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7c8bd2322c
Now that forget_original_parent() uses ->ptrace_entry for EXIT_DEAD tasks, we can simply pass "dead_children" list to exit_ptrace() and remove another release_task() loop. Plus this way we do not need to drop and reacquire tasklist_lock. Also shift the list_empty(ptraced) check, if we want this optimization it makes sense to eliminate the function call altogether. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com>, Cc: Sterling Alexander <stalexan@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roland McGrath <roland@hack.frob.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1202 lines
29 KiB
C
1202 lines
29 KiB
C
/*
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* linux/kernel/ptrace.c
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*
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* (C) Copyright 1999 Linus Torvalds
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*
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* Common interfaces for "ptrace()" which we do not want
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* to continually duplicate across every architecture.
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*/
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#include <linux/capability.h>
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#include <linux/export.h>
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#include <linux/sched.h>
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#include <linux/errno.h>
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#include <linux/mm.h>
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#include <linux/highmem.h>
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#include <linux/pagemap.h>
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#include <linux/ptrace.h>
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#include <linux/security.h>
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#include <linux/signal.h>
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#include <linux/uio.h>
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#include <linux/audit.h>
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#include <linux/pid_namespace.h>
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#include <linux/syscalls.h>
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#include <linux/uaccess.h>
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#include <linux/regset.h>
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#include <linux/hw_breakpoint.h>
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#include <linux/cn_proc.h>
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#include <linux/compat.h>
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/*
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* ptrace a task: make the debugger its new parent and
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* move it to the ptrace list.
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*
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* Must be called with the tasklist lock write-held.
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*/
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void __ptrace_link(struct task_struct *child, struct task_struct *new_parent)
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{
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BUG_ON(!list_empty(&child->ptrace_entry));
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list_add(&child->ptrace_entry, &new_parent->ptraced);
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child->parent = new_parent;
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}
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/**
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* __ptrace_unlink - unlink ptracee and restore its execution state
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* @child: ptracee to be unlinked
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*
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* Remove @child from the ptrace list, move it back to the original parent,
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* and restore the execution state so that it conforms to the group stop
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* state.
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*
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* Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer
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* exiting. For PTRACE_DETACH, unless the ptracee has been killed between
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* ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED.
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* If the ptracer is exiting, the ptracee can be in any state.
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*
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* After detach, the ptracee should be in a state which conforms to the
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* group stop. If the group is stopped or in the process of stopping, the
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* ptracee should be put into TASK_STOPPED; otherwise, it should be woken
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* up from TASK_TRACED.
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*
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* If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED,
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* it goes through TRACED -> RUNNING -> STOPPED transition which is similar
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* to but in the opposite direction of what happens while attaching to a
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* stopped task. However, in this direction, the intermediate RUNNING
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* state is not hidden even from the current ptracer and if it immediately
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* re-attaches and performs a WNOHANG wait(2), it may fail.
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*
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* CONTEXT:
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* write_lock_irq(tasklist_lock)
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*/
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void __ptrace_unlink(struct task_struct *child)
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{
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BUG_ON(!child->ptrace);
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child->ptrace = 0;
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child->parent = child->real_parent;
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list_del_init(&child->ptrace_entry);
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spin_lock(&child->sighand->siglock);
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/*
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* Clear all pending traps and TRAPPING. TRAPPING should be
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* cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
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*/
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task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
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task_clear_jobctl_trapping(child);
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/*
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* Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
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* @child isn't dead.
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*/
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if (!(child->flags & PF_EXITING) &&
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(child->signal->flags & SIGNAL_STOP_STOPPED ||
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child->signal->group_stop_count)) {
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child->jobctl |= JOBCTL_STOP_PENDING;
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/*
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* This is only possible if this thread was cloned by the
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* traced task running in the stopped group, set the signal
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* for the future reports.
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* FIXME: we should change ptrace_init_task() to handle this
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* case.
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*/
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if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
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child->jobctl |= SIGSTOP;
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}
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/*
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* If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
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* @child in the butt. Note that @resume should be used iff @child
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* is in TASK_TRACED; otherwise, we might unduly disrupt
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* TASK_KILLABLE sleeps.
