[dpdk-dev] [PATCH v12 2/4] DPDK code adapts to ASan

[zhihongx.peng@intel.com]

From: Zhihong Peng <zhihongx.peng@intel.com>

DPDK ASan functionality is currently only supported Linux x86_64.
Support other platforms, need to define ASAN_SHADOW_OFFSET value
according to google ASan document, and configure meson
(config/meson.build).

Here is an example of heap-buffer-overflow bug:
        ......
        char *p = rte_zmalloc(NULL, 7, 0);
        p[7] = 'a';
        ......

Here is an example of use-after-free bug:
        ......
        char *p = rte_zmalloc(NULL, 7, 0);
        rte_free(p);
        *p = 'a';
        ......

Signed-off-by: Xueqin Lin <xueqin.lin@intel.com>
Signed-off-by: Zhihong Peng <zhihongx.peng@intel.com>
---
v7: Split doc and code into two.
v8: No change.
v9: Modify the definition of RTE_MALLOC_ASAN.
v10:Modify the definition of RTE_MALLOC_ASAN.
v11:No change.
v12:No change.
---
 config/meson.build             |   4 +
 doc/guides/prog_guide/asan.rst |  68 +++++++++++-
 lib/eal/common/malloc_elem.c   |  26 ++++-
 lib/eal/common/malloc_elem.h   | 194 ++++++++++++++++++++++++++++++++-
 lib/eal/common/malloc_heap.c   |  12 ++
 lib/eal/common/rte_malloc.c    |   9 +-
 6 files changed, 306 insertions(+), 7 deletions(-)

diff --git a/config/meson.build b/config/meson.build
index f02b0e9c6d..bf751583bd 100644
--- a/config/meson.build
+++ b/config/meson.build
@@ -425,6 +425,10 @@ if get_option('b_sanitize') == 'address' or get_option('b_sanitize') == 'address
         add_project_link_arguments('-lasan', language: 'c')
         dpdk_extra_ldflags += '-lasan'
     endif
+
+    if is_linux and arch_subdir == 'x86'
+	dpdk_conf.set10('RTE_MALLOC_ASAN', true)
+    endif
 endif
 
 if get_option('default_library') == 'both'
diff --git a/doc/guides/prog_guide/asan.rst b/doc/guides/prog_guide/asan.rst
index 969676ebe8..0cb2ca8751 100644
--- a/doc/guides/prog_guide/asan.rst
+++ b/doc/guides/prog_guide/asan.rst
@@ -13,6 +13,68 @@ printing out detailed debug information whenever an error is detected.
 
 AddressSanitizer is a part of LLVM (3.1+) and GCC (4.8+).
 
+DPDK ASan functionality is currently only supported Linux x86_64.
+Support other platforms, need to define ASAN_SHADOW_OFFSET value
+according to google ASan document, and configure meson
+(config/meson.build).
+
+Example heap-buffer-overflow error
+----------------------------------
+
+Following error was reported when ASan was enabled::
+
+    Applied 9 bytes of memory, but accessed the 10th byte of memory,
+    so heap-buffer-overflow appeared.
+
+Below code results in this error::
+
+    Add code to helloworld:
+    char *p = rte_zmalloc(NULL, 9, 0);
+    if (!p) {
+        printf("rte_zmalloc error.");
+        return -1;
+    }
+    p[9] = 'a';
+
+The error log::
+
+    ==369953==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7fb17f465809 at pc 0x5652e6707b84 bp 0x7ffea70eea20 sp 0x7ffea70eea10 WRITE of size 1 at 0x7fb17f465809 thread T0
+    #0 0x5652e6707b83 in main ../examples/helloworld/main.c:47
+    #1 0x7fb94953c0b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
+    #2 0x5652e67079bd in _start (/home/pzh/asan_test/x86_64-native-linuxapp-gcc/examples/dpdk-helloworld+0x8329bd)
+
+    Address 0x7fb17f465809 is a wild pointer.
+    SUMMARY: AddressSanitizer: heap-buffer-overflow ../examples/helloworld/main.c:47 in main
+
+Example use-after-free error
+----------------------------
+
+Following error was reported when ASan was enabled::
+
+    Applied for 9 bytes of memory, and accessed the first byte after
+    released, so heap-use-after-free appeared.
+
+Below code results in this error::
+
+    Add code to helloworld:
+    char *p = rte_zmalloc(NULL, 9, 0);
+    if (!p) {
+        printf("rte_zmalloc error.");
+        return -1;
+    }
+    rte_free(p);
+    *p = 'a';
+
+The error log::
+
+    ==417048==ERROR: AddressSanitizer: heap-use-after-free on address 0x7fc83f465800 at pc 0x564308a39b89 bp 0x7ffc8c85bf50 sp 0x7ffc8c85bf40 WRITE of size 1 at 0x7fc83f465800 thread T0
+    #0 0x564308a39b88 in main ../examples/helloworld/main.c:48
+    #1 0x7fd0079c60b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
+    #2 0x564308a399bd in _start (/home/pzh/asan_test/x86_64-native-linuxapp-gcc/examples/dpdk-helloworld+0x8329bd)
+
+    Address 0x7fc83f465800 is a wild pointer.
+    SUMMARY: AddressSanitizer: heap-use-after-free ../examples/helloworld/main.c:48 in main
+
 Usage
 -----
 
