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Thomas Gleixner457c8992019-05-19 13:08:55 +01001// SPDX-License-Identifier: GPL-2.0-only
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
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
Randy.Dunlapc59ede72006-01-11 12:17:46 -080011#include <linux/capability.h>
Paul Gortmaker9984de12011-05-23 14:51:41 -040012#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/sched.h>
Ingo Molnar6e84f312017-02-08 18:51:29 +010014#include <linux/sched/mm.h>
Ingo Molnarf7ccbae2017-02-08 18:51:30 +010015#include <linux/sched/coredump.h>
Ingo Molnar29930022017-02-08 18:51:36 +010016#include <linux/sched/task.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/errno.h>
18#include <linux/mm.h>
19#include <linux/highmem.h>
20#include <linux/pagemap.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/ptrace.h>
22#include <linux/security.h>
Jesper Juhl7ed20e12005-05-01 08:59:14 -070023#include <linux/signal.h>
Kent Overstreeta27bb332013-05-07 16:19:08 -070024#include <linux/uio.h>
Al Viroa5cb0132007-03-20 13:58:35 -040025#include <linux/audit.h>
Pavel Emelyanovb4888932007-10-18 23:40:14 -070026#include <linux/pid_namespace.h>
Adrian Bunkf17d30a2008-02-06 01:36:44 -080027#include <linux/syscalls.h>
Roland McGrath3a709702009-04-07 23:21:06 -070028#include <linux/uaccess.h>
Suresh Siddha2225a122010-02-11 11:51:00 -080029#include <linux/regset.h>
Frederic Weisbeckerbf26c012011-04-07 16:53:20 +020030#include <linux/hw_breakpoint.h>
Vladimir Zapolskiyf701e5b2011-07-15 20:45:18 +030031#include <linux/cn_proc.h>
Andrey Vagin84c751b2013-04-30 15:27:59 -070032#include <linux/compat.h>
Andrei Vaginfcfc2aa02019-03-28 20:44:13 -070033#include <linux/sched/signal.h>
Piotr Figiel90f093f2021-02-26 14:51:56 +010034#include <linux/minmax.h>
Gregory Price3f679872023-04-07 13:18:33 -040035#include <linux/syscall_user_dispatch.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
Elvira Khabirova201766a2019-07-16 16:29:42 -070037#include <asm/syscall.h> /* for syscall_get_* */
38
Eric W. Biederman84d77d32016-11-22 12:06:50 -060039/*
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 */
44int 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
Lorenzo Stoakesc43cfa42023-10-03 00:14:51 +010062 ret = access_remote_vm(mm, addr, buf, len, gup_flags);
Eric W. Biederman84d77d32016-11-22 12:06:50 -060063 mmput(mm);
64
65 return ret;
66}
67
Markus Metzgerbf53de92008-12-19 15:10:24 +010068
Eric W. Biedermanc70d9d82017-05-22 15:40:12 -050069void __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
Markus Metzgerbf53de92008-12-19 15:10:24 +010078/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 * 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 */
Eric W. Biedermanc70d9d82017-05-22 15:40:12 -050084static void ptrace_link(struct task_struct *child, struct task_struct *new_parent)
Linus Torvalds1da177e2005-04-16 15:20:36 -070085{
Jann Horn6994eef2019-07-04 17:32:23 +020086 __ptrace_link(child, new_parent, current_cred());
Linus Torvalds1da177e2005-04-16 15:20:36 -070087}
Roland McGrath3a709702009-04-07 23:21:06 -070088
Tejun Heoe3bd0582011-03-23 10:37:01 +010089/**
90 * __ptrace_unlink - unlink ptracee and restore its execution state
91 * @child: ptracee to be unlinked
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 *
Tejun Heo0e9f0a42011-03-23 10:37:01 +010093 * 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.
Tejun Heoe3bd0582011-03-23 10:37:01 +0100113 *
114 * CONTEXT:
115 * write_lock_irq(tasklist_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 */
Ingo Molnar36c8b582006-07-03 00:25:41 -0700117void __ptrace_unlink(struct task_struct *child)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118{
Eric W. Biederman64b875f2016-11-14 18:48:07 -0600119 const struct cred *old_cred;
Oleg Nesterov5ecfbae2006-02-15 22:50:10 +0300120 BUG_ON(!child->ptrace);
121
Gabriel Krisman Bertazi64c19ba2020-11-16 12:42:02 -0500122 clear_task_syscall_work(child, SYSCALL_TRACE);
Gabriel Krisman Bertazi64eb35f2020-11-16 12:42:03 -0500123#if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU)
124 clear_task_syscall_work(child, SYSCALL_EMU);
Sudeep Holla15532fd2019-05-23 10:06:15 +0100125#endif
Ales Novak0a5bf402016-10-11 13:53:46 -0700126
Roland McGrathf4700212008-03-24 18:36:23 -0700127 child->parent = child->real_parent;
128 list_del_init(&child->ptrace_entry);
Eric W. Biederman64b875f2016-11-14 18:48:07 -0600129 old_cred = child->ptracer_cred;
130 child->ptracer_cred = NULL;
131 put_cred(old_cred);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 spin_lock(&child->sighand->siglock);
Oleg Nesterov1333ab02016-03-22 14:25:33 -0700134 child->ptrace = 0;
Tejun Heo0e9f0a42011-03-23 10:37:01 +0100135 /*
Tejun Heo73ddff22011-06-14 11:20:14 +0200136 * 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 /*
Tejun Heoa8f072c2011-06-02 11:13:59 +0200143 * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
Tejun Heo0e9f0a42011-03-23 10:37:01 +0100144 * @child isn't dead.
145 */
146 if (!(child->flags & PF_EXITING) &&
147 (child->signal->flags & SIGNAL_STOP_STOPPED ||
Oleg Nesterov27bbb2a2023-11-21 17:26:50 +0100148 child->signal->group_stop_count))
Tejun Heoa8f072c2011-06-02 11:13:59 +0200149 child->jobctl |= JOBCTL_STOP_PENDING;
Tejun Heo0e9f0a42011-03-23 10:37:01 +0100150
151 /*
152 * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
153 * @child in the butt. Note that @resume should be used iff @child
154 * is in TASK_TRACED; otherwise, we might unduly disrupt
155 * TASK_KILLABLE sleeps.
156 */
Tejun Heoa8f072c2011-06-02 11:13:59 +0200157 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
Oleg Nesterov910ffdb12013-01-21 20:47:41 +0100158 ptrace_signal_wake_up(child, true);
Tejun Heo0e9f0a42011-03-23 10:37:01 +0100159
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 spin_unlock(&child->sighand->siglock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161}
162
Oleg Nesterovdbb5afa2021-05-12 15:33:08 +0200163static bool looks_like_a_spurious_pid(struct task_struct *task)
164{
165 if (task->exit_code != ((PTRACE_EVENT_EXEC << 8) | SIGTRAP))
166 return false;
167
168 if (task_pid_vnr(task) == task->ptrace_message)
169 return false;
170 /*
171 * The tracee changed its pid but the PTRACE_EVENT_EXEC event
172 * was not wait()'ed, most probably debugger targets the old
173 * leader which was destroyed in de_thread().
174 */
175 return true;
176}
177
Peter Zijlstra31cae1e2022-05-03 15:57:47 -0500178/*
179 * Ensure that nothing can wake it up, even SIGKILL
180 *
181 * A task is switched to this state while a ptrace operation is in progress;
182 * such that the ptrace operation is uninterruptible.