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*/
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if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
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ptrace_signal_wake_up(child, true);
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spin_unlock(&child->sighand->siglock);
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}
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/* Ensure that nothing can wake it up, even SIGKILL */
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static bool ptrace_freeze_traced(struct task_struct *task)
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{
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bool ret = false;
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/* Lockless, nobody but us can set this flag */
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if (task->jobctl & JOBCTL_LISTENING)
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return ret;
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spin_lock_irq(&task->sighand->siglock);
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if (task_is_traced(task) && !__fatal_signal_pending(task)) {
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task->state = __TASK_TRACED;
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ret = true;
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}
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spin_unlock_irq(&task->sighand->siglock);
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return ret;
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}
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static void ptrace_unfreeze_traced(struct task_struct *task)
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{
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if (task->state != __TASK_TRACED)
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return;
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WARN_ON(!task->ptrace || task->parent != current);
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spin_lock_irq(&task->sighand->siglock);
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if (__fatal_signal_pending(task))
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wake_up_state(task, __TASK_TRACED);
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else
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task->state = TASK_TRACED;
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spin_unlock_irq(&task->sighand->siglock);
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}
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/**
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* ptrace_check_attach - check whether ptracee is ready for ptrace operation
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* @child: ptracee to check for
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* @ignore_state: don't check whether @child is currently %TASK_TRACED
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*
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* Check whether @child is being ptraced by %current and ready for further
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* ptrace operations. If @ignore_state is %false, @child also should be in
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* %TASK_TRACED state and on return the child is guaranteed to be traced
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* and not executing. If @ignore_state is %true, @child can be in any
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* state.
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*
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* CONTEXT:
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* Grabs and releases tasklist_lock and @child->sighand->siglock.
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*
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* RETURNS:
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* 0 on success, -ESRCH if %child is not ready.
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*/
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static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
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{
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int ret = -ESRCH;
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/*
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* We take the read lock around doing both checks to close a
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* possible race where someone else was tracing our child and
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* detached between these two checks. After this locked check,
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* we are sure that this is our traced child and that can only
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* be changed by us so it's not changing right after this.
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*/
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read_lock(&tasklist_lock);
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if (child->ptrace && child->parent == current) {
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WARN_ON(child->state == __TASK_TRACED);
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/*
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* child->sighand can't be NULL, release_task()
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* does ptrace_unlink() before __exit_signal().
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*/
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if (ignore_state || ptrace_freeze_traced(child))
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ret = 0;
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}
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read_unlock(&tasklist_lock);
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if (!ret && !ignore_state) {
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if (!wait_task_inactive(child, __TASK_TRACED)) {
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/*
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* This can only happen if may_ptrace_stop() fails and
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* ptrace_stop() changes ->state back to TASK_RUNNING,
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* so we should not worry about leaking __TASK_TRACED.
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*/
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WARN_ON(child->state == __TASK_TRACED);
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ret = -ESRCH;
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}
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}
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return ret;
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}
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static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
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{
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if (mode & PTRACE_MODE_NOAUDIT)
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return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
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else
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return has_ns_capability(current, ns, CAP_SYS_PTRACE);
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}
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/* Returns 0 on success, -errno on denial. */
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static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
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{
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const struct cred *cred = current_cred(), *tcred;
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/* May we inspect the given task?
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* This check is used both for attaching with ptrace
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* and for allowing access to sensitive information in /proc.
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*
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* ptrace_attach denies several cases that /proc allows
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* because setting up the necessary parent/child relationship
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* or halting the specified task is impossible.
