Re: [PATCH] taint on lockdep warning with new TAINT_LOCKDEP

[Ingo Molnar <mingo@kernel.org>]

* Slava Pestov <sp@datera.io> wrote:

> This helps when writing automated tests, since they can fail the
> test if the kernel was tainted instead of manually scraping dmesg
> for interesting strings.
> 
> Signed-off-by: Slava Pestov <sp@daterainc.com>
> ---
>  include/linux/kernel.h   |  1 +
>  kernel/locking/lockdep.c | 31 +++++++++++++++++++++++++++++++
>  kernel/panic.c           |  2 ++
>  3 files changed, 34 insertions(+)
> 
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> index 5449d2f..c46e24e 100644
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -471,6 +471,7 @@ extern enum system_states {
>  #define TAINT_OOT_MODULE		12
>  #define TAINT_UNSIGNED_MODULE		13
>  #define TAINT_SOFTLOCKUP		14
> +#define TAINT_LOCKDEP			15
>  
>  extern const char hex_asc[];
>  #define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
> diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
> index 88d0d44..4916a32 100644
> --- a/kernel/locking/lockdep.c
> +++ b/kernel/locking/lockdep.c
> @@ -382,6 +382,8 @@ static unsigned long stack_trace[MAX_STACK_TRACE_ENTRIES];
>  
>  static void print_lockdep_off(const char *bug_msg)
>  {
> +	add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);

> +		add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);

> +	add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);

> +	add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);

> +	add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);

> +	add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);
>  
> +	add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);

> +	add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);

> +	add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);

> +	add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);

> +	add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);

> +	add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);

> +		add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);

> +	add_taint(TAINT_LOCKDEP, LOCKDEP_NOW_UNRELIABLE);

If only we had a function that turns lockdep off in a 
single place, instead of having to crap all over lockdep.c? 
;-)

Thanks,

	Ingo