183 */
Oleg Nesterov9899d112013-01-21 20:48:00 +0100184static bool ptrace_freeze_traced(struct task_struct *task)
185{
186 bool ret = false;
187
188 /* Lockless, nobody but us can set this flag */
189 if (task->jobctl & JOBCTL_LISTENING)
190 return ret;
191
192 spin_lock_irq(&task->sighand->siglock);
Oleg Nesterovdbb5afa2021-05-12 15:33:08 +0200193 if (task_is_traced(task) && !looks_like_a_spurious_pid(task) &&
194 !__fatal_signal_pending(task)) {
Eric W. Biederman2500ad12022-04-29 08:43:34 -0500195 task->jobctl |= JOBCTL_PTRACE_FROZEN;
Oleg Nesterov9899d112013-01-21 20:48:00 +0100196 ret = true;
197 }
198 spin_unlock_irq(&task->sighand->siglock);
199
200 return ret;
201}
202
203static void ptrace_unfreeze_traced(struct task_struct *task)
204{
Eric W. Biederman2500ad12022-04-29 08:43:34 -0500205 unsigned long flags;
Oleg Nesterov9899d112013-01-21 20:48:00 +0100206
bsegall@google.com5402e972017-04-07 16:04:51 -0700207 /*
Eric W. Biederman2500ad12022-04-29 08:43:34 -0500208 * The child may be awake and may have cleared
209 * JOBCTL_PTRACE_FROZEN (see ptrace_resume). The child will
210 * not set JOBCTL_PTRACE_FROZEN or enter __TASK_TRACED anew.
bsegall@google.com5402e972017-04-07 16:04:51 -0700211 */
Eric W. Biederman2500ad12022-04-29 08:43:34 -0500212 if (lock_task_sighand(task, &flags)) {
213 task->jobctl &= ~JOBCTL_PTRACE_FROZEN;
Peter Zijlstra31cae1e2022-05-03 15:57:47 -0500214 if (__fatal_signal_pending(task)) {
Sven Schnellede2a3472022-07-06 12:16:25 +0200215 task->jobctl &= ~JOBCTL_TRACED;
bsegall@google.com5402e972017-04-07 16:04:51 -0700216 wake_up_state(task, __TASK_TRACED);
Peter Zijlstra31cae1e2022-05-03 15:57:47 -0500217 }
Eric W. Biederman2500ad12022-04-29 08:43:34 -0500218 unlock_task_sighand(task, &flags);
bsegall@google.com5402e972017-04-07 16:04:51 -0700219 }
Oleg Nesterov9899d112013-01-21 20:48:00 +0100220}
221
Tejun Heo755e2762011-06-02 11:13:59 +0200222/**
223 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
224 * @child: ptracee to check for
225 * @ignore_state: don't check whether @child is currently %TASK_TRACED
226 *
227 * Check whether @child is being ptraced by %current and ready for further
228 * ptrace operations. If @ignore_state is %false, @child also should be in
229 * %TASK_TRACED state and on return the child is guaranteed to be traced
230 * and not executing. If @ignore_state is %true, @child can be in any
231 * state.
232 *
233 * CONTEXT:
234 * Grabs and releases tasklist_lock and @child->sighand->siglock.
235 *
236 * RETURNS:
237 * 0 on success, -ESRCH if %child is not ready.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 */
Oleg Nesterovedea0d02013-01-20 20:25:47 +0100239static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240{
241 int ret = -ESRCH;
242
243 /*
244 * We take the read lock around doing both checks to close a
245 * possible race where someone else was tracing our child and
246 * detached between these two checks. After this locked check,
247 * we are sure that this is our traced child and that can only
248 * be changed by us so it's not changing right after this.
249 */
250 read_lock(&tasklist_lock);
Oleg Nesterov9899d112013-01-21 20:48:00 +0100251 if (child->ptrace && child->parent == current) {
Oleg Nesterovc0c0b642008-02-08 04:19:00 -0800252 /*
253 * child->sighand can't be NULL, release_task()
254 * does ptrace_unlink() before __exit_signal().
255 */
Oleg Nesterov9899d112013-01-21 20:48:00 +0100256 if (ignore_state || ptrace_freeze_traced(child))
Oleg Nesterov321fb562011-04-01 20:13:01 +0200257 ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 }
259 read_unlock(&tasklist_lock);
260
Eric W. Biederman7b0fe132022-05-05 12:25:36 -0500261 if (!ret && !ignore_state &&
Peter Zijlstraf5d39b02022-08-22 13:18:22 +0200262 WARN_ON_ONCE(!wait_task_inactive(child, __TASK_TRACED|TASK_FROZEN)))
Eric W. Biederman7b0fe132022-05-05 12:25:36 -0500263 ret = -ESRCH;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 return ret;
266}
267
Mickaël Salaüncf237052020-10-30 13:38:48 +0100268static bool ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
Eric Paris69f594a2012-01-03 12:25:15 -0500269{
270 if (mode & PTRACE_MODE_NOAUDIT)
Mickaël Salaüncf237052020-10-30 13:38:48 +0100271 return ns_capable_noaudit(ns, CAP_SYS_PTRACE);
272 return ns_capable(ns, CAP_SYS_PTRACE);
Eric Paris69f594a2012-01-03 12:25:15 -0500273}
274
Tetsuo Handa9f997982012-07-31 20:37:00 +0900275/* Returns 0 on success, -errno on denial. */
276static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
Miklos Szerediab8d11b2005-09-06 15:18:24 -0700277{
David Howellsc69e8d92008-11-14 10:39:19 +1100278 const struct cred *cred = current_cred(), *tcred;
Eric W. Biedermanbfedb582016-10-13 21:23:16 -0500279 struct mm_struct *mm;
Jann Horncaaee622016-01-20 15:00:04 -0800280 kuid_t caller_uid;
281 kgid_t caller_gid;
282
283 if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
284 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
285 return -EPERM;
286 }
David Howellsb6dff3e2008-11-14 10:39:16 +1100287
Eric W. Biedermandf26c402006-06-26 00:25:59 -0700288 /* May we inspect the given task?
289 * This check is used both for attaching with ptrace
290 * and for allowing access to sensitive information in /proc.
291 *
292 * ptrace_attach denies several cases that /proc allows
293 * because setting up the necessary parent/child relationship
294 * or halting the specified task is impossible.
295 */
Jann Horncaaee622016-01-20 15:00:04 -0800296
Eric W. Biedermandf26c402006-06-26 00:25:59 -0700297 /* Don't let security modules deny introspection */
Mark Grondona73af9632013-09-11 14:24:31 -0700298 if (same_thread_group(task, current))
Eric W. Biedermandf26c402006-06-26 00:25:59 -0700299 return 0;
David Howellsc69e8d92008-11-14 10:39:19 +1100300 rcu_read_lock();
Jann Horncaaee622016-01-20 15:00:04 -0800301 if (mode & PTRACE_MODE_FSCREDS) {
302 caller_uid = cred->fsuid;
303 caller_gid = cred->fsgid;
304 } else {
305 /*
306 * Using the euid would make more sense here, but something
307 * in userland might rely on the old behavior, and this
308 * shouldn't be a security problem since
309 * PTRACE_MODE_REALCREDS implies that the caller explicitly
310 * used a syscall that requests access to another process
311 * (and not a filesystem syscall to procfs).
312 */
313 caller_uid = cred->uid;
314 caller_gid = cred->gid;
315 }
David Howellsc69e8d92008-11-14 10:39:19 +1100316 tcred = __task_cred(task);
Jann Horncaaee622016-01-20 15:00:04 -0800317 if (uid_eq(caller_uid, tcred->euid) &&
318 uid_eq(caller_uid, tcred->suid) &&
319 uid_eq(caller_uid, tcred->uid) &&
320 gid_eq(caller_gid, tcred->egid) &&
321 gid_eq(caller_gid, tcred->sgid) &&
322 gid_eq(caller_gid, tcred->gid))
Serge E. Hallyn8409cca2011-03-23 16:43:20 -0700323 goto ok;
Mickaël Salaüncf237052020-10-30 13:38:48 +0100324 if (ptrace_has_cap(tcred->user_ns, mode))
Serge E. Hallyn8409cca2011-03-23 16:43:20 -0700325 goto ok;
326 rcu_read_unlock();
327 return -EPERM;
328ok:
David Howellsc69e8d92008-11-14 10:39:19 +1100329 rcu_read_unlock();
Jann Hornf6581f5b2019-05-29 13:31:57 +0200330 /*
331 * If a task drops privileges and becomes nondumpable (through a syscall
332 * like setresuid()) while we are trying to access it, we must ensure
333 * that the dumpability is read after the credentials; otherwise,
334 * we may be able to attach to a task that we shouldn't be able to
335 * attach to (as if the task had dropped privileges without becoming
336 * nondumpable).
337 * Pairs with a write barrier in commit_creds().
