Re: [dpdk-dev] [PATCH v6 1/2] Enable ASan for memory detector on DPDK

["Peng, ZhihongX" <zhihongx.peng@intel.com>]

> -----Original Message-----
> From: Richardson, Bruce <bruce.richardson@intel.com>
> Sent: Wednesday, October 13, 2021 4:00 PM
> To: David Marchand <david.marchand@redhat.com>
> Cc: Peng, ZhihongX <zhihongx.peng@intel.com>; Burakov, Anatoly
> <anatoly.burakov@intel.com>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; Stephen Hemminger
> <stephen@networkplumber.org>; dev <dev@dpdk.org>; Lin, Xueqin
> <xueqin.lin@intel.com>; Thomas Monjalon <thomas@monjalon.net>
> Subject: Re: [dpdk-dev] [PATCH v6 1/2] Enable ASan for memory detector on
> DPDK
> 
> On Thu, Sep 30, 2021 at 10:20:00AM +0200, David Marchand wrote:
> > Hello,
> >
> > I see v6 is superseded in pw, I have been cleaning my queue... maybe my
> fault.
> >
> >
> > On Thu, Sep 30, 2021 at 7:37 AM <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.
> > >
> > > `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.
> >
> > This patch mixes how to use ASan and instrumenting the DPDK mem
> allocator.
> >
> > I would split this patch in two.
> >
> > The first patch can add the documentation on enabling/using ASan and
> > describe the known issues on enabling it.
> > I'd find it better (from a user pov) if we hide all those details
> > about b_lundef and installation of libasan on Centos.
> >
> > Something like (only quickly tested):
> >
> > diff --git a/config/meson.build b/config/meson.build index
> > 4cdf589e20..7d8b71da79 100644
> > --- a/config/meson.build
> > +++ b/config/meson.build
> > @@ -411,6 +411,33 @@ if get_option('b_lto')
> >      endif
> >  endif
> >
> > +if get_option('b_sanitize') == 'address'
> > +    asan_dep = cc.find_library('asan', required: true)
> > +    if (not cc.links('int main(int argc, char *argv[]) { return 0; }',
> > +                     dependