Re: [PATCH] Linux: Work around kernel bugs in chmod on /proc/self/fd paths

[Matheus Castanho <msc at linux dot ibm dot com>]

On 2/13/20 1:54 PM, Adhemerval Zanella wrote:
> 
> 
> On 13/02/2020 13:48, Florian Weimer wrote:
>> * Florian Weimer:
>>
>>> It appears that the ability to change symbolic link modes through such
>>> paths is unintended.  On several file systems, the operation fails with
>>> EOPNOTSUPP, even though the symbolic link permissions are updated.
>>> The expected behavior is a failure to update the permissions, without
>>> file system changes.
>>
>> Adhemerval, you wanted to see this fixed quickly?
> 
> I will try to fully review this today, but skimming it seems fine.
> 

I am seeing the same issue as Adhemerval on powerpc, powerpc64 and
powerpc64le.

I still haven't reviewed the whole patch, but I can at least verify that
it fixes the failing test on ext4 on powerpc (5.4.0-3) and powerpc64le
(4.15.0).

PASS: io/tst-lchmod
original exit status 0
info: testing lchmod
info: testing fchmodat with AT_FDCWD
info: testing fchmodat with relative path
info: re-running tests (after trying to empty /proc)
info: testing lchmod
info: testing fchmodat with AT_FDCWD
info: testing fchmodat with relative path

--
Matheus Castanho