I was trying to use xcdroast and it kept failing during the reading of data from the CD.  Using "xcdroast -d 1" I saw the xcdroast runs the command cdda2wav like this:

x1-6-00-50-2c-02-55-54:~/cdda2wav#cdda2wav -D "1,0,0" -g -O wav -S 40 -v all -P 
0 -n 75 -paranoia -paraopts=retries=20 -B "track-01.wav" "track-02.wav" "track-0
3.wav" "track-04.wav" "track-05.wav" "track-06.wav" "track-07.wav" "track-08.wav
" "track-09.wav" "track-10.wav" "track-11.wav" "track-12.wav" "track-13.wav" "tr
ack-14.wav"
Type: ROM, Vendor 'LITE-ON ' Model 'LTR-24102B      ' Revision '5S07' MMC+CDDA
266240 bytes buffer memory requested, 4 buffers, 27 sectors
#Cdda2wav version 2.00.3_freebsd_5.1-release-p13_i386_i386, real time sched., so
undcard, libparanoia support
Tracks:14 46:28.32
CDINDEX discid: W2_EXuJmN5nw13xvsoU.aExv_Xg-
CDDB discid: 0xb50ae20e
CD-Text: not detected
CD-Extra: not detected
Album title: '' from ''
T01:       0  3:08.65 audio linear copydenied stereo title '' from ''
T02:   14165  2:55.55 audio linear copydenied stereo title '' from ''
T03:   27345  2:34.05 audio linear copydenied stereo title '' from ''
T04:   38900  2:50.65 audio linear copydenied stereo title '' from ''
T05:   51715  3:30.37 audio linear copydenied stereo title '' from ''
T06:   67502  3:11.38 audio linear copydenied stereo title '' from ''
T07:   81865  2:55.17 audio linear copydenied stereo title '' from ''
T08:   95007  3:19.20 audio linear copydenied stereo title '' from ''
T09:  109952  3:56.65 audio linear copydenied stereo title '' from ''
T10:  127717  3:03.40 audio linear copydenied stereo title '' from ''
T11:  141482  3:57.08 audio linear copydenied stereo title '' from ''
T12:  159265  3:51.25 audio linear copydenied stereo title '' from ''
T13:  176615  2:33.25 audio linear copydenied stereo title '' from ''
T14:  188115  4:38.17 audio linear copydenied stereo title '' from ''
Leadout:  208982
No media catalog number present.
scanning for ISRCs: 14 ...
index scan: 14...samplefile size will be 491525708 bytes.
recording 2786.4266 seconds stereo with 16 bits @ 44100.0 Hz ->'track-01'...
using lib paranoia for reading.
child pid is 51260
percent_done:
  0%cdda2wav: Argument list too long. Cannot send SCSI cmd via ioctl

W Child exited with 2

I have an ATA CD drive and I'm using atapicam to emulate having a SCSI CD drive, because xcdroast doesn't support ATAPI CD drives.

I've never hacked around with this stuff, but here's my best guess as to what's going wrong:

cdda2wav is generating a ccb to send to the CAM XPT module.  ATAPICAM needs to map the userland data into kernel land for the transfer.  To make sure that it fits within a page boundary, there is a check made in sys/cam/cam_periph.c:

                if ((lengths[i] +
                    (((vm_offset_t)(*data_ptrs[i])) & PAGE_MASK)) > DFLTPHYS){
                        printf("cam_periph_mapmem: attempt to map %lu bytes, "
                               "which is greater than DFLTPHYS(%d)\n",
                               (long)(lengths[i] +
                               (((vm_offset_t)(*data_ptrs[i])) & PAGE_MASK)),
                               DFLTPHYS);

cdda2wav isn't aligning the data_ptr properly each time, so the check fails sometimes.

Fix: 

Have cdda2wav send properly aligned addresses, or shink the transfer size down so that the data fits within a page.  I'm not sure how difficult this will be.
How-To-Repeat: 	Need a system with an ATA CD drive, using cdda2wav and atapicam.  Run this command as root:

cdda2wav -V -D "1,0,0" -g -O wav -S 40 -v toc,summary,sectors,titles -P 0 -n 75 -paranoia -paraopts=retries=20 -B "track-01.wav" "track-02.wav" "track-03.wav" "track-04.wav" "track-05.wav" "track-06.wav" "track-07.wav" "track-08.wav" "track-09.wav" "track-10.wav" "track-11.wav" "track-12.wav" "track-13.wav" "track-14.wav"

In my tests, the first ccb always has an aligned pointer, but the second one isn't.