-current amd64 sometimes dumps core when creating a FAT32 image.
Minimal reproducer below; other FS types, sizes or files are stable,
FAT32 seems to be the culprit. I don't have time to look into this.
$ cd /usr/src/*bin/makefs
$ make DEBUG=-g
$ mkdir empty/
$ until ! ./obj/makefs -t msdos -o fat_type=32 -s 257M ./empty.img
./empty/ ; do true ; done
[...]
Takes a few seconds/retries at most for me.
Creating `./empty.img'
./empty.img: 525272 sectors in 65659 FAT32 clusters (4096 bytes/cluster)
MBR type: 11
bps=512 spc=8 res=32 nft=2 mid=0xf0 spt=63 hds=255 hid=0 bsec=526336
bspf=513 rdcl=2 infs=1 bkbs=2
Segmentation fault (core dumped)
$ egdb -q ./obj/makefs ./makefs.core -batch -ex bt
[New process 372642]
Core was generated by `makefs'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x000008b6b4acb899 in msdosfs_mount (devvp=0x7be6c6083870,
flags=<optimized out>) at /s/usr.sbin/makefs/msdos/msdosfs_vfsops.c:287
287 && !memcmp(fp->fsisig4, "\0\0\125\252", 4))
#0 0x000008b6b4acb899 in msdosfs_mount (devvp=0x7be6c6083870,
flags=<optimized out>) at /s/usr.sbin/makefs/msdos/msdosfs_vfsops.c:287
#1 0x000008b6b4ac64fb in msdos_makefs (image=0x7be6c6083bcc
"./empty.img", dir=0x7be6c6083bdc "./empty/", root=0x8b927f57660,
fsopts=0x7be6c60838d0) at /s/usr.sbin/makefs/msdos.c:149
#2 0x000008b6b4ab6343 in main (argc=2, argv=<optimized out>) at
/s/usr.sbin/makefs/makefs.c:211
It always chokes on fp->fsisig4.
