(word, datap); 1197032d82d9SRoland McGrath break; 1198032d82d9SRoland McGrath 1199032d82d9SRoland McGrath case PTRACE_POKETEXT: 1200032d82d9SRoland McGrath case PTRACE_POKEDATA: 120184d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &data, sizeof(data), 1202f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1203032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 1204032d82d9SRoland McGrath break; 1205032d82d9SRoland McGrath 1206032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 1207032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 1208032d82d9SRoland McGrath break; 1209032d82d9SRoland McGrath 1210e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 1211e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 1212e16b2781SRoland McGrath if (!ret) 1213e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 1214e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 1215e16b2781SRoland McGrath &siginfo); 1216e16b2781SRoland McGrath break; 1217e16b2781SRoland McGrath 1218e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 1219e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 1220e16b2781SRoland McGrath if (copy_siginfo_from_user32( 1221e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 1222e16b2781SRoland McGrath ret = -EFAULT; 1223e16b2781SRoland McGrath else 1224e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 1225e16b2781SRoland McGrath break; 12262225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 12272225a122SSuresh Siddha case PTRACE_GETREGSET: 12282225a122SSuresh Siddha case PTRACE_SETREGSET: 12292225a122SSuresh Siddha { 12302225a122SSuresh Siddha struct iovec kiov; 12312225a122SSuresh Siddha struct compat_iovec __user *uiov = 12322225a122SSuresh Siddha (struct compat_iovec __user *) datap; 12332225a122SSuresh Siddha compat_uptr_t ptr; 12342225a122SSuresh Siddha compat_size_t len; 12352225a122SSuresh Siddha 12362225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 12372225a122SSuresh Siddha return -EFAULT; 12382225a122SSuresh Siddha 12392225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 12402225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 12412225a122SSuresh Siddha return -EFAULT; 12422225a122SSuresh Siddha 12432225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 12442225a122SSuresh Siddha kiov.iov_len = len; 12452225a122SSuresh Siddha 12462225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 12472225a122SSuresh Siddha if (!ret) 12482225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 12492225a122SSuresh Siddha break; 12502225a122SSuresh Siddha } 12512225a122SSuresh Siddha #endif 1252e16b2781SRoland McGrath 1253032d82d9SRoland McGrath default: 1254032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 1255032d82d9SRoland McGrath } 1256032d82d9SRoland McGrath 1257032d82d9SRoland McGrath return ret; 1258032d82d9SRoland McGrath } 1259c269f196SRoland McGrath 126062a6fa97SHeiko Carstens COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, 126162a6fa97SHeiko Carstens compat_long_t, addr, compat_long_t, data) 1262c269f196SRoland McGrath { 1263c269f196SRoland McGrath struct task_struct *child; 1264c269f196SRoland McGrath long ret; 1265c269f196SRoland McGrath 1266c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1267c269f196SRoland McGrath ret = ptrace_traceme(); 1268c269f196SRoland McGrath goto out; 1269c269f196SRoland McGrath } 1270c269f196SRoland McGrath 1271c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 1272c269f196SRoland McGrath if (IS_ERR(child)) { 1273c269f196SRoland McGrath ret = PTR_ERR(child); 1274c269f196SRoland McGrath goto out; 1275c269f196SRoland McGrath } 1276c269f196SRoland McGrath 12773544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1278aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 1279c269f196SRoland McGrath /* 1280c269f196SRoland McGrath * Some architectures need to do book-keeping after 1281c269f196SRoland McGrath * a ptrace attach. 1282c269f196SRoland McGrath */ 1283c269f196SRoland McGrath if (!ret) 1284c269f196SRoland McGrath arch_ptrace_attach(child); 1285c269f196SRoland McGrath goto out_put_task_struct; 1286c269f196SRoland McGrath } 1287c269f196SRoland McGrath 1288fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1289fca26f26STejun Heo request == PTRACE_INTERRUPT); 12909899d11fSOleg Nesterov if (!ret) { 1291c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 12929899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 12939899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 12949899d11fSOleg Nesterov } 1295c269f196SRoland McGrath 1296c269f196SRoland McGrath out_put_task_struct: 1297c269f196SRoland McGrath put_task_struct(child); 1298c269f196SRoland McGrath out: 1299c269f196SRoland McGrath return ret; 1300c269f196SRoland McGrath } 130196b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1302