Re: [PATCH v2] printk/kdb: Redirect printk messages into kdb in any context

[Sergey Senozhatsky]

On (20/05/20 12:22), Petr Mladek wrote:
> kdb has to get messages on consoles even when the system is stopped.
> It uses kdb_printf() internally and calls console drivers on its own.
> 
> It uses a hack to reuse an existing code. It sets "kdb_trap_printk"
> global variable to redirect even the normal printk() into the
> kdb_printf() variant.
> 
> The variable "kdb_trap_printk" is checked in printk_default() and
> it is ignored when printk is redirected to printk_safe in NMI context.
> Solve this by moving the check into printk_func().
> 
> It is obvious that it is not fully safe. But it does not make things
> worse. The console drivers are already called in this context by
> db_printf() direct calls.
> 
> Reported-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
> Tested-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
> Signed-off-by: Petr Mladek <pmladek@xxxxxxxx>

Acked-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>

	-ss