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Date: Fri, 7 Jun 2024 10:58:13 +0200
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Subject: Re: [PATCH v3 1/3] slab: make check_object() more consistent
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To: Chengming Zhou <chengming.zhou@linux.dev>,
 Christoph Lameter <cl@linux.com>, Pekka Enberg <penberg@kernel.org>,
 David Rientjes <rientjes@google.com>, Joonsoo Kim <iamjoonsoo.kim@lge.com>,
 Andrew Morton <akpm@linux-foundation.org>,
 Roman Gushchin <roman.gushchin@linux.dev>,
 Hyeonggon Yoo <42.hyeyoo@gmail.com>, Feng Tang <feng.tang@intel.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
 zhouchengming@bytedance.com
References: <20240607-b4-slab-debug-v3-0-bb2a326c4ceb@linux.dev>
 <20240607-b4-slab-debug-v3-1-bb2a326c4ceb@linux.dev>
From: Vlastimil Babka <vbabka@suse.cz>
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In-Reply-To: <20240607-b4-slab-debug-v3-1-bb2a326c4ceb@linux.dev>
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On 6/7/24 10:40 AM, Chengming Zhou wrote:
> Now check_object() calls check_bytes_and_report() multiple times to
> check every section of the object it cares about, like left and right
> redzones, object poison, paddings poison and freepointer. It will
> abort the checking process and return 0 once it finds an error.
> 
> There are two inconsistencies in check_object(), which are alignment
> padding checking and object padding checking. We only print the error
> messages but don't return 0 to tell callers that something is wrong
> and needs to be handled. Please see alloc_debug_processing() and
> free_debug_processing() for details.
> 
> We want to do all checks without skipping, so use a local variable
> "ret" to save each check result and change check_bytes_and_report() to
> only report specific error findings. Then at end of check_object(),
> print the trailer once if any found an error.
> 
> Suggested-by: Vlastimil Babka <vbabka@suse.cz>
> Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>

Reviewed-by: Vlastimil Babka <vbabka@suse.cz>

Thanks.