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*/
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int dumpable = 0;
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/* Don't let security modules deny introspection */
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if (same_thread_group(task, current))
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return 0;
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rcu_read_lock();
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tcred = __task_cred(task);
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if (uid_eq(cred->uid, tcred->euid) &&
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uid_eq(cred->uid, tcred->suid) &&
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uid_eq(cred->uid, tcred->uid) &&
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gid_eq(cred->gid, tcred->egid) &&
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gid_eq(cred->gid, tcred->sgid) &&
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gid_eq(cred->gid, tcred->gid))
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goto ok;
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if (ptrace_has_cap(tcred->user_ns, mode))
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goto ok;
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rcu_read_unlock();
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return -EPERM;
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ok:
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rcu_read_unlock();
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smp_rmb();
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if (task->mm)
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dumpable = get_dumpable(task->mm);
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rcu_read_lock();
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if (dumpable != SUID_DUMP_USER &&
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!ptrace_has_cap(__task_cred(task)->user_ns, mode)) {
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rcu_read_unlock();
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return -EPERM;
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}
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rcu_read_unlock();
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return security_ptrace_access_check(task, mode);
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}
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bool ptrace_may_access(struct task_struct *task, unsigned int mode)
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{
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int err;
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task_lock(task);
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err = __ptrace_may_access(task, mode);
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task_unlock(task);
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return !err;
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}
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static int ptrace_attach(struct task_struct *task, long request,
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unsigned long addr,
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unsigned long flags)
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{
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bool seize = (request == PTRACE_SEIZE);
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int retval;
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retval = -EIO;
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if (seize) {
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if (addr != 0)
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goto out;
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if (flags & ~(unsigned long)PTRACE_O_MASK)
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goto out;
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flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
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} else {
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flags = PT_PTRACED;
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}
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audit_ptrace(task);
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retval = -EPERM;
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if (unlikely(task->flags & PF_KTHREAD))
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goto out;
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if (same_thread_group(task, current))
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goto out;
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/*
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* Protect exec's credential calculations against our interference;
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* SUID, SGID and LSM creds get determined differently
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* under ptrace.
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*/
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retval = -ERESTARTNOINTR;
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if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
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goto out;
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task_lock(task);
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retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
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task_unlock(task);
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if (retval)
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goto unlock_creds;
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write_lock_irq(&tasklist_lock);
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retval = -EPERM;
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if (unlikely(task->exit_state))
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goto unlock_tasklist;
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if (task->ptrace)
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goto unlock_tasklist;
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if (seize)
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flags |= PT_SEIZED;
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rcu_read_lock();
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if (ns_capable(__task_cred(task)->user_ns, CAP_SYS_PTRACE))
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flags |= PT_PTRACE_CAP;
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rcu_read_unlock();
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task->ptrace = flags;
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__ptrace_link(task, current);
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/* SEIZE doesn't trap tracee on attach */
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if (!seize)
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send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
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spin_lock(&task->sighand->siglock);
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/*
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* If the task is already STOPPED, set JOBCTL_TRAP_STOP and
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* TRAPPING, and kick it so that it transits to TRACED. TRAPPING
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* will be cleared if the child completes the transition or any
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* event which clears the group stop states happens. We'll wait
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* for the transition to complete before returning from this
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* function.
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*
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* This hides STOPPED -> RUNNING -> TRACED transition from the
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* attaching thread but a different thread in the same group can
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* still observe the transient RUNNING state. IOW, if another
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* thread's WNOHANG wait(2) on the stopped tracee races against
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* ATTACH, the wait(2) may fail due to the transient RUNNING.
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*
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* The following task_is_stopped() test is safe as both transitions
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* in and out of STOPPED are protected by siglock.
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*/
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if (task_is_stopped(task) &&
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task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
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signal_wake_up_state(task, __TASK_STOPPED);
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spin_unlock(&task->sighand->siglock);
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retval = 0;
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unlock_tasklist:
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write_unlock_irq(&tasklist_lock);
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unlock_creds:
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mutex_unlock(&task->signal->cred_guard_mutex);
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out:
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if (!retval) {
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wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT,
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TASK_UNINTERRUPTIBLE);
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proc_ptrace_connector(task, PTRACE_ATTACH);
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}
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return retval;
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}
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/**
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* ptrace_traceme -- helper for PTRACE_TRACEME
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*
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* Performs checks and sets PT_PTRACED.
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* Should be used by all ptrace implementations for PTRACE_TRACEME.
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*/
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static int ptrace_traceme(void)
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{
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int ret = -EPERM;
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write_lock_irq(&tasklist_lock);
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/* Are we already being traced? */
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if (!current->ptrace) {
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ret = security_ptrace_traceme(current->parent);
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/*
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* Check PF_EXITING to ensure ->real_parent has not passed
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* exit_ptrace(). Otherwise we don't report the error but
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* pretend ->real_parent untraces us right after return.
