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@xxxxxxx> Fixes: 5c069b6dedef ("selftests: Move test output to diagnostic lines") Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>Tested-by: Takashi Iwai <tiwai@xxxxxxx> 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
