Date: Mon, 11 Apr 2016 16:44:52 +0900
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
To: Alexander Potapenko <glider@google.com>
Cc: adech.fo@gmail.com, cl@linux.com, dvyukov@google.com,
        akpm@linux-foundation.org, ryabinin.a.a@gmail.com, rostedt@goodmis.org,
        kcc@google.com, kasan-dev@googlegroups.com,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH v7 5/7] mm, kasan: Stackdepot implementation. Enable
 stackdepot for SLAB
Message-ID: <20160411074452.GC26116@js1304-P5Q-DELUXE>
References: <cover.1457949315.git.glider@google.com>
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On Mon, Mar 14, 2016 at 11:43:43AM +0100, Alexander Potapenko wrote:
> +depot_stack_handle_t depot_save_stack(struct stack_trace *trace,
> +				    gfp_t alloc_flags)
> +{
> +	u32 hash;
> +	depot_stack_handle_t retval = 0;
> +	struct stack_record *found = NULL, **bucket;
> +	unsigned long flags;
> +	struct page *page = NULL;
> +	void *prealloc = NULL;
> +	bool *rec;
> +
> +	if (unlikely(trace->nr_entries == 0))
> +		goto fast_exit;
> +
> +	rec = this_cpu_ptr(&depot_recursion);
> +	/* Don't store the stack if we've been called recursively. */
> +	if (unlikely(*rec))
> +		goto fast_exit;
> +	*rec = true;
> +
> +	hash = hash_stack(trace->entries, trace->nr_entries);
> +	/* Bad luck, we won't store this stack. */
> +	if (hash == 0)
> +		goto exit;

Hello,

why is hash == 0 skipped?

Thanks.