linux-kernel - Re: [PATCH v2 09/19] ARM: at91: make sdram/ddr register base soc independent

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 23 Feb 2012 09:33:02 +1100
From:	Ryan Mallon <rmallon@...il.com>
To:	Nicolas Ferre <nicolas.ferre@...el.com>
CC:	plagnioj@...osoft.com, linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org, linux@....linux.org.uk
Subject: Re: [PATCH v2 09/19] ARM: at91: make sdram/ddr register base soc
 independent

On 22/02/12 20:39, Nicolas Ferre wrote:

> From: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@...osoft.com>
> 
> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@...osoft.com>
> Acked-by: Nicolas Ferre <nicolas.ferre@...el.com>
> ---

<snip>

> +void __init at91_ioremap_ramc(int id, u32 addr, u32 size)
> +{
> +	if (id > 1) {
> +		pr_warn("%s: id > 2\n", __func__);
> +		return;
> +	}
> +	at91_ramc_base[id] = ioremap(addr, size);
> +	if (!at91_ramc_base[id])
> +		pr_warn("Impossible to ioremap ramc.%d 0x%x\n", id, addr);
> +}

If this fails then you will oops if you call either at91_ramc_read or
at91_ramc_write since they don't check if at91_ramc_base[id] is a valid
pointer. Either this function should panic, like the other at91_ioremap
functions, or the at91_ramc_read/write functions should check for a
valid pointer.

Nitpick: The id check should probably also be BUG() or WARN() since it
indicates a bug in the core AT91 code. pr_warn is likely to missed and
not reported by users. Since the value is int, the check should be:

  if (id < 0 || id > 1)

Obviously the chance of this error happening are slim, but if you are
going to check and warn for it, it should be done properly :-).

~Ryan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/