Re: [PATCH 6/7] mm: kill vma flag VM_EXECUTABLE

[Oleg Nesterov <oleg@xxxxxxxxxx>]

On 04/02, Konstantin Khlebnikov wrote:
>
> In this patch I leave mm->exe_file lockless.
> After exec/fork we can change it only for current task and only if mm->mm_users == 1.
>
> something like this:
>
> task_lock(current);

OK, this protects against the race with get_task_mm()

> if (atomic_read(&current->mm->mm_users) == 1)

this means PR_SET_MM_EXE_FILE can fail simply because someone did
get_task_mm(). Or the caller is multithreaded.

> 	set_mm_exe_file(current->mm, new_file);

No, fput() can sleep.

Oleg.

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