Hi,
I have built e2fsprogs-1.42.8 for a MIPS64-based board. The tools were
generated on an Intel machine with a MIPS64 cross compiler.
MIPS64 board info:
Linux kernel: 3.4.27
Cavium Octeon Plus MIPS64 dual core processor
256 MB RAM
The MIPS-based board will have a 2 TB NTFS (or VFAT) formatted
external USB hard drive connected to it. The goal is to format the 2
TB drive from NTFS/ VFAT to EXT4 using the 'mke2fs' program.
'Mke2fs' results in a segmentation fault when formatting to ext4:
mke2fs -t ext4 /dev/sda1
mke2fs 1.42.8 (20-Jun-2013)
Segmentation fault
As a parallel test, I tried formatting to EXT3 and this worked
correctly. The issue only seems to occur for EXT4.
Upon further debug, I found the segmentation fault to occur in
mke2fs.c: end of the should_do_undo() function in the following call:
io_channel_close(channel);
I tried tracing through the code in the should_do_undo() function.
The manager->open() call succeeds.
An issue of note occurs in the following line:
retval = io_channel_read_blk64(channel, 1, -SUPERBLOCK_SIZE, &super);
The following shows the contents of the 'channel' data structure
before and after the above function call:
Before call to io_channel_read_blk64()
-----------------------------------------------------
should_do_undo: Channel structure address = 0x1005fd70
should_do_undo: magic = 2133571333, name: /dev/sda1, block_size = 1024
should_do_undo: refcount = 1, flags = 4, align = 0
After call to io_channel_read_blk64()
---------------------------------------------------
After Read blk64: Channel structure address = 0x668b1e1a
Segmentation fault
So, the io_channel_read_blk64() function somehow modifies the
"channel" structure pointer. Trying to read the structure after the
call results in a seg fault.
In the io_channel_read_blk64() function, the code takes the following route:
if (channel->manager->read_blk64)
return (channel->manager->read_blk64)(channel, block,
count, data);
If you have any thoughts on this issue or need additional details,
please let me know.
Thanks,
Sri
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