@@ -35,6 +97,8 @@ Example usage::
 
 .. Note::
 
-  a) To compile with gcc in centos, libasan needs to be installed separately.
-  b) If the program being tested uses cmdline you will need to execute the
+  a) Some of the features of ASan (for example, 'Display memory application location, currently
+     displayed as a wild pointer') are not currently supported by DPDK's implementation.
+  b) To compile with gcc in centos, libasan needs to be installed separately.
+  c) If the program being tested uses cmdline you will need to execute the
      "stty echo" command when a error occurs.
diff --git a/lib/eal/common/malloc_elem.c b/lib/eal/common/malloc_elem.c
index c2c9461f1d..bdd20a162e 100644
--- a/lib/eal/common/malloc_elem.c
+++ b/lib/eal/common/malloc_elem.c
@@ -446,6 +446,8 @@ malloc_elem_alloc(struct malloc_elem *elem, size_t size, unsigned align,
 		struct malloc_elem *new_free_elem =
 				RTE_PTR_ADD(new_elem, size + MALLOC_ELEM_OVERHEAD);
 
+		asan_clear_split_alloczone(new_free_elem);
+
 		split_elem(elem, new_free_elem);
 		malloc_elem_free_list_insert(new_free_elem);
 
@@ -458,6 +460,8 @@ malloc_elem_alloc(struct malloc_elem *elem, size_t size, unsigned align,
 		elem->state = ELEM_BUSY;
 		elem->pad = old_elem_size;
 
+		asan_clear_alloczone(elem);
+
 		/* put a dummy header in padding, to point to real element header */
 		if (elem->pad > 0) { /* pad will be at least 64-bytes, as everything
 		                     * is cache-line aligned */
@@ -470,12 +474,18 @@ malloc_elem_alloc(struct malloc_elem *elem, size_t size, unsigned align,
 		return new_elem;
 	}
 
+	asan_clear_split_alloczone(new_elem);
+
 	/* we are going to split the element in two. The original element
 	 * remains free, and the new element is the one allocated.
 	 * Re-insert original element, in case its new size makes it
 	 * belong on a different list.
 	 */
+
 	split_elem(elem, new_elem);
+
+	asan_clear_alloczone(new_elem);
+
 	new_elem->state = ELEM_BUSY;
 	malloc_elem_free_list_insert(elem);
 
@@ -601,6 +611,8 @@ malloc_elem_hide_region(struct malloc_elem *elem, void *start, size_t len)
 	if (next && next_elem_is_adjacent(elem)) {
 		len_after = RTE_PTR_DIFF(next, hide_end);
 		if (len_after >= MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE) {
+			asan_clear_split_alloczone(hide_end);
+
 			/* split after */
 			split_elem(elem, hide_end);
 
