Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/ptrace.c |
| 3 | * |
| 4 | * (C) Copyright 1999 Linus Torvalds |
| 5 | * |
| 6 | * Common interfaces for "ptrace()" which we do not want |
| 7 | * to continually duplicate across every architecture. |
| 8 | */ |
| 9 | |
Randy.Dunlap | c59ede7 | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 10 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/module.h> |
| 12 | #include <linux/sched.h> |
| 13 | #include <linux/errno.h> |
| 14 | #include <linux/mm.h> |
| 15 | #include <linux/highmem.h> |
| 16 | #include <linux/pagemap.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/ptrace.h> |
| 18 | #include <linux/security.h> |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 19 | #include <linux/signal.h> |
Al Viro | a5cb013 | 2007-03-20 13:58:35 -0400 | [diff] [blame] | 20 | #include <linux/audit.h> |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 21 | #include <linux/pid_namespace.h> |
Adrian Bunk | f17d30a | 2008-02-06 01:36:44 -0800 | [diff] [blame] | 22 | #include <linux/syscalls.h> |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 23 | #include <linux/uaccess.h> |
Suresh Siddha | 2225a12 | 2010-02-11 11:51:00 -0800 | [diff] [blame] | 24 | #include <linux/regset.h> |
Frederic Weisbecker | bf26c01 | 2011-04-07 16:53:20 +0200 | [diff] [blame] | 25 | #include <linux/hw_breakpoint.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | |
Markus Metzger | bf53de9 | 2008-12-19 15:10:24 +0100 | [diff] [blame] | 27 | |
| 28 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | * ptrace a task: make the debugger its new parent and |
| 30 | * move it to the ptrace list. |
| 31 | * |
| 32 | * Must be called with the tasklist lock write-held. |
| 33 | */ |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 34 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | { |
Roland McGrath | f470021 | 2008-03-24 18:36:23 -0700 | [diff] [blame] | 36 | BUG_ON(!list_empty(&child->ptrace_entry)); |
| 37 | list_add(&child->ptrace_entry, &new_parent->ptraced); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | child->parent = new_parent; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | } |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 40 | |
Tejun Heo | e3bd058 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 41 | /** |
| 42 | * __ptrace_unlink - unlink ptracee and restore its execution state |
| 43 | * @child: ptracee to be unlinked |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | * |
Tejun Heo | 0e9f0a4 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 45 | * Remove @child from the ptrace list, move it back to the original parent, |
| 46 | * and restore the execution state so that it conforms to the group stop |
| 47 | * state. |
| 48 | * |
| 49 | * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer |
| 50 | * exiting. For PTRACE_DETACH, unless the ptracee has been killed between |
| 51 | * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. |
| 52 | * If the ptracer is exiting, the ptracee can be in any state. |
| 53 | * |
| 54 | * After detach, the ptracee should be in a state which conforms to the |
| 55 | * group stop. If the group is stopped or in the process of stopping, the |
| 56 | * ptracee should be put into TASK_STOPPED; otherwise, it should be woken |
| 57 | * up from TASK_TRACED. |
| 58 | * |
| 59 | * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, |
| 60 | * it goes through TRACED -> RUNNING -> STOPPED transition which is similar |
| 61 | * to but in the opposite direction of what happens while attaching to a |
| 62 | * stopped task. However, in this direction, the intermediate RUNNING |
| 63 | * state is not hidden even from the current ptracer and if it immediately |
| 64 | * re-attaches and performs a WNOHANG wait(2), it may fail. |
Tejun Heo | e3bd058 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 65 | * |
| 66 | * CONTEXT: |
| 67 | * write_lock_irq(tasklist_lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | */ |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 69 | void __ptrace_unlink(struct task_struct *child) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | { |
Oleg Nesterov | 5ecfbae | 2006-02-15 22:50:10 +0300 | [diff] [blame] | 71 | BUG_ON(!child->ptrace); |
| 72 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | child->ptrace = 0; |
Roland McGrath | f470021 | 2008-03-24 18:36:23 -0700 | [diff] [blame] | 74 | child->parent = child->real_parent; |
| 75 | list_del_init(&child->ptrace_entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | spin_lock(&child->sighand->siglock); |
Tejun Heo | 0e9f0a4 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 78 | |
| 79 | /* |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 80 | * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and |
Tejun Heo | 0e9f0a4 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 81 | * @child isn't dead. |
| 82 | */ |
| 83 | if (!(child->flags & PF_EXITING) && |
| 84 | (child->signal->flags & SIGNAL_STOP_STOPPED || |
| 85 | child->signal->group_stop_count)) |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 86 | child->jobctl |= JOBCTL_STOP_PENDING; |
Tejun Heo | 0e9f0a4 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 87 | |
| 88 | /* |
| 89 | * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick |
| 90 | * @child in the butt. Note that @resume should be used iff @child |
| 91 | * is in TASK_TRACED; otherwise, we might unduly disrupt |
| 92 | * TASK_KILLABLE sleeps. |
| 93 | */ |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 94 | if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) |
Tejun Heo | 0e9f0a4 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 95 | signal_wake_up(child, task_is_traced(child)); |
| 96 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | spin_unlock(&child->sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | } |
| 99 | |
Tejun Heo | 755e276 | 2011-06-02 11:13:59 +0200 | [diff] [blame^] | 100 | /** |
