| 1 | |
| 2 | |
| 3 | * linux/kernel/ptrace.c
|
| 4 | *
|
| 5 | * (C) Copyright 1999 Linus Torvalds
|
| 6 | *
|
| 7 | * Common interfaces for "ptrace()" which we do not want
|
| 8 | * to continually duplicate across every architecture.
|
| 9 |
|
| 10 |
|
| 11 | #include <linux/capability.h>
|
| 12 | #include <linux/export.h>
|
| 13 | #include <linux/sched.h>
|
| 14 | #include <linux/sched/mm.h>
|
| 15 | #include <linux/sched/coredump.h>
|
| 16 | #include <linux/sched/task.h>
|
| 17 | #include <linux/errno.h>
|
| 18 | #include <linux/mm.h>
|
| 19 | #include <linux/highmem.h>
|
| 20 | #include <linux/pagemap.h>
|
| 21 | #include <linux/ptrace.h>
|
| 22 | #include <linux/security.h>
|
| 23 | #include <linux/signal.h>
|
| 24 | #include <linux/uio.h>
|
| 25 | #include <linux/audit.h>
|
| 26 | #include <linux/pid_namespace.h>
|
| 27 | #include <linux/syscalls.h>
|
| 28 | #include <linux/uaccess.h>
|
| 29 | #include <linux/regset.h>
|
| 30 | #include <linux/hw_breakpoint.h>
|
| 31 | #include <linux/cn_proc.h>
|
| 32 | #include <linux/compat.h>
|
| 33 | #include <linux/sched/signal.h>
|
| 34 | #include <linux/minmax.h>
|
| 35 | #include <linux/syscall_user_dispatch.h>
|
| 36 |
|
| 37 | #include <asm/syscall.h>
|
| 38 |
|
| 39 | |
| 40 | * Access another process' address space via ptrace.
|
| 41 | * Source/target buffer must be kernel space,
|
| 42 | * Do not walk the page table directly, use get_user_pages
|
| 43 |
|
| 44 | int ptrace_access_vm(struct task_struct *tsk, unsigned long addr,
|
| 45 | void *buf, int len, unsigned int gup_flags)
|
| 46 | {
|
| 47 | struct mm_struct *mm;
|
| 48 | int ret;
|
| 49 |
|
| 50 | mm = get_task_mm(tsk);
|
| 51 | if (!mm)
|
| 52 | return 0;
|
| 53 |
|
| 54 | if (!tsk->ptrace ||
|
| 55 | (current != tsk->parent) ||
|
| 56 | ((get_dumpable(mm) != SUID_DUMP_USER) &&
|
| 57 | !ptracer_capable(tsk, mm->user_ns))) {
|
| 58 | mmput(mm);
|
| 59 | return 0;
|
| 60 | }
|
| 61 |
|
| 62 | ret = __access_remote_vm(mm, addr, buf, len, gup_flags);
|
| 63 | mmput(mm);
|
| 64 |
|
| 65 | return ret;
|
| 66 | }
|
| 67 |
|
| 68 |
|
| 69 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent,
|
| 70 | const struct cred *ptracer_cred)
|
| 71 | {
|
| 72 | BUG_ON(!list_empty(&child->ptrace_entry));
|
| 73 | list_add(&child->ptrace_entry, &new_parent->ptraced);
|
| 74 | child->parent = new_parent;
|
| 75 | child->ptracer_cred = get_cred(ptracer_cred);
|
| 76 | }
|
| 77 |
|
| 78 | |
| 79 | * ptrace a task: make the debugger its new parent and
|
| 80 | * move it to the ptrace list.
|
| 81 | *
|
| 82 | * Must be called with the tasklist lock write-held.
|
| 83 |
|
| 84 | static void ptrace_link(struct task_struct *child, struct task_struct *new_parent)
|
| 85 | {
|
| 86 | __ptrace_link(child, new_parent, current_cred());
|
| 87 | }
|
| 88 |
|
| 89 | |
| 90 | * __ptrace_unlink - unlink ptracee and restore its execution state
|
| 91 | * @child: ptracee to be unlinked
|
| 92 | *
|
| 93 | * Remove @child from the ptrace list, move it back to the original parent,
|
| 94 | * and restore the execution state so that it conforms to the group stop
|
| 95 | * state.
|
| 96 | *
|
| 97 | * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
|
| 98 | * exiting. For PTRACE_DETACH, unless the ptracee has been killed between
|
| 99 | * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
|
| 100 | * If the ptracer is exiting, the ptracee can be in any state.
|
| 101 | *
|
| 102 | * After detach, the ptracee should be in a state which conforms to the
|
| 103 | * group stop. If the group is stopped or in the process of stopping, the
|
| 104 | * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
|
| 105 | * up from TASK_TRACED.
|
| 106 | *
|
| 107 | * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
|
| 108 | * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
|
| 109 | * to but in the opposite direction of what happens while attaching to a
|
| 110 | * stopped task. However, in this direction, the intermediate RUNNING
|
| 111 | * state is not hidden even from the current ptracer and if it immediately
|
| 112 | * re-attaches and performs a WNOHANG wait(2), it may fail.
|
| 113 | *
|
| 114 | * CONTEXT:
|
| 115 | * write_lock_irq(tasklist_lock)
|
| 116 |
|
| 117 | void __ptrace_unlink(struct task_struct *child)
|
| 118 | {
|
| 119 | const struct cred *old_cred;
|
| 120 | BUG_ON(!child->ptrace);
|
| 121 |
|
| 122 | clear_task_syscall_work(child, SYSCALL_TRACE);
|
| 123 | #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU)
|
| 124 | clear_task_syscall_work(child, SYSCALL_EMU);
|
| 125 | #endif
|
| 126 |
|
| 127 | child->parent = child->real_parent;
|
| 128 | list_del_init(&child->ptrace_entry);
|
| 129 | old_cred = child->ptracer_cred;
|
| 130 | child->ptracer_cred = NULL;
|
| 131 | put_cred(old_cred);
|
| 132 |
|
| 133 | spin_lock(&child->sighand->siglock);
|
| 134 | child->ptrace = 0;
|
| 135 | |
| 136 | * Clear all pending traps and TRAPPING. TRAPPING should be
|
| 137 | * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
|
| 138 |
|
| 139 | task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
|
| 140 | task_clear_jobctl_trapping(child);
|
| 141 |
|
| 142 | |
| 143 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
|
| 144 | * @child isn't dead.
|
| 145 |
|
| 146 | if (!(child->flags & PF_EXITING) &&
|
| 147 | (child->signal->flags & SIGNAL_STOP_STOPPED ||
|
| 148 | child->signal->group_stop_count)) {
|
| 149 | child->jobctl |= JOBCTL_STOP_PENDING;
|
| 150 |
|
| 151 | |
| 152 | * This is only possible if this thread was cloned by the
|
| 153 | * traced task running in the stopped group, set the signal
|
| 154 | * for the future reports.
|
| 155 | * FIXME: we should change ptrace_init_task() to handle this
|
| 156 | * case.
|
| 157 |
|
| 158 | if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
|
| 159 | child->jobctl |= SIGSTOP;
|
| 160 | }
|
| 161 |
|
| 162 | |
| 163 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
|
| 164 | * @child in the butt. Note that @resume should be used iff @child
|
| 165 | * is in TASK_TRACED; otherwise, we might unduly disrupt
|
| 166 | * TASK_KILLABLE sleeps.
|
| 167 |
|
| 168 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
|
| 169 | ptrace_signal_wake_up(child, true);
|
| 170 |
|
| 171 | spin_unlock(&child->sighand->siglock);
|
| 172 | }
|
| 173 |
|
| 174 | static bool looks_like_a_spurious_pid(struct task_struct *task)
|
| 175 | {
|
| 176 | if (task->exit_code != ((PTRACE_EVENT_EXEC << 8) | SIGTRAP))
|
| 177 | return false;
|
| 178 |
|
| 179 | if (task_pid_vnr(task) == task->ptrace_message)
|
| 180 | return false;
|
| 181 | |
| 182 | * The tracee changed its pid but the PTRACE_EVENT_EXEC event
|
| 183 | * was not wait()'ed, most probably debugger targets the old
|
| 184 | * leader which was destroyed in de_thread().
