Re: [PATCH 1/2] selftests: Remove forced unbuffering for test running

[shuah <shuah@kernel.org>]

On 5/20/19 11:21 PM, Takashi Iwai wrote:
> On Tue, 21 May 2019 00:37:48 +0200,
> Kees Cook wrote:
>>
>> As it turns out, the "stdbuf" command will actually force all
>> subprocesses into unbuffered output, and some implementations of "echo"
>> turn into single-character writes, which utterly wrecks writes to /sys
>> and /proc files.
>>
>> Instead, drop the "stdbuf" usage, and for any tests that want explicit
>> flushing between newlines, they'll have to add "fflush(stdout);" as
>> needed.
>>
>> Reported-by: Takashi Iwai <tiwai@suse.de>
>> Fixes: 5c069b6dedef ("selftests: Move test output to diagnostic lines")
>> Signed-off-by: Kees Cook <keescook@chromium.org>
> 
> Tested-by: Takashi Iwai <tiwai@suse.de>
> 
> BTW, this might be specific to shell invocation.  As in the original
> discussion thread, it starts working when I replace "echo" with
> "/usr/bin/echo".
> 
> Still it's not easy to control in a script itself, so dropping the
> unbuffered mode is certainly safer, yes.
> 
> Thanks!

Thank you both.

I will get this in for next rc.

-- Shuah