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> |
| 17 | #include <linux/smp_lock.h> |
| 18 | #include <linux/ptrace.h> |
| 19 | #include <linux/security.h> |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 20 | #include <linux/signal.h> |
Al Viro | a5cb013 | 2007-03-20 13:58:35 -0400 | [diff] [blame] | 21 | #include <linux/audit.h> |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 22 | #include <linux/pid_namespace.h> |
Adrian Bunk | f17d30a | 2008-02-06 01:36:44 -0800 | [diff] [blame] | 23 | #include <linux/syscalls.h> |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 24 | #include <linux/uaccess.h> |
Suresh Siddha | 2225a12 | 2010-02-11 11:51:00 -0800 | [diff] [blame] | 25 | #include <linux/regset.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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | /* |
| 42 | * Turn a tracing stop into a normal stop now, since with no tracer there |
| 43 | * would be no way to wake it up with SIGCONT or SIGKILL. If there was a |
| 44 | * signal sent that would resume the child, but didn't because it was in |
| 45 | * TASK_TRACED, resume it now. |
| 46 | * Requires that irqs be disabled. |
| 47 | */ |
Adrian Bunk | b747c8c | 2008-10-18 20:28:21 -0700 | [diff] [blame] | 48 | static void ptrace_untrace(struct task_struct *child) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | { |
| 50 | spin_lock(&child->sighand->siglock); |
Matthew Wilcox | 6618a3e | 2007-12-06 11:06:16 -0500 | [diff] [blame] | 51 | if (task_is_traced(child)) { |
Oleg Nesterov | 1ee1184 | 2009-04-02 16:58:23 -0700 | [diff] [blame] | 52 | /* |
| 53 | * If the group stop is completed or in progress, |
| 54 | * this thread was already counted as stopped. |
| 55 | */ |
| 56 | if (child->signal->flags & SIGNAL_STOP_STOPPED || |
| 57 | child->signal->group_stop_count) |
Oleg Nesterov | d9ae90a | 2008-02-06 01:36:13 -0800 | [diff] [blame] | 58 | __set_task_state(child, TASK_STOPPED); |
Oleg Nesterov | 1ee1184 | 2009-04-02 16:58:23 -0700 | [diff] [blame] | 59 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | signal_wake_up(child, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | } |
| 62 | spin_unlock(&child->sighand->siglock); |
| 63 | } |
| 64 | |
| 65 | /* |
| 66 | * unptrace a task: move it back to its original parent and |
| 67 | * remove it from the ptrace list. |
| 68 | * |
| 69 | * Must be called with the tasklist lock write-held. |
| 70 | */ |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 71 | void __ptrace_unlink(struct task_struct *child) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | { |
Oleg Nesterov | 5ecfbae | 2006-02-15 22:50:10 +0300 | [diff] [blame] | 73 | BUG_ON(!child->ptrace); |
| 74 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | child->ptrace = 0; |
Roland McGrath | f470021 | 2008-03-24 18:36:23 -0700 | [diff] [blame] | 76 | child->parent = child->real_parent; |
| 77 | list_del_init(&child->ptrace_entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | |
Markus Metzger | bf53de9 | 2008-12-19 15:10:24 +0100 | [diff] [blame] | 79 | arch_ptrace_untrace(child); |
Matthew Wilcox | 6618a3e | 2007-12-06 11:06:16 -0500 | [diff] [blame] | 80 | if (task_is_traced(child)) |
Roland McGrath | e57a505 | 2006-04-12 16:30:20 -0700 | [diff] [blame] | 81 | ptrace_untrace(child); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | } |
| 83 | |
| 84 | /* |
| 85 | * Check that we have indeed attached to the thing.. |
| 86 | */ |
| 87 | int ptrace_check_attach(struct task_struct *child, int kill) |
| 88 | { |
| 89 | int ret = -ESRCH; |
| 90 | |
| 91 | /* |
| 92 | * We take the read lock around doing both checks to close a |
| 93 | * possible race where someone else was tracing our child and |
| 94 | * detached between these two checks. After this locked check, |
| 95 | * we are sure that this is our traced child and that can only |
| 96 | * be changed by us so it's not changing right after this. |
| 97 | */ |
| 98 | read_lock(&tasklist_lock); |
Oleg Nesterov | c0c0b64 | 2008-02-08 04:19:00 -0800 | [diff] [blame] | 99 | if ((child->ptrace & PT_PTRACED) && child->parent == current) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | ret = 0; |
Oleg Nesterov | c0c0b64 | 2008-02-08 04:19:00 -0800 | [diff] [blame] | 101 | /* |
| 102 | * child->sighand can't be NULL, release_task() |
| 103 | * does ptrace_unlink() before __exit_signal(). |
| 104 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | spin_lock_irq(&child->sighand->siglock); |
Oleg Nesterov | d9ae90a | 2008-02-06 01:36:13 -0800 | [diff] [blame] | 106 | if (task_is_stopped(child)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | child->state = TASK_TRACED; |
Oleg Nesterov | d9ae90a | 2008-02-06 01:36:13 -0800 | [diff] [blame] | 108 | else if (!task_is_traced(child) && !kill) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | ret = -ESRCH; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | spin_unlock_irq(&child->sighand->siglock); |
| 111 | } |
| 112 | read_unlock(&tasklist_lock); |
| 113 | |
Oleg Nesterov | d9ae90a | 2008-02-06 01:36:13 -0800 | [diff] [blame] | 114 | if (!ret && !kill) |
Roland McGrath | 85ba2d8 | 2008-07-25 19:45:58 -0700 | [diff] [blame] | 115 | ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | |
| 117 | /* All systems go.. */ |
| 118 | return ret; |
| 119 | } |
| 120 | |
Stephen Smalley | 006ebb4 | 2008-05-19 08:32:49 -0400 | [diff] [blame] | 121 | int __ptrace_may_access(struct task_struct *task, unsigned int mode) |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 122 | { |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 123 | const struct cred *cred = current_cred(), *tcred; |
David Howells | b6dff3e | 2008-11-14 10:39:16 +1100 | [diff] [blame] | 124 | |
Eric W. Biederman | df26c40 | 2006-06-26 00:25:59 -0700 | [diff] [blame] | 125 | /* May we inspect the given task? |
| 126 | * This check is used both for attaching with ptrace |
| 127 | * and for allowing access to sensitive information in /proc. |
| 128 | * |
| 129 | * ptrace_attach denies several cases that /proc allows |
| 130 | * because setting up the necessary parent/child relationship |
| 131 | * or halting the specified task is impossible. |
| 132 | */ |
| 133 | int dumpable = 0; |
| 134 | /* Don't let security modules deny introspection */ |
| 135 | if (task == current) |
| 136 | return 0; |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 137 | rcu_read_lock(); |
| 138 | tcred = __task_cred(task); |
| 139 | if ((cred->uid != tcred->euid || |
| 140 | cred->uid != tcred->suid || |
| 141 | cred->uid != tcred->uid || |
| 142 | cred->gid != tcred->egid || |
| 143 | cred->gid != tcred->sgid || |
| 144 | cred->gid != tcred->gid) && |
| 145 | !capable(CAP_SYS_PTRACE)) { |
| 146 | rcu_read_unlock(); |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 147 | return -EPERM; |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 148 | } |
| 149 | rcu_read_unlock(); |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 150 | smp_rmb(); |
Eric W. Biederman | df26c40 | 2006-06-26 00:25:59 -0700 | [diff] [blame] | 151 | if (task->mm) |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 152 | dumpable = get_dumpable(task->mm); |
Eric W. Biederman | df26c40 | 2006-06-26 00:25:59 -0700 | [diff] [blame] | 153 | if (!dumpable && !capable(CAP_SYS_PTRACE)) |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 154 | return -EPERM; |
| 155 | |
Ingo Molnar | 9e48858 | 2009-05-07 19:26:19 +1000 | [diff] [blame] | 156 | return security_ptrace_access_check(task, mode); |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 157 | } |
| 158 | |
Stephen Smalley | 006ebb4 | 2008-05-19 08:32:49 -0400 | [diff] [blame] | 159 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 160 | { |
| 161 | int err; |
| 162 | task_lock(task); |
Stephen Smalley | 006ebb4 | 2008-05-19 08:32:49 -0400 | [diff] [blame] | 163 | err = __ptrace_may_access(task, mode); |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 164 | task_unlock(task); |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 165 | return !err; |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 166 | } |
| 167 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | int ptrace_attach(struct task_struct *task) |
| 169 | { |
| 170 | int retval; |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 171 | |
Al Viro | a5cb013 | 2007-03-20 13:58:35 -0400 | [diff] [blame] | 172 | audit_ptrace(task); |
| 173 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | retval = -EPERM; |
Oleg Nesterov | b79b7ba | 2009-06-17 16:27:31 -0700 | [diff] [blame] | 175 | if (unlikely(task->flags & PF_KTHREAD)) |
| 176 | goto out; |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 177 | if (same_thread_group(task, current)) |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 178 | goto out; |
| 179 | |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 180 | /* |
| 181 | * Protect exec's credential calculations against our interference; |
David Howells | 5e751e9 | 2009-05-08 13:55:22 +0100 | [diff] [blame] | 182 | * interference; SUID, SGID and LSM creds get determined differently |
| 183 | * under ptrace. |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 184 | */ |
Oleg Nesterov | 793285f | 2009-07-05 12:08:26 -0700 | [diff] [blame] | 185 | retval = -ERESTARTNOINTR; |
| 186 | if (mutex_lock_interruptible(&task->cred_guard_mutex)) |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 187 | goto out; |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 188 | |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 189 | task_lock(task); |
