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> 32fcfc2aa0SAndrei Vagin #include <linux/sched/signal.h> 331da177e4SLinus Torvalds 3484d77d3fSEric W. Biederman /* 3584d77d3fSEric W. Biederman * Access another process' address space via ptrace. 3684d77d3fSEric W. Biederman * Source/target buffer must be kernel space, 3784d77d3fSEric W. Biederman * Do not walk the page table directly, use get_user_pages 3884d77d3fSEric W. Biederman */ 3984d77d3fSEric W. Biederman int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, 4084d77d3fSEric W. Biederman void *buf, int len, unsigned int gup_flags) 4184d77d3fSEric W. Biederman { 4284d77d3fSEric W. Biederman struct mm_struct *mm; 4384d77d3fSEric W. Biederman int ret; 4484d77d3fSEric W. Biederman 4584d77d3fSEric W. Biederman mm = get_task_mm(tsk); 4684d77d3fSEric W. Biederman if (!mm) 4784d77d3fSEric W. Biederman return 0; 4884d77d3fSEric W. Biederman 4984d77d3fSEric W. Biederman if (!tsk->ptrace || 5084d77d3fSEric W. Biederman (current != tsk->parent) || 5184d77d3fSEric W. Biederman ((get_dumpable(mm) != SUID_DUMP_USER) && 5284d77d3fSEric W. Biederman !ptracer_capable(tsk, mm->user_ns))) { 5384d77d3fSEric W. Biederman mmput(mm); 5484d77d3fSEric W. Biederman return 0; 5584d77d3fSEric W. Biederman } 5684d77d3fSEric W. Biederman 5784d77d3fSEric W. Biederman ret = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags); 5884d77d3fSEric W. Biederman mmput(mm); 5984d77d3fSEric W. Biederman 6084d77d3fSEric W. Biederman return ret; 6184d77d3fSEric W. Biederman } 6284d77d3fSEric W. Biederman 63bf53de90SMarkus Metzger 64c70d9d80SEric W. Biederman void __ptrace_link(struct task_struct *child, struct task_struct *new_parent, 65c70d9d80SEric W. Biederman const struct cred *ptracer_cred) 66c70d9d80SEric W. Biederman { 67c70d9d80SEric W. Biederman BUG_ON(!list_empty(&child->ptrace_entry)); 68c70d9d80SEric W. Biederman list_add(&child->ptrace_entry, &new_parent->ptraced); 69c70d9d80SEric W. Biederman child->parent = new_parent; 70c70d9d80SEric W. Biederman child->ptracer_cred = get_cred(ptracer_cred); 71c70d9d80SEric W. Biederman } 72c70d9d80SEric W. Biederman 73bf53de90SMarkus Metzger /* 741da177e4SLinus Torvalds * ptrace a task: make the debugger its new parent and 751da177e4SLinus Torvalds * move it to the ptrace list. 761da177e4SLinus Torvalds * 771da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 781da177e4SLinus Torvalds */ 79c70d9d80SEric W. Biederman static void ptrace_link(struct task_struct *child, struct task_struct *new_parent) 801da177e4SLinus Torvalds { 8164b875f7SEric W. Biederman rcu_read_lock(); 82c70d9d80SEric W. Biederman __ptrace_link(child, new_parent, __task_cred(new_parent)); 8364b875f7SEric W. Biederman rcu_read_unlock(); 841da177e4SLinus Torvalds } 851da177e4SLinus Torvalds 86e3bd058fSTejun Heo /** 87e3bd058fSTejun Heo * __ptrace_unlink - unlink ptracee and restore its execution state 88e3bd058fSTejun Heo * @child: ptracee to be unlinked 891da177e4SLinus Torvalds * 900e9f0a4aSTejun Heo * Remove @child from the ptrace list, move it back to the original parent, 910e9f0a4aSTejun Heo * and restore the execution state so that it conforms to the group stop 920e9f0a4aSTejun Heo * state. 930e9f0a4aSTejun Heo * 940e9f0a4aSTejun Heo * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer 950e9f0a4aSTejun Heo * exiting. For PTRACE_DETACH, unless the ptracee has been killed between 960e9f0a4aSTejun Heo * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. 970e9f0a4aSTejun Heo * If the ptracer is exiting, the ptracee can be in any state. 980e9f0a4aSTejun Heo * 990e9f0a4aSTejun Heo * After detach, the ptracee should be in a state which conforms to the 1000e9f0a4aSTejun Heo * group stop. If the group is stopped or in the process of stopping, the 1010e9f0a4aSTejun Heo * ptracee should be put into TASK_STOPPED; otherwise, it should be woken 1020e9f0a4aSTejun Heo * up from TASK_TRACED. 1030e9f0a4aSTejun Heo * 1040e9f0a4aSTejun Heo * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, 1050e9f0a4aSTejun Heo * it goes through TRACED -> RUNNING -> STOPPED transition which is similar 1060e9f0a4aSTejun Heo * to but in the opposite direction of what happens while attaching to a 1070e9f0a4aSTejun Heo * stopped task. However, in this direction, the intermediate RUNNING 1080e9f0a4aSTejun Heo * state is not hidden even from the current ptracer and if it immediately 1090e9f0a4aSTejun Heo * re-attaches and performs a WNOHANG wait(2), it may fail. 110e3bd058fSTejun Heo * 111e3bd058fSTejun Heo * CONTEXT: 112e3bd058fSTejun Heo * write_lock_irq(tasklist_lock) 1131da177e4SLinus Torvalds */ 11436c8b586SIngo Molnar void __ptrace_unlink(struct task_struct *child) 1151da177e4SLinus Torvalds { 11664b875f7SEric W. Biederman const struct cred *old_cred; 1175ecfbae0SOleg Nesterov BUG_ON(!child->ptrace); 1185ecfbae0SOleg Nesterov 1190a5bf409SAles Novak clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 1200a5bf409SAles Novak 1211da177e4SLinus Torvalds child->parent = child->real_parent; 122f470021aSRoland McGrath list_del_init(&child->ptrace_entry); 12364b875f7SEric W. Biederman old_cred = child->ptracer_cred; 12464b875f7SEric W. Biederman child->ptracer_cred = NULL; 12564b875f7SEric W. Biederman put_cred(old_cred); 1261da177e4SLinus Torvalds 1271da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 1281333ab03SOleg Nesterov child->ptrace = 0; 1291da177e4SLinus Torvalds /* 13073ddff2bSTejun Heo * Clear all pending traps and TRAPPING. TRAPPING should be 13173ddff2bSTejun Heo * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. 13273ddff2bSTejun Heo */ 13373ddff2bSTejun Heo task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); 13473ddff2bSTejun Heo task_clear_jobctl_trapping(child); 13573ddff2bSTejun Heo 13673ddff2bSTejun Heo /* 137a8f072c1STejun Heo * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and 1380e9f0a4aSTejun Heo * @child isn't dead. 1391da177e4SLinus Torvalds */ 1400e9f0a4aSTejun Heo if (!(child->flags & PF_EXITING) && 1410e9f0a4aSTejun Heo (child->signal->flags & SIGNAL_STOP_STOPPED || 1428a88951bSOleg Nesterov child->signal->group_stop_count)) { 143a8f072c1STejun Heo child->jobctl |= JOBCTL_STOP_PENDING; 1440e9f0a4aSTejun Heo 1450e9f0a4aSTejun Heo /* 1468a88951bSOleg Nesterov * This is only possible if this thread was cloned by the 1478a88951bSOleg Nesterov * traced task running in the stopped group, set the signal 1488a88951bSOleg Nesterov * for the future reports. 1498a88951bSOleg Nesterov * FIXME: we should change ptrace_init_task() to handle this 1508a88951bSOleg Nesterov * case. 1518a88951bSOleg Nesterov */ 1528a88951bSOleg Nesterov if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) 1538a88951bSOleg Nesterov child->jobctl |= SIGSTOP; 1548a88951bSOleg Nesterov } 1558a88951bSOleg Nesterov 1568a88951bSOleg Nesterov /* 1570e9f0a4aSTejun Heo * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick 1580e9f0a4aSTejun Heo * @child in the butt. Note that @resume should be used iff @child 1590e9f0a4aSTejun Heo * is in TASK_TRACED; otherwise, we might unduly disrupt 1600e9f0a4aSTejun Heo * TASK_KILLABLE sleeps. 1610e9f0a4aSTejun Heo */ 162a8f072c1STejun Heo if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) 163910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 1640e9f0a4aSTejun Heo 1651da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 1661da177e4SLinus Torvalds } 1671da177e4SLinus Torvalds 1689899d11fSOleg Nesterov /* Ensure that nothing can wake it up, even SIGKILL */ 1699899d11fSOleg Nesterov static bool ptrace_freeze_traced(struct task_struct *task) 1709899d11fSOleg Nesterov { 1719899d11fSOleg Nesterov bool ret = false; 1729899d11fSOleg Nesterov 1739899d11fSOleg Nesterov /* Lockless, nobody but us can set this flag */ 1749899d11fSOleg Nesterov if (task->jobctl & JOBCTL_LISTENING) 1759899d11fSOleg Nesterov return ret; 1769899d11fSOleg Nesterov 1779899d11fSOleg Nesterov spin_lock_irq(&task->sighand->siglock); 1789899d11fSOleg Nesterov if (task_is_traced(task) && !