338 */
339 smp_rmb();
Eric W. Biedermanbfedb582016-10-13 21:23:16 -0500340 mm = task->mm;
341 if (mm &&
342 ((get_dumpable(mm) != SUID_DUMP_USER) &&
Mickaël Salaüncf237052020-10-30 13:38:48 +0100343 !ptrace_has_cap(mm->user_ns, mode)))
Eric W. Biedermanbfedb582016-10-13 21:23:16 -0500344 return -EPERM;
Miklos Szerediab8d11b2005-09-06 15:18:24 -0700345
Ingo Molnar9e488582009-05-07 19:26:19 +1000346 return security_ptrace_access_check(task, mode);
Miklos Szerediab8d11b2005-09-06 15:18:24 -0700347}
348
Stephen Smalley006ebb42008-05-19 08:32:49 -0400349bool ptrace_may_access(struct task_struct *task, unsigned int mode)
Miklos Szerediab8d11b2005-09-06 15:18:24 -0700350{
351 int err;
352 task_lock(task);
Stephen Smalley006ebb42008-05-19 08:32:49 -0400353 err = __ptrace_may_access(task, mode);
Miklos Szerediab8d11b2005-09-06 15:18:24 -0700354 task_unlock(task);
Roland McGrath3a709702009-04-07 23:21:06 -0700355 return !err;
Miklos Szerediab8d11b2005-09-06 15:18:24 -0700356}
357
Jann Hornee1fee92022-03-19 02:08:37 +0100358static int check_ptrace_options(unsigned long data)
359{
360 if (data & ~(unsigned long)PTRACE_O_MASK)
361 return -EINVAL;
362
363 if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) {
364 if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) ||
365 !IS_ENABLED(CONFIG_SECCOMP))
366 return -EINVAL;
367
368 if (!capable(CAP_SYS_ADMIN))
369 return -EPERM;
370
371 if (seccomp_mode(&current->seccomp) != SECCOMP_MODE_DISABLED ||
372 current->ptrace & PT_SUSPEND_SECCOMP)
373 return -EPERM;
374 }
375 return 0;
376}
377
Peter Zijlstra5431fdd2023-09-17 13:24:21 +0200378static inline void ptrace_set_stopped(struct task_struct *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379{
Peter Zijlstra5431fdd2023-09-17 13:24:21 +0200380 guard(spinlock)(&task->sighand->siglock);
Tejun Heod79fdd62011-03-23 10:37:00 +0100381
382 /*
Tejun Heo73ddff22011-06-14 11:20:14 +0200383 * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
Tejun Heod79fdd62011-03-23 10:37:00 +0100384 * TRAPPING, and kick it so that it transits to TRACED. TRAPPING
385 * will be cleared if the child completes the transition or any
386 * event which clears the group stop states happens. We'll wait
387 * for the transition to complete before returning from this
388 * function.
389 *
390 * This hides STOPPED -> RUNNING -> TRACED transition from the
391 * attaching thread but a different thread in the same group can
392 * still observe the transient RUNNING state. IOW, if another
393 * thread's WNOHANG wait(2) on the stopped tracee races against
394 * ATTACH, the wait(2) may fail due to the transient RUNNING.
395 *
396 * The following task_is_stopped() test is safe as both transitions
397 * in and out of STOPPED are protected by siglock.
398 */
Tejun Heo7dd3db52011-06-02 11:14:00 +0200399 if (task_is_stopped(task) &&
Peter Zijlstra31cae1e2022-05-03 15:57:47 -0500400 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) {
401 task->jobctl &= ~JOBCTL_STOPPED;
Oleg Nesterov910ffdb12013-01-21 20:47:41 +0100402 signal_wake_up_state(task, __TASK_STOPPED);
Peter Zijlstra31cae1e2022-05-03 15:57:47 -0500403 }
Peter Zijlstra5431fdd2023-09-17 13:24:21 +0200404}
Tejun Heod79fdd62011-03-23 10:37:00 +0100405
Peter Zijlstra5431fdd2023-09-17 13:24:21 +0200406static int ptrace_attach(struct task_struct *task, long request,
407 unsigned long addr,
408 unsigned long flags)
409{
410 bool seize = (request == PTRACE_SEIZE);
411 int retval;
Tejun Heod79fdd62011-03-23 10:37:00 +0100412
Peter Zijlstra5431fdd2023-09-17 13:24:21 +0200413 if (seize) {
414 if (addr != 0)
415 return -EIO;
Oleg Nesterov7c3b00e2016-01-20 14:59:55 -0800416 /*
Peter Zijlstra5431fdd2023-09-17 13:24:21 +0200417 * This duplicates the check in check_ptrace_options() because
418 * ptrace_attach() and ptrace_setoptions() have historically
419 * used different error codes for unknown ptrace options.
Oleg Nesterov7c3b00e2016-01-20 14:59:55 -0800420 */
Peter Zijlstra5431fdd2023-09-17 13:24:21 +0200421 if (flags & ~(unsigned long)PTRACE_O_MASK)
422 return -EIO;
423
424 retval = check_ptrace_options(flags);
425 if (retval)
426 return retval;
427 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
428 } else {
429 flags = PT_PTRACED;
Vladimir Zapolskiyf701e5b2011-07-15 20:45:18 +0300430 }
431
Peter Zijlstra5431fdd2023-09-17 13:24:21 +0200432 audit_ptrace(task);
433
434 if (unlikely(task->flags & PF_KTHREAD))
435 return -EPERM;
436 if (same_thread_group(task, current))
437 return -EPERM;
438
439 /*
440 * Protect exec's credential calculations against our interference;
441 * SUID, SGID and LSM creds get determined differently
442 * under ptrace.
443 */
444 scoped_cond_guard (mutex_intr, return -ERESTARTNOINTR,
445 &task->signal->cred_guard_mutex) {
446
447 scoped_guard (task_lock, task) {
448 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
449 if (retval)
450 return retval;
451 }
452
453 scoped_guard (write_lock_irq, &tasklist_lock) {
454 if (unlikely(task->exit_state))
455 return -EPERM;
456 if (task->ptrace)
457 return -EPERM;
458
459 task->ptrace = flags;
460
461 ptrace_link(task, current);
462
463 /* SEIZE doesn't trap tracee on attach */
464 if (!seize)
465 send_sig_info(SIGSTOP, SEND_SIG_PRIV, task);
466
467 ptrace_set_stopped(task);
468 }
469 }
470
471 /*
472 * We do not bother to change retval or clear JOBCTL_TRAPPING
473 * if wait_on_bit() was interrupted by SIGKILL. The tracer will
474 * not return to user-mode, it will exit and clear this bit in
475 * __ptrace_unlink() if it wasn't already cleared by the tracee;
476 * and until then nobody can ptrace this task.
477 */
478 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE);
479 proc_ptrace_connector(task, PTRACE_ATTACH);
480
481 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482}
483
Oleg Nesterovf2f0b002009-06-17 16:27:32 -0700484/**
485 * ptrace_traceme -- helper for PTRACE_TRACEME
486 *
487 * Performs checks and sets PT_PTRACED.
488 * Should be used by all ptrace implementations for PTRACE_TRACEME.
489 */
Linus Torvaldse3e89cc2011-03-04 09:23:30 -0800490static int ptrace_traceme(void)
Oleg Nesterovf2f0b002009-06-17 16:27:32 -0700491{
492 int ret = -EPERM;
493
Oleg Nesterov4b105cb2009-06-17 16:27:33 -0700494 write_lock_irq(&tasklist_lock);
495 /* Are we already being traced? */
Oleg Nesterovf2f0b002009-06-17 16:27:32 -0700496 if (!current->ptrace) {
Oleg Nesterovf2f0b002009-06-17 16:27:32 -0700497 ret = security_ptrace_traceme(current->parent);
Oleg Nesterovf2f0b002009-06-17 16:27:32 -0700498 /*
499 * Check PF_EXITING to ensure ->real_parent has not passed
500 * exit_ptrace(). Otherwise we don't report the error but
501 * pretend ->real_parent untraces us right after return.
502 */
503 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
504 current->ptrace = PT_PTRACED;
Eric W. Biedermanc70d9d82017-05-22 15:40:12 -0500505 ptrace_link(current, current->real_parent);
Oleg Nesterovf2f0b002009-06-17 16:27:32 -0700506 }
Oleg Nesterovf2f0b002009-06-17 16:27:32 -0700507 }
Oleg Nesterov4b105cb2009-06-17 16:27:33 -0700508 write_unlock_irq(&tasklist_lock);
509
Oleg Nesterovf2f0b002009-06-17 16:27:32 -0700510 return ret;
511}
512
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700513/*
514 * Called with irqs disabled, returns true if childs should reap themselves.
515 */
516static int ignoring_children(struct sighand_struct *sigh)
517{
518 int ret;
519 spin_lock(&sigh->siglock);
520 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
521 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
522 spin_unlock(&sigh->siglock);
523 return ret;
524}
525
526/*
527 * Called with tasklist_lock held for writing.
528 * Unlink a traced task, and clean it up if it was a traced zombie.
529 * Return true if it needs to be reaped with release_task().
530 * (We can't call release_task() here because we already hold tasklist_lock.)
531 *
532 * If it's a zombie, our attachedness prevented normal parent notification
533 * or self-reaping. Do notification now if it would have happened earlier.
534 * If it should reap itself, return true.
