Re: kern/52195 (segfault in audio_fill_silence())

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

The following reply was made to PR kern/52195; it has been noted by GNATS.

From: Manuel Bouyer <bouyer%antioche.eu.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: nat%netbsd.org@localhost, gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/52195 (segfault in audio_fill_silence())
Date: Wed, 26 Apr 2017 09:13:30 +0200

 On Tue, Apr 25, 2017 at 10:20:01PM +0000, Nathanial Sloss wrote:
 > The following reply was made to PR kern/52195; it has been noted by GNATS.
 > 
 > From: Nathanial Sloss <nat%netbsd.org@localhost>
 > To: gnats-bugs%netbsd.org@localhost
 > Cc: 
 > Subject: Re: kern/52195 (segfault in audio_fill_silence())
 > Date: Wed, 26 Apr 2017 08:15:42 +1000
 > 
 >  Hi,
 >  
 >  What is the offending portion of code in the previos function of the backtrace.
 >  
 >  The audio_mix.part.27+0x61c?
 
 gdb tells me:
 (gdb) l *(audio_mix+0x61c)
 0x8020a6d4 is in audio_mix (/local/armandeche1/can/src/sys/dev/audio_if.h:107).
 102     static __inline uint8_t *
 103     audio_stream_add_inp(audio_stream_t *s, uint8_t *v, int diff)
 104     {
 105             s->used += diff;
 106             v += diff;
 107             if (v >= s->end)
 108                     v -= s->end - s->start;
 109             return v;
 110     }
 
 but this doesn't make much sense. nm shows that audio_mix.part.27 is at
 0x8020a0b8, but 0x8020a0b8+0x61c points to the same place in code.
 
 Maybe this is better:
 (gdb) l *(audio_mix+0x618)
 0x8020a6d0 is in audio_mix (/local/armandeche1/can/src/sys/dev/audio.c:3531).
 3526            } else {
 3527                    vc->sc_sil_start = inp;
 3528                    vc->sc_sil_count = cc;
 3529                    DPRINTFN(5, ("audio_pint_silence: start fill %p %d\n",
 3530                                 inp, cc));
 3531                    audio_fill_silence(&cb->s.param, inp, cc);
 3532            }
 3533    }
 
 
 -- 
 Manuel Bouyer <bouyer%antioche.eu.org@localhost>
      NetBSD: 26 ans d'experience feront toujours la difference
 --