| 101 | * ptrace_check_attach - check whether ptracee is ready for ptrace operation |
| 102 | * @child: ptracee to check for |
| 103 | * @ignore_state: don't check whether @child is currently %TASK_TRACED |
| 104 | * |
| 105 | * Check whether @child is being ptraced by %current and ready for further |
| 106 | * ptrace operations. If @ignore_state is %false, @child also should be in |
| 107 | * %TASK_TRACED state and on return the child is guaranteed to be traced |
| 108 | * and not executing. If @ignore_state is %true, @child can be in any |
| 109 | * state. |
| 110 | * |
| 111 | * CONTEXT: |
| 112 | * Grabs and releases tasklist_lock and @child->sighand->siglock. |
| 113 | * |
| 114 | * RETURNS: |
| 115 | * 0 on success, -ESRCH if %child is not ready. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | */ |
Tejun Heo | 755e276 | 2011-06-02 11:13:59 +0200 | [diff] [blame^] | 117 | int ptrace_check_attach(struct task_struct *child, bool ignore_state) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | { |
| 119 | int ret = -ESRCH; |
| 120 | |
| 121 | /* |
| 122 | * We take the read lock around doing both checks to close a |
| 123 | * possible race where someone else was tracing our child and |
| 124 | * detached between these two checks. After this locked check, |
| 125 | * we are sure that this is our traced child and that can only |
| 126 | * be changed by us so it's not changing right after this. |
| 127 | */ |
| 128 | read_lock(&tasklist_lock); |
Oleg Nesterov | c0c0b64 | 2008-02-08 04:19:00 -0800 | [diff] [blame] | 129 | if ((child->ptrace & PT_PTRACED) && child->parent == current) { |
Oleg Nesterov | c0c0b64 | 2008-02-08 04:19:00 -0800 | [diff] [blame] | 130 | /* |
| 131 | * child->sighand can't be NULL, release_task() |
| 132 | * does ptrace_unlink() before __exit_signal(). |
| 133 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | spin_lock_irq(&child->sighand->siglock); |
Oleg Nesterov | 321fb56 | 2011-04-01 20:13:01 +0200 | [diff] [blame] | 135 | WARN_ON_ONCE(task_is_stopped(child)); |
Tejun Heo | 755e276 | 2011-06-02 11:13:59 +0200 | [diff] [blame^] | 136 | if (task_is_traced(child) || ignore_state) |
Oleg Nesterov | 321fb56 | 2011-04-01 20:13:01 +0200 | [diff] [blame] | 137 | ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | spin_unlock_irq(&child->sighand->siglock); |
| 139 | } |
| 140 | read_unlock(&tasklist_lock); |
| 141 | |
Tejun Heo | 755e276 | 2011-06-02 11:13:59 +0200 | [diff] [blame^] | 142 | if (!ret && !ignore_state) |
Roland McGrath | 85ba2d8 | 2008-07-25 19:45:58 -0700 | [diff] [blame] | 143 | ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | |
| 145 | /* All systems go.. */ |
| 146 | return ret; |
| 147 | } |
| 148 | |
Stephen Smalley | 006ebb4 | 2008-05-19 08:32:49 -0400 | [diff] [blame] | 149 | int __ptrace_may_access(struct task_struct *task, unsigned int mode) |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 150 | { |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 151 | const struct cred *cred = current_cred(), *tcred; |
David Howells | b6dff3e | 2008-11-14 10:39:16 +1100 | [diff] [blame] | 152 | |
Eric W. Biederman | df26c40 | 2006-06-26 00:25:59 -0700 | [diff] [blame] | 153 | /* May we inspect the given task? |
| 154 | * This check is used both for attaching with ptrace |
| 155 | * and for allowing access to sensitive information in /proc. |
| 156 | * |
| 157 | * ptrace_attach denies several cases that /proc allows |
| 158 | * because setting up the necessary parent/child relationship |
| 159 | * or halting the specified task is impossible. |
| 160 | */ |
| 161 | int dumpable = 0; |
| 162 | /* Don't let security modules deny introspection */ |
| 163 | if (task == current) |
| 164 | return 0; |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 165 | rcu_read_lock(); |
| 166 | tcred = __task_cred(task); |
Serge E. Hallyn | 8409cca | 2011-03-23 16:43:20 -0700 | [diff] [blame] | 167 | if (cred->user->user_ns == tcred->user->user_ns && |
| 168 | (cred->uid == tcred->euid && |
| 169 | cred->uid == tcred->suid && |
| 170 | cred->uid == tcred->uid && |
| 171 | cred->gid == tcred->egid && |
| 172 | cred->gid == tcred->sgid && |
| 173 | cred->gid == tcred->gid)) |
| 174 | goto ok; |
| 175 | if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE)) |
| 176 | goto ok; |
| 177 | rcu_read_unlock(); |
| 178 | return -EPERM; |
| 179 | ok: |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 180 | rcu_read_unlock(); |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 181 | smp_rmb(); |
Eric W. Biederman | df26c40 | 2006-06-26 00:25:59 -0700 | [diff] [blame] | 182 | if (task->mm) |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 183 | dumpable = get_dumpable(task->mm); |
Serge E. Hallyn | 8409cca | 2011-03-23 16:43:20 -0700 | [diff] [blame] | 184 | if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE)) |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 185 | return -EPERM; |
| 186 | |
Ingo Molnar | 9e48858 | 2009-05-07 19:26:19 +1000 | [diff] [blame] | 187 | return security_ptrace_access_check(task, mode); |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 188 | } |
| 189 | |
Stephen Smalley | 006ebb4 | 2008-05-19 08:32:49 -0400 | [diff] [blame] | 190 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 191 | { |
| 192 | int err; |
| 193 | task_lock(task); |
Stephen Smalley | 006ebb4 | 2008-05-19 08:32:49 -0400 | [diff] [blame] | 194 | err = __ptrace_may_access(task, mode); |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 195 | task_unlock(task); |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 196 | return !err; |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 197 | } |
| 198 | |
Linus Torvalds | e3e89cc | 2011-03-04 09:23:30 -0800 | [diff] [blame] | 199 | static int ptrace_attach(struct task_struct *task) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | { |
| 201 | int retval; |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 202 | |
Al Viro | a5cb013 | 2007-03-20 13:58:35 -0400 | [diff] [blame] | 203 | audit_ptrace(task); |
