Release 4.15 kernel/ptrace.c

/*
 * linux/kernel/ptrace.c
 *
 * (C) Copyright 1999 Linus Torvalds
 *
 * Common interfaces for "ptrace()" which we do not want
 * to continually duplicate across every architecture.
 */

#include <linux/capability.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/sched/coredump.h>
#include <linux/sched/task.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/ptrace.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/uio.h>
#include <linux/audit.h>
#include <linux/pid_namespace.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <linux/regset.h>
#include <linux/hw_breakpoint.h>
#include <linux/cn_proc.h>
#include <linux/compat.h>

/*
 * Access another process' address space via ptrace.
 * Source/target buffer must be kernel space,
 * Do not walk the page table directly, use get_user_pages
 */


int ptrace_access_vm(struct task_struct *tsk, unsigned long addr,
		     void *buf, int len, unsigned int gup_flags)
{
	struct mm_struct *mm;
	int ret;

	mm = get_task_mm(tsk);
	if (!mm)
		return 0;

	if (!tsk->ptrace ||
	    (current != tsk->parent) ||
	    ((get_dumpable(mm) != SUID_DUMP_USER) &&
	     !ptracer_capable(tsk, mm->user_ns))) {
		mmput(mm);
		return 0;
	}

	ret = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags);
	mmput(mm);

	return ret;
}


Contributors
Person
Tokens
Prop
Commits
CommitProp
Eric W. Biedermann
119
100.00%
1
100.00%
Total
119
100.00%
1
100.00%



void __ptrace_link(struct task_struct *child, struct task_struct *new_parent,
		   const struct cred *ptracer_cred)
{
	BUG_ON(!list_empty(&child->ptrace_entry));
	list_add(&child->ptrace_entry, &new_parent->ptraced);
	child->parent = new_parent;
	child->ptracer_cred = get_cred(ptracer_cred);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Ingo Molnar
38
62.30%
2
33.33%
Eric W. Biedermann
16
26.23%
2
33.33%
Roland McGrath
4
6.56%
1
16.67%
Eric Sesterhenn / Snakebyte
3
4.92%
1
16.67%
Total
61
100.00%
6
100.00%

/*
 * ptrace a task: make the debugger its new parent and
 * move it to the ptrace list.
 *
 * Must be called with the tasklist lock write-held.
 */


static void ptrace_link(struct task_struct *child, struct task_struct *new_parent)
{
	rcu_read_lock();
	__ptrace_link(child, new_parent, __task_cred(new_parent));
	rcu_read_unlock();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Eric W. Biedermann
33
97.06%
2
66.67%
Ingo Molnar
1
2.94%
1
33.33%
Total
34
100.00%
3
100.00%

/**
 * __ptrace_unlink - unlink ptracee and restore its execution state
 * @child: ptracee to be unlinked
 *
 * Remove @child from the ptrace list, move it back to the original parent,
 * and restore the execution state so that it conforms to the group stop
 * state.
 *
 * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
 * exiting.  For PTRACE_DETACH, unless the ptracee has been killed between
 * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
 * If the ptracer is exiting, the ptracee can be in any state.
 *
 * After detach, the ptracee should be in a state which conforms to the
 * group stop.  If the group is stopped or in the process of stopping, the
 * ptracee should be put into TASK_STOPPED; otherwise, it should be woken
 * up from TASK_TRACED.
 *
 * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
 * it goes through TRACED -> RUNNING -> STOPPED transition which is similar
 * to but in the opposite direction of what happens while attaching to a
 * stopped task.  However, in this direction, the intermediate RUNNING
 * state is not hidden even from the current ptracer and if it immediately
 * re-attaches and performs a WNOHANG wait(2), it may fail.
 *
 * CONTEXT:
 * write_lock_irq(tasklist_lock)
 */


void __ptrace_unlink(struct task_struct *child)
{
	const struct cred *old_cred;
	BUG_ON(!child->ptrace);

	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

	child->parent = child->real_parent;
	list_del_init(&child->ptrace_entry);
	old_cred = child->ptracer_cred;
	child->ptracer_cred = NULL;
	put_cred(old_cred);

	spin_lock(&child->sighand->siglock);
	child->ptrace = 0;
	/*
         * Clear all pending traps and TRAPPING.  TRAPPING should be
         * cleared regardless of JOBCTL_STOP_PENDING.  Do it explicitly.
         */
	task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
	task_clear_jobctl_trapping(child);

