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![Peter Zijlstra](/assets/img/avatar_default.png)
Rewrite the core freezer to behave better wrt thawing and be simpler in general. By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is ensured frozen tasks stay frozen until thawed and don't randomly wake up early, as is currently possible. As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up two PF_flags (yay!). Specifically; the current scheme works a little like: freezer_do_not_count(); schedule(); freezer_count(); And either the task is blocked, or it lands in try_to_freezer() through freezer_count(). Now, when it is blocked, the freezer considers it frozen and continues. However, on thawing, once pm_freezing is cleared, freezer_count() stops working, and any random/spurious wakeup will let a task run before its time. That is, thawing tries to thaw things in explicit order; kernel threads and workqueues before doing bringing SMP back before userspace etc.. However due to the above mentioned races it is entirely possible for userspace tasks to thaw (by accident) before SMP is back. This can be a fatal problem in asymmetric ISA architectures (eg ARMv9) where the userspace task requires a special CPU to run. As said; replace this with a special task state TASK_FROZEN and add the following state transitions: TASK_FREEZABLE -> TASK_FROZEN __TASK_STOPPED -> TASK_FROZEN __TASK_TRACED -> TASK_FROZEN The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL (IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state is already required to deal with spurious wakeups and the freezer causes one such when thawing the task (since the original state is lost). The special __TASK_{STOPPED,TRACED} states *can* be restored since their canonical state is in ->jobctl. With this, frozen tasks need an explicit TASK_FROZEN wakeup and are free of undue (early / spurious) wakeups. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org
1443 lines
37 KiB
C
1443 lines
37 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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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/sched/mm.h>
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#include <linux/sched/coredump.h>
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#include <linux/sched/task.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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#include <linux/sched/signal.h>
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#include <linux/minmax.h>
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#include <asm/syscall.h> /* for syscall_get_* */
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/*
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* Access another process' address space via ptrace.
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* Source/target buffer must be kernel space,
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* Do not walk the page table directly, use get_user_pages
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*/
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int ptrace_access_vm(struct task_struct *tsk, unsigned long addr,
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void *buf, int len, unsigned int gup_flags)
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{
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struct mm_struct *mm;
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int ret;
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mm = get_task_mm(tsk);
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if (!mm)
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return 0;
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if (!tsk->ptrace ||
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(current != tsk->parent) ||
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((get_dumpable(mm) != SUID_DUMP_USER) &&
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!ptracer_capable(tsk, mm->user_ns))) {
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mmput(mm);
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return 0;
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}
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ret = __access_remote_vm(mm, addr, buf, len, gup_flags);
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mmput(mm);
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return ret;
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}
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void __ptrace_link(struct task_struct *child, struct task_struct *new_parent,
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const struct cred *ptracer_cred)
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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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child->ptracer_cred = get_cred(ptracer_cred);
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}
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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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static void ptrace_link(struct task_struct *child, struct task_struct *new_parent)
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{
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__ptrace_link(child, new_parent, current_cred());
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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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const struct cred *old_cred;
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BUG_ON(!child->ptrace);
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clear_task_syscall_work(child, SYSCALL_TRACE);
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#if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU)
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clear_task_syscall_work(child, SYSCALL_EMU);
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#endif
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child->parent = child->real_parent;
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list_del_init(&child->ptrace_entry);
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old_cred = child->ptracer_cred;
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child->ptracer_cred = NULL;
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put_cred(old_cred);
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spin_lock(&child->sighand->siglock);
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child->ptrace = 0;
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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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static bool looks_like_a_spurious_pid(struct task_struct *task)
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{
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if (task->exit_code != ((PTRACE_EVENT_EXEC << 8) | SIGTRAP))
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return false;
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if (task_pid_vnr(task) == task->ptrace_message)
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return false;
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/*
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* The tracee changed its pid but the PTRACE_EVENT_EXEC event
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* was not wait()'ed, most probably debugger targets the old
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* leader which was destroyed in de_thread().
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*/
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return true;
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}
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/*
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* Ensure that nothing can wake it up, even SIGKILL
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*
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* A task is switched to this state while a ptrace operation is in progress;
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* such that the ptrace operation is uninterruptible.