__fatal_signal_pending(task)) { 1799899d11fSOleg Nesterov task->state = __TASK_TRACED; 1809899d11fSOleg Nesterov ret = true; 1819899d11fSOleg Nesterov } 1829899d11fSOleg Nesterov spin_unlock_irq(&task->sighand->siglock); 1839899d11fSOleg Nesterov 1849899d11fSOleg Nesterov return ret; 1859899d11fSOleg Nesterov } 1869899d11fSOleg Nesterov 1879899d11fSOleg Nesterov static void ptrace_unfreeze_traced(struct task_struct *task) 1889899d11fSOleg Nesterov { 1899899d11fSOleg Nesterov if (task->state != __TASK_TRACED) 1909899d11fSOleg Nesterov return; 1919899d11fSOleg Nesterov 1929899d11fSOleg Nesterov WARN_ON(!task->ptrace || task->parent != current); 1939899d11fSOleg Nesterov 1945402e97aSbsegall@google.com /* 1955402e97aSbsegall@google.com * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely. 1965402e97aSbsegall@google.com * Recheck state under the lock to close this race. 1975402e97aSbsegall@google.com */ 1989899d11fSOleg Nesterov spin_lock_irq(&task->sighand->siglock); 1995402e97aSbsegall@google.com if (task->state == __TASK_TRACED) { 2009899d11fSOleg Nesterov if (__fatal_signal_pending(task)) 2019899d11fSOleg Nesterov wake_up_state(task, __TASK_TRACED); 2029899d11fSOleg Nesterov else 2039899d11fSOleg Nesterov task->state = TASK_TRACED; 2045402e97aSbsegall@google.com } 2059899d11fSOleg Nesterov spin_unlock_irq(&task->sighand->siglock); 2069899d11fSOleg Nesterov } 2079899d11fSOleg Nesterov 208755e276bSTejun Heo /** 209755e276bSTejun Heo * ptrace_check_attach - check whether ptracee is ready for ptrace operation 210755e276bSTejun Heo * @child: ptracee to check for 211755e276bSTejun Heo * @ignore_state: don't check whether @child is currently %TASK_TRACED 212755e276bSTejun Heo * 213755e276bSTejun Heo * Check whether @child is being ptraced by %current and ready for further 214755e276bSTejun Heo * ptrace operations. If @ignore_state is %false, @child also should be in 215755e276bSTejun Heo * %TASK_TRACED state and on return the child is guaranteed to be traced 216755e276bSTejun Heo * and not executing. If @ignore_state is %true, @child can be in any 217755e276bSTejun Heo * state. 218755e276bSTejun Heo * 219755e276bSTejun Heo * CONTEXT: 220755e276bSTejun Heo * Grabs and releases tasklist_lock and @child->sighand->siglock. 221755e276bSTejun Heo * 222755e276bSTejun Heo * RETURNS: 223755e276bSTejun Heo * 0 on success, -ESRCH if %child is not ready. 2241da177e4SLinus Torvalds */ 225edea0d03SOleg Nesterov static int ptrace_check_attach(struct task_struct *child, bool ignore_state) 2261da177e4SLinus Torvalds { 2271da177e4SLinus Torvalds int ret = -ESRCH; 2281da177e4SLinus Torvalds 2291da177e4SLinus Torvalds /* 2301da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 2311da177e4SLinus Torvalds * possible race where someone else was tracing our child and 2321da177e4SLinus Torvalds * detached between these two checks. After this locked check, 2331da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 2341da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 2351da177e4SLinus Torvalds */ 2361da177e4SLinus Torvalds read_lock(&tasklist_lock); 2379899d11fSOleg Nesterov if (child->ptrace && child->parent == current) { 2389899d11fSOleg Nesterov WARN_ON(child->state == __TASK_TRACED); 239c0c0b649SOleg Nesterov /* 240c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 241c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 242c0c0b649SOleg Nesterov */ 2439899d11fSOleg Nesterov if (ignore_state || ptrace_freeze_traced(child)) 244321fb561SOleg Nesterov ret = 0; 2451da177e4SLinus Torvalds } 2461da177e4SLinus Torvalds read_unlock(&tasklist_lock); 2471da177e4SLinus Torvalds 2489899d11fSOleg Nesterov if (!ret && !ignore_state) { 2499899d11fSOleg Nesterov if (!wait_task_inactive(child, __TASK_TRACED)) { 2509899d11fSOleg Nesterov /* 2519899d11fSOleg Nesterov * This can only happen if may_ptrace_stop() fails and 2529899d11fSOleg Nesterov * ptrace_stop() changes ->state back to TASK_RUNNING, 2539899d11fSOleg Nesterov * so we should not worry about leaking __TASK_TRACED. 2549899d11fSOleg Nesterov */ 2559899d11fSOleg Nesterov WARN_ON(child->state == __TASK_TRACED); 2569899d11fSOleg Nesterov ret = -ESRCH; 2579899d11fSOleg Nesterov } 2589899d11fSOleg Nesterov } 2591da177e4SLinus Torvalds 2601da177e4SLinus Torvalds return ret; 2611da177e4SLinus Torvalds } 2621da177e4SLinus Torvalds 26369f594a3SEric Paris static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) 26469f594a3SEric Paris { 26569f594a3SEric Paris if (mode & PTRACE_MODE_NOAUDIT) 26669f594a3SEric Paris return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); 26769f594a3SEric Paris else 26869f594a3SEric Paris return has_ns_capability(current, ns, CAP_SYS_PTRACE); 26969f594a3SEric Paris } 27069f594a3SEric Paris 2719f99798fSTetsuo Handa /* Returns 0 on success, -errno on denial. */ 2729f99798fSTetsuo Handa static int __ptrace_may_access(struct task_struct *task, unsigned int mode) 273ab8d11beSMiklos Szeredi { 274c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 275bfedb589SEric W. Biederman struct mm_struct *mm; 276caaee623SJann Horn kuid_t caller_uid; 277caaee623SJann Horn kgid_t caller_gid; 278caaee623SJann Horn 279caaee623SJann Horn if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { 280caaee623SJann Horn WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); 281caaee623SJann Horn return -EPERM; 282caaee623SJann Horn } 283b6dff3ecSDavid Howells 284df26c40eSEric W. Biederman /* May we inspect the given task? 285df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 286df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 287df26c40eSEric W. Biederman * 288df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 289df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 290df26c40eSEric W. Biederman * or halting the specified task is impossible. 291df26c40eSEric W. Biederman */ 292caaee623SJann Horn 293df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 29473af963fSMark Grondona if (same_thread_group(task, current)) 295df26c40eSEric W. Biederman return 0; 296c69e8d9cSDavid Howells rcu_read_lock(); 297caaee623SJann Horn if (mode & PTRACE_MODE_FSCREDS) { 298caaee623SJann Horn caller_uid = cred->fsuid; 299caaee623SJann Horn caller_gid = cred->fsgid; 300caaee623SJann Horn } else { 301caaee623SJann Horn /* 302caaee623SJann Horn * Using the euid would make more sense here, but something 303caaee623SJann Horn * in userland might rely on the old behavior, and this 304caaee623SJann Horn * shouldn't be a security problem since 305caaee623SJann Horn * PTRACE_MODE_REALCREDS implies that the caller explicitly 306caaee623SJann Horn * used a syscall that requests access to another process 307caaee623SJann Horn * (and not a filesystem syscall to procfs). 