	/*
         * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
         * @child isn't dead.
         */
	if (!(child->flags & PF_EXITING) &&
	    (child->signal->flags & SIGNAL_STOP_STOPPED ||
	     child->signal->group_stop_count)) {
		child->jobctl |= JOBCTL_STOP_PENDING;

		/*
                 * This is only possible if this thread was cloned by the
                 * traced task running in the stopped group, set the signal
                 * for the future reports.
                 * FIXME: we should change ptrace_init_task() to handle this
                 * case.
                 */
		if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
			child->jobctl |= SIGSTOP;
	}

	/*
         * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
         * @child in the butt.  Note that @resume should be used iff @child
         * is in TASK_TRACED; otherwise, we might unduly disrupt
         * TASK_KILLABLE sleeps.
         */
	if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
		ptrace_signal_wake_up(child, true);

	spin_unlock(&child->sighand->siglock);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Roland McGrath
56
31.46%
5
26.32%
Tejun Heo
44
24.72%
5
26.32%
Oleg Nesterov
32
17.98%
4
21.05%
Eric W. Biedermann
23
12.92%
1
5.26%
Ingo Molnar
13
7.30%
2
10.53%
Ales Novak
7
3.93%
1
5.26%
Matthew Wilcox
3
1.69%
1
5.26%
Total
178
100.00%
19
100.00%

/* Ensure that nothing can wake it up, even SIGKILL */


static bool ptrace_freeze_traced(struct task_struct *task)
{
	bool ret = false;

	/* Lockless, nobody but us can set this flag */
	if (task->jobctl & JOBCTL_LISTENING)
		return ret;

	spin_lock_irq(&task->sighand->siglock);
	if (task_is_traced(task) && !__fatal_signal_pending(task)) {
		task->state = __TASK_TRACED;
		ret = true;
	}
	spin_unlock_irq(&task->sighand->siglock);

	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Oleg Nesterov
76
100.00%
1
100.00%
Total
76
100.00%
1
100.00%



static void ptrace_unfreeze_traced(struct task_struct *task)
{
	if (task->state != __TASK_TRACED)
		return;

	WARN_ON(!task->ptrace || task->parent != current);

	/*
         * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
         * Recheck state under the lock to close this race.
         */
	spin_lock_irq(&task->sighand->siglock);
	if (task->state == __TASK_TRACED) {
		if (__fatal_signal_pending(task))
			wake_up_state(task, __TASK_TRACED);
		else
			task->state = TASK_TRACED;
	}
	spin_unlock_irq(&task->sighand->siglock);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Oleg Nesterov
75
87.21%
1
50.00%
Ben Segall
11
12.79%
1
50.00%
Total
86
100.00%
2
100.00%

/**
 * ptrace_check_attach - check whether ptracee is ready for ptrace operation
 * @child: ptracee to check for
 * @ignore_state: don't check whether @child is currently %TASK_TRACED
 *
 * Check whether @child is being ptraced by %current and ready for further
 * ptrace operations.  If @ignore_state is %false, @child also should be in
 * %TASK_TRACED state and on return the child is guaranteed to be traced
 * and not executing.  If @ignore_state is %true, @child can be in any
 * state.
 *
 * CONTEXT:
 * Grabs and releases tasklist_lock and @child->sighand->siglock.
 *
 * RETURNS:
 * 0 on success, -ESRCH if %child is not ready.
 */


static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
{
	int ret = -ESRCH;

	/*
         * We take the read lock around doing both checks to close a
         * possible race where someone else was tracing our child and
         * detached between these two checks.  After this locked check,
         * we are sure that this is our traced child and that can only
         * be changed by us so it's not changing right after this.
         */
	read_lock(&tasklist_lock);
	if (child->ptrace && child->parent == current) {
		WARN_ON(child->state == __TASK_TRACED);
		/*
                 * child->sighand can't be NULL, release_task()
                 * does ptrace_unlink() before __exit_signal().
                 */
		if (ignore_state || ptrace_freeze_traced(child))
			ret = 0;
	}
	read_unlock(&tasklist_lock);

	if (!ret && !ignore_state) {
		if (!wait_task_inactive(child, __TASK_TRACED)) {
			/*
                         * This can only happen if may_ptrace_stop() fails and
                         * ptrace_stop() changes ->state back to TASK_RUNNING,
                         * so we should not worry about leaking __TASK_TRACED.
                         */
			WARN_ON(child->state == __TASK_TRACED);
			ret = -ESRCH;
		}
	}