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*/
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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) && !looks_like_a_spurious_pid(task) &&
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!__fatal_signal_pending(task)) {
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task->jobctl |= JOBCTL_PTRACE_FROZEN;
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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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unsigned long flags;
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/*
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* The child may be awake and may have cleared
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* JOBCTL_PTRACE_FROZEN (see ptrace_resume). The child will
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* not set JOBCTL_PTRACE_FROZEN or enter __TASK_TRACED anew.
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*/
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if (lock_task_sighand(task, &flags)) {
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task->jobctl &= ~JOBCTL_PTRACE_FROZEN;
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if (__fatal_signal_pending(task)) {
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task->jobctl &= ~JOBCTL_TRACED;
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wake_up_state(task, __TASK_TRACED);
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}
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unlock_task_sighand(task, &flags);
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}
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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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/*
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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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WARN_ON_ONCE(!wait_task_inactive(child, __TASK_TRACED|TASK_FROZEN)))
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ret = -ESRCH;
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return ret;
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}
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static bool 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 ns_capable_noaudit(ns, CAP_SYS_PTRACE);
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return ns_capable(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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struct mm_struct *mm;
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kuid_t caller_uid;
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kgid_t caller_gid;
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if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
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WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
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return -EPERM;
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}
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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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/* 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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if (mode & PTRACE_MODE_FSCREDS) {
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caller_uid = cred->fsuid;
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caller_gid = cred->fsgid;
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} else {
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/*
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* Using the euid would make more sense here, but something
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* in userland might rely on the old behavior, and this
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* shouldn't be a security problem since
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* PTRACE_MODE_REALCREDS implies that the caller explicitly
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* used a syscall that requests access to another process
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* (and not a filesystem syscall to procfs).
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*/
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caller_uid = cred->uid;
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caller_gid = cred->gid;
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}
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tcred = __task_cred(task);
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if (uid_eq(caller_uid, tcred->euid) &&
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uid_eq(caller_uid, tcred->suid) &&
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uid_eq(caller_uid, tcred->uid) &&
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gid_eq(caller_gid, tcred->egid) &&
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gid_eq(caller_gid, tcred->sgid) &&
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gid_eq(caller_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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/*
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* If a task drops privileges and becomes nondumpable (through a syscall
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* like setresuid()) while we are trying to access it, we must ensure
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* that the dumpability is read after the credentials; otherwise,
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* we may be able to attach to a task that we shouldn't be able to
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* attach to (as if the task had dropped privileges without becoming
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* nondumpable).
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* Pairs with a write barrier in commit_creds().
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*/
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smp_rmb();
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mm = task->mm;
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if (mm &&
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((get_dumpable(mm) != SUID_DUMP_USER) &&
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!ptrace_has_cap(mm->user_ns, mode)))
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return -EPERM;
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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 check_ptrace_options(unsigned long data)
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{
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if (data & ~(unsigned long)PTRACE_O_MASK)
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return -EINVAL;
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if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) {
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if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) ||
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!IS_ENABLED(CONFIG_SECCOMP))
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return -EINVAL;
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|
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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|
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if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED ||
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current->ptrace & PT_SUSPEND_SECCOMP)
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return -EPERM;
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}
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return 0;
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}
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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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/*
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* This duplicates the check in check_ptrace_options() because
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* ptrace_attach() and ptrace_setoptions() have historically
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* used different error codes for unknown ptrace options.
