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@xxxxxxxxxx>
---
Changes from v2 -> v3:
- Changes to commit message.
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.
- 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 just 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 | 2 +-
lib/kunit/kunit-test.c | 35 +++++++++++++++++++++++------------
lib/kunit/test.c | 18 ++++++++++++++++++
3 files changed, 42 insertions(+), 13 deletions(-)
diff --git a/include/kunit/test.h b/include/kunit/test.h
index 0668d29f3453..bd9dbae5e48d 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -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)
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),
+ 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 811fcc376d2f..e2910b261112 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -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);
--
2.40.0.rc0.216.gc4246ad0f0-goog
