1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * linux/kernel/ptrace.c 41da177e4SLinus Torvalds * 51da177e4SLinus Torvalds * (C) Copyright 1999 Linus Torvalds 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * Common interfaces for "ptrace()" which we do not want 81da177e4SLinus Torvalds * to continually duplicate across every architecture. 91da177e4SLinus Torvalds */ 101da177e4SLinus Torvalds 11c59ede7bSRandy.Dunlap #include <linux/capability.h> 129984de1aSPaul Gortmaker #include <linux/export.h> 131da177e4SLinus Torvalds #include <linux/sched.h> 146e84f315SIngo Molnar #include <linux/sched/mm.h> 15f7ccbae4SIngo Molnar #include <linux/sched/coredump.h> 1629930025SIngo Molnar #include <linux/sched/task.h> 171da177e4SLinus Torvalds #include <linux/errno.h> 181da177e4SLinus Torvalds #include <linux/mm.h> 191da177e4SLinus Torvalds #include <linux/highmem.h> 201da177e4SLinus Torvalds #include <linux/pagemap.h> 211da177e4SLinus Torvalds #include <linux/ptrace.h> 221da177e4SLinus Torvalds #include <linux/security.h> 237ed20e1aSJesper Juhl #include <linux/signal.h> 24a27bb332SKent Overstreet #include <linux/uio.h> 25a5cb013dSAl Viro #include <linux/audit.h> 26b488893aSPavel Emelyanov #include <linux/pid_namespace.h> 27f17d30a8SAdrian Bunk #include <linux/syscalls.h> 283a709703SRoland McGrath #include <linux/uaccess.h> 292225a122SSuresh Siddha #include <linux/regset.h> 30bf26c018SFrederic Weisbecker #include <linux/hw_breakpoint.h> 31f701e5b7SVladimir Zapolskiy #include <linux/cn_proc.h> 3284c751bdSAndrey Vagin #include <linux/compat.h> 33fcfc2aa0SAndrei Vagin #include <linux/sched/signal.h> 341da177e4SLinus Torvalds 3584d77d3fSEric W. Biederman /* 3684d77d3fSEric W. Biederman * Access another process' address space via ptrace. 3784d77d3fSEric W. Biederman * Source/target buffer must be kernel space, 3884d77d3fSEric W. Biederman * Do not walk the page table directly, use get_user_pages 3984d77d3fSEric W. Biederman */ 4084d77d3fSEric W. Biederman int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, 4184d77d3fSEric W. Biederman void *buf, int len, unsigned int gup_flags) 4284d77d3fSEric W. Biederman { 4384d77d3fSEric W. Biederman struct mm_struct *mm; 4484d77d3fSEric W. Biederman int ret; 4584d77d3fSEric W. Biederman 4684d77d3fSEric W. Biederman mm = get_task_mm(tsk); 4784d77d3fSEric W. Biederman if (!mm) 4884d77d3fSEric W. Biederman return 0; 4984d77d3fSEric W. Biederman 5084d77d3fSEric W. Biederman if (!tsk->ptrace || 5184d77d3fSEric W. Biederman (current != tsk->parent) || 5284d77d3fSEric W. Biederman ((get_dumpable(mm) != SUID_DUMP_USER) && 5384d77d3fSEric W. Biederman !ptracer_capable(tsk, mm->user_ns))) { 5484d77d3fSEric W. Biederman mmput(mm); 5584d77d3fSEric W. Biederman return 0; 5684d77d3fSEric W. Biederman } 5784d77d3fSEric W. Biederman 5884d77d3fSEric W. Biederman ret = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags); 5984d77d3fSEric W. Biederman mmput(mm); 6084d77d3fSEric W. Biederman 6184d77d3fSEric W. Biederman return ret; 6284d77d3fSEric W. Biederman } 6384d77d3fSEric W. Biederman 64bf53de90SMarkus Metzger 65c70d9d80SEric W. Biederman void __ptrace_link(struct task_struct *child, struct task_struct *new_parent, 66c70d9d80SEric W. Biederman const struct cred *ptracer_cred) 67c70d9d80SEric W. Biederman { 68c70d9d80SEric W. Biederman BUG_ON(!list_empty(&child->ptrace_entry)); 69c70d9d80SEric W. Biederman list_add(&child->ptrace_entry, &new_parent->ptraced); 70c70d9d80SEric W. Biederman child->parent = new_parent; 71c70d9d80SEric W. Biederman child->ptracer_cred = get_cred(ptracer_cred); 72c70d9d80SEric W. Biederman } 73c70d9d80SEric W. Biederman 74bf53de90SMarkus Metzger /* 751da177e4SLinus Torvalds * ptrace a task: make the debugger its new parent and 761da177e4SLinus Torvalds * move it to the ptrace list. 771da177e4SLinus Torvalds * 781da177e4SLinus Torvalds * Must be called with the tasklist lock write-held. 791da177e4SLinus Torvalds */ 80c70d9d80SEric W. Biederman static void ptrace_link(struct task_struct *child, struct task_struct *new_parent) 811da177e4SLinus Torvalds { 8264b875f7SEric W. Biederman rcu_read_lock(); 83c70d9d80SEric W. Biederman __ptrace_link(child, new_parent, __task_cred(new_parent)); 8464b875f7SEric W. Biederman rcu_read_unlock(); 851da177e4SLinus Torvalds } 861da177e4SLinus Torvalds 87e3bd058fSTejun Heo /** 88e3bd058fSTejun Heo * __ptrace_unlink - unlink ptracee and restore its execution state 89e3bd058fSTejun Heo * @child: ptracee to be unlinked 901da177e4SLinus Torvalds * 910e9f0a4aSTejun Heo * Remove @child from the ptrace list, move it back to the original parent, 920e9f0a4aSTejun Heo * and restore the execution state so that it conforms to the group stop 930e9f0a4aSTejun Heo * state. 940e9f0a4aSTejun Heo * 950e9f0a4aSTejun Heo * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer 960e9f0a4aSTejun Heo * exiting. For PTRACE_DETACH, unless the ptracee has been killed between 970e9f0a4aSTejun Heo * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. 980e9f0a4aSTejun Heo * If the ptracer is exiting, the ptracee can be in any state. 990e9f0a4aSTejun Heo * 1000e9f0a4aSTejun Heo * After detach, the ptracee should be in a state which conforms to the 1010e9f0a4aSTejun Heo * group stop. If the group is stopped or in the process of stopping, the 1020e9f0a4aSTejun Heo * ptracee should be put into TASK_STOPPED; otherwise, it should be woken 1030e9f0a4aSTejun Heo * up from TASK_TRACED. 1040e9f0a4aSTejun Heo * 1050e9f0a4aSTejun Heo * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, 1060e9f0a4aSTejun Heo * it goes through TRACED -> RUNNING -> STOPPED transition which is similar 1070e9f0a4aSTejun Heo * to but in the opposite direction of what happens while attaching to a 1080e9f0a4aSTejun Heo * stopped task. However, in this direction, the intermediate RUNNING 1090e9f0a4aSTejun Heo * state is not hidden even from the current ptracer and if it immediately 1100e9f0a4aSTejun Heo * re-attaches and performs a WNOHANG wait(2), it may fail. 111e3bd058fSTejun Heo * 112e3bd058fSTejun Heo * CONTEXT: 113e3bd058fSTejun Heo * write_lock_irq(tasklist_lock) 1141da177e4SLinus Torvalds */ 11536c8b586SIngo Molnar void __ptrace_unlink(struct task_struct *child) 1161da177e4SLinus Torvalds { 11764b875f7SEric W. Biederman const struct cred *old_cred; 1185ecfbae0SOleg Nesterov BUG_ON(!child->ptrace); 1195ecfbae0SOleg Nesterov 1200a5bf409SAles Novak clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 1210a5bf409SAles Novak 1221da177e4SLinus Torvalds child->parent = child->real_parent; 123f470021aSRoland McGrath list_del_init(&child->ptrace_entry); 12464b875f7SEric W. Biederman old_cred = child->ptracer_cred; 12564b875f7SEric W. Biederman child->ptracer_cred = NULL; 12664b875f7SEric W. Biederman put_cred(old_cred); 1271da177e4SLinus Torvalds 1281da177e4SLinus Torvalds spin_lock(&child->sighand->siglock); 1291333ab03SOleg Nesterov child->ptrace = 0; 1301da177e4SLinus Torvalds /* 13173ddff2bSTejun Heo * Clear all pending traps and TRAPPING. TRAPPING should be 13273ddff2bSTejun Heo * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. 13373ddff2bSTejun Heo */ 13473ddff2bSTejun Heo task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); 13573ddff2bSTejun Heo task_clear_jobctl_trapping(child); 13673ddff2bSTejun Heo 13773ddff2bSTejun Heo /* 138a8f072c1STejun Heo * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and 1390e9f0a4aSTejun Heo * @child isn't dead. 1401da177e4SLinus Torvalds */ 1410e9f0a4aSTejun Heo if (!(child->flags & PF_EXITING) && 1420e9f0a4aSTejun Heo (child->signal->flags & SIGNAL_STOP_STOPPED || 1438a88951bSOleg Nesterov child->signal->group_stop_count)) { 144a8f072c1STejun Heo child->jobctl |= JOBCTL_STOP_PENDING; 1450e9f0a4aSTejun Heo 1460e9f0a4aSTejun Heo /* 1478a88951bSOleg Nesterov * This is only possible if this thread was cloned by the 1488a88951bSOleg Nesterov * traced task running in the stopped group, set the signal 1498a88951bSOleg Nesterov * for the future reports. 