	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Roland McGrath
41
37.27%
3
25.00%
Linus Torvalds
31
28.18%
2
16.67%
Oleg Nesterov
30
27.27%
3
25.00%
Tejun Heo
5
4.55%
2
16.67%
Matthew Wilcox
2
1.82%
1
8.33%
David Howells
1
0.91%
1
8.33%
Total
110
100.00%
12
100.00%



static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
{
	if (mode & PTRACE_MODE_NOAUDIT)
		return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
	else
		return has_ns_capability(current, ns, CAP_SYS_PTRACE);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Eric Paris
42
100.00%
1
100.00%
Total
42
100.00%
1
100.00%

/* Returns 0 on success, -errno on denial. */


static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
{
	const struct cred *cred = current_cred(), *tcred;
	struct mm_struct *mm;
	kuid_t caller_uid;
	kgid_t caller_gid;

	if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
		WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
		return -EPERM;
	}

	/* May we inspect the given task?
         * This check is used both for attaching with ptrace
         * and for allowing access to sensitive information in /proc.
         *
         * ptrace_attach denies several cases that /proc allows
         * because setting up the necessary parent/child relationship
         * or halting the specified task is impossible.
         */

	/* Don't let security modules deny introspection */
	if (same_thread_group(task, current))
		return 0;
	rcu_read_lock();
	if (mode & PTRACE_MODE_FSCREDS) {
		caller_uid = cred->fsuid;
		caller_gid = cred->fsgid;
	} else {
		/*
                 * Using the euid would make more sense here, but something
                 * in userland might rely on the old behavior, and this
                 * shouldn't be a security problem since
                 * PTRACE_MODE_REALCREDS implies that the caller explicitly
                 * used a syscall that requests access to another process
                 * (and not a filesystem syscall to procfs).
                 */
		caller_uid = cred->uid;
		caller_gid = cred->gid;
	}
	tcred = __task_cred(task);
	if (uid_eq(caller_uid, tcred->euid) &&
	    uid_eq(caller_uid, tcred->suid) &&
	    uid_eq(caller_uid, tcred->uid)  &&
	    gid_eq(caller_gid, tcred->egid) &&
	    gid_eq(caller_gid, tcred->sgid) &&
	    gid_eq(caller_gid, tcred->gid))
		goto ok;
	if (ptrace_has_cap(tcred->user_ns, mode))
		goto ok;
	rcu_read_unlock();
	return -EPERM;
ok:
	rcu_read_unlock();
	mm = task->mm;
	if (mm &&
	    ((get_dumpable(mm) != SUID_DUMP_USER) &&
	     !ptrace_has_cap(mm->user_ns, mode)))
	    return -EPERM;

	return security_ptrace_access_check(task, mode);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jann Horn
78
30.59%
1
5.88%
Eric W. Biedermann
50
19.61%
4
23.53%
Linus Torvalds
36
14.12%
1
5.88%
David Howells
34
13.33%
2
11.76%
Serge E. Hallyn
21
8.24%
1
5.88%
Miklos Szeredi
16
6.27%
1
5.88%
Stephen D. Smalley
7
2.75%
1
5.88%
Eric Paris
5
1.96%
2
11.76%
Mark A. Grondona
4
1.57%
1
5.88%
Kees Cook
2
0.78%
1
5.88%
Ingo Molnar
1
0.39%
1
5.88%
Tetsuo Handa
1
0.39%
1
5.88%
Total
255
100.00%
17
100.00%



bool ptrace_may_access(struct task_struct *task, unsigned int mode)
{
	int err;
	task_lock(task);
	err = __ptrace_may_access(task, mode);
	task_unlock(task);
	return !err;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Miklos Szeredi
31
77.50%
1
50.00%
Stephen D. Smalley
9
22.50%
1
50.00%
Total
40
100.00%
2
100.00%



static int ptrace_attach(struct task_struct *task, long request,
			 unsigned long addr,
			 unsigned long flags)
{
	bool seize = (request == PTRACE_SEIZE);
	int retval;

	retval = -EIO;
	if (seize) {
		if (addr != 0)
			goto out;
		if (flags & ~(unsigned long)PTRACE_O_MASK)
			goto out;
		flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
	} else {
		flags = PT_PTRACED;
	}

	audit_ptrace(task);

	retval = -EPERM;
	if (unlikely(task->flags & PF_KTHREAD))
		goto out;
	if (same_thread_group(task, current))
		goto out;

