On Wed, 1 Feb 2023 at 06:04, Rae Moar <rmoar@xxxxxxxxxx> wrote: > > Fix bug of the extra newline characters in debugfs logs. When a > line is added to debugfs with a newline character at the end, > an extra line appears in the debugfs log. Remove these extra lines. > > Add kunit_log_newline_test to provide test coverage for this issue. > (Also, move kunit_log_test above suite definition to remove the > unnecessary declaration prior to the suite definition) > > Signed-off-by: Rae Moar <rmoar@xxxxxxxxxx> > --- I've got some reservations about this patch. Firstly, could we have an example of the problem in the commit message, so we know what we're fixing? Secondly, I _really_ don't like the way this just removes newlines from log lines if there are too many. It feels like a hack, rather than a proper fix. I suspect the actual issue here is in the kunit_log macro in include/kunit/test.h: https://elixir.bootlin.com/linux/latest/source/include/kunit/test.h#L417 kunit_log_append((test_or_suite)->log, fmt "\n", ##__VA_ARGS__); \ The "\n" concatenated here is probably the issue. The printk statement doesn't add a newline, but that's because printk implicitly does if KERN_CONT is not added. So maybe the correct fix here is to use: printk(KERN_CONT lvl fmt "\n", ##__VA_ARGS__) That'd add the newline, rather than get rid of it, but at least should make the behaviour more similar between printk and the debugfs log. Equally, you could use KERN_CONT and get rid of the "\n" in both places, requiring it in log messages. Thirdly, I don't really like the way the test is skipped if debugfs isn't active. Could we skip it if test->log is not valid instead or using a compile-time #ifdef? I do like the move of kunit_log_test though. That definitely cleans things up! Cheers, -- David > lib/kunit/kunit-test.c | 36 ++++++++++++++++++++++++------------ > lib/kunit/test.c | 9 ++++++++- > 2 files changed, 32 insertions(+), 13 deletions(-) > > diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c > index 4df0335d0d06..e9114a466f1e 100644 > --- a/lib/kunit/kunit-test.c > +++ b/lib/kunit/kunit-test.c > @@ -443,18 +443,6 @@ static struct kunit_suite kunit_resource_test_suite = { > .test_cases = kunit_resource_test_cases, > }; > > -static void kunit_log_test(struct kunit *test); > - > -static struct kunit_case kunit_log_test_cases[] = { > - KUNIT_CASE(kunit_log_test), > - {} > -}; > - > -static struct kunit_suite kunit_log_test_suite = { > - .name = "kunit-log-test", > - .test_cases = kunit_log_test_cases, > -}; > - > static void kunit_log_test(struct kunit *test) > { > struct kunit_suite suite; > @@ -481,6 +469,30 @@ static void kunit_log_test(struct kunit *test) > #endif > } > > +static void kunit_log_newline_test(struct kunit *test) > +{ > +#ifdef CONFIG_KUNIT_DEBUGFS > + kunit_info(test, "extra newline\n"); > + > + KUNIT_ASSERT_NOT_NULL_MSG(test, strstr(test->log, "extra newline\n"), > + "Missing log line, full log:\n%s", test->log); > + KUNIT_EXPECT_NULL(test, strstr(test->log, "extra newline\n\n")); > +#else > + kunit_skip(test, "only useful when debugfs is enabled"); > +#endif > +} > + > +static struct kunit_case kunit_log_test_cases[] = { > + KUNIT_CASE(kunit_log_test), > + KUNIT_CASE(kunit_log_newline_test), > + {} > +}; > + > +static struct kunit_suite kunit_log_test_suite = { > + .name = "kunit-log-test", > + .test_cases = kunit_log_test_cases, > +}; > + > static void kunit_status_set_failure_test(struct kunit *test) > { > struct kunit fake; > diff --git a/lib/kunit/test.c b/lib/kunit/test.c > index 27763f0b420c..76d9c31943bf 100644 > --- a/lib/kunit/test.c > +++ b/lib/kunit/test.c > @@ -117,6 +117,7 @@ void kunit_log_append(char *log, const char *fmt, ...) > char line[KUNIT_LOG_SIZE]; > va_list args; > int len_left; > + int line_len; > > if (!log) > return; > @@ -125,10 +126,16 @@ void kunit_log_append(char *log, const char *fmt, ...) > if (len_left <= 0) > return; > > + // Evaluate the length of the line with arguments > va_start(args, fmt); > - vsnprintf(line, sizeof(line), fmt, args); > + line_len = vsnprintf(line, sizeof(line), fmt, args); > va_end(args); > > + // If line has two newline characters, do not print > + // second newline character > + if (fmt[strlen(fmt) - 2] == '\n') > + line[line_len - 1] = '\0'; > + > strncat(log, line, len_left); > } > EXPORT_SYMBOL_GPL(kunit_log_append); > -- > 2.39.1.456.gfc5497dd1b-goog >
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