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*/
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if (!ret && !(current->real_parent->flags & PF_EXITING)) {
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current->ptrace = PT_PTRACED;
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__ptrace_link(current, current->real_parent);
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}
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}
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write_unlock_irq(&tasklist_lock);
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return ret;
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}
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/*
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* Called with irqs disabled, returns true if childs should reap themselves.
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*/
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static int ignoring_children(struct sighand_struct *sigh)
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{
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int ret;
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spin_lock(&sigh->siglock);
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ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
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(sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
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spin_unlock(&sigh->siglock);
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return ret;
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}
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/*
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* Called with tasklist_lock held for writing.
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* Unlink a traced task, and clean it up if it was a traced zombie.
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* Return true if it needs to be reaped with release_task().
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* (We can't call release_task() here because we already hold tasklist_lock.)
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*
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* If it's a zombie, our attachedness prevented normal parent notification
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* or self-reaping. Do notification now if it would have happened earlier.
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* If it should reap itself, return true.
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*
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* If it's our own child, there is no notification to do. But if our normal
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* children self-reap, then this child was prevented by ptrace and we must
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* reap it now, in that case we must also wake up sub-threads sleeping in
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* do_wait().
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*/
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static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
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{
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bool dead;
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__ptrace_unlink(p);
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if (p->exit_state != EXIT_ZOMBIE)
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return false;
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dead = !thread_group_leader(p);
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|
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if (!dead && thread_group_empty(p)) {
|
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if (!same_thread_group(p->real_parent, tracer))
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dead = do_notify_parent(p, p->exit_signal);
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else if (ignoring_children(tracer->sighand)) {
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__wake_up_parent(p, tracer);
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dead = true;
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}
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}
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/* Mark it as in the process of being reaped. */
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if (dead)
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p->exit_state = EXIT_DEAD;
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return dead;
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}
|
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|
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static int ptrace_detach(struct task_struct *child, unsigned int data)
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{
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bool dead = false;
|
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|
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if (!valid_signal(data))
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return -EIO;
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|
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/* Architecture-specific hardware disable .. */
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ptrace_disable(child);
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clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
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|
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write_lock_irq(&tasklist_lock);
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/*
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* This child can be already killed. Make sure de_thread() or
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* our sub-thread doing do_wait() didn't do release_task() yet.
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*/
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if (child->ptrace) {
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child->exit_code = data;
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dead = __ptrace_detach(current, child);
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}
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write_unlock_irq(&tasklist_lock);
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|