	/*
         * Protect exec's credential calculations against our interference;
         * SUID, SGID and LSM creds get determined differently
         * under ptrace.
         */
	retval = -ERESTARTNOINTR;
	if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
		goto out;

	task_lock(task);
	retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
	task_unlock(task);
	if (retval)
		goto unlock_creds;

	write_lock_irq(&tasklist_lock);
	retval = -EPERM;
	if (unlikely(task->exit_state))
		goto unlock_tasklist;
	if (task->ptrace)
		goto unlock_tasklist;

	if (seize)
		flags |= PT_SEIZED;
	task->ptrace = flags;

	ptrace_link(task, current);

	/* SEIZE doesn't trap tracee on attach */
	if (!seize)
		send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);

	spin_lock(&task->sighand->siglock);

	/*
         * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
         * TRAPPING, and kick it so that it transits to TRACED.  TRAPPING
         * will be cleared if the child completes the transition or any
         * event which clears the group stop states happens.  We'll wait
         * for the transition to complete before returning from this
         * function.
         *
         * This hides STOPPED -> RUNNING -> TRACED transition from the
         * attaching thread but a different thread in the same group can
         * still observe the transient RUNNING state.  IOW, if another
         * thread's WNOHANG wait(2) on the stopped tracee races against
         * ATTACH, the wait(2) may fail due to the transient RUNNING.
         *
         * The following task_is_stopped() test is safe as both transitions
         * in and out of STOPPED are protected by siglock.
         */
	if (task_is_stopped(task) &&
	    task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
		signal_wake_up_state(task, __TASK_STOPPED);

	spin_unlock(&task->sighand->siglock);

	retval = 0;
unlock_tasklist:
	write_unlock_irq(&tasklist_lock);
unlock_creds:
	mutex_unlock(&task->signal->cred_guard_mutex);
out:
	if (!retval) {
		/*
                 * We do not bother to change retval or clear JOBCTL_TRAPPING
                 * if wait_on_bit() was interrupted by SIGKILL. The tracer will
                 * not return to user-mode, it will exit and clear this bit in
                 * __ptrace_unlink() if it wasn't already cleared by the tracee;
                 * and until then nobody can ptrace this task.
                 */
		wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE);
		proc_ptrace_connector(task, PTRACE_ATTACH);
	}

	return retval;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Tejun Heo
93
27.51%
7
20.59%
Oleg Nesterov
71
21.01%
7
20.59%
Denys Vlasenko
53
15.68%
2
5.88%
Linus Torvalds
44
13.02%
5
14.71%
Miklos Szeredi
22
6.51%
1
2.94%
David Howells
19
5.62%
2
5.88%
Vladimir Zapolskiy
9
2.66%
1
2.94%
Greg Kroah-Hartman
6
1.78%
2
5.88%
Eric W. Biedermann
6
1.78%
2
5.88%
Al Viro
5
1.48%
1
2.94%
Pavel Emelyanov
4
1.18%
1
2.94%
Motohiro Kosaki
4
1.18%
1
2.94%
Jann Horn
1
0.30%
1
2.94%
Ingo Molnar
1
0.30%
1
2.94%
Total
338
100.00%
34
100.00%

/**
 * ptrace_traceme  --  helper for PTRACE_TRACEME
 *
 * Performs checks and sets PT_PTRACED.
 * Should be used by all ptrace implementations for PTRACE_TRACEME.
 */


static int ptrace_traceme(void)
{
	int ret = -EPERM;

	write_lock_irq(&tasklist_lock);
	/* Are we already being traced? */
	if (!current->ptrace) {
		ret = security_ptrace_traceme(current->parent);
		/*
                 * Check PF_EXITING to ensure ->real_parent has not passed
                 * exit_ptrace(). Otherwise we don't report the error but
                 * pretend ->real_parent untraces us right after return.
                 */
		if (!ret && !(current->real_parent->flags & PF_EXITING)) {
			current->ptrace = PT_PTRACED;
			ptrace_link(current, current->real_parent);
		}
	}
	write_unlock_irq(&tasklist_lock);

	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Oleg Nesterov
80
97.56%
2
50.00%
Linus Torvalds
1
1.22%
1
25.00%
Eric W. Biedermann
1
1.22%
1
25.00%
Total
82
100.00%
4
100.00%

/*
 * Called with irqs disabled, returns true if childs should reap themselves.
 */


static int ignoring_children(struct sighand_struct *sigh)
{
	int ret;
	spin_lock(&sigh->siglock);
	ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
	      (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
	spin_unlock(&sigh->siglock);
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Oleg Nesterov
69
100.00%
1
100.00%
Total
69
100.00%
1
100.00%