308caaee623SJann Horn */ 309caaee623SJann Horn caller_uid = cred->uid; 310caaee623SJann Horn caller_gid = cred->gid; 311caaee623SJann Horn } 312c69e8d9cSDavid Howells tcred = __task_cred(task); 313caaee623SJann Horn if (uid_eq(caller_uid, tcred->euid) && 314caaee623SJann Horn uid_eq(caller_uid, tcred->suid) && 315caaee623SJann Horn uid_eq(caller_uid, tcred->uid) && 316caaee623SJann Horn gid_eq(caller_gid, tcred->egid) && 317caaee623SJann Horn gid_eq(caller_gid, tcred->sgid) && 318caaee623SJann Horn gid_eq(caller_gid, tcred->gid)) 3198409cca7SSerge E. Hallyn goto ok; 320c4a4d603SEric W. Biederman if (ptrace_has_cap(tcred->user_ns, mode)) 3218409cca7SSerge E. Hallyn goto ok; 322c69e8d9cSDavid Howells rcu_read_unlock(); 323ab8d11beSMiklos Szeredi return -EPERM; 3248409cca7SSerge E. Hallyn ok: 325c69e8d9cSDavid Howells rcu_read_unlock(); 326bfedb589SEric W. Biederman mm = task->mm; 327bfedb589SEric W. Biederman if (mm && 328bfedb589SEric W. Biederman ((get_dumpable(mm) != SUID_DUMP_USER) && 329bfedb589SEric W. Biederman !ptrace_has_cap(mm->user_ns, mode))) 330ab8d11beSMiklos Szeredi return -EPERM; 331ab8d11beSMiklos Szeredi 3329e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 333ab8d11beSMiklos Szeredi } 334ab8d11beSMiklos Szeredi 335006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 336ab8d11beSMiklos Szeredi { 337ab8d11beSMiklos Szeredi int err; 338ab8d11beSMiklos Szeredi task_lock(task); 339006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 340ab8d11beSMiklos Szeredi task_unlock(task); 3413a709703SRoland McGrath return !err; 342ab8d11beSMiklos Szeredi } 343ab8d11beSMiklos Szeredi 3443544d72aSTejun Heo static int ptrace_attach(struct task_struct *task, long request, 345aa9147c9SDenys Vlasenko unsigned long addr, 3463544d72aSTejun Heo unsigned long flags) 3471da177e4SLinus Torvalds { 3483544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 3491da177e4SLinus Torvalds int retval; 350f5b40e36SLinus Torvalds 3513544d72aSTejun Heo retval = -EIO; 352aa9147c9SDenys Vlasenko if (seize) { 353aa9147c9SDenys Vlasenko if (addr != 0) 3543544d72aSTejun Heo goto out; 355aa9147c9SDenys Vlasenko if (flags & ~(unsigned long)PTRACE_O_MASK) 356aa9147c9SDenys Vlasenko goto out; 357aa9147c9SDenys Vlasenko flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); 358aa9147c9SDenys Vlasenko } else { 359aa9147c9SDenys Vlasenko flags = PT_PTRACED; 360aa9147c9SDenys Vlasenko } 3613544d72aSTejun Heo 362a5cb013dSAl Viro audit_ptrace(task); 363a5cb013dSAl Viro 3641da177e4SLinus Torvalds retval = -EPERM; 365b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 366b79b7ba9SOleg Nesterov goto out; 367bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 368f5b40e36SLinus Torvalds goto out; 369f5b40e36SLinus Torvalds 370f2f0b00aSOleg Nesterov /* 371f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 37286b6c1f3SDenys Vlasenko * SUID, SGID and LSM creds get determined differently 3735e751e99SDavid Howells * under ptrace. 374d84f4f99SDavid Howells */ 375793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 3769b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 377d84f4f99SDavid Howells goto out; 3784b105cbbSOleg Nesterov 379f5b40e36SLinus Torvalds task_lock(task); 380caaee623SJann Horn retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); 3814b105cbbSOleg Nesterov task_unlock(task); 3821da177e4SLinus Torvalds if (retval) 3834b105cbbSOleg Nesterov goto unlock_creds; 3841da177e4SLinus Torvalds 3854b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 386b79b7ba9SOleg Nesterov retval = -EPERM; 387b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 3884b105cbbSOleg Nesterov goto unlock_tasklist; 389f2f0b00aSOleg Nesterov if (task->ptrace) 3904b105cbbSOleg Nesterov goto unlock_tasklist; 391b79b7ba9SOleg Nesterov 3923544d72aSTejun Heo if (seize) 393aa9147c9SDenys Vlasenko flags |= PT_SEIZED; 394aa9147c9SDenys Vlasenko task->ptrace = flags; 3951da177e4SLinus Torvalds 396c70d9d80SEric W. Biederman ptrace_link(task, current); 3973544d72aSTejun Heo 3983544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 3993544d72aSTejun Heo if (!seize) 400079b22dcSEric W. Biederman send_sig_info(SIGSTOP, SEND_SIG_PRIV, task); 401b79b7ba9SOleg Nesterov 402d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 403d79fdd6dSTejun Heo 404d79fdd6dSTejun Heo /* 40573ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 406d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 407d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 408d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 409d79fdd6dSTejun Heo * for the transition to complete before returning from this 410d79fdd6dSTejun Heo * function. 411d79fdd6dSTejun Heo * 412d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 413d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 414d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 415d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 416d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 417d79fdd6dSTejun Heo * 418d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 419d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 420d79fdd6dSTejun Heo */ 4217dd3db54STejun Heo if (task_is_stopped(task) && 42273ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 423910ffdb1SOleg Nesterov signal_wake_up_state(task, __TASK_STOPPED); 424d79fdd6dSTejun Heo 425d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 426d79fdd6dSTejun Heo 427b79b7ba9SOleg Nesterov retval = 0; 4284b105cbbSOleg Nesterov unlock_tasklist: 4294b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 4304b105cbbSOleg Nesterov unlock_creds: 4319b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 432f5b40e36SLinus Torvalds out: 433f701e5b7SVladimir Zapolskiy if (!retval) { 4347c3b00e0SOleg Nesterov /* 4357c3b00e0SOleg Nesterov * We do not bother to change retval or clear JOBCTL_TRAPPING 4367c3b00e0SOleg Nesterov * if wait_on_bit() was interrupted by SIGKILL. The tracer will 4377c3b00e0SOleg Nesterov * not return to user-mode, it will exit and clear this bit in 4387c3b00e0SOleg Nesterov * __ptrace_unlink() if it wasn't already cleared by the tracee; 4397c3b00e0SOleg Nesterov * and until then nobody can ptrace this task. 4407c3b00e0SOleg Nesterov */ 4417c3b00e0SOleg Nesterov wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); 442f701e5b7SVladimir Zapolskiy proc_ptrace_connector(task, PTRACE_ATTACH); 443f701e5b7SVladimir Zapolskiy } 444f701e5b7SVladimir Zapolskiy 4451da177e4SLinus Torvalds return retval; 4461da177e4SLinus Torvalds } 4471da177e4SLinus Torvalds 448f2f0b00aSOleg Nesterov /** 449f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 450f2f0b00aSOleg Nesterov * 451f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 452f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 453f2f0b00aSOleg Nesterov */ 454e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 455f2f0b00aSOleg Nesterov { 456f2f0b00aSOleg Nesterov int ret = -EPERM; 457f2f0b00aSOleg Nesterov 4584b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 4594b105cbbSOleg Nesterov /* Are we already being traced? */ 460f2f0b00aSOleg Nesterov if (!current->ptrace) { 461f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 462f2f0b00aSOleg Nesterov /* 463f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 464f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 465f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 466f2f0b00aSOleg Nesterov */ 467f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 468f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 469c70d9d80SEric W. Biederman ptrace_link(current, current->real_parent); 470f2f0b00aSOleg Nesterov } 471f2f0b00aSOleg Nesterov } 4724b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 4734b105cbbSOleg Nesterov 474f2f0b00aSOleg Nesterov return ret; 475f2f0b00aSOleg Nesterov } 476f2f0b00aSOleg Nesterov 47739c626aeSOleg Nesterov /* 47839c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 47939c626aeSOleg Nesterov */ 48039c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 48139c626aeSOleg Nesterov { 48239c626aeSOleg Nesterov int ret; 48339c626aeSOleg Nesterov spin_lock(&sigh->siglock); 48439c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 48539c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 48639c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 48739c626aeSOleg Nesterov return ret; 48839c626aeSOleg Nesterov } 48939c626aeSOleg Nesterov 49039c626aeSOleg Nesterov /* 49139c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 49239c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 49339c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 49439c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 49539c626aeSOleg Nesterov * 49639c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 49739c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 49839c626aeSOleg Nesterov * If it should reap itself, return true. 49939c626aeSOleg Nesterov * 500a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 501a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 502a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 503a7f0765eSOleg Nesterov * do_wait(). 