While working on a hobby OS i remarked that my grub is segfaulting when I try to generate HD-Images. After some debugging I found that the patch 810_all_grub-0.97-ext3_256byte_inode.patch in grub-0.97-patches-1.7.tar.bz2 causes this. The problem is in those two lines: 66 +#define EXT2_INODE_SIZE(s) (SUPERBLOCK->s_inode_size) 67 +#define EXT2_INODES_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s)/EXT2_INODE_SIZE(s)) This is because the field s_inode_size is only valid if s_rev_level is EXT2_DYNAMIC_REV (1). So on it may happen, that the value is zero and EXT2_INODES_PER_BLOCK will cause a division by zero. I would suggest to change the INODE_SIZE macro to: #define EXT2_INODE_SIZE(s) (SUPERBLOCK->s_rev_level == 1 ? SUPERBLOCK->s_inode_size : 128) Reproducible: Always Steps to Reproduce: 1. Create some hd image: dd if=/dev/zero of=hd.img bs=1024 count=10240 2. Create a primary partition on the image (you cannot install grub on a non partitioned image): /sbin/fdisk hd.img (you have to go to the expertsmenu[x] and then set the cylinder count[c] to 325) 3. Format the image with ext2-REV0. There are two possibilities, either you use kpartx or you use some dd-magic. I'll show the 2nd possibility: dd if=hd.img of=part bs=512 skip=63; /sbin/mkfs.ext2 -r0 part -F; dd if=part of=hd.img bs=512 seek=63 4. Now mount the partition and copy grub on it: mount -o loop,offset=$((63*512)) hd.img /tmp; cp /path/to/stage/1/and/2 /tmp; umount /tmp 5. Install grub on the image: /sbin/grub; grub> device (hd0) hd.img grub> root (hd0,0) grub> setup (hd0) Actual Results: Segfault Expected Results: There should have been no segfault ;-)
Hum, with the newest e2fsprogs-Version this problem cannot be reproduced, because the inode-size will be set, even if you specify -r0. I used e2fsprogs-1.40.9 to reproduce this bug.
Please test 0.97-r8 that is in package.mask very carefully (aka have a livecd handy), but this should now be fixed.