@@ -615,6 +627,8 @@ malloc_elem_hide_region(struct malloc_elem *elem, void *start, size_t len)
 	if (prev && prev_elem_is_adjacent(elem)) {
 		len_before = RTE_PTR_DIFF(hide_start, elem);
 		if (len_before >= MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE) {
+			asan_clear_split_alloczone(hide_start);
+
 			/* split before */
 			split_elem(elem, hide_start);
 
@@ -628,6 +642,8 @@ malloc_elem_hide_region(struct malloc_elem *elem, void *start, size_t len)
 		}
 	}
 
+	asan_clear_alloczone(elem);
+
 	remove_elem(elem);
 }
 
@@ -641,8 +657,10 @@ malloc_elem_resize(struct malloc_elem *elem, size_t size)
 	const size_t new_size = size + elem->pad + MALLOC_ELEM_OVERHEAD;
 
 	/* if we request a smaller size, then always return ok */
-	if (elem->size >= new_size)
+	if (elem->size >= new_size) {
+		asan_clear_alloczone(elem);
 		return 0;
+	}
 
 	/* check if there is a next element, it's free and adjacent */
 	if (!elem->next || elem->next->state != ELEM_FREE ||
@@ -661,9 +679,15 @@ malloc_elem_resize(struct malloc_elem *elem, size_t size)
 		/* now we have a big block together. Lets cut it down a bit, by splitting */
 		struct malloc_elem *split_pt = RTE_PTR_ADD(elem, new_size);
 		split_pt = RTE_PTR_ALIGN_CEIL(split_pt, RTE_CACHE_LINE_SIZE);
+
+		asan_clear_split_alloczone(split_pt);
+
 		split_elem(elem, split_pt);
 		malloc_elem_free_list_insert(split_pt);
 	}
+
+	asan_clear_alloczone(elem);
+
 	return 0;
 }
 
diff --git a/lib/eal/common/malloc_elem.h b/lib/eal/common/malloc_elem.h
index a1e5f7f02c..a06c11ac8b 100644
--- a/lib/eal/common/malloc_elem.h
+++ b/lib/eal/common/malloc_elem.h
@@ -36,10 +36,20 @@ struct malloc_elem {
 	uint64_t header_cookie;         /* Cookie marking start of data */
 	                                /* trailer cookie at start + size */
 #endif
+#ifdef RTE_MALLOC_ASAN
+	size_t user_size;
+	uint64_t asan_cookie[2]; /* must be next to header_cookie */
+#endif
 } __rte_cache_aligned;
 
+static const unsigned int MALLOC_ELEM_HEADER_LEN = sizeof(struct malloc_elem);
+
 #ifndef RTE_MALLOC_DEBUG
-static const unsigned MALLOC_ELEM_TRAILER_LEN = 0;
+#ifdef RTE_MALLOC_ASAN
+static const unsigned int MALLOC_ELEM_TRAILER_LEN = RTE_CACHE_LINE_SIZE;
+#else
+static const unsigned int MALLOC_ELEM_TRAILER_LEN;
+#endif
 
 /* dummy function - just check if pointer is non-null */
 static inline int
@@ -55,7 +65,7 @@ set_trailer(struct malloc_elem *elem __rte_unused){ }
 
 
 #else
-static const unsigned MALLOC_ELEM_TRAILER_LEN = RTE_CACHE_LINE_SIZE;
+static const unsigned int MALLOC_ELEM_TRAILER_LEN = RTE_CACHE_LINE_SIZE;
 
 #define MALLOC_HEADER_COOKIE   0xbadbadbadadd2e55ULL /**< Header cookie. */
 #define MALLOC_TRAILER_COOKIE  0xadd2e55badbadbadULL /**< Trailer cookie.*/
@@ -90,9 +100,187 @@ malloc_elem_cookies_ok(const struct malloc_elem *elem)
 
 #endif
 
-static const unsigned MALLOC_ELEM_HEADER_LEN = sizeof(struct malloc_elem);
 #define MALLOC_ELEM_OVERHEAD (MALLOC_ELEM_HEADER_LEN + MALLOC_ELEM_TRAILER_LEN)
 