1508a88951bSOleg Nesterov * FIXME: we should change ptrace_init_task() to handle this 1518a88951bSOleg Nesterov * case. 1528a88951bSOleg Nesterov */ 1538a88951bSOleg Nesterov if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) 1548a88951bSOleg Nesterov child->jobctl |= SIGSTOP; 1558a88951bSOleg Nesterov } 1568a88951bSOleg Nesterov 1578a88951bSOleg Nesterov /* 1580e9f0a4aSTejun Heo * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick 1590e9f0a4aSTejun Heo * @child in the butt. Note that @resume should be used iff @child 1600e9f0a4aSTejun Heo * is in TASK_TRACED; otherwise, we might unduly disrupt 1610e9f0a4aSTejun Heo * TASK_KILLABLE sleeps. 1620e9f0a4aSTejun Heo */ 163a8f072c1STejun Heo if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) 164910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 1650e9f0a4aSTejun Heo 1661da177e4SLinus Torvalds spin_unlock(&child->sighand->siglock); 1671da177e4SLinus Torvalds } 1681da177e4SLinus Torvalds 1699899d11fSOleg Nesterov /* Ensure that nothing can wake it up, even SIGKILL */ 1709899d11fSOleg Nesterov static bool ptrace_freeze_traced(struct task_struct *task) 1719899d11fSOleg Nesterov { 1729899d11fSOleg Nesterov bool ret = false; 1739899d11fSOleg Nesterov 1749899d11fSOleg Nesterov /* Lockless, nobody but us can set this flag */ 1759899d11fSOleg Nesterov if (task->jobctl & JOBCTL_LISTENING) 1769899d11fSOleg Nesterov return ret; 1779899d11fSOleg Nesterov 1789899d11fSOleg Nesterov spin_lock_irq(&task->sighand->siglock); 1799899d11fSOleg Nesterov if (task_is_traced(task) && !__fatal_signal_pending(task)) { 1809899d11fSOleg Nesterov task->state = __TASK_TRACED; 1819899d11fSOleg Nesterov ret = true; 1829899d11fSOleg Nesterov } 1839899d11fSOleg Nesterov spin_unlock_irq(&task->sighand->siglock); 1849899d11fSOleg Nesterov 1859899d11fSOleg Nesterov return ret; 1869899d11fSOleg Nesterov } 1879899d11fSOleg Nesterov 1889899d11fSOleg Nesterov static void ptrace_unfreeze_traced(struct task_struct *task) 1899899d11fSOleg Nesterov { 1909899d11fSOleg Nesterov if (task->state != __TASK_TRACED) 1919899d11fSOleg Nesterov return; 1929899d11fSOleg Nesterov 1939899d11fSOleg Nesterov WARN_ON(!task->ptrace || task->parent != current); 1949899d11fSOleg Nesterov 1955402e97aSbsegall@google.com /* 1965402e97aSbsegall@google.com * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely. 1975402e97aSbsegall@google.com * Recheck state under the lock to close this race. 1985402e97aSbsegall@google.com */ 1999899d11fSOleg Nesterov spin_lock_irq(&task->sighand->siglock); 2005402e97aSbsegall@google.com if (task->state == __TASK_TRACED) { 2019899d11fSOleg Nesterov if (__fatal_signal_pending(task)) 2029899d11fSOleg Nesterov wake_up_state(task, __TASK_TRACED); 2039899d11fSOleg Nesterov else 2049899d11fSOleg Nesterov task->state = TASK_TRACED; 2055402e97aSbsegall@google.com } 2069899d11fSOleg Nesterov spin_unlock_irq(&task->sighand->siglock); 2079899d11fSOleg Nesterov } 2089899d11fSOleg Nesterov 209755e276bSTejun Heo /** 210755e276bSTejun Heo * ptrace_check_attach - check whether ptracee is ready for ptrace operation 211755e276bSTejun Heo * @child: ptracee to check for 212755e276bSTejun Heo * @ignore_state: don't check whether @child is currently %TASK_TRACED 213755e276bSTejun Heo * 214755e276bSTejun Heo * Check whether @child is being ptraced by %current and ready for further 215755e276bSTejun Heo * ptrace operations. If @ignore_state is %false, @child also should be in 216755e276bSTejun Heo * %TASK_TRACED state and on return the child is guaranteed to be traced 217755e276bSTejun Heo * and not executing. If @ignore_state is %true, @child can be in any 218755e276bSTejun Heo * state. 219755e276bSTejun Heo * 220755e276bSTejun Heo * CONTEXT: 221755e276bSTejun Heo * Grabs and releases tasklist_lock and @child->sighand->siglock. 222755e276bSTejun Heo * 223755e276bSTejun Heo * RETURNS: 224755e276bSTejun Heo * 0 on success, -ESRCH if %child is not ready. 2251da177e4SLinus Torvalds */ 226edea0d03SOleg Nesterov static int ptrace_check_attach(struct task_struct *child, bool ignore_state) 2271da177e4SLinus Torvalds { 2281da177e4SLinus Torvalds int ret = -ESRCH; 2291da177e4SLinus Torvalds 2301da177e4SLinus Torvalds /* 2311da177e4SLinus Torvalds * We take the read lock around doing both checks to close a 2321da177e4SLinus Torvalds * possible race where someone else was tracing our child and 2331da177e4SLinus Torvalds * detached between these two checks. After this locked check, 2341da177e4SLinus Torvalds * we are sure that this is our traced child and that can only 2351da177e4SLinus Torvalds * be changed by us so it's not changing right after this. 2361da177e4SLinus Torvalds */ 2371da177e4SLinus Torvalds read_lock(&tasklist_lock); 2389899d11fSOleg Nesterov if (child->ptrace && child->parent == current) { 2399899d11fSOleg Nesterov WARN_ON(child->state == __TASK_TRACED); 240c0c0b649SOleg Nesterov /* 241c0c0b649SOleg Nesterov * child->sighand can't be NULL, release_task() 242c0c0b649SOleg Nesterov * does ptrace_unlink() before __exit_signal(). 243c0c0b649SOleg Nesterov */ 2449899d11fSOleg Nesterov if (ignore_state || ptrace_freeze_traced(child)) 245321fb561SOleg Nesterov ret = 0; 2461da177e4SLinus Torvalds } 2471da177e4SLinus Torvalds read_unlock(&tasklist_lock); 2481da177e4SLinus Torvalds 2499899d11fSOleg Nesterov if (!ret && !ignore_state) { 2509899d11fSOleg Nesterov if (!wait_task_inactive(child, __TASK_TRACED)) { 2519899d11fSOleg Nesterov /* 2529899d11fSOleg Nesterov * This can only happen if may_ptrace_stop() fails and 2539899d11fSOleg Nesterov * ptrace_stop() changes ->state back to TASK_RUNNING, 2549899d11fSOleg Nesterov * so we should not worry about leaking __TASK_TRACED. 2559899d11fSOleg Nesterov */ 2569899d11fSOleg Nesterov WARN_ON(child->state == __TASK_TRACED); 2579899d11fSOleg Nesterov ret = -ESRCH; 2589899d11fSOleg Nesterov } 2599899d11fSOleg Nesterov } 2601da177e4SLinus Torvalds 2611da177e4SLinus Torvalds return ret; 2621da177e4SLinus Torvalds } 2631da177e4SLinus Torvalds 26469f594a3SEric Paris static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) 26569f594a3SEric Paris { 26669f594a3SEric Paris if (mode & PTRACE_MODE_NOAUDIT) 26769f594a3SEric Paris return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); 26869f594a3SEric Paris else 26969f594a3SEric Paris return has_ns_capability(current, ns, CAP_SYS_PTRACE); 27069f594a3SEric Paris } 27169f594a3SEric Paris 2729f99798fSTetsuo Handa /* Returns 0 on success, -errno on denial. */ 2739f99798fSTetsuo Handa static int __ptrace_may_access(struct task_struct *task, unsigned int mode) 274ab8d11beSMiklos Szeredi { 275c69e8d9cSDavid Howells const struct cred *cred = current_cred(), *tcred; 276bfedb589SEric W. Biederman struct mm_struct *mm; 277caaee623SJann Horn kuid_t caller_uid; 278caaee623SJann Horn kgid_t caller_gid; 279caaee623SJann Horn 280caaee623SJann Horn if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { 281caaee623SJann Horn WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); 282caaee623SJann Horn return -EPERM; 283caaee623SJann Horn } 284b6dff3ecSDavid Howells 285df26c40eSEric W. Biederman /* May we inspect the given task? 286df26c40eSEric W. Biederman * This check is used both for attaching with ptrace 287df26c40eSEric W. Biederman * and for allowing access to sensitive information in /proc. 288df26c40eSEric W. Biederman * 289df26c40eSEric W. Biederman * ptrace_attach denies several cases that /proc allows 290df26c40eSEric W. Biederman * because setting up the necessary parent/child relationship 291df26c40eSEric W. Biederman * or halting the specified task is impossible. 292df26c40eSEric W. Biederman */ 293caaee623SJann Horn 294df26c40eSEric W. Biederman /* Don't let security modules deny introspection */ 29573af963fSMark Grondona if (same_thread_group(task, current)) 296df26c40eSEric W. Biederman return 0; 297c69e8d9cSDavid Howells rcu_read_lock(); 298caaee623SJann Horn if (mode & PTRACE_MODE_FSCREDS) { 299caaee623SJann Horn caller_uid = cred->fsuid; 300caaee623SJann Horn caller_gid = cred->fsgid; 301caaee623SJann Horn } else { 302caaee623SJann Horn /* 303caaee623SJann Horn * Using the euid would make more sense here, but something 304caaee623SJann Horn * in userland might rely on the old behavior, and this 305caaee623SJann Horn * shouldn't be a security problem since 306caaee623SJann Horn * PTRACE_MODE_REALCREDS implies that the caller explicitly 307caaee623SJann Horn * used a syscall that requests access to another process 308caaee623SJann Horn * (and not a filesystem syscall to procfs). 