Stephen Smalley | 006ebb4 | 2008-05-19 08:32:49 -0400 | [diff] [blame] | 190 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 191 | task_unlock(task); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | if (retval) |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 193 | goto unlock_creds; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 195 | write_lock_irq(&tasklist_lock); |
Oleg Nesterov | b79b7ba | 2009-06-17 16:27:31 -0700 | [diff] [blame] | 196 | retval = -EPERM; |
| 197 | if (unlikely(task->exit_state)) |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 198 | goto unlock_tasklist; |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 199 | if (task->ptrace) |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 200 | goto unlock_tasklist; |
Oleg Nesterov | b79b7ba | 2009-06-17 16:27:31 -0700 | [diff] [blame] | 201 | |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 202 | task->ptrace = PT_PTRACED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | if (capable(CAP_SYS_PTRACE)) |
| 204 | task->ptrace |= PT_PTRACE_CAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | __ptrace_link(task, current); |
Oleg Nesterov | 33e9fc7 | 2008-04-30 00:53:14 -0700 | [diff] [blame] | 207 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); |
Oleg Nesterov | b79b7ba | 2009-06-17 16:27:31 -0700 | [diff] [blame] | 208 | |
| 209 | retval = 0; |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 210 | unlock_tasklist: |
| 211 | write_unlock_irq(&tasklist_lock); |
| 212 | unlock_creds: |
David Howells | 5e751e9 | 2009-05-08 13:55:22 +0100 | [diff] [blame] | 213 | mutex_unlock(&task->cred_guard_mutex); |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 214 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | return retval; |
| 216 | } |
| 217 | |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 218 | /** |
| 219 | * ptrace_traceme -- helper for PTRACE_TRACEME |
| 220 | * |
| 221 | * Performs checks and sets PT_PTRACED. |
| 222 | * Should be used by all ptrace implementations for PTRACE_TRACEME. |
| 223 | */ |
| 224 | int ptrace_traceme(void) |
| 225 | { |
| 226 | int ret = -EPERM; |
| 227 | |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 228 | write_lock_irq(&tasklist_lock); |
| 229 | /* Are we already being traced? */ |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 230 | if (!current->ptrace) { |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 231 | ret = security_ptrace_traceme(current->parent); |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 232 | /* |
| 233 | * Check PF_EXITING to ensure ->real_parent has not passed |
| 234 | * exit_ptrace(). Otherwise we don't report the error but |
| 235 | * pretend ->real_parent untraces us right after return. |
| 236 | */ |
| 237 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { |
| 238 | current->ptrace = PT_PTRACED; |
| 239 | __ptrace_link(current, current->real_parent); |
| 240 | } |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 241 | } |
Oleg Nesterov | 4b105cb | 2009-06-17 16:27:33 -0700 | [diff] [blame] | 242 | write_unlock_irq(&tasklist_lock); |
| 243 | |
Oleg Nesterov | f2f0b00 | 2009-06-17 16:27:32 -0700 | [diff] [blame] | 244 | return ret; |
| 245 | } |
| 246 | |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 247 | /* |
| 248 | * Called with irqs disabled, returns true if childs should reap themselves. |
| 249 | */ |
| 250 | static int ignoring_children(struct sighand_struct *sigh) |
| 251 | { |
| 252 | int ret; |
| 253 | spin_lock(&sigh->siglock); |
| 254 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || |
| 255 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); |
| 256 | spin_unlock(&sigh->siglock); |
| 257 | return ret; |
| 258 | } |
| 259 | |
| 260 | /* |
| 261 | * Called with tasklist_lock held for writing. |
| 262 | * Unlink a traced task, and clean it up if it was a traced zombie. |
| 263 | * Return true if it needs to be reaped with release_task(). |
| 264 | * (We can't call release_task() here because we already hold tasklist_lock.) |
| 265 | * |
| 266 | * If it's a zombie, our attachedness prevented normal parent notification |
| 267 | * or self-reaping. Do notification now if it would have happened earlier. |
| 268 | * If it should reap itself, return true. |
| 269 | * |
Oleg Nesterov | a7f0765 | 2009-09-23 15:56:44 -0700 | [diff] [blame] | 270 | * If it's our own child, there is no notification to do. But if our normal |
| 271 | * children self-reap, then this child was prevented by ptrace and we must |
| 272 | * reap it now, in that case we must also wake up sub-threads sleeping in |
| 273 | * do_wait(). |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 274 | */ |
| 275 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) |
| 276 | { |
| 277 | __ptrace_unlink(p); |
| 278 | |
| 279 | if (p->exit_state == EXIT_ZOMBIE) { |
| 280 | if (!task_detached(p) && thread_group_empty(p)) { |
| 281 | if (!same_thread_group(p->real_parent, tracer)) |
| 282 | do_notify_parent(p, p->exit_signal); |
Oleg Nesterov | a7f0765 | 2009-09-23 15:56:44 -0700 | [diff] [blame] | 283 | else if (ignoring_children(tracer->sighand)) { |
| 284 | __wake_up_parent(p, tracer); |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 285 | p->exit_signal = -1; |
Oleg Nesterov | a7f0765 | 2009-09-23 15:56:44 -0700 | [diff] [blame] | 286 | } |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 287 | } |
| 288 | if (task_detached(p)) { |
| 289 | /* Mark it as in the process of being reaped. */ |
| 290 | p->exit_state = EXIT_DEAD; |
| 291 | return true; |
| 292 | } |
| 293 | } |
| 294 | |
| 295 | return false; |
| 296 | } |
| 297 | |
Oleg Nesterov | 5ecfbae | 2006-02-15 22:50:10 +0300 | [diff] [blame] | 298 | int ptrace_detach(struct task_struct *child, unsigned int data) |
| 299 | { |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 300 | bool dead = false; |
Oleg Nesterov | 4576145 | 2009-04-02 16:58:14 -0700 | [diff] [blame] | 301 | |
Oleg Nesterov | 5ecfbae | 2006-02-15 22:50:10 +0300 | [diff] [blame] | 302 | if (!valid_signal(data)) |
| 303 | return -EIO; |
| 304 | |
| 305 | /* Architecture-specific hardware disable .. */ |
| 306 | ptrace_disable(child); |
Roland McGrath | 7d94143 | 2007-09-05 03:05:56 -0700 | [diff] [blame] | 307 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
Oleg Nesterov | 5ecfbae | 2006-02-15 22:50:10 +0300 | [diff] [blame] | 308 | |
Oleg Nesterov | 95c3eb7 | 2009-04-02 16:58:11 -0700 | [diff] [blame] | 309 | write_lock_irq(&tasklist_lock); |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 310 | /* |
| 311 | * This child can be already killed. Make sure de_thread() or |
| 312 | * our sub-thread doing do_wait() didn't do release_task() yet. |
| 313 | */ |
Oleg Nesterov | 95c3eb7 | 2009-04-02 16:58:11 -0700 | [diff] [blame] | 314 | if (child->ptrace) { |
| 315 | child->exit_code = data; |
Oleg Nesterov | 4576145 | 2009-04-02 16:58:14 -0700 | [diff] [blame] | 316 | dead = __ptrace_detach(current, child); |
Oleg Nesterov | edaba2c | 2009-06-04 16:29:09 -0700 | [diff] [blame] | 317 | if (!child->exit_state) |
| 318 | wake_up_process(child); |
Oleg Nesterov | 95c3eb7 | 2009-04-02 16:58:11 -0700 | [diff] [blame] | 319 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | write_unlock_irq(&tasklist_lock); |
| 321 | |
Oleg Nesterov | 4576145 | 2009-04-02 16:58:14 -0700 | [diff] [blame] | 322 | if (unlikely(dead)) |
| 323 | release_task(child); |
| 324 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | return 0; |
| 326 | } |
| 327 | |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 328 | /* |
| 329 | * Detach all tasks we were using ptrace on. |
| 330 | */ |
| 331 | void exit_ptrace(struct task_struct *tracer) |
| 332 | { |
| 333 | struct task_struct *p, *n; |
| 334 | LIST_HEAD(ptrace_dead); |
| 335 | |
| 336 | write_lock_irq(&tasklist_lock); |
| 337 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
| 338 | if (__ptrace_detach(tracer, p)) |
| 339 | list_add(&p->ptrace_entry, &ptrace_dead); |
| 340 | } |
| 341 | write_unlock_irq(&tasklist_lock); |
| 342 | |
| 343 | BUG_ON(!list_empty(&tracer->ptraced)); |
| 344 | |
| 345 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { |
| 346 | list_del_init(&p->ptrace_entry); |
| 347 | release_task(p); |
| 348 | } |
| 349 | } |
| 350 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
| 352 | { |
| 353 | int copied = 0; |
| 354 | |
| 355 | while (len > 0) { |
| 356 | char buf[128]; |
| 357 | int this_len, retval; |
| 358 | |
| 359 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; |
| 360 | retval = access_process_vm(tsk, src, buf, this_len, 0); |
| 361 | if (!retval) { |
| 362 | if (copied) |
| 363 | break; |
| 364 | return -EIO; |
| 365 | } |
| 366 | if (copy_to_user(dst, buf, retval)) |
| 367 | return -EFAULT; |
| 368 | copied += retval; |
| 369 | src += retval; |
| 370 | dst += retval; |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 371 | len -= retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | } |
| 373 | return copied; |
| 374 | } |
| 375 | |
| 376 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) |
| 377 | { |
| 378 | int copied = 0; |
| 379 | |
| 380 | while (len > 0) { |
| 381 | char buf[128]; |
| 382 | int this_len, retval; |
| 383 | |
| 384 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; |
| 385 | if (copy_from_user(buf, src, this_len)) |
| 386 | return -EFAULT; |
| 387 | retval = access_process_vm(tsk, dst, buf, this_len, 1); |
| 388 | if (!retval) { |
| 389 | if (copied) |
| 390 | break; |
| 391 | return -EIO; |
| 392 | } |
| 393 | copied += retval; |
| 394 | src += retval; |
| 395 | dst += retval; |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 396 | len -= retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 397 | } |
| 398 | return copied; |
| 399 | } |
| 400 | |
| 401 | static int ptrace_setoptions(struct task_struct *child, long data) |
| 402 | { |
| 403 | child->ptrace &= ~PT_TRACE_MASK; |
| 404 | |
| 405 | if (data & PTRACE_O_TRACESYSGOOD) |
| 406 | child->ptrace |= PT_TRACESYSGOOD; |
| 407 | |
| 408 | if (data & PTRACE_O_TRACEFORK) |
| 409 | child->ptrace |= PT_TRACE_FORK; |
| 410 | |
| 411 | if (data & PTRACE_O_TRACEVFORK) |
| 412 | child->ptrace |= PT_TRACE_VFORK; |
| 413 | |
| 414 | if (data & PTRACE_O_TRACECLONE) |
| 415 | child->ptrace |= PT_TRACE_CLONE; |
| 416 | |
| 417 | if (data & PTRACE_O_TRACEEXEC) |
| 418 | child->ptrace |= PT_TRACE_EXEC; |
| 419 | |
| 420 | if (data & PTRACE_O_TRACEVFORKDONE) |
| 421 | child->ptrace |= PT_TRACE_VFORK_DONE; |
| 422 | |
| 423 | if (data & PTRACE_O_TRACEEXIT) |
| 424 | child->ptrace |= PT_TRACE_EXIT; |
| 425 | |
| 426 | return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; |
| 427 | } |
| 428 | |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 429 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | { |
Oleg Nesterov | e496125 | 2009-06-17 16:27:36 -0700 | [diff] [blame] | 431 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | int error = -ESRCH; |
| 433 | |
Oleg Nesterov | e496125 | 2009-06-17 16:27:36 -0700 | [diff] [blame] | 434 | if (lock_task_sighand(child, &flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | error = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | if (likely(child->last_siginfo != NULL)) { |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 437 | *info = *child->last_siginfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | error = 0; |
| 439 | } |
Oleg Nesterov | e496125 | 2009-06-17 16:27:36 -0700 | [diff] [blame] | 440 | unlock_task_sighand(child, &flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | return error; |
| 443 | } |
| 444 | |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 445 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | { |
Oleg Nesterov | e496125 | 2009-06-17 16:27:36 -0700 | [diff] [blame] | 447 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | int error = -ESRCH; |
| 449 | |
Oleg Nesterov | e496125 | 2009-06-17 16:27:36 -0700 | [diff] [blame] | 450 | if (lock_task_sighand(child, &flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | error = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | if (likely(child->last_siginfo != NULL)) { |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 453 | *child->last_siginfo = *info; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | error = 0; |
| 455 | } |
Oleg Nesterov | e496125 | 2009-06-17 16:27:36 -0700 | [diff] [blame] | 456 | unlock_task_sighand(child, &flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 457 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | return error; |
| 459 | } |
| 460 | |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 461 | |
| 462 | #ifdef PTRACE_SINGLESTEP |
| 463 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) |
| 464 | #else |
| 465 | #define is_singlestep(request) 0 |
| 466 | #endif |
| 467 | |
Roland McGrath | 5b88abb | 2008-01-30 13:30:53 +0100 | [diff] [blame] | 468 | #ifdef PTRACE_SINGLEBLOCK |
| 469 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) |
| 470 | #else |
| 471 | #define is_singleblock(request) 0 |
| 472 | #endif |
| 473 | |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 474 | #ifdef PTRACE_SYSEMU |
| 475 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) |
| 476 | #else |
| 477 | #define is_sysemu_singlestep(request) 0 |
| 478 | #endif |
| 479 | |
| 480 | static int ptrace_resume(struct task_struct *child, long request, long data) |
| 481 | { |
| 482 | if (!valid_signal(data)) |
| 483 | return -EIO; |
| 484 | |
| 485 | if (request == PTRACE_SYSCALL) |
| 486 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 487 | else |
| 488 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 489 | |
| 490 | #ifdef TIF_SYSCALL_EMU |
| 491 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) |
| 492 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); |
| 493 | else |
| 494 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); |
| 495 | #endif |
| 496 | |
Roland McGrath | 5b88abb | 2008-01-30 13:30:53 +0100 | [diff] [blame] | 497 | if (is_singleblock(request)) { |
| 498 | if (unlikely(!arch_has_block_step())) |
| 499 | return -EIO; |
| 500 | user_enable_block_step(child); |
| 501 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 502 | if (unlikely(!arch_has_single_step())) |
| 503 | return -EIO; |
| 504 | user_enable_single_step(child); |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 505 | } else { |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 506 | user_disable_single_step(child); |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 507 | } |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 508 | |
| 509 | child->exit_code = data; |
| 510 | wake_up_process(child); |
| 511 | |
| 512 | return 0; |
| 513 | } |
| 514 | |
Suresh Siddha | 2225a12 | 2010-02-11 11:51:00 -0800 | [diff] [blame] | 515 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
| 516 | |
| 517 | static const struct user_regset * |
| 518 | find_regset(const struct user_regset_view *view, unsigned int type) |
| 519 | { |
| 520 | const struct user_regset *regset; |
| 521 | int n; |
| 522 | |
| 523 | for (n = 0; n < view->n; ++n) { |
| 524 | regset = view->regsets + n; |
| 525 | if (regset->core_note_type == type) |
| 526 | return regset; |
| 527 | } |
| 528 | |
| 529 | return NULL; |
| 530 | } |
| 531 | |
| 532 | static int ptrace_regset(struct task_struct *task, int req, unsigned int type, |
| 533 | struct iovec *kiov) |
| 534 | { |
| 535 | const struct user_regset_view *view = task_user_regset_view(task); |
| 536 | const struct user_regset *regset = find_regset(view, type); |
| 537 | int regset_no; |
| 538 | |
| 539 | if (!regset || (kiov->iov_len % regset->size) != 0) |
Suresh Siddha | c6a0dd7 | 2010-02-22 14:51:32 -0800 | [diff] [blame] | 540 | return -EINVAL; |
Suresh Siddha | 2225a12 | 2010-02-11 11:51:00 -0800 | [diff] [blame] | 541 | |
| 542 | regset_no = regset - view->regsets; |
| 543 | kiov->iov_len = min(kiov->iov_len, |
| 544 | (__kernel_size_t) (regset->n * regset->size)); |
| 545 | |
| 546 | if (req == PTRACE_GETREGSET) |
| 547 | return copy_regset_to_user(task, view, regset_no, 0, |
| 548 | kiov->iov_len, kiov->iov_base); |
| 549 | else |
| 550 | return copy_regset_from_user(task, view, regset_no, 0, |
| 551 | kiov->iov_len, kiov->iov_base); |
| 552 | } |
| 553 | |
| 554 | #endif |
| 555 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | int ptrace_request(struct task_struct *child, long request, |
| 557 | long addr, long data) |
| 558 | { |
| 559 | int ret = -EIO; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 560 | siginfo_t siginfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 561 | |
| 562 | switch (request) { |
Roland McGrath | 16c3e38 | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 563 | case PTRACE_PEEKTEXT: |
| 564 | case PTRACE_PEEKDATA: |
| 565 | return generic_ptrace_peekdata(child, addr, data); |
| 566 | case PTRACE_POKETEXT: |
| 567 | case PTRACE_POKEDATA: |
| 568 | return generic_ptrace_pokedata(child, addr, data); |
| 569 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | #ifdef PTRACE_OLDSETOPTIONS |
| 571 | case PTRACE_OLDSETOPTIONS: |
| 572 | #endif |
| 573 | case PTRACE_SETOPTIONS: |
| 574 | ret = ptrace_setoptions(child, data); |
| 575 | break; |
| 576 | case PTRACE_GETEVENTMSG: |
| 577 | ret = put_user(child->ptrace_message, (unsigned long __user *) data); |
| 578 | break; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 579 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 580 | case PTRACE_GETSIGINFO: |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 581 | ret = ptrace_getsiginfo(child, &siginfo); |
| 582 | if (!ret) |
| 583 | ret = copy_siginfo_to_user((siginfo_t __user *) data, |
| 584 | &siginfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | break; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 586 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | case PTRACE_SETSIGINFO: |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 588 | if (copy_from_user(&siginfo, (siginfo_t __user *) data, |
| 589 | sizeof siginfo)) |
| 590 | ret = -EFAULT; |
| 591 | else |
| 592 | ret = ptrace_setsiginfo(child, &siginfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | break; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 594 | |
Alexey Dobriyan | 1bcf548 | 2007-10-16 01:23:45 -0700 | [diff] [blame] | 595 | case PTRACE_DETACH: /* detach a process that was attached. */ |
| 596 | ret = ptrace_detach(child, data); |
| 597 | break; |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 598 | |
| 599 | #ifdef PTRACE_SINGLESTEP |
| 600 | case PTRACE_SINGLESTEP: |
| 601 | #endif |
Roland McGrath | 5b88abb | 2008-01-30 13:30:53 +0100 | [diff] [blame] | 602 | #ifdef PTRACE_SINGLEBLOCK |
| 603 | case PTRACE_SINGLEBLOCK: |
| 604 | #endif |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 605 | #ifdef PTRACE_SYSEMU |
| 606 | case PTRACE_SYSEMU: |
| 607 | case PTRACE_SYSEMU_SINGLESTEP: |
| 608 | #endif |
| 609 | case PTRACE_SYSCALL: |
| 610 | case PTRACE_CONT: |
| 611 | return ptrace_resume(child, request, data); |
| 612 | |
