| Message ID | 20190520223749.13476-2-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | e8108866cac5058ae5aff5fa601f91bda29128f2 |
| Headers | show |
| Series | selftests: Remove forced unbuffering for test running | expand |
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! Takashi > --- > tools/testing/selftests/kselftest/runner.sh | 12 +----------- > 1 file changed, 1 insertion(+), 11 deletions(-) > > diff --git a/tools/testing/selftests/kselftest/runner.sh b/tools/testing/selftests/kselftest/runner.sh > index eff3ee303d0d..00c9020bdda8 100644 > --- a/tools/testing/selftests/kselftest/runner.sh > +++ b/tools/testing/selftests/kselftest/runner.sh > @@ -24,16 +24,6 @@ tap_prefix() > fi > } > > -# If stdbuf is unavailable, we must fall back to line-at-a-time piping. > -tap_unbuffer() > -{ > - if ! which stdbuf >/dev/null ; then > - "$@" > - else > - stdbuf -i0 -o0 -e0 "$@" > - fi > -} > - > run_one() > { > DIR="$1" > @@ -54,7 +44,7 @@ run_one() > echo "not ok $test_num $TEST_HDR_MSG" > else > cd `dirname $TEST` > /dev/null > - (((((tap_unbuffer ./$BASENAME_TEST 2>&1; echo $? >&3) | > + (((((./$BASENAME_TEST 2>&1; echo $? >&3) | > tap_prefix >&4) 3>&1) | > (read xs; exit $xs)) 4>>"$logfile" && > echo "ok $test_num $TEST_HDR_MSG") || > -- > 2.17.1 >
On 5/20/19 11:21 PM, Takashi Iwai wrote: > On Tue, 21 May 2019 00:37:48 +0200, > Kees Cook wrote: >> >> As it turns out, the "stdbuf" command will actually force all >> subprocesses into unbuffered output, and some implementations of "echo" >> turn into single-character writes, which utterly wrecks writes to /sys >> and /proc files. >> >> Instead, drop the "stdbuf" usage, and for any tests that want explicit >> flushing between newlines, they'll have to add "fflush(stdout);" as >> needed. >> >> Reported-by: Takashi Iwai <tiwai@suse.de> >> Fixes: 5c069b6dedef ("selftests: Move test output to diagnostic lines") >> Signed-off-by: Kees Cook <keescook@chromium.org> > > Tested-by: Takashi Iwai <tiwai@suse.de> > > BTW, this might be specific to shell invocation. As in the original > discussion thread, it starts working when I replace "echo" with > "/usr/bin/echo". > > Still it's not easy to control in a script itself, so dropping the > unbuffered mode is certainly safer, yes. > > Thanks! Thank you both. I will get this in for next rc. -- Shuah
diff --git a/tools/testing/selftests/kselftest/runner.sh b/tools/testing/selftests/kselftest/runner.sh index eff3ee303d0d..00c9020bdda8 100644 --- a/tools/testing/selftests/kselftest/runner.sh +++ b/tools/testing/selftests/kselftest/runner.sh @@ -24,16 +24,6 @@ tap_prefix() fi } -# If stdbuf is unavailable, we must fall back to line-at-a-time piping. -tap_unbuffer() -{ - if ! which stdbuf >/dev/null ; then - "$@" - else - stdbuf -i0 -o0 -e0 "$@" - fi -} - run_one() { DIR="$1" @@ -54,7 +44,7 @@ run_one() echo "not ok $test_num $TEST_HDR_MSG" else cd `dirname $TEST` > /dev/null - (((((tap_unbuffer ./$BASENAME_TEST 2>&1; echo $? >&3) | + (((((./$BASENAME_TEST 2>&1; echo $? >&3) | tap_prefix >&4) 3>&1) | (read xs; exit $xs)) 4>>"$logfile" && echo "ok $test_num $TEST_HDR_MSG") ||
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> --- tools/testing/selftests/kselftest/runner.sh | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-)