Re: [RFC v3 PATCH 3/5] mm: refactor do_munmap() to extract the common part

From: Michal Hocko <mhocko@kernel.org>
To: Yang Shi <yang.shi@linux.alibaba.com>
Cc: willy@infradead.org, ldufour@linux.vnet.ibm.com,
	akpm@linux-foundation.org, peterz@infradead.org,
	mingo@redhat.com, acme@kernel.org,
	alexander.shishkin@linux.intel.com, jolsa@redhat.com,
	namhyung@kernel.org, tglx@linutronix.de, hpa@zytor.com,
	linux-mm@kvack.org, x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC v3 PATCH 3/5] mm: refactor do_munmap() to extract the common part
Date: Mon, 2 Jul 2018 15:42:26 +0200	[thread overview]
Message-ID: <20180702134226.GX19043@dhcp22.suse.cz> (raw)
In-Reply-To: <1530311985-31251-4-git-send-email-yang.shi@linux.alibaba.com>

On Sat 30-06-18 06:39:43, Yang Shi wrote:
> Introduces two new helper functions:
>   * munmap_addr_sanity()
>   * munmap_lookup_vma()
> 
> They will be used by do_munmap() and the new do_munmap with zapping
> large mapping early in the later patch.
> 
> There is no functional change, just code refactor.

There are whitespace changes which make the code much harder to review
than necessary.
> +static inline bool munmap_addr_sanity(unsigned long start, size_t len)
>  {
> -	unsigned long end;
> -	struct vm_area_struct *vma, *prev, *last;
> +	if ((offset_in_page(start)) || start > TASK_SIZE || len > TASK_SIZE - start)
> +		return false;
>  
> -	if ((offset_in_page(start)) || start > TASK_SIZE || len > TASK_SIZE-start)
> -		return -EINVAL;

e.g. here.
-- 
Michal Hocko
SUSE Labs