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proc_ptrace_connector(child, PTRACE_DETACH);
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if (unlikely(dead))
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release_task(child);
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return 0;
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}
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|
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/*
|
|
* 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);
|
|
}
|
|
}
|
|
|
|
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 = access_process_vm(tsk, src, buf, this_len, 0);
|
|
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;
|
|
}
|
|
|
|
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 = access_process_vm(tsk, dst, buf, this_len, 1);
|
|
if (!retval) {
|
|
if (copied)
|
|
break;
|
|
return -EIO;
|
|
}
|
|
copied += retval;
|
|
src += retval;
|
|
dst += retval;
|
|
len -= retval;
|
|
}
|
|
return copied;
|
|
}
|
|
|
|
static int ptrace_setoptions(struct task_struct *child, unsigned long data)
|
|
{
|
|
unsigned flags;
|
|
|
|
if (data & ~(unsigned long)PTRACE_O_MASK)
|
|
return -EINVAL;
|
|
|
|
/* 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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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(is_compat_task())) {
|
|
compat_siginfo_t __user *uinfo = compat_ptr(data);
|
|
|
|
if (copy_siginfo_to_user32(uinfo, &info) ||
|
|
__put_user(info.si_code, &uinfo->si_code)) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
} else
|
|
#endif
|
|
{
|
|
siginfo_t __user *uinfo = (siginfo_t __user *) data;
|
|
|
|
if (copy_siginfo_to_user(uinfo, &info) ||
|
|
__put_user(info.si_code, &uinfo->si_code)) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
}
|
|
|
|
data += sizeof(siginfo_t);
|
|
i++;
|
|
|
|
if (signal_pending(current))
|
|
break;
|
|
|
|
cond_resched();
|
|
}
|
|
|
|
if (i > 0)
|
|
return i;
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef PTRACE_SINGLESTEP
|
|
#define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
|
|
#else
|
|
#define is_singlestep(request) 0
|
|
#endif
|
|
|
|
#ifdef PTRACE_SINGLEBLOCK
|
|
#define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
|
|
#else
|
|
#define is_singleblock(request) 0
|
|
#endif
|
|
|
|
#ifdef PTRACE_SYSEMU
|
|
#define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
|
|
#else
|
|
#define is_sysemu_singlestep(request) 0
|
|
#endif
|
|
|
|
static int ptrace_resume(struct task_struct *child, long request,
|
|
unsigned long data)
|
|
{
|
|
if (!valid_signal(data))
|
|
return -EIO;
|
|
|
|
if (request == PTRACE_SYSCALL)
|
|
set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
|
|
else
|
|
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
|
|
|
|
#ifdef TIF_SYSCALL_EMU
|
|
if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
|
|
set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
|
|
else
|
|
clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
|
|
#endif
|
|
|
|
if (is_singleblock(request)) {
|
|
if (unlikely(!arch_has_block_step()))
|
|
return -EIO;
|
|
user_enable_block_step(child);
|
|
} else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
|
|
if (unlikely(!arch_has_single_step()))
|
|
return -EIO;
|
|
user_enable_single_step(child);
|
|
} else {
|
|
user_disable_single_step(child);
|
|
}
|
|
|
|
child->exit_code = data;
|
|
wake_up_state(child, __TASK_TRACED);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
|
|
|
|
static const struct user_regset *
|
|
find_regset(const struct user_regset_view *view, unsigned int type)
|
|
{
|
|
const struct user_regset *regset;
|
|
int n;
|
|
|
|
for (n = 0; n < view->n; ++n) {
|
|
regset = view->regsets + n;
|
|
if (regset->core_note_type == type)
|
|
return regset;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
|
|
struct iovec *kiov)
|
|
{
|
|
const struct user_regset_view *view = task_user_regset_view(task);
|
|
const struct user_regset *regset = find_regset(view, type);
|
|
int regset_no;
|
|
|
|
if (!regset || (kiov->iov_len % regset->size) != 0)
|
|
return -EINVAL;
|
|
|
|
regset_no = regset - view->regsets;
|
|
kiov->iov_len = min(kiov->iov_len,
|
|
(__kernel_size_t) (regset->n * regset->size));
|
|
|
|
if (req == PTRACE_GETREGSET)
|
|
return copy_regset_to_user(task, view, regset_no, 0,
|
|
kiov->iov_len, kiov->iov_base);
|
|
else
|
|
return copy_regset_from_user(task, view, regset_no, 0,
|
|
kiov->iov_len, kiov->iov_base);
|
|
}
|
|
|
|
/*
|
|
* This is declared in linux/regset.h and defined in machine-dependent
|
|
* code. We put the export here, near the primary machine-neutral use,
|
|
* to ensure no machine forgets it.
|
|
*/
|
|
EXPORT_SYMBOL_GPL(task_user_regset_view);
|
|
#endif
|
|
|
|
int ptrace_request(struct task_struct *child, long request,
|
|
unsigned long addr, unsigned long data)
|
|
{
|
|
bool seized = child->ptrace & PT_SEIZED;
|
|
int ret = -EIO;
|
|
siginfo_t siginfo, *si;
|
|
void __user *datavp = (void __user *) data;
|
|
unsigned long __user *datalp = datavp;
|
|
unsigned long flags;
|
|
|
|
switch (request) {
|
|
case PTRACE_PEEKTEXT:
|
|
case PTRACE_PEEKDATA:
|
|
return generic_ptrace_peekdata(child, addr, data);
|
|
case PTRACE_POKETEXT:
|
|
case PTRACE_POKEDATA:
|
|
return generic_ptrace_pokedata(child, addr, data);
|
|
|
|
#ifdef PTRACE_OLDSETOPTIONS
|
|
case PTRACE_OLDSETOPTIONS:
|
|
#endif
|
|
case PTRACE_SETOPTIONS:
|
|
ret = ptrace_setoptions(child, data);
|
|
break;
|
|
case PTRACE_GETEVENTMSG:
|
|
ret = put_user(child->ptrace_message, datalp);
|
|
break;
|
|
|
|
case PTRACE_PEEKSIGINFO:
|
|
ret = ptrace_peek_siginfo(child, addr, data);
|
|
break;
|
|
|
|
case PTRACE_GETSIGINFO:
|
|
ret = ptrace_getsiginfo(child, &siginfo);
|
|
if (!ret)
|
|
ret = copy_siginfo_to_user(datavp, &siginfo);
|
|
break;
|
|
|
|
case PTRACE_SETSIGINFO:
|
|
if (copy_from_user(&siginfo, datavp, sizeof siginfo))
|
|
ret = -EFAULT;
|
|
else
|
|
ret = ptrace_setsiginfo(child, &siginfo);
|
|
break;
|
|
|
|
case PTRACE_GETSIGMASK:
|
|
if (addr != sizeof(sigset_t)) {
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t)))
|
|
ret = -EFAULT;
|
|
else
|
|
ret = 0;
|
|
|
|
break;
|
|
|
|
case PTRACE_SETSIGMASK: {
|
|
sigset_t new_set;
|
|
|
|
if (addr != sizeof(sigset_t)) {
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
|
|
|
|
/*
|
|
* Every thread does recalc_sigpending() after resume, so
|
|
* retarget_shared_pending() and recalc_sigpending() are not
|
|
* called here.
