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 1875402e97aSbsegall@google.com /* 1885402e97aSbsegall@google.com * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely. 1895402e97aSbsegall@google.com * Recheck state under the lock to close this race. 1905402e97aSbsegall@google.com */ 1919899d11fSOleg Nesterov spin_lock_irq(&task->sighand->siglock); 1925402e97aSbsegall@google.com if (task->state == __TASK_TRACED) { 1939899d11fSOleg Nesterov if (__fatal_signal_pending(task)) 1949899d11fSOleg Nesterov wake_up_state(task, __TASK_TRACED); 1959899d11fSOleg Nesterov else 1969899d11fSOleg Nesterov task->state = TASK_TRACED; 1975402e97aSbsegall@google.com } 1989899d11fSOleg Nesterov spin_unlock_irq(&task->sighand->siglock); 1999899d11fSOleg Nesterov } 2009899d11fSOleg Nesterov 201755e276bSTejun Heo /** 202755e276bSTejun Heo * ptrace_check_attach - check whether ptracee is ready for ptrace operation 203755e276bSTejun Heo * @child: ptracee to check for 204755e276bSTejun Heo * @ignore_state: don't check whether @child is currently %TASK_TRACED 205755e276bSTejun Heo * 206755e276bSTejun Heo * Check whether @child is being ptraced by %current and ready for further 207755e276bSTejun Heo * ptrace operations. If @ignore_state is %false, @child also should be in 208755e276bSTejun Heo * %TASK_TRACED state and on return the child is guaranteed to be traced 209755e276bSTejun Heo * and not executing. If @ignore_state is %true, @child can be in any 210755e276bSTejun Heo * state. 211755e276bSTejun Heo * 212755e276bSTejun Heo * CONTEXT: 213755e276bSTejun Heo * Grabs and releases tasklist_lock and @child->sighand->siglock. 214755e276bSTejun Heo * 215755e276bSTejun Heo * RETURNS: 216755e276bSTejun Heo * 0 on success, -ESRCH if %child is not ready. 2171da177e4SLinus Torvalds */ 218edea0d03SOleg Nesterov static int ptrace_check_attach(struct task_struct *child, bool ignore_state) 2191da177e4SLinus Torvalds { 2201da177e4SLinus Torvalds int ret = -ESRCH; 2211da177e4SLinus Torvalds 2221da177e4SLinus Torvalds /* 2231da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 2241da177e4SLinus Torvalds * possible race where someone else was tracing our child and 2251da177e4SLinus Torvalds * detached between these two checks. After this locked check, 2261da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 2271da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 2281da177e4SLinus Torvalds */ 2291da177e4SLinus Torvalds read_lock(&tasklist_lock); 2309899d11fSOleg Nesterov if (child->ptrace && child->parent == current) { 2319899d11fSOleg Nesterov WARN_ON(child->state == __TASK_TRACED); 232c0c0b649SOleg Nesterov /* 233c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 234c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 235c0c0b649SOleg Nesterov */ 2369899d11fSOleg Nesterov if (ignore_state || ptrace_freeze_traced(child)) 237321fb561SOleg Nesterov ret = 0; 2381da177e4SLinus Torvalds } 2391da177e4SLinus Torvalds read_unlock(&tasklist_lock); 2401da177e4SLinus Torvalds 2419899d11fSOleg Nesterov if (!ret && !ignore_state) { 2429899d11fSOleg Nesterov if (!wait_task_inactive(child, __TASK_TRACED)) { 2439899d11fSOleg Nesterov /* 2449899d11fSOleg Nesterov * This can only happen if may_ptrace_stop() fails and 2459899d11fSOleg Nesterov * ptrace_stop() changes ->state back to TASK_RUNNING, 2469899d11fSOleg Nesterov * so we should not worry about leaking __TASK_TRACED. 2479899d11fSOleg Nesterov */ 2489899d11fSOleg Nesterov WARN_ON(child->state == __TASK_TRACED); 2499899d11fSOleg Nesterov ret = -ESRCH; 2509899d11fSOleg Nesterov } 2519899d11fSOleg Nesterov } 2521da177e4SLinus Torvalds 2531da177e4SLinus Torvalds return ret; 2541da177e4SLinus Torvalds } 2551da177e4SLinus Torvalds 25669f594a3SEric Paris static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) 25769f594a3SEric Paris { 25869f594a3SEric Paris if (mode & PTRACE_MODE_NOAUDIT) 25969f594a3SEric Paris return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); 26069f594a3SEric Paris else 26169f594a3SEric Paris return has_ns_capability(current, ns, CAP_SYS_PTRACE); 26269f594a3SEric Paris } 26369f594a3SEric Paris 2649f99798fSTetsuo Handa /* Returns 0 on success, -errno on denial. */ 2659f99798fSTetsuo Handa static int __ptrace_may_access(struct task_struct *task, unsigned int mode) 266ab8d11beSMiklos Szeredi { 267c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 268bfedb589SEric W. Biederman struct mm_struct *mm; 269caaee623SJann Horn kuid_t caller_uid; 270caaee623SJann Horn kgid_t caller_gid; 271caaee623SJann Horn 272caaee623SJann Horn if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { 273caaee623SJann Horn WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); 274caaee623SJann Horn return -EPERM; 275caaee623SJann Horn } 276b6dff3ecSDavid Howells 277df26c40eSEric W. Biederman /* May we inspect the given task? 278df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 279df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 280df26c40eSEric W. Biederman * 281df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 282df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 283df26c40eSEric W. Biederman * or halting the specified task is impossible. 284df26c40eSEric W. Biederman */ 285caaee623SJann Horn 286df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 28773af963fSMark Grondona if (same_thread_group(task, current)) 288df26c40eSEric W. Biederman return 0; 289c69e8d9cSDavid Howells rcu_read_lock(); 290caaee623SJann Horn if (mode & PTRACE_MODE_FSCREDS) { 291caaee623SJann Horn caller_uid = cred->fsuid; 292caaee623SJann Horn caller_gid = cred->fsgid; 293caaee623SJann Horn } else { 294caaee623SJann Horn /* 295caaee623SJann Horn * Using the euid would make more sense here, but something 296caaee623SJann Horn * in userland might rely on the old behavior, and this 297caaee623SJann Horn * shouldn't be a security problem since 298caaee623SJann Horn * PTRACE_MODE_REALCREDS implies that the caller explicitly 299caaee623SJann Horn * used a syscall that requests access to another process 300caaee623SJann Horn * (and not a filesystem syscall to procfs). 