50439c626aeSOleg Nesterov */ 50539c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 50639c626aeSOleg Nesterov { 5079843a1e9SOleg Nesterov bool dead; 5089843a1e9SOleg Nesterov 50939c626aeSOleg Nesterov __ptrace_unlink(p); 51039c626aeSOleg Nesterov 5119843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 5129843a1e9SOleg Nesterov return false; 5139843a1e9SOleg Nesterov 5149843a1e9SOleg Nesterov dead = !thread_group_leader(p); 5159843a1e9SOleg Nesterov 5169843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 51739c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 5189843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 519a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 520a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 5219843a1e9SOleg Nesterov dead = true; 52239c626aeSOleg Nesterov } 523a7f0765eSOleg Nesterov } 52439c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 5259843a1e9SOleg Nesterov if (dead) 52639c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 5279843a1e9SOleg Nesterov return dead; 52839c626aeSOleg Nesterov } 52939c626aeSOleg Nesterov 530e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 5311da177e4SLinus Torvalds { 5327ed20e1aSJesper Juhl if (!valid_signal(data)) 5331da177e4SLinus Torvalds return -EIO; 5341da177e4SLinus Torvalds 5351da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 5361da177e4SLinus Torvalds ptrace_disable(child); 5371da177e4SLinus Torvalds 53895c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 53939c626aeSOleg Nesterov /* 54064a4096cSOleg Nesterov * We rely on ptrace_freeze_traced(). It can't be killed and 54164a4096cSOleg Nesterov * untraced by another thread, it can't be a zombie. 54239c626aeSOleg Nesterov */ 54364a4096cSOleg Nesterov WARN_ON(!child->ptrace || child->exit_state); 54464a4096cSOleg Nesterov /* 54564a4096cSOleg Nesterov * tasklist_lock avoids the race with wait_task_stopped(), see 54664a4096cSOleg Nesterov * the comment in ptrace_resume(). 54764a4096cSOleg Nesterov */ 54895c3eb76SOleg Nesterov child->exit_code = data; 54964a4096cSOleg Nesterov __ptrace_detach(current, child); 5501da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 5511da177e4SLinus Torvalds 552f701e5b7SVladimir Zapolskiy proc_ptrace_connector(child, PTRACE_DETACH); 5534576145cSOleg Nesterov 5541da177e4SLinus Torvalds return 0; 5551da177e4SLinus Torvalds } 5561da177e4SLinus Torvalds 55739c626aeSOleg Nesterov /* 558c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 5597c8bd232SOleg Nesterov * for writing. 56039c626aeSOleg Nesterov */ 5617c8bd232SOleg Nesterov void exit_ptrace(struct task_struct *tracer, struct list_head *dead) 56239c626aeSOleg Nesterov { 56339c626aeSOleg Nesterov struct task_struct *p, *n; 564c7e49c14SOleg Nesterov 56539c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 566992fb6e1SOleg Nesterov if (unlikely(p->ptrace & PT_EXITKILL)) 567079b22dcSEric W. Biederman send_sig_info(SIGKILL, SEND_SIG_PRIV, p); 568992fb6e1SOleg Nesterov 56939c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 5707c8bd232SOleg Nesterov list_add(&p->ptrace_entry, dead); 57139c626aeSOleg Nesterov } 57239c626aeSOleg Nesterov } 57339c626aeSOleg Nesterov 5741da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 5751da177e4SLinus Torvalds { 5761da177e4SLinus Torvalds int copied = 0; 5771da177e4SLinus Torvalds 5781da177e4SLinus Torvalds while (len > 0) { 5791da177e4SLinus Torvalds char buf[128]; 5801da177e4SLinus Torvalds int this_len, retval; 5811da177e4SLinus Torvalds 5821da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 58384d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE); 58484d77d3fSEric W. Biederman 5851da177e4SLinus Torvalds if (!retval) { 5861da177e4SLinus Torvalds if (copied) 5871da177e4SLinus Torvalds break; 5881da177e4SLinus Torvalds return -EIO; 5891da177e4SLinus Torvalds } 5901da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 5911da177e4SLinus Torvalds return -EFAULT; 5921da177e4SLinus Torvalds copied += retval; 5931da177e4SLinus Torvalds src += retval; 5941da177e4SLinus Torvalds dst += retval; 5951da177e4SLinus Torvalds len -= retval; 5961da177e4SLinus Torvalds } 5971da177e4SLinus Torvalds return copied; 5981da177e4SLinus Torvalds } 5991da177e4SLinus Torvalds 6001da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 6011da177e4SLinus Torvalds { 6021da177e4SLinus Torvalds int copied = 0; 6031da177e4SLinus Torvalds 6041da177e4SLinus Torvalds while (len > 0) { 6051da177e4SLinus Torvalds char buf[128]; 6061da177e4SLinus Torvalds int this_len, retval; 6071da177e4SLinus Torvalds 6081da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 6091da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 6101da177e4SLinus Torvalds return -EFAULT; 61184d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, dst, buf, this_len, 612f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 6131da177e4SLinus Torvalds if (!retval) { 6141da177e4SLinus Torvalds if (copied) 6151da177e4SLinus Torvalds break; 6161da177e4SLinus Torvalds return -EIO; 6171da177e4SLinus Torvalds } 6181da177e4SLinus Torvalds copied += retval; 6191da177e4SLinus Torvalds src += retval; 6201da177e4SLinus Torvalds dst += retval; 6211da177e4SLinus Torvalds len -= retval; 6221da177e4SLinus Torvalds } 6231da177e4SLinus Torvalds return copied; 6241da177e4SLinus Torvalds } 6251da177e4SLinus Torvalds 6264abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 6271da177e4SLinus Torvalds { 62886b6c1f3SDenys Vlasenko unsigned flags; 62986b6c1f3SDenys Vlasenko 6308c5cf9e5SDenys Vlasenko if (data & ~(unsigned long)PTRACE_O_MASK) 6318c5cf9e5SDenys Vlasenko return -EINVAL; 6328c5cf9e5SDenys Vlasenko 63313c4a901STycho Andersen if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { 63497f2645fSMasahiro Yamada if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || 63597f2645fSMasahiro Yamada !IS_ENABLED(CONFIG_SECCOMP)) 63613c4a901STycho Andersen return -EINVAL; 63713c4a901STycho Andersen 63813c4a901STycho Andersen if (!capable(CAP_SYS_ADMIN)) 63913c4a901STycho Andersen return -EPERM; 64013c4a901STycho Andersen 64113c4a901STycho Andersen if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || 64213c4a901STycho Andersen current->ptrace & PT_SUSPEND_SECCOMP) 64313c4a901STycho Andersen return -EPERM; 64413c4a901STycho Andersen } 64513c4a901STycho Andersen 64686b6c1f3SDenys Vlasenko /* Avoid intermediate state when all opts are cleared */ 64786b6c1f3SDenys Vlasenko flags = child->ptrace; 64886b6c1f3SDenys Vlasenko flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); 64986b6c1f3SDenys Vlasenko flags |= (data << PT_OPT_FLAG_SHIFT); 65086b6c1f3SDenys Vlasenko child->ptrace = flags; 6511da177e4SLinus Torvalds 