309caaee623SJann Horn */ 310caaee623SJann Horn caller_uid = cred->uid; 311caaee623SJann Horn caller_gid = cred->gid; 312caaee623SJann Horn } 313c69e8d9cSDavid Howells tcred = __task_cred(task); 314caaee623SJann Horn if (uid_eq(caller_uid, tcred->euid) && 315caaee623SJann Horn uid_eq(caller_uid, tcred->suid) && 316caaee623SJann Horn uid_eq(caller_uid, tcred->uid) && 317caaee623SJann Horn gid_eq(caller_gid, tcred->egid) && 318caaee623SJann Horn gid_eq(caller_gid, tcred->sgid) && 319caaee623SJann Horn gid_eq(caller_gid, tcred->gid)) 3208409cca7SSerge E. Hallyn goto ok; 321c4a4d603SEric W. Biederman if (ptrace_has_cap(tcred->user_ns, mode)) 3228409cca7SSerge E. Hallyn goto ok; 323c69e8d9cSDavid Howells rcu_read_unlock(); 324ab8d11beSMiklos Szeredi return -EPERM; 3258409cca7SSerge E. Hallyn ok: 326c69e8d9cSDavid Howells rcu_read_unlock(); 327bfedb589SEric W. Biederman mm = task->mm; 328bfedb589SEric W. Biederman if (mm && 329bfedb589SEric W. Biederman ((get_dumpable(mm) != SUID_DUMP_USER) && 330bfedb589SEric W. Biederman !ptrace_has_cap(mm->user_ns, mode))) 331ab8d11beSMiklos Szeredi return -EPERM; 332ab8d11beSMiklos Szeredi 3339e48858fSIngo Molnar return security_ptrace_access_check(task, mode); 334ab8d11beSMiklos Szeredi } 335ab8d11beSMiklos Szeredi 336006ebb40SStephen Smalley bool ptrace_may_access(struct task_struct *task, unsigned int mode) 337ab8d11beSMiklos Szeredi { 338ab8d11beSMiklos Szeredi int err; 339ab8d11beSMiklos Szeredi task_lock(task); 340006ebb40SStephen Smalley err = __ptrace_may_access(task, mode); 341ab8d11beSMiklos Szeredi task_unlock(task); 3423a709703SRoland McGrath return !err; 343ab8d11beSMiklos Szeredi } 344ab8d11beSMiklos Szeredi 3453544d72aSTejun Heo static int ptrace_attach(struct task_struct *task, long request, 346aa9147c9SDenys Vlasenko unsigned long addr, 3473544d72aSTejun Heo unsigned long flags) 3481da177e4SLinus Torvalds { 3493544d72aSTejun Heo bool seize = (request == PTRACE_SEIZE); 3501da177e4SLinus Torvalds int retval; 351f5b40e36SLinus Torvalds 3523544d72aSTejun Heo retval = -EIO; 353aa9147c9SDenys Vlasenko if (seize) { 354aa9147c9SDenys Vlasenko if (addr != 0) 3553544d72aSTejun Heo goto out; 356aa9147c9SDenys Vlasenko if (flags & ~(unsigned long)PTRACE_O_MASK) 357aa9147c9SDenys Vlasenko goto out; 358aa9147c9SDenys Vlasenko flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); 359aa9147c9SDenys Vlasenko } else { 360aa9147c9SDenys Vlasenko flags = PT_PTRACED; 361aa9147c9SDenys Vlasenko } 3623544d72aSTejun Heo 363a5cb013dSAl Viro audit_ptrace(task); 364a5cb013dSAl Viro 3651da177e4SLinus Torvalds retval = -EPERM; 366b79b7ba9SOleg Nesterov if (unlikely(task->flags & PF_KTHREAD)) 367b79b7ba9SOleg Nesterov goto out; 368bac0abd6SPavel Emelyanov if (same_thread_group(task, current)) 369f5b40e36SLinus Torvalds goto out; 370f5b40e36SLinus Torvalds 371f2f0b00aSOleg Nesterov /* 372f2f0b00aSOleg Nesterov * Protect exec's credential calculations against our interference; 37386b6c1f3SDenys Vlasenko * SUID, SGID and LSM creds get determined differently 3745e751e99SDavid Howells * under ptrace. 375d84f4f99SDavid Howells */ 376793285fcSOleg Nesterov retval = -ERESTARTNOINTR; 3779b1bf12dSKOSAKI Motohiro if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) 378d84f4f99SDavid Howells goto out; 3794b105cbbSOleg Nesterov 380f5b40e36SLinus Torvalds task_lock(task); 381caaee623SJann Horn retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); 3824b105cbbSOleg Nesterov task_unlock(task); 3831da177e4SLinus Torvalds if (retval) 3844b105cbbSOleg Nesterov goto unlock_creds; 3851da177e4SLinus Torvalds 3864b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 387b79b7ba9SOleg Nesterov retval = -EPERM; 388b79b7ba9SOleg Nesterov if (unlikely(task->exit_state)) 3894b105cbbSOleg Nesterov goto unlock_tasklist; 390f2f0b00aSOleg Nesterov if (task->ptrace) 3914b105cbbSOleg Nesterov goto unlock_tasklist; 392b79b7ba9SOleg Nesterov 3933544d72aSTejun Heo if (seize) 394aa9147c9SDenys Vlasenko flags |= PT_SEIZED; 395aa9147c9SDenys Vlasenko task->ptrace = flags; 3961da177e4SLinus Torvalds 397c70d9d80SEric W. Biederman ptrace_link(task, current); 3983544d72aSTejun Heo 3993544d72aSTejun Heo /* SEIZE doesn't trap tracee on attach */ 4003544d72aSTejun Heo if (!seize) 401079b22dcSEric W. Biederman send_sig_info(SIGSTOP, SEND_SIG_PRIV, task); 402b79b7ba9SOleg Nesterov 403d79fdd6dSTejun Heo spin_lock(&task->sighand->siglock); 404d79fdd6dSTejun Heo 405d79fdd6dSTejun Heo /* 40673ddff2bSTejun Heo * If the task is already STOPPED, set JOBCTL_TRAP_STOP and 407d79fdd6dSTejun Heo * TRAPPING, and kick it so that it transits to TRACED. TRAPPING 408d79fdd6dSTejun Heo * will be cleared if the child completes the transition or any 409d79fdd6dSTejun Heo * event which clears the group stop states happens. We'll wait 410d79fdd6dSTejun Heo * for the transition to complete before returning from this 411d79fdd6dSTejun Heo * function. 412d79fdd6dSTejun Heo * 413d79fdd6dSTejun Heo * This hides STOPPED -> RUNNING -> TRACED transition from the 414d79fdd6dSTejun Heo * attaching thread but a different thread in the same group can 415d79fdd6dSTejun Heo * still observe the transient RUNNING state. IOW, if another 416d79fdd6dSTejun Heo * thread's WNOHANG wait(2) on the stopped tracee races against 417d79fdd6dSTejun Heo * ATTACH, the wait(2) may fail due to the transient RUNNING. 418d79fdd6dSTejun Heo * 419d79fdd6dSTejun Heo * The following task_is_stopped() test is safe as both transitions 420d79fdd6dSTejun Heo * in and out of STOPPED are protected by siglock. 421d79fdd6dSTejun Heo */ 4227dd3db54STejun Heo if (task_is_stopped(task) && 42373ddff2bSTejun Heo task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) 424910ffdb1SOleg Nesterov signal_wake_up_state(task, __TASK_STOPPED); 425d79fdd6dSTejun Heo 426d79fdd6dSTejun Heo spin_unlock(&task->sighand->siglock); 427d79fdd6dSTejun Heo 428b79b7ba9SOleg Nesterov retval = 0; 4294b105cbbSOleg Nesterov unlock_tasklist: 4304b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 4314b105cbbSOleg Nesterov unlock_creds: 4329b1bf12dSKOSAKI Motohiro mutex_unlock(&task->signal->cred_guard_mutex); 433f5b40e36SLinus Torvalds out: 434f701e5b7SVladimir Zapolskiy if (!retval) { 4357c3b00e0SOleg Nesterov /* 4367c3b00e0SOleg Nesterov * We do not bother to change retval or clear JOBCTL_TRAPPING 4377c3b00e0SOleg Nesterov * if wait_on_bit() was interrupted by SIGKILL. The tracer will 4387c3b00e0SOleg Nesterov * not return to user-mode, it will exit and clear this bit in 4397c3b00e0SOleg Nesterov * __ptrace_unlink() if it wasn't already cleared by the tracee; 4407c3b00e0SOleg Nesterov * and until then nobody can ptrace this task. 4417c3b00e0SOleg Nesterov */ 4427c3b00e0SOleg Nesterov wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); 443f701e5b7SVladimir Zapolskiy proc_ptrace_connector(task, PTRACE_ATTACH); 444f701e5b7SVladimir Zapolskiy } 445f701e5b7SVladimir Zapolskiy 4461da177e4SLinus Torvalds return retval; 4471da177e4SLinus Torvalds } 4481da177e4SLinus Torvalds 449f2f0b00aSOleg Nesterov /** 450f2f0b00aSOleg Nesterov * ptrace_traceme -- helper for PTRACE_TRACEME 451f2f0b00aSOleg Nesterov * 452f2f0b00aSOleg Nesterov * Performs checks and sets PT_PTRACED. 453f2f0b00aSOleg Nesterov * Should be used by all ptrace implementations for PTRACE_TRACEME. 454f2f0b00aSOleg Nesterov */ 455e3e89cc5SLinus Torvalds static int ptrace_traceme(void) 456f2f0b00aSOleg Nesterov { 457f2f0b00aSOleg Nesterov int ret = -EPERM; 458f2f0b00aSOleg Nesterov 4594b105cbbSOleg Nesterov write_lock_irq(&tasklist_lock); 4604b105cbbSOleg Nesterov /* Are we already being traced? */ 461f2f0b00aSOleg Nesterov if (!current->ptrace) { 462f2f0b00aSOleg Nesterov ret = security_ptrace_traceme(current->parent); 463f2f0b00aSOleg Nesterov /* 464f2f0b00aSOleg Nesterov * Check PF_EXITING to ensure ->real_parent has not passed 465f2f0b00aSOleg Nesterov * exit_ptrace(). Otherwise we don't report the error but 466f2f0b00aSOleg Nesterov * pretend ->real_parent untraces us right after return. 