kunit: fix bug of extra newline characters in debugfs logs

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 a newline
character is present before adding a newline character. 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");

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@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
This commit is contained in:
Rae Moar 2023-03-08 20:39:52 +00:00 committed by Shuah Khan
parent f9a301c331
commit 2c6a96dad5
3 changed files with 42 additions and 13 deletions

View file

@ -420,7 +420,7 @@ 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)

View file

@ -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),
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;

View file

@ -108,6 +108,22 @@ static void kunit_print_test_stats(struct kunit *test,
stats.total);
}
/**
* kunit_log_newline() - Add newline to the end of log if one is not
* already present.
* @log: The log to add the newline to.
*/
static 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).
@ -135,6 +151,8 @@ void kunit_log_append(char *log, const char *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);