[LTP] [PATCH v9 1/2] lib: Extend tst_assert_ulong() with enum flags

[Wei Gao]

Introduce enum tst_assert_flags (including TST_ASSERT_NONE,
TST_ASSERT_SATURATED_INT, and TST_ASSERT_TRUNC_32BIT) to
tst_assert_ulong(). This enables type-safe handling of 32-bit
compat-mode truncation and clamping behaviors on 64-bit kernels
when verifying sysfs/procfs limits.

Signed-off-by: Wei Gao <wegao@suse.com>
---
 include/tst_assert.h | 36 +++++++++++++++++++++++++++++++-----
 lib/tst_assert.c     | 26 ++++++++++++++++++++------
 2 files changed, 51 insertions(+), 11 deletions(-)

diff --git a/include/tst_assert.h b/include/tst_assert.h
index dcb62dfea..9154b7249 100644
--- a/include/tst_assert.h
+++ b/include/tst_assert.h
@@ -21,14 +21,40 @@ void tst_assert_int(const char *file, const int lineno,
 #define TST_ASSERT_FILE_INT(path, prefix, val) \
 	tst_assert_file_int(__FILE__, __LINE__, path, prefix, val)
 
-/*
- * Same as tst_assert_int() but for unsigned long.
+/**
+ * enum tst_assert_flags - Flags for tst_assert_ulong().
+ *
+ * @TST_ASSERT_NONE: No flags, default direct comparison.
+ * @TST_ASSERT_SATURATED_INT: Clamps the value at %INT_MAX if it exceeds it.
+ * @TST_ASSERT_TRUNC_32BIT: Keeps only the low 32 bits of the read value,
+ *                          truncating any higher bits.
+ */
+enum tst_assert_flags {
+	TST_ASSERT_NONE          = 0x00,
+	TST_ASSERT_SATURATED_INT = 0x01,
+	TST_ASSERT_TRUNC_32BIT   = 0x02,
+};
+
+/**
+ * tst_assert_ulong() - Assert that an unsigned long value in a file matches.
+ * @file: The source file of the assertion (usually __FILE__).
+ * @lineno: The source line number of the assertion (usually __LINE__).
+ * @path: Path to the sysfs or procfs file to read from.
+ * @val: The expected unsigned long value to compare against.
+ * @flags: Bitwise flags controlling how the read value is processed.
+ *         See &enum tst_assert_flags.
+ *
+ * This function reads an integer value from the file specified by @path
+ * and compares it with @val. It allows handling of 32-bit compat mode
+ * truncation/clamping on 64-bit systems via @flags.
  */
 void tst_assert_ulong(const char *file, const int lineno,
-                      const char *path, unsigned long val);
+                      const char *path, unsigned long val,
+                      enum tst_assert_flags flags);
 
-#define TST_ASSERT_ULONG(path, val) \
-	tst_assert_ulong(__FILE__, __LINE__, path, val)
+#define TST_ASSERT_ULONG(path, val, ...) \
+	tst_assert_ulong(__FILE__, __LINE__, path, val, \
+		TST_2_(dummy, ##__VA_ARGS__, TST_ASSERT_NONE))
 
 /*
  * Asserts that integer value stored in the prefix field of file pointed by path
diff --git a/lib/tst_assert.c b/lib/tst_assert.c
index b68bd5d39..04241d31b 100644
--- a/lib/tst_assert.c
+++ b/lib/tst_assert.c
@@ -23,18 +23,32 @@ void tst_assert_int(const char *file, const int lineno, const char *path, int va
 	tst_res_(file, lineno, TFAIL, "%s != %d got %d", path, val, sys_val);
 }
 
-void tst_assert_ulong(const char *file, const int lineno, const char *path, unsigned long val)
+void tst_assert_ulong(const char *file, const int lineno, const char *path,
+		      unsigned long val, enum tst_assert_flags flags)
 {
-	unsigned long sys_val;
-
-	safe_file_scanf(file, lineno, NULL, path, "%lu", &sys_val);
+	unsigned long long sys_val_64;
+	unsigned long expected_val;
+
+	safe_file_scanf(file, lineno, NULL, path, "%llu", &sys_val_64);
+
+	if (flags & TST_ASSERT_SATURATED_INT) {
+		if (sys_val_64 > (unsigned long long)INT_MAX)
+			expected_val = (unsigned long)INT_MAX;
+		else
+			expected_val = (unsigned long)sys_val_64;
+	} else if (flags & TST_ASSERT_TRUNC_32BIT) {
+		expected_val = (unsigned long)(sys_val_64 & 0xFFFFFFFFULL);
+	} else {
+		expected_val = (unsigned long)sys_val_64;
+	}
 
-	if (val == sys_val) {
+	if (val == expected_val) {
 		tst_res_(file, lineno, TPASS, "%s = %lu", path, val);
 		return;
 	}
 
-	tst_res_(file, lineno, TFAIL, "%s != %lu got %lu", path, val, sys_val);
+	tst_res_(file, lineno, TFAIL, "%s != %lu got %lu (raw: %llu)",
+		path, val, expected_val, sys_val_64);
 }
 
 void tst_assert_file_int(const char *file, const int lineno, const char *path, const char *prefix, int val)
-- 
2.55.0