linux-kernel - Re: [PATCH] lib: introduce strdup_from

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Message-ID: <4DE92AC0.1000806@freescale.com>
Date:	Fri, 3 Jun 2011 13:41:04 -0500
From:	Timur Tabi <timur@...escale.com>
To:	Alexey Dobriyan <adobriyan@...il.com>
CC:	<alan@...rguk.ukuu.org.uk>, <linux-kernel@...r.kernel.org>,
	<scottwood@...escale.com>, <akpm@...ux-foundation.org>
Subject: Re: [PATCH] lib: introduce strdup_from_user

Alexey Dobriyan wrote:
> The point is data should cross kernelspace/userspace boundary only once.

And my new version does that.  I'm just asking if you're okay with it.

Let me repost the whole function:

char *strdup_from_user(const char __user *ustr, size_t max)
{
	size_t len;
	char *str;

	str = kzalloc(max, GFP_KERNEL);
	if (!str)
		return ERR_PTR(-ENOMEM);

	if (copy_from_user(str, ustr, max - 1)) {
		kfree(str);
		return ERR_PTR(-EFAULT);
	}

	return krealloc(str, strlen(str) + 1, GFP_KERNEL);
}


-- 
Timur Tabi
Linux kernel developer at Freescale

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