|
| 185 |
|
| 186 | return true;
|
| 187 | }
|
| 188 |
|
| 189 | |
| 190 | * Ensure that nothing can wake it up, even SIGKILL
|
| 191 | *
|
| 192 | * A task is switched to this state while a ptrace operation is in progress;
|
| 193 | * such that the ptrace operation is uninterruptible.
|
| 194 |
|
| 195 | static bool ptrace_freeze_traced(struct task_struct *task)
|
| 196 | {
|
| 197 | bool ret = false;
|
| 198 |
|
| 199 |
|
| 200 | if (task->jobctl & JOBCTL_LISTENING)
|
| 201 | return ret;
|
| 202 |
|
| 203 | spin_lock_irq(&task->sighand->siglock);
|
| 204 | if (task_is_traced(task) && !looks_like_a_spurious_pid(task) &&
|
| 205 | !__fatal_signal_pending(task)) {
|
| 206 | task->jobctl |= JOBCTL_PTRACE_FROZEN;
|
| 207 | ret = true;
|
| 208 | }
|
| 209 | spin_unlock_irq(&task->sighand->siglock);
|
| 210 |
|
| 211 | return ret;
|
| 212 | }
|
| 213 |
|
| 214 | static void ptrace_unfreeze_traced(struct task_struct *task)
|
| 215 | {
|
| 216 | unsigned long flags;
|
| 217 |
|
| 218 | |
| 219 | * The child may be awake and may have cleared
|
| 220 | * JOBCTL_PTRACE_FROZEN (see ptrace_resume). The child will
|
| 221 | * not set JOBCTL_PTRACE_FROZEN or enter __TASK_TRACED anew.
|
| 222 |
|
| 223 | if (lock_task_sighand(task, &flags)) {
|
| 224 | task->jobctl &= ~JOBCTL_PTRACE_FROZEN;
|
| 225 | if (__fatal_signal_pending(task)) {
|
| 226 | task->jobctl &= ~JOBCTL_TRACED;
|
| 227 | wake_up_state(task, __TASK_TRACED);
|
| 228 | }
|
| 229 | unlock_task_sighand(task, &flags);
|
| 230 | }
|
| 231 | }
|
| 232 |
|
| 233 | |
| 234 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation
|
| 235 | * @child: ptracee to check for
|
| 236 | * @ignore_state: don't check whether @child is currently %TASK_TRACED
|
| 237 | *
|
| 238 | * Check whether @child is being ptraced by %current and ready for further
|
| 239 | * ptrace operations. If @ignore_state is %false, @child also should be in
|
| 240 | * %TASK_TRACED state and on return the child is guaranteed to be traced
|
| 241 | * and not executing. If @ignore_state is %true, @child can be in any
|
| 242 | * state.
|
| 243 | *
|
| 244 | * CONTEXT:
|
| 245 | * Grabs and releases tasklist_lock and @child->sighand->siglock.
|
| 246 | *
|
| 247 | * RETURNS:
|
| 248 | * 0 on success, -ESRCH if %child is not ready.
|
| 249 |
|
| 250 | static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
|
| 251 | {
|
| 252 | int ret = -ESRCH;
|
| 253 |
|
| 254 | |
| 255 | * We take the read lock around doing both checks to close a
|
| 256 | * possible race where someone else was tracing our child and
|
| 257 | * detached between these two checks. After this locked check,
|
| 258 | * we are sure that this is our traced child and that can only
|
| 259 | * be changed by us so it's not changing right after this.
|
| 260 |
|
| 261 | read_lock(&tasklist_lock);
|
| 262 | if (child->ptrace && child->parent == current) {
|
| 263 | |
| 264 | * child->sighand can't be NULL, release_task()
|
| 265 | * does ptrace_unlink() before __exit_signal().
|
| 266 |
|
| 267 | if (ignore_state || ptrace_freeze_traced(child))
|
| 268 | ret = 0;
|
| 269 | }
|
| 270 | read_unlock(&tasklist_lock);
|
| 271 |
|
| 272 | if (!ret && !ignore_state &&
|
| 273 | WARN_ON_ONCE(!wait_task_inactive(child, __TASK_TRACED|TASK_FROZEN)))
|
| 274 | ret = -ESRCH;
|
| 275 |
|
| 276 | return ret;
|
| 277 | }
|
| 278 |
|
| 279 | static bool ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
|
| 280 | {
|
| 281 | if (mode & PTRACE_MODE_NOAUDIT)
|
| 282 | return ns_capable_noaudit(ns, CAP_SYS_PTRACE);
|
| 283 | return ns_capable(ns, CAP_SYS_PTRACE);
|
| 284 | }
|
| 285 |
|
| 286 |
|
| 287 | static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
|
| 288 | {
|
| 289 | const struct cred *cred = current_cred(), *tcred;
|
| 290 | struct mm_struct *mm;
|
| 291 | kuid_t caller_uid;
|
| 292 | kgid_t caller_gid;
|
| 293 |
|
| 294 | if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
|
| 295 | WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
|
| 296 | return -EPERM;
|
| 297 | }
|
| 298 |
|
| 299 | |
| 300 | * This check is used both for attaching with ptrace
|
| 301 | * and for allowing access to sensitive information in /proc.
|
| 302 | *
|
| 303 | * ptrace_attach denies several cases that /proc allows
|
| 304 | * because setting up the necessary parent/child relationship
|
| 305 | * or halting the specified task is impossible.
|
| 306 |
|
| 307 |
|
| 308 |
|
| 309 | if (same_thread_group(task, current))
|
| 310 | return 0;
|
| 311 | rcu_read_lock();
|
| 312 | if (mode & PTRACE_MODE_FSCREDS) {
|
| 313 | caller_uid = cred->fsuid;
|
| 314 | caller_gid = cred->fsgid;
|
| 315 | } else {
|
| 316 | |
| 317 | * Using the euid would make more sense here, but something
|
| 318 | * in userland might rely on the old behavior, and this
|
| 319 | * shouldn't be a security problem since
|
| 320 | * PTRACE_MODE_REALCREDS implies that the caller explicitly
|
| 321 | * used a syscall that requests access to another process
|
| 322 | * (and not a filesystem syscall to procfs).
|
| 323 |
|
| 324 | caller_uid = cred->uid;
|
| 325 | caller_gid = cred->gid;
|
| 326 | }
|
| 327 | tcred = __task_cred(task);
|
| 328 | if (uid_eq(caller_uid, tcred->euid) &&
|
| 329 | uid_eq(caller_uid, tcred->suid) &&
|
| 330 | uid_eq(caller_uid, tcred->uid) &&
|
| 331 | gid_eq(caller_gid, tcred->egid) &&
|
| 332 | gid_eq(caller_gid, tcred->sgid) &&
|
| 333 | gid_eq(caller_gid, tcred->gid))
|
| 334 | goto ok;
|
| 335 | if (ptrace_has_cap(tcred->user_ns, mode))
|
| 336 | goto ok;
|
| 337 | rcu_read_unlock();
|
| 338 | return -EPERM;
|
| 339 | ok:
|
| 340 | rcu_read_unlock();
|
| 341 | |
| 342 | * If a task drops privileges and becomes nondumpable (through a syscall
|
| 343 | * like setresuid()) while we are trying to access it, we must ensure
|
| 344 | * that the dumpability is read after the credentials; otherwise,
|
| 345 | * we may be able to attach to a task that we shouldn't be able to
|
| 346 | * attach to (as if the task had dropped privileges without becoming
|
| 347 | * nondumpable).
|
| 348 | * Pairs with a write barrier in commit_creds().