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*/
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if (flags & ~(unsigned long)PTRACE_O_MASK)
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goto out;
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retval = check_ptrace_options(flags);
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if (retval)
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return retval;
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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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|
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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;
|
|
|
|
/*
|
|
* 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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retval = -ERESTARTNOINTR;
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|
if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
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goto out;
|
|
|
|
task_lock(task);
|
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retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
|
|
task_unlock(task);
|
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if (retval)
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goto unlock_creds;
|
|
|
|
write_lock_irq(&tasklist_lock);
|
|
retval = -EPERM;
|
|
if (unlikely(task->exit_state))
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|
goto unlock_tasklist;
|
|
if (task->ptrace)
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|
goto unlock_tasklist;
|
|
|
|
task->ptrace = flags;
|
|
|
|
ptrace_link(task, current);
|
|
|
|
/* SEIZE doesn't trap tracee on attach */
|
|
if (!seize)
|
|
send_sig_info(SIGSTOP, SEND_SIG_PRIV, 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)) {
|
|
task->jobctl &= ~JOBCTL_STOPPED;
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* 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_PRIV, 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 = 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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
static int ptrace_setoptions(struct task_struct *child, unsigned long data)
|
|
{
|
|
unsigned flags;
|
|
int ret;
|
|
|
|
ret = check_ptrace_options(data);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* 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, kernel_siginfo_t *info)
|
|
{
|
|
unsigned long flags;
|
|
int error = -ESRCH;
|
|
|
|
if (lock_task_sighand(child, &flags)) {
|
|
error = -EINVAL;
|
|
if (likely(child->last_siginfo != NULL)) {
|
|
copy_siginfo(info, child->last_siginfo);
|
|
error = 0;
|
|
}
|
|
unlock_task_sighand(child, &flags);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info)
|
|
{
|
|
unsigned long flags;
|
|
int error = -ESRCH;
|
|
|
|
if (lock_task_sighand(child, &flags)) {
|
|
error = -EINVAL;
|
|
if (likely(child->last_siginfo != NULL)) {
|
|
copy_siginfo(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;
|
|
|
|
/* Ensure arg.off fits in an unsigned long */
|
|
if (arg.off > ULONG_MAX)
|
|
return 0;
|
|
|
|
if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
|
|
pending = &child->signal->shared_pending;
|
|
else
|
|
pending = &child->pending;
|
|
|
|
for (i = 0; i < arg.nr; ) {
|
|
kernel_siginfo_t info;
|
|
unsigned long off = arg.off + i;
|
|
bool found = false;
|
|
|
|
spin_lock_irq(&child->sighand->siglock);
|
|
list_for_each_entry(q, &pending->list, list) {
|
|
if (!off--) {
|
|
found = true;
|
|
copy_siginfo(&info, &q->info);
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock_irq(&child->sighand->siglock);
|
|
|
|
if (!found) /* 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;
|
|
}
|
|
|
|
#ifdef CONFIG_RSEQ
|
|
static long ptrace_get_rseq_configuration(struct task_struct *task,
|
|
unsigned long size, void __user *data)
|
|
{
|
|
struct ptrace_rseq_configuration conf = {
|
|
.rseq_abi_pointer = (u64)(uintptr_t)task->rseq,
|
|
.rseq_abi_size = sizeof(*task->rseq),
|
|
.signature = task->rseq_sig,
|
|
.flags = 0,
|
|
};
|
|
|
|
size = min_t(unsigned long, size, sizeof(conf));
|
|
if (copy_to_user(data, &conf, size))
|
|
return -EFAULT;
|
|
return sizeof(conf);
|
|
}
|
|
#endif
|
|
|
|
#define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
|
|
|
|
#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_task_syscall_work(child, SYSCALL_TRACE);
|
|
else
|
|
clear_task_syscall_work(child, SYSCALL_TRACE);
|
|
|
|
#if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU)
|
|
if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
|
|
set_task_syscall_work(child, SYSCALL_EMU);
|
|
else
|
|
clear_task_syscall_work(child, 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);
|
|
}
|
|
|
|
/*
|
|
* Change ->exit_code and ->state under siglock to avoid the race
|
|
* with wait_task_stopped() in between; a non-zero ->exit_code will
|
|
* wrongly look like another report from tracee.
|
|
*
|
|
* Note that we need siglock even if ->exit_code == data and/or this
|
|
* status was not reported yet, the new status must not be cleared by
|
|
* wait_task_stopped() after resume.