467f2f0b00aSOleg Nesterov */ 468f2f0b00aSOleg Nesterov if (!ret && !(current->real_parent->flags & PF_EXITING)) { 469f2f0b00aSOleg Nesterov current->ptrace = PT_PTRACED; 470c70d9d80SEric W. Biederman ptrace_link(current, current->real_parent); 471f2f0b00aSOleg Nesterov } 472f2f0b00aSOleg Nesterov } 4734b105cbbSOleg Nesterov write_unlock_irq(&tasklist_lock); 4744b105cbbSOleg Nesterov 475f2f0b00aSOleg Nesterov return ret; 476f2f0b00aSOleg Nesterov } 477f2f0b00aSOleg Nesterov 47839c626aeSOleg Nesterov /* 47939c626aeSOleg Nesterov * Called with irqs disabled, returns true if childs should reap themselves. 48039c626aeSOleg Nesterov */ 48139c626aeSOleg Nesterov static int ignoring_children(struct sighand_struct *sigh) 48239c626aeSOleg Nesterov { 48339c626aeSOleg Nesterov int ret; 48439c626aeSOleg Nesterov spin_lock(&sigh->siglock); 48539c626aeSOleg Nesterov ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || 48639c626aeSOleg Nesterov (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); 48739c626aeSOleg Nesterov spin_unlock(&sigh->siglock); 48839c626aeSOleg Nesterov return ret; 48939c626aeSOleg Nesterov } 49039c626aeSOleg Nesterov 49139c626aeSOleg Nesterov /* 49239c626aeSOleg Nesterov * Called with tasklist_lock held for writing. 49339c626aeSOleg Nesterov * Unlink a traced task, and clean it up if it was a traced zombie. 49439c626aeSOleg Nesterov * Return true if it needs to be reaped with release_task(). 49539c626aeSOleg Nesterov * (We can't call release_task() here because we already hold tasklist_lock.) 49639c626aeSOleg Nesterov * 49739c626aeSOleg Nesterov * If it's a zombie, our attachedness prevented normal parent notification 49839c626aeSOleg Nesterov * or self-reaping. Do notification now if it would have happened earlier. 49939c626aeSOleg Nesterov * If it should reap itself, return true. 50039c626aeSOleg Nesterov * 501a7f0765eSOleg Nesterov * If it's our own child, there is no notification to do. But if our normal 502a7f0765eSOleg Nesterov * children self-reap, then this child was prevented by ptrace and we must 503a7f0765eSOleg Nesterov * reap it now, in that case we must also wake up sub-threads sleeping in 504a7f0765eSOleg Nesterov * do_wait(). 50539c626aeSOleg Nesterov */ 50639c626aeSOleg Nesterov static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) 50739c626aeSOleg Nesterov { 5089843a1e9SOleg Nesterov bool dead; 5099843a1e9SOleg Nesterov 51039c626aeSOleg Nesterov __ptrace_unlink(p); 51139c626aeSOleg Nesterov 5129843a1e9SOleg Nesterov if (p->exit_state != EXIT_ZOMBIE) 5139843a1e9SOleg Nesterov return false; 5149843a1e9SOleg Nesterov 5159843a1e9SOleg Nesterov dead = !thread_group_leader(p); 5169843a1e9SOleg Nesterov 5179843a1e9SOleg Nesterov if (!dead && thread_group_empty(p)) { 51839c626aeSOleg Nesterov if (!same_thread_group(p->real_parent, tracer)) 5199843a1e9SOleg Nesterov dead = do_notify_parent(p, p->exit_signal); 520a7f0765eSOleg Nesterov else if (ignoring_children(tracer->sighand)) { 521a7f0765eSOleg Nesterov __wake_up_parent(p, tracer); 5229843a1e9SOleg Nesterov dead = true; 52339c626aeSOleg Nesterov } 524a7f0765eSOleg Nesterov } 52539c626aeSOleg Nesterov /* Mark it as in the process of being reaped. */ 5269843a1e9SOleg Nesterov if (dead) 52739c626aeSOleg Nesterov p->exit_state = EXIT_DEAD; 5289843a1e9SOleg Nesterov return dead; 52939c626aeSOleg Nesterov } 53039c626aeSOleg Nesterov 531e3e89cc5SLinus Torvalds static int ptrace_detach(struct task_struct *child, unsigned int data) 5321da177e4SLinus Torvalds { 5337ed20e1aSJesper Juhl if (!valid_signal(data)) 5341da177e4SLinus Torvalds return -EIO; 5351da177e4SLinus Torvalds 5361da177e4SLinus Torvalds /* Architecture-specific hardware disable .. */ 5371da177e4SLinus Torvalds ptrace_disable(child); 5381da177e4SLinus Torvalds 53995c3eb76SOleg Nesterov write_lock_irq(&tasklist_lock); 54039c626aeSOleg Nesterov /* 54164a4096cSOleg Nesterov * We rely on ptrace_freeze_traced(). It can't be killed and 54264a4096cSOleg Nesterov * untraced by another thread, it can't be a zombie. 54339c626aeSOleg Nesterov */ 54464a4096cSOleg Nesterov WARN_ON(!child->ptrace || child->exit_state); 54564a4096cSOleg Nesterov /* 54664a4096cSOleg Nesterov * tasklist_lock avoids the race with wait_task_stopped(), see 54764a4096cSOleg Nesterov * the comment in ptrace_resume(). 54864a4096cSOleg Nesterov */ 54995c3eb76SOleg Nesterov child->exit_code = data; 55064a4096cSOleg Nesterov __ptrace_detach(current, child); 5511da177e4SLinus Torvalds write_unlock_irq(&tasklist_lock); 5521da177e4SLinus Torvalds 553f701e5b7SVladimir Zapolskiy proc_ptrace_connector(child, PTRACE_DETACH); 5544576145cSOleg Nesterov 5551da177e4SLinus Torvalds return 0; 5561da177e4SLinus Torvalds } 5571da177e4SLinus Torvalds 55839c626aeSOleg Nesterov /* 559c7e49c14SOleg Nesterov * Detach all tasks we were using ptrace on. Called with tasklist held 5607c8bd232SOleg Nesterov * for writing. 56139c626aeSOleg Nesterov */ 5627c8bd232SOleg Nesterov void exit_ptrace(struct task_struct *tracer, struct list_head *dead) 56339c626aeSOleg Nesterov { 56439c626aeSOleg Nesterov struct task_struct *p, *n; 565c7e49c14SOleg Nesterov 56639c626aeSOleg Nesterov list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { 567992fb6e1SOleg Nesterov if (unlikely(p->ptrace & PT_EXITKILL)) 568079b22dcSEric W. Biederman send_sig_info(SIGKILL, SEND_SIG_PRIV, p); 569992fb6e1SOleg Nesterov 57039c626aeSOleg Nesterov if (__ptrace_detach(tracer, p)) 5717c8bd232SOleg Nesterov list_add(&p->ptrace_entry, dead); 57239c626aeSOleg Nesterov } 57339c626aeSOleg Nesterov } 57439c626aeSOleg Nesterov 5751da177e4SLinus Torvalds int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) 5761da177e4SLinus Torvalds { 5771da177e4SLinus Torvalds int copied = 0; 5781da177e4SLinus Torvalds 5791da177e4SLinus Torvalds while (len > 0) { 5801da177e4SLinus Torvalds char buf[128]; 5811da177e4SLinus Torvalds int this_len, retval; 5821da177e4SLinus Torvalds 5831da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 58484d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE); 58584d77d3fSEric W. Biederman 5861da177e4SLinus Torvalds if (!retval) { 5871da177e4SLinus Torvalds if (copied) 5881da177e4SLinus Torvalds break; 5891da177e4SLinus Torvalds return -EIO; 5901da177e4SLinus Torvalds } 5911da177e4SLinus Torvalds if (copy_to_user(dst, buf, retval)) 5921da177e4SLinus Torvalds return -EFAULT; 5931da177e4SLinus Torvalds copied += retval; 5941da177e4SLinus Torvalds src += retval; 5951da177e4SLinus Torvalds dst += retval; 5961da177e4SLinus Torvalds len -= retval; 5971da177e4SLinus Torvalds } 5981da177e4SLinus Torvalds return copied; 5991da177e4SLinus Torvalds } 6001da177e4SLinus Torvalds 6011da177e4SLinus Torvalds int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) 6021da177e4SLinus Torvalds { 6031da177e4SLinus Torvalds int copied = 0; 6041da177e4SLinus Torvalds 6051da177e4SLinus Torvalds while (len > 0) { 6061da177e4SLinus Torvalds char buf[128]; 6071da177e4SLinus Torvalds int this_len, retval; 6081da177e4SLinus Torvalds 6091da177e4SLinus Torvalds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; 6101da177e4SLinus Torvalds if (copy_from_user(buf, src, this_len)) 6111da177e4SLinus Torvalds return -EFAULT; 61284d77d3fSEric W. Biederman retval = ptrace_access_vm(tsk, dst, buf, this_len, 613f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 6141da177e4SLinus Torvalds if (!retval) { 6151da177e4SLinus Torvalds if (copied) 6161da177e4SLinus Torvalds break; 6171da177e4SLinus Torvalds return -EIO; 6181da177e4SLinus Torvalds } 6191da177e4SLinus Torvalds copied += retval; 6201da177e4SLinus Torvalds src += retval; 6211da177e4SLinus Torvalds dst += retval; 6221da177e4SLinus Torvalds len -= retval; 6231da177e4SLinus Torvalds } 6241da177e4SLinus Torvalds return copied; 6251da177e4SLinus Torvalds } 6261da177e4SLinus Torvalds 6274abf9869SNamhyung Kim static int ptrace_setoptions(struct task_struct *child, unsigned long data) 6281da177e4SLinus Torvalds { 62986b6c1f3SDenys Vlasenko unsigned flags; 63086b6c1f3SDenys Vlasenko 6318c5cf9e5SDenys