On Thu, 26 Jan 2017 17:13:50 +0100, Clemens Ladisch wrote:
Jörg Müller wrote:
I created an .asoundrc with 194 inputs for each card.
pcm_multi.c:1060: snd_pcm_multi_open: Assertion `!slave_map[sidxs[i]][schannels[i]]' failed.
To me, this looks like a bug.
--8<---------------------------------------------------------------->8-- pcm: multi: allocate slave_map dynamically
Using a fixed-size buffer for an arbitrarily-sized list is not a good idea.
Signed-off-by: Clemens Ladisch clemens@ladisch.de
It turned out that we don't need the array at all. I'll apply the following cleanup (and fix) patch. My previous one was buggy.
thanks,
Takashi
-- 8< -- From: Takashi Iwai tiwai@suse.de Subject: [PATCH] pcm: multi: Drop the fixed slave_map[] in snd_pcm_multi_open()
slave_map[] in snd_pcm_multi_open() is a fixed size array and obviously we have no overflow check, and eventually the program gets an error when more than 64 channels are used.
Although we can modify the code to allocate the array dynamically, it turned out that we can drop the whole slave_map[] thingy in this function when looking at the code closely. In the past, it was used to identify the one-to-many mapping. But the check was dropped, and now it's nothing more than a sanity check.
Reported-by: Jörg Müller joerg.mueller7744@gmail.com Signed-off-by: Takashi Iwai tiwai@suse.de --- src/pcm/pcm_multi.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/src/pcm/pcm_multi.c b/src/pcm/pcm_multi.c index c4b1fba32cac..9e4be7122c0f 100644 --- a/src/pcm/pcm_multi.c +++ b/src/pcm/pcm_multi.c @@ -1015,7 +1015,6 @@ int snd_pcm_multi_open(snd_pcm_t **pcmp, const char *name, snd_pcm_multi_t *multi; unsigned int i; snd_pcm_stream_t stream; - char slave_map[64][64] = { { 0 } }; int err;
assert(pcmp); @@ -1059,8 +1058,6 @@ int snd_pcm_multi_open(snd_pcm_t **pcmp, const char *name, bind->slave_channel = schannels[i]; if (sidxs[i] < 0) continue; - assert(!slave_map[sidxs[i]][schannels[i]]); - slave_map[sidxs[i]][schannels[i]] = 1; } multi->channels_count = channels_count;