[dpdk-dev] [PATCH v7 1/3] Enable ASan for memory detector on DPDK

[zhihongx.peng@intel.com]

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

AddressSanitizer (ASan) is a google memory error detect
standard tool. It could help to detect use-after-free and
{heap,stack,global}-buffer overflow bugs in C/C++ programs,
print detailed error information when error happens, large
improve debug efficiency.

`AddressSanitizer
<https://github.com/google/sanitizers/wiki/AddressSanitizer>` (ASan)
is a widely-used debugging tool to detect memory access errors.
It helps detect issues like use-after-free, various kinds of buffer
overruns in C/C++ programs, and other similar errors, as well as
printing out detailed debug information whenever an error is detected.

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.

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';
        ......

We can enable ASan by adding below compilation options:
-Dbuildtype=debug -Db_lundef=false -Db_sanitize=address
"-Dbuildtype=debug": This is a non-essential option. When this option
is added, if a memory error occurs, ASan can clearly show where the
code is wrong.
"-Db_lundef=false": When use clang to compile DPDK, this option must
be added.

Signed-off-by: Xueqin Lin <xueqin.lin@intel.com>
Signed-off-by: Zhihong Peng <zhihongx.peng@intel.com>
---
 devtools/words-case.txt         |   1 +
 doc/guides/prog_guide/asan.rst  | 100 ++++++++++++++++++++++++++++++++
 doc/guides/prog_guide/index.rst |   1 +
 3 files changed, 102 insertions(+)
 create mode 100644 doc/guides/prog_guide/asan.rst

diff --git a/devtools/words-case.txt b/devtools/words-case.txt
index 0bbad48626..ada6910fa0 100644
--- a/devtools/words-case.txt
+++ b/devtools/words-case.txt
@@ -5,6 +5,7 @@ API
 Arm
 armv7
 armv8
+ASan
 BAR
 CRC
 DCB
diff --git a/doc/guides/prog_guide/asan.rst b/doc/guides/prog_guide/asan.rst
new file mode 100644
index 0000000000..fb48b9f10b
--- /dev/null
+++ b/doc/guides/prog_guide/asan.rst
@@ -0,0 +1,100 @@
+.. Copyright (c) <2021>, Intel Corporation
+   All rights reserved.
+
+Memory error detect standard tool - AddressSanitizer(ASan)
+==========================================================
+
+AddressSanitizer (ASan) is a google memory error detect
+standard tool. It could help to detect use-after-free and
+{heap,stack,global}-buffer overflow bugs in C/C++ programs,
+print detailed error information when error happens, large
+improve debug efficiency.
+
+By referring to its implementation algorithm
+(https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm),
+enabled heap-buffer-overflow and use-after-free functions on DPDK.
+DPDK ASan function currently only supports on Linux x86_64.
+
+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.
+
+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
+-----
+
+meson build
+^^^^^^^^^^^
+
+To enable ASan in meson build system, use following meson build command:
+
+Example usage::
+
+ meson build -Dbuildtype=debug -Db_lundef=false -Db_sanitize=address
+ ninja -C build
+
+.. Note::
+
+  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) DPDK test has been completed in ubuntu18.04/ubuntu20.04/redhat8.3. Centos needs to install
+     libasan separately.
+  c) If the program uses cmdline, when a memory bug occurs, need to execute the "stty echo" command.
diff --git a/doc/guides/prog_guide/index.rst b/doc/guides/prog_guide/index.rst
index 2dce507f46..df8a4b93e1 100644
--- a/doc/guides/prog_guide/index.rst
+++ b/doc/guides/prog_guide/index.rst
@@ -71,3 +71,4 @@ Programmer's Guide
     lto
     profile_app
     glossary
+    asan
-- 
2.25.1