Re: [PATCH v7 00/43] Add KernelMemorySanitizer infrastructure

[Andrew Morton]

On Thu, 15 Sep 2022 14:05:51 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> 
> For "kmsan: add KMSAN runtime core":
> 
> ...
>
> @@ -219,23 +212,22 @@ depot_stack_handle_t kmsan_internal_chai
>  	 * Make sure we have enough spare bits in @id to hold the UAF bit and
>  	 * the chain depth.
>  	 */
> -	BUILD_BUG_ON((1 << STACK_DEPOT_EXTRA_BITS) <= (MAX_CHAIN_DEPTH << 1));
> +	BUILD_BUG_ON(
> +		(1 << STACK_DEPOT_EXTRA_BITS) <= (KMSAN_MAX_ORIGIN_DEPTH << 1));
>  
>  	extra_bits = stack_depot_get_extra_bits(id);
>  	depth = kmsan_depth_from_eb(extra_bits);
>  	uaf = kmsan_uaf_from_eb(extra_bits);
>  
> -	if (depth >= MAX_CHAIN_DEPTH) {
> -		static atomic_long_t kmsan_skipped_origins;
> -		long skipped = atomic_long_inc_return(&kmsan_skipped_origins);
> -
> -		if (skipped % NUM_SKIPPED_TO_WARN == 0) {
> -			pr_warn("not chained %ld origins\n", skipped);
> -			dump_stack();
> -			kmsan_print_origin(id);
> -		}

Wouldn't it be neat if printk_ratelimited() returned true if it printed
something.

But you deleted this user of that neatness anyway ;)