301caaee623SJann Horn */ 302caaee623SJann Horn caller_uid = cred->uid; 303caaee623SJann Horn caller_gid = cred->gid; 304caaee623SJann Horn } 305c69e8d9cSDavid Howells tcred = __task_cred(task); 306caaee623SJann Horn if (uid_eq(caller_uid, tcred->euid) && 307caaee623SJann Horn uid_eq(caller_uid, tcred->suid) && 308caaee623SJann Horn uid_eq(caller_uid, tcred->uid) && 309caaee623SJann Horn gid_eq(caller_gid, tcred->egid) && 310caaee623SJann Horn gid_eq(caller_gid, tcred->sgid) && 311caaee623SJann Horn gid_eq(caller_gid, tcred->gid)) 3128409cca7SSerge E. Hallyn goto ok; 313c4a4d603SEric W. Biederman if (ptrace_has_cap(tcred->user_ns, mode)) 3148409cca7SSerge E. Hallyn goto ok; 315c69e8d9cSDavid Howells rcu_read_unlock(); 316ab8d11beSMiklos Szeredi return -EPERM; 3178409cca7SSerge E. Hallyn ok: 318c69e8d9cSDavid Howells rcu_read_unlock(); 319bfedb589SEric W. Biederman mm = task->mm; 320bfedb589SEric W. Biederman if (mm && 321bfedb589SEric W. Biederman ((get_dumpable(mm) != SUID_DUMP_USER) && 322bfedb589SEric W. Biederman !ptrace_has_cap(mm->user_ns, mode))) 323ab8d11beSMiklos Szeredi return -EPERM; 324ab8d11beSMiklos Szeredi 3259e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 326ab8d11beSMiklos Szeredi } 327ab8d11beSMiklos Szeredi 328006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 329ab8d11beSMiklos Szeredi { 330ab8d11beSMiklos Szeredi int err; 331ab8d11beSMiklos Szeredi task_lock(task); 332006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 333ab8d11beSMiklos Szeredi task_unlock(task); 3343a709703SRoland McGrath return !err; 335ab8d11beSMiklos Szeredi } 336ab8d11beSMiklos Szeredi 3373544d72aSTejun Heo static int ptrace_attach(struct task_struct *task, long request, 338aa9147c9SDenys Vlasenko unsigned long addr, 3393544d72aSTejun Heo unsigned long flags) 3401da177e4SLinus Torvalds { 3413544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 3421da177e4SLinus Torvalds int retval; 343f5b40e36SLinus Torvalds 3443544d72aSTejun Heo retval = -EIO; 345aa9147c9SDenys Vlasenko if (seize) { 346aa9147c9SDenys Vlasenko if (addr != 0) 3473544d72aSTejun Heo goto out; 348aa9147c9SDenys Vlasenko if (flags & ~(unsigned long)PTRACE_O_MASK) 349aa9147c9SDenys Vlasenko goto out; 350aa9147c9SDenys Vlasenko flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); 351aa9147c9SDenys Vlasenko } else { 352aa9147c9SDenys Vlasenko flags = PT_PTRACED; 353aa9147c9SDenys Vlasenko } 3543544d72aSTejun Heo 355a5cb013dSAl Viro audit_ptrace(task); 356a5cb013dSAl Viro 3571da177e4SLinus Torvalds retval = -EPERM; 358b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 359b79b7ba9SOleg Nesterov goto out; 360bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 361f5b40e36SLinus Torvalds goto out; 362f5b40e36SLinus Torvalds 363f2f0b00aSOleg Nesterov /* 364f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 36586b6c1f3SDenys Vlasenko * SUID, SGID and LSM creds get determined differently 3665e751e99SDavid Howells * under ptrace. 367d84f4f99SDavid Howells */ 368793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 3699b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 370d84f4f99SDavid Howells goto out; 3714b105cbbSOleg Nesterov 372f5b40e36SLinus Torvalds task_lock(task); 373caaee623SJann Horn retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); 3744b105cbbSOleg Nesterov task_unlock(task); 3751da177e4SLinus Torvalds if (retval) 3764b105cbbSOleg Nesterov goto unlock_creds; 3771da177e4SLinus Torvalds 3784b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 379b79b7ba9SOleg Nesterov retval = -EPERM; 380b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 3814b105cbbSOleg Nesterov goto unlock_tasklist; 382f2f0b00aSOleg Nesterov if (task->ptrace) 3834b105cbbSOleg Nesterov goto unlock_tasklist; 384b79b7ba9SOleg Nesterov 3853544d72aSTejun Heo if (seize) 386aa9147c9SDenys Vlasenko flags |= PT_SEIZED; 387aa9147c9SDenys Vlasenko task->ptrace = flags; 3881da177e4SLinus Torvalds 3891da177e4SLinus Torvalds __ptrace_link(task, current); 3903544d72aSTejun Heo 3913544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 3923544d72aSTejun Heo if (!seize) 39333e9fc7dSOleg Nesterov send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); 394b79b7ba9SOleg Nesterov 395d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 396d79fdd6dSTejun Heo 397d79fdd6dSTejun Heo /* 39873ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 399d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 400d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 401d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 402d79fdd6dSTejun Heo * for the transition to complete before returning from this 403d79fdd6dSTejun Heo * function. 404d79fdd6dSTejun Heo * 405d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 406d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 407d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 408d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 409d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 410d79fdd6dSTejun Heo * 411d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 412d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 413d79fdd6dSTejun Heo */ 4147dd3db54STejun Heo if (task_is_stopped(task) && 41573ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 416910ffdb1SOleg Nesterov signal_wake_up_state(task, __TASK_STOPPED); 417d79fdd6dSTejun Heo 418d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 419d79fdd6dSTejun Heo 420b79b7ba9SOleg Nesterov retval = 0; 4214b105cbbSOleg Nesterov unlock_tasklist: 4224b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 4234b105cbbSOleg Nesterov unlock_creds: 4249b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 425f5b40e36SLinus Torvalds out: 426f701e5b7SVladimir Zapolskiy if (!retval) { 4277c3b00e0SOleg Nesterov /* 4287c3b00e0SOleg Nesterov * We do not bother to change retval or clear JOBCTL_TRAPPING 4297c3b00e0SOleg Nesterov * if wait_on_bit() was interrupted by SIGKILL. The tracer will 4307c3b00e0SOleg Nesterov * not return to user-mode, it will exit and clear this bit in 4317c3b00e0SOleg Nesterov * __ptrace_unlink() if it wasn't already cleared by the tracee; 4327c3b00e0SOleg Nesterov * and until then nobody can ptrace this task. 4337c3b00e0SOleg Nesterov */ 4347c3b00e0SOleg Nesterov wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); 435f701e5b7SVladimir Zapolskiy proc_ptrace_connector(task, PTRACE_ATTACH); 436f701e5b7SVladimir Zapolskiy } 437f701e5b7SVladimir Zapolskiy 4381da177e4SLinus Torvalds return retval; 4391da177e4SLinus Torvalds } 4401da177e4SLinus Torvalds 441f2f0b00aSOleg Nesterov /** 442f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 443f2f0b00aSOleg Nesterov * 444f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 445f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 446f2f0b00aSOleg Nesterov */ 447e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 448f2f0b00aSOleg Nesterov { 449f2f0b00aSOleg Nesterov int ret = -EPERM; 450f2f0b00aSOleg Nesterov 4514b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 