| 204 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | retval = -EPERM; |
Oleg Nesterov | b79b7ba | 2009-06-17 16:27:31 -0700 | [diff] [blame] | 206 | if (unlikely(task->flags & PF_KTHREAD)) |
| 207 | goto out; |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 208 | if (same_thread_group(task, current)) |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 209 | goto out; |
| 210 | |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 211 | /* |
| 212 | * Protect exec's credential calculations against our interference; |
David Howells | 5e751e9 | 2009-05-08 13:55:22 +0100 | [diff] [blame] | 213 | * interference; SUID, SGID and LSM creds get determined differently |
| 214 | * under ptrace. |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 215 | */ |
Oleg Nesterov | 793285f | 2009-07-05 12:08:26 -0700 | [diff] [blame] | 216 | retval = -ERESTARTNOINTR; |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 217 | if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 218 | goto out; |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 219 | |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 220 | task_lock(task); |
Stephen Smalley | 006ebb4 | 2008-05-19 08:32:49 -0400 | [diff] [blame] | 221 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 222 | task_unlock(task); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | if (retval) |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 224 | goto unlock_creds; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 226 | write_lock_irq(&tasklist_lock); |
Oleg Nesterov | b79b7ba | 2009-06-17 16:27:31 -0700 | [diff] [blame] | 227 | retval = -EPERM; |
| 228 | if (unlikely(task->exit_state)) |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 229 | goto unlock_tasklist; |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 230 | if (task->ptrace) |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 231 | goto unlock_tasklist; |
Oleg Nesterov | b79b7ba | 2009-06-17 16:27:31 -0700 | [diff] [blame] | 232 | |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 233 | task->ptrace = PT_PTRACED; |
Serge E. Hallyn | 8409cca | 2011-03-23 16:43:20 -0700 | [diff] [blame] | 234 | if (task_ns_capable(task, CAP_SYS_PTRACE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | task->ptrace |= PT_PTRACE_CAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | __ptrace_link(task, current); |
Oleg Nesterov | 33e9fc7 | 2008-04-30 00:53:14 -0700 | [diff] [blame] | 238 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); |
Oleg Nesterov | b79b7ba | 2009-06-17 16:27:31 -0700 | [diff] [blame] | 239 | |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 240 | spin_lock(&task->sighand->siglock); |
| 241 | |
| 242 | /* |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 243 | * If the task is already STOPPED, set JOBCTL_STOP_PENDING and |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 244 | * TRAPPING, and kick it so that it transits to TRACED. TRAPPING |
| 245 | * will be cleared if the child completes the transition or any |
| 246 | * event which clears the group stop states happens. We'll wait |
| 247 | * for the transition to complete before returning from this |
| 248 | * function. |
| 249 | * |
| 250 | * This hides STOPPED -> RUNNING -> TRACED transition from the |
| 251 | * attaching thread but a different thread in the same group can |
| 252 | * still observe the transient RUNNING state. IOW, if another |
| 253 | * thread's WNOHANG wait(2) on the stopped tracee races against |
| 254 | * ATTACH, the wait(2) may fail due to the transient RUNNING. |
| 255 | * |
| 256 | * The following task_is_stopped() test is safe as both transitions |
| 257 | * in and out of STOPPED are protected by siglock. |
| 258 | */ |
| 259 | if (task_is_stopped(task)) { |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 260 | task->jobctl |= JOBCTL_STOP_PENDING | JOBCTL_TRAPPING; |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 261 | signal_wake_up(task, 1); |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 262 | } |
| 263 | |
| 264 | spin_unlock(&task->sighand->siglock); |
| 265 | |
Oleg Nesterov | b79b7ba | 2009-06-17 16:27:31 -0700 | [diff] [blame] | 266 | retval = 0; |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 267 | unlock_tasklist: |
| 268 | write_unlock_irq(&tasklist_lock); |
| 269 | unlock_creds: |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 270 | mutex_unlock(&task->signal->cred_guard_mutex); |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 271 | out: |
Tejun Heo | 0b1007c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 272 | if (!retval) |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 273 | wait_event(current->signal->wait_chldexit, |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 274 | !(task->jobctl & JOBCTL_TRAPPING)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | return retval; |
| 276 | } |
| 277 | |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 278 | /** |
| 279 | * ptrace_traceme -- helper for PTRACE_TRACEME |
| 280 | * |
| 281 | * Performs checks and sets PT_PTRACED. |
| 282 | * Should be used by all ptrace implementations for PTRACE_TRACEME. |
| 283 | */ |
Linus Torvalds | e3e89cc | 2011-03-04 09:23:30 -0800 | [diff] [blame] | 284 | static int ptrace_traceme(void) |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 285 | { |
| 286 | int ret = -EPERM; |
| 287 | |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 288 | write_lock_irq(&tasklist_lock); |
| 289 | /* Are we already being traced? */ |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 290 | if (!current->ptrace) { |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 291 | ret = security_ptrace_traceme(current->parent); |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 292 | /* |
| 293 | * Check PF_EXITING to ensure ->real_parent has not passed |
| 294 | * exit_ptrace(). Otherwise we don't report the error but |
| 295 | * pretend ->real_parent untraces us right after return. |
| 296 | */ |
| 297 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { |
| 298 | current->ptrace = PT_PTRACED; |
| 299 | __ptrace_link(current, current->real_parent); |
| 300 | } |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 301 | } |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 302 | write_unlock_irq(&tasklist_lock); |
| 303 | |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 304 | return ret; |
| 305 | } |
| 306 | |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 307 | /* |
| 308 | * Called with irqs disabled, returns true if childs should reap themselves. |
| 309 | */ |
| 310 | static int ignoring_children(struct sighand_struct *sigh) |
| 311 | { |
| 312 | int ret; |
| 313 | spin_lock(&sigh->siglock); |
| 314 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || |
| 315 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); |
| 316 | spin_unlock(&sigh->siglock); |
| 317 | return ret; |
| 318 | } |
| 319 | |
| 320 | /* |
| 321 | * Called with tasklist_lock held for writing. |
| 322 | * Unlink a traced task, and clean it up if it was a traced zombie. |
| 323 | * Return true if it needs to be reaped with release_task(). |
| 324 | * (We can't call release_task() here because we already hold tasklist_lock.) |
| 325 | * |
| 326 | * If it's a zombie, our attachedness prevented normal parent notification |
| 327 | * or self-reaping. Do notification now if it would have happened earlier. |
| 328 | * If it should reap itself, return true. |
| 329 | * |
Oleg Nesterov | a7f0765 | 2009-09-23 15:56:44 -0700 | [diff] [blame] | 330 | * If it's our own child, there is no notification to do. But if our normal |
| 331 | * children self-reap, then this child was prevented by ptrace and we must |
| 332 | * reap it now, in that case we must also wake up sub-threads sleeping in |
| 333 | * do_wait(). |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 334 | */ |
| 335 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) |
| 336 | { |
| 337 | __ptrace_unlink(p); |
| 338 | |
| 339 | if (p->exit_state == EXIT_ZOMBIE) { |
| 340 | if (!task_detached(p) && thread_group_empty(p)) { |
| 341 | if (!same_thread_group(p->real_parent, tracer)) |
| 342 | do_notify_parent(p, p->exit_signal); |
Oleg Nesterov | a7f0765 | 2009-09-23 15:56:44 -0700 | [diff] [blame] | 343 | else if (ignoring_children(tracer->sighand)) { |
| 344 | __wake_up_parent(p, tracer); |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 345 | p->exit_signal = -1; |
Oleg Nesterov | a7f0765 | 2009-09-23 15:56:44 -0700 | [diff] [blame] | 346 | } |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 347 | } |
| 348 | if (task_detached(p)) { |
| 349 | /* Mark it as in the process of being reaped. */ |
| 350 | p->exit_state = EXIT_DEAD; |
| 351 | return true; |
| 352 | } |
| 353 | } |
| 354 | |
| 355 | return false; |
| 356 | } |
| 357 | |
Linus Torvalds | e3e89cc | 2011-03-04 09:23:30 -0800 | [diff] [blame] | 358 | static int ptrace_detach(struct task_struct *child, unsigned int data) |
Oleg Nesterov | 5ecfbae | 2006-02-15 22:50:10 +0300 | [diff] [blame] | 359 | { |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 360 | bool dead = false; |
Oleg Nesterov | 4576145 | 2009-04-02 16:58:14 -0700 | [diff] [blame] | 361 | |
Oleg Nesterov | 5ecfbae | 2006-02-15 22:50:10 +0300 | [diff] [blame] | 362 | if (!valid_signal(data)) |
| 363 | return -EIO; |
| 364 | |
| 365 | /* Architecture-specific hardware disable .. */ |
| 366 | ptrace_disable(child); |
Roland McGrath | 7d94143 | 2007-09-05 03:05:56 -0700 | [diff] [blame] | 367 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
Oleg Nesterov | 5ecfbae | 2006-02-15 22:50:10 +0300 | [diff] [blame] | 368 | |
Oleg Nesterov | 95c3eb7 | 2009-04-02 16:58:11 -0700 | [diff] [blame] | 369 | write_lock_irq(&tasklist_lock); |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 370 | /* |
| 371 | * This child can be already killed. Make sure de_thread() or |
| 372 | * our sub-thread doing do_wait() didn't do release_task() yet. |
| 373 | */ |
Oleg Nesterov | 95c3eb7 | 2009-04-02 16:58:11 -0700 | [diff] [blame] | 374 | if (child->ptrace) { |
| 375 | child->exit_code = data; |
Oleg Nesterov | 4576145 | 2009-04-02 16:58:14 -0700 | [diff] [blame] | 376 | dead = __ptrace_detach(current, child); |
Oleg Nesterov | 95c3eb7 | 2009-04-02 16:58:11 -0700 | [diff] [blame] | 377 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 378 | write_unlock_irq(&tasklist_lock); |
| 379 | |
Oleg Nesterov | 4576145 | 2009-04-02 16:58:14 -0700 | [diff] [blame] | 380 | if (unlikely(dead)) |
| 381 | release_task(child); |
| 382 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | return 0; |
| 384 | } |
| 385 | |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 386 | /* |
Oleg Nesterov | c7e49c1 | 2010-08-10 18:03:07 -0700 | [diff] [blame] | 387 | * Detach all tasks we were using ptrace on. Called with tasklist held |
| 388 | * for writing, and returns with it held too. But note it can release |
| 389 | * and reacquire the lock. |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 390 | */ |
| 391 | void exit_ptrace(struct task_struct *tracer) |
Namhyung Kim | c4b5ed2 | 2010-10-27 15:33:44 -0700 | [diff] [blame] | 392 | __releases(&tasklist_lock) |
| 393 | __acquires(&tasklist_lock) |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 394 | { |
| 395 | struct task_struct *p, *n; |
| 396 | LIST_HEAD(ptrace_dead); |
| 397 | |
Oleg Nesterov | c7e49c1 | 2010-08-10 18:03:07 -0700 | [diff] [blame] | 398 | if (likely(list_empty(&tracer->ptraced))) |
| 399 | return; |
| 400 | |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 401 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
| 402 | if (__ptrace_detach(tracer, p)) |
| 403 | list_add(&p->ptrace_entry, &ptrace_dead); |
| 404 | } |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 405 | |
Oleg Nesterov | c7e49c1 | 2010-08-10 18:03:07 -0700 | [diff] [blame] | 406 | write_unlock_irq(&tasklist_lock); |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 407 | BUG_ON(!list_empty(&tracer->ptraced)); |
| 408 | |
