Re: [PATCH v2 3/3] kunit: fix bug of extra newline characters in debugfs logs
From: Rae Moar
Date: Thu Feb 23 2023 - 16:45:24 EST
On Thu, Feb 23, 2023 at 12:51 AM David Gow <davidgow@xxxxxxxxxx> wrote:
>
> On Thu, 23 Feb 2023 at 02:27, 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.
> >
> > This is due to a discrepancy between how the lines are printed and how they
> > are added to the logs. Remove this discrepancy by checking if the a newline
>
> Nit: "if the a"?
Thanks for catching this. I will change this to "if a."
>
> > character is present before adding a newline character to the log. This
> > should closely match the printk behavior.
> >
> > 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)
> >
> > As an example, say we add these two lines to the log:
> >
> > kunit_log(..., “KTAP version 1\n”);
> > kunit_log(..., “1..1”);
>
> Nit: Please use regular quotes here ("), rather than the "smart quotes" (“”).
Oops. Thanks. I will change these quotes.
>
> >
> > The debugfs log before this fix:
> >
> > KTAP version 1
> >
> > 1..1
> >
> > The debugfs log after this fix:
> >
> > KTAP version 1
> > 1..1
> >
> > Signed-off-by: Rae Moar <rmoar@xxxxxxxxxx>
> > ---
> >
> This overall seems better. I haven't finished reviewing the series
> yet, but there are a few obvious issues with this patch still...
>
> Most notably, kunit-log-test.kunit_log_test now fails.
>
> -- David
>
> > Changes from v1 -> v2:
> > - Changed the way extra newlines are removed. Instead of removing extra
> > newline characters, add a newline if one is not present. This is a bit
> > cleaner.
> > - Add before and after results to the commit message.
> > - Note: I looked into using KERN_CONT to match the printk behavior to
> > vsnprintf but this could cause issues with KTAP printing on the same line
> > as interrupting kernel messages. I also looked at adding KERN_CONT
> > functionality to kunit_log and I did get this to work but it was a bit
> > messy because it required a few calls to kunit_log_newline in
> > kunit_run_tests. If this is very desired functionality, happy to add this
> > to version 3.
> >
> > include/kunit/test.h | 9 ++++++++-
> > lib/kunit/kunit-test.c | 35 +++++++++++++++++++++++------------
> > lib/kunit/test.c | 14 ++++++++++++++
> > 3 files changed, 45 insertions(+), 13 deletions(-)
> >
> > diff --git a/include/kunit/test.h b/include/kunit/test.h
> > index 0668d29f3453..3031ad29718b 100644
> > --- a/include/kunit/test.h
> > +++ b/include/kunit/test.h
> > @@ -375,6 +375,13 @@ static inline void *kunit_kcalloc(struct kunit *test, size_t n, size_t size, gfp
> >
> > void kunit_cleanup(struct kunit *test);
> >
> > +/**
> > + * kunit_log_newline() - Add newline to the end of log if not already
> > + * present at the end of the log.
> > + * @log: The log to add the newline to.
> > + */
> > +void kunit_log_newline(char *log);
> > +
>
> I don't think this function needs to be public. Maybe keep it static
> and internal to test.c?
Changing this to static makes sense. I will update this.
