From mboxrd@z Thu Jan 1 00:00:00 1970 From: Valentin Corfu Subject: Re: Segmentation Fault in snd_pcm_rate_hw_free() Date: Wed, 05 Aug 2015 09:58:16 +0300 Message-ID: <55C1B408.7010501@gmail.com> References: <55C0C75E.8090501@gmail.com> <55C0D402.8030806@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wi0-f175.google.com (mail-wi0-f175.google.com [209.85.212.175]) by alsa0.perex.cz (Postfix) with ESMTP id EBEED265D6A for ; Wed, 5 Aug 2015 08:59:49 +0200 (CEST) Received: by wibcd8 with SMTP id cd8so10053507wib.1 for ; Tue, 04 Aug 2015 23:59:49 -0700 (PDT) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Takashi Iwai Cc: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Hello Takashi, On 04.08.2015 18:15, Takashi Iwai wrote: > On Tue, 04 Aug 2015 17:02:26 +0200, > Valentin Corfu wrote: >> >> >> On 04.08.2015 17:53, Takashi Iwai wrote: >>> On Tue, 04 Aug 2015 16:08:30 +0200, >>> Valentin Corfu wrote: >>>> Hello ALSA developers, >>>> >>>> I observed one segmentation fault in snd_pcm_rate_hw_free() function, >>>> with the following BT: >>>> >>>> (gdb) up >>>> #1 0xb7554cc1 in raise (sig=6) at >>>> ../nptl/sysdeps/unix/sysv/linux/raise.c:64 >>>> 64 return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig); >>>> (gdb) >>>> #2 0xb75580ee in abort () at abort.c:92 >>>> 92 raise (SIGABRT); >>>> (gdb) >>>> #3 0xb758a7dd in __libc_message (do_abort=2, >>>> fmt=0xb766053c "*** glibc detected *** %s: %s: 0x%s ***\n") >>>> at ../sysdeps/unix/sysv/linux/libc_fatal.c:189 >>>> 189 abort (); >>>> (gdb) >>>> #4 0xb7594a71 in malloc_printerr (action=, >>>> str=, ptr=0x969ae98) at malloc.c:6283 >>>> 6283 __libc_message (action & 2, >>>> (gdb) >>>> #5 0xb759636b in _int_free (av=, p=0x969ae90) >>>> at malloc.c:4795 >>>> 4795 malloc_printerr (check_action, errstr, chunk2mem(p)); >>>> (gdb) >>>> #6 0xb75994bd in __libc_free (mem=0x969ae98) at malloc.c:3738 >>>> 3738 _int_free(ar_ptr, p); >>>> (gdb) >>>> #7 0xb76f3a81 in snd_pcm_rate_hw_free (pcm=0x9685d78) at pcm_rate.c:341 >>>> 341 free(rate->pareas[0].addr); >>> Could you check the content of rate->pareas[0] via gdb? >> (gdb) frame 7 >> #7 0xb76f3a81 in snd_pcm_rate_hw_free (pcm=0x9685d78) at pcm_rate.c:341 >> 341 free(rate->pareas[0].addr); >> (gdb) print rate->pareas[0] >> $1 = {addr = 0x969ae98, first = 0, step = 16} >> (gdb) print rate->pareas[0].addr >> $2 = (void *) 0x969ae98 > And accessing to pareas[0].addr is OK? This is a temporary sample > buffer allocated in alsa-lib rate plugin. > Are you referring if the pointer is valid one? How could I check this? >>>> (gdb) >>>> #8 0xb76d045b in snd_pcm_hw_free (pcm=0x9685d78) at pcm.c:858 >>>> 858 err = pcm->ops->hw_free(pcm->op_arg); >>>> (gdb) >>>> #9 0xb76f826e in snd_pcm_plug_hw_free (pcm=0x96856b0) at pcm_plug.c:1046 >>>> 1046 int err = snd_pcm_hw_free(slave); >>>> (gdb) >>>> #10 0xb76d045b in snd_pcm_hw_free (pcm=0x96856b0) at pcm.c:858 >>>> 858 err = pcm->ops->hw_free(pcm->op_arg); >>>> (gdb) >>>> #11 0x080492ad in main () >>>> >>>> >>>> Could you please give me some hints how to solve this issue? >>>> >>>> I can provide you more info or the test application, if needed. >>>> I can see the issue every time, and I also checked with latest version >>>> of alsa-lib but I got the same results. >>> I don't know of such an error, so far. >>> It smells like some memory corruption to me. >>> >>> If a test case is a simple code, tracking the bug would be easy... >> I have paste it here: >> http://pastebin.com/WJDTz6cE > It works fine on my system. How is your PCM setup? Does the same > problem occur for "plughw" PCM, too? Also, no external PCM rate > plugin is involved? In my setup it is involved the alsa jack plugin, so I'm using the pcm jack when the segmentation fault is visible. I can not reproduce the issue when I'm using "default" / "plughw" PCM. For more info I have pasted the dump() & log at run: http://pastebin.com/jyy7pP9e It is involved here PCM rate conversion at 48000, but not external one. > > Takashi Thank you, Valentin