4524b105cbbSOleg Nesterov /* Are we already being traced? */ 453f2f0b00aSOleg Nesterov if (!current->ptrace) { 454f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 455f2f0b00aSOleg Nesterov /* 456f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 457f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 458f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 459f2f0b00aSOleg Nesterov */ 460f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 461f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 462f2f0b00aSOleg Nesterov __ptrace_link(current, current->real_parent); 463f2f0b00aSOleg Nesterov } 464f2f0b00aSOleg Nesterov } 4654b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 4664b105cbbSOleg Nesterov 467f2f0b00aSOleg Nesterov return ret; 468f2f0b00aSOleg Nesterov } 469f2f0b00aSOleg Nesterov 47039c626aeSOleg Nesterov /* 47139c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 47239c626aeSOleg Nesterov */ 47339c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 47439c626aeSOleg Nesterov { 47539c626aeSOleg Nesterov int ret; 47639c626aeSOleg Nesterov spin_lock(&sigh->siglock); 47739c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 47839c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 47939c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 48039c626aeSOleg Nesterov return ret; 48139c626aeSOleg Nesterov } 48239c626aeSOleg Nesterov 48339c626aeSOleg Nesterov /* 48439c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 48539c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 48639c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 48739c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 48839c626aeSOleg Nesterov * 48939c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 49039c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 49139c626aeSOleg Nesterov * If it should reap itself, return true. 49239c626aeSOleg Nesterov * 493a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 494a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 495a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 496a7f0765eSOleg Nesterov * do_wait(). 49739c626aeSOleg Nesterov */ 49839c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 49939c626aeSOleg Nesterov { 5009843a1e9SOleg Nesterov bool dead; 5019843a1e9SOleg Nesterov 50239c626aeSOleg Nesterov __ptrace_unlink(p); 50339c626aeSOleg Nesterov 5049843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 5059843a1e9SOleg Nesterov return false; 5069843a1e9SOleg Nesterov 5079843a1e9SOleg Nesterov dead = !thread_group_leader(p); 5089843a1e9SOleg Nesterov 5099843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 51039c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 5119843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 512a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 513a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 5149843a1e9SOleg Nesterov dead = true; 51539c626aeSOleg Nesterov } 516a7f0765eSOleg Nesterov } 51739c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 5189843a1e9SOleg Nesterov if (dead) 51939c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 5209843a1e9SOleg Nesterov return dead; 52139c626aeSOleg Nesterov } 52239c626aeSOleg Nesterov 523e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 5241da177e4SLinus Torvalds { 5257ed20e1aSJesper Juhl if (!valid_signal(data)) 5261da177e4SLinus Torvalds return -EIO; 5271da177e4SLinus Torvalds 5281da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 5291da177e4SLinus Torvalds ptrace_disable(child); 5301da177e4SLinus Torvalds 53195c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 53239c626aeSOleg Nesterov /* 53364a4096cSOleg Nesterov * We rely on ptrace_freeze_traced(). It can't be killed and 53464a4096cSOleg Nesterov * untraced by another thread, it can't be a zombie. 53539c626aeSOleg Nesterov */ 53664a4096cSOleg Nesterov WARN_ON(!child->ptrace || child->exit_state); 53764a4096cSOleg Nesterov /* 53864a4096cSOleg Nesterov * tasklist_lock avoids the race with wait_task_stopped(), see 53964a4096cSOleg Nesterov * the comment in ptrace_resume(). 54064a4096cSOleg Nesterov */ 54195c3eb76SOleg Nesterov child->exit_code = data; 54264a4096cSOleg Nesterov __ptrace_detach(current, child); 5431da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 5441da177e4SLinus Torvalds 545f701e5b7SVladimir Zapolskiy proc_ptrace_connector(child, PTRACE_DETACH); 5464576145cSOleg Nesterov 5471da177e4SLinus Torvalds return 0; 5481da177e4SLinus Torvalds } 5491da177e4SLinus Torvalds 55039c626aeSOleg Nesterov /* 551c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 5527c8bd232SOleg Nesterov * for writing. 55339c626aeSOleg Nesterov */ 5547c8bd232SOleg Nesterov void exit_ptrace(struct task_struct *tracer, struct list_head *dead) 55539c626aeSOleg Nesterov { 55639c626aeSOleg Nesterov struct task_struct *p, *n; 557c7e49c14SOleg Nesterov 55839c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 559992fb6e1SOleg Nesterov if (unlikely(p->ptrace & PT_EXITKILL)) 560992fb6e1SOleg Nesterov send_sig_info(SIGKILL, SEND_SIG_FORCED, p); 561992fb6e1SOleg Nesterov 56239c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 5637c8bd232SOleg Nesterov list_add(&p->ptrace_entry, dead); 56439c626aeSOleg Nesterov } 56539c626aeSOleg Nesterov } 56639c626aeSOleg Nesterov 5671da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 5681da177e4SLinus Torvalds { 5691da177e4SLinus Torvalds int copied = 0; 5701da177e4SLinus Torvalds 5711da177e4SLinus Torvalds while (len > 0) { 5721da177e4SLinus Torvalds char buf[128]; 5731da177e4SLinus Torvalds int this_len, retval; 5741da177e4SLinus Torvalds 5751da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 57684d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE); 57784d77d3fSEric W. Biederman 5781da177e4SLinus Torvalds if (!retval) { 5791da177e4SLinus Torvalds if (copied) 5801da177e4SLinus Torvalds break; 5811da177e4SLinus Torvalds return -EIO; 5821da177e4SLinus Torvalds } 5831da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 5841da177e4SLinus Torvalds return -EFAULT; 5851da177e4SLinus Torvalds copied += retval; 5861da177e4SLinus Torvalds src += retval; 5871da177e4SLinus Torvalds dst += retval; 5881da177e4SLinus Torvalds len -= retval; 5891da177e4SLinus Torvalds } 5901da177e4SLinus Torvalds return copied; 5911da177e4SLinus Torvalds } 5921da177e4SLinus Torvalds 5931da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 5941da177e4SLinus Torvalds { 5951da177e4SLinus Torvalds int copied = 0; 5961da177e4SLinus Torvalds 5971da177e4SLinus Torvalds while (len > 0) { 5981da177e4SLinus Torvalds char buf[128]; 5991da177e4SLinus Torvalds int this_len, retval; 6001da177e4SLinus Torvalds 6011da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 6021da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 6031da177e4SLinus Torvalds return -EFAULT; 60484d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, dst, buf, this_len, 605f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 6061da177e4SLinus Torvalds if (!retval) { 6071da177e4SLinus Torvalds if (copied) 6081da177e4SLinus Torvalds break; 6091da177e4SLinus Torvalds return -EIO; 6101da177e4SLinus Torvalds } 6111da177e4SLinus Torvalds copied += retval; 6121da177e4SLinus Torvalds src += retval; 6131da177e4SLinus Torvalds dst += retval; 6141da177e4SLinus Torvalds len -= retval; 6151da177e4SLinus Torvalds } 6161da177e4SLinus Torvalds return copied; 6171da177e4SLinus Torvalds } 6181da177e4SLinus Torvalds 6194abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 6201da177e4SLinus Torvalds { 62186b6c1f3SDenys Vlasenko unsigned flags; 62286b6c1f3SDenys Vlasenko 6238c5cf9e5SDenys Vlasenko if (data & ~(unsigned long)PTRACE_O_MASK) 6248c5cf9e5SDenys Vlasenko return -EINVAL; 6258c5cf9e5SDenys Vlasenko 62613c4a901STycho Andersen if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { 62797f2645fSMasahiro Yamada if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || 62897f2645fSMasahiro Yamada !IS_ENABLED(CONFIG_SECCOMP)) 62913c4a901STycho Andersen return -EINVAL; 63013c4a901STycho Andersen 63113c4a901STycho Andersen if (!capable(CAP_SYS_ADMIN)) 63213c4a901STycho Andersen return -EPERM; 63313c4a901STycho Andersen 63413c4a901STycho Andersen if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || 63513c4a901STycho Andersen current->ptrace & PT_SUSPEND_SECCOMP) 63613c4a901STycho Andersen return -EPERM; 63713c4a901STycho Andersen } 63813c4a901STycho Andersen 63986b6c1f3SDenys Vlasenko /* Avoid intermediate state when all opts are cleared */ 64086b6c1f3SDenys Vlasenko flags = child->ptrace; 64186b6c1f3SDenys Vlasenko flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); 64286b6c1f3SDenys Vlasenko flags |= (data << PT_OPT_FLAG_SHIFT); 64386b6c1f3SDenys Vlasenko child->ptrace = flags; 6441da177e4SLinus Torvalds 6458c5cf9e5SDenys Vlasenko return 0; 6461da177e4SLinus Torvalds } 6471da177e4SLinus Torvalds 648e16b2781SRoland McGrath static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) 6491da177e4SLinus Torvalds { 650e4961254SOleg Nesterov unsigned long flags; 6511da177e4SLinus Torvalds int error = -ESRCH; 6521da177e4SLinus Torvalds 653e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 6541da177e4SLinus Torvalds error = -EINVAL; 6551da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 656e16b2781SRoland McGrath *info = *child->last_siginfo; 6571da177e4SLinus Torvalds error = 0; 6581da177e4SLinus Torvalds } 659e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 6601da177e4SLinus Torvalds } 6611da177e4SLinus Torvalds return error; 6621da177e4SLinus Torvalds } 6631da177e4SLinus Torvalds 664e16b2781SRoland McGrath static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) 6651da177e4SLinus Torvalds { 666e4961254SOleg Nesterov unsigned long flags; 6671da177e4SLinus Torvalds int error = -ESRCH; 6681da177e4SLinus Torvalds 669e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 6701da177e4SLinus Torvalds error = -EINVAL; 6711da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 672e16b2781SRoland McGrath *child->last_siginfo = *info; 6731da177e4SLinus Torvalds error = 0; 6741da177e4SLinus Torvalds } 675e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 6761da177e4SLinus Torvalds } 6771da177e4SLinus Torvalds return error; 6781da177e4SLinus Torvalds } 6791da177e4SLinus Torvalds 68084c751bdSAndrey Vagin static int ptrace_peek_siginfo(struct task_struct *child, 68184c751bdSAndrey Vagin unsigned long addr, 68284c751bdSAndrey Vagin unsigned long data) 68384c751bdSAndrey Vagin { 68484c751bdSAndrey Vagin struct ptrace_peeksiginfo_args arg; 68584c751bdSAndrey Vagin struct sigpending *pending; 68684c751bdSAndrey Vagin struct sigqueue *q; 68784c751bdSAndrey Vagin int ret, i; 68884c751bdSAndrey Vagin 68984c751bdSAndrey Vagin ret = copy_from_user(&arg, (void __user *) addr, 69084c751bdSAndrey Vagin sizeof(struct ptrace_peeksiginfo_args)); 69184c751bdSAndrey Vagin if (ret) 69284c751bdSAndrey Vagin return -EFAULT; 69384c751bdSAndrey Vagin 69484c751bdSAndrey Vagin if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) 69584c751bdSAndrey Vagin return -EINVAL; /* unknown flags */ 69684c751bdSAndrey Vagin 69784c751bdSAndrey Vagin if (arg.nr < 0) 69884c751bdSAndrey Vagin return -EINVAL; 69984c751bdSAndrey Vagin 70084c751bdSAndrey Vagin if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) 70184c751bdSAndrey Vagin pending = &child->signal->shared_pending; 70284c751bdSAndrey Vagin else 70384c751bdSAndrey Vagin pending = &child->pending; 70484c751bdSAndrey Vagin 70584c751bdSAndrey Vagin for (i = 0; i < arg.nr; ) { 70684c751bdSAndrey Vagin siginfo_t info; 70784c751bdSAndrey Vagin s32 off = arg.off + i; 70884c751bdSAndrey Vagin 70984c751bdSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 71084c751bdSAndrey Vagin list_for_each_entry(q, &pending->list, list) { 71184c751bdSAndrey Vagin if (!off--) { 71284c751bdSAndrey Vagin copy_siginfo(&info, &q->info); 71384c751bdSAndrey Vagin break; 71484c751bdSAndrey Vagin } 71584c751bdSAndrey Vagin } 71684c751bdSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 71784c751bdSAndrey Vagin 71884c751bdSAndrey Vagin if (off >= 0) /* beyond the end of the list */ 71984c751bdSAndrey Vagin break; 72084c751bdSAndrey Vagin 72184c751bdSAndrey Vagin #ifdef CONFIG_COMPAT 7225c465217SAndy Lutomirski if (unlikely(in_compat_syscall())) { 72384c751bdSAndrey Vagin compat_siginfo_t __user *uinfo = compat_ptr(data); 72484c751bdSAndrey Vagin 725706b23bdSMathieu Desnoyers if (copy_siginfo_to_user32(uinfo, &info) || 726706b23bdSMathieu Desnoyers __put_user(info.si_code, &uinfo->si_code)) { 727706b23bdSMathieu Desnoyers ret = -EFAULT; 728706b23bdSMathieu Desnoyers break; 729706b23bdSMathieu Desnoyers } 730706b23bdSMathieu Desnoyers 73184c751bdSAndrey Vagin } else 73284c751bdSAndrey Vagin #endif 73384c751bdSAndrey Vagin { 73484c751bdSAndrey Vagin siginfo_t __user *uinfo = (siginfo_t __user *) data; 73584c751bdSAndrey Vagin 736706b23bdSMathieu Desnoyers if (copy_siginfo_to_user(uinfo, &info) || 737706b23bdSMathieu Desnoyers __put_user(info.si_code, &uinfo->si_code)) { 73884c751bdSAndrey Vagin ret = -EFAULT; 73984c751bdSAndrey Vagin