[LTP] [PATCH v2] lib: suppress early TDEBUG output before context initialization

[Li Wang]

After commit bf9589d5bd ("lib: move test infrastructure states into
a shared context structure"), each test began printing unexpected
TDEBUG messages like:

  tst_test.c:142: TDEBUG: mmap((nil), 4096, PROT_READ | PROT_WRITE(3), 1, 3, 0)
  tst_test.c:199: TDEBUG: mmap((nil), 4096, PROT_READ | PROT_WRITE(3), 1, 3, 0)

This happens because the logic in tst_res_():

  if (ttype == TDEBUG && context && !context->tdebug)

allows TDEBUG messages to be printed even the context is not yet initialized.
During early test setup (such as in SAFE_MMAP), the shared context may
not be initialized yet, causing debug logs to be emitted unintentionally.

This patch refines the suppression logic in tst_res_() by explicitly checking:
  - Whether `context` has been initialized
  - Whether current is the library test process (`lib_pid`)
  - Whether `tdebug` is enabled

This improves test log clarity and avoids misleading noise during test setup.

Follow-up: commit bf9589d5bd ("lib: move test infrastructure states into a shared context structure")
Signed-off-by: Li Wang <liwang@redhat.com>
Reviewed-by: Cyril Hrubis <chrubis@suse.cz>
---
 lib/tst_test.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/lib/tst_test.c b/lib/tst_test.c
index 6fcd40030..495e022f7 100644
--- a/lib/tst_test.c
+++ b/lib/tst_test.c
@@ -476,8 +476,22 @@ void tst_res_(const char *file, const int lineno, int ttype,
 {
 	va_list va;
 
-	if (ttype == TDEBUG && context && !context->tdebug)
-		return;
+	/*
+	 * Suppress TDEBUG output in these cases:
+	 * 1. No context available (e.g., called before IPC initialization)
+	 * 2. Called from the library process, unless explicitly enabled
+	 * 3. Debug output is not enabled (context->tdebug == 0)
+	 */
+	if (ttype == TDEBUG) {
+		if (!context)
+			return;
+
+		if (context->lib_pid == getpid())
+			return;
+
+		if (!context->tdebug)
+			return;
+	}
 
 	va_start(va, fmt);
 	tst_vres_(file, lineno, ttype, fmt, va);
-- 
2.49.0