linux-kernel - Re: [PATCH] kmemleak: record accurate early log buffer count and report when exceeded

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] [day] [month] [year] [list]

Date:	Thu, 16 Apr 2015 07:23:03 +0800
From:	Wang Kai <morgan.wang@...wei.com>
To:	Catalin Marinas <catalin.marinas@....com>
CC:	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] kmemleak: record accurate early log buffer count and
 report when exceeded

Thanks a lot for the correction.

On 2015/4/15 23:13, Catalin Marinas wrote:
> (I see you corrected the LKML address; I replied to your early patch)
> 
> On Wed, Apr 15, 2015 at 12:49:23PM +0100, Wang Kai wrote:
>> In log_early function, crt_early_log should also count once when
>> 'crt_early_log >= ARRAY_SIZE(early_log)'. Otherwise the reported
>> count from kmemleak_init is one less than 'actual number'.
>>
>> Then, in kmemleak_init, if early_log buffer size equal actual
>> number, kmemleak will init sucessful, so change warning condition
>> to 'crt_early_log > ARRAY_SIZE(early_log)'.
>>
>> Signed-off-by: Wang Kai <morgan.wang@...wei.com>
>> ---
>>  mm/kmemleak.c |    5 ++++-
>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/mm/kmemleak.c b/mm/kmemleak.c
>> index 5405aff..49956cf 100644
>> --- a/mm/kmemleak.c
>> +++ b/mm/kmemleak.c
>> @@ -814,6 +814,8 @@ static void __init log_early(int op_type, const void *ptr, size_t size,
>>  	}
>>  
>>  	if (crt_early_log >= ARRAY_SIZE(early_log)) {
>> +		/* kmemleak will stop recording, just count the requests */
> 
> You could say "just count the last request" since kmemleak_disable()
> would set kmemleak_error to 1 and you never get to this block again.
> 
>> +		crt_early_log++;
>>  		kmemleak_disable();
>>  		return;
>>  	}
>> @@ -1829,7 +1831,8 @@ void __init kmemleak_init(void)
>>  	object_cache = KMEM_CACHE(kmemleak_object, SLAB_NOLEAKTRACE);
>>  	scan_area_cache = KMEM_CACHE(kmemleak_scan_area, SLAB_NOLEAKTRACE);
>>  
>> -	if (crt_early_log >= ARRAY_SIZE(early_log))
>> +	/* Don't warning when crt_early_log == ARRAY_SIZE(early_log) */
> 
> s/warning/warn/
> 
> But I don't think this comment is needed, just add it to the commit log.
> 
>> +	if (crt_early_log > ARRAY_SIZE(early_log))
>>  		pr_warning("Early log buffer exceeded (%d), please increase "
>>  			   "DEBUG_KMEMLEAK_EARLY_LOG_SIZE\n", crt_early_log);
> 
> Otherwise, my ack still stands:
> 
> Acked-by: Catalin Marinas <catalin.marinas@....com>
> 
> .
> 


--
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/