| 409 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { |
| 410 | list_del_init(&p->ptrace_entry); |
| 411 | release_task(p); |
| 412 | } |
Oleg Nesterov | c7e49c1 | 2010-08-10 18:03:07 -0700 | [diff] [blame] | 413 | |
| 414 | write_lock_irq(&tasklist_lock); |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 415 | } |
| 416 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
| 418 | { |
| 419 | int copied = 0; |
| 420 | |
| 421 | while (len > 0) { |
| 422 | char buf[128]; |
| 423 | int this_len, retval; |
| 424 | |
| 425 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; |
| 426 | retval = access_process_vm(tsk, src, buf, this_len, 0); |
| 427 | if (!retval) { |
| 428 | if (copied) |
| 429 | break; |
| 430 | return -EIO; |
| 431 | } |
| 432 | if (copy_to_user(dst, buf, retval)) |
| 433 | return -EFAULT; |
| 434 | copied += retval; |
| 435 | src += retval; |
| 436 | dst += retval; |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 437 | len -= retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | } |
| 439 | return copied; |
| 440 | } |
| 441 | |
| 442 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) |
| 443 | { |
| 444 | int copied = 0; |
| 445 | |
| 446 | while (len > 0) { |
| 447 | char buf[128]; |
| 448 | int this_len, retval; |
| 449 | |
| 450 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; |
| 451 | if (copy_from_user(buf, src, this_len)) |
| 452 | return -EFAULT; |
| 453 | retval = access_process_vm(tsk, dst, buf, this_len, 1); |
| 454 | if (!retval) { |
| 455 | if (copied) |
| 456 | break; |
| 457 | return -EIO; |
| 458 | } |
| 459 | copied += retval; |
| 460 | src += retval; |
| 461 | dst += retval; |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 462 | len -= retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | } |
| 464 | return copied; |
| 465 | } |
| 466 | |
Namhyung Kim | 4abf986 | 2010-10-27 15:33:45 -0700 | [diff] [blame] | 467 | static int ptrace_setoptions(struct task_struct *child, unsigned long data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | { |
| 469 | child->ptrace &= ~PT_TRACE_MASK; |
| 470 | |
| 471 | if (data & PTRACE_O_TRACESYSGOOD) |
| 472 | child->ptrace |= PT_TRACESYSGOOD; |
| 473 | |
| 474 | if (data & PTRACE_O_TRACEFORK) |
| 475 | child->ptrace |= PT_TRACE_FORK; |
| 476 | |
| 477 | if (data & PTRACE_O_TRACEVFORK) |
| 478 | child->ptrace |= PT_TRACE_VFORK; |
| 479 | |
| 480 | if (data & PTRACE_O_TRACECLONE) |
| 481 | child->ptrace |= PT_TRACE_CLONE; |
| 482 | |
| 483 | if (data & PTRACE_O_TRACEEXEC) |
| 484 | child->ptrace |= PT_TRACE_EXEC; |
| 485 | |
| 486 | if (data & PTRACE_O_TRACEVFORKDONE) |
| 487 | child->ptrace |= PT_TRACE_VFORK_DONE; |
| 488 | |
| 489 | if (data & PTRACE_O_TRACEEXIT) |
| 490 | child->ptrace |= PT_TRACE_EXIT; |
| 491 | |
| 492 | return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; |
| 493 | } |
| 494 | |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 495 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | { |
Oleg Nesterov | e496125 | 2009-06-17 16:27:36 -0700 | [diff] [blame] | 497 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | int error = -ESRCH; |
| 499 | |
Oleg Nesterov | e496125 | 2009-06-17 16:27:36 -0700 | [diff] [blame] | 500 | if (lock_task_sighand(child, &flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | error = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | if (likely(child->last_siginfo != NULL)) { |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 503 | *info = *child->last_siginfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | error = 0; |
| 505 | } |
Oleg Nesterov | e496125 | 2009-06-17 16:27:36 -0700 | [diff] [blame] | 506 | unlock_task_sighand(child, &flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 507 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | return error; |
| 509 | } |
| 510 | |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 511 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | { |
Oleg Nesterov | e496125 | 2009-06-17 16:27:36 -0700 | [diff] [blame] | 513 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | int error = -ESRCH; |
| 515 | |
Oleg Nesterov | e496125 | 2009-06-17 16:27:36 -0700 | [diff] [blame] | 516 | if (lock_task_sighand(child, &flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | error = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | if (likely(child->last_siginfo != NULL)) { |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 519 | *child->last_siginfo = *info; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | error = 0; |
| 521 | } |
Oleg Nesterov | e496125 | 2009-06-17 16:27:36 -0700 | [diff] [blame] | 522 | unlock_task_sighand(child, &flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 524 | return error; |
| 525 | } |
| 526 | |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 527 | |
| 528 | #ifdef PTRACE_SINGLESTEP |
| 529 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) |
| 530 | #else |
| 531 | #define is_singlestep(request) 0 |
| 532 | #endif |
| 533 | |
Roland McGrath | 5b88abb | 2008-01-30 13:30:53 +0100 | [diff] [blame] | 534 | #ifdef PTRACE_SINGLEBLOCK |
| 535 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) |
| 536 | #else |
| 537 | #define is_singleblock(request) 0 |
| 538 | #endif |
| 539 | |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 540 | #ifdef PTRACE_SYSEMU |
| 541 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) |
| 542 | #else |
| 543 | #define is_sysemu_singlestep(request) 0 |
| 544 | #endif |
| 545 | |
Namhyung Kim | 4abf986 | 2010-10-27 15:33:45 -0700 | [diff] [blame] | 546 | static int ptrace_resume(struct task_struct *child, long request, |
| 547 | unsigned long data) |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 548 | { |
| 549 | if (!valid_signal(data)) |
| 550 | return -EIO; |
| 551 | |
| 552 | if (request == PTRACE_SYSCALL) |
| 553 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 554 | else |
| 555 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 556 | |
| 557 | #ifdef TIF_SYSCALL_EMU |