|
|
*/
|
|
spin_lock_irq(&child->sighand->siglock);
|
|
child->blocked = new_set;
|
|
spin_unlock_irq(&child->sighand->siglock);
|
|
|
|
ret = 0;
|
|
break;
|
|
}
|
|
|
|
case PTRACE_INTERRUPT:
|
|
/*
|
|
* Stop tracee without any side-effect on signal or job
|
|
* control. At least one trap is guaranteed to happen
|
|
* after this request. If @child is already trapped, the
|
|
* current trap is not disturbed and another trap will
|
|
* happen after the current trap is ended with PTRACE_CONT.
|
|
*
|
|
* The actual trap might not be PTRACE_EVENT_STOP trap but
|
|
* the pending condition is cleared regardless.
|
|
*/
|
|
if (unlikely(!seized || !lock_task_sighand(child, &flags)))
|
|
break;
|
|
|
|
/*
|
|
* INTERRUPT doesn't disturb existing trap sans one
|
|
* exception. If ptracer issued LISTEN for the current
|
|
* STOP, this INTERRUPT should clear LISTEN and re-trap
|
|
* tracee into STOP.
|
|
*/
|
|
if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
|
|
ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
|
|
|
|
unlock_task_sighand(child, &flags);
|
|
ret = 0;
|
|
break;
|
|
|
|
case PTRACE_LISTEN:
|
|
/*
|
|
* Listen for events. Tracee must be in STOP. It's not
|
|
* resumed per-se but is not considered to be in TRACED by
|
|
* wait(2) or ptrace(2). If an async event (e.g. group
|
|
* stop state change) happens, tracee will enter STOP trap
|
|
* again. Alternatively, ptracer can issue INTERRUPT to
|
|
* finish listening and re-trap tracee into STOP.
|
|
*/
|
|
if (unlikely(!seized || !lock_task_sighand(child, &flags)))
|
|
break;
|
|
|
|
si = child->last_siginfo;
|
|
if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
|
|
child->jobctl |= JOBCTL_LISTENING;
|
|
/*
|
|
* If NOTIFY is set, it means event happened between
|
|
* start of this trap and now. Trigger re-trap.
