Re: [PATCH] workqueue: fix null-ptr-deref on __alloc_workqueue() error

[Sergey Senozhatsky <senozhatsky@chromium.org>]

Hi Matthew,

On (24/08/15 16:24), Matthew Brost wrote:
[..]
> diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
> index 8ccbf510880b..5e818eae092d 100644
> --- a/include/linux/workqueue.h
> +++ b/include/linux/workqueue.h
> @@ -534,7 +534,7 @@ alloc_workqueue_lockdep_map(const char *fmt, unsigned int flags, int max_active,
>   * @fmt: printf format for the name of the workqueue
>   * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
>   * @lockdep_map: user-defined lockdep_map
> - * @args: args for @fmt
> + * @...: args for @fmt
>   *
>   * Same as alloc_ordered_workqueue but with the a user-define lockdep_map.
>   * Useful for workqueues created with the same purpose and to avoid leaking a
> @@ -543,20 +543,9 @@ alloc_workqueue_lockdep_map(const char *fmt, unsigned int flags, int max_active,
>   * RETURNS:
>   * Pointer to the allocated workqueue on success, %NULL on failure.
>   */
> -__printf(1, 4) static inline struct workqueue_struct *
> -alloc_ordered_workqueue_lockdep_map(const char *fmt, unsigned int flags,
> -                                   struct lockdep_map *lockdep_map, ...)
> -{
> -       struct workqueue_struct *wq;
> -       va_list args;
> -
> -       va_start(args, lockdep_map);
> -       wq = alloc_workqueue_lockdep_map(fmt, WQ_UNBOUND | __WQ_ORDERED | flags,
> -                                        1, lockdep_map, args);
> -       va_end(args);
> +#define alloc_ordered_workqueue_lockdep_map(fmt, flags, lockdep_map, args...)  \
> +       alloc_workqueue_lockdep_map(fmt, WQ_UNBOUND | __WQ_ORDERED | (flags), 1, lockdep_map, ##args)
> 
> -       return wq;
> -}
>  #endif

Oh, I haven't checked the workqueue header.  Yes, you are right.
A macro should work.


Tejun, how do you plan to handle this?  Would it be possible to
drop current series from your tree so that Matthew can send an
updated version (with all the fixes squashed)?