| 613 | case PTRACE_KILL: |
| 614 | if (child->exit_state) /* already dead */ |
| 615 | return 0; |
| 616 | return ptrace_resume(child, request, SIGKILL); |
| 617 | |
Suresh Siddha | 2225a12 | 2010-02-11 11:51:00 -0800 | [diff] [blame] | 618 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
| 619 | case PTRACE_GETREGSET: |
| 620 | case PTRACE_SETREGSET: |
| 621 | { |
| 622 | struct iovec kiov; |
| 623 | struct iovec __user *uiov = (struct iovec __user *) data; |
| 624 | |
| 625 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) |
| 626 | return -EFAULT; |
| 627 | |
| 628 | if (__get_user(kiov.iov_base, &uiov->iov_base) || |
| 629 | __get_user(kiov.iov_len, &uiov->iov_len)) |
| 630 | return -EFAULT; |
| 631 | |
| 632 | ret = ptrace_regset(child, request, addr, &kiov); |
| 633 | if (!ret) |
| 634 | ret = __put_user(kiov.iov_len, &uiov->iov_len); |
| 635 | break; |
| 636 | } |
| 637 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 638 | default: |
| 639 | break; |
| 640 | } |
| 641 | |
| 642 | return ret; |
| 643 | } |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 644 | |
Oleg Nesterov | 8053bdd | 2009-06-17 16:27:34 -0700 | [diff] [blame] | 645 | static struct task_struct *ptrace_get_task_struct(pid_t pid) |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 646 | { |
| 647 | struct task_struct *child; |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 648 | |
Oleg Nesterov | 8053bdd | 2009-06-17 16:27:34 -0700 | [diff] [blame] | 649 | rcu_read_lock(); |
Pavel Emelyanov | 228ebcb | 2007-10-18 23:40:16 -0700 | [diff] [blame] | 650 | child = find_task_by_vpid(pid); |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 651 | if (child) |
| 652 | get_task_struct(child); |
Oleg Nesterov | 8053bdd | 2009-06-17 16:27:34 -0700 | [diff] [blame] | 653 | rcu_read_unlock(); |
Sukadev Bhattiprolu | f400e19 | 2006-09-29 02:00:07 -0700 | [diff] [blame] | 654 | |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 655 | if (!child) |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 656 | return ERR_PTR(-ESRCH); |
| 657 | return child; |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 658 | } |
| 659 | |
Christoph Hellwig | 0ac1555 | 2007-10-16 01:26:37 -0700 | [diff] [blame] | 660 | #ifndef arch_ptrace_attach |
| 661 | #define arch_ptrace_attach(child) do { } while (0) |
| 662 | #endif |
| 663 | |
Heiko Carstens | 1e7bfb2 | 2009-01-14 14:14:29 +0100 | [diff] [blame] | 664 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, long, addr, long, data) |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 665 | { |
| 666 | struct task_struct *child; |
| 667 | long ret; |
| 668 | |
| 669 | /* |
| 670 | * This lock_kernel fixes a subtle race with suid exec |
| 671 | */ |
| 672 | lock_kernel(); |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 673 | if (request == PTRACE_TRACEME) { |
| 674 | ret = ptrace_traceme(); |
Haavard Skinnemoen | 6ea6dd9 | 2007-11-27 13:02:40 +0100 | [diff] [blame] | 675 | if (!ret) |
| 676 | arch_ptrace_attach(current); |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 677 | goto out; |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 678 | } |
| 679 | |
| 680 | child = ptrace_get_task_struct(pid); |
| 681 | if (IS_ERR(child)) { |
| 682 | ret = PTR_ERR(child); |
| 683 | goto out; |
| 684 | } |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 685 | |
| 686 | if (request == PTRACE_ATTACH) { |
| 687 | ret = ptrace_attach(child); |
Christoph Hellwig | 0ac1555 | 2007-10-16 01:26:37 -0700 | [diff] [blame] | 688 | /* |
| 689 | * Some architectures need to do book-keeping after |
| 690 | * a ptrace attach. |
| 691 | */ |
| 692 | if (!ret) |
| 693 | arch_ptrace_attach(child); |
Christoph Hellwig | 005f18d | 2005-11-13 16:06:33 -0800 | [diff] [blame] | 694 | goto out_put_task_struct; |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 695 | } |
| 696 | |
| 697 | ret = ptrace_check_attach(child, request == PTRACE_KILL); |
| 698 | if (ret < 0) |
| 699 | goto out_put_task_struct; |
| 700 | |
| 701 | ret = arch_ptrace(child, request, addr, data); |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 702 | |
| 703 | out_put_task_struct: |
| 704 | put_task_struct(child); |
| 705 | out: |
| 706 | unlock_kernel(); |
| 707 | return ret; |
| 708 | } |
Alexey Dobriyan | 7664732 | 2007-07-17 04:03:43 -0700 | [diff] [blame] | 709 | |
| 710 | int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data) |
| 711 | { |
| 712 | unsigned long tmp; |
| 713 | int copied; |
| 714 | |
| 715 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); |
| 716 | if (copied != sizeof(tmp)) |
| 717 | return -EIO; |
| 718 | return put_user(tmp, (unsigned long __user *)data); |
| 719 | } |
Alexey Dobriyan | f284ce7 | 2007-07-17 04:03:44 -0700 | [diff] [blame] | 720 | |