Vlasenko if (data & ~(unsigned long)PTRACE_O_MASK) 6328c5cf9e5SDenys Vlasenko return -EINVAL; 6338c5cf9e5SDenys Vlasenko 63413c4a901STycho Andersen if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { 63597f2645fSMasahiro Yamada if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) || 63697f2645fSMasahiro Yamada !IS_ENABLED(CONFIG_SECCOMP)) 63713c4a901STycho Andersen return -EINVAL; 63813c4a901STycho Andersen 63913c4a901STycho Andersen if (!capable(CAP_SYS_ADMIN)) 64013c4a901STycho Andersen return -EPERM; 64113c4a901STycho Andersen 64213c4a901STycho Andersen if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED || 64313c4a901STycho Andersen current->ptrace & PT_SUSPEND_SECCOMP) 64413c4a901STycho Andersen return -EPERM; 64513c4a901STycho Andersen } 64613c4a901STycho Andersen 64786b6c1f3SDenys Vlasenko /* Avoid intermediate state when all opts are cleared */ 64886b6c1f3SDenys Vlasenko flags = child->ptrace; 64986b6c1f3SDenys Vlasenko flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); 65086b6c1f3SDenys Vlasenko flags |= (data << PT_OPT_FLAG_SHIFT); 65186b6c1f3SDenys Vlasenko child->ptrace = flags; 6521da177e4SLinus Torvalds 6538c5cf9e5SDenys Vlasenko return 0; 6541da177e4SLinus Torvalds } 6551da177e4SLinus Torvalds 656ae7795bcSEric W. Biederman static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info) 6571da177e4SLinus Torvalds { 658e4961254SOleg Nesterov unsigned long flags; 6591da177e4SLinus Torvalds int error = -ESRCH; 6601da177e4SLinus Torvalds 661e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 6621da177e4SLinus Torvalds error = -EINVAL; 6631da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 6640752d7bfSEric W. Biederman copy_siginfo(info, child->last_siginfo); 6651da177e4SLinus Torvalds error = 0; 6661da177e4SLinus Torvalds } 667e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 6681da177e4SLinus Torvalds } 6691da177e4SLinus Torvalds return error; 6701da177e4SLinus Torvalds } 6711da177e4SLinus Torvalds 672ae7795bcSEric W. Biederman static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info) 6731da177e4SLinus Torvalds { 674e4961254SOleg Nesterov unsigned long flags; 6751da177e4SLinus Torvalds int error = -ESRCH; 6761da177e4SLinus Torvalds 677e4961254SOleg Nesterov if (lock_task_sighand(child, &flags)) { 6781da177e4SLinus Torvalds error = -EINVAL; 6791da177e4SLinus Torvalds if (likely(child->last_siginfo != NULL)) { 6800752d7bfSEric W. Biederman copy_siginfo(child->last_siginfo, info); 6811da177e4SLinus Torvalds error = 0; 6821da177e4SLinus Torvalds } 683e4961254SOleg Nesterov unlock_task_sighand(child, &flags); 6841da177e4SLinus Torvalds } 6851da177e4SLinus Torvalds return error; 6861da177e4SLinus Torvalds } 6871da177e4SLinus Torvalds 68884c751bdSAndrey Vagin static int ptrace_peek_siginfo(struct task_struct *child, 68984c751bdSAndrey Vagin unsigned long addr, 69084c751bdSAndrey Vagin unsigned long data) 69184c751bdSAndrey Vagin { 69284c751bdSAndrey Vagin struct ptrace_peeksiginfo_args arg; 69384c751bdSAndrey Vagin struct sigpending *pending; 69484c751bdSAndrey Vagin struct sigqueue *q; 69584c751bdSAndrey Vagin int ret, i; 69684c751bdSAndrey Vagin 69784c751bdSAndrey Vagin ret = copy_from_user(&arg, (void __user *) addr, 69884c751bdSAndrey Vagin sizeof(struct ptrace_peeksiginfo_args)); 69984c751bdSAndrey Vagin if (ret) 70084c751bdSAndrey Vagin return -EFAULT; 70184c751bdSAndrey Vagin 70284c751bdSAndrey Vagin if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) 70384c751bdSAndrey Vagin return -EINVAL; /* unknown flags */ 70484c751bdSAndrey Vagin 70584c751bdSAndrey Vagin if (arg.nr < 0) 70684c751bdSAndrey Vagin return -EINVAL; 70784c751bdSAndrey Vagin 70884c751bdSAndrey Vagin if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) 70984c751bdSAndrey Vagin pending = &child->signal->shared_pending; 71084c751bdSAndrey Vagin else 71184c751bdSAndrey Vagin pending = &child->pending; 71284c751bdSAndrey Vagin 71384c751bdSAndrey Vagin for (i = 0; i < arg.nr; ) { 714ae7795bcSEric W. Biederman kernel_siginfo_t info; 71584c751bdSAndrey Vagin s32 off = arg.off + i; 71684c751bdSAndrey Vagin 71784c751bdSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 71884c751bdSAndrey Vagin list_for_each_entry(q, &pending->list, list) { 71984c751bdSAndrey Vagin if (!off--) { 72084c751bdSAndrey Vagin copy_siginfo(&info, &q->info); 72184c751bdSAndrey Vagin break; 72284c751bdSAndrey Vagin } 72384c751bdSAndrey Vagin } 72484c751bdSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 72584c751bdSAndrey Vagin 72684c751bdSAndrey Vagin if (off >= 0) /* beyond the end of the list */ 72784c751bdSAndrey Vagin break; 72884c751bdSAndrey Vagin 72984c751bdSAndrey Vagin #ifdef CONFIG_COMPAT 7305c465217SAndy Lutomirski if (unlikely(in_compat_syscall())) { 73184c751bdSAndrey Vagin compat_siginfo_t __user *uinfo = compat_ptr(data); 73284c751bdSAndrey Vagin 733cc731525SEric W. Biederman if (copy_siginfo_to_user32(uinfo, &info)) { 734706b23bdSMathieu Desnoyers ret = -EFAULT; 735706b23bdSMathieu Desnoyers break; 736706b23bdSMathieu Desnoyers } 737706b23bdSMathieu Desnoyers 73884c751bdSAndrey Vagin } else 73984c751bdSAndrey Vagin #endif 74084c751bdSAndrey Vagin { 74184c751bdSAndrey Vagin siginfo_t __user *uinfo = (siginfo_t __user *) data; 74284c751bdSAndrey Vagin 743cc731525SEric W. Biederman if (copy_siginfo_to_user(uinfo, &info)) { 74484c751bdSAndrey Vagin ret = -EFAULT; 74584c751bdSAndrey Vagin break; 74684c751bdSAndrey Vagin } 747706b23bdSMathieu Desnoyers } 74884c751bdSAndrey Vagin 74984c751bdSAndrey Vagin data += sizeof(siginfo_t); 75084c751bdSAndrey Vagin i++; 75184c751bdSAndrey Vagin 75284c751bdSAndrey Vagin if (signal_pending(current)) 75384c751bdSAndrey Vagin break; 75484c751bdSAndrey Vagin 75584c751bdSAndrey Vagin cond_resched(); 75684c751bdSAndrey Vagin } 75784c751bdSAndrey Vagin 75884c751bdSAndrey Vagin if (i > 0) 75984c751bdSAndrey Vagin return i; 76084c751bdSAndrey Vagin 76184c751bdSAndrey Vagin return ret; 76284c751bdSAndrey Vagin } 76336df29d7SRoland McGrath 76436df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 76536df29d7SRoland McGrath #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) 76636df29d7SRoland McGrath #else 76736df29d7SRoland McGrath #define is_singlestep(request) 0 76836df29d7SRoland McGrath #endif 76936df29d7SRoland McGrath 7705b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 7715b88abbfSRoland McGrath #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) 7725b88abbfSRoland McGrath #else 7735b88abbfSRoland McGrath #define is_singleblock(request) 0 7745b88abbfSRoland McGrath #endif 7755b88abbfSRoland McGrath 77636df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 77736df29d7SRoland McGrath #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) 77836df29d7SRoland McGrath #else 77936df29d7SRoland McGrath #define is_sysemu_singlestep(request) 0 78036df29d7SRoland McGrath #endif 78136df29d7SRoland McGrath 7824abf9869SNamhyung Kim static int ptrace_resume(struct task_struct *child, long request, 7834abf9869SNamhyung Kim unsigned long data) 78436df29d7SRoland McGrath { 785b72c1869SOleg Nesterov bool need_siglock; 786b72c1869SOleg Nesterov 78736df29d7SRoland McGrath if (!valid_signal(data)) 78836df29d7SRoland McGrath return -EIO; 78936df29d7SRoland McGrath 79036df29d7SRoland McGrath if (request == PTRACE_SYSCALL) 79136df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 79236df29d7SRoland McGrath else 79336df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 79436df29d7SRoland McGrath 79536df29d7SRoland McGrath #ifdef TIF_SYSCALL_EMU 79636df29d7SRoland McGrath if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) 79736df29d7SRoland McGrath set_tsk_thread_flag(child, TIF_SYSCALL_EMU); 79836df29d7SRoland McGrath else 79936df29d7SRoland McGrath clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); 80036df29d7SRoland McGrath #endif 80136df29d7SRoland McGrath 8025b88abbfSRoland McGrath if (is_singleblock(request)) { 8035b88abbfSRoland McGrath if (unlikely(!arch_has_block_step())) 8045b88abbfSRoland McGrath return -EIO; 8055b88abbfSRoland McGrath user_enable_block_step(child); 8065b88abbfSRoland McGrath } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { 80736df29d7SRoland McGrath if (unlikely(!arch_has_single_step())) 80836df29d7SRoland McGrath return -EIO; 80936df29d7SRoland McGrath user_enable_single_step(child); 8103a709703SRoland McGrath } else { 81136df29d7SRoland McGrath user_disable_single_step(child); 8123a709703SRoland McGrath } 81336df29d7SRoland McGrath 814b72c1869SOleg Nesterov /* 815b72c1869SOleg Nesterov * Change ->exit_code and ->state under siglock to avoid the race 816b72c1869SOleg Nesterov * with wait_task_stopped() in between; a non-zero ->exit_code will 817b72c1869SOleg Nesterov * wrongly look like another report from tracee. 