>
> > void __printf(2, 3) kunit_log_append(char *log, const char *fmt, ...);
> >
> > /**
> > @@ -420,7 +427,7 @@ void __printf(2, 3) kunit_log_append(char *log, const char *fmt, ...);
> > #define kunit_log(lvl, test_or_suite, fmt, ...) \
> > do { \
> > printk(lvl fmt, ##__VA_ARGS__); \
> > - kunit_log_append((test_or_suite)->log, fmt "\n", \
> > + kunit_log_append((test_or_suite)->log, fmt, \
> > ##__VA_ARGS__); \
> > } while (0)
> >
> > diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c
> > index 4df0335d0d06..b63595d3e241 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 +469,29 @@ static void kunit_log_test(struct kunit *test)
> > #endif
> > }
> >
> > +static void kunit_log_newline_test(struct kunit *test)
> > +{
> > + kunit_info(test, "Add newline\n");
> > + if (test->log) {
> > + KUNIT_ASSERT_NOT_NULL_MSG(test, strstr(test->log, "Add newline\n"),
> > + "Missing log line, full log:\n%s", test->log);
> > + KUNIT_EXPECT_NULL(test, strstr(test->log, "Add newline\n\n"));
> > + } else {
> > + kunit_skip(test, "only useful when debugfs is enabled");
> > + }
> > +}
> > +
> > +static struct kunit_case kunit_log_test_cases[] = {
> > + KUNIT_CASE(kunit_log_test),
>
> This test is failing now:
> [13:42:51] =============== kunit-log-test (2 subtests) ================
> [13:42:51] put this in log.
> [13:42:51] this too.
> [13:42:51] add to suite log.
> [13:42:51] along with this.
> [13:42:51] # kunit_log_test: EXPECTATION FAILED at
> lib/kunit/kunit-test.c:459
> [13:42:51] Expected strstr(test->log, "put this in log.") is not
> null, but is
> [13:42:51] # kunit_log_test: EXPECTATION FAILED at
> lib/kunit/kunit-test.c:461
> [13:42:51] Expected strstr(test->log, "this too.") is not null, but is
> [13:42:51] # kunit_log_test: EXPECTATION FAILED at
> lib/kunit/kunit-test.c:463
> [13:42:51] Expected strstr(suite.log, "add to suite log.") is not
> null, but is
> [13:42:51] # kunit_log_test: EXPECTATION FAILED at
> lib/kunit/kunit-test.c:465
> [13:42:51] Expected strstr(suite.log, "along with this.") is not
> null, but is
> [13:42:51] [FAILED] kunit_log_test
> [13:42:51] [PASSED] kunit_log_newline_test
> [13:42:51] # kunit-log-test: pass:1 fail:1 skip:0 total:2
> [13:42:51] # Totals: pass:1 fail:1 skip:0 total:2
> [13:42:51] ================= [FAILED] kunit-log-test ==================
>
Sorry I did not catch this earlier. I must have tested on an outdated
version of my code. The fix here is I am missing a "+ 1" in
kunit_log_append(). This fix is for the first patch in this series and
the specific line change is:
- len = vsnprintf(NULL, 0, fmt, args);
+ len = vsnprintf(NULL, 0, fmt, args) + 1;
I will update this in the next version.
> > + 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 fb6b39cca0ae..1ea981392af3 100644
> > --- a/lib/kunit/test.c
> > +++ b/lib/kunit/test.c
> > @@ -108,6 +108,17 @@ static void kunit_print_test_stats(struct kunit *test,
> > stats.total);
> > }
> >
> > +void kunit_log_newline(char *log)
> > +{
> > + int log_len, len_left;
> > +
> > + log_len = strlen(log);
> > + len_left = KUNIT_LOG_SIZE - log_len - 1;
> > +
> > + if (log_len > 0 && log[log_len - 1] != '\n')
> > + strncat(log, "\n", len_left);
> > +}
> > +
> > /*
> > * Append formatted message to log, size of which is limited to
> > * KUNIT_LOG_SIZE bytes (including null terminating byte).
> > @@ -134,6 +145,9 @@ void kunit_log_append(char *log, const char *fmt, ...)
> > va_start(args, fmt);
> > vsnprintf(log + log_len, min(len, len_left), fmt, args);
> > va_end(args);
> > +
> > + /* Add newline to end of log if not already present. */
> > + kunit_log_newline(log);
> > }
> > EXPORT_SYMBOL_GPL(kunit_log_append);
> >
> > --
> > 2.39.2.637.g21b0678d19-goog
> >