+#ifdef RTE_MALLOC_ASAN
+
+#ifdef RTE_ARCH_X86_64
+#define ASAN_SHADOW_OFFSET    0x00007fff8000
+#endif
+
+#define ASAN_SHADOW_GRAIN_SIZE	8
+#define ASAN_MEM_FREE_FLAG	0xfd
+#define ASAN_MEM_REDZONE_FLAG	0xfa
+#define ASAN_SHADOW_SCALE    3
+
+#define ASAN_MEM_SHIFT(mem) ((void *)((uintptr_t)(mem) >> ASAN_SHADOW_SCALE))
+#define ASAN_MEM_TO_SHADOW(mem) \
+	RTE_PTR_ADD(ASAN_MEM_SHIFT(mem), ASAN_SHADOW_OFFSET)
+
+#if defined(__clang__)
+__attribute__((no_sanitize("address", "hwaddress")))
+#else
+__attribute__((no_sanitize_address))
+#endif
+static inline void
+asan_set_shadow(void *addr, char val)
+{
+	*(char *)addr = val;
+}
+
+static inline void
+asan_set_zone(void *ptr, size_t len, uint32_t val)
+{
+	size_t offset, i;
+	void *shadow;
+	size_t zone_len = len / ASAN_SHADOW_GRAIN_SIZE;
+	if (len % ASAN_SHADOW_GRAIN_SIZE != 0)
+		zone_len += 1;
+
+	for (i = 0; i < zone_len; i++) {
+		offset = i * ASAN_SHADOW_GRAIN_SIZE;
+		shadow = ASAN_MEM_TO_SHADOW((uintptr_t)ptr + offset);
+		asan_set_shadow(shadow, val);
+	}
+}
+
+/*
+ * When the memory is released, the release mark is
+ * set in the corresponding range of the shadow area.
+ */
+static inline void
+asan_set_freezone(void *ptr, size_t size)
+{
+	asan_set_zone(ptr, size, ASAN_MEM_FREE_FLAG);
+}
+
+/*
+ * When the memory is allocated, memory state must set as accessible.
+ */
+static inline void
+asan_clear_alloczone(struct malloc_elem *elem)
+{
+	asan_set_zone((void *)elem, elem->size, 0x0);
+}
+
+static inline void
+asan_clear_split_alloczone(struct malloc_elem *elem)
+{
+	void *ptr = RTE_PTR_SUB(elem, MALLOC_ELEM_TRAILER_LEN);
+	asan_set_zone(ptr, MALLOC_ELEM_OVERHEAD, 0x0);
+}
+
+/*
+ * When the memory is allocated, the memory boundary is
+ * marked in the corresponding range of the shadow area.
+ * Requirement: redzone >= 16, is a power of two.
+ */
+static inline void
+asan_set_redzone(struct malloc_elem *elem, size_t user_size)
+{
+	uintptr_t head_redzone;
+	uintptr_t tail_redzone;
+	void *front_shadow;
+	void *tail_shadow;
+	uint32_t val;
+
+	if (elem != NULL) {
+		if (elem->state != ELEM_PAD)
+			elem = RTE_PTR_ADD(elem, elem->pad);
+
+		elem->user_size = user_size;
+
+		/* Set mark before the start of the allocated memory */
+		head_redzone = (uintptr_t)RTE_PTR_ADD(elem,
+			MALLOC_ELEM_HEADER_LEN - ASAN_SHADOW_GRAIN_SIZE);
+		front_shadow = ASAN_MEM_TO_SHADOW(head_redzone);
+		asan_set_shadow(front_shadow, ASAN_MEM_REDZONE_FLAG);
+		front_shadow = ASAN_MEM_TO_SHADOW(head_redzone
+			- ASAN_SHADOW_GRAIN_SIZE);
+		asan_set_shadow(front_shadow, ASAN_MEM_REDZONE_FLAG);
+
+		/* Set mark after the end of the allocated memory */
+		tail_redzone = (uintptr_t)RTE_PTR_ADD(elem,
+			MALLOC_ELEM_HEADER_LEN
+			+ elem->user_size);
+		tail_shadow = ASAN_MEM_TO_SHADOW(tail_redzone);
