eal: fix side effect in some pointer arithmetic macros

[ upstream commit 1a7374c ]

RTE_PTR_SUB(ptr, x) and RTE_PTR_ALIGN_FLOOR() worked incorrectly
if "ptr" was an expression:

    uint32_t arr[3];

    RTE_PTR_SUB(arr + 1, sizeof(arr[0]));
    // expected: (uint32_t *)((uintptr_t)(arr + 1) - 4) == arr
    // actual:   (uint32_t *)((uintptr_t) arr + 1  - 4) != arr

    RTE_PTR_ALIGN_FLOOR(arr + 2, sizeof(arr[0]));
    // expected: RTE_ALIGN_FLOOR((uintptr_t)(arr + 2), 4) == &arr[2]
    // actual:   RTE_ALIGN_FLOOR((uintptr_t) arr + 2,  4) == &arr[0]

Fix the macros and extend the relevant unit test.
Convert uses of a custom test failure macro to RTE_TEST_ASSERT*().

Fixes: af75078 ("first public release")

Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Reviewed-by: Morten Brørup <mb@smartsharesystems.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Chengwen Feng <fengchengwen@huawei.com>

app/test/test_common.c

@@ -25,31 +25,53 @@ test_macros(int __rte_unused unused_parm)
 #define SMALLER 0x1000U
 #define BIGGER 0x2000U
 #define PTR_DIFF BIGGER - SMALLER
-#define FAIL_MACRO(x)\
-	{printf(#x "() test failed!\n");\
-	return -1;}
 
 	uintptr_t unused = 0;
 	unsigned int smaller = SMALLER, bigger  = BIGGER;
+	uint32_t arr[3];
 
 	RTE_SET_USED(unused);
 
 	RTE_SWAP(smaller, bigger);
-	if (smaller != BIGGER && bigger != SMALLER)
-		FAIL_MACRO(RTE_SWAP);
-	if ((uintptr_t)RTE_PTR_ADD(SMALLER, PTR_DIFF) != BIGGER)
-		FAIL_MACRO(RTE_PTR_ADD);
-	if ((uintptr_t)RTE_PTR_SUB(BIGGER, PTR_DIFF) != SMALLER)
-		FAIL_MACRO(RTE_PTR_SUB);
-	if (RTE_PTR_DIFF(BIGGER, SMALLER) != PTR_DIFF)
-		FAIL_MACRO(RTE_PTR_DIFF);
-	if (RTE_MAX(SMALLER, BIGGER) != BIGGER)
-		FAIL_MACRO(RTE_MAX);
-	if (RTE_MIN(SMALLER, BIGGER) != SMALLER)
-		FAIL_MACRO(RTE_MIN);
-
-	if (strncmp(RTE_STR(test), "test", sizeof("test")))
-		FAIL_MACRO(RTE_STR);
+	RTE_TEST_ASSERT(smaller == BIGGER && bigger == SMALLER,
+		"RTE_SWAP");
+	RTE_TEST_ASSERT_EQUAL((uintptr_t)RTE_PTR_ADD(SMALLER, PTR_DIFF), BIGGER,
+		"RTE_PTR_ADD");
+	RTE_TEST_ASSERT_EQUAL((uintptr_t)RTE_PTR_SUB(BIGGER, PTR_DIFF), SMALLER,
+		"RTE_PTR_SUB");
+	RTE_TEST_ASSERT_EQUAL(RTE_PTR_DIFF(BIGGER, SMALLER), PTR_DIFF,
+		"RTE_PTR_DIFF");
+	RTE_TEST_ASSERT_EQUAL(RTE_MAX(SMALLER, BIGGER), BIGGER,
+		"RTE_MAX");
+	RTE_TEST_ASSERT_EQUAL(RTE_MIN(SMALLER, BIGGER), SMALLER,
+		"RTE_MIN");
+
+	RTE_TEST_ASSERT_EQUAL(RTE_PTR_ADD(arr + 1, sizeof(arr[0])), &arr[2],
+		"RTE_PTR_ADD(expr, x)");
+	RTE_TEST_ASSERT_EQUAL(RTE_PTR_SUB(arr + 1, sizeof(arr[0])), &arr[0],
+		"RTE_PTR_SUB(expr, x)");
+	RTE_TEST_ASSERT_EQUAL(RTE_PTR_ALIGN_FLOOR(arr + 2, 4), &arr[2],
+		"RTE_PTR_ALIGN_FLOOR(expr, x)");
+	RTE_TEST_ASSERT_EQUAL(RTE_PTR_ALIGN_CEIL(arr + 2, 4), &arr[2],
+		"RTE_PTR_ALIGN_CEIL(expr, x)");
+	RTE_TEST_ASSERT_EQUAL(RTE_PTR_ALIGN(arr + 2, 4), &arr[2],
+		"RTE_PTR_ALIGN(expr, x)");
+
+	RTE_TEST_ASSERT_EQUAL(
+		RTE_PTR_ALIGN_FLOOR(RTE_PTR_ADD(&arr[1], 1), 4), &arr[1],
+		"RTE_PTR_ALIGN_FLOOR(x < y/2, y)");
+	RTE_TEST_ASSERT_EQUAL(
+		RTE_PTR_ALIGN_FLOOR(RTE_PTR_ADD(&arr[1], 3), 4), &arr[1],
+		"RTE_PTR_ALIGN_FLOOR(x > y/2, y)");
+	RTE_TEST_ASSERT_EQUAL(
+		RTE_PTR_ALIGN_CEIL(RTE_PTR_ADD(&arr[1], 3), 4), &arr[2],
+		"RTE_PTR_ALIGN_CEIL(x < y/2, y)");
+	RTE_TEST_ASSERT_EQUAL(
+		RTE_PTR_ALIGN_CEIL(RTE_PTR_ADD(&arr[1], 1), 4), &arr[2],
+		"RTE_PTR_ALIGN_CEIL(x > y/2, y)");
+
+	RTE_TEST_ASSERT(strncmp(RTE_STR(test), "test", sizeof("test")) == 0,
+		"RTE_STR");
 
 	return 0;
 }

lib/eal/include/rte_common.h

@@ -270,7 +270,7 @@ static void __attribute__((destructor(RTE_PRIO(prio)), used)) func(void)
 /**
  * subtract a byte-value offset from a pointer
  */
-#define RTE_PTR_SUB(ptr, x) ((void*)((uintptr_t)ptr - (x)))
+#define RTE_PTR_SUB(ptr, x) ((void *)((uintptr_t)(ptr) - (x)))
 
 /**
  * get the difference between two pointer values, i.e. how far apart
@@ -295,7 +295,7 @@ static void __attribute__((destructor(RTE_PRIO(prio)), used)) func(void)
  * must be a power-of-two value.
  */
 #define RTE_PTR_ALIGN_FLOOR(ptr, align) \
-	((typeof(ptr))RTE_ALIGN_FLOOR((uintptr_t)ptr, align))
+	((typeof(ptr))RTE_ALIGN_FLOOR((uintptr_t)(ptr), align))
 
 /**
  * Macro to align a value to a given power-of-two. The resultant value