[Toybox] ls -Z with relative paths

[enh]

yep, see it now. thanks.

On Fri, Jan 15, 2016 at 3:08 PM, Rob Landley <rob at landley.net> wrote:
> Darn it, I was sure I'd committed that already.
>
> The downside of git is I have 3 machines with active trees on them,
> although it's _mostly_ on the netbook...
>
> Try now?
>
> Rob
>
> On 01/15/2016 03:03 PM, enh wrote:
>> ping? (i was hoping to get this into this friday's android toybox
>> update. it's my only internal toybox bug that's > 1wk old at the
>> moment.)
>>
>> On Tue, Jan 12, 2016 at 12:56 PM, enh <enh at google.com> wrote:
>>> On Mon, Jan 11, 2016 at 1:17 PM, Rob Landley <rob at landley.net> wrote:
>>>> On 01/09/2016 03:38 PM, enh wrote:
>>>>> i have the following internal bug:
>>>>>
>>>>> ls -laZ doesn't properly return the SELinux label for files where a
>>>>> non-fully qualified path is provided.
>>>>>
>>>>> Steps to reproduce (on Nexus 9):
>>>>>
>>>>>   adb shell ls -laZ /sys/kernel/debug/tracing/tracing_on
>>>>>   adb shell ls -laZ /sys/kernel/debug/tracing/ | grep tracing_on
>>>>>   adb shell 'cd /sys/kernel/debug/tracing ; ls -laZ tracing_on'
>>>>>
>>>>> Expected: The output of all commands should yield the same SELinux
>>>>> label: "u:object_r:debugfs_tracing:s0"
>>>>
>>>> I have now ordered a 1 gig quad processor raspberry pi "b" to try to
>>>> fling marshmallow upon. (I really need an android test environment, and
>>>> that's powerful enough to potentially self-host, so...)
>>>>
>>>> (I would have ordered a b+ but those are all 512M with 700 mhz processor
>>>> and I think it's only dual core... Not sure how "+" works into it here.)
>>>
>>> (i realize you probably just wanted an excuse to buy a Raspberry Pi,
>>> but the x86 emulator using kvm is very fast, you know.)
>>>
>>>>> something like this seems sensible for ls:
>>>>>
>>>>> diff --git a/toys/posix/ls.c b/toys/posix/ls.c
>>>>> index 2f44d24..08ae695 100644
>>>>> --- a/toys/posix/ls.c
>>>>> +++ b/toys/posix/ls.c
>>>>> @@ -541,6 +541,7 @@ void ls_main(void)
>>>>>    // Iterate through command line arguments, collecting directories and files.
>>>>>    // Non-absolute paths are relative to current directory.
>>>>>    TT.files = dirtree_start(0, 0);
>>>>> +  TT.files->dirfd = AT_FDCWD;
>>>>>    for (s = *toys.optargs ? toys.optargs : noargs; *s; s++) {
>>>>>      dt = dirtree_start(*s, !(toys.optflags&(FLAG_l|FLAG_d|FLAG_F)) ||
>>>>>                              (toys.optflags&(FLAG_L|FLAG_H)));
>>>>
>>>> Yes, that's the correct fix. (I just independently did that before
>>>> noticing the second half of your message. :)
>>>
>>> not sure whether you mean you've already applied a fix but not pushed,
>>> but in case you haven't, patch attached.
>>>
>>>>> but i'm not sure whether the semantics of dirtree_start are supposed
>>>>> to imply this? certainly defaulting dirfd to -1 rather than 0 might
>>>>> lead to fewer surprises in future.
>>>>
>>>> The ls recursion is unusual because ls's recursion semantics are funky.
>>>> (It does two passes over the data to pad out columns, the "label this
>>>> directory or not" logic involves knowledge of other arguments, and so on.)
>>>>
>>>> So to implement what posix wants, ls takes manual control over recursion
>>>> (calling dirtree_recurse() itself in listfiles()), which uses mostly the
>>>> same data structure and mostly the same functions, but just... connects
>>>> them up strangely so it can do crazy things that straddle nodes.
>>>>
>>>> This is why there's a fake node at the top of the ls tree representing
>>>> ".", which is not usually the case. (The manual recursion in ls requires
>>>> a parent node to operate, the common infrastructure doesn't). So our
>>>> "did we fall off the top of the tree logic and have no ->parent,
>>>> therefore AT_CWD" logic doesn't trigger, and sticking AT_CWD into the
>>>> fake top of tree node as its dirfd is the correct response.
>>>>
>>>> Rob
>>>
>>>
>>>
>>> --
>>> Elliott Hughes - http://who/enh - http://jessies.org/~enh/
>>> Android native code/tools questions? Mail me/drop by/add me as a reviewer.
>>
>>
>>



-- 
Elliott Hughes - http://who/enh - http://jessies.org/~enh/
Android native code/tools questions? Mail me/drop by/add me as a reviewer.