818b72c1869SOleg Nesterov * 819b72c1869SOleg Nesterov * Note that we need siglock even if ->exit_code == data and/or this 820b72c1869SOleg Nesterov * status was not reported yet, the new status must not be cleared by 821b72c1869SOleg Nesterov * wait_task_stopped() after resume. 822b72c1869SOleg Nesterov * 823b72c1869SOleg Nesterov * If data == 0 we do not care if wait_task_stopped() reports the old 824b72c1869SOleg Nesterov * status and clears the code too; this can't race with the tracee, it 825b72c1869SOleg Nesterov * takes siglock after resume. 826b72c1869SOleg Nesterov */ 827b72c1869SOleg Nesterov need_siglock = data && !thread_group_empty(current); 828b72c1869SOleg Nesterov if (need_siglock) 829b72c1869SOleg Nesterov spin_lock_irq(&child->sighand->siglock); 83036df29d7SRoland McGrath child->exit_code = data; 8310666fb51SOleg Nesterov wake_up_state(child, __TASK_TRACED); 832b72c1869SOleg Nesterov if (need_siglock) 833b72c1869SOleg Nesterov spin_unlock_irq(&child->sighand->siglock); 83436df29d7SRoland McGrath 83536df29d7SRoland McGrath return 0; 83636df29d7SRoland McGrath } 83736df29d7SRoland McGrath 8382225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 8392225a122SSuresh Siddha 8402225a122SSuresh Siddha static const struct user_regset * 8412225a122SSuresh Siddha find_regset(const struct user_regset_view *view, unsigned int type) 8422225a122SSuresh Siddha { 8432225a122SSuresh Siddha const struct user_regset *regset; 8442225a122SSuresh Siddha int n; 8452225a122SSuresh Siddha 8462225a122SSuresh Siddha for (n = 0; n < view->n; ++n) { 8472225a122SSuresh Siddha regset = view->regsets + n; 8482225a122SSuresh Siddha if (regset->core_note_type == type) 8492225a122SSuresh Siddha return regset; 8502225a122SSuresh Siddha } 8512225a122SSuresh Siddha 8522225a122SSuresh Siddha return NULL; 8532225a122SSuresh Siddha } 8542225a122SSuresh Siddha 8552225a122SSuresh Siddha static int ptrace_regset(struct task_struct *task, int req, unsigned int type, 8562225a122SSuresh Siddha struct iovec *kiov) 8572225a122SSuresh Siddha { 8582225a122SSuresh Siddha const struct user_regset_view *view = task_user_regset_view(task); 8592225a122SSuresh Siddha const struct user_regset *regset = find_regset(view, type); 8602225a122SSuresh Siddha int regset_no; 8612225a122SSuresh Siddha 8622225a122SSuresh Siddha if (!regset || (kiov->iov_len % regset->size) != 0) 863c6a0dd7eSSuresh Siddha return -EINVAL; 8642225a122SSuresh Siddha 8652225a122SSuresh Siddha regset_no = regset - view->regsets; 8662225a122SSuresh Siddha kiov->iov_len = min(kiov->iov_len, 8672225a122SSuresh Siddha (__kernel_size_t) (regset->n * regset->size)); 8682225a122SSuresh Siddha 8692225a122SSuresh Siddha if (req == PTRACE_GETREGSET) 8702225a122SSuresh Siddha return copy_regset_to_user(task, view, regset_no, 0, 8712225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 8722225a122SSuresh Siddha else 8732225a122SSuresh Siddha return copy_regset_from_user(task, view, regset_no, 0, 8742225a122SSuresh Siddha kiov->iov_len, kiov->iov_base); 8752225a122SSuresh Siddha } 8762225a122SSuresh Siddha 877e8440c14SJosh Stone /* 878e8440c14SJosh Stone * This is declared in linux/regset.h and defined in machine-dependent 879e8440c14SJosh Stone * code. We put the export here, near the primary machine-neutral use, 880e8440c14SJosh Stone * to ensure no machine forgets it. 881e8440c14SJosh Stone */ 882e8440c14SJosh Stone EXPORT_SYMBOL_GPL(task_user_regset_view); 8832225a122SSuresh Siddha #endif 8842225a122SSuresh Siddha 8851da177e4SLinus Torvalds int ptrace_request(struct task_struct *child, long request, 8864abf9869SNamhyung Kim unsigned long addr, unsigned long data) 8871da177e4SLinus Torvalds { 888fca26f26STejun Heo bool seized = child->ptrace & PT_SEIZED; 8891da177e4SLinus Torvalds int ret = -EIO; 890ae7795bcSEric W. Biederman kernel_siginfo_t siginfo, *si; 8919fed81dcSNamhyung Kim void __user *datavp = (void __user *) data; 8929fed81dcSNamhyung Kim unsigned long __user *datalp = datavp; 893fca26f26STejun Heo unsigned long flags; 8941da177e4SLinus Torvalds 8951da177e4SLinus Torvalds switch (request) { 89616c3e389SRoland McGrath case PTRACE_PEEKTEXT: 89716c3e389SRoland McGrath case PTRACE_PEEKDATA: 89816c3e389SRoland McGrath return generic_ptrace_peekdata(child, addr, data); 89916c3e389SRoland McGrath case PTRACE_POKETEXT: 90016c3e389SRoland McGrath case PTRACE_POKEDATA: 90116c3e389SRoland McGrath return generic_ptrace_pokedata(child, addr, data); 90216c3e389SRoland McGrath 9031da177e4SLinus Torvalds #ifdef PTRACE_OLDSETOPTIONS 9041da177e4SLinus Torvalds case PTRACE_OLDSETOPTIONS: 9051da177e4SLinus Torvalds #endif 9061da177e4SLinus Torvalds case PTRACE_SETOPTIONS: 9071da177e4SLinus Torvalds ret = ptrace_setoptions(child, data); 9081da177e4SLinus Torvalds break; 9091da177e4SLinus Torvalds case PTRACE_GETEVENTMSG: 9109fed81dcSNamhyung Kim ret = put_user(child->ptrace_message, datalp); 9111da177e4SLinus Torvalds break; 912e16b2781SRoland McGrath 91384c751bdSAndrey Vagin case PTRACE_PEEKSIGINFO: 91484c751bdSAndrey Vagin ret = ptrace_peek_siginfo(child, addr, data); 91584c751bdSAndrey Vagin break; 91684c751bdSAndrey Vagin 9171da177e4SLinus Torvalds case PTRACE_GETSIGINFO: 918e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 919e16b2781SRoland McGrath if (!ret) 9209fed81dcSNamhyung Kim ret = copy_siginfo_to_user(datavp, &siginfo); 9211da177e4SLinus Torvalds break; 922e16b2781SRoland McGrath 9231da177e4SLinus Torvalds case PTRACE_SETSIGINFO: 9244cd2e0e7SEric W. Biederman ret = copy_siginfo_from_user(&siginfo, datavp); 9254cd2e0e7SEric W. Biederman if (!ret) 926e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 9271da177e4SLinus Torvalds break; 928e16b2781SRoland McGrath 929fcfc2aa0SAndrei Vagin case PTRACE_GETSIGMASK: { 930fcfc2aa0SAndrei Vagin sigset_t *mask; 931fcfc2aa0SAndrei Vagin 93229000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 93329000caeSAndrey Vagin ret = -EINVAL; 93429000caeSAndrey Vagin break; 93529000caeSAndrey Vagin } 93629000caeSAndrey Vagin 937fcfc2aa0SAndrei Vagin if (test_tsk_restore_sigmask(child)) 938fcfc2aa0SAndrei Vagin mask = &child->saved_sigmask; 939fcfc2aa0SAndrei Vagin else 940fcfc2aa0SAndrei Vagin mask = &child->blocked; 941fcfc2aa0SAndrei Vagin 942fcfc2aa0SAndrei Vagin if (copy_to_user(datavp, mask, sizeof(sigset_t))) 94329000caeSAndrey Vagin ret = -EFAULT; 94429000caeSAndrey Vagin else 94529000caeSAndrey Vagin ret = 0; 94629000caeSAndrey Vagin 94729000caeSAndrey Vagin break; 948fcfc2aa0SAndrei Vagin } 94929000caeSAndrey Vagin 95029000caeSAndrey Vagin case PTRACE_SETSIGMASK: { 95129000caeSAndrey Vagin sigset_t new_set; 95229000caeSAndrey Vagin 95329000caeSAndrey Vagin if (addr != sizeof(sigset_t)) { 95429000caeSAndrey Vagin ret = -EINVAL; 95529000caeSAndrey Vagin break; 95629000caeSAndrey Vagin } 95729000caeSAndrey Vagin 95829000caeSAndrey Vagin if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { 95929000caeSAndrey Vagin ret = -EFAULT; 96029000caeSAndrey Vagin break; 96129000caeSAndrey Vagin } 96229000caeSAndrey Vagin 96329000caeSAndrey Vagin sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); 96429000caeSAndrey Vagin 96529000caeSAndrey Vagin /* 96629000caeSAndrey Vagin * Every thread does recalc_sigpending() after resume, so 96729000caeSAndrey Vagin * retarget_shared_pending() and recalc_sigpending() are not 96829000caeSAndrey Vagin * called here. 96929000caeSAndrey Vagin */ 97029000caeSAndrey Vagin spin_lock_irq(&child->sighand->siglock); 97129000caeSAndrey Vagin child->blocked = new_set; 97229000caeSAndrey Vagin spin_unlock_irq(&child->sighand->siglock); 97329000caeSAndrey Vagin 974fcfc2aa0SAndrei Vagin clear_tsk_restore_sigmask(child); 975fcfc2aa0SAndrei Vagin 97629000caeSAndrey Vagin ret = 0; 97729000caeSAndrey Vagin break; 97829000caeSAndrey Vagin } 97929000caeSAndrey Vagin 980fca26f26STejun Heo case PTRACE_INTERRUPT: 981fca26f26STejun Heo /* 982fca26f26STejun Heo * Stop tracee without any side-effect on signal or job 983fca26f26STejun Heo * control. At least one trap is guaranteed to happen 984fca26f26STejun Heo * after this request. If @child is already trapped, the 985fca26f26STejun Heo * current trap is not disturbed and another trap will 986fca26f26STejun Heo * happen after the current trap is ended with PTRACE_CONT. 987fca26f26STejun Heo * 988fca26f26STejun Heo * The actual trap might not be PTRACE_EVENT_STOP trap but 989fca26f26STejun Heo * the pending condition is cleared regardless. 