535 *
Oleg Nesterova7f07652009-09-23 15:56:44 -0700536 * If it's our own child, there is no notification to do. But if our normal
537 * children self-reap, then this child was prevented by ptrace and we must
538 * reap it now, in that case we must also wake up sub-threads sleeping in
539 * do_wait().
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700540 */
541static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
542{
Oleg Nesterov9843a1e2011-06-22 23:08:53 +0200543 bool dead;
544
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700545 __ptrace_unlink(p);
546
Oleg Nesterov9843a1e2011-06-22 23:08:53 +0200547 if (p->exit_state != EXIT_ZOMBIE)
548 return false;
549
550 dead = !thread_group_leader(p);
551
552 if (!dead && thread_group_empty(p)) {
553 if (!same_thread_group(p->real_parent, tracer))
554 dead = do_notify_parent(p, p->exit_signal);
555 else if (ignoring_children(tracer->sighand)) {
556 __wake_up_parent(p, tracer);
Oleg Nesterov9843a1e2011-06-22 23:08:53 +0200557 dead = true;
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700558 }
559 }
Oleg Nesterov9843a1e2011-06-22 23:08:53 +0200560 /* Mark it as in the process of being reaped. */
561 if (dead)
562 p->exit_state = EXIT_DEAD;
563 return dead;
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700564}
565
Linus Torvaldse3e89cc2011-03-04 09:23:30 -0800566static int ptrace_detach(struct task_struct *child, unsigned int data)
Oleg Nesterov5ecfbae2006-02-15 22:50:10 +0300567{
568 if (!valid_signal(data))
569 return -EIO;
570
571 /* Architecture-specific hardware disable .. */
572 ptrace_disable(child);
573
Oleg Nesterov95c3eb72009-04-02 16:58:11 -0700574 write_lock_irq(&tasklist_lock);
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700575 /*
Oleg Nesterov64a40962015-04-16 12:47:32 -0700576 * We rely on ptrace_freeze_traced(). It can't be killed and
577 * untraced by another thread, it can't be a zombie.
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700578 */
Oleg Nesterov64a40962015-04-16 12:47:32 -0700579 WARN_ON(!child->ptrace || child->exit_state);
580 /*
581 * tasklist_lock avoids the race with wait_task_stopped(), see
582 * the comment in ptrace_resume().
583 */
584 child->exit_code = data;
585 __ptrace_detach(current, child);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 write_unlock_irq(&tasklist_lock);
587
Vladimir Zapolskiyf701e5b2011-07-15 20:45:18 +0300588 proc_ptrace_connector(child, PTRACE_DETACH);
Oleg Nesterov45761452009-04-02 16:58:14 -0700589
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 return 0;
591}
592
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700593/*
Oleg Nesterovc7e49c12010-08-10 18:03:07 -0700594 * Detach all tasks we were using ptrace on. Called with tasklist held
Oleg Nesterov7c8bd232014-12-10 15:45:33 -0800595 * for writing.
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700596 */
Oleg Nesterov7c8bd232014-12-10 15:45:33 -0800597void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700598{
599 struct task_struct *p, *n;
Oleg Nesterovc7e49c12010-08-10 18:03:07 -0700600
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700601 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
Oleg Nesterov992fb6e2012-12-17 16:03:07 -0800602 if (unlikely(p->ptrace & PT_EXITKILL))
Eric W. Biederman079b22d2018-09-03 10:32:52 +0200603 send_sig_info(SIGKILL, SEND_SIG_PRIV, p);
Oleg Nesterov992fb6e2012-12-17 16:03:07 -0800604
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700605 if (__ptrace_detach(tracer, p))
Oleg Nesterov7c8bd232014-12-10 15:45:33 -0800606 list_add(&p->ptrace_entry, dead);
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700607 }
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700608}
609
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
611{
612 int copied = 0;
613
614 while (len > 0) {
615 char buf[128];
616 int this_len, retval;
617
618 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
Eric W. Biederman84d77d32016-11-22 12:06:50 -0600619 retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE);
620
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 if (!retval) {
622 if (copied)
623 break;
624 return -EIO;
625 }
626 if (copy_to_user(dst, buf, retval))
627 return -EFAULT;
628 copied += retval;
629 src += retval;
630 dst += retval;
Roland McGrath3a709702009-04-07 23:21:06 -0700631 len -= retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 }
633 return copied;
634}
635
636int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
637{
638 int copied = 0;
639
640 while (len > 0) {
641 char buf[128];
642 int this_len, retval;
643
644 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
645 if (copy_from_user(buf, src, this_len))
646 return -EFAULT;
Eric W. Biederman84d77d32016-11-22 12:06:50 -0600647 retval = ptrace_access_vm(tsk, dst, buf, this_len,
Lorenzo Stoakesf307ab62016-10-13 01:20:20 +0100648 FOLL_FORCE | FOLL_WRITE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 if (!retval) {
650 if (copied)
651 break;
652 return -EIO;
653 }
654 copied += retval;
655 src += retval;
656 dst += retval;
Roland McGrath3a709702009-04-07 23:21:06 -0700657 len -= retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 }
659 return copied;
660}
661
Namhyung Kim4abf9862010-10-27 15:33:45 -0700662static int ptrace_setoptions(struct task_struct *child, unsigned long data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663{
Denys Vlasenko86b6c1f2012-03-23 15:02:41 -0700664 unsigned flags;
Jann Hornee1fee92022-03-19 02:08:37 +0100665 int ret;
Denys Vlasenko86b6c1f2012-03-23 15:02:41 -0700666
Jann Hornee1fee92022-03-19 02:08:37 +0100667 ret = check_ptrace_options(data);
668 if (ret)
669 return ret;
Tycho Andersen13c4a902015-06-13 09:02:48 -0600670
Denys Vlasenko86b6c1f2012-03-23 15:02:41 -0700671 /* Avoid intermediate state when all opts are cleared */
672 flags = child->ptrace;
673 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
674 flags |= (data << PT_OPT_FLAG_SHIFT);
675 child->ptrace = flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676
Denys Vlasenko8c5cf9e2012-03-23 15:02:40 -0700677 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678}
679
Eric W. Biedermanae7795b2018-09-25 11:27:20 +0200680static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681{
Oleg Nesterove4961252009-06-17 16:27:36 -0700682 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 int error = -ESRCH;
684
Oleg Nesterove4961252009-06-17 16:27:36 -0700685 if (lock_task_sighand(child, &flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 error = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 if (likely(child->last_siginfo != NULL)) {
Eric W. Biederman0752d7bf2017-07-24 15:08:16 -0500688 copy_siginfo(info, child->last_siginfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 error = 0;
690 }
Oleg Nesterove4961252009-06-17 16:27:36 -0700691 unlock_task_sighand(child, &flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 return error;
694}
695
Eric W. Biedermanae7795b2018-09-25 11:27:20 +0200696static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697{
Oleg Nesterove4961252009-06-17 16:27:36 -0700698 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 int error = -ESRCH;
700
Oleg Nesterove4961252009-06-17 16:27:36 -0700701 if (lock_task_sighand(child, &flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 error = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 if (likely(child->last_siginfo != NULL)) {
Eric W. Biederman0752d7bf2017-07-24 15:08:16 -0500704 copy_siginfo(child->last_siginfo, info);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 error = 0;
706 }
Oleg Nesterove4961252009-06-17 16:27:36 -0700707 unlock_task_sighand(child, &flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 return error;
710}
711
Andrey Vagin84c751b2013-04-30 15:27:59 -0700712static int ptrace_peek_siginfo(struct task_struct *child,
713 unsigned long addr,
714 unsigned long data)