+		val = (tail_redzone % ASAN_SHADOW_GRAIN_SIZE);
+		val = (val == 0) ? ASAN_MEM_REDZONE_FLAG : val;
+		asan_set_shadow(tail_shadow, val);
+		tail_shadow = ASAN_MEM_TO_SHADOW(tail_redzone
+			+ ASAN_SHADOW_GRAIN_SIZE);
+		asan_set_shadow(tail_shadow, ASAN_MEM_REDZONE_FLAG);
+	}
+}
+
+/*
+ * When the memory is released, the mark of the memory boundary
+ * in the corresponding range of the shadow area is cleared.
+ * Requirement: redzone >= 16, is a power of two.
+ */
+static inline void
+asan_clear_redzone(struct malloc_elem *elem)
+{
+	uintptr_t head_redzone;
+	uintptr_t tail_redzone;
+	void *head_shadow;
+	void *tail_shadow;
+
+	if (elem != NULL) {
+		elem = RTE_PTR_ADD(elem, elem->pad);
+
+		/* Clear mark before the start of the allocated memory */
+		head_redzone = (uintptr_t)RTE_PTR_ADD(elem,
+			MALLOC_ELEM_HEADER_LEN - ASAN_SHADOW_GRAIN_SIZE);
+		head_shadow = ASAN_MEM_TO_SHADOW(head_redzone);
+		asan_set_shadow(head_shadow, 0x00);
+		head_shadow = ASAN_MEM_TO_SHADOW(head_redzone
+				- ASAN_SHADOW_GRAIN_SIZE);
+		asan_set_shadow(head_shadow, 0x00);
+
+		/* Clear mark after the end of the allocated memory */
+		tail_redzone = (uintptr_t)RTE_PTR_ADD(elem,
+			MALLOC_ELEM_HEADER_LEN + elem->user_size);
+		tail_shadow = ASAN_MEM_TO_SHADOW(tail_redzone);
+		asan_set_shadow(tail_shadow, 0x00);
+		tail_shadow = ASAN_MEM_TO_SHADOW(tail_redzone
+				+ ASAN_SHADOW_GRAIN_SIZE);
+		asan_set_shadow(tail_shadow, 0x00);
+	}
+}
+
+static inline size_t
+old_malloc_size(struct malloc_elem *elem)
+{
+	if (elem->state != ELEM_PAD)
+		elem = RTE_PTR_ADD(elem, elem->pad);
+
+	return elem->user_size;
+}
+#else
+static inline void
+asan_set_freezone(void *ptr __rte_unused, size_t size __rte_unused) { }
+
+static inline void
+asan_clear_alloczone(struct malloc_elem *elem __rte_unused) { }
+
+static inline void
+asan_clear_split_alloczone(struct malloc_elem *elem __rte_unused) { }
+
+static inline void
+asan_set_redzone(struct malloc_elem *elem __rte_unused,
+					size_t user_size __rte_unused) { }
+
+static inline void
+asan_clear_redzone(struct malloc_elem *elem __rte_unused) { }
+
+static inline size_t
+old_malloc_size(struct malloc_elem *elem)
+{
+	return elem->size - elem->pad - MALLOC_ELEM_OVERHEAD;
+}
+#endif
+
 /*
  * Given a pointer to the start of a memory block returned by malloc, get
  * the actual malloc_elem header for that block.
diff --git a/lib/eal/common/malloc_heap.c b/lib/eal/common/malloc_heap.c
index ee400f38ec..775d6789df 100644
--- a/lib/eal/common/malloc_heap.c
+++ b/lib/eal/common/malloc_heap.c
@@ -237,6 +237,7 @@ heap_alloc(struct malloc_heap *heap, const char *type __rte_unused, size_t size,
 		unsigned int flags, size_t align, size_t bound, bool contig)
 {
 	struct malloc_elem *elem;
+	size_t user_size = size;
 
