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From: Christopher Lameter <cl@linux.com>
To: Shyam Saini <mayhs11saini@gmail.com>
Cc: linux-mm@kvack.org, kernel-hardening@lists.openwall.com,
	 Matthew Wilcox <willy@infradead.org>,
	Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH] slab: Redefine ZERO_SIZE_PTR to include ERR_PTR range
Date: Thu, 10 Oct 2019 14:22:40 +0000 (UTC)	[thread overview]
Message-ID: <alpine.DEB.2.21.1910101418500.27284@www.lameter.com> (raw)
In-Reply-To: <20191010103151.7708-1-mayhs11saini@gmail.com>

On Thu, 10 Oct 2019, Shyam Saini wrote:

> This will help error related to ERR_PTR stand out better.

Maybe make ZERO_SIZE_PTR an ERRNO value instead? Then allow ERR_PTRs to be
used instead of ZERO_SIZE_PTRs

ERRNO_ZERO_OBJECT

or something like that?

>   */
> -#define ZERO_SIZE_PTR ((void *)16)

#define ZERO_SIZE_PTR ((void *)-ERRNO_ZERO_OBJECT)

> +
> +#define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) - 1 >= \
> +		(unsigned long)ZERO_SIZE_PTR - 1)

And call this something different?



       reply	other threads:[~2019-10-10 14:22 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20191010103151.7708-1-mayhs11saini@gmail.com>
2019-10-10 14:22 ` Christopher Lameter [this message]
2019-10-10 17:44   ` [PATCH] slab: Redefine ZERO_SIZE_PTR to include ERR_PTR range Matthew Wilcox
2019-10-10 18:35     ` Christopher Lameter
2019-10-20  6:06     ` Shyam Saini
2019-10-20 15:38 ` Jann Horn

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