|
|
*/
|
|
if (child->jobctl & JOBCTL_TRAP_NOTIFY)
|
|
ptrace_signal_wake_up(child, true);
|
|
ret = 0;
|
|
}
|
|
unlock_task_sighand(child, &flags);
|
|
break;
|
|
|
|
case PTRACE_DETACH: /* detach a process that was attached. */
|
|
ret = ptrace_detach(child, data);
|
|
break;
|
|
|
|
#ifdef CONFIG_BINFMT_ELF_FDPIC
|
|
case PTRACE_GETFDPIC: {
|
|
struct mm_struct *mm = get_task_mm(child);
|
|
unsigned long tmp = 0;
|
|
|
|
ret = -ESRCH;
|
|
if (!mm)
|
|
break;
|
|
|
|
switch (addr) {
|
|
case PTRACE_GETFDPIC_EXEC:
|
|
tmp = mm->context.exec_fdpic_loadmap;
|
|
break;
|
|
case PTRACE_GETFDPIC_INTERP:
|
|
tmp = mm->context.interp_fdpic_loadmap;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
mmput(mm);
|
|
|
|
ret = put_user(tmp, datalp);
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
#ifdef PTRACE_SINGLESTEP
|
|
case PTRACE_SINGLESTEP:
|
|
#endif
|
|
#ifdef PTRACE_SINGLEBLOCK
|
|
case PTRACE_SINGLEBLOCK:
|
|
#endif
|
|
#ifdef PTRACE_SYSEMU
|
|
case PTRACE_SYSEMU:
|
|
case PTRACE_SYSEMU_SINGLESTEP:
|
|
#endif
|
|
case PTRACE_SYSCALL:
|
|
case PTRACE_CONT:
|
|
return ptrace_resume(child, request, data);
|
|
|
|
case PTRACE_KILL:
|
|
if (child->exit_state) /* already dead */
|
|
return 0;
|
|
return ptrace_resume(child, request, SIGKILL);
|
|
|
|
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
|
|
case PTRACE_GETREGSET:
|
|
case PTRACE_SETREGSET: {
|
|
struct iovec kiov;
|
|
struct iovec __user *uiov = datavp;
|
|
|
|
if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
|
|
return -EFAULT;
|
|
|
|
if (__get_user(kiov.iov_base, &uiov->iov_base) ||
|
|
__get_user(kiov.iov_len, &uiov->iov_len))
|
|
return -EFAULT;
|
|
|
|
ret = ptrace_regset(child, request, addr, &kiov);
|
|
if (!ret)
|
|
ret = __put_user(kiov.iov_len, &uiov->iov_len);
|
|
break;
|
|
}
|
|
#endif
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct task_struct *ptrace_get_task_struct(pid_t pid)
|
|
{
|
|
struct task_struct *child;
|
|
|
|
rcu_read_lock();
|
|
child = find_task_by_vpid(pid);
|
|
if (child)
|
|
get_task_struct(child);
|
|
rcu_read_unlock();
|
|
|
|
if (!child)
|
|
return ERR_PTR(-ESRCH);
|
|
return child;
|
|
}
|
|
|
|
#ifndef arch_ptrace_attach
|
|
#define arch_ptrace_attach(child) do { } while (0)
|
|
#endif
|
|
|
|
SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
|
|
unsigned long, data)
|
|
{
|
|
struct task_struct *child;
|
|
long ret;
|
|
|
|
if (request == PTRACE_TRACEME) {
|
|
ret = ptrace_traceme();
|
|
if (!ret)
|
|
arch_ptrace_attach(current);
|
|
goto out;
|
|
}
|
|
|
|
child = ptrace_get_task_struct(pid);
|
|
if (IS_ERR(child)) {
|
|
ret = PTR_ERR(child);
|
|
goto out;
|
|
}
|
|
|
|
if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
|
|
ret = ptrace_attach(child, request, addr, data);
|
|
/*
|
|
* Some architectures need to do book-keeping after
|
|
* a ptrace attach.