/*
 * Called with tasklist_lock held for writing.
 * Unlink a traced task, and clean it up if it was a traced zombie.
 * Return true if it needs to be reaped with release_task().
 * (We can't call release_task() here because we already hold tasklist_lock.)
 *
 * If it's a zombie, our attachedness prevented normal parent notification
 * or self-reaping.  Do notification now if it would have happened earlier.
 * If it should reap itself, return true.
 *
 * If it's our own child, there is no notification to do. But if our normal
 * children self-reap, then this child was prevented by ptrace and we must
 * reap it now, in that case we must also wake up sub-threads sleeping in
 * do_wait().
 */


static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
{
	bool dead;

	__ptrace_unlink(p);

	if (p->exit_state != EXIT_ZOMBIE)
		return false;

	dead = !thread_group_leader(p);

	if (!dead && thread_group_empty(p)) {
		if (!same_thread_group(p->real_parent, tracer))
			dead = do_notify_parent(p, p->exit_signal);
		else if (ignoring_children(tracer->sighand)) {
			__wake_up_parent(p, tracer);
			dead = true;
		}
	}
	/* Mark it as in the process of being reaped. */
	if (dead)
		p->exit_state = EXIT_DEAD;
	return dead;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Oleg Nesterov
115
100.00%
3
100.00%
Total
115
100.00%
3
100.00%



static int ptrace_detach(struct task_struct *child, unsigned int data)
{
	if (!valid_signal(data))
		return -EIO;

	/* Architecture-specific hardware disable .. */
	ptrace_disable(child);

	write_lock_irq(&tasklist_lock);
	/*
         * We rely on ptrace_freeze_traced(). It can't be killed and
         * untraced by another thread, it can't be a zombie.
         */
	WARN_ON(!child->ptrace || child->exit_state);
	/*
         * tasklist_lock avoids the race with wait_task_stopped(), see
         * the comment in ptrace_resume().
         */
	child->exit_code = data;
	__ptrace_detach(current, child);
	write_unlock_irq(&tasklist_lock);

	proc_ptrace_connector(child, PTRACE_DETACH);

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
47
57.32%
2
25.00%
Oleg Nesterov
24
29.27%
4
50.00%
Vladimir Zapolskiy
7
8.54%
1
12.50%
Jesper Juhl
4
4.88%
1
12.50%
Total
82
100.00%
8
100.00%

/*
 * Detach all tasks we were using ptrace on. Called with tasklist held
 * for writing.
 */


void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
{
	struct task_struct *p, *n;

	list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
		if (unlikely(p->ptrace & PT_EXITKILL))
			send_sig_info(SIGKILL, SEND_SIG_FORCED, p);

		if (__ptrace_detach(tracer, p))
			list_add(&p->ptrace_entry, dead);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Oleg Nesterov
74
100.00%
3
100.00%
Total
74
100.00%
3
100.00%



int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
{
	int copied = 0;

	while (len > 0) {
		char buf[128];
		int this_len, retval;

		this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
		retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE);

		if (!retval) {
			if (copied)
				break;
			return -EIO;
		}
		if (copy_to_user(dst, buf, retval))
			return -EFAULT;
		copied += retval;
		src += retval;
		dst += retval;
		len -= retval;
	}
	return copied;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
126
97.67%
2
40.00%
Linus Torvalds
1
0.78%
1
20.00%
Lorenzo Stoakes
1
0.78%
1
20.00%
Eric W. Biedermann
1
0.78%
1
20.00%
Total
129
100.00%
5
100.00%



int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
{
	int copied = 0;

	while (len > 0) {
		char buf[128];
		int this_len, retval;

		this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
		if (copy_from_user(buf, src, this_len))
			return -EFAULT;
		retval = ptrace_access_vm(tsk, dst, buf, this_len,
				FOLL_FORCE | FOLL_WRITE);
		if (!retval) {
			if (copied)
				break;
			return -EIO;
		}
		copied += retval;
		src += retval;
		dst += retval;
		len -= retval;
	}
	return copied;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
126
96.18%
2
40.00%
Lorenzo Stoakes
3
2.29%
1
20.00%
Eric W. Biedermann
1
0.76%
1
20.00%
Linus Torvalds
1
0.76%
1
20.00%
Total
131
100.00%
5
100.00%



static int ptrace_setoptions(struct task_struct *child, unsigned long data)
{
	unsigned flags;

	if (data & ~(unsigned long)PTRACE_O_MASK)
		return -EINVAL;

	if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) {
		if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) ||
		    !IS_ENABLED(CONFIG_SECCOMP))
			return -EINVAL;