| 558 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) |
| 559 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); |
| 560 | else |
| 561 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); |
| 562 | #endif |
| 563 | |
Roland McGrath | 5b88abb | 2008-01-30 13:30:53 +0100 | [diff] [blame] | 564 | if (is_singleblock(request)) { |
| 565 | if (unlikely(!arch_has_block_step())) |
| 566 | return -EIO; |
| 567 | user_enable_block_step(child); |
| 568 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 569 | if (unlikely(!arch_has_single_step())) |
| 570 | return -EIO; |
| 571 | user_enable_single_step(child); |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 572 | } else { |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 573 | user_disable_single_step(child); |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 574 | } |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 575 | |
| 576 | child->exit_code = data; |
Oleg Nesterov | 0666fb5 | 2011-05-25 19:20:21 +0200 | [diff] [blame] | 577 | wake_up_state(child, __TASK_TRACED); |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 578 | |
| 579 | return 0; |
| 580 | } |
| 581 | |
Suresh Siddha | 2225a12 | 2010-02-11 11:51:00 -0800 | [diff] [blame] | 582 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
| 583 | |
| 584 | static const struct user_regset * |
| 585 | find_regset(const struct user_regset_view *view, unsigned int type) |
| 586 | { |
| 587 | const struct user_regset *regset; |
| 588 | int n; |
| 589 | |
| 590 | for (n = 0; n < view->n; ++n) { |
| 591 | regset = view->regsets + n; |
| 592 | if (regset->core_note_type == type) |
| 593 | return regset; |
| 594 | } |
| 595 | |
| 596 | return NULL; |
| 597 | } |
| 598 | |
| 599 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, |
| 600 | struct iovec *kiov) |
| 601 | { |
| 602 | const struct user_regset_view *view = task_user_regset_view(task); |
| 603 | const struct user_regset *regset = find_regset(view, type); |
| 604 | int regset_no; |
| 605 | |
| 606 | if (!regset || (kiov->iov_len % regset->size) != 0) |
Suresh Siddha | c6a0dd7 | 2010-02-22 14:51:32 -0800 | [diff] [blame] | 607 | return -EINVAL; |
Suresh Siddha | 2225a12 | 2010-02-11 11:51:00 -0800 | [diff] [blame] | 608 | |
| 609 | regset_no = regset - view->regsets; |
| 610 | kiov->iov_len = min(kiov->iov_len, |
| 611 | (__kernel_size_t) (regset->n * regset->size)); |
| 612 | |
| 613 | if (req == PTRACE_GETREGSET) |
| 614 | return copy_regset_to_user(task, view, regset_no, 0, |
| 615 | kiov->iov_len, kiov->iov_base); |
| 616 | else |
| 617 | return copy_regset_from_user(task, view, regset_no, 0, |
| 618 | kiov->iov_len, kiov->iov_base); |
| 619 | } |
| 620 | |
| 621 | #endif |
| 622 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | int ptrace_request(struct task_struct *child, long request, |
Namhyung Kim | 4abf986 | 2010-10-27 15:33:45 -0700 | [diff] [blame] | 624 | unsigned long addr, unsigned long data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 625 | { |
| 626 | int ret = -EIO; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 627 | siginfo_t siginfo; |
Namhyung Kim | 9fed81d | 2010-10-27 15:33:46 -0700 | [diff] [blame] | 628 | void __user *datavp = (void __user *) data; |
| 629 | unsigned long __user *datalp = datavp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 630 | |
| 631 | switch (request) { |
Roland McGrath | 16c3e38 | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 632 | case PTRACE_PEEKTEXT: |
| 633 | case PTRACE_PEEKDATA: |
| 634 | return generic_ptrace_peekdata(child, addr, data); |
| 635 | case PTRACE_POKETEXT: |
| 636 | case PTRACE_POKEDATA: |
| 637 | return generic_ptrace_pokedata(child, addr, data); |
| 638 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 639 | #ifdef PTRACE_OLDSETOPTIONS |
| 640 | case PTRACE_OLDSETOPTIONS: |
| 641 | #endif |
| 642 | case PTRACE_SETOPTIONS: |
| 643 | ret = ptrace_setoptions(child, data); |
| 644 | break; |
| 645 | case PTRACE_GETEVENTMSG: |
Namhyung Kim | 9fed81d | 2010-10-27 15:33:46 -0700 | [diff] [blame] | 646 | ret = put_user(child->ptrace_message, datalp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | break; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 648 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 649 | case PTRACE_GETSIGINFO: |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 650 | ret = ptrace_getsiginfo(child, &siginfo); |
| 651 | if (!ret) |
Namhyung Kim | 9fed81d | 2010-10-27 15:33:46 -0700 | [diff] [blame] | 652 | ret = copy_siginfo_to_user(datavp, &siginfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | break; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 654 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | case PTRACE_SETSIGINFO: |
Namhyung Kim | 9fed81d | 2010-10-27 15:33:46 -0700 | [diff] [blame] | 656 | if (copy_from_user(&siginfo, datavp, sizeof siginfo)) |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 657 | ret = -EFAULT; |
| 658 | else |
| 659 | ret = ptrace_setsiginfo(child, &siginfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | break; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 661 | |
Alexey Dobriyan | 1bcf548 | 2007-10-16 01:23:45 -0700 | [diff] [blame] | 662 | case PTRACE_DETACH: /* detach a process that was attached. */ |
| 663 | ret = ptrace_detach(child, data); |
| 664 | break; |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 665 | |
Mike Frysinger | 9c1a125 | 2010-05-26 14:42:52 -0700 | [diff] [blame] | 666 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
| 667 | case PTRACE_GETFDPIC: { |
Oleg Nesterov | e0129ef | 2010-05-26 14:42:53 -0700 | [diff] [blame] | 668 | struct mm_struct *mm = get_task_mm(child); |
Mike Frysinger | 9c1a125 | 2010-05-26 14:42:52 -0700 | [diff] [blame] | 669 | unsigned long tmp = 0; |
| 670 | |
Oleg Nesterov | e0129ef | 2010-05-26 14:42:53 -0700 | [diff] [blame] | 671 | ret = -ESRCH; |
| 672 | if (!mm) |
| 673 | break; |
| 674 | |
Mike Frysinger | 9c1a125 | 2010-05-26 14:42:52 -0700 | [diff] [blame] | 675 | switch (addr) { |