|
| 349 |
|
| 350 | smp_rmb();
|
| 351 | mm = task->mm;
|
| 352 | if (mm &&
|
| 353 | ((get_dumpable(mm) != SUID_DUMP_USER) &&
|
| 354 | !ptrace_has_cap(mm->user_ns, mode)))
|
| 355 | return -EPERM;
|
| 356 |
|
| 357 | return security_ptrace_access_check(task, mode);
|
| 358 | }
|
| 359 |
|
| 360 | bool ptrace_may_access(struct task_struct *task, unsigned int mode)
|
| 361 | {
|
| 362 | int err;
|
| 363 | task_lock(task);
|
| 364 | err = __ptrace_may_access(task, mode);
|
| 365 | task_unlock(task);
|
| 366 | return !err;
|
| 367 | }
|
| 368 |
|
| 369 | static int check_ptrace_options(unsigned long data)
|
| 370 | {
|
| 371 | if (data & ~(unsigned long)PTRACE_O_MASK)
|
| 372 | return -EINVAL;
|
| 373 |
|
| 374 | if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) {
|
| 375 | if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) ||
|
| 376 | !IS_ENABLED(CONFIG_SECCOMP))
|
| 377 | return -EINVAL;
|
| 378 |
|
| 379 | if (!capable(CAP_SYS_ADMIN))
|
| 380 | return -EPERM;
|
| 381 |
|
| 382 | if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED ||
|
| 383 | current->ptrace & PT_SUSPEND_SECCOMP)
|
| 384 | return -EPERM;
|
| 385 | }
|
| 386 | return 0;
|
| 387 | }
|
| 388 |
|
| 389 | static int ptrace_attach(struct task_struct *task, long request,
|
| 390 | unsigned long addr,
|
| 391 | unsigned long flags)
|
| 392 | {
|
| 393 | bool seize = (request == PTRACE_SEIZE);
|
| 394 | int retval;
|
| 395 |
|
| 396 | retval = -EIO;
|
| 397 | if (seize) {
|
| 398 | if (addr != 0)
|
| 399 | goto out;
|
| 400 | |
| 401 | * This duplicates the check in check_ptrace_options() because
|
| 402 | * ptrace_attach() and ptrace_setoptions() have historically
|
| 403 | * used different error codes for unknown ptrace options.
|
| 404 |
|
| 405 | if (flags & ~(unsigned long)PTRACE_O_MASK)
|
| 406 | goto out;
|
| 407 | retval = check_ptrace_options(flags);
|
| 408 | if (retval)
|
| 409 | return retval;
|
| 410 | flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
|
| 411 | } else {
|
| 412 | flags = PT_PTRACED;
|
| 413 | }
|
| 414 |
|
| 415 | audit_ptrace(task);
|
| 416 |
|
| 417 | retval = -EPERM;
|
| 418 | if (unlikely(task->flags & PF_KTHREAD))
|
| 419 | goto out;
|
| 420 | if (same_thread_group(task, current))
|
| 421 | goto out;
|
| 422 |
|
| 423 | |
| 424 | * Protect exec's credential calculations against our interference;
|
| 425 | * SUID, SGID and LSM creds get determined differently
|
| 426 | * under ptrace.
|
| 427 |
|
| 428 | retval = -ERESTARTNOINTR;
|
| 429 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
|
| 430 | goto out;
|
| 431 |
|
| 432 | task_lock(task);
|
| 433 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
|
| 434 | task_unlock(task);
|
| 435 | if (retval)
|
| 436 | goto unlock_creds;
|
| 437 |
|
| 438 | write_lock_irq(&tasklist_lock);
|
| 439 | retval = -EPERM;
|
| 440 | if (unlikely(task->exit_state))
|
| 441 | goto unlock_tasklist;
|
| 442 | if (task->ptrace)
|
| 443 | goto unlock_tasklist;
|
| 444 |
|
| 445 | task->ptrace = flags;
|
| 446 |
|
| 447 | ptrace_link(task, current);
|
| 448 |
|
| 449 |
|
| 450 | if (!seize)
|
| 451 | send_sig_info(SIGSTOP, SEND_SIG_PRIV, task);
|
| 452 |
|
| 453 | spin_lock(&task->sighand->siglock);
|
| 454 |
|
| 455 | |
| 456 | * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
|
| 457 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
|
| 458 | * will be cleared if the child completes the transition or any
|
| 459 | * event which clears the group stop states happens. We'll wait
|
| 460 | * for the transition to complete before returning from this
|
| 461 | * function.
|
| 462 | *
|
| 463 | * This hides STOPPED -> RUNNING -> TRACED transition from the
|
| 464 | * attaching thread but a different thread in the same group can
|
| 465 | * still observe the transient RUNNING state. IOW, if another
|
| 466 | * thread's WNOHANG wait(2) on the stopped tracee races against
|
| 467 | * ATTACH, the wait(2) may fail due to the transient RUNNING.
|
| 468 | *
|
| 469 | * The following task_is_stopped() test is safe as both transitions
|
| 470 | * in and out of STOPPED are protected by siglock.
|
| 471 |
|
| 472 | if (task_is_stopped(task) &&
|
| 473 | task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) {
|
| 474 | task->jobctl &= ~JOBCTL_STOPPED;
|
| 475 | signal_wake_up_state(task, __TASK_STOPPED);
|
| 476 | }
|
| 477 |
|
| 478 | spin_unlock(&task->sighand->siglock);
|
| 479 |
|
| 480 | retval = 0;
|
| 481 | unlock_tasklist:
|
| 482 | write_unlock_irq(&tasklist_lock);
|
| 483 | unlock_creds:
|
| 484 | mutex_unlock(&task->signal->cred_guard_mutex);
|
| 485 | out:
|
| 486 | if (!retval) {
|
| 487 | |
| 488 | * We do not bother to change retval or clear JOBCTL_TRAPPING
|
| 489 | * if wait_on_bit() was interrupted by SIGKILL. The tracer will
|
| 490 | * not return to user-mode, it will exit and clear this bit in
|
| 491 | * __ptrace_unlink() if it wasn't already cleared by the tracee;
|
| 492 | * and until then nobody can ptrace this task.
|
| 493 |
|
| 494 | wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE);
|
| 495 | proc_ptrace_connector(task, PTRACE_ATTACH);
|
| 496 | }
|
| 497 |
|
| 498 | return retval;
|
| 499 | }
|
| 500 |
|
| 501 | |
| 502 | * ptrace_traceme -- helper for PTRACE_TRACEME
|
| 503 | *
|
| 504 | * Performs checks and sets PT_PTRACED.
|
| 505 | * Should be used by all ptrace implementations for PTRACE_TRACEME.
|
| 506 |
|
| 507 | static int ptrace_traceme(void)
|
| 508 | {
|
| 509 | int ret = -EPERM;
|
| 510 |
|
| 511 | write_lock_irq(&tasklist_lock);
|
| 512 |
|
| 513 | if (!current->ptrace) {
|
| 514 | ret = security_ptrace_traceme(current->parent);
|
| 515 | |
| 516 | * Check PF_EXITING to ensure ->real_parent has not passed
|
| 517 | * exit_ptrace(). Otherwise we don't report the error but
|
| 518 | * pretend ->real_parent untraces us right after return.
|
| 519 |
|
| 520 | if (!ret && !(current->real_parent->flags & PF_EXITING)) {
|
| 521 | current->ptrace = PT_PTRACED;
|
| 522 | ptrace_link(current, current->real_parent);
|
| 523 | }
|
| 524 | }
|
| 525 | write_unlock_irq(&tasklist_lock);
|
| 526 |
|
| 527 | return ret;
|
| 528 | }
|
| 529 |
|
| 530 | |
| 531 | * Called with irqs disabled, returns true if childs should reap themselves.
|
| 532 |
|
| 533 | static int ignoring_children(struct sighand_struct *sigh)
|
| 534 | {
|
| 535 | int ret;
|
| 536 | spin_lock(&sigh->siglock);
|
| 537 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
|
| 538 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
|
| 539 | spin_unlock(&sigh->siglock);
|
| 540 | return ret;
|
| 541 | }
|
| 542 |
|
| 543 | |
| 544 | * Called with tasklist_lock held for writing.
