Re: [PATCH 2/2] kdb: Call vkdb_printf() from vprintk_default() only when wanted

[Sergey Senozhatsky]

On (10/21/16 14:50), Petr Mladek wrote:
[..]
> diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> index d5e397315473..db73e33811e7 100644
> --- a/kernel/printk/printk.c
> +++ b/kernel/printk/printk.c
> @@ -1941,7 +1941,9 @@ int vprintk_default(const char *fmt, va_list args)
>       int r;
>  
>  #ifdef CONFIG_KGDB_KDB
> -     if (unlikely(kdb_trap_printk)) {
> +     /* Allow to pass printk() to kdb but avoid a recursion. */
> +     if (unlikely(kdb_trap_printk &&
> +                  kdb_printf_cpu != smp_processor_id())) {
                                        ^^^^^
                aren't we are in preemptible here?

        -ss

>               r = vkdb_printf(KDB_MSGSRC_PRINTK, fmt, args);
>               return r;