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

Stephen Hemminger stephen at networkplumber.org
Sat Sep 5 00:11:43 CEST 2020


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 at networkplumber.org>
---
 app/test/test_malloc.c              |  5 ++++-
 lib/librte_eal/include/rte_common.h |  7 ++++---
 lib/librte_eal/include/rte_malloc.h | 28 ++++++++++++++++------------
 3 files changed, 24 insertions(+), 16 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 6b85374c0fe5..0c2e03234d8d 100644
--- a/lib/librte_eal/include/rte_common.h
+++ b/lib/librte_eal/include/rte_common.h
@@ -117,10 +117,11 @@ typedef uint16_t unaligned_uint16_t;
  * cannot alias any other valid pointer and that the memory
  * contents are undefined. I.e behaves like malloc.
  */
-#if RTE_CC_IS_GNU
-#define __rte_malloc __attribute__((malloc))
+#if defined(RTE_CC_GCC) || defined(RTE_CC_CLANG)
+#define __rte_alloc_size(...) \
+	__attribute__((alloc_size(__VA_ARGS__)))
 #else
-#define __rte_malloc
+#define __rte_alloc_size(...)
 #endif
 
 /**
diff --git a/lib/librte_eal/include/rte_malloc.h b/lib/librte_eal/include/rte_malloc.h
index 721560122c70..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.
@@ -79,9 +80,9 @@ rte_malloc(const char *type, size_t size, unsigned align);
  *     align is not a power of two).
  *   - Otherwise, the pointer to the allocated object.
  */
-__rte_malloc
 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
@@ -106,9 +107,9 @@ rte_zmalloc(const char *type, size_t size, unsigned align);
  *     align is not a power of two).
  *   - Otherwise, the pointer to the allocated object.
  */
-__rte_malloc
 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
@@ -131,7 +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
@@ -157,7 +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
@@ -182,9 +185,9 @@ rte_realloc_socket(void *ptr, size_t size, unsigned int align, int socket);
  *     align is not a power of two).
  *   - Otherwise, the pointer to the allocated object.
  */
-__rte_malloc
 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.
@@ -212,7 +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
@@ -239,9 +243,9 @@ rte_zmalloc_socket(const char *type, size_t size, unsigned align, int socket);
  *     align is not a power of two).
  *   - Otherwise, the pointer to the allocated object.
  */
-__rte_malloc
 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



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