6528c5cf9e5SDenys Vlasenko return 0; 6531da177e4SLinus Torvalds } 6541da177e4SLinus Torvalds 655ae7795bcSEric W. Biederman static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info) 6561da177e4SLinus Torvalds { 657e4961254SOleg Nesterov unsigned long flags; 6581da177e4SLinus Torvalds int error = -ESRCH; 6591da177e4SLinus Torvalds 660e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 6611da177e4SLinus Torvalds error = -EINVAL; 6621da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 6630752d7bfSEric W. Biederman copy_siginfo(info, child->last_siginfo); 6641da177e4SLinus Torvalds error = 0; 6651da177e4SLinus Torvalds } 666e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 6671da177e4SLinus Torvalds } 6681da177e4SLinus Torvalds return error; 6691da177e4SLinus Torvalds } 6701da177e4SLinus Torvalds 671ae7795bcSEric W. Biederman static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info) 6721da177e4SLinus Torvalds { 673e4961254SOleg Nesterov unsigned long flags; 6741da177e4SLinus Torvalds int error = -ESRCH; 6751da177e4SLinus Torvalds 676e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 6771da177e4SLinus Torvalds error = -EINVAL; 6781da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 6790752d7bfSEric W. Biederman copy_siginfo(child->last_siginfo, info); 6801da177e4SLinus Torvalds error = 0; 6811da177e4SLinus Torvalds } 682e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 6831da177e4SLinus Torvalds } 6841da177e4SLinus Torvalds return error; 6851da177e4SLinus Torvalds } 6861da177e4SLinus Torvalds 68784c751bdSAndrey Vagin static int ptrace_peek_siginfo(struct task_struct *child, 68884c751bdSAndrey Vagin unsigned long addr, 68984c751bdSAndrey Vagin unsigned long data) 69084c751bdSAndrey Vagin { 69184c751bdSAndrey Vagin struct ptrace_peeksiginfo_args arg; 69284c751bdSAndrey Vagin struct sigpending *pending; 69384c751bdSAndrey Vagin struct sigqueue *q; 69484c751bdSAndrey Vagin int ret, i; 69584c751bdSAndrey Vagin 69684c751bdSAndrey Vagin ret = copy_from_user(&arg, (void __user *) addr, 69784c751bdSAndrey Vagin sizeof(struct ptrace_peeksiginfo_args)); 69884c751bdSAndrey Vagin if (ret) 69984c751bdSAndrey Vagin return -EFAULT; 70084c751bdSAndrey Vagin 70184c751bdSAndrey Vagin if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) 70284c751bdSAndrey Vagin return -EINVAL; /* unknown flags */ 70384c751bdSAndrey Vagin 70484c751bdSAndrey Vagin if (arg.nr < 0) 70584c751bdSAndrey Vagin return -EINVAL; 70684c751bdSAndrey Vagin 707f6e2aa91SEric W. Biederman /* Ensure arg.off fits in an unsigned long */ 708f6e2aa91SEric W. Biederman if (arg.off > ULONG_MAX) 709f6e2aa91SEric W. Biederman return 0; 710f6e2aa91SEric W. Biederman 71184c751bdSAndrey Vagin if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) 71284c751bdSAndrey Vagin pending = &child->signal->shared_pending; 71384c751bdSAndrey Vagin else 71484c751bdSAndrey Vagin pending = &child->pending; 71584c751bdSAndrey Vagin 71684c751bdSAndrey Vagin for (i = 0; i < arg.nr; ) { 717ae7795bcSEric W. Biederman kernel_siginfo_t info; 718f6e2aa91SEric W. Biederman unsigned long off = arg.off + i; 719f6e2aa91SEric W. Biederman bool found = false; 72084c751bdSAndrey Vagin 72184c751bdSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 72284c751bdSAndrey Vagin list_for_each_entry(q, &pending->list, list) { 72384c751bdSAndrey Vagin if (!off--) { 724f6e2aa91SEric W. Biederman found = true; 72584c751bdSAndrey Vagin copy_siginfo(&info, &q->info); 72684c751bdSAndrey Vagin break; 72784c751bdSAndrey Vagin } 72884c751bdSAndrey Vagin } 72984c751bdSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 73084c751bdSAndrey Vagin 731f6e2aa91SEric W. Biederman if (!found) /* beyond the end of the list */ 73284c751bdSAndrey Vagin break; 73384c751bdSAndrey Vagin 73484c751bdSAndrey Vagin #ifdef CONFIG_COMPAT 7355c465217SAndy Lutomirski if (unlikely(in_compat_syscall())) { 73684c751bdSAndrey Vagin compat_siginfo_t __user *uinfo = compat_ptr(data); 73784c751bdSAndrey Vagin 738cc731525SEric W. Biederman if (copy_siginfo_to_user32(uinfo, &info)) { 739706b23bdSMathieu Desnoyers ret = -EFAULT; 740706b23bdSMathieu Desnoyers break; 741706b23bdSMathieu Desnoyers } 742706b23bdSMathieu Desnoyers 74384c751bdSAndrey Vagin } else 74484c751bdSAndrey Vagin #endif 74584c751bdSAndrey Vagin { 74684c751bdSAndrey Vagin siginfo_t __user *uinfo = (siginfo_t __user *) data; 74784c751bdSAndrey Vagin 748cc731525SEric W. Biederman if (copy_siginfo_to_user(uinfo, &info)) { 74984c751bdSAndrey Vagin ret = -EFAULT; 75084c751bdSAndrey Vagin break; 75184c751bdSAndrey Vagin } 752706b23bdSMathieu Desnoyers } 75384c751bdSAndrey Vagin 75484c751bdSAndrey Vagin data += sizeof(siginfo_t); 75584c751bdSAndrey Vagin i++; 75684c751bdSAndrey Vagin 75784c751bdSAndrey Vagin if (signal_pending(current)) 75884c751bdSAndrey Vagin break; 75984c751bdSAndrey Vagin 76084c751bdSAndrey Vagin cond_resched(); 76184c751bdSAndrey Vagin } 76284c751bdSAndrey Vagin 76384c751bdSAndrey Vagin if (i > 0) 76484c751bdSAndrey Vagin return i; 76584c751bdSAndrey Vagin 76684c751bdSAndrey Vagin return ret; 76784c751bdSAndrey Vagin } 76836df29d7SRoland McGrath 76936df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 77036df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 77136df29d7SRoland McGrath #else 77236df29d7SRoland McGrath #define is_singlestep(request) 0 77336df29d7SRoland McGrath #endif 77436df29d7SRoland McGrath 7755b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 7765b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 7775b88abbfSRoland McGrath #else 7785b88abbfSRoland McGrath #define is_singleblock(request) 0 7795b88abbfSRoland McGrath #endif 7805b88abbfSRoland McGrath 78136df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 78236df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 78336df29d7SRoland McGrath #else 78436df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 78536df29d7SRoland McGrath #endif 78636df29d7SRoland McGrath 7874abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 7884abf9869SNamhyung Kim unsigned long data) 78936df29d7SRoland McGrath { 790b72c1869SOleg Nesterov bool need_siglock; 791b72c1869SOleg Nesterov 79236df29d7SRoland McGrath if (!valid_signal(data)) 79336df29d7SRoland McGrath return -EIO; 79436df29d7SRoland McGrath 79536df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 79636df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 79736df29d7SRoland McGrath else 79836df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 79936df29d7SRoland McGrath 80036df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 80136df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 80236df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 80336df29d7SRoland McGrath else 80436df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 80536df29d7SRoland McGrath #endif 80636df29d7SRoland McGrath 8075b88abbfSRoland McGrath if (is_singleblock(request)) { 8085b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 8095b88abbfSRoland McGrath return -EIO; 8105b88abbfSRoland McGrath user_enable_block_step(child); 8115b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 81236df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 81336df29d7SRoland McGrath return -EIO; 81436df29d7SRoland McGrath user_enable_single_step(child); 8153a709703SRoland McGrath } else { 81636df29d7SRoland McGrath user_disable_single_step(child); 8173a709703SRoland McGrath } 81836df29d7SRoland McGrath 819b72c1869SOleg Nesterov /* 820b72c1869SOleg Nesterov * Change ->exit_code and ->state under siglock to avoid the race 821b72c1869SOleg Nesterov * with wait_task_stopped() in between; a non-zero ->exit_code will 822b72c1869SOleg Nesterov * wrongly look like another report from tracee. 