|
| 545 | * Unlink a traced task, and clean it up if it was a traced zombie.
|
| 546 | * Return true if it needs to be reaped with release_task().
|
| 547 | * (We can't call release_task() here because we already hold tasklist_lock.)
|
| 548 | *
|
| 549 | * If it's a zombie, our attachedness prevented normal parent notification
|
| 550 | * or self-reaping. Do notification now if it would have happened earlier.
|
| 551 | * If it should reap itself, return true.
|
| 552 | *
|
| 553 | * If it's our own child, there is no notification to do. But if our normal
|
| 554 | * children self-reap, then this child was prevented by ptrace and we must
|
| 555 | * reap it now, in that case we must also wake up sub-threads sleeping in
|
| 556 | * do_wait().
|
| 557 |
|
| 558 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
|
| 559 | {
|
| 560 | bool dead;
|
| 561 |
|
| 562 | __ptrace_unlink(p);
|
| 563 |
|
| 564 | if (p->exit_state != EXIT_ZOMBIE)
|
| 565 | return false;
|
| 566 |
|
| 567 | dead = !thread_group_leader(p);
|
| 568 |
|
| 569 | if (!dead && thread_group_empty(p)) {
|
| 570 | if (!same_thread_group(p->real_parent, tracer))
|
| 571 | dead = do_notify_parent(p, p->exit_signal);
|
| 572 | else if (ignoring_children(tracer->sighand)) {
|
| 573 | __wake_up_parent(p, tracer);
|
| 574 | dead = true;
|
| 575 | }
|
| 576 | }
|
| 577 |
|
| 578 | if (dead)
|
| 579 | p->exit_state = EXIT_DEAD;
|
| 580 | return dead;
|
| 581 | }
|
| 582 |
|
| 583 | static int ptrace_detach(struct task_struct *child, unsigned int data)
|
| 584 | {
|
| 585 | if (!valid_signal(data))
|
| 586 | return -EIO;
|
| 587 |
|
| 588 |
|
| 589 | ptrace_disable(child);
|
| 590 |
|
| 591 | write_lock_irq(&tasklist_lock);
|
| 592 | |
| 593 | * We rely on ptrace_freeze_traced(). It can't be killed and
|
| 594 | * untraced by another thread, it can't be a zombie.
|
| 595 |
|
| 596 | WARN_ON(!child->ptrace || child->exit_state);
|
| 597 | |
| 598 | * tasklist_lock avoids the race with wait_task_stopped(), see
|
| 599 | * the comment in ptrace_resume().
|
| 600 |
|
| 601 | child->exit_code = data;
|
| 602 | __ptrace_detach(current, child);
|
| 603 | write_unlock_irq(&tasklist_lock);
|
| 604 |
|
| 605 | proc_ptrace_connector(child, PTRACE_DETACH);
|
| 606 |
|
| 607 | return 0;
|
| 608 | }
|
| 609 |
|
| 610 | |
| 611 | * Detach all tasks we were using ptrace on. Called with tasklist held
|
| 612 | * for writing.
|
| 613 |
|
| 614 | void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
|
| 615 | {
|
| 616 | struct task_struct *p, *n;
|
| 617 |
|
| 618 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
|
| 619 | if (unlikely(p->ptrace & PT_EXITKILL))
|
| 620 | send_sig_info(SIGKILL, SEND_SIG_PRIV, p);
|
| 621 |
|
| 622 | if (__ptrace_detach(tracer, p))
|
| 623 | list_add(&p->ptrace_entry, dead);
|
| 624 | }
|
| 625 | }
|
| 626 |
|
| 627 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
|
| 628 | {
|
| 629 | int copied = 0;
|
| 630 |
|
| 631 | while (len > 0) {
|
| 632 | char buf[128];
|
| 633 | int this_len, retval;
|
| 634 |
|
| 635 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
|
| 636 | retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE);
|
| 637 |
|
| 638 | if (!retval) {
|
| 639 | if (copied)
|
| 640 | break;
|
| 641 | return -EIO;
|
| 642 | }
|
| 643 | if (copy_to_user(dst, buf, retval))
|
| 644 | return -EFAULT;
|
| 645 | copied += retval;
|
| 646 | src += retval;
|
| 647 | dst += retval;
|
| 648 | len -= retval;
|
| 649 | }
|
| 650 | return copied;
|
| 651 | }
|
| 652 |
|
| 653 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
|
| 654 | {
|
| 655 | int copied = 0;
|
| 656 |
|
| 657 | while (len > 0) {
|
| 658 | char buf[128];
|
| 659 | int this_len, retval;
|
| 660 |
|
| 661 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
|
| 662 | if (copy_from_user(buf, src, this_len))
|
| 663 | return -EFAULT;
|
| 664 | retval = ptrace_access_vm(tsk, dst, buf, this_len,
|
| 665 | FOLL_FORCE | FOLL_WRITE);
|
| 666 | if (!retval) {
|
| 667 | if (copied)
|
| 668 | break;
|
| 669 | return -EIO;
|
| 670 | }
|
| 671 | copied += retval;
|
| 672 | src += retval;
|
| 673 | dst += retval;
|
| 674 | len -= retval;
|
| 675 | }
|
| 676 | return copied;
|
| 677 | }
|
| 678 |
|
| 679 | static int ptrace_setoptions(struct task_struct *child, unsigned long data)
|
| 680 | {
|
| 681 | unsigned flags;
|
| 682 | int ret;
|
| 683 |
|
| 684 | ret = check_ptrace_options(data);
|
| 685 | if (ret)
|
| 686 | return ret;
|
| 687 |
|
| 688 |
|
| 689 | flags = child->ptrace;
|
| 690 | flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
|
| 691 | flags |= (data << PT_OPT_FLAG_SHIFT);
|
| 692 | child->ptrace = flags;
|
| 693 |
|
| 694 | return 0;
|
| 695 | }
|
| 696 |
|
| 697 | static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info)
|
| 698 | {
|
| 699 | unsigned long flags;
|
| 700 | int error = -ESRCH;
|
| 701 |
|
| 702 | if (lock_task_sighand(child, &flags)) {
|
| 703 | error = -EINVAL;
|
| 704 | if (likely(child->last_siginfo != NULL)) {
|
| 705 | copy_siginfo(info, child->last_siginfo);
|
| 706 | error = 0;
|
| 707 | }
|
| 708 | unlock_task_sighand(child, &flags);
|
| 709 | }
|
| 710 | return error;
|
| 711 | }
|
| 712 |
|
| 713 | static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info)
|
| 714 | {
|
| 715 | unsigned long flags;
|
| 716 | int error = -ESRCH;
|
| 717 |
|
| 718 | if (lock_task_sighand(child, &flags)) {
|
| 719 | error = -EINVAL;
|
| 720 | if (likely(child->last_siginfo != NULL)) {
|
| 721 | copy_siginfo(child->last_siginfo, info);
|
| 722 | error = 0;
|
| 723 | }
|
| 724 | unlock_task_sighand(child, &flags);
|
| 725 | }
|
| 726 | return error;
|
| 727 | }
|
| 728 |
|
| 729 | static int ptrace_peek_siginfo(struct task_struct *child,
|
| 730 | unsigned long addr,
|
| 731 | unsigned long data)
|
| 732 | {
|
| 733 | struct ptrace_peeksiginfo_args arg;
|
| 734 | struct sigpending *pending;
|
| 735 | struct sigqueue *q;
|
| 736 | int ret, i;
|
| 737 |
|
| 738 | ret = copy_from_user(&arg, (void __user *) addr,
|
| 739 | sizeof(struct ptrace_peeksiginfo_args));
|
| 740 | if (ret)
|
| 741 | return -EFAULT;