| 721 | int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data) |
| 722 | { |
| 723 | int copied; |
| 724 | |
| 725 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); |
| 726 | return (copied == sizeof(data)) ? 0 : -EIO; |
| 727 | } |
Roland McGrath | 032d82d | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 728 | |
Christoph Hellwig | 96b8936 | 2008-11-25 08:10:03 +0100 | [diff] [blame] | 729 | #if defined CONFIG_COMPAT |
Roland McGrath | 032d82d | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 730 | #include <linux/compat.h> |
| 731 | |
| 732 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, |
| 733 | compat_ulong_t addr, compat_ulong_t data) |
| 734 | { |
| 735 | compat_ulong_t __user *datap = compat_ptr(data); |
| 736 | compat_ulong_t word; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 737 | siginfo_t siginfo; |
Roland McGrath | 032d82d | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 738 | int ret; |
| 739 | |
| 740 | switch (request) { |
| 741 | case PTRACE_PEEKTEXT: |
| 742 | case PTRACE_PEEKDATA: |
| 743 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); |
| 744 | if (ret != sizeof(word)) |
| 745 | ret = -EIO; |
| 746 | else |
| 747 | ret = put_user(word, datap); |
| 748 | break; |
| 749 | |
| 750 | case PTRACE_POKETEXT: |
| 751 | case PTRACE_POKEDATA: |
| 752 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); |
| 753 | ret = (ret != sizeof(data) ? -EIO : 0); |
| 754 | break; |
| 755 | |
| 756 | case PTRACE_GETEVENTMSG: |
| 757 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); |
| 758 | break; |
| 759 | |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 760 | case PTRACE_GETSIGINFO: |
| 761 | ret = ptrace_getsiginfo(child, &siginfo); |
| 762 | if (!ret) |
| 763 | ret = copy_siginfo_to_user32( |
| 764 | (struct compat_siginfo __user *) datap, |
| 765 | &siginfo); |
| 766 | break; |
| 767 | |
| 768 | case PTRACE_SETSIGINFO: |
| 769 | memset(&siginfo, 0, sizeof siginfo); |
| 770 | if (copy_siginfo_from_user32( |
| 771 | &siginfo, (struct compat_siginfo __user *) datap)) |
| 772 | ret = -EFAULT; |
| 773 | else |
| 774 | ret = ptrace_setsiginfo(child, &siginfo); |
| 775 | break; |
Suresh Siddha | 2225a12 | 2010-02-11 11:51:00 -0800 | [diff] [blame] | 776 | #ifdef CONFIG_HAVE_ARCH_TRACEHOOK |
| 777 | case PTRACE_GETREGSET: |
| 778 | case PTRACE_SETREGSET: |
| 779 | { |
| 780 | struct iovec kiov; |
| 781 | struct compat_iovec __user *uiov = |
| 782 | (struct compat_iovec __user *) datap; |
| 783 | compat_uptr_t ptr; |
| 784 | compat_size_t len; |
| 785 | |
| 786 | if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) |
| 787 | return -EFAULT; |
| 788 | |
| 789 | if (__get_user(ptr, &uiov->iov_base) || |
| 790 | __get_user(len, &uiov->iov_len)) |
| 791 | return -EFAULT; |
| 792 | |
| 793 | kiov.iov_base = compat_ptr(ptr); |
| 794 | kiov.iov_len = len; |
| 795 | |
| 796 | ret = ptrace_regset(child, request, addr, &kiov); |
| 797 | if (!ret) |
| 798 | ret = __put_user(kiov.iov_len, &uiov->iov_len); |
| 799 | break; |
| 800 | } |
| 801 | #endif |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 802 | |
Roland McGrath | 032d82d | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 803 | default: |
| 804 | ret = ptrace_request(child, request, addr, data); |
| 805 | } |
| 806 | |
| 807 | return ret; |
| 808 | } |
Roland McGrath | c269f19 | 2008-01-30 13:31:48 +0100 | [diff] [blame] | 809 | |
Roland McGrath | c269f19 | 2008-01-30 13:31:48 +0100 | [diff] [blame] | 810 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, |
| 811 | compat_long_t addr, compat_long_t data) |
| 812 | { |
| 813 | struct task_struct *child; |
| 814 | long ret; |
| 815 | |
| 816 | /* |
| 817 | * This lock_kernel fixes a subtle race with suid exec |
| 818 | */ |
| 819 | lock_kernel(); |
| 820 | if (request == PTRACE_TRACEME) { |
| 821 | ret = ptrace_traceme(); |
| 822 | goto out; |
| 823 | } |
| 824 | |
| 825 | child = ptrace_get_task_struct(pid); |
| 826 | if (IS_ERR(child)) { |
| 827 | ret = PTR_ERR(child); |
| 828 | goto out; |
| 829 | } |
| 830 | |
| 831 | if (request == PTRACE_ATTACH) { |
| 832 | ret = ptrace_attach(child); |
| 833 | /* |
| 834 | * Some architectures need to do book-keeping after |
| 835 | * a ptrace attach. |
| 836 | */ |
| 837 | if (!ret) |
| 838 | arch_ptrace_attach(child); |
| 839 | goto out_put_task_struct; |
| 840 | } |
| 841 | |
| 842 | ret = ptrace_check_attach(child, request == PTRACE_KILL); |
| 843 | if (!ret) |
| 844 | ret = compat_arch_ptrace(child, request, addr, data); |
| 845 | |
| 846 | out_put_task_struct: |
| 847 | put_task_struct(child); |
| 848 | out: |
| 849 | unlock_kernel(); |
| 850 | return ret; |
| 851 | } |
Christoph Hellwig | 96b8936 | 2008-11-25 08:10:03 +0100 | [diff] [blame] | 852 | #endif /* CONFIG_COMPAT */ |