823b72c1869SOleg Nesterov * 824b72c1869SOleg Nesterov * Note that we need siglock even if ->exit_code == data and/or this 825b72c1869SOleg Nesterov * status was not reported yet, the new status must not be cleared by 826b72c1869SOleg Nesterov * wait_task_stopped() after resume. 827b72c1869SOleg Nesterov * 828b72c1869SOleg Nesterov * If data == 0 we do not care if wait_task_stopped() reports the old 829b72c1869SOleg Nesterov * status and clears the code too; this can't race with the tracee, it 830b72c1869SOleg Nesterov * takes siglock after resume. 831b72c1869SOleg Nesterov */ 832b72c1869SOleg Nesterov need_siglock = data && !thread_group_empty(current); 833b72c1869SOleg Nesterov if (need_siglock) 834b72c1869SOleg Nesterov spin_lock_irq(&child->sighand->siglock); 83536df29d7SRoland McGrath child->exit_code = data; 8360666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 837b72c1869SOleg Nesterov if (need_siglock) 838b72c1869SOleg Nesterov spin_unlock_irq(&child->sighand->siglock); 83936df29d7SRoland McGrath 84036df29d7SRoland McGrath return 0; 84136df29d7SRoland McGrath } 84236df29d7SRoland McGrath 8432225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8442225a122SSuresh Siddha 8452225a122SSuresh Siddha static const struct user_regset * 8462225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 8472225a122SSuresh Siddha { 8482225a122SSuresh Siddha const struct user_regset *regset; 8492225a122SSuresh Siddha int n; 8502225a122SSuresh Siddha 8512225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 8522225a122SSuresh Siddha regset = view->regsets + n; 8532225a122SSuresh Siddha if (regset->core_note_type == type) 8542225a122SSuresh Siddha return regset; 8552225a122SSuresh Siddha } 8562225a122SSuresh Siddha 8572225a122SSuresh Siddha return NULL; 8582225a122SSuresh Siddha } 8592225a122SSuresh Siddha 8602225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 8612225a122SSuresh Siddha struct iovec *kiov) 8622225a122SSuresh Siddha { 8632225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 8642225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 8652225a122SSuresh Siddha int regset_no; 8662225a122SSuresh Siddha 8672225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 868c6a0dd7eSSuresh Siddha return -EINVAL; 8692225a122SSuresh Siddha 8702225a122SSuresh Siddha regset_no = regset - view->regsets; 8712225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 8722225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 8732225a122SSuresh Siddha 8742225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 8752225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 8762225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 8772225a122SSuresh Siddha else 8782225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 8792225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 8802225a122SSuresh Siddha } 8812225a122SSuresh Siddha 882e8440c14SJosh Stone /* 883e8440c14SJosh Stone * This is declared in linux/regset.h and defined in machine-dependent 884e8440c14SJosh Stone * code. We put the export here, near the primary machine-neutral use, 885e8440c14SJosh Stone * to ensure no machine forgets it. 886e8440c14SJosh Stone */ 887e8440c14SJosh Stone EXPORT_SYMBOL_GPL(task_user_regset_view); 8882225a122SSuresh Siddha #endif 8892225a122SSuresh Siddha 8901da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 8914abf9869SNamhyung Kim unsigned long addr, unsigned long data) 8921da177e4SLinus Torvalds { 893fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 8941da177e4SLinus Torvalds int ret = -EIO; 895ae7795bcSEric W. Biederman kernel_siginfo_t siginfo, *si; 8969fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 8979fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 898fca26f26STejun Heo unsigned long flags; 8991da177e4SLinus Torvalds 9001da177e4SLinus Torvalds switch (request) { 90116c3e389SRoland McGrath case PTRACE_PEEKTEXT: 90216c3e389SRoland McGrath case PTRACE_PEEKDATA: 90316c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 90416c3e389SRoland McGrath case PTRACE_POKETEXT: 90516c3e389SRoland McGrath case PTRACE_POKEDATA: 90616c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 90716c3e389SRoland McGrath 9081da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 9091da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 9101da177e4SLinus Torvalds #endif 9111da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 9121da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 9131da177e4SLinus Torvalds break; 9141da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 9159fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 9161da177e4SLinus Torvalds break; 917e16b2781SRoland McGrath 91884c751bdSAndrey Vagin case PTRACE_PEEKSIGINFO: 91984c751bdSAndrey Vagin ret = ptrace_peek_siginfo(child, addr, data); 92084c751bdSAndrey Vagin break; 92184c751bdSAndrey Vagin 9221da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 923e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 924e16b2781SRoland McGrath if (!ret) 9259fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 9261da177e4SLinus Torvalds break; 927e16b2781SRoland McGrath 9281da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 9294cd2e0e7SEric W. Biederman ret = copy_siginfo_from_user(&siginfo, datavp); 9304cd2e0e7SEric W. Biederman if (!ret) 931e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 9321da177e4SLinus Torvalds break; 933e16b2781SRoland McGrath 934fcfc2aa0SAndrei Vagin case PTRACE_GETSIGMASK: { 935fcfc2aa0SAndrei Vagin sigset_t *mask; 936fcfc2aa0SAndrei Vagin 93729000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 93829000caeSAndrey Vagin ret = -EINVAL; 93929000caeSAndrey Vagin break; 94029000caeSAndrey Vagin } 94129000caeSAndrey Vagin 942fcfc2aa0SAndrei Vagin if (test_tsk_restore_sigmask(child)) 943fcfc2aa0SAndrei Vagin mask = &child->saved_sigmask; 944fcfc2aa0SAndrei Vagin else 945fcfc2aa0SAndrei Vagin mask = &child->blocked; 946fcfc2aa0SAndrei Vagin 947fcfc2aa0SAndrei Vagin if (copy_to_user(datavp, mask, sizeof(sigset_t))) 94829000caeSAndrey Vagin ret = -EFAULT; 94929000caeSAndrey Vagin else 95029000caeSAndrey Vagin ret = 0; 95129000caeSAndrey Vagin 95229000caeSAndrey Vagin break; 953fcfc2aa0SAndrei Vagin } 95429000caeSAndrey Vagin 95529000caeSAndrey Vagin case PTRACE_SETSIGMASK: { 95629000caeSAndrey Vagin sigset_t new_set; 95729000caeSAndrey Vagin 95829000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 95929000caeSAndrey Vagin ret = -EINVAL; 96029000caeSAndrey Vagin break; 96129000caeSAndrey Vagin } 96229000caeSAndrey Vagin 96329000caeSAndrey Vagin if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { 96429000caeSAndrey Vagin ret = -EFAULT; 96529000caeSAndrey Vagin break; 96629000caeSAndrey Vagin } 96729000caeSAndrey Vagin 96829000caeSAndrey Vagin sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); 96929000caeSAndrey Vagin 97029000caeSAndrey Vagin /* 97129000caeSAndrey Vagin * Every thread does recalc_sigpending() after resume, so 97229000caeSAndrey Vagin * retarget_shared_pending() and recalc_sigpending() are not 97329000caeSAndrey Vagin * called here. 97429000caeSAndrey Vagin */ 97529000caeSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 97629000caeSAndrey Vagin child->blocked = new_set; 97729000caeSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 97829000caeSAndrey Vagin 979fcfc2aa0SAndrei Vagin clear_tsk_restore_sigmask(child); 980fcfc2aa0SAndrei Vagin 98129000caeSAndrey Vagin ret = 0; 98229000caeSAndrey Vagin break; 98329000caeSAndrey Vagin } 98429000caeSAndrey Vagin 985fca26f26STejun Heo case PTRACE_INTERRUPT: 986fca26f26STejun Heo /* 987fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 988fca26f26STejun Heo * control. At least one trap is guaranteed to happen 989fca26f26STejun Heo * after this request. If @child is already trapped, the 990fca26f26STejun Heo * current trap is not disturbed and another trap will 991fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 992fca26f26STejun Heo * 993fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 994fca26f26STejun Heo * the pending condition is cleared regardless. 