| 676 | case PTRACE_GETFDPIC_EXEC: |
Oleg Nesterov | e0129ef | 2010-05-26 14:42:53 -0700 | [diff] [blame] | 677 | tmp = mm->context.exec_fdpic_loadmap; |
Mike Frysinger | 9c1a125 | 2010-05-26 14:42:52 -0700 | [diff] [blame] | 678 | break; |
| 679 | case PTRACE_GETFDPIC_INTERP: |
Oleg Nesterov | e0129ef | 2010-05-26 14:42:53 -0700 | [diff] [blame] | 680 | tmp = mm->context.interp_fdpic_loadmap; |
Mike Frysinger | 9c1a125 | 2010-05-26 14:42:52 -0700 | [diff] [blame] | 681 | break; |
| 682 | default: |
| 683 | break; |
| 684 | } |
Oleg Nesterov | e0129ef | 2010-05-26 14:42:53 -0700 | [diff] [blame] | 685 | mmput(mm); |
Mike Frysinger | 9c1a125 | 2010-05-26 14:42:52 -0700 | [diff] [blame] | 686 | |
Namhyung Kim | 9fed81d | 2010-10-27 15:33:46 -0700 | [diff] [blame] | 687 | ret = put_user(tmp, datalp); |
Mike Frysinger | 9c1a125 | 2010-05-26 14:42:52 -0700 | [diff] [blame] | 688 | break; |
| 689 | } |
| 690 | #endif |
| 691 | |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 692 | #ifdef PTRACE_SINGLESTEP |
| 693 | case PTRACE_SINGLESTEP: |
| 694 | #endif |
Roland McGrath | 5b88abb | 2008-01-30 13:30:53 +0100 | [diff] [blame] | 695 | #ifdef PTRACE_SINGLEBLOCK |
| 696 | case PTRACE_SINGLEBLOCK: |
| 697 | #endif |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 698 | #ifdef PTRACE_SYSEMU |
| 699 | case PTRACE_SYSEMU: |
| 700 | case PTRACE_SYSEMU_SINGLESTEP: |
| 701 | #endif |
| 702 | case PTRACE_SYSCALL: |
| 703 | case PTRACE_CONT: |
| 704 | return ptrace_resume(child, request, data); |
| 705 | |
| 706 | case PTRACE_KILL: |
| 707 | if (child->exit_state) /* already dead */ |
| 708 | return 0; |
| 709 | return ptrace_resume(child, request, SIGKILL); |
| 710 | |
Suresh Siddha | 2225a12 | 2010-02-11 11:51:00 -0800 | [diff] [blame] | 711 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
| 712 | case PTRACE_GETREGSET: |
| 713 | case PTRACE_SETREGSET: |
| 714 | { |
| 715 | struct iovec kiov; |
Namhyung Kim | 9fed81d | 2010-10-27 15:33:46 -0700 | [diff] [blame] | 716 | struct iovec __user *uiov = datavp; |
Suresh Siddha | 2225a12 | 2010-02-11 11:51:00 -0800 | [diff] [blame] | 717 | |
| 718 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) |
| 719 | return -EFAULT; |
| 720 | |
| 721 | if (__get_user(kiov.iov_base, &uiov->iov_base) || |
| 722 | __get_user(kiov.iov_len, &uiov->iov_len)) |
| 723 | return -EFAULT; |
| 724 | |
| 725 | ret = ptrace_regset(child, request, addr, &kiov); |
| 726 | if (!ret) |
| 727 | ret = __put_user(kiov.iov_len, &uiov->iov_len); |
| 728 | break; |
| 729 | } |
| 730 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 731 | default: |
| 732 | break; |
| 733 | } |
| 734 | |
| 735 | return ret; |
| 736 | } |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 737 | |
Oleg Nesterov | 8053bdd | 2009-06-17 16:27:34 -0700 | [diff] [blame] | 738 | static struct task_struct *ptrace_get_task_struct(pid_t pid) |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 739 | { |
| 740 | struct task_struct *child; |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 741 | |
Oleg Nesterov | 8053bdd | 2009-06-17 16:27:34 -0700 | [diff] [blame] | 742 | rcu_read_lock(); |
Pavel Emelyanov | 228ebcb | 2007-10-18 23:40:16 -0700 | [diff] [blame] | 743 | child = find_task_by_vpid(pid); |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 744 | if (child) |
| 745 | get_task_struct(child); |
Oleg Nesterov | 8053bdd | 2009-06-17 16:27:34 -0700 | [diff] [blame] | 746 | rcu_read_unlock(); |
Sukadev Bhattiprolu | f400e19 | 2006-09-29 02:00:07 -0700 | [diff] [blame] | 747 | |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 748 | if (!child) |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 749 | return ERR_PTR(-ESRCH); |
| 750 | return child; |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 751 | } |
| 752 | |
Christoph Hellwig | 0ac1555 | 2007-10-16 01:26:37 -0700 | [diff] [blame] | 753 | #ifndef arch_ptrace_attach |
| 754 | #define arch_ptrace_attach(child) do { } while (0) |
| 755 | #endif |
| 756 | |
Namhyung Kim | 4abf986 | 2010-10-27 15:33:45 -0700 | [diff] [blame] | 757 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, |
| 758 | unsigned long, data) |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 759 | { |
| 760 | struct task_struct *child; |
| 761 | long ret; |
| 762 | |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 763 | if (request == PTRACE_TRACEME) { |
| 764 | ret = ptrace_traceme(); |
Haavard Skinnemoen | 6ea6dd9 | 2007-11-27 13:02:40 +0100 | [diff] [blame] | 765 | if (!ret) |
| 766 | arch_ptrace_attach(current); |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 767 | goto out; |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 768 | } |
| 769 | |
| 770 | child = ptrace_get_task_struct(pid); |
| 771 | if (IS_ERR(child)) { |
| 772 | ret = PTR_ERR(child); |
| 773 | goto out; |
| 774 | } |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 775 | |
| 776 | if (request == PTRACE_ATTACH) { |
| 777 | ret = ptrace_attach(child); |
Christoph Hellwig | 0ac1555 | 2007-10-16 01:26:37 -0700 | [diff] [blame] | 778 | /* |
| 779 | * Some architectures need to do book-keeping after |
| 780 | * a ptrace attach. |
| 781 | */ |
| 782 | if (!ret) |
| 783 | arch_ptrace_attach(child); |
Christoph Hellwig | 005f18d | 2005-11-13 16:06:33 -0800 | [diff] [blame] | 784 | goto out_put_task_struct; |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 785 | } |
| 786 | |
| 787 | ret = ptrace_check_attach(child, request == PTRACE_KILL); |
| 788 | if (ret < 0) |
| 789 | goto out_put_task_struct; |
| 790 | |
| 791 | ret = arch_ptrace(child, request, addr, data); |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 792 | |
| 793 | out_put_task_struct: |
| 794 | put_task_struct(child); |
| 795 | out: |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 796 | return ret; |
| 797 | } |
Alexey Dobriyan | 7664732 | 2007-07-17 04:03:43 -0700 | [diff] [blame] | 798 | |
Namhyung Kim | 4abf986 | 2010-10-27 15:33:45 -0700 | [diff] [blame] | 799 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