break; 74084c751bdSAndrey Vagin } 741706b23bdSMathieu Desnoyers } 74284c751bdSAndrey Vagin 74384c751bdSAndrey Vagin data += sizeof(siginfo_t); 74484c751bdSAndrey Vagin i++; 74584c751bdSAndrey Vagin 74684c751bdSAndrey Vagin if (signal_pending(current)) 74784c751bdSAndrey Vagin break; 74884c751bdSAndrey Vagin 74984c751bdSAndrey Vagin cond_resched(); 75084c751bdSAndrey Vagin } 75184c751bdSAndrey Vagin 75284c751bdSAndrey Vagin if (i > 0) 75384c751bdSAndrey Vagin return i; 75484c751bdSAndrey Vagin 75584c751bdSAndrey Vagin return ret; 75684c751bdSAndrey Vagin } 75736df29d7SRoland McGrath 75836df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 75936df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 76036df29d7SRoland McGrath #else 76136df29d7SRoland McGrath #define is_singlestep(request) 0 76236df29d7SRoland McGrath #endif 76336df29d7SRoland McGrath 7645b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 7655b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 7665b88abbfSRoland McGrath #else 7675b88abbfSRoland McGrath #define is_singleblock(request) 0 7685b88abbfSRoland McGrath #endif 7695b88abbfSRoland McGrath 77036df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 77136df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 77236df29d7SRoland McGrath #else 77336df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 77436df29d7SRoland McGrath #endif 77536df29d7SRoland McGrath 7764abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 7774abf9869SNamhyung Kim unsigned long data) 77836df29d7SRoland McGrath { 779b72c1869SOleg Nesterov bool need_siglock; 780b72c1869SOleg Nesterov 78136df29d7SRoland McGrath if (!valid_signal(data)) 78236df29d7SRoland McGrath return -EIO; 78336df29d7SRoland McGrath 78436df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 78536df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 78636df29d7SRoland McGrath else 78736df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 78836df29d7SRoland McGrath 78936df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 79036df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 79136df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 79236df29d7SRoland McGrath else 79336df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 79436df29d7SRoland McGrath #endif 79536df29d7SRoland McGrath 7965b88abbfSRoland McGrath if (is_singleblock(request)) { 7975b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 7985b88abbfSRoland McGrath return -EIO; 7995b88abbfSRoland McGrath user_enable_block_step(child); 8005b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 80136df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 80236df29d7SRoland McGrath return -EIO; 80336df29d7SRoland McGrath user_enable_single_step(child); 8043a709703SRoland McGrath } else { 80536df29d7SRoland McGrath user_disable_single_step(child); 8063a709703SRoland McGrath } 80736df29d7SRoland McGrath 808b72c1869SOleg Nesterov /* 809b72c1869SOleg Nesterov * Change ->exit_code and ->state under siglock to avoid the race 810b72c1869SOleg Nesterov * with wait_task_stopped() in between; a non-zero ->exit_code will 811b72c1869SOleg Nesterov * wrongly look like another report from tracee. 812b72c1869SOleg Nesterov * 813b72c1869SOleg Nesterov * Note that we need siglock even if ->exit_code == data and/or this 814b72c1869SOleg Nesterov * status was not reported yet, the new status must not be cleared by 815b72c1869SOleg Nesterov * wait_task_stopped() after resume. 816b72c1869SOleg Nesterov * 817b72c1869SOleg Nesterov * If data == 0 we do not care if wait_task_stopped() reports the old 818b72c1869SOleg Nesterov * status and clears the code too; this can't race with the tracee, it 819b72c1869SOleg Nesterov * takes siglock after resume. 820b72c1869SOleg Nesterov */ 821b72c1869SOleg Nesterov need_siglock = data && !thread_group_empty(current); 822b72c1869SOleg Nesterov if (need_siglock) 823b72c1869SOleg Nesterov spin_lock_irq(&child->sighand->siglock); 82436df29d7SRoland McGrath child->exit_code = data; 8250666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 826b72c1869SOleg Nesterov if (need_siglock) 827b72c1869SOleg Nesterov spin_unlock_irq(&child->sighand->siglock); 82836df29d7SRoland McGrath 82936df29d7SRoland McGrath return 0; 83036df29d7SRoland McGrath } 83136df29d7SRoland McGrath 8322225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8332225a122SSuresh Siddha 8342225a122SSuresh Siddha static const struct user_regset * 8352225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 8362225a122SSuresh Siddha { 8372225a122SSuresh Siddha const struct user_regset *regset; 8382225a122SSuresh Siddha int n; 8392225a122SSuresh Siddha 8402225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 8412225a122SSuresh Siddha regset = view->regsets + n; 8422225a122SSuresh Siddha if (regset->core_note_type == type) 8432225a122SSuresh Siddha return regset; 8442225a122SSuresh Siddha } 8452225a122SSuresh Siddha 8462225a122SSuresh Siddha return NULL; 8472225a122SSuresh Siddha } 8482225a122SSuresh Siddha 8492225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 8502225a122SSuresh Siddha struct iovec *kiov) 8512225a122SSuresh Siddha { 8522225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 8532225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 8542225a122SSuresh Siddha int regset_no; 8552225a122SSuresh Siddha 8562225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 857c6a0dd7eSSuresh Siddha return -EINVAL; 8582225a122SSuresh Siddha 8592225a122SSuresh Siddha regset_no = regset - view->regsets; 8602225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 8612225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 8622225a122SSuresh Siddha 8632225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 8642225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 8652225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 8662225a122SSuresh Siddha else 8672225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 8682225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 8692225a122SSuresh Siddha } 8702225a122SSuresh Siddha 871e8440c14SJosh Stone /* 872e8440c14SJosh Stone * This is declared in linux/regset.h and defined in machine-dependent 873e8440c14SJosh Stone * code. We put the export here, near the primary machine-neutral use, 874e8440c14SJosh Stone * to ensure no machine forgets it. 875e8440c14SJosh Stone */ 876e8440c14SJosh Stone EXPORT_SYMBOL_GPL(task_user_regset_view); 8772225a122SSuresh Siddha #endif 8782225a122SSuresh Siddha 8791da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 