|
|
*/
|
|
if (!ret)
|
|
arch_ptrace_attach(child);
|
|
goto out_put_task_struct;
|
|
}
|
|
|
|
ret = ptrace_check_attach(child, request == PTRACE_KILL ||
|
|
request == PTRACE_INTERRUPT);
|
|
if (ret < 0)
|
|
goto out_put_task_struct;
|
|
|
|
ret = arch_ptrace(child, request, addr, data);
|
|
if (ret || request != PTRACE_DETACH)
|
|
ptrace_unfreeze_traced(child);
|
|
|
|
out_put_task_struct:
|
|
put_task_struct(child);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
|
|
unsigned long data)
|
|
{
|
|
unsigned long tmp;
|
|
int copied;
|
|
|
|
copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0);
|
|
if (copied != sizeof(tmp))
|
|
return -EIO;
|
|
return put_user(tmp, (unsigned long __user *)data);
|
|
}
|
|
|
|
int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
|
|
unsigned long data)
|
|
{
|
|
int copied;
|
|
|
|
copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
|
|
return (copied == sizeof(data)) ? 0 : -EIO;
|
|
}
|
|
|
|
#if defined CONFIG_COMPAT
|
|
#include <linux/compat.h>
|
|
|
|
int compat_ptrace_request(struct task_struct *child, compat_long_t request,
|
|
compat_ulong_t addr, compat_ulong_t data)
|
|
{
|
|
compat_ulong_t __user *datap = compat_ptr(data);
|
|
compat_ulong_t word;
|
|
siginfo_t siginfo;
|
|
int ret;
|
|
|
|
switch (request) {
|
|
case PTRACE_PEEKTEXT:
|
|
case PTRACE_PEEKDATA:
|
|
ret = access_process_vm(child, addr, &word, sizeof(word), 0);
|
|
if (ret != sizeof(word))
|
|
ret = -EIO;
|
|
else
|
|
ret = put_user(word, datap);
|
|
break;
|
|
|
|
case PTRACE_POKETEXT:
|
|
case PTRACE_POKEDATA:
|
|
ret = access_process_vm(child, addr, &data, sizeof(data), 1);
|
|
ret = (ret != sizeof(data) ? -EIO : 0);
|
|
break;
|
|
|
|
case PTRACE_GETEVENTMSG:
|
|
ret = put_user((compat_ulong_t) child->ptrace_message, datap);
|
|
break;
|
|
|
|
case PTRACE_GETSIGINFO:
|
|
ret = ptrace_getsiginfo(child, &siginfo);
|
|
if (!ret)
|
|
ret = copy_siginfo_to_user32(
|
|
(struct compat_siginfo __user *) datap,
|
|
&siginfo);
|
|
break;
|
|
|
|
case PTRACE_SETSIGINFO:
|
|
memset(&siginfo, 0, sizeof siginfo);
|
|
if (copy_siginfo_from_user32(
|
|
&siginfo, (struct compat_siginfo __user *) datap))
|
|
ret = -EFAULT;
|
|
else
|
|
ret = ptrace_setsiginfo(child, &siginfo);
|
|
break;
|
|
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
|
|
case PTRACE_GETREGSET:
|
|
case PTRACE_SETREGSET:
|
|
{
|
|
struct iovec kiov;
|
|
struct compat_iovec __user *uiov =
|
|
(struct compat_iovec __user *) datap;
|
|
compat_uptr_t ptr;
|
|
compat_size_t len;
|
|
|
|
if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov)))
|
|
return -EFAULT;
|
|
|
|
if (__get_user(ptr, &uiov->iov_base) ||
|
|
__get_user(len, &uiov->iov_len))
|
|
return -EFAULT;
|
|
|
|
kiov.iov_base = compat_ptr(ptr);
|
|
kiov.iov_len = len;
|
|
|
|
ret = ptrace_regset(child, request, addr, &kiov);
|
|
if (!ret)
|
|
ret = __put_user(kiov.iov_len, &uiov->iov_len);
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
default:
|
|
ret = ptrace_request(child, request, addr, data);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
|
|
compat_long_t, addr, compat_long_t, data)
|
|
{
|
|
struct task_struct *child;
|
|
long ret;
|
|
|
|
if (request == PTRACE_TRACEME) {
|
|
ret = ptrace_traceme();
|
|
goto out;
|
|
}
|
|
|
|
child = ptrace_get_task_struct(pid);
|
|
if (IS_ERR(child)) {
|
|
ret = PTR_ERR(child);
|
|
goto out;
|
|
}
|
|
|
|
if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
|
|
ret = ptrace_attach(child, request, addr, data);
|
|
/*
|
|
* Some architectures need to do book-keeping after
|
|
* a ptrace attach.
|
|
*/
|
|
if (!ret)
|
|
arch_ptrace_attach(child);
|
|
goto out_put_task_struct;
|
|
}
|
|
|
|
ret = ptrace_check_attach(child, request == PTRACE_KILL ||
|
|
request == PTRACE_INTERRUPT);
|
|
if (!ret) {
|
|
ret = compat_arch_ptrace(child, request, addr, data);
|
|
if (ret || request != PTRACE_DETACH)
|
|
ptrace_unfreeze_traced(child);
|
|
}
|
|
|
|
out_put_task_struct:
|
|
put_task_struct(child);
|
|
out:
|
|
return ret;
|
|
}
|
|
#endif /* CONFIG_COMPAT */
|