Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH v2] perf session: fix decompression of
 PERF_RECORD_COMPRESSED records
To:     Jiri Olsa <jolsa@redhat.com>
Cc:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Andi Kleen <ak@linux.intel.com>,
        linux-kernel <linux-kernel@vger.kernel.org>
References: <ed01646b-3b28-0ce7-04da-4665b8ed8a04@linux.intel.com>
 <20191118122214.GB14046@krava>
From:   Alexey Budankov <alexey.budankov@linux.intel.com>
Organization: Intel Corp.
Message-ID: <924f076a-190f-330f-50e0-f06f35e2ee75@linux.intel.com>
Date:   Mon, 18 Nov 2019 17:20:31 +0300
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101
 Thunderbird/60.9.1
MIME-Version: 1.0
In-Reply-To: <20191118122214.GB14046@krava>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 18.11.2019 15:22, Jiri Olsa wrote:
> On Mon, Nov 18, 2019 at 02:30:04PM +0300, Alexey Budankov wrote:
<SNIP>
>>
>> @@ -1971,20 +1971,32 @@ fetch_mmaped_event(struct perf_session *session,
>>  		return NULL;
>>  
>>  	event = (union perf_event *)(buf + head);
>> +	if (needs_swap)
>> +		perf_event_header__bswap(&event->header);
>>  
>> -	if (session->header.needs_swap)
>> +	if (head + event->header.size <= mmap_size)
>> +		return event;
>> +
>> +	/* We're not fetching the event so swap back again */
>> +	if (needs_swap)
>>  		perf_event_header__bswap(&event->header);
>>  
>> -	if (head + event->header.size > mmap_size) {
>> -		/* We're not fetching the event so swap back again */
>> -		if (session->header.needs_swap)
>> -			perf_event_header__bswap(&event->header);
>> -		pr_debug("%s: head=%#" PRIx64 " event->header_size=%#x, mmap_size=%#zx: fuzzed perf.data?\n",
>> -			 __func__, head, event->header.size, mmap_size);
>> -		return ERR_PTR(-EINVAL);
>> -	}
>> +	pr_debug("%s: head=%#" PRIx64 " event->header_size=%#x, mmap_size=%#zx\n",
>> +		__func__, head, event->header.size, mmap_size);
> 
> you're missign the 'fuzzed perf.data?' in here
> 
> I think we should keep it just change to: 'fuzzed or compressed perf.data?'

Fixed in v3.

> 
> thanks,
> jirka

~Alexey