[U-Boot] [PATCH 2/3] test/fs: Check ext4 behaviour if dirent is first entry in directory block

[Brüns, Stefan]

On Dienstag, 13. September 2016 12:33:15 CEST Stephen Warren wrote:
> On 09/12/2016 03:48 PM, Stefan Bruens wrote:
> > On Montag, 12. September 2016 12:39:35 CEST you wrote:
> >> On 09/11/2016 02:46 PM, Stefan Brüns wrote:
> >>> This is a regression test for a crash happening if the first dirent
> >>> in the block matches. Code tried to access a predecessor entry which
> >>> does not exist.
> >>> The crash happened for any block, but "." is always the first entry in
> >>> the first directory block and thus easy to check for.
> >>> 
> >>> diff --git a/test/fs/fs-test.sh b/test/fs/fs-test.sh
> >>> 
> >>> +# Next test case checks writing a file whose dirent
> >>> +# is the first in the block, which is always true for "."
> >>> +# The write should fail, but the lookup should work
> >>> +# Test Case 12 - Check directory traversal
> >>> +${PREFIX}${WRITE} host${SUFFIX} $addr ${FPATH}. 0x10
> >> 
> >> Doesn't that attempt to write a file named ".", which would end up
> >> over-writing the directory content? Unless I'm misunderstanding, that
> >> doesn't seem like a good idea.
> >> 
> >> Also, ${FPATH} might be "", "/", "something", or "something/". Appending
> >> "." to some of those won't work the same way as some others.
> > 
> > "something" can not happen.
> 
> I don't see any code that prevents that. I think it's fairer to say that
> nothing currently happens to call the function with FPATH with a
> trailing /. Someone could easily edit the script later and add such a
> call without knowing about the undocumented restriction.
> 
> I note that in patch 1, the following logic:
> 
> +	if [ ! -z "$6" ]; then
> +		FPATH=${6}/${FPATH}
>   	fi
> 
> ... ends up with FPATH having a leading / for the second invocation of
> test_image by the main script body, since ${6} has the value
> `pwd`/$MOUNT_DIR. That seems to violate FAT's requirement for pathnames
> not to have a leading /.

There are 6 different test runs: { sb, fs, nonfs } x { fat, ext4 }

fs and nonfs can be treated the same way, its just e.g. "ext4ls", "ls" or 
"fatls", "ls" resp. Thats what I called "native" in the other mail.

Now in the "sb" cases, it does not matter if the mounted image is fat or ext4 
- it always uses the full absolute path to the mountpoint.

The specific requirements of ext4 (absolute path) and fat (relative path) only 
apply to the nonfs and fs test runs.

Kind regards,

Stefan