715{
716 struct ptrace_peeksiginfo_args arg;
717 struct sigpending *pending;
718 struct sigqueue *q;
719 int ret, i;
720
721 ret = copy_from_user(&arg, (void __user *) addr,
722 sizeof(struct ptrace_peeksiginfo_args));
723 if (ret)
724 return -EFAULT;
725
726 if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
727 return -EINVAL; /* unknown flags */
728
729 if (arg.nr < 0)
730 return -EINVAL;
731
Eric W. Biedermanf6e2aa92019-05-28 18:46:37 -0500732 /* Ensure arg.off fits in an unsigned long */
733 if (arg.off > ULONG_MAX)
734 return 0;
735
Andrey Vagin84c751b2013-04-30 15:27:59 -0700736 if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
737 pending = &child->signal->shared_pending;
738 else
739 pending = &child->pending;
740
741 for (i = 0; i < arg.nr; ) {
Eric W. Biedermanae7795b2018-09-25 11:27:20 +0200742 kernel_siginfo_t info;
Eric W. Biedermanf6e2aa92019-05-28 18:46:37 -0500743 unsigned long off = arg.off + i;
744 bool found = false;
Andrey Vagin84c751b2013-04-30 15:27:59 -0700745
746 spin_lock_irq(&child->sighand->siglock);
747 list_for_each_entry(q, &pending->list, list) {
748 if (!off--) {
Eric W. Biedermanf6e2aa92019-05-28 18:46:37 -0500749 found = true;
Andrey Vagin84c751b2013-04-30 15:27:59 -0700750 copy_siginfo(&info, &q->info);
751 break;
752 }
753 }
754 spin_unlock_irq(&child->sighand->siglock);
755
Eric W. Biedermanf6e2aa92019-05-28 18:46:37 -0500756 if (!found) /* beyond the end of the list */
Andrey Vagin84c751b2013-04-30 15:27:59 -0700757 break;
758
759#ifdef CONFIG_COMPAT
Andy Lutomirski5c465212016-03-22 14:24:55 -0700760 if (unlikely(in_compat_syscall())) {
Andrey Vagin84c751b2013-04-30 15:27:59 -0700761 compat_siginfo_t __user *uinfo = compat_ptr(data);
762
Eric W. Biedermancc731522017-07-16 22:36:59 -0500763 if (copy_siginfo_to_user32(uinfo, &info)) {
Mathieu Desnoyers706b23b2013-06-28 09:49:46 -0400764 ret = -EFAULT;
765 break;
766 }
767
Andrey Vagin84c751b2013-04-30 15:27:59 -0700768 } else
769#endif
770 {
771 siginfo_t __user *uinfo = (siginfo_t __user *) data;
772
Eric W. Biedermancc731522017-07-16 22:36:59 -0500773 if (copy_siginfo_to_user(uinfo, &info)) {
Mathieu Desnoyers706b23b2013-06-28 09:49:46 -0400774 ret = -EFAULT;
775 break;
776 }
Andrey Vagin84c751b2013-04-30 15:27:59 -0700777 }
778
779 data += sizeof(siginfo_t);
780 i++;
781
782 if (signal_pending(current))
783 break;
784
785 cond_resched();
786 }
787
788 if (i > 0)
789 return i;
790
791 return ret;
792}
Roland McGrath36df29d2008-01-30 13:30:51 +0100793
Piotr Figiel90f093f2021-02-26 14:51:56 +0100794#ifdef CONFIG_RSEQ
795static long ptrace_get_rseq_configuration(struct task_struct *task,
796 unsigned long size, void __user *data)
797{
798 struct ptrace_rseq_configuration conf = {
799 .rseq_abi_pointer = (u64)(uintptr_t)task->rseq,
Mathieu Desnoyersee3e3ac2022-11-22 15:39:05 -0500800 .rseq_abi_size = task->rseq_len,
Piotr Figiel90f093f2021-02-26 14:51:56 +0100801 .signature = task->rseq_sig,
802 .flags = 0,
803 };
804
805 size = min_t(unsigned long, size, sizeof(conf));
806 if (copy_to_user(data, &conf, size))
807 return -EFAULT;
808 return sizeof(conf);
809}
810#endif
811
Roland McGrath36df29d2008-01-30 13:30:51 +0100812#define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
Roland McGrath36df29d2008-01-30 13:30:51 +0100813
Roland McGrath5b88abb2008-01-30 13:30:53 +0100814#ifdef PTRACE_SINGLEBLOCK
815#define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
816#else
817#define is_singleblock(request) 0
818#endif
819
Roland McGrath36df29d2008-01-30 13:30:51 +0100820#ifdef PTRACE_SYSEMU
821#define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
822#else
823#define is_sysemu_singlestep(request) 0
824#endif
825
Namhyung Kim4abf9862010-10-27 15:33:45 -0700826static int ptrace_resume(struct task_struct *child, long request,
827 unsigned long data)
Roland McGrath36df29d2008-01-30 13:30:51 +0100828{
829 if (!valid_signal(data))
830 return -EIO;
831
832 if (request == PTRACE_SYSCALL)
Gabriel Krisman Bertazi64c19ba2020-11-16 12:42:02 -0500833 set_task_syscall_work(child, SYSCALL_TRACE);
Roland McGrath36df29d2008-01-30 13:30:51 +0100834 else
Gabriel Krisman Bertazi64c19ba2020-11-16 12:42:02 -0500835 clear_task_syscall_work(child, SYSCALL_TRACE);
Roland McGrath36df29d2008-01-30 13:30:51 +0100836
Gabriel Krisman Bertazi64eb35f2020-11-16 12:42:03 -0500837#if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU)
Roland McGrath36df29d2008-01-30 13:30:51 +0100838 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
Gabriel Krisman Bertazi64eb35f2020-11-16 12:42:03 -0500839 set_task_syscall_work(child, SYSCALL_EMU);
Roland McGrath36df29d2008-01-30 13:30:51 +0100840 else
Gabriel Krisman Bertazi64eb35f2020-11-16 12:42:03 -0500841 clear_task_syscall_work(child, SYSCALL_EMU);
Roland McGrath36df29d2008-01-30 13:30:51 +0100842#endif
843
Roland McGrath5b88abb2008-01-30 13:30:53 +0100844 if (is_singleblock(request)) {
845 if (unlikely(!arch_has_block_step()))
846 return -EIO;
847 user_enable_block_step(child);
848 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
Roland McGrath36df29d2008-01-30 13:30:51 +0100849 if (unlikely(!arch_has_single_step()))
850 return -EIO;
851 user_enable_single_step(child);
Roland McGrath3a709702009-04-07 23:21:06 -0700852 } else {
Roland McGrath36df29d2008-01-30 13:30:51 +0100853 user_disable_single_step(child);
Roland McGrath3a709702009-04-07 23:21:06 -0700854 }
Roland McGrath36df29d2008-01-30 13:30:51 +0100855
Oleg Nesterovb72c1862015-04-16 12:47:29 -0700856 /*
857 * Change ->exit_code and ->state under siglock to avoid the race
858 * with wait_task_stopped() in between; a non-zero ->exit_code will
859 * wrongly look like another report from tracee.
860 *
861 * Note that we need siglock even if ->exit_code == data and/or this
862 * status was not reported yet, the new status must not be cleared by
863 * wait_task_stopped() after resume.
Oleg Nesterovb72c1862015-04-16 12:47:29 -0700864 */
Eric W. Biederman5b4197c2022-04-29 10:50:17 -0500865 spin_lock_irq(&child->sighand->siglock);
Roland McGrath36df29d2008-01-30 13:30:51 +0100866 child->exit_code = data;
Peter Zijlstra31cae1e2022-05-03 15:57:47 -0500867 child->jobctl &= ~JOBCTL_TRACED;
Oleg Nesterov0666fb52011-05-25 19:20:21 +0200868 wake_up_state(child, __TASK_TRACED);
Eric W. Biederman5b4197c2022-04-29 10:50:17 -0500869 spin_unlock_irq(&child->sighand->siglock);
Roland McGrath36df29d2008-01-30 13:30:51 +0100870
871 return 0;
872}
873
Suresh Siddha2225a122010-02-11 11:51:00 -0800874#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
875
876static const struct user_regset *
877find_regset(const struct user_regset_view *view, unsigned int type)
878{
879 const struct user_regset *regset;
880 int n;
881
882 for (n = 0; n < view->n; ++n) {
883 regset = view->regsets + n;
884 if (regset->core_note_type == type)
885 return regset;
886 }
887
888 return NULL;
889}
890
891static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
892 struct iovec *kiov)
893{
894 const struct user_regset_view *view = task_user_regset_view(task);
895 const struct user_regset *regset = find_regset(view, type);
896 int regset_no;
897
898 if (!regset || (kiov->iov_len % regset->size) != 0)
Suresh Siddhac6a0dd72010-02-22 14:51:32 -0800899 return -EINVAL;
Suresh Siddha2225a122010-02-11 11:51:00 -0800900
901 regset_no = regset - view->regsets;
902 kiov->iov_len = min(kiov->iov_len,
903 (__kernel_size_t) (regset->n * regset->size));
904
905 if (req == PTRACE_GETREGSET)
906 return copy_regset_to_user(task, view, regset_no, 0,
907 kiov->iov_len, kiov->iov_base);
908 else
909 return copy_regset_from_user(task, view, regset_no, 0,
910 kiov->iov_len, kiov->iov_base);
911}
912
Josh Stonee8440c142013-01-13 19:03:34 +0100913/*
914 * This is declared in linux/regset.h and defined in machine-dependent
915 * code. We put the export here, near the primary machine-neutral use,
916 * to ensure no machine forgets it.