|
| 742 |
|
| 743 | if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
|
| 744 | return -EINVAL;
|
| 745 |
|
| 746 | if (arg.nr < 0)
|
| 747 | return -EINVAL;
|
| 748 |
|
| 749 |
|
| 750 | if (arg.off > ULONG_MAX)
|
| 751 | return 0;
|
| 752 |
|
| 753 | if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
|
| 754 | pending = &child->signal->shared_pending;
|
| 755 | else
|
| 756 | pending = &child->pending;
|
| 757 |
|
| 758 | for (i = 0; i < arg.nr; ) {
|
| 759 | kernel_siginfo_t info;
|
| 760 | unsigned long off = arg.off + i;
|
| 761 | bool found = false;
|
| 762 |
|
| 763 | spin_lock_irq(&child->sighand->siglock);
|
| 764 | list_for_each_entry(q, &pending->list, list) {
|
| 765 | if (!off--) {
|
| 766 | found = true;
|
| 767 | copy_siginfo(&info, &q->info);
|
| 768 | break;
|
| 769 | }
|
| 770 | }
|
| 771 | spin_unlock_irq(&child->sighand->siglock);
|
| 772 |
|
| 773 | if (!found)
|
| 774 | break;
|
| 775 |
|
| 776 | #ifdef CONFIG_COMPAT
|
| 777 | if (unlikely(in_compat_syscall())) {
|
| 778 | compat_siginfo_t __user *uinfo = compat_ptr(data);
|
| 779 |
|
| 780 | if (copy_siginfo_to_user32(uinfo, &info)) {
|
| 781 | ret = -EFAULT;
|
| 782 | break;
|
| 783 | }
|
| 784 |
|
| 785 | } else
|
| 786 | #endif
|
| 787 | {
|
| 788 | siginfo_t __user *uinfo = (siginfo_t __user *) data;
|
| 789 |
|
| 790 | if (copy_siginfo_to_user(uinfo, &info)) {
|
| 791 | ret = -EFAULT;
|
| 792 | break;
|
| 793 | }
|
| 794 | }
|
| 795 |
|
| 796 | data += sizeof(siginfo_t);
|
| 797 | i++;
|
| 798 |
|
| 799 | if (signal_pending(current))
|
| 800 | break;
|
| 801 |
|
| 802 | cond_resched();
|
| 803 | }
|
| 804 |
|
| 805 | if (i > 0)
|
| 806 | return i;
|
| 807 |
|
| 808 | return ret;
|
| 809 | }
|
| 810 |
|
| 811 | #ifdef CONFIG_RSEQ
|
| 812 | static long ptrace_get_rseq_configuration(struct task_struct *task,
|
| 813 | unsigned long size, void __user *data)
|
| 814 | {
|
| 815 | struct ptrace_rseq_configuration conf = {
|
| 816 | .rseq_abi_pointer = (u64)(uintptr_t)task->rseq,
|
| 817 | .rseq_abi_size = task->rseq_len,
|
| 818 | .signature = task->rseq_sig,
|
| 819 | .flags = 0,
|
| 820 | };
|
| 821 |
|
| 822 | size = min_t(unsigned long, size, sizeof(conf));
|
| 823 | if (copy_to_user(data, &conf, size))
|
| 824 | return -EFAULT;
|
| 825 | return sizeof(conf);
|
| 826 | }
|
| 827 | #endif
|
| 828 |
|
| 829 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
|
| 830 |
|
| 831 | #ifdef PTRACE_SINGLEBLOCK
|
| 832 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
|
| 833 | #else
|
| 834 | #define is_singleblock(request) 0
|
| 835 | #endif
|
| 836 |
|
| 837 | #ifdef PTRACE_SYSEMU
|
| 838 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
|
| 839 | #else
|
| 840 | #define is_sysemu_singlestep(request) 0
|
| 841 | #endif
|
| 842 |
|
| 843 | static int ptrace_resume(struct task_struct *child, long request,
|
| 844 | unsigned long data)
|
| 845 | {
|
| 846 | if (!valid_signal(data))
|
| 847 | return -EIO;
|
| 848 |
|
| 849 | if (request == PTRACE_SYSCALL)
|
| 850 | set_task_syscall_work(child, SYSCALL_TRACE);
|
| 851 | else
|
| 852 | clear_task_syscall_work(child, SYSCALL_TRACE);
|
| 853 |
|
| 854 | #if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU)
|
| 855 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
|
| 856 | set_task_syscall_work(child, SYSCALL_EMU);
|
| 857 | else
|
| 858 | clear_task_syscall_work(child, SYSCALL_EMU);
|
| 859 | #endif
|
| 860 |
|
| 861 | if (is_singleblock(request)) {
|
| 862 | if (unlikely(!arch_has_block_step()))
|
| 863 | return -EIO;
|
| 864 | user_enable_block_step(child);
|
| 865 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
|
| 866 | if (unlikely(!arch_has_single_step()))
|
| 867 | return -EIO;
|
| 868 | user_enable_single_step(child);
|
| 869 | } else {
|
| 870 | user_disable_single_step(child);
|
| 871 | }
|
| 872 |
|
| 873 | |
| 874 | * Change ->exit_code and ->state under siglock to avoid the race
|
| 875 | * with wait_task_stopped() in between; a non-zero ->exit_code will
|
| 876 | * wrongly look like another report from tracee.
|
| 877 | *
|
| 878 | * Note that we need siglock even if ->exit_code == data and/or this
|
| 879 | * status was not reported yet, the new status must not be cleared by
|
| 880 | * wait_task_stopped() after resume.
|
| 881 |
|
| 882 | spin_lock_irq(&child->sighand->siglock);
|
| 883 | child->exit_code = data;
|
| 884 | child->jobctl &= ~JOBCTL_TRACED;
|
| 885 | wake_up_state(child, __TASK_TRACED);
|
| 886 | spin_unlock_irq(&child->sighand->siglock);
|
| 887 |
|
| 888 | return 0;
|
| 889 | }
|
| 890 |
|
| 891 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
|
| 892 |
|
| 893 | static const struct user_regset *
|
| 894 | find_regset(const struct user_regset_view *view, unsigned int type)
|
| 895 | {
|
| 896 | const struct user_regset *regset;
|
| 897 | int n;
|
| 898 |
|
| 899 | for (n = 0; n < view->n; ++n) {
|
| 900 | regset = view->regsets + n;
|
| 901 | if (regset->core_note_type == type)
|
| 902 | return regset;
|
| 903 | }
|
| 904 |
|
| 905 | return NULL;
|
| 906 | }
|
| 907 |
|
| 908 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
|
| 909 | struct iovec *kiov)
|
| 910 | {
|
| 911 | const struct user_regset_view *view = task_user_regset_view(task);
|
| 912 | const struct user_regset *regset = find_regset(view, type);
|
| 913 | int regset_no;
|
| 914 |
|
| 915 | if (!regset || (kiov->iov_len % regset->size) != 0)
|
| 916 | return -EINVAL;
|
| 917 |
|
| 918 | regset_no = regset - view->regsets;
|
| 919 | kiov->iov_len = min(kiov->iov_len,
|
| 920 | (__kernel_size_t) (regset->n * regset->size));
|
| 921 |
|
| 922 | if (req == PTRACE_GETREGSET)
|
| 923 | return copy_regset_to_user(task, view, regset_no, 0,
|
| 924 | kiov->iov_len, kiov->iov_base);
|
| 925 | else
|
| 926 | return copy_regset_from_user(task, view, regset_no, 0,
|
| 927 | kiov->iov_len, kiov->iov_base);
|
| 928 | }
|
| 929 |
|
| 930 | |
| 931 | * This is declared in linux/regset.h and defined in machine-dependent
|
| 932 | * code. We put the export here, near the primary machine-neutral use,
|
| 933 | * to ensure no machine forgets it.