		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;

		if (seccomp_mode(&current->seccomp) != SECCOMP_MODE_DISABLED ||
		    current->ptrace & PT_SUSPEND_SECCOMP)
			return -EPERM;
	}

	/* Avoid intermediate state when all opts are cleared */
	flags = child->ptrace;
	flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
	flags |= (data << PT_OPT_FLAG_SHIFT);
	child->ptrace = flags;

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Tycho Andersen
61
47.29%
1
11.11%
Denys Vlasenko
35
27.13%
2
22.22%
Daniel Jacobowitz
30
23.26%
4
44.44%
Masahiro Yamada
2
1.55%
1
11.11%
Namhyung Kim
1
0.78%
1
11.11%
Total
129
100.00%
9
100.00%



static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
{
	unsigned long flags;
	int error = -ESRCH;

	if (lock_task_sighand(child, &flags)) {
		error = -EINVAL;
		if (likely(child->last_siginfo != NULL)) {
			*info = *child->last_siginfo;
			error = 0;
		}
		unlock_task_sighand(child, &flags);
	}
	return error;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Prasanna Meda
41
52.56%
2
28.57%
Daniel Jacobowitz
17
21.79%
1
14.29%
Oleg Nesterov
12
15.38%
1
14.29%
Roland McGrath
6
7.69%
2
28.57%
Linus Torvalds
2
2.56%
1
14.29%
Total
78
100.00%
7
100.00%



static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
{
	unsigned long flags;
	int error = -ESRCH;

	if (lock_task_sighand(child, &flags)) {
		error = -EINVAL;
		if (likely(child->last_siginfo != NULL)) {
			*child->last_siginfo = *info;
			error = 0;
		}
		unlock_task_sighand(child, &flags);
	}
	return error;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Prasanna Meda
42
53.16%
2
33.33%
Daniel Jacobowitz
19
24.05%
1
16.67%
Oleg Nesterov
12
15.19%
1
16.67%
Roland McGrath
4
5.06%
1
16.67%
Linus Torvalds
2
2.53%
1
16.67%
Total
79
100.00%
6
100.00%



static int ptrace_peek_siginfo(struct task_struct *child,
				unsigned long addr,
				unsigned long data)
{
	struct ptrace_peeksiginfo_args arg;
	struct sigpending *pending;
	struct sigqueue *q;
	int ret, i;

	ret = copy_from_user(&arg, (void __user *) addr,
				sizeof(struct ptrace_peeksiginfo_args));
	if (ret)
		return -EFAULT;

	if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
		return -EINVAL; /* unknown flags */

	if (arg.nr < 0)
		return -EINVAL;

	if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
		pending = &child->signal->shared_pending;
	else
		pending = &child->pending;

	for (i = 0; i < arg.nr; ) {
		siginfo_t info;
		s32 off = arg.off + i;

		spin_lock_irq(&child->sighand->siglock);
		list_for_each_entry(q, &pending->list, list) {
			if (!off--) {
				copy_siginfo(&info, &q->info);
				break;
			}
		}
		spin_unlock_irq(&child->sighand->siglock);

		if (off >= 0) /* beyond the end of the list */
			break;

#ifdef CONFIG_COMPAT
		if (unlikely(in_compat_syscall())) {
			compat_siginfo_t __user *uinfo = compat_ptr(data);

			if (copy_siginfo_to_user32(uinfo, &info)) {
				ret = -EFAULT;
				break;
			}

		} else
#endif
		{
			siginfo_t __user *uinfo = (siginfo_t __user *) data;

			if (copy_siginfo_to_user(uinfo, &info)) {
				ret = -EFAULT;
				break;
			}
		}

		data += sizeof(siginfo_t);
		i++;

		if (signal_pending(current))
			break;

		cond_resched();
	}

	if (i > 0)
		return i;

	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrey Vagin
298
95.51%
1
33.33%
Mathieu Desnoyers
13
4.17%
1
33.33%
Andrew Lutomirski
1
0.32%
1
33.33%
Total
312
100.00%
3
100.00%

#ifdef PTRACE_SINGLESTEP

#define is_singlestep(request)		((request) == PTRACE_SINGLESTEP)
#else

#