917 */
918EXPORT_SYMBOL_GPL(task_user_regset_view);
Elvira Khabirova201766a2019-07-16 16:29:42 -0700919
920static unsigned long
921ptrace_get_syscall_info_entry(struct task_struct *child, struct pt_regs *regs,
922 struct ptrace_syscall_info *info)
923{
924 unsigned long args[ARRAY_SIZE(info->entry.args)];
925 int i;
926
927 info->op = PTRACE_SYSCALL_INFO_ENTRY;
928 info->entry.nr = syscall_get_nr(child, regs);
929 syscall_get_arguments(child, regs, args);
930 for (i = 0; i < ARRAY_SIZE(args); i++)
931 info->entry.args[i] = args[i];
932
933 /* args is the last field in struct ptrace_syscall_info.entry */
934 return offsetofend(struct ptrace_syscall_info, entry.args);
935}
936
937static unsigned long
938ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs,
939 struct ptrace_syscall_info *info)
940{
941 /*
942 * As struct ptrace_syscall_info.entry is currently a subset
943 * of struct ptrace_syscall_info.seccomp, it makes sense to
944 * initialize that subset using ptrace_get_syscall_info_entry().
945 * This can be reconsidered in the future if these structures
946 * diverge significantly enough.
947 */
948 ptrace_get_syscall_info_entry(child, regs, info);
949 info->op = PTRACE_SYSCALL_INFO_SECCOMP;
950 info->seccomp.ret_data = child->ptrace_message;
951
952 /* ret_data is the last field in struct ptrace_syscall_info.seccomp */
953 return offsetofend(struct ptrace_syscall_info, seccomp.ret_data);
954}
955
956static unsigned long
957ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs,
958 struct ptrace_syscall_info *info)
959{
960 info->op = PTRACE_SYSCALL_INFO_EXIT;
961 info->exit.rval = syscall_get_error(child, regs);
962 info->exit.is_error = !!info->exit.rval;
963 if (!info->exit.is_error)
964 info->exit.rval = syscall_get_return_value(child, regs);
965
966 /* is_error is the last field in struct ptrace_syscall_info.exit */
967 return offsetofend(struct ptrace_syscall_info, exit.is_error);
968}
969
970static int
971ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size,
972 void __user *datavp)
973{
974 struct pt_regs *regs = task_pt_regs(child);
975 struct ptrace_syscall_info info = {
976 .op = PTRACE_SYSCALL_INFO_NONE,
977 .arch = syscall_get_arch(child),
978 .instruction_pointer = instruction_pointer(regs),
979 .stack_pointer = user_stack_pointer(regs),
980 };
981 unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry);
982 unsigned long write_size;
983
984 /*
985 * This does not need lock_task_sighand() to access
986 * child->last_siginfo because ptrace_freeze_traced()
987 * called earlier by ptrace_check_attach() ensures that
988 * the tracee cannot go away and clear its last_siginfo.
989 */
990 switch (child->last_siginfo ? child->last_siginfo->si_code : 0) {
991 case SIGTRAP | 0x80:
992 switch (child->ptrace_message) {
993 case PTRACE_EVENTMSG_SYSCALL_ENTRY:
994 actual_size = ptrace_get_syscall_info_entry(child, regs,
995 &info);
996 break;
997 case PTRACE_EVENTMSG_SYSCALL_EXIT:
998 actual_size = ptrace_get_syscall_info_exit(child, regs,
999 &info);
1000 break;
1001 }
1002 break;
1003 case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8):
1004 actual_size = ptrace_get_syscall_info_seccomp(child, regs,
1005 &info);
1006 break;
1007 }
1008
1009 write_size = min(actual_size, user_size);
1010 return copy_to_user(datavp, &info, write_size) ? -EFAULT : actual_size;
1011}
1012#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
Suresh Siddha2225a122010-02-11 11:51:00 -08001013
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014int ptrace_request(struct task_struct *child, long request,
Namhyung Kim4abf9862010-10-27 15:33:45 -07001015 unsigned long addr, unsigned long data)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016{
Tejun Heofca26f22011-06-14 11:20:16 +02001017 bool seized = child->ptrace & PT_SEIZED;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 int ret = -EIO;
Eric W. Biedermanae7795b2018-09-25 11:27:20 +02001019 kernel_siginfo_t siginfo, *si;
Namhyung Kim9fed81d2010-10-27 15:33:46 -07001020 void __user *datavp = (void __user *) data;
1021 unsigned long __user *datalp = datavp;
Tejun Heofca26f22011-06-14 11:20:16 +02001022 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023
1024 switch (request) {
Roland McGrath16c3e382008-01-30 13:31:47 +01001025 case PTRACE_PEEKTEXT:
1026 case PTRACE_PEEKDATA:
1027 return generic_ptrace_peekdata(child, addr, data);
1028 case PTRACE_POKETEXT:
1029 case PTRACE_POKEDATA:
1030 return generic_ptrace_pokedata(child, addr, data);
1031
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032#ifdef PTRACE_OLDSETOPTIONS
1033 case PTRACE_OLDSETOPTIONS:
1034#endif
1035 case PTRACE_SETOPTIONS:
1036 ret = ptrace_setoptions(child, data);
1037 break;
1038 case PTRACE_GETEVENTMSG:
Namhyung Kim9fed81d2010-10-27 15:33:46 -07001039 ret = put_user(child->ptrace_message, datalp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040 break;
Roland McGrathe16b2782008-04-20 13:10:12 -07001041
Andrey Vagin84c751b2013-04-30 15:27:59 -07001042 case PTRACE_PEEKSIGINFO:
1043 ret = ptrace_peek_siginfo(child, addr, data);
1044 break;
1045
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046 case PTRACE_GETSIGINFO:
Roland McGrathe16b2782008-04-20 13:10:12 -07001047 ret = ptrace_getsiginfo(child, &siginfo);
1048 if (!ret)
Namhyung Kim9fed81d2010-10-27 15:33:46 -07001049 ret = copy_siginfo_to_user(datavp, &siginfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050 break;
Roland McGrathe16b2782008-04-20 13:10:12 -07001051
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052 case PTRACE_SETSIGINFO:
Eric W. Biederman4cd2e0e2018-04-18 17:30:19 -05001053 ret = copy_siginfo_from_user(&siginfo, datavp);
1054 if (!ret)
Roland McGrathe16b2782008-04-20 13:10:12 -07001055 ret = ptrace_setsiginfo(child, &siginfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056 break;
Roland McGrathe16b2782008-04-20 13:10:12 -07001057
Andrei Vaginfcfc2aa02019-03-28 20:44:13 -07001058 case PTRACE_GETSIGMASK: {
1059 sigset_t *mask;
1060
Andrey Vagin29000ca2013-07-03 15:08:12 -07001061 if (addr != sizeof(sigset_t)) {
1062 ret = -EINVAL;
1063 break;
1064 }
1065
Andrei Vaginfcfc2aa02019-03-28 20:44:13 -07001066 if (test_tsk_restore_sigmask(child))
1067 mask = &child->saved_sigmask;
1068 else
1069 mask = &child->blocked;
1070
1071 if (copy_to_user(datavp, mask, sizeof(sigset_t)))
Andrey Vagin29000ca2013-07-03 15:08:12 -07001072 ret = -EFAULT;
1073 else
1074 ret = 0;
1075
1076 break;
Andrei Vaginfcfc2aa02019-03-28 20:44:13 -07001077 }
Andrey Vagin29000ca2013-07-03 15:08:12 -07001078
1079 case PTRACE_SETSIGMASK: {
1080 sigset_t new_set;
1081
1082 if (addr != sizeof(sigset_t)) {
1083 ret = -EINVAL;
1084 break;
1085 }
1086
1087 if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
1088 ret = -EFAULT;
1089 break;
1090 }
1091
1092 sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
1093
1094 /*
1095 * Every thread does recalc_sigpending() after resume, so
1096 * retarget_shared_pending() and recalc_sigpending() are not
1097 * called here.
1098 */
1099 spin_lock_irq(&child->sighand->siglock);
1100 child->blocked = new_set;
1101 spin_unlock_irq(&child->sighand->siglock);
1102
Andrei Vaginfcfc2aa02019-03-28 20:44:13 -07001103 clear_tsk_restore_sigmask(child);
1104
Andrey Vagin29000ca2013-07-03 15:08:12 -07001105 ret = 0;
1106 break;
1107 }
1108
Tejun Heofca26f22011-06-14 11:20:16 +02001109 case PTRACE_INTERRUPT:
1110 /*
1111 * Stop tracee without any side-effect on signal or job
1112 * control. At least one trap is guaranteed to happen
1113 * after this request. If @child is already trapped, the
1114 * current trap is not disturbed and another trap will
1115 * happen after the current trap is ended with PTRACE_CONT.