 	size = RTE_CACHE_LINE_ROUNDUP(size);
 	align = RTE_CACHE_LINE_ROUNDUP(align);
@@ -250,6 +251,8 @@ heap_alloc(struct malloc_heap *heap, const char *type __rte_unused, size_t size,
 
 		/* increase heap's count of allocated elements */
 		heap->alloc_count++;
+
+		asan_set_redzone(elem, user_size);
 	}
 
 	return elem == NULL ? NULL : (void *)(&elem[1]);
@@ -270,6 +273,8 @@ heap_alloc_biggest(struct malloc_heap *heap, const char *type __rte_unused,
 
 		/* increase heap's count of allocated elements */
 		heap->alloc_count++;
+
+		asan_set_redzone(elem, size);
 	}
 
 	return elem == NULL ? NULL : (void *)(&elem[1]);
@@ -841,6 +846,8 @@ malloc_heap_free(struct malloc_elem *elem)
 	if (!malloc_elem_cookies_ok(elem) || elem->state != ELEM_BUSY)
 		return -1;
 
+	asan_clear_redzone(elem);
+
 	/* elem may be merged with previous element, so keep heap address */
 	heap = elem->heap;
 	msl = elem->msl;
@@ -848,6 +855,9 @@ malloc_heap_free(struct malloc_elem *elem)
 
 	rte_spinlock_lock(&(heap->lock));
 
+	void *asan_ptr = RTE_PTR_ADD(elem, MALLOC_ELEM_HEADER_LEN + elem->pad);
+	size_t asan_data_len = elem->size - MALLOC_ELEM_OVERHEAD - elem->pad;
+
 	/* mark element as free */
 	elem->state = ELEM_FREE;
 
@@ -1001,6 +1011,8 @@ malloc_heap_free(struct malloc_elem *elem)
 
 	rte_mcfg_mem_write_unlock();
 free_unlock:
+	asan_set_freezone(asan_ptr, asan_data_len);
+
 	rte_spinlock_unlock(&(heap->lock));
 	return ret;
 }
diff --git a/lib/eal/common/rte_malloc.c b/lib/eal/common/rte_malloc.c
index 9d39e58c08..d0bec26920 100644
--- a/lib/eal/common/rte_malloc.c
+++ b/lib/eal/common/rte_malloc.c
@@ -162,6 +162,8 @@ rte_calloc(const char *type, size_t num, size_t size, unsigned align)
 void *
 rte_realloc_socket(void *ptr, size_t size, unsigned int align, int socket)
 {
+	size_t user_size;
+
 	if (ptr == NULL)
 		return rte_malloc_socket(NULL, size, align, socket);
 
@@ -171,6 +173,8 @@ rte_realloc_socket(void *ptr, size_t size, unsigned int align, int socket)
 		return NULL;
 	}
 
+	user_size = size;
+
 	size = RTE_CACHE_LINE_ROUNDUP(size), align = RTE_CACHE_LINE_ROUNDUP(align);
 
 	/* check requested socket id and alignment matches first, and if ok,
@@ -181,6 +185,9 @@ rte_realloc_socket(void *ptr, size_t size, unsigned int align, int socket)
 			RTE_PTR_ALIGN(ptr, align) == ptr &&
 			malloc_heap_resize(elem, size) == 0) {
 		rte_eal_trace_mem_realloc(size, align, socket, ptr);
+
+		asan_set_redzone(elem, user_size);
+
 		return ptr;
 	}
 
@@ -192,7 +199,7 @@ rte_realloc_socket(void *ptr, size_t size, unsigned int align, int socket)
 	if (new_ptr == NULL)
 		return NULL;
 	/* elem: |pad|data_elem|data|trailer| */
-	const size_t old_size = elem->size - elem->pad - MALLOC_ELEM_OVERHEAD;
+	const size_t old_size = old_malloc_size(elem);
 	rte_memcpy(new_ptr, ptr, old_size < size ? old_size : size);
 	rte_free(ptr);
 
-- 
2.25.1