diff options
| -rw-r--r-- | fs/coredump.c | 8 | ||||
| -rw-r--r-- | include/linux/sched.h | 1 | ||||
| -rw-r--r-- | kernel/exit.c | 19 | ||||
| -rw-r--r-- | kernel/fork.c | 3 | ||||
| -rw-r--r-- | kernel/signal.c | 27 | ||||
| -rw-r--r-- | mm/oom_kill.c | 2 |
6 files changed, 20 insertions, 40 deletions
diff --git a/fs/coredump.c b/fs/coredump.c index 5e0e08a7fb9b..d576287fb88b 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -359,7 +359,7 @@ static int zap_process(struct task_struct *start, int exit_code, int flags) for_each_thread(start, t) { task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); - if (t != current && t->mm) { + if (t != current && !(t->flags & PF_POSTCOREDUMP)) { sigaddset(&t->pending.signal, SIGKILL); signal_wake_up(t, 1); nr++; @@ -404,8 +404,8 @@ static int zap_threads(struct task_struct *tsk, struct mm_struct *mm, * * do_exit: * The caller holds mm->mmap_lock. This means that the task which - * uses this mm can't pass coredump_exit_mm(), so it can't exit or - * clear its ->mm. + * uses this mm can't pass coredump_task_exit(), so it can't exit + * or clear its ->mm. * * de_thread: * It does list_replace_rcu(&leader->tasks, ¤t->tasks), @@ -500,7 +500,7 @@ static void coredump_finish(struct mm_struct *mm, bool core_dumped) next = curr->next; task = curr->task; /* - * see coredump_exit_mm(), curr->task must not see + * see coredump_task_exit(), curr->task must not see * ->task == NULL before we read ->next. */ smp_mb(); diff --git a/include/linux/sched.h b/include/linux/sched.h index e12b524426b0..f3741f23935e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1664,6 +1664,7 @@ extern struct pid *cad_pid; #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ #define PF_IDLE 0x00000002 /* I am an IDLE thread */ #define PF_EXITING 0x00000004 /* Getting shut down */ +#define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ diff --git a/kernel/exit.c b/kernel/exit.c index cb1619d8fd64..774e6b5061b8 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -339,23 +339,29 @@ kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent) } } -static void coredump_exit_mm(struct mm_struct *mm) +static void coredump_task_exit(struct task_struct *tsk) { struct core_state *core_state; + struct mm_struct *mm; + + mm = tsk->mm; + if (!mm) + return; /* * Serialize with any possible pending coredump. * We must hold mmap_lock around checking core_state - * and clearing tsk->mm. The core-inducing thread + * and setting PF_POSTCOREDUMP. The core-inducing thread * will increment ->nr_threads for each thread in the - * group with ->mm != NULL. + * group without PF_POSTCOREDUMP set. */ + mmap_read_lock(mm); + tsk->flags |= PF_POSTCOREDUMP; core_state = mm->core_state; + mmap_read_unlock(mm); if (core_state) { struct core_thread self; - mmap_read_unlock(mm); - self.task = current; if (self.task->flags & PF_SIGNALED) self.next = xchg(&core_state->dumper.next, &self); @@ -375,7 +381,6 @@ static void coredump_exit_mm(struct mm_struct *mm) freezable_schedule(); } __set_current_state(TASK_RUNNING); - mmap_read_lock(mm); } } @@ -480,7 +485,6 @@ static void exit_mm(void) return; sync_mm_rss(mm); mmap_read_lock(mm); - coredump_exit_mm(mm); mmgrab(mm); BUG_ON(mm != current->active_mm); /* more a memory barrier than a real lock */ @@ -768,6 +772,7 @@ void __noreturn do_exit(long code) profile_task_exit(tsk); kcov_task_exit(tsk); + coredump_task_exit(tsk); ptrace_event(PTRACE_EVENT_EXIT, code); validate_creds_for_do_exit(tsk); diff --git a/kernel/fork.c b/kernel/fork.c index 38681ad44c76..9bd9f2da9e41 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1392,8 +1392,7 @@ static void mm_release(struct task_struct *tsk, struct mm_struct *mm) * purposes. */ if (tsk->clear_child_tid) { - if (!(tsk->signal->flags & SIGNAL_GROUP_COREDUMP) && - atomic_read(&mm->mm_users) > 1) { + if (atomic_read(&mm->mm_users) > 1) { /* * We don't check the error code - if userspace has * not set up a proper pointer then tough luck. diff --git a/kernel/signal.c b/kernel/signal.c index c9759ff2cb43..b0db80acc6ef 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2158,31 +2158,6 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, spin_unlock_irqrestore(&sighand->siglock, flags); } -static inline bool may_ptrace_stop(void) -{ - if (!likely(current->ptrace)) - return false; - /* - * Are we in the middle of do_coredump? - * If so and our tracer is also part of the coredump stopping - * is a deadlock situation, and pointless because our tracer - * is dead so don't allow us to stop. - * If SIGKILL was already sent before the caller unlocked - * ->siglock we must see ->core_state != NULL. Otherwise it - * is safe to enter schedule(). - * - * This is almost outdated, a task with the pending SIGKILL can't - * block in TASK_TRACED. But PTRACE_EVENT_EXIT can be reported - * after SIGKILL was already dequeued. - */ - if (unlikely(current->mm->core_state) && - unlikely(current->mm == current->parent->mm)) - return false; - - return true; -} - - /* * This must be called with current->sighand->siglock held. * @@ -2263,7 +2238,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t spin_unlock_irq(¤t->sighand->siglock); read_lock(&tasklist_lock); - if (may_ptrace_stop()) { + if (likely(current->ptrace)) { /* * Notify parents of the stop. * diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 295c8bdfd6c8..7877c755ab37 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -788,7 +788,7 @@ static inline bool __task_will_free_mem(struct task_struct *task) /* * A coredumping process may sleep for an extended period in - * coredump_exit_mm(), so the oom killer cannot assume that + * coredump_task_exit(), so the oom killer cannot assume that * the process will promptly exit and release memory. */ if (sig->flags & SIGNAL_GROUP_COREDUMP) |