990fca26f26STejun Heo */ 991fca26f26STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 992fca26f26STejun Heo break; 993fca26f26STejun Heo 994544b2c91STejun Heo /* 995544b2c91STejun Heo * INTERRUPT doesn't disturb existing trap sans one 996544b2c91STejun Heo * exception. If ptracer issued LISTEN for the current 997544b2c91STejun Heo * STOP, this INTERRUPT should clear LISTEN and re-trap 998544b2c91STejun Heo * tracee into STOP. 999544b2c91STejun Heo */ 1000fca26f26STejun Heo if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) 1001910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); 1002544b2c91STejun Heo 1003544b2c91STejun Heo unlock_task_sighand(child, &flags); 1004544b2c91STejun Heo ret = 0; 1005544b2c91STejun Heo break; 1006544b2c91STejun Heo 1007544b2c91STejun Heo case PTRACE_LISTEN: 1008544b2c91STejun Heo /* 1009544b2c91STejun Heo * Listen for events. Tracee must be in STOP. It's not 1010544b2c91STejun Heo * resumed per-se but is not considered to be in TRACED by 1011544b2c91STejun Heo * wait(2) or ptrace(2). If an async event (e.g. group 1012544b2c91STejun Heo * stop state change) happens, tracee will enter STOP trap 1013544b2c91STejun Heo * again. Alternatively, ptracer can issue INTERRUPT to 1014544b2c91STejun Heo * finish listening and re-trap tracee into STOP. 1015544b2c91STejun Heo */ 1016544b2c91STejun Heo if (unlikely(!seized || !lock_task_sighand(child, &flags))) 1017544b2c91STejun Heo break; 1018544b2c91STejun Heo 1019544b2c91STejun Heo si = child->last_siginfo; 1020f9d81f61SOleg Nesterov if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { 1021544b2c91STejun Heo child->jobctl |= JOBCTL_LISTENING; 1022544b2c91STejun Heo /* 1023f9d81f61SOleg Nesterov * If NOTIFY is set, it means event happened between 1024f9d81f61SOleg Nesterov * start of this trap and now. Trigger re-trap. 1025544b2c91STejun Heo */ 1026544b2c91STejun Heo if (child->jobctl & JOBCTL_TRAP_NOTIFY) 1027910ffdb1SOleg Nesterov ptrace_signal_wake_up(child, true); 1028fca26f26STejun Heo ret = 0; 1029f9d81f61SOleg Nesterov } 1030f9d81f61SOleg Nesterov unlock_task_sighand(child, &flags); 1031fca26f26STejun Heo break; 1032fca26f26STejun Heo 10331bcf5482SAlexey Dobriyan case PTRACE_DETACH: /* detach a process that was attached. */ 10341bcf5482SAlexey Dobriyan ret = ptrace_detach(child, data); 10351bcf5482SAlexey Dobriyan break; 103636df29d7SRoland McGrath 10379c1a1259SMike Frysinger #ifdef CONFIG_BINFMT_ELF_FDPIC 10389c1a1259SMike Frysinger case PTRACE_GETFDPIC: { 1039e0129ef9SOleg Nesterov struct mm_struct *mm = get_task_mm(child); 10409c1a1259SMike Frysinger unsigned long tmp = 0; 10419c1a1259SMike Frysinger 1042e0129ef9SOleg Nesterov ret = -ESRCH; 1043e0129ef9SOleg Nesterov if (!mm) 1044e0129ef9SOleg Nesterov break; 1045e0129ef9SOleg Nesterov 10469c1a1259SMike Frysinger switch (addr) { 10479c1a1259SMike Frysinger case PTRACE_GETFDPIC_EXEC: 1048e0129ef9SOleg Nesterov tmp = mm->context.exec_fdpic_loadmap; 10499c1a1259SMike Frysinger break; 10509c1a1259SMike Frysinger case PTRACE_GETFDPIC_INTERP: 1051e0129ef9SOleg Nesterov tmp = mm->context.interp_fdpic_loadmap; 10529c1a1259SMike Frysinger break; 10539c1a1259SMike Frysinger default: 10549c1a1259SMike Frysinger break; 10559c1a1259SMike Frysinger } 1056e0129ef9SOleg Nesterov mmput(mm); 10579c1a1259SMike Frysinger 10589fed81dcSNamhyung Kim ret = put_user(tmp, datalp); 10599c1a1259SMike Frysinger break; 10609c1a1259SMike Frysinger } 10619c1a1259SMike Frysinger #endif 10629c1a1259SMike Frysinger 106336df29d7SRoland McGrath #ifdef PTRACE_SINGLESTEP 106436df29d7SRoland McGrath case PTRACE_SINGLESTEP: 106536df29d7SRoland McGrath #endif 10665b88abbfSRoland McGrath #ifdef PTRACE_SINGLEBLOCK 10675b88abbfSRoland McGrath case PTRACE_SINGLEBLOCK: 10685b88abbfSRoland McGrath #endif 106936df29d7SRoland McGrath #ifdef PTRACE_SYSEMU 107036df29d7SRoland McGrath case PTRACE_SYSEMU: 107136df29d7SRoland McGrath case PTRACE_SYSEMU_SINGLESTEP: 107236df29d7SRoland McGrath #endif 107336df29d7SRoland McGrath case PTRACE_SYSCALL: 107436df29d7SRoland McGrath case PTRACE_CONT: 107536df29d7SRoland McGrath return ptrace_resume(child, request, data); 107636df29d7SRoland McGrath 107736df29d7SRoland McGrath case PTRACE_KILL: 107836df29d7SRoland McGrath if (child->exit_state) /* already dead */ 107936df29d7SRoland McGrath return 0; 108036df29d7SRoland McGrath return ptrace_resume(child, request, SIGKILL); 108136df29d7SRoland McGrath 10822225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 10832225a122SSuresh Siddha case PTRACE_GETREGSET: 108429000caeSAndrey Vagin case PTRACE_SETREGSET: { 10852225a122SSuresh Siddha struct iovec kiov; 10869fed81dcSNamhyung Kim struct iovec __user *uiov = datavp; 10872225a122SSuresh Siddha 108896d4f267SLinus Torvalds if (!access_ok(uiov, sizeof(*uiov))) 10892225a122SSuresh Siddha return -EFAULT; 10902225a122SSuresh Siddha 10912225a122SSuresh Siddha if (__get_user(kiov.iov_base, &uiov->iov_base) || 10922225a122SSuresh Siddha __get_user(kiov.iov_len, &uiov->iov_len)) 10932225a122SSuresh Siddha return -EFAULT; 10942225a122SSuresh Siddha 10952225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 10962225a122SSuresh Siddha if (!ret) 10972225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 10982225a122SSuresh Siddha break; 10992225a122SSuresh Siddha } 11002225a122SSuresh Siddha #endif 1101f8e529edSTycho Andersen 1102f8e529edSTycho Andersen case PTRACE_SECCOMP_GET_FILTER: 1103f8e529edSTycho Andersen ret = seccomp_get_filter(child, addr, datavp); 1104f8e529edSTycho Andersen break; 1105f8e529edSTycho Andersen 110626500475STycho Andersen case PTRACE_SECCOMP_GET_METADATA: 110726500475STycho Andersen ret = seccomp_get_metadata(child, addr, datavp); 110826500475STycho Andersen break; 110926500475STycho Andersen 11101da177e4SLinus Torvalds default: 11111da177e4SLinus Torvalds break; 11121da177e4SLinus Torvalds } 11131da177e4SLinus Torvalds 11141da177e4SLinus Torvalds return ret; 11151da177e4SLinus Torvalds } 1116481bed45SChristoph Hellwig 11170ac15559SChristoph Hellwig #ifndef arch_ptrace_attach 11180ac15559SChristoph Hellwig #define arch_ptrace_attach(child) do { } while (0) 11190ac15559SChristoph Hellwig #endif 11200ac15559SChristoph Hellwig 11214abf9869SNamhyung Kim SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, 11224abf9869SNamhyung Kim unsigned long, data) 1123481bed45SChristoph Hellwig { 1124481bed45SChristoph Hellwig struct task_struct *child; 1125481bed45SChristoph Hellwig long ret; 1126481bed45SChristoph Hellwig 11276b9c7ed8SChristoph Hellwig if (request == PTRACE_TRACEME) { 11286b9c7ed8SChristoph Hellwig ret = ptrace_traceme(); 11296ea6dd93SHaavard Skinnemoen if (!ret) 11306ea6dd93SHaavard Skinnemoen arch_ptrace_attach(current); 1131481bed45SChristoph Hellwig goto out; 11326b9c7ed8SChristoph Hellwig } 11336b9c7ed8SChristoph Hellwig 11342ee08260SMike Rapoport child = find_get_task_by_vpid(pid); 11352ee08260SMike Rapoport if (!child) { 11362ee08260SMike Rapoport ret = -ESRCH; 11376b9c7ed8SChristoph Hellwig goto out; 11386b9c7ed8SChristoph Hellwig } 1139481bed45SChristoph Hellwig 11403544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1141aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 11420ac15559SChristoph Hellwig /* 11430ac15559SChristoph Hellwig * Some architectures need to do book-keeping after 11440ac15559SChristoph Hellwig * a ptrace attach. 