Re: [PATCH] kdb: Avoid using dbg_io_ops until it is initialized

Jason Wessel
2012-03-20T18:42:18Z

On 09/21/2011 03:19 PM, Tim Bird wrote:
> This fixes a bug with setting a breakpoint during kdb initialization
> (from kdb_cmds). Any call to kdb_printf() before the initialization
> of the kgdboc serial console driver (which happens much later during
> bootup than kdb_init), results in kernel panic due to the use of
> dbg_io_ops before it is initialized.

I added this patch to the merge queue for the 3.4 kernel.

In the test and review of this patch, I thought there might be another
race condition with kdb pager, but this is not the case. The run time
validation shows that the kdb pager can only get activated by entering
and configuring the kdb shell and it is turned off on exit, so we are
all set and no further changes are needed.

Thanks,
Jason.