8804abf9869SNamhyung Kim unsigned long addr, unsigned long data) 8811da177e4SLinus Torvalds { 882fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 8831da177e4SLinus Torvalds int ret = -EIO; 884544b2c91STejun Heo siginfo_t siginfo, *si; 8859fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 8869fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 887fca26f26STejun Heo unsigned long flags; 8881da177e4SLinus Torvalds 8891da177e4SLinus Torvalds switch (request) { 89016c3e389SRoland McGrath case PTRACE_PEEKTEXT: 89116c3e389SRoland McGrath case PTRACE_PEEKDATA: 89216c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 89316c3e389SRoland McGrath case PTRACE_POKETEXT: 89416c3e389SRoland McGrath case PTRACE_POKEDATA: 89516c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 89616c3e389SRoland McGrath 8971da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 8981da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 8991da177e4SLinus Torvalds #endif 9001da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 9011da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 9021da177e4SLinus Torvalds break; 9031da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 9049fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 9051da177e4SLinus Torvalds break; 906e16b2781SRoland McGrath 90784c751bdSAndrey Vagin case PTRACE_PEEKSIGINFO: 90884c751bdSAndrey Vagin ret = ptrace_peek_siginfo(child, addr, data); 90984c751bdSAndrey Vagin break; 91084c751bdSAndrey Vagin 9111da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 912e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 913e16b2781SRoland McGrath if (!ret) 9149fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 9151da177e4SLinus Torvalds break; 916e16b2781SRoland McGrath 9171da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 9189fed81dcSNamhyung Kim if (copy_from_user(&siginfo, datavp, sizeof siginfo)) 919e16b2781SRoland McGrath ret = -EFAULT; 920e16b2781SRoland McGrath else 921e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 9221da177e4SLinus Torvalds break; 923e16b2781SRoland McGrath 92429000caeSAndrey Vagin case PTRACE_GETSIGMASK: 92529000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 92629000caeSAndrey Vagin ret = -EINVAL; 92729000caeSAndrey Vagin break; 92829000caeSAndrey Vagin } 92929000caeSAndrey Vagin 93029000caeSAndrey Vagin if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t))) 93129000caeSAndrey Vagin ret = -EFAULT; 93229000caeSAndrey Vagin else 93329000caeSAndrey Vagin ret = 0; 93429000caeSAndrey Vagin 93529000caeSAndrey Vagin break; 93629000caeSAndrey Vagin 93729000caeSAndrey Vagin case PTRACE_SETSIGMASK: { 93829000caeSAndrey Vagin sigset_t new_set; 93929000caeSAndrey Vagin 94029000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 94129000caeSAndrey Vagin ret = -EINVAL; 94229000caeSAndrey Vagin break; 94329000caeSAndrey Vagin } 94429000caeSAndrey Vagin 94529000caeSAndrey Vagin if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { 94629000caeSAndrey Vagin ret = -EFAULT; 94729000caeSAndrey Vagin break; 94829000caeSAndrey Vagin } 94929000caeSAndrey Vagin 95029000caeSAndrey Vagin sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); 95129000caeSAndrey Vagin 95229000caeSAndrey Vagin /* 95329000caeSAndrey Vagin * Every thread does recalc_sigpending() after resume, so 95429000caeSAndrey Vagin * retarget_shared_pending() and recalc_sigpending() are not 95529000caeSAndrey Vagin * called here. 95629000caeSAndrey Vagin */ 95729000caeSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 95829000caeSAndrey Vagin child->blocked = new_set; 95929000caeSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 96029000caeSAndrey Vagin 96129000caeSAndrey Vagin ret = 0; 96229000caeSAndrey Vagin break; 96329000caeSAndrey Vagin } 96429000caeSAndrey Vagin 965fca26f26STejun Heo case PTRACE_INTERRUPT: 966fca26f26STejun Heo /* 967fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 968fca26f26STejun Heo * control. At least one trap is guaranteed to happen 969fca26f26STejun Heo * after this request. If @child is already trapped, the 970fca26f26STejun Heo * current trap is not disturbed and another trap will 971fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 972fca26f26STejun Heo * 973fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 974fca26f26STejun Heo * the pending condition is cleared regardless. 975fca26f26STejun Heo */ 976fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 977fca26f26STejun Heo break; 978fca26f26STejun Heo 979544b2c91STejun Heo /* 980544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 981544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 982544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 983544b2c91STejun Heo * tracee into STOP. 984544b2c91STejun Heo */ 985fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 986910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 987544b2c91STejun Heo 988544b2c91STejun Heo unlock_task_sighand(child, &flags); 989544b2c91STejun Heo ret = 0; 990544b2c91STejun Heo break; 991544b2c91STejun Heo 992544b2c91STejun Heo case PTRACE_LISTEN: 993544b2c91STejun Heo /* 994544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 995544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 996544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 997544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 998544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 999544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 1000544b2c91STejun Heo */ 1001544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 1002544b2c91STejun Heo break; 1003544b2c91STejun Heo 1004544b2c91STejun Heo si = child->last_siginfo; 1005f9d81f61SOleg Nesterov if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { 1006544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 1007544b2c91STejun Heo /* 1008f9d81f61SOleg Nesterov * If NOTIFY is set, it means event happened between 1009f9d81f61SOleg Nesterov * start of this trap and now. Trigger re-trap. 1010544b2c91STejun Heo */ 1011544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 1012910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 1013fca26f26STejun Heo ret = 0; 1014f9d81f61SOleg Nesterov } 1015f9d81f61SOleg Nesterov unlock_task_sighand(child, &flags); 1016fca26f26STejun Heo break; 1017fca26f26STejun Heo 10181bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 10191bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 10201bcf5482SAlexey Dobriyan break; 102136df29d7SRoland McGrath 10229c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 