|
| 934 |
|
| 935 | EXPORT_SYMBOL_GPL(task_user_regset_view);
|
| 936 |
|
| 937 | static unsigned long
|
| 938 | ptrace_get_syscall_info_entry(struct task_struct *child, struct pt_regs *regs,
|
| 939 | struct ptrace_syscall_info *info)
|
| 940 | {
|
| 941 | unsigned long args[ARRAY_SIZE(info->entry.args)];
|
| 942 | int i;
|
| 943 |
|
| 944 | info->op = PTRACE_SYSCALL_INFO_ENTRY;
|
| 945 | info->entry.nr = syscall_get_nr(child, regs);
|
| 946 | syscall_get_arguments(child, regs, args);
|
| 947 | for (i = 0; i < ARRAY_SIZE(args); i++)
|
| 948 | info->entry.args[i] = args[i];
|
| 949 |
|
| 950 |
|
| 951 | return offsetofend(struct ptrace_syscall_info, entry.args);
|
| 952 | }
|
| 953 |
|
| 954 | static unsigned long
|
| 955 | ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs,
|
| 956 | struct ptrace_syscall_info *info)
|
| 957 | {
|
| 958 | |
| 959 | * As struct ptrace_syscall_info.entry is currently a subset
|
| 960 | * of struct ptrace_syscall_info.seccomp, it makes sense to
|
| 961 | * initialize that subset using ptrace_get_syscall_info_entry().
|
| 962 | * This can be reconsidered in the future if these structures
|
| 963 | * diverge significantly enough.
|
| 964 |
|
| 965 | ptrace_get_syscall_info_entry(child, regs, info);
|
| 966 | info->op = PTRACE_SYSCALL_INFO_SECCOMP;
|
| 967 | info->seccomp.ret_data = child->ptrace_message;
|
| 968 |
|
| 969 |
|
| 970 | return offsetofend(struct ptrace_syscall_info, seccomp.ret_data);
|
| 971 | }
|
| 972 |
|
| 973 | static unsigned long
|
| 974 | ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs,
|
| 975 | struct ptrace_syscall_info *info)
|
| 976 | {
|
| 977 | info->op = PTRACE_SYSCALL_INFO_EXIT;
|
| 978 | info->exit.rval = syscall_get_error(child, regs);
|
| 979 | info->exit.is_error = !!info->exit.rval;
|
| 980 | if (!info->exit.is_error)
|
| 981 | info->exit.rval = syscall_get_return_value(child, regs);
|
| 982 |
|
| 983 |
|
| 984 | return offsetofend(struct ptrace_syscall_info, exit.is_error);
|
| 985 | }
|
| 986 |
|
| 987 | static int
|
| 988 | ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size,
|
| 989 | void __user *datavp)
|
| 990 | {
|
| 991 | struct pt_regs *regs = task_pt_regs(child);
|
| 992 | struct ptrace_syscall_info info = {
|
| 993 | .op = PTRACE_SYSCALL_INFO_NONE,
|
| 994 | .arch = syscall_get_arch(child),
|
| 995 | .instruction_pointer = instruction_pointer(regs),
|
| 996 | .stack_pointer = user_stack_pointer(regs),
|
| 997 | };
|
| 998 | unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry);
|
| 999 | unsigned long write_size;
|
| 1000 |
|
| 1001 | |
| 1002 | * This does not need lock_task_sighand() to access
|
| 1003 | * child->last_siginfo because ptrace_freeze_traced()
|
| 1004 | * called earlier by ptrace_check_attach() ensures that
|
| 1005 | * the tracee cannot go away and clear its last_siginfo.
|
| 1006 |
|
| 1007 | switch (child->last_siginfo ? child->last_siginfo->si_code : 0) {
|
| 1008 | case SIGTRAP | 0x80:
|
| 1009 | switch (child->ptrace_message) {
|
| 1010 | case PTRACE_EVENTMSG_SYSCALL_ENTRY:
|
| 1011 | actual_size = ptrace_get_syscall_info_entry(child, regs,
|
| 1012 | &info);
|
| 1013 | break;
|
| 1014 | case PTRACE_EVENTMSG_SYSCALL_EXIT:
|
| 1015 | actual_size = ptrace_get_syscall_info_exit(child, regs,
|
| 1016 | &info);
|
| 1017 | break;
|
| 1018 | }
|
| 1019 | break;
|
| 1020 | case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8):
|
| 1021 | actual_size = ptrace_get_syscall_info_seccomp(child, regs,
|
| 1022 | &info);
|
| 1023 | break;
|
| 1024 | }
|
| 1025 |
|
| 1026 | write_size = min(actual_size, user_size);
|
| 1027 | return copy_to_user(datavp, &info, write_size) ? -EFAULT : actual_size;
|
| 1028 | }
|
| 1029 | #endif
|
| 1030 |
|
| 1031 | int ptrace_request(struct task_struct *child, long request,
|
| 1032 | unsigned long addr, unsigned long data)
|
| 1033 | {
|
| 1034 | bool seized = child->ptrace & PT_SEIZED;
|
| 1035 | int ret = -EIO;
|
| 1036 | kernel_siginfo_t siginfo, *si;
|
| 1037 | void __user *datavp = (void __user *) data;
|
| 1038 | unsigned long __user *datalp = datavp;
|
| 1039 | unsigned long flags;
|
| 1040 |
|
| 1041 | switch (request) {
|
| 1042 | case PTRACE_PEEKTEXT:
|
| 1043 | case PTRACE_PEEKDATA:
|
| 1044 | return generic_ptrace_peekdata(child, addr, data);
|
| 1045 | case PTRACE_POKETEXT:
|
| 1046 | case PTRACE_POKEDATA:
|
| 1047 | return generic_ptrace_pokedata(child, addr, data);
|
| 1048 |
|
| 1049 | #ifdef PTRACE_OLDSETOPTIONS
|
| 1050 | case PTRACE_OLDSETOPTIONS:
|
| 1051 | #endif
|
| 1052 | case PTRACE_SETOPTIONS:
|
| 1053 | ret = ptrace_setoptions(child, data);
|
| 1054 | break;
|
| 1055 | case PTRACE_GETEVENTMSG:
|
| 1056 | ret = put_user(child->ptrace_message, datalp);
|
| 1057 | break;
|
| 1058 |
|
| 1059 | case PTRACE_PEEKSIGINFO:
|
| 1060 | ret = ptrace_peek_siginfo(child, addr, data);
|
| 1061 | break;
|
| 1062 |
|
| 1063 | case PTRACE_GETSIGINFO:
|
| 1064 | ret = ptrace_getsiginfo(child, &siginfo);
|
| 1065 | if (!ret)
|
| 1066 | ret = copy_siginfo_to_user(datavp, &siginfo);
|
| 1067 | break;
|
| 1068 |
|
| 1069 | case PTRACE_SETSIGINFO:
|
| 1070 | ret = copy_siginfo_from_user(&siginfo, datavp);
|
| 1071 | if (!ret)
|
| 1072 | ret = ptrace_setsiginfo(child, &siginfo);
|
| 1073 | break;
|
| 1074 |
|
| 1075 | case PTRACE_GETSIGMASK: {
|
| 1076 | sigset_t *mask;
|
| 1077 |
|
| 1078 | if (addr != sizeof(sigset_t)) {
|
| 1079 | ret = -EINVAL;
|
| 1080 | break;
|
| 1081 | }
|
| 1082 |
|
| 1083 | if (test_tsk_restore_sigmask(child))
|
| 1084 | mask = &child->saved_sigmask;
|
| 1085 | else
|
| 1086 | mask = &child->blocked;
|
| 1087 |
|
| 1088 | if (copy_to_user(datavp, mask, sizeof(sigset_t)))
|
| 1089 | ret = -EFAULT;
|
| 1090 | else
|
| 1091 | ret = 0;
|
| 1092 |
|
| 1093 | break;
|
| 1094 | }
|
| 1095 |
|
| 1096 | case PTRACE_SETSIGMASK: {
|
| 1097 | sigset_t new_set;
|
| 1098 |
|
| 1099 | if (addr != sizeof(sigset_t)) {
|
| 1100 | ret = -EINVAL;
|
| 1101 | break;
|
| 1102 | }
|
| 1103 |
|
| 1104 | if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
|
| 1105 | ret = -EFAULT;
|
| 1106 | break;
|
| 1107 | }
|
| 1108 |
|
| 1109 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
|
| 1110 |
|
| 1111 | |
| 1112 | * Every thread does recalc_sigpending() after resume, so
|
| 1113 | * retarget_shared_pending() and recalc_sigpending() are not
|
| 1114 | * called here.