995fca26f26STejun Heo */ 996fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 997fca26f26STejun Heo break; 998fca26f26STejun Heo 999544b2c91STejun Heo /* 1000544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 1001544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 1002544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 1003544b2c91STejun Heo * tracee into STOP. 1004544b2c91STejun Heo */ 1005fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 1006910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 1007544b2c91STejun Heo 1008544b2c91STejun Heo unlock_task_sighand(child, &flags); 1009544b2c91STejun Heo ret = 0; 1010544b2c91STejun Heo break; 1011544b2c91STejun Heo 1012544b2c91STejun Heo case PTRACE_LISTEN: 1013544b2c91STejun Heo /* 1014544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 1015544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 1016544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 1017544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 1018544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 1019544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 1020544b2c91STejun Heo */ 1021544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 1022544b2c91STejun Heo break; 1023544b2c91STejun Heo 1024544b2c91STejun Heo si = child->last_siginfo; 1025f9d81f61SOleg Nesterov if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { 1026544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 1027544b2c91STejun Heo /* 1028f9d81f61SOleg Nesterov * If NOTIFY is set, it means event happened between 1029f9d81f61SOleg Nesterov * start of this trap and now. Trigger re-trap. 1030544b2c91STejun Heo */ 1031544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 1032910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 1033fca26f26STejun Heo ret = 0; 1034f9d81f61SOleg Nesterov } 1035f9d81f61SOleg Nesterov unlock_task_sighand(child, &flags); 1036fca26f26STejun Heo break; 1037fca26f26STejun Heo 10381bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 10391bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 10401bcf5482SAlexey Dobriyan break; 104136df29d7SRoland McGrath 10429c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 10439c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 1044e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 10459c1a1259SMike Frysinger unsigned long tmp = 0; 10469c1a1259SMike Frysinger 1047e0129ef9SOleg Nesterov ret = -ESRCH; 1048e0129ef9SOleg Nesterov if (!mm) 1049e0129ef9SOleg Nesterov break; 1050e0129ef9SOleg Nesterov 10519c1a1259SMike Frysinger switch (addr) { 10529c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 1053e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 10549c1a1259SMike Frysinger break; 10559c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 1056e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 10579c1a1259SMike Frysinger break; 10589c1a1259SMike Frysinger default: 10599c1a1259SMike Frysinger break; 10609c1a1259SMike Frysinger } 1061e0129ef9SOleg Nesterov mmput(mm); 10629c1a1259SMike Frysinger 10639fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 10649c1a1259SMike Frysinger break; 10659c1a1259SMike Frysinger } 10669c1a1259SMike Frysinger #endif 10679c1a1259SMike Frysinger 106836df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 106936df29d7SRoland McGrath case PTRACE_SINGLESTEP: 107036df29d7SRoland McGrath #endif 10715b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 10725b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 10735b88abbfSRoland McGrath #endif 107436df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 107536df29d7SRoland McGrath case PTRACE_SYSEMU: 107636df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 107736df29d7SRoland McGrath #endif 107836df29d7SRoland McGrath case PTRACE_SYSCALL: 107936df29d7SRoland McGrath case PTRACE_CONT: 108036df29d7SRoland McGrath return ptrace_resume(child, request, data); 108136df29d7SRoland McGrath 108236df29d7SRoland McGrath case PTRACE_KILL: 108336df29d7SRoland McGrath if (child->exit_state) /* already dead */ 108436df29d7SRoland McGrath return 0; 108536df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 108636df29d7SRoland McGrath 10872225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 10882225a122SSuresh Siddha case PTRACE_GETREGSET: 108929000caeSAndrey Vagin case PTRACE_SETREGSET: { 10902225a122SSuresh Siddha struct iovec kiov; 10919fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 10922225a122SSuresh Siddha 109396d4f267SLinus Torvalds if (!access_ok(uiov, sizeof(*uiov))) 10942225a122SSuresh Siddha return -EFAULT; 10952225a122SSuresh Siddha 10962225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 10972225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 10982225a122SSuresh Siddha return -EFAULT; 10992225a122SSuresh Siddha 11002225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 11012225a122SSuresh Siddha if (!ret) 11022225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 11032225a122SSuresh Siddha break; 11042225a122SSuresh Siddha } 11052225a122SSuresh Siddha #endif 1106f8e529edSTycho Andersen 1107f8e529edSTycho Andersen case PTRACE_SECCOMP_GET_FILTER: 1108f8e529edSTycho Andersen ret = seccomp_get_filter(child, addr, datavp); 1109f8e529edSTycho Andersen break; 1110f8e529edSTycho Andersen 111126500475STycho Andersen case PTRACE_SECCOMP_GET_METADATA: 111226500475STycho Andersen ret = seccomp_get_metadata(child, addr, datavp); 111326500475STycho Andersen break; 111426500475STycho Andersen 11151da177e4SLinus Torvalds default: 11161da177e4SLinus Torvalds break; 11171da177e4SLinus Torvalds } 11181da177e4SLinus Torvalds 11191da177e4SLinus Torvalds return ret; 11201da177e4SLinus Torvalds } 1121481bed45SChristoph Hellwig 11220ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 11230ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 11240ac15559SChristoph Hellwig #endif 11250ac15559SChristoph Hellwig 11264abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 11274abf9869SNamhyung Kim unsigned long, data) 1128481bed45SChristoph Hellwig { 1129481bed45SChristoph Hellwig struct task_struct *child; 1130481bed45SChristoph Hellwig long ret; 1131481bed45SChristoph Hellwig 11326b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 11336b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 11346ea6dd93SHaavard Skinnemoen if (!ret) 11356ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 1136481bed45SChristoph Hellwig goto out; 11376b9c7ed8SChristoph Hellwig } 11386b9c7ed8SChristoph Hellwig 11392ee08260SMike Rapoport child = find_get_task_by_vpid(pid); 11402ee08260SMike Rapoport if (!child) { 11412ee08260SMike Rapoport ret = -ESRCH; 11426b9c7ed8SChristoph Hellwig goto out; 11436b9c7ed8SChristoph Hellwig } 1144481bed45SChristoph Hellwig 11453544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1146aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 11470ac15559SChristoph Hellwig /* 11480ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 11490ac15559SChristoph Hellwig * a ptrace attach. 