10239c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 1024e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 10259c1a1259SMike Frysinger unsigned long tmp = 0; 10269c1a1259SMike Frysinger 1027e0129ef9SOleg Nesterov ret = -ESRCH; 1028e0129ef9SOleg Nesterov if (!mm) 1029e0129ef9SOleg Nesterov break; 1030e0129ef9SOleg Nesterov 10319c1a1259SMike Frysinger switch (addr) { 10329c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 1033e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 10349c1a1259SMike Frysinger break; 10359c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 1036e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 10379c1a1259SMike Frysinger break; 10389c1a1259SMike Frysinger default: 10399c1a1259SMike Frysinger break; 10409c1a1259SMike Frysinger } 1041e0129ef9SOleg Nesterov mmput(mm); 10429c1a1259SMike Frysinger 10439fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 10449c1a1259SMike Frysinger break; 10459c1a1259SMike Frysinger } 10469c1a1259SMike Frysinger #endif 10479c1a1259SMike Frysinger 104836df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 104936df29d7SRoland McGrath case PTRACE_SINGLESTEP: 105036df29d7SRoland McGrath #endif 10515b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 10525b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 10535b88abbfSRoland McGrath #endif 105436df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 105536df29d7SRoland McGrath case PTRACE_SYSEMU: 105636df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 105736df29d7SRoland McGrath #endif 105836df29d7SRoland McGrath case PTRACE_SYSCALL: 105936df29d7SRoland McGrath case PTRACE_CONT: 106036df29d7SRoland McGrath return ptrace_resume(child, request, data); 106136df29d7SRoland McGrath 106236df29d7SRoland McGrath case PTRACE_KILL: 106336df29d7SRoland McGrath if (child->exit_state) /* already dead */ 106436df29d7SRoland McGrath return 0; 106536df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 106636df29d7SRoland McGrath 10672225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 10682225a122SSuresh Siddha case PTRACE_GETREGSET: 106929000caeSAndrey Vagin case PTRACE_SETREGSET: { 10702225a122SSuresh Siddha struct iovec kiov; 10719fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 10722225a122SSuresh Siddha 10732225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 10742225a122SSuresh Siddha return -EFAULT; 10752225a122SSuresh Siddha 10762225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 10772225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 10782225a122SSuresh Siddha return -EFAULT; 10792225a122SSuresh Siddha 10802225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 10812225a122SSuresh Siddha if (!ret) 10822225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 10832225a122SSuresh Siddha break; 10842225a122SSuresh Siddha } 10852225a122SSuresh Siddha #endif 1086f8e529edSTycho Andersen 1087f8e529edSTycho Andersen case PTRACE_SECCOMP_GET_FILTER: 1088f8e529edSTycho Andersen ret = seccomp_get_filter(child, addr, datavp); 1089f8e529edSTycho Andersen break; 1090f8e529edSTycho Andersen 10911da177e4SLinus Torvalds default: 10921da177e4SLinus Torvalds break; 10931da177e4SLinus Torvalds } 10941da177e4SLinus Torvalds 10951da177e4SLinus Torvalds return ret; 10961da177e4SLinus Torvalds } 1097481bed45SChristoph Hellwig 10988053bdd5SOleg Nesterov static struct task_struct *ptrace_get_task_struct(pid_t pid) 10996b9c7ed8SChristoph Hellwig { 11006b9c7ed8SChristoph Hellwig struct task_struct *child; 11016b9c7ed8SChristoph Hellwig 11028053bdd5SOleg Nesterov rcu_read_lock(); 1103228ebcbeSPavel Emelyanov child = find_task_by_vpid(pid); 1104481bed45SChristoph Hellwig if (child) 1105481bed45SChristoph Hellwig get_task_struct(child); 11068053bdd5SOleg Nesterov rcu_read_unlock(); 1107f400e198SSukadev Bhattiprolu 1108481bed45SChristoph Hellwig if (!child) 11096b9c7ed8SChristoph Hellwig return ERR_PTR(-ESRCH); 11106b9c7ed8SChristoph Hellwig return child; 1111481bed45SChristoph Hellwig } 1112481bed45SChristoph Hellwig 11130ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 11140ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 11150ac15559SChristoph Hellwig #endif 11160ac15559SChristoph Hellwig 11174abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 11184abf9869SNamhyung Kim unsigned long, data) 1119481bed45SChristoph Hellwig { 1120481bed45SChristoph Hellwig struct task_struct *child; 1121481bed45SChristoph Hellwig long ret; 1122481bed45SChristoph Hellwig 11236b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 11246b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 11256ea6dd93SHaavard Skinnemoen if (!ret) 11266ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 1127481bed45SChristoph Hellwig goto out; 11286b9c7ed8SChristoph Hellwig } 11296b9c7ed8SChristoph Hellwig 11306b9c7ed8SChristoph Hellwig child = ptrace_get_task_struct(pid); 11316b9c7ed8SChristoph Hellwig if (IS_ERR(child)) { 11326b9c7ed8SChristoph Hellwig ret = PTR_ERR(child); 11336b9c7ed8SChristoph Hellwig goto out; 11346b9c7ed8SChristoph Hellwig } 1135481bed45SChristoph Hellwig 11363544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1137aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 11380ac15559SChristoph Hellwig /* 11390ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 11400ac15559SChristoph Hellwig * a ptrace attach. 11410ac15559SChristoph Hellwig */ 11420ac15559SChristoph Hellwig if (!ret) 11430ac15559SChristoph Hellwig arch_ptrace_attach(child); 1144005f18dfSChristoph Hellwig goto out_put_task_struct; 1145481bed45SChristoph Hellwig } 1146481bed45SChristoph Hellwig 1147fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1148fca26f26STejun Heo request == PTRACE_INTERRUPT); 1149481bed45SChristoph Hellwig if (ret < 0) 1150481bed45SChristoph Hellwig goto out_put_task_struct; 1151481bed45SChristoph Hellwig 1152481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 11539899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 11549899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 1155481bed45SChristoph Hellwig 1156481bed45SChristoph Hellwig out_put_task_struct: 1157481bed45SChristoph Hellwig put_task_struct(child); 1158481bed45SChristoph Hellwig out: 1159481bed45SChristoph Hellwig return ret; 1160481bed45SChristoph Hellwig } 116176647323SAlexey Dobriyan 11624abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 11634abf9869SNamhyung Kim unsigned long data) 116476647323SAlexey Dobriyan { 116576647323SAlexey Dobriyan unsigned long tmp; 116676647323SAlexey Dobriyan int copied; 116776647323SAlexey