11450ac15559SChristoph Hellwig */ 11460ac15559SChristoph Hellwig if (!ret) 11470ac15559SChristoph Hellwig arch_ptrace_attach(child); 1148005f18dfSChristoph Hellwig goto out_put_task_struct; 1149481bed45SChristoph Hellwig } 1150481bed45SChristoph Hellwig 1151fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1152fca26f26STejun Heo request == PTRACE_INTERRUPT); 1153481bed45SChristoph Hellwig if (ret < 0) 1154481bed45SChristoph Hellwig goto out_put_task_struct; 1155481bed45SChristoph Hellwig 1156481bed45SChristoph Hellwig ret = arch_ptrace(child, request, addr, data); 11579899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 11589899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 1159481bed45SChristoph Hellwig 1160481bed45SChristoph Hellwig out_put_task_struct: 1161481bed45SChristoph Hellwig put_task_struct(child); 1162481bed45SChristoph Hellwig out: 1163481bed45SChristoph Hellwig return ret; 1164481bed45SChristoph Hellwig } 116576647323SAlexey Dobriyan 11664abf9869SNamhyung Kim int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 11674abf9869SNamhyung Kim unsigned long data) 116876647323SAlexey Dobriyan { 116976647323SAlexey Dobriyan unsigned long tmp; 117076647323SAlexey Dobriyan int copied; 117176647323SAlexey Dobriyan 117284d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); 117376647323SAlexey Dobriyan if (copied != sizeof(tmp)) 117476647323SAlexey Dobriyan return -EIO; 117576647323SAlexey Dobriyan return put_user(tmp, (unsigned long __user *)data); 117676647323SAlexey Dobriyan } 1177f284ce72SAlexey Dobriyan 11784abf9869SNamhyung Kim int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 11794abf9869SNamhyung Kim unsigned long data) 1180f284ce72SAlexey Dobriyan { 1181f284ce72SAlexey Dobriyan int copied; 1182f284ce72SAlexey Dobriyan 118384d77d3fSEric W. Biederman copied = ptrace_access_vm(tsk, addr, &data, sizeof(data), 1184f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1185f284ce72SAlexey Dobriyan return (copied == sizeof(data)) ? 0 : -EIO; 1186f284ce72SAlexey Dobriyan } 1187032d82d9SRoland McGrath 118896b8936aSChristoph Hellwig #if defined CONFIG_COMPAT 1189032d82d9SRoland McGrath 1190032d82d9SRoland McGrath int compat_ptrace_request(struct task_struct *child, compat_long_t request, 1191032d82d9SRoland McGrath compat_ulong_t addr, compat_ulong_t data) 1192032d82d9SRoland McGrath { 1193032d82d9SRoland McGrath compat_ulong_t __user *datap = compat_ptr(data); 1194032d82d9SRoland McGrath compat_ulong_t word; 1195ae7795bcSEric W. Biederman kernel_siginfo_t siginfo; 1196032d82d9SRoland McGrath int ret; 1197032d82d9SRoland McGrath 1198032d82d9SRoland McGrath switch (request) { 1199032d82d9SRoland McGrath case PTRACE_PEEKTEXT: 1200032d82d9SRoland McGrath case PTRACE_PEEKDATA: 120184d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &word, sizeof(word), 1202f307ab6dSLorenzo Stoakes FOLL_FORCE); 1203032d82d9SRoland McGrath if (ret != sizeof(word)) 1204032d82d9SRoland McGrath ret = -EIO; 1205032d82d9SRoland McGrath else 1206032d82d9SRoland McGrath ret = put_user(word, datap); 1207032d82d9SRoland McGrath break; 1208032d82d9SRoland McGrath 1209032d82d9SRoland McGrath case PTRACE_POKETEXT: 1210032d82d9SRoland McGrath case PTRACE_POKEDATA: 121184d77d3fSEric W. Biederman ret = ptrace_access_vm(child, addr, &data, sizeof(data), 1212f307ab6dSLorenzo Stoakes FOLL_FORCE | FOLL_WRITE); 1213032d82d9SRoland McGrath ret = (ret != sizeof(data) ? -EIO : 0); 1214032d82d9SRoland McGrath break; 1215032d82d9SRoland McGrath 1216032d82d9SRoland McGrath case PTRACE_GETEVENTMSG: 1217032d82d9SRoland McGrath ret = put_user((compat_ulong_t) child->ptrace_message, datap); 1218032d82d9SRoland McGrath break; 1219032d82d9SRoland McGrath 1220e16b2781SRoland McGrath case PTRACE_GETSIGINFO: 1221e16b2781SRoland McGrath ret = ptrace_getsiginfo(child, &siginfo); 1222e16b2781SRoland McGrath if (!ret) 1223e16b2781SRoland McGrath ret = copy_siginfo_to_user32( 1224e16b2781SRoland McGrath (struct compat_siginfo __user *) datap, 1225e16b2781SRoland McGrath &siginfo); 1226e16b2781SRoland McGrath break; 1227e16b2781SRoland McGrath 1228e16b2781SRoland McGrath case PTRACE_SETSIGINFO: 12294cd2e0e7SEric W. Biederman ret = copy_siginfo_from_user32( 12304cd2e0e7SEric W. Biederman &siginfo, (struct compat_siginfo __user *) datap); 12314cd2e0e7SEric W. Biederman if (!ret) 1232e16b2781SRoland McGrath ret = ptrace_setsiginfo(child, &siginfo); 1233e16b2781SRoland McGrath break; 12342225a122SSuresh Siddha #ifdef CONFIG_HAVE_ARCH_TRACEHOOK 12352225a122SSuresh Siddha case PTRACE_GETREGSET: 12362225a122SSuresh Siddha case PTRACE_SETREGSET: 12372225a122SSuresh Siddha { 12382225a122SSuresh Siddha struct iovec kiov; 12392225a122SSuresh Siddha struct compat_iovec __user *uiov = 12402225a122SSuresh Siddha (struct compat_iovec __user *) datap; 12412225a122SSuresh Siddha compat_uptr_t ptr; 12422225a122SSuresh Siddha compat_size_t len; 12432225a122SSuresh Siddha 124496d4f267SLinus Torvalds if (!access_ok(uiov, sizeof(*uiov))) 12452225a122SSuresh Siddha return -EFAULT; 12462225a122SSuresh Siddha 12472225a122SSuresh Siddha if (__get_user(ptr, &uiov->iov_base) || 12482225a122SSuresh Siddha __get_user(len, &uiov->iov_len)) 12492225a122SSuresh Siddha return -EFAULT; 12502225a122SSuresh Siddha 12512225a122SSuresh Siddha kiov.iov_base = compat_ptr(ptr); 12522225a122SSuresh Siddha kiov.iov_len = len; 12532225a122SSuresh Siddha 12542225a122SSuresh Siddha ret = ptrace_regset(child, request, addr, &kiov); 12552225a122SSuresh Siddha if (!ret) 12562225a122SSuresh Siddha ret = __put_user(kiov.iov_len, &uiov->iov_len); 12572225a122SSuresh Siddha break; 12582225a122SSuresh Siddha } 12592225a122SSuresh Siddha #endif 1260e16b2781SRoland McGrath 1261032d82d9SRoland McGrath default: 1262032d82d9SRoland McGrath ret = ptrace_request(child, request, addr, data); 1263032d82d9SRoland McGrath } 1264032d82d9SRoland McGrath 1265032d82d9SRoland McGrath return ret; 1266032d82d9SRoland McGrath } 1267c269f196SRoland McGrath 126862a6fa97SHeiko Carstens COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, 126962a6fa97SHeiko Carstens compat_long_t, addr, compat_long_t, data) 1270c269f196SRoland McGrath { 1271c269f196SRoland McGrath struct task_struct *child; 1272c269f196SRoland McGrath long ret; 1273c269f196SRoland McGrath 1274c269f196SRoland McGrath if (request == PTRACE_TRACEME) { 1275c269f196SRoland McGrath ret = ptrace_traceme(); 1276c269f196SRoland McGrath goto out; 1277c269f196SRoland McGrath } 1278c269f196SRoland McGrath 12792ee08260SMike Rapoport child = find_get_task_by_vpid(pid); 12802ee08260SMike Rapoport if (!child) { 12812ee08260SMike Rapoport ret = -ESRCH; 1282c269f196SRoland McGrath goto out; 1283c269f196SRoland McGrath } 1284c269f196SRoland McGrath 12853544d72aSTejun Heo if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { 1286aa9147c9SDenys Vlasenko ret = ptrace_attach(child, request, addr, data); 1287c269f196SRoland McGrath /* 1288c269f196SRoland McGrath * Some architectures need to do book-keeping after 1289c269f196SRoland McGrath * a ptrace attach. 1290c269f196SRoland McGrath */ 1291c269f196SRoland McGrath if (!ret) 1292c269f196SRoland McGrath arch_ptrace_attach(child); 1293c269f196SRoland McGrath goto out_put_task_struct; 1294c269f196SRoland McGrath } 1295c269f196SRoland McGrath 1296fca26f26STejun Heo ret = ptrace_check_attach(child, request == PTRACE_KILL || 1297fca26f26STejun Heo request == PTRACE_INTERRUPT); 12989899d11fSOleg Nesterov if (!ret) { 1299c269f196SRoland McGrath ret = compat_arch_ptrace(child, request, addr, data); 13009899d11fSOleg Nesterov if (ret || request != PTRACE_DETACH) 13019899d11fSOleg Nesterov ptrace_unfreeze_traced(child); 13029899d11fSOleg Nesterov } 1303c269f196SRoland McGrath 1304c269f196SRoland McGrath out_put_task_struct: 1305c269f196SRoland McGrath put_task_struct(child); 1306c269f196SRoland McGrath out: 1307c269f196SRoland McGrath return ret; 1308c269f196SRoland McGrath } 130996b8936aSChristoph Hellwig #endif /* CONFIG_COMPAT */ 1310