I'm modifying some existing sound code and noticed that when it finishes writing configuration data to the hardware, the code doesn't call snd_pcm_hw_params_free(). The application, for legacy reasons, open and closes the sound hardware for every sound it plays. This has got to be causing memory leak because the snd_pcm_hw_params_t * is never being free'd. So I added a call to `snd_pcm_hw_params_free() and now get the following error:
[root@n00200C709F3D namb2]# ./freetest *** glibc detected *** ./freetest: free(): invalid pointer: 0xbfe39000 *** ======= Backtrace: ========= /lib/libc.so.6[0xb75dc595] /lib/libc.so.6(cfree+0x59)[0xb75dc9d9] /emsnamb/namb2/lib/libasound.so.2(snd_pcm_hw_params_free+0x1d)[0xb7707bad] ./freetest[0x804876b] /lib/libc.so.6(__libc_start_main+0xdc)[0xb7588e9c] ./freetest(memset+0x31)[0x80485b1] ======= Memory map: ======== 08048000-08049000 r-xp 00000000 00:0e 5413865 /var/tmp/namb2/freetest 08049000-0804a000 rwxp 00000000 00:0e 5413865 /var/tmp/namb2/freetest 0804a000-08094000 rwxp 00000000 00:00 0 [heap] b74f1000-b74fc000 r-xp 00000000 fe:00 48544 /lib/libgcc_s-4.1.2-20080825.so.1 b74fc000-b74fd000 rwxp 0000a000 fe:00 48544 /lib/libgcc_s-4.1.2-20080825.so.1 b7506000-b7516000 rwxs 00000000 00:04 149192707 /SYSV0056a4d6 (deleted) b7516000-b7526000 rwxs 00000000 00:0d 1789 /dev/snd/pcmC0D0p b7526000-b7527000 rwxp 00000000 00:00 0 b7527000-b752e000 r-xp 00000000 fe:00 48586 /lib/librt-2.5.so b752e000-b752f000 r-xp 00006000 fe:00 48586 /lib/librt-2.5.so b752f000-b7530000 rwxp 00007000 fe:00 48586 /lib/librt-2.5.so b7530000-b7531000 rwxp 00000000 00:00 0 b7531000-b7544000 r-xp 00000000 fe:00 48582 /lib/libpthread-2.5.so b7544000-b7545000 r-xp 00013000 fe:00 48582 /lib/libpthread-2.5.so b7545000-b7546000 rwxp 00014000 fe:00 48582 /lib/libpthread-2.5.so b7546000-b7548000 rwxp 00000000 00:00 0 b7548000-b754a000 r-xp 00000000 fe:00 48536 /lib/libdl-2.5.so b754a000-b754b000 r-xp 00001000 fe:00 48536 /lib/libdl-2.5.so b754b000-b754c000 rwxp 00002000 fe:00 48536 /lib/libdl-2.5.so b754c000-b7571000 r-xp 00000000 fe:00 48557 /lib/libm-2.5.so b7571000-b7572000 r-xp 00024000 fe:00 48557 /lib/libm-2.5.so b7572000-b7573000 rwxp 00025000 fe:00 48557 /lib/libm-2.5.so b7573000-b76b2000 r-xp 00000000 fe:00 48509 /lib/libc-2.5.so b76b2000-b76b4000 r-xp 0013f000 fe:00 48509 /lib/libc-2.5.so b76b4000-b76b5000 rwxp 00141000 fe:00 48509 /lib/libc-2.5.so b76b5000-b76b8000 rwxp 00000000 00:00 0 b76be000-b76bf000 rwxs 81000000 00:0d 1789 /dev/snd/pcmC0D0p b76bf000-b76c0000 r-xs 80000000 00:0d 1789 /dev/snd/pcmC0D0p b76c0000-b76c1000 rwxs 00000000 00:04 149159938 /SYSV0056a4d5 (deleted) b76c1000-b779b000 r-xp 00000000 fe:00 48500 /lib/libasound.so.2.0.0 b779b000-b77a0000 rwxp 000d9000 fe:00 48500 /lib/libasound.so.2.0.0 b77a0000-b77a1000 rwxp 00000000 00:00 0 b77a1000-b77a2000 r-xp 00000000 00:00 0 [vdso] b77a2000-b77bc000 r-xp 00000000 fe:00 48490 /lib/ld-2.5.so b77bc000-b77bd000 r-xp 00019000 fe:00 48490 /lib/ld-2.5.so b77bd000-b77be000 rwxp 0001a000 fe:00 48490 /lib/ld-2.5.so bfe1a000-bfe3b000 rwxp 00000000 00:00 0 [stack] Aborted A test program below shows this problem. Is this an indication that my installation of libasound is broken in some way?
#include <stdio.h> #include <stdlib.h> #include <errno.h> #include <alsa/asoundlib.h> int main(int argc, char *argv[]) { snd_pcm_t *handle; snd_pcm_hw_params_t *params; int rc; if((rc = snd_pcm_open(&handle, "default", SND_PCM_STREAM_PLAYBACK, 0)) < 0) { printf("Playback open error: %s\n", snd_strerror(rc)); exit(EXIT_FAILURE); } /* Allocate a hardware parameters object. */ snd_pcm_hw_params_alloca(¶ms); /* Fill it in with default values. */ if (snd_pcm_hw_params_any(handle, params) < 0) { fprintf(stderr, "Can not configure this PCM device.\n"); snd_pcm_close(handle); return(-1); } /* Write the parameters to the driver */ if ( (rc = snd_pcm_hw_params(handle, params)) < 0 ) { fprintf(stderr, "unable to set hw parameters: %s\n", snd_strerror(rc)); snd_pcm_close(handle); return -1; } snd_pcm_hw_params_free(params); snd_pcm_close(handle); return 0; }