|
|
*/
|
|
spin_lock_irq(&child->sighand->siglock);
|
|
child->exit_code = data;
|
|
child->jobctl &= ~JOBCTL_TRACED;
|
|
wake_up_state(child, __TASK_TRACED);
|
|
spin_unlock_irq(&child->sighand->siglock);
|
|
|
|
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);
|
|
|
|
static unsigned long
|
|
ptrace_get_syscall_info_entry(struct task_struct *child, struct pt_regs *regs,
|
|
struct ptrace_syscall_info *info)
|
|
{
|
|
unsigned long args[ARRAY_SIZE(info->entry.args)];
|
|
int i;
|
|
|
|
info->op = PTRACE_SYSCALL_INFO_ENTRY;
|
|
info->entry.nr = syscall_get_nr(child, regs);
|
|
syscall_get_arguments(child, regs, args);
|
|
for (i = 0; i < ARRAY_SIZE(args); i++)
|
|
info->entry.args[i] = args[i];
|
|
|
|
/* args is the last field in struct ptrace_syscall_info.entry */
|
|
return offsetofend(struct ptrace_syscall_info, entry.args);
|
|
}
|
|
|
|
static unsigned long
|
|
ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs,
|
|
struct ptrace_syscall_info *info)
|
|
{
|
|
/*
|
|
* As struct ptrace_syscall_info.entry is currently a subset
|
|
* of struct ptrace_syscall_info.seccomp, it makes sense to
|
|
* initialize that subset using ptrace_get_syscall_info_entry().
|
|
* This can be reconsidered in the future if these structures
|
|
* diverge significantly enough.
|
|
*/
|
|
ptrace_get_syscall_info_entry(child, regs, info);
|
|
info->op = PTRACE_SYSCALL_INFO_SECCOMP;
|
|
info->seccomp.ret_data = child->ptrace_message;
|
|
|
|
/* ret_data is the last field in struct ptrace_syscall_info.seccomp */
|
|
return offsetofend(struct ptrace_syscall_info, seccomp.ret_data);
|
|
}
|
|
|
|
static unsigned long
|
|
ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs,
|
|
struct ptrace_syscall_info *info)
|
|
{
|
|
info->op = PTRACE_SYSCALL_INFO_EXIT;
|
|
info->exit.rval = syscall_get_error(child, regs);
|
|
info->exit.is_error = !!info->exit.rval;
|
|
if (!info->exit.is_error)
|
|
info->exit.rval = syscall_get_return_value(child, regs);
|
|
|
|
/* is_error is the last field in struct ptrace_syscall_info.exit */
|
|
return offsetofend(struct ptrace_syscall_info, exit.is_error);
|
|
}
|
|
|
|
static int
|
|
ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size,
|
|
void __user *datavp)
|
|
{
|
|
struct pt_regs *regs = task_pt_regs(child);
|
|
struct ptrace_syscall_info info = {
|
|
.op = PTRACE_SYSCALL_INFO_NONE,
|
|
.arch = syscall_get_arch(child),
|
|
.instruction_pointer = instruction_pointer(regs),
|
|
.stack_pointer = user_stack_pointer(regs),
|
|
};
|
|
unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry);
|
|
unsigned long write_size;
|
|
|
|
/*
|
|
* This does not need lock_task_sighand() to access
|
|
* child->last_siginfo because ptrace_freeze_traced()
|
|
* called earlier by ptrace_check_attach() ensures that
|
|
* the tracee cannot go away and clear its last_siginfo.
