linux-kernel - Re: [PATCH resend] s390: oprofile: fix error checks in oprofile_hwsampler

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 for Android: free password hash cracker in your pocket

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

Date:	Tue, 3 May 2011 10:55:40 +0200
From:	Robert Richter <robert.richter@....com>
To:	Nicolas Kaiser <nikai@...ai.net>
CC:	Martin Schwidefsky <schwidefsky@...ibm.com>,
	Heiko Carstens <heiko.carstens@...ibm.com>,
	"linux390@...ibm.com" <linux390@...ibm.com>,
	"oprofile-list@...ts.sf.net" <oprofile-list@...ts.sf.net>,
	"linux-s390@...r.kernel.org" <linux-s390@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH resend] s390: oprofile: fix error checks in
 oprofile_hwsampler_init()

On 02.05.11 09:48:05, Nicolas Kaiser wrote:
> Checking 'oprofile_min_interval < 0' and
> 'oprofile_max_interval < 0' doesn't work because
> 'oprofile_min_interval' and 'oprofile_max_interval' are unsigned.

max/min_interval are through all the code always unsigned. I don't
know how min/max_sampl_rate in struct hws_qsi_info_block is spec'ed,
but there it is unsigned too.

So the best would be to return qsi.min/max_sampl_rate in
hwsampler_query_min/max_interval() directly with no error codes as
unsigned longs and to change the code in oprofile_hwsampler_init() to
check for null. Both functions hwsampler_query_min/max_interval()
could be moved to hwsampler.h as static inline functions. This makes
the code also easier.

This patch does not handle the null value case and the data truncation
by casting from unsigned to singed is not fixed.

-Robert

> 
> Signed-off-by: Nicolas Kaiser <nikai@...ai.net>
> ---
> Untested.
> 
>  arch/s390/oprofile/init.c |   12 ++++++++----
>  1 files changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/s390/oprofile/init.c b/arch/s390/oprofile/init.c
> index c63d7e5..09c3088 100644
> --- a/arch/s390/oprofile/init.c
> +++ b/arch/s390/oprofile/init.c
> @@ -138,22 +138,26 @@ static int oprofile_create_hwsampling_files(struct super_block *sb,
>  
>  static int oprofile_hwsampler_init(struct oprofile_operations *ops)
>  {
> +	long retval;
> +
>  	if (hwsampler_setup())
>  		return -ENODEV;
>  
>  	/*
>  	 * create hwsampler files only if hwsampler_setup() succeeds.
>  	 */
> -	oprofile_min_interval = hwsampler_query_min_interval();
> -	if (oprofile_min_interval < 0) {
> +	retval = hwsampler_query_min_interval();
> +	if (retval < 0) {
>  		oprofile_min_interval = 0;
>  		return -ENODEV;
>  	}
> -	oprofile_max_interval = hwsampler_query_max_interval();
> -	if (oprofile_max_interval < 0) {
> +	oprofile_min_interval = retval;
> +	retval = hwsampler_query_max_interval();
> +	if (retval < 0) {
>  		oprofile_max_interval = 0;
>  		return -ENODEV;
>  	}
> +	oprofile_max_interval = retval;
>  
>  	if (oprofile_timer_init(ops))
>  		return -ENODEV;
> -- 
> 1.7.3.4
> 

-- 
Advanced Micro Devices, Inc.
Operating System Research Center

--
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/