[dpdk-dev] [PATCH v2] eal/rte_malloc: add alloc_size() attribute to allocation functions

[Stephen Hemminger <stephen@networkplumber.org>]

By using the alloc_size() attribute the compiler can optimize
better and detect errors at compile time.

For example, Gcc will fail one of the invalid allocation examples
in app/test/test_malloc.c because the allocation is outside the
limits of memory.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
v2 - rebase onto correct branch (main)

 app/test/test_malloc.c              |  5 ++++-
 lib/librte_eal/include/rte_common.h | 12 ++++++++++++
 lib/librte_eal/include/rte_malloc.h | 24 ++++++++++++++++--------
 3 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/app/test/test_malloc.c b/app/test/test_malloc.c
index 71b3cfdde5cf..fdf77b4f6a14 100644
--- a/app/test/test_malloc.c
+++ b/app/test/test_malloc.c
@@ -846,6 +846,9 @@ test_malloc_bad_params(void)
 	if (bad_ptr != NULL)
 		goto err_return;
 
+#if defined(RTE_CC_GCC) || defined(RTE_CC_CLANG)
+	/* this test can not be built, will get trapped at compile time! */
+#else
 	/* rte_malloc expected to return null with size will cause overflow */
 	align = RTE_CACHE_LINE_SIZE;
 	size = (size_t)-8;
@@ -857,7 +860,7 @@ test_malloc_bad_params(void)
 	bad_ptr = rte_realloc(NULL, size, align);
 	if (bad_ptr != NULL)
 		goto err_return;
-
+#endif
 	return 0;
 
 err_return:
diff --git a/lib/librte_eal/include/rte_common.h b/lib/librte_eal/include/rte_common.h
index 2920255fc1e3..e63ef0f1de5e 100644
--- a/lib/librte_eal/include/rte_common.h
+++ b/lib/librte_eal/include/rte_common.h
@@ -134,6 +134,18 @@ typedef uint16_t unaligned_uint16_t;
 	__attribute__((format(printf, format_index, first_arg)))
 #endif
 
+/**
+ * Tells compiler that the function returns a value that points to
+ * memory, where the size is given by the one or two arguments.
+ * Used by compiler to validate object size.
+ */
+#if defined(RTE_CC_GCC) || defined(RTE_CC_CLANG)
+#define __rte_alloc_size(...) \
+	__attribute__((alloc_size(__VA_ARGS__)))
+#else
+#define __rte_alloc_size(...)
+#endif
+
 #define RTE_PRIORITY_LOG 101
 #define RTE_PRIORITY_BUS 110
 #define RTE_PRIORITY_CLASS 120
diff --git a/lib/librte_eal/include/rte_malloc.h b/lib/librte_eal/include/rte_malloc.h
index 42ca05182f8e..3af64f87618e 100644
--- a/lib/librte_eal/include/rte_malloc.h
+++ b/lib/librte_eal/include/rte_malloc.h
@@ -54,7 +54,8 @@ struct rte_malloc_socket_stats {
  *   - Otherwise, the pointer to the allocated object.
  */
 void *
-rte_malloc(const char *type, size_t size, unsigned align);
+rte_malloc(const char *type, size_t size, unsigned align)
+	__rte_alloc_size(2);
 
 /**
  * Allocate zero'ed memory from the heap.
@@ -80,7 +81,8 @@ rte_malloc(const char *type, size_t size, unsigned align);
  *   - Otherwise, the pointer to the allocated object.
  */
 void *
-rte_zmalloc(const char *type, size_t size, unsigned align);
+rte_zmalloc(const char *type, size_t size, unsigned align)
+	__rte_alloc_size(2);
 
 /**
  * Replacement function for calloc(), using huge-page memory. Memory area is
@@ -106,7 +108,8 @@ rte_zmalloc(const char *type, size_t size, unsigned align);
  *   - Otherwise, the pointer to the allocated object.
  */
 void *
-rte_calloc(const char *type, size_t num, size_t size, unsigned align);
+rte_calloc(const char *type, size_t num, size_t size, unsigned align)
+	__rte_alloc_size(2, 3);
 
 /**
  * Replacement function for realloc(), using huge-page memory. Reserved area
@@ -129,7 +132,8 @@ rte_calloc(const char *type, size_t num, size_t size, unsigned align);
  *   - Otherwise, the pointer to the reallocated memory.
  */
 void *
-rte_realloc(void *ptr, size_t size, unsigned int align);
+rte_realloc(void *ptr, size_t size, unsigned int align)
+	__rte_alloc_size(2);
 
 /**
  * Replacement function for realloc(), using huge-page memory. Reserved area
@@ -155,7 +159,8 @@ rte_realloc(void *ptr, size_t size, unsigned int align);
  */
 __rte_experimental
 void *
-rte_realloc_socket(void *ptr, size_t size, unsigned int align, int socket);
+rte_realloc_socket(void *ptr, size_t size, unsigned int align, int socket)
+	__rte_alloc_size(2, 3);
 
 /**
  * This function allocates memory from the huge-page area of memory. The memory
@@ -181,7 +186,8 @@ rte_realloc_socket(void *ptr, size_t size, unsigned int align, int socket);
  *   - Otherwise, the pointer to the allocated object.
  */
 void *
-rte_malloc_socket(const char *type, size_t size, unsigned align, int socket);
+rte_malloc_socket(const char *type, size_t size, unsigned align, int socket)
+	__rte_alloc_size(2);
 
 /**
  * Allocate zero'ed memory from the heap.
@@ -209,7 +215,8 @@ rte_malloc_socket(const char *type, size_t size, unsigned align, int socket);
  *   - Otherwise, the pointer to the allocated object.
  */
 void *
-rte_zmalloc_socket(const char *type, size_t size, unsigned align, int socket);
+rte_zmalloc_socket(const char *type, size_t size, unsigned align, int socket)
+	__rte_alloc_size(2);
 
 /**
  * Replacement function for calloc(), using huge-page memory. Memory area is
@@ -237,7 +244,8 @@ rte_zmalloc_socket(const char *type, size_t size, unsigned align, int socket);
  *   - Otherwise, the pointer to the allocated object.
  */
 void *
-rte_calloc_socket(const char *type, size_t num, size_t size, unsigned align, int socket);
+rte_calloc_socket(const char *type, size_t num, size_t size, unsigned align, int socket)
+	__rte_alloc_size(2, 3);
 
 /**
  * Frees the memory space pointed to by the provided pointer.
-- 
2.27.0