On Tue, Oct 12, 2021 at 11:54 AM [off-list ref] wrote:

From: Zhihong Peng <redacted>

`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.

Comments below concern added feature with patch 2.
From here...

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';
        ......

... to here.

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 <redacted>
Signed-off-by: Zhihong Peng <redacted>

More problematic, linking an external (out of meson) application to a
dpdk compiled with ASan is broken.

My environment contains following targets compiled using
./devtools/test-meson-builds.sh:
$ ls $HOME/builds/
build-arm64-bluefield  build-arm64-host-clang  build-clang-shared
build-gcc-shared  build-ppc64le-power8  build-x86-mingw
build-arm64-dpaa       build-arm64-octeontx2   build-clang-static
build-gcc-static  build-x86-generic

I stopped at patch 1, configured following target to have ASan in
them, like this:

$ meson configure $HOME/builds/build-gcc-static -Db_sanitize=address
$ meson configure $HOME/builds/build-clang-shared -Db_sanitize=address
-Db_lundef=false
$ meson configure $HOME/builds/build-x86-generic -Db_sanitize=address
                               ^^^^^^^^^^^^^^^^^
                               This is the target for which we test
linking a dpdk application out of meson.

$ meson configure $HOME/builds/build-arm64-bluefield -Db_sanitize=address

Then ran the check:
$ ./devtools/test-meson-builds.sh
...
...
...
## Building cmdline
/usr/bin/ld: /usr/lib64/libasan.so.6: warning: the use of `tmpnam' is
dangerous, better use `mkstemp'
/usr/bin/ld: /usr/lib64/libasan.so.6: warning: the use of `tempnam' is
dangerous, better use `mkstemp'
/usr/bin/ld: /usr/lib64/libasan.so.6: warning: the use of `tmpnam_r'
is dangerous, better use `mkstemp'
## Building helloworld
/usr/bin/ld: /usr/lib64/libasan.so.6: warning: the use of `tmpnam' is
dangerous, better use `mkstemp'
/usr/bin/ld: /usr/lib64/libasan.so.6: warning: the use of `tempnam' is
dangerous, better use `mkstemp'
/usr/bin/ld: /usr/lib64/libasan.so.6: warning: the use of `tmpnam_r'
is dangerous, better use `mkstemp'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/install/usr/local/lib/librte_common_dpaax.a(common_dpaax_dpaax_iova_table.c.o):
in function `read_memory_node':
/home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:57:
undefined reference to `__asan_option_detect_stack_use_after_return'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:65:
undefined reference to `__asan_report_store4'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:61:
undefined reference to `__asan_report_store_n'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:60:
undefined reference to `__asan_report_store_n'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:57:
undefined reference to `__asan_stack_malloc_3'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:77:
undefined reference to `__asan_report_load8'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:86:
undefined reference to `__asan_report_load8'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:86:
undefined reference to `__asan_report_load8'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:88:
undefined reference to `__asan_report_load8'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:88:
undefined reference to `__asan_report_load8'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/install/usr/local/lib/librte_common_dpaax.a(common_dpaax_dpaax_iova_table.c.o):/home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:102:
more undefined references to `__asan_report_load8' follow
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/install/usr/local/lib/librte_common_dpaax.a(common_dpaax_dpaax_iova_table.c.o):
in function `read_memory_node':
/home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:119:
undefined reference to `__asan_report_store4'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:145:
undefined reference to `__asan_report_load16'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:135:
undefined reference to `__asan_report_store_n'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:143:
undefined reference to `__asan_report_load8'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/install/usr/local/lib/librte_common_dpaax.a(common_dpaax_dpaax_iova_table.c.o):
in function `rotate_8':
/home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:40:
undefined reference to `__asan_report_store4'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:39:
undefined reference to `__asan_report_store4'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:40:
undefined reference to `__asan_report_store4'
/usr/bin/ld: /home/dmarchan/builds/build-x86-generic/install/usr/local/lib/librte_common_dpaax.a(common_dpaax_dpaax_iova_table.c.o):
in function `read_memory_node':
/home/dmarchan/builds/build-x86-generic/../../dpdk/drivers/common/dpaax/dpaax_iova_table.c:143:
undefined reference to `__asan_report_load8'
*flood of errors about undefined symbols from libasan*


Tried to debug, in-tree compiled testpmd shows:
$ readelf -d $HOME/builds/build-x86-generic/app/dpdk-testpmd | grep asan
 0x0000000000000001 (NEEDED)             Shared library: [libasan.so.6]
But I see nothing in ninja:
$ grep -i asan $HOME/builds/build-x86-generic/build.ninja

And for external link, looking at an "installed" .pc:
$ PKG_CONFIG_PATH=/home/dmarchan/builds/build-x86-generic/install/usr/local/lib/pkgconfig
pkg-config libdpdk --libs | grep asan



Some more comments about splitting doc with patch2:

Same problem, below should be in patch 2, from here...

+
+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

... till here.

+
+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

l_undef unnecessary for gcc.

+ 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.

This comment should be in patch 2, there is nothing specific in patch
1 about DPDK wrt ASan.

-- 
David Marchand