11500ac15559SChristoph Hellwig */ 11510ac15559SChristoph Hellwig if (!ret) 11520ac15559SChristoph Hellwig arch_ptrace_attach(child); 1153005f18dfSChristoph Hellwig goto out_put_task_struct; 1154481bed45SChristoph Hellwig } 1155481bed45SChristoph Hellwig 1156fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1157fca26f26STejun Heo request == PTRACE_INTERRUPT); 1158481bed45SChristoph Hellwig if (ret < 0) 1159481bed45SChristoph Hellwig goto out_put_task_struct; 1160481bed45SChristoph Hellwig 1161481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 11629899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 11639899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 1164481bed45SChristoph Hellwig 1165481bed45SChristoph Hellwig out_put_task_struct: 1166481bed45SChristoph Hellwig put_task_struct(child); 1167481bed45SChristoph Hellwig out: 1168481bed45SChristoph Hellwig return ret; 1169481bed45SChristoph Hellwig } 117076647323SAlexey Dobriyan 11714abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 11724abf9869SNamhyung Kim unsigned long data) 117376647323SAlexey Dobriyan { 117476647323SAlexey Dobriyan unsigned long tmp; 117576647323SAlexey Dobriyan int copied; 117676647323SAlexey Dobriyan 117784d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); 117876647323SAlexey Dobriyan if (copied != sizeof(tmp)) 117976647323SAlexey Dobriyan return -EIO; 118076647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 118176647323SAlexey Dobriyan } 1182f284ce72SAlexey Dobriyan 11834abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 11844abf9869SNamhyung Kim unsigned long data) 1185f284ce72SAlexey Dobriyan { 1186f284ce72SAlexey Dobriyan int copied; 1187f284ce72SAlexey Dobriyan 118884d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &data, sizeof(data), 1189f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1190f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 1191f284ce72SAlexey Dobriyan } 1192032d82d9SRoland McGrath 119396b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 1194032d82d9SRoland McGrath 1195032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 1196032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 1197032d82d9SRoland McGrath { 1198032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 1199032d82d9SRoland McGrath compat_ulong_t word; 1200ae7795bcSEric W. Biederman kernel_siginfo_t siginfo; 1201032d82d9SRoland McGrath int ret; 1202032d82d9SRoland McGrath 1203032d82d9SRoland McGrath switch (request) { 1204032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 1205032d82d9SRoland McGrath case PTRACE_PEEKDATA: 120684d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &word, sizeof(word), 1207f307ab6dSLorenzo Stoakes FOLL_FORCE); 1208032d82d9SRoland McGrath if (ret != sizeof(word)) 1209032d82d9SRoland McGrath ret = -EIO; 1210032d82d9SRoland McGrath else 1211032d82d9SRoland McGrath ret = put_user(word, datap); 1212032d82d9SRoland McGrath break; 1213032d82d9SRoland McGrath 1214032d82d9SRoland McGrath case PTRACE_POKETEXT: 1215032d82d9SRoland McGrath case PTRACE_POKEDATA: 121684d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &data, sizeof(data), 1217f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1218032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 1219032d82d9SRoland McGrath break; 1220032d82d9SRoland McGrath 1221032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 1222032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 1223032d82d9SRoland McGrath break; 1224032d82d9SRoland McGrath 1225e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 1226e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 1227e16b2781SRoland McGrath if (!ret) 1228e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 1229e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 1230e16b2781SRoland McGrath &siginfo); 1231e16b2781SRoland McGrath break; 1232e16b2781SRoland McGrath 1233e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 12344cd2e0e7SEric W. Biederman ret = copy_siginfo_from_user32( 12354cd2e0e7SEric W. Biederman &siginfo, (struct compat_siginfo __user *) datap); 12364cd2e0e7SEric W. Biederman if (!ret) 1237e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 1238e16b2781SRoland McGrath break; 12392225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 12402225a122SSuresh Siddha case PTRACE_GETREGSET: 12412225a122SSuresh Siddha case PTRACE_SETREGSET: 12422225a122SSuresh Siddha { 12432225a122SSuresh Siddha struct iovec kiov; 12442225a122SSuresh Siddha struct compat_iovec __user *uiov = 12452225a122SSuresh Siddha (struct compat_iovec __user *) datap; 12462225a122SSuresh Siddha compat_uptr_t ptr; 12472225a122SSuresh Siddha compat_size_t len; 12482225a122SSuresh Siddha 124996d4f267SLinus Torvalds if (!access_ok(uiov, sizeof(*uiov))) 12502225a122SSuresh Siddha return -EFAULT; 12512225a122SSuresh Siddha 12522225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 12532225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 12542225a122SSuresh Siddha return -EFAULT; 12552225a122SSuresh Siddha 12562225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 12572225a122SSuresh Siddha kiov.iov_len = len; 12582225a122SSuresh Siddha 12592225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 12602225a122SSuresh Siddha if (!ret) 12612225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 12622225a122SSuresh Siddha break; 12632225a122SSuresh Siddha } 12642225a122SSuresh Siddha #endif 1265e16b2781SRoland McGrath 1266032d82d9SRoland McGrath default: 1267032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 1268032d82d9SRoland McGrath } 1269032d82d9SRoland McGrath 1270032d82d9SRoland McGrath return ret; 1271032d82d9SRoland McGrath } 1272c269f196SRoland McGrath 127362a6fa97SHeiko Carstens COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, 127462a6fa97SHeiko Carstens compat_long_t, addr, compat_long_t, data) 1275c269f196SRoland McGrath { 1276c269f196SRoland McGrath struct task_struct *child; 1277c269f196SRoland McGrath long ret; 1278c269f196SRoland McGrath 1279c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1280c269f196SRoland McGrath ret = ptrace_traceme(); 1281c269f196SRoland McGrath goto out; 1282c269f196SRoland McGrath } 1283c269f196SRoland McGrath 12842ee08260SMike Rapoport child = find_get_task_by_vpid(pid); 12852ee08260SMike Rapoport if (!child) { 12862ee08260SMike Rapoport ret = -ESRCH; 1287c269f196SRoland McGrath goto out; 1288c269f196SRoland McGrath } 1289c269f196SRoland McGrath 12903544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1291aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 1292c269f196SRoland McGrath /* 1293c269f196SRoland McGrath * Some architectures need to do book-keeping after 1294c269f196SRoland McGrath * a ptrace attach. 1295c269f196SRoland McGrath */ 1296c269f196SRoland McGrath if (!ret) 1297c269f196SRoland McGrath arch_ptrace_attach(child); 1298c269f196SRoland McGrath goto out_put_task_struct; 1299c269f196SRoland McGrath } 1300c269f196SRoland McGrath 1301fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1302fca26f26STejun Heo request == PTRACE_INTERRUPT); 13039899d11fSOleg Nesterov if (!ret) { 1304c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 13059899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 13069899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 13079899d11fSOleg Nesterov } 1308c269f196SRoland McGrath 1309c269f196SRoland McGrath out_put_task_struct: 1310c269f196SRoland McGrath put_task_struct(child); 1311c269f196SRoland McGrath out: 1312c269f196SRoland McGrath return ret; 1313c269f196SRoland McGrath } 131496b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1315