|
| 1115 |
|
| 1116 | spin_lock_irq(&child->sighand->siglock);
|
| 1117 | child->blocked = new_set;
|
| 1118 | spin_unlock_irq(&child->sighand->siglock);
|
| 1119 |
|
| 1120 | clear_tsk_restore_sigmask(child);
|
| 1121 |
|
| 1122 | ret = 0;
|
| 1123 | break;
|
| 1124 | }
|
| 1125 |
|
| 1126 | case PTRACE_INTERRUPT:
|
| 1127 | |
| 1128 | * Stop tracee without any side-effect on signal or job
|
| 1129 | * control. At least one trap is guaranteed to happen
|
| 1130 | * after this request. If @child is already trapped, the
|
| 1131 | * current trap is not disturbed and another trap will
|
| 1132 | * happen after the current trap is ended with PTRACE_CONT.
|
| 1133 | *
|
| 1134 | * The actual trap might not be PTRACE_EVENT_STOP trap but
|
| 1135 | * the pending condition is cleared regardless.
|
| 1136 |
|
| 1137 | if (unlikely(!seized || !lock_task_sighand(child, &flags)))
|
| 1138 | break;
|
| 1139 |
|
| 1140 | |
| 1141 | * INTERRUPT doesn't disturb existing trap sans one
|
| 1142 | * exception. If ptracer issued LISTEN for the current
|
| 1143 | * STOP, this INTERRUPT should clear LISTEN and re-trap
|
| 1144 | * tracee into STOP.
|
| 1145 |
|
| 1146 | if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
|
| 1147 | ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
|
| 1148 |
|
| 1149 | unlock_task_sighand(child, &flags);
|
| 1150 | ret = 0;
|
| 1151 | break;
|
| 1152 |
|
| 1153 | case PTRACE_LISTEN:
|
| 1154 | |
| 1155 | * Listen for events. Tracee must be in STOP. It's not
|
| 1156 | * resumed per-se but is not considered to be in TRACED by
|
| 1157 | * wait(2) or ptrace(2). If an async event (e.g. group
|
| 1158 | * stop state change) happens, tracee will enter STOP trap
|
| 1159 | * again. Alternatively, ptracer can issue INTERRUPT to
|
| 1160 | * finish listening and re-trap tracee into STOP.
|
| 1161 |
|
| 1162 | if (unlikely(!seized || !lock_task_sighand(child, &flags)))
|
| 1163 | break;
|
| 1164 |
|
| 1165 | si = child->last_siginfo;
|
| 1166 | if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
|
| 1167 | child->jobctl |= JOBCTL_LISTENING;
|
| 1168 | |
| 1169 | * If NOTIFY is set, it means event happened between
|
| 1170 | * start of this trap and now. Trigger re-trap.
|
| 1171 |
|
| 1172 | if (child->jobctl & JOBCTL_TRAP_NOTIFY)
|
| 1173 | ptrace_signal_wake_up(child, true);
|
| 1174 | ret = 0;
|
| 1175 | }
|
| 1176 | unlock_task_sighand(child, &flags);
|
| 1177 | break;
|
| 1178 |
|
| 1179 | case PTRACE_DETACH:
|
| 1180 | ret = ptrace_detach(child, data);
|
| 1181 | break;
|
| 1182 |
|
| 1183 | #ifdef CONFIG_BINFMT_ELF_FDPIC
|
| 1184 | case PTRACE_GETFDPIC: {
|
| 1185 | struct mm_struct *mm = get_task_mm(child);
|
| 1186 | unsigned long tmp = 0;
|
| 1187 |
|
| 1188 | ret = -ESRCH;
|
| 1189 | if (!mm)
|
| 1190 | break;
|
| 1191 |
|
| 1192 | switch (addr) {
|
| 1193 | case PTRACE_GETFDPIC_EXEC:
|
| 1194 | tmp = mm->context.exec_fdpic_loadmap;
|
| 1195 | break;
|
| 1196 | case PTRACE_GETFDPIC_INTERP:
|
| 1197 | tmp = mm->context.interp_fdpic_loadmap;
|
| 1198 | break;
|
| 1199 | default:
|
| 1200 | break;
|
| 1201 | }
|
| 1202 | mmput(mm);
|
| 1203 |
|
| 1204 | ret = put_user(tmp, datalp);
|
| 1205 | break;
|
| 1206 | }
|
| 1207 | #endif
|
| 1208 |
|
| 1209 | case PTRACE_SINGLESTEP:
|
| 1210 | #ifdef PTRACE_SINGLEBLOCK
|
| 1211 | case PTRACE_SINGLEBLOCK:
|
| 1212 | #endif
|
| 1213 | #ifdef PTRACE_SYSEMU
|
| 1214 | case PTRACE_SYSEMU:
|
| 1215 | case PTRACE_SYSEMU_SINGLESTEP:
|
| 1216 | #endif
|
| 1217 | case PTRACE_SYSCALL:
|
| 1218 | case PTRACE_CONT:
|
| 1219 | return ptrace_resume(child, request, data);
|
| 1220 |
|
| 1221 | case PTRACE_KILL:
|
| 1222 | send_sig_info(SIGKILL, SEND_SIG_NOINFO, child);
|
| 1223 | return 0;
|
| 1224 |
|
| 1225 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
|
| 1226 | case PTRACE_GETREGSET:
|
| 1227 | case PTRACE_SETREGSET: {
|
| 1228 | struct iovec kiov;
|
| 1229 | struct iovec __user *uiov = datavp;
|
| 1230 |
|
| 1231 | if (!access_ok(uiov, sizeof(*uiov)))
|
| 1232 | return -EFAULT;
|
| 1233 |
|
| 1234 | if (__get_user(kiov.iov_base, &uiov->iov_base) ||
|
| 1235 | __get_user(kiov.iov_len, &uiov->iov_len))
|
| 1236 | return -EFAULT;
|
| 1237 |
|
| 1238 | ret = ptrace_regset(child, request, addr, &kiov);
|
| 1239 | if (!ret)
|
| 1240 | ret = __put_user(kiov.iov_len, &uiov->iov_len);
|
| 1241 | break;
|
| 1242 | }
|
| 1243 |
|
| 1244 | case PTRACE_GET_SYSCALL_INFO:
|
| 1245 | ret = ptrace_get_syscall_info(child, addr, datavp);
|
| 1246 | break;
|
| 1247 | #endif
|
| 1248 |
|
| 1249 | case PTRACE_SECCOMP_GET_FILTER:
|
| 1250 | ret = seccomp_get_filter(child, addr, datavp);
|
| 1251 | break;
|
| 1252 |
|
| 1253 | case PTRACE_SECCOMP_GET_METADATA:
|
| 1254 | ret = seccomp_get_metadata(child, addr, datavp);
|
| 1255 | break;
|
| 1256 |
|
| 1257 | #ifdef CONFIG_RSEQ
|
| 1258 | case PTRACE_GET_RSEQ_CONFIGURATION:
|
| 1259 | ret = ptrace_get_rseq_configuration(child, addr, datavp);
|
| 1260 | break;
|
| 1261 | #endif
|
| 1262 |
|
| 1263 | case PTRACE_SET_SYSCALL_USER_DISPATCH_CONFIG:
|
| 1264 | ret = syscall_user_dispatch_set_config(child, addr, datavp);
|
| 1265 | break;
|
| 1266 |
|
| 1267 | case PTRACE_GET_SYSCALL_USER_DISPATCH_CONFIG:
|
| 1268 | ret = syscall_user_dispatch_get_config(child, addr, datavp);
|
| 1269 | break;
|
| 1270 |
|
| 1271 | default:
|
| 1272 | break;
|
| 1273 | }
|
| 1274 |
|
| 1275 | return ret;
|
| 1276 | }
|
| 1277 |
|
| 1278 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
|
| 1279 | unsigned long, data)
|
| 1280 | {
|
| 1281 | struct task_struct *child;
|
| 1282 | long ret;
|
| 1283 |
|
| 1284 | if (request == PTRACE_TRACEME) {
|
| 1285 | ret = ptrace_traceme();
|
| 1286 | goto out;
|
| 1287 | }
|
| 1288 |
|
| 1289 | child = find_get_task_by_vpid(pid);
|
| 1290 | if (!child) {
|
| 1291 | ret = -ESRCH;
|
| 1292 | goto out;
|
| 1293 | }
|
| 1294 |
|
| 1295 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
|
| 1296 | ret = ptrace_attach(child, request, addr, data);
|
| 1297 | goto out_put_task_struct;
|
| 1298 | }
|
| 1299 |
|
| 1300 | ret = ptrace_check_attach(child, request == PTRACE_KILL ||
|
| 1301 | request == PTRACE_INTERRUPT);
|
| 1302 | if (ret < 0)
|
| 1303 | goto out_put_task_struct;
|
| 1304 |
|
| 1305 | ret = arch_ptrace(child, request, addr, data);
|
| 1306 | if (ret || request != PTRACE_DETACH)
|
| 1307 | ptrace_unfreeze_traced(child);
|
| 1308 |
|
| 1309 | out_put_task_struct:
|
| 1310 | put_task_struct(child);
|
| 1311 | out:
|
| 1312 | return ret;
|
| 1313 | }
|
| 1314 |
|
| 1315 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
|
| 1316 | unsigned long data)
|
| 1317 | {
|
| 1318 | unsigned long tmp;
|
| 1319 | int copied;
|
| 1320 |
|
| 1321 | copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE);
|
| 1322 | if (copied != sizeof(tmp))
|
| 1323 | return -EIO;
|
| 1324 | return put_user(tmp, (unsigned long __user *)data);
|
| 1325 | }
|
| 1326 |
|
| 1327 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
|
| 1328 | unsigned long data)
|
| 1329 | {
|
| 1330 | int copied;
|
| 1331 |
|
| 1332 | copied = ptrace_access_vm(tsk, addr, &data, sizeof(data),
|
| 1333 | FOLL_FORCE | FOLL_WRITE);
|
| 1334 | return (copied == sizeof(data)) ? 0 : -EIO;
|
| 1335 | }
|
| 1336 |
|
| 1337 | #if defined CONFIG_COMPAT
|
| 1338 |
|
| 1339 | int compat_ptrace_request(struct task_struct *child, compat_long_t request,
|
| 1340 | compat_ulong_t addr, compat_ulong_t data)
|
| 1341 | {
|
| 1342 | compat_ulong_t __user *datap = compat_ptr(data);
|
| 1343 | compat_ulong_t word;
|
| 1344 | kernel_siginfo_t siginfo;
|
| 1345 | int ret;
|
| 1346 |
|
| 1347 | switch (request) {
|
| 1348 | case PTRACE_PEEKTEXT:
|
| 1349 | case PTRACE_PEEKDATA:
|
| 1350 | ret = ptrace_access_vm(child, addr, &word, sizeof(word),
|
| 1351 | FOLL_FORCE);
|
| 1352 | if (ret != sizeof(word))
|
| 1353 | ret = -EIO;
|
| 1354 | else
|
| 1355 | ret = put_user(word, datap);
|
| 1356 | break;
|
| 1357 |
|
| 1358 | case PTRACE_POKETEXT:
|
| 1359 | case PTRACE_POKEDATA:
|
| 1360 | ret = ptrace_access_vm(child, addr, &data, sizeof(data),
|
| 1361 | FOLL_FORCE | FOLL_WRITE);
|
| 1362 | ret = (ret != sizeof(data) ? -EIO : 0);
|
| 1363 | break;
|
| 1364 |
|
| 1365 | case PTRACE_GETEVENTMSG:
|
| 1366 | ret = put_user((compat_ulong_t) child->ptrace_message, datap);
|
| 1367 | break;
|
| 1368 |
|
| 1369 | case PTRACE_GETSIGINFO:
|
| 1370 | ret = ptrace_getsiginfo(child, &siginfo);
|
| 1371 | if (!ret)
|
| 1372 | ret = copy_siginfo_to_user32(
|
| 1373 | (struct compat_siginfo __user *) datap,
|
| 1374 | &siginfo);
|
| 1375 | break;
|
| 1376 |
|
| 1377 | case PTRACE_SETSIGINFO:
|
| 1378 | ret = copy_siginfo_from_user32(
|
| 1379 | &siginfo, (struct compat_siginfo __user *) datap);
|
| 1380 | if (!ret)
|
| 1381 | ret = ptrace_setsiginfo(child, &siginfo);
|
| 1382 | break;
|
| 1383 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
|
| 1384 | case PTRACE_GETREGSET:
|
| 1385 | case PTRACE_SETREGSET:
|
| 1386 | {
|
| 1387 | struct iovec kiov;
|
| 1388 | struct compat_iovec __user *uiov =
|
| 1389 | (struct compat_iovec __user *) datap;
|
| 1390 | compat_uptr_t ptr;
|
| 1391 | compat_size_t len;
|
| 1392 |
|
| 1393 | if (!access_ok(uiov, sizeof(*uiov)))
|
| 1394 | return -EFAULT;
|
| 1395 |
|
| 1396 | if (__get_user(ptr, &uiov->iov_base) ||
|
| 1397 | __get_user(len, &uiov->iov_len))
|
| 1398 | return -EFAULT;
|
| 1399 |
|
| 1400 | kiov.iov_base = compat_ptr(ptr);
|
| 1401 | kiov.iov_len = len;
|
| 1402 |
|
| 1403 | ret = ptrace_regset(child, request, addr, &kiov);
|
| 1404 | if (!ret)
|
| 1405 | ret = __put_user(kiov.iov_len, &uiov->iov_len);
|
| 1406 | break;
|
| 1407 | }
|
| 1408 | #endif
|
| 1409 |
|
| 1410 | default:
|
| 1411 | ret = ptrace_request(child, request, addr, data);
|
| 1412 | }
|
| 1413 |
|
| 1414 | return ret;
|
| 1415 | }
|
| 1416 |
|
| 1417 | COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
|
| 1418 | compat_long_t, addr, compat_long_t, data)
|
| 1419 | {
|
| 1420 | struct task_struct *child;
|
| 1421 | long ret;
|
| 1422 |
|
| 1423 | if (request == PTRACE_TRACEME) {
|
| 1424 | ret = ptrace_traceme();
|
| 1425 | goto out;
|
| 1426 | }
|
| 1427 |
|
| 1428 | child = find_get_task_by_vpid(pid);
|
| 1429 | if (!child) {
|
| 1430 | ret = -ESRCH;
|
| 1431 | goto out;
|
| 1432 | }
|
| 1433 |
|
| 1434 | if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
|
| 1435 | ret = ptrace_attach(child, request, addr, data);
|
| 1436 | goto out_put_task_struct;
|
| 1437 | }
|
| 1438 |
|
| 1439 | ret = ptrace_check_attach(child, request == PTRACE_KILL ||
|
| 1440 | request == PTRACE_INTERRUPT);
|
| 1441 | if (!ret) {
|
| 1442 | ret = compat_arch_ptrace(child, request, addr, data);
|
| 1443 | if (ret || request != PTRACE_DETACH)
|
| 1444 | ptrace_unfreeze_traced(child);
|
| 1445 | }
|
| 1446 |
|
| 1447 | out_put_task_struct:
|
| 1448 | put_task_struct(child);
|
| 1449 | out:
|
| 1450 | return ret;
|
| 1451 | }
|
| 1452 | #endif
|