| 800 | unsigned long data) |
Alexey Dobriyan | 7664732 | 2007-07-17 04:03:43 -0700 | [diff] [blame] | 801 | { |
| 802 | unsigned long tmp; |
| 803 | int copied; |
| 804 | |
| 805 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); |
| 806 | if (copied != sizeof(tmp)) |
| 807 | return -EIO; |
| 808 | return put_user(tmp, (unsigned long __user *)data); |
| 809 | } |
Alexey Dobriyan | f284ce7 | 2007-07-17 04:03:44 -0700 | [diff] [blame] | 810 | |
Namhyung Kim | 4abf986 | 2010-10-27 15:33:45 -0700 | [diff] [blame] | 811 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
| 812 | unsigned long data) |
Alexey Dobriyan | f284ce7 | 2007-07-17 04:03:44 -0700 | [diff] [blame] | 813 | { |
| 814 | int copied; |
| 815 | |
| 816 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); |
| 817 | return (copied == sizeof(data)) ? 0 : -EIO; |
| 818 | } |
Roland McGrath | 032d82d | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 819 | |
Christoph Hellwig | 96b8936 | 2008-11-25 08:10:03 +0100 | [diff] [blame] | 820 | #if defined CONFIG_COMPAT |
Roland McGrath | 032d82d | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 821 | #include <linux/compat.h> |
| 822 | |
| 823 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, |
| 824 | compat_ulong_t addr, compat_ulong_t data) |
| 825 | { |
| 826 | compat_ulong_t __user *datap = compat_ptr(data); |
| 827 | compat_ulong_t word; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 828 | siginfo_t siginfo; |
Roland McGrath | 032d82d | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 829 | int ret; |
| 830 | |
| 831 | switch (request) { |
| 832 | case PTRACE_PEEKTEXT: |
| 833 | case PTRACE_PEEKDATA: |
| 834 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); |
| 835 | if (ret != sizeof(word)) |
| 836 | ret = -EIO; |
| 837 | else |
| 838 | ret = put_user(word, datap); |
| 839 | break; |
| 840 | |
| 841 | case PTRACE_POKETEXT: |
| 842 | case PTRACE_POKEDATA: |
| 843 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); |
| 844 | ret = (ret != sizeof(data) ? -EIO : 0); |
| 845 | break; |
| 846 | |
| 847 | case PTRACE_GETEVENTMSG: |
| 848 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); |
| 849 | break; |
| 850 | |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 851 | case PTRACE_GETSIGINFO: |
| 852 | ret = ptrace_getsiginfo(child, &siginfo); |
| 853 | if (!ret) |
| 854 | ret = copy_siginfo_to_user32( |
| 855 | (struct compat_siginfo __user *) datap, |
| 856 | &siginfo); |
| 857 | break; |
| 858 | |
| 859 | case PTRACE_SETSIGINFO: |
| 860 | memset(&siginfo, 0, sizeof siginfo); |
| 861 | if (copy_siginfo_from_user32( |
| 862 | &siginfo, (struct compat_siginfo __user *) datap)) |
| 863 | ret = -EFAULT; |
| 864 | else |
| 865 | ret = ptrace_setsiginfo(child, &siginfo); |
| 866 | break; |
Suresh Siddha | 2225a12 | 2010-02-11 11:51:00 -0800 | [diff] [blame] | 867 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
| 868 | case PTRACE_GETREGSET: |
| 869 | case PTRACE_SETREGSET: |
| 870 | { |
| 871 | struct iovec kiov; |
| 872 | struct compat_iovec __user *uiov = |
| 873 | (struct compat_iovec __user *) datap; |
| 874 | compat_uptr_t ptr; |
| 875 | compat_size_t len; |
| 876 | |
| 877 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) |
| 878 | return -EFAULT; |
| 879 | |
| 880 | if (__get_user(ptr, &uiov->iov_base) || |
| 881 | __get_user(len, &uiov->iov_len)) |
| 882 | return -EFAULT; |
| 883 | |
| 884 | kiov.iov_base = compat_ptr(ptr); |
| 885 | kiov.iov_len = len; |
| 886 | |
| 887 | ret = ptrace_regset(child, request, addr, &kiov); |
| 888 | if (!ret) |
| 889 | ret = __put_user(kiov.iov_len, &uiov->iov_len); |
| 890 | break; |
| 891 | } |
| 892 | #endif |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 893 | |
Roland McGrath | 032d82d | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 894 | default: |
| 895 | ret = ptrace_request(child, request, addr, data); |
| 896 | } |
| 897 | |
| 898 | return ret; |
| 899 | } |
Roland McGrath | c269f19 | 2008-01-30 13:31:48 +0100 | [diff] [blame] | 900 | |
Roland McGrath | c269f19 | 2008-01-30 13:31:48 +0100 | [diff] [blame] | 901 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, |
| 902 | compat_long_t addr, compat_long_t data) |
| 903 | { |
| 904 | struct task_struct *child; |
| 905 | long ret; |
| 906 | |
Roland McGrath | c269f19 | 2008-01-30 13:31:48 +0100 | [diff] [blame] | 907 | if (request == PTRACE_TRACEME) { |
| 908 | ret = ptrace_traceme(); |
| 909 | goto out; |
| 910 | } |
| 911 | |
| 912 | child = ptrace_get_task_struct(pid); |
| 913 | if (IS_ERR(child)) { |
| 914 | ret = PTR_ERR(child); |
| 915 | goto out; |
| 916 | } |
| 917 | |
| 918 | if (request == PTRACE_ATTACH) { |
| 919 | ret = ptrace_attach(child); |
| 920 | /* |
| 921 | * Some architectures need to do book-keeping after |
| 922 | * a ptrace attach. |
| 923 | */ |
| 924 | if (!ret) |
| 925 | arch_ptrace_attach(child); |
| 926 | goto out_put_task_struct; |
| 927 | } |
| 928 | |
| 929 | ret = ptrace_check_attach(child, request == PTRACE_KILL); |
| 930 | if (!ret) |
| 931 | ret = compat_arch_ptrace(child, request, addr, data); |
| 932 | |
| 933 | out_put_task_struct: |
| 934 | put_task_struct(child); |
| 935 | out: |
Roland McGrath | c269f19 | 2008-01-30 13:31:48 +0100 | [diff] [blame] | 936 | return ret; |
| 937 | } |
Christoph Hellwig | 96b8936 | 2008-11-25 08:10:03 +0100 | [diff] [blame] | 938 | #endif /* CONFIG_COMPAT */ |
Frederic Weisbecker | bf26c01 | 2011-04-07 16:53:20 +0200 | [diff] [blame] | 939 | |
| 940 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
| 941 | int ptrace_get_breakpoints(struct task_struct *tsk) |
| 942 | { |
| 943 | if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) |
| 944 | return 0; |
| 945 | |
| 946 | return -1; |
| 947 | } |
| 948 | |
| 949 | void ptrace_put_breakpoints(struct task_struct *tsk) |
| 950 | { |
| 951 | if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) |
| 952 | flush_ptrace_hw_breakpoint(tsk); |
| 953 | } |
| 954 | #endif /* CONFIG_HAVE_HW_BREAKPOINT */ |