Re: [dpdk-dev] [PATCH v4 1/2] Enable ASan for memory detector on DPDK

[Olivier Matz <olivier.matz@6wind.com>]

Hi Zhihong,

On Fri, Sep 24, 2021 at 02:16:29AM +0000, zhihongx.peng@intel.com wrote:
> 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.
> 
> By referring to its implementation algorithm
> (https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm),
> enable heap-buffer-overflow and use-after-free functions on dpdk.
> DPDK ASan function currently only supports on 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';
>         ......
> 
> If you want to use this feature,
> you need to add below compilation options when compiling code:
> -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.
> 
> Note:
> a) The issue of ASan wild pointer is that dpdk ASan tool is not fully
> adapted to google ASan. For example: Address 0x7fe2ffafa240 is a wild
> pointer.
> b) Centos needs to install libasan separately.
> c) If the program uses DPDK cmdline, when a memory bug occurs, need
> to execute the "stty echo" command.
> 
> Signed-off-by: Xueqin Lin <xueqin.lin@intel.com>
> Signed-off-by: Zhihong Peng <zhihongx.peng@intel.com>

Thank you for this patch, this looks quite useful.

Do you know what is the performance impact of enabling ASan?

Do you think a similar approach could be applied to mempools?

Regards,
Olivier