|
|
*/
|
|
switch (child->last_siginfo ? child->last_siginfo->si_code : 0) {
|
|
case SIGTRAP | 0x80:
|
|
switch (child->ptrace_message) {
|
|
case PTRACE_EVENTMSG_SYSCALL_ENTRY:
|
|
actual_size = ptrace_get_syscall_info_entry(child, regs,
|
|
&info);
|
|
break;
|
|
case PTRACE_EVENTMSG_SYSCALL_EXIT:
|
|
actual_size = ptrace_get_syscall_info_exit(child, regs,
|
|
&info);
|
|
break;
|
|
}
|
|
break;
|
|
case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8):
|
|
actual_size = ptrace_get_syscall_info_seccomp(child, regs,
|
|
&info);
|
|
break;
|
|
}
|
|
|
|
write_size = min(actual_size, user_size);
|
|
return copy_to_user(datavp, &info, write_size) ? -EFAULT : actual_size;
|
|
}
|
|
#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
|
|
|
|
int ptrace_request(struct task_struct *child, long request,
|
|
unsigned long addr, unsigned long data)
|
|
{
|
|
bool seized = child->ptrace & PT_SEIZED;
|
|
int ret = -EIO;
|
|
kernel_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:
|
|
ret = copy_siginfo_from_user(&siginfo, datavp);
|
|
if (!ret)
|
|
ret = ptrace_setsiginfo(child, &siginfo);
|
|
break;
|
|
|
|
case PTRACE_GETSIGMASK: {
|
|
sigset_t *mask;
|
|
|
|
if (addr != sizeof(sigset_t)) {
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
if (test_tsk_restore_sigmask(child))
|
|
mask = &child->saved_sigmask;
|
|
else
|
|
mask = &child->blocked;
|
|
|
|
if (copy_to_user(datavp, mask, 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);
|
|
|
|
clear_tsk_restore_sigmask(child);
|
|
|
|
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
|
|
|
|
case PTRACE_SINGLESTEP:
|
|
#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:
|
|
send_sig_info(SIGKILL, SEND_SIG_NOINFO, child);
|
|
return 0;
|
|
|
|
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
|
|
case PTRACE_GETREGSET:
|
|
case PTRACE_SETREGSET: {
|
|
struct iovec kiov;
|
|
struct iovec __user *uiov = datavp;
|
|
|
|
if (!access_ok(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;
|
|
}
|
|
|
|
case PTRACE_GET_SYSCALL_INFO:
|
|
ret = ptrace_get_syscall_info(child, addr, datavp);
|
|
break;
|
|
#endif
|
|
|
|
case PTRACE_SECCOMP_GET_FILTER:
|
|
ret = seccomp_get_filter(child, addr, datavp);
|
|
break;
|
|
|
|
case PTRACE_SECCOMP_GET_METADATA:
|
|
ret = seccomp_get_metadata(child, addr, datavp);
|
|
break;
|
|
|
|
#ifdef CONFIG_RSEQ
|
|
case PTRACE_GET_RSEQ_CONFIGURATION:
|
|
ret = ptrace_get_rseq_configuration(child, addr, datavp);
|
|
break;
|
|
#endif
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
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();
|
|
goto out;
|
|
}
|
|
|
|
child = find_get_task_by_vpid(pid);
|
|
if (!child) {
|
|
ret = -ESRCH;
|
|
goto out;
|
|
}
|
|
|
|
if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
|
|
ret = ptrace_attach(child, request, addr, data);
|
|
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 = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE);
|
|
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 = ptrace_access_vm(tsk, addr, &data, sizeof(data),
|
|
FOLL_FORCE | FOLL_WRITE);
|
|
return (copied == sizeof(data)) ? 0 : -EIO;
|
|
}
|
|
|
|
#if defined CONFIG_COMPAT
|
|
|
|
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;
|
|
kernel_siginfo_t siginfo;
|
|
int ret;
|
|
|
|
switch (request) {
|
|
case PTRACE_PEEKTEXT:
|
|
case PTRACE_PEEKDATA:
|
|
ret = ptrace_access_vm(child, addr, &word, sizeof(word),
|
|
FOLL_FORCE);
|
|
if (ret != sizeof(word))
|
|
ret = -EIO;
|
|
else
|
|
ret = put_user(word, datap);
|
|
break;
|
|
|
|
case PTRACE_POKETEXT:
|
|
case PTRACE_POKEDATA:
|
|
ret = ptrace_access_vm(child, addr, &data, sizeof(data),
|
|
FOLL_FORCE | FOLL_WRITE);
|
|
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:
|
|
ret = copy_siginfo_from_user32(
|
|
&siginfo, (struct compat_siginfo __user *) datap);
|
|
if (!ret)
|
|
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(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 = find_get_task_by_vpid(pid);
|
|
if (!child) {
|
|
ret = -ESRCH;
|
|
goto out;
|
|
}
|
|
|
|
if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
|
|
ret = ptrace_attach(child, request, addr, data);
|
|
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 */
|