Dobriyan 116884d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); 116976647323SAlexey Dobriyan if (copied != sizeof(tmp)) 117076647323SAlexey Dobriyan return -EIO; 117176647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 117276647323SAlexey Dobriyan } 1173f284ce72SAlexey Dobriyan 11744abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 11754abf9869SNamhyung Kim unsigned long data) 1176f284ce72SAlexey Dobriyan { 1177f284ce72SAlexey Dobriyan int copied; 1178f284ce72SAlexey Dobriyan 117984d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &data, sizeof(data), 1180f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1181f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 1182f284ce72SAlexey Dobriyan } 1183032d82d9SRoland McGrath 118496b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 1185032d82d9SRoland McGrath 1186032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 1187032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 1188032d82d9SRoland McGrath { 1189032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 1190032d82d9SRoland McGrath compat_ulong_t word; 1191e16b2781SRoland McGrath siginfo_t siginfo; 1192032d82d9SRoland McGrath int ret; 1193032d82d9SRoland McGrath 1194032d82d9SRoland McGrath switch (request) { 1195032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 1196032d82d9SRoland McGrath case PTRACE_PEEKDATA: 119784d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &word, sizeof(word), 1198f307ab6dSLorenzo Stoakes FOLL_FORCE); 1199032d82d9SRoland McGrath if (ret != sizeof(word)) 1200032d82d9SRoland McGrath ret = -EIO; 1201032d82d9SRoland McGrath else 1202032d82d9SRoland McGrath ret = put_user(word, datap); 1203032d82d9SRoland McGrath break; 1204032d82d9SRoland McGrath 1205032d82d9SRoland McGrath case PTRACE_POKETEXT: 1206032d82d9SRoland McGrath case PTRACE_POKEDATA: 120784d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &data, sizeof(data), 1208f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1209032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 1210032d82d9SRoland McGrath break; 1211032d82d9SRoland McGrath 1212032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 1213032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 1214032d82d9SRoland McGrath break; 1215032d82d9SRoland McGrath 1216e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 1217e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 1218e16b2781SRoland McGrath if (!ret) 1219e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 1220e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 1221e16b2781SRoland McGrath &siginfo); 1222e16b2781SRoland McGrath break; 1223e16b2781SRoland McGrath 1224e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 1225e16b2781SRoland McGrath memset(&siginfo, 0, sizeof siginfo); 1226e16b2781SRoland McGrath if (copy_siginfo_from_user32( 1227e16b2781SRoland McGrath &siginfo, (struct compat_siginfo __user *) datap)) 1228e16b2781SRoland McGrath ret = -EFAULT; 1229e16b2781SRoland McGrath else 1230e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 1231e16b2781SRoland McGrath break; 12322225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 12332225a122SSuresh Siddha case PTRACE_GETREGSET: 12342225a122SSuresh Siddha case PTRACE_SETREGSET: 12352225a122SSuresh Siddha { 12362225a122SSuresh Siddha struct iovec kiov; 12372225a122SSuresh Siddha struct compat_iovec __user *uiov = 12382225a122SSuresh Siddha (struct compat_iovec __user *) datap; 12392225a122SSuresh Siddha compat_uptr_t ptr; 12402225a122SSuresh Siddha compat_size_t len; 12412225a122SSuresh Siddha 12422225a122SSuresh Siddha if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) 12432225a122SSuresh Siddha return -EFAULT; 12442225a122SSuresh Siddha 12452225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 12462225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 12472225a122SSuresh Siddha return -EFAULT; 12482225a122SSuresh Siddha 12492225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 12502225a122SSuresh Siddha kiov.iov_len = len; 12512225a122SSuresh Siddha 12522225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 12532225a122SSuresh Siddha if (!ret) 12542225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 12552225a122SSuresh Siddha break; 12562225a122SSuresh Siddha } 12572225a122SSuresh Siddha #endif 1258e16b2781SRoland McGrath 1259032d82d9SRoland McGrath default: 1260032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 1261032d82d9SRoland McGrath } 1262032d82d9SRoland McGrath 1263032d82d9SRoland McGrath return ret; 1264032d82d9SRoland McGrath } 1265c269f196SRoland McGrath 126662a6fa97SHeiko Carstens COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, 126762a6fa97SHeiko Carstens compat_long_t, addr, compat_long_t, data) 1268c269f196SRoland McGrath { 1269c269f196SRoland McGrath struct task_struct *child; 1270c269f196SRoland McGrath long ret; 1271c269f196SRoland McGrath 1272c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1273c269f196SRoland McGrath ret = ptrace_traceme(); 1274c269f196SRoland McGrath goto out; 1275c269f196SRoland McGrath } 1276c269f196SRoland McGrath 1277c269f196SRoland McGrath child = ptrace_get_task_struct(pid); 1278c269f196SRoland McGrath if (IS_ERR(child)) { 1279c269f196SRoland McGrath ret = PTR_ERR(child); 1280c269f196SRoland McGrath goto out; 1281c269f196SRoland McGrath } 1282c269f196SRoland McGrath 12833544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1284aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 1285c269f196SRoland McGrath /* 1286c269f196SRoland McGrath * Some architectures need to do book-keeping after 1287c269f196SRoland McGrath * a ptrace attach. 1288c269f196SRoland McGrath */ 1289c269f196SRoland McGrath if (!ret) 1290c269f196SRoland McGrath arch_ptrace_attach(child); 1291c269f196SRoland McGrath goto out_put_task_struct; 1292c269f196SRoland McGrath } 1293c269f196SRoland McGrath 1294fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1295fca26f26STejun Heo request == PTRACE_INTERRUPT); 12969899d11fSOleg Nesterov if (!ret) { 1297c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 12989899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 12999899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 13009899d11fSOleg Nesterov } 1301c269f196SRoland McGrath 1302c269f196SRoland McGrath out_put_task_struct: 1303c269f196SRoland McGrath put_task_struct(child); 1304c269f196SRoland McGrath out: 1305c269f196SRoland McGrath return ret; 1306c269f196SRoland McGrath } 130796b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1308