From mboxrd@z Thu Jan  1 00:00:00 1970
From: catalin.marinas@arm.com (Catalin Marinas)
Date: Wed, 22 Jan 2014 17:39:28 +0000
Subject: [PATCH 2/6] arm64: Add function to create identity mappings
In-Reply-To: <1389392950-22457-3-git-send-email-msalter@redhat.com>
References: <1389392950-22457-1-git-send-email-msalter@redhat.com>
 <1389392950-22457-3-git-send-email-msalter@redhat.com>
Message-ID: <20140122173927.GE8065@arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Fri, Jan 10, 2014 at 10:29:06PM +0000, Mark Salter wrote:
> +void __init create_id_mapping(phys_addr_t addr, phys_addr_t size)
> +{
> +	pgd_t *pgd = &idmap_pg_dir[pgd_index(addr)];
> +
> +	if (pgd >= &idmap_pg_dir[ARRAY_SIZE(idmap_pg_dir)]) {
> +		pr_warn("BUG: not creating id mapping for 0x%016llx\n", addr);
> +		return;
> +	}

The condition above is always false since pgd_index() already ands the
index with (PTRS_PER_PGD - 1). Better check addr against something like
(PTRS_PER_PGD * PGDIR_SIZE) (for clarity, you could do other shifts,
doesn't really matter).

-- 
Catalin