1116 *
1117 * The actual trap might not be PTRACE_EVENT_STOP trap but
1118 * the pending condition is cleared regardless.
1119 */
1120 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1121 break;
1122
Tejun Heo544b2c92011-06-14 11:20:18 +02001123 /*
1124 * INTERRUPT doesn't disturb existing trap sans one
1125 * exception. If ptracer issued LISTEN for the current
1126 * STOP, this INTERRUPT should clear LISTEN and re-trap
1127 * tracee into STOP.
1128 */
Tejun Heofca26f22011-06-14 11:20:16 +02001129 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
Oleg Nesterov910ffdb12013-01-21 20:47:41 +01001130 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
Tejun Heo544b2c92011-06-14 11:20:18 +02001131
1132 unlock_task_sighand(child, &flags);
1133 ret = 0;
1134 break;
1135
1136 case PTRACE_LISTEN:
1137 /*
1138 * Listen for events. Tracee must be in STOP. It's not
1139 * resumed per-se but is not considered to be in TRACED by
1140 * wait(2) or ptrace(2). If an async event (e.g. group
1141 * stop state change) happens, tracee will enter STOP trap
1142 * again. Alternatively, ptracer can issue INTERRUPT to
1143 * finish listening and re-trap tracee into STOP.
1144 */
1145 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1146 break;
1147
1148 si = child->last_siginfo;
Oleg Nesterovf9d81f62011-09-25 19:46:22 +02001149 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
1150 child->jobctl |= JOBCTL_LISTENING;
1151 /*
1152 * If NOTIFY is set, it means event happened between
1153 * start of this trap and now. Trigger re-trap.
1154 */
1155 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
Oleg Nesterov910ffdb12013-01-21 20:47:41 +01001156 ptrace_signal_wake_up(child, true);
Oleg Nesterovf9d81f62011-09-25 19:46:22 +02001157 ret = 0;
1158 }
Tejun Heofca26f22011-06-14 11:20:16 +02001159 unlock_task_sighand(child, &flags);
Tejun Heofca26f22011-06-14 11:20:16 +02001160 break;
1161
Alexey Dobriyan1bcf5482007-10-16 01:23:45 -07001162 case PTRACE_DETACH: /* detach a process that was attached. */
1163 ret = ptrace_detach(child, data);
1164 break;
Roland McGrath36df29d2008-01-30 13:30:51 +01001165
Mike Frysinger9c1a1252010-05-26 14:42:52 -07001166#ifdef CONFIG_BINFMT_ELF_FDPIC
1167 case PTRACE_GETFDPIC: {
Oleg Nesterove0129ef2010-05-26 14:42:53 -07001168 struct mm_struct *mm = get_task_mm(child);
Mike Frysinger9c1a1252010-05-26 14:42:52 -07001169 unsigned long tmp = 0;
1170
Oleg Nesterove0129ef2010-05-26 14:42:53 -07001171 ret = -ESRCH;
1172 if (!mm)
1173 break;
1174
Mike Frysinger9c1a1252010-05-26 14:42:52 -07001175 switch (addr) {
1176 case PTRACE_GETFDPIC_EXEC:
Oleg Nesterove0129ef2010-05-26 14:42:53 -07001177 tmp = mm->context.exec_fdpic_loadmap;
Mike Frysinger9c1a1252010-05-26 14:42:52 -07001178 break;
1179 case PTRACE_GETFDPIC_INTERP:
Oleg Nesterove0129ef2010-05-26 14:42:53 -07001180 tmp = mm->context.interp_fdpic_loadmap;
Mike Frysinger9c1a1252010-05-26 14:42:52 -07001181 break;
1182 default:
1183 break;
1184 }
Oleg Nesterove0129ef2010-05-26 14:42:53 -07001185 mmput(mm);
Mike Frysinger9c1a1252010-05-26 14:42:52 -07001186
Namhyung Kim9fed81d2010-10-27 15:33:46 -07001187 ret = put_user(tmp, datalp);
Mike Frysinger9c1a1252010-05-26 14:42:52 -07001188 break;
1189 }
1190#endif
1191
Roland McGrath36df29d2008-01-30 13:30:51 +01001192 case PTRACE_SINGLESTEP:
Roland McGrath5b88abb2008-01-30 13:30:53 +01001193#ifdef PTRACE_SINGLEBLOCK
1194 case PTRACE_SINGLEBLOCK:
1195#endif
Roland McGrath36df29d2008-01-30 13:30:51 +01001196#ifdef PTRACE_SYSEMU
1197 case PTRACE_SYSEMU:
1198 case PTRACE_SYSEMU_SINGLESTEP:
1199#endif
1200 case PTRACE_SYSCALL:
1201 case PTRACE_CONT:
1202 return ptrace_resume(child, request, data);
1203
1204 case PTRACE_KILL:
Eric W. Biederman6a2d90b2022-04-29 09:23:55 -05001205 send_sig_info(SIGKILL, SEND_SIG_NOINFO, child);
1206 return 0;
Roland McGrath36df29d2008-01-30 13:30:51 +01001207
Suresh Siddha2225a122010-02-11 11:51:00 -08001208#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1209 case PTRACE_GETREGSET:
Andrey Vagin29000ca2013-07-03 15:08:12 -07001210 case PTRACE_SETREGSET: {
Suresh Siddha2225a122010-02-11 11:51:00 -08001211 struct iovec kiov;
Namhyung Kim9fed81d2010-10-27 15:33:46 -07001212 struct iovec __user *uiov = datavp;
Suresh Siddha2225a122010-02-11 11:51:00 -08001213
Linus Torvalds96d4f262019-01-03 18:57:57 -08001214 if (!access_ok(uiov, sizeof(*uiov)))
Suresh Siddha2225a122010-02-11 11:51:00 -08001215 return -EFAULT;
1216
1217 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
1218 __get_user(kiov.iov_len, &uiov->iov_len))
1219 return -EFAULT;
1220
1221 ret = ptrace_regset(child, request, addr, &kiov);
1222 if (!ret)
1223 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1224 break;
1225 }
Elvira Khabirova201766a2019-07-16 16:29:42 -07001226
1227 case PTRACE_GET_SYSCALL_INFO:
1228 ret = ptrace_get_syscall_info(child, addr, datavp);
1229 break;
Suresh Siddha2225a122010-02-11 11:51:00 -08001230#endif
Tycho Andersenf8e529ed2015-10-27 09:23:59 +09001231
1232 case PTRACE_SECCOMP_GET_FILTER:
1233 ret = seccomp_get_filter(child, addr, datavp);
1234 break;
1235
Tycho Andersen26500472017-10-11 09:39:21 -06001236 case PTRACE_SECCOMP_GET_METADATA:
1237 ret = seccomp_get_metadata(child, addr, datavp);
1238 break;
1239
Piotr Figiel90f093f2021-02-26 14:51:56 +01001240#ifdef CONFIG_RSEQ
1241 case PTRACE_GET_RSEQ_CONFIGURATION:
1242 ret = ptrace_get_rseq_configuration(child, addr, datavp);
1243 break;
1244#endif
1245
Gregory Price3f679872023-04-07 13:18:33 -04001246 case PTRACE_SET_SYSCALL_USER_DISPATCH_CONFIG:
1247 ret = syscall_user_dispatch_set_config(child, addr, datavp);
1248 break;
1249
1250 case PTRACE_GET_SYSCALL_USER_DISPATCH_CONFIG:
1251 ret = syscall_user_dispatch_get_config(child, addr, datavp);
1252 break;
1253
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254 default:
1255 break;
1256 }
1257
1258 return ret;
1259}
Christoph Hellwig481bed42005-11-07 00:59:47 -08001260
Namhyung Kim4abf9862010-10-27 15:33:45 -07001261SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1262 unsigned long, data)
Christoph Hellwig481bed42005-11-07 00:59:47 -08001263{
1264 struct task_struct *child;
1265 long ret;
1266
Christoph Hellwig6b9c7ed82006-01-08 01:02:33 -08001267 if (request == PTRACE_TRACEME) {
1268 ret = ptrace_traceme();
Christoph Hellwig481bed42005-11-07 00:59:47 -08001269 goto out;
Christoph Hellwig6b9c7ed82006-01-08 01:02:33 -08001270 }
1271
Mike Rapoport2ee08262018-02-06 15:40:17 -08001272 child = find_get_task_by_vpid(pid);
1273 if (!child) {
1274 ret = -ESRCH;
Christoph Hellwig6b9c7ed82006-01-08 01:02:33 -08001275 goto out;
1276 }
Christoph Hellwig481bed42005-11-07 00:59:47 -08001277
Tejun Heo3544d722011-06-14 11:20:15 +02001278 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
Denys Vlasenkoaa9147c2012-03-23 15:02:42 -07001279 ret = ptrace_attach(child, request, addr, data);
Christoph Hellwig005f18d2005-11-13 16:06:33 -08001280 goto out_put_task_struct;
Christoph Hellwig481bed42005-11-07 00:59:47 -08001281 }
1282
Tejun Heofca26f22011-06-14 11:20:16 +02001283 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1284 request == PTRACE_INTERRUPT);
Christoph Hellwig481bed42005-11-07 00:59:47 -08001285 if (ret < 0)
1286 goto out_put_task_struct;
1287
1288 ret = arch_ptrace(child, request, addr, data);
Oleg Nesterov9899d112013-01-21 20:48:00 +01001289 if (ret || request != PTRACE_DETACH)
1290 ptrace_unfreeze_traced(child);
Christoph Hellwig481bed42005-11-07 00:59:47 -08001291
1292 out_put_task_struct:
1293 put_task_struct(child);
1294 out:
Christoph Hellwig481bed42005-11-07 00:59:47 -08001295 return ret;
1296}
Alexey Dobriyan76647322007-07-17 04:03:43 -07001297
Namhyung Kim4abf9862010-10-27 15:33:45 -07001298int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1299 unsigned long data)
Alexey Dobriyan76647322007-07-17 04:03:43 -07001300{
1301 unsigned long tmp;
1302 int copied;
1303
Eric W. Biederman84d77d32016-11-22 12:06:50 -06001304 copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE);
Alexey Dobriyan76647322007-07-17 04:03:43 -07001305 if (copied != sizeof(tmp))
1306 return -EIO;
1307 return put_user(tmp, (unsigned long __user *)data);
1308}
Alexey Dobriyanf284ce72007-07-17 04:03:44 -07001309
Namhyung Kim4abf9862010-10-27 15:33:45 -07001310int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1311 unsigned long data)
Alexey Dobriyanf284ce72007-07-17 04:03:44 -07001312{
1313 int copied;
1314
Eric W. Biederman84d77d32016-11-22 12:06:50 -06001315 copied = ptrace_access_vm(tsk, addr, &data, sizeof(data),
Lorenzo Stoakesf307ab62016-10-13 01:20:20 +01001316 FOLL_FORCE | FOLL_WRITE);
Alexey Dobriyanf284ce72007-07-17 04:03:44 -07001317 return (copied == sizeof(data)) ? 0 : -EIO;
1318}
Roland McGrath032d82d2008-01-30 13:31:47 +01001319
Christoph Hellwig96b89362008-11-25 08:10:03 +01001320#if defined CONFIG_COMPAT
Roland McGrath032d82d2008-01-30 13:31:47 +01001321
1322int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1323 compat_ulong_t addr, compat_ulong_t data)
1324{
1325 compat_ulong_t __user *datap = compat_ptr(data);
1326 compat_ulong_t word;
Eric W. Biedermanae7795b2018-09-25 11:27:20 +02001327 kernel_siginfo_t siginfo;
Roland McGrath032d82d2008-01-30 13:31:47 +01001328 int ret;
1329
1330 switch (request) {
1331 case PTRACE_PEEKTEXT:
1332 case PTRACE_PEEKDATA:
Eric W. Biederman84d77d32016-11-22 12:06:50 -06001333 ret = ptrace_access_vm(child, addr, &word, sizeof(word),
Lorenzo Stoakesf307ab62016-10-13 01:20:20 +01001334 FOLL_FORCE);
Roland McGrath032d82d2008-01-30 13:31:47 +01001335 if (ret != sizeof(word))
1336 ret = -EIO;
1337 else
1338 ret = put_user(word, datap);
1339 break;
1340
1341 case PTRACE_POKETEXT:
1342 case PTRACE_POKEDATA:
Eric W. Biederman84d77d32016-11-22 12:06:50 -06001343 ret = ptrace_access_vm(child, addr, &data, sizeof(data),
Lorenzo Stoakesf307ab62016-10-13 01:20:20 +01001344 FOLL_FORCE | FOLL_WRITE);
Roland McGrath032d82d2008-01-30 13:31:47 +01001345 ret = (ret != sizeof(data) ? -EIO : 0);
1346 break;
1347
1348 case PTRACE_GETEVENTMSG:
1349 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1350 break;
1351
Roland McGrathe16b2782008-04-20 13:10:12 -07001352 case PTRACE_GETSIGINFO:
1353 ret = ptrace_getsiginfo(child, &siginfo);
1354 if (!ret)
1355 ret = copy_siginfo_to_user32(
1356 (struct compat_siginfo __user *) datap,
1357 &siginfo);
1358 break;
1359
1360 case PTRACE_SETSIGINFO:
Eric W. Biederman4cd2e0e2018-04-18 17:30:19 -05001361 ret = copy_siginfo_from_user32(
1362 &siginfo, (struct compat_siginfo __user *) datap);
1363 if (!ret)
Roland McGrathe16b2782008-04-20 13:10:12 -07001364 ret = ptrace_setsiginfo(child, &siginfo);
1365 break;
Suresh Siddha2225a122010-02-11 11:51:00 -08001366#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1367 case PTRACE_GETREGSET:
1368 case PTRACE_SETREGSET:
1369 {
1370 struct iovec kiov;
1371 struct compat_iovec __user *uiov =
1372 (struct compat_iovec __user *) datap;
1373 compat_uptr_t ptr;
1374 compat_size_t len;
1375
Linus Torvalds96d4f262019-01-03 18:57:57 -08001376 if (!access_ok(uiov, sizeof(*uiov)))
Suresh Siddha2225a122010-02-11 11:51:00 -08001377 return -EFAULT;
1378
1379 if (__get_user(ptr, &uiov->iov_base) ||
1380 __get_user(len, &uiov->iov_len))
1381 return -EFAULT;
1382
1383 kiov.iov_base = compat_ptr(ptr);
1384 kiov.iov_len = len;
1385
1386 ret = ptrace_regset(child, request, addr, &kiov);
1387 if (!ret)
1388 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1389 break;
1390 }
1391#endif
Roland McGrathe16b2782008-04-20 13:10:12 -07001392
Roland McGrath032d82d2008-01-30 13:31:47 +01001393 default:
1394 ret = ptrace_request(child, request, addr, data);
1395 }
1396
1397 return ret;
1398}
Roland McGrathc269f192008-01-30 13:31:48 +01001399
Heiko Carstens62a6fa972014-03-03 16:11:13 +01001400COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
1401 compat_long_t, addr, compat_long_t, data)
Roland McGrathc269f192008-01-30 13:31:48 +01001402{
1403 struct task_struct *child;
1404 long ret;
1405
Roland McGrathc269f192008-01-30 13:31:48 +01001406 if (request == PTRACE_TRACEME) {
1407 ret = ptrace_traceme();
1408 goto out;
1409 }
1410
Mike Rapoport2ee08262018-02-06 15:40:17 -08001411 child = find_get_task_by_vpid(pid);
1412 if (!child) {
1413 ret = -ESRCH;
Roland McGrathc269f192008-01-30 13:31:48 +01001414 goto out;
1415 }
1416
Tejun Heo3544d722011-06-14 11:20:15 +02001417 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
Denys Vlasenkoaa9147c2012-03-23 15:02:42 -07001418 ret = ptrace_attach(child, request, addr, data);
Roland McGrathc269f192008-01-30 13:31:48 +01001419 goto out_put_task_struct;
1420 }
1421
Tejun Heofca26f22011-06-14 11:20:16 +02001422 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1423 request == PTRACE_INTERRUPT);
Oleg Nesterov9899d112013-01-21 20:48:00 +01001424 if (!ret) {
Roland McGrathc269f192008-01-30 13:31:48 +01001425 ret = compat_arch_ptrace(child, request, addr, data);
Oleg Nesterov9899d112013-01-21 20:48:00 +01001426 if (ret || request != PTRACE_DETACH)
1427 ptrace_unfreeze_traced(child);
1428 }
Roland McGrathc269f192008-01-30 13:31:48 +01001429
1430 out_put_task_struct:
1431 put_task_struct(child);
1432 out:
Roland McGrathc269f192008-01-30 13:31:48 +01001433 return ret;
1434}
Christoph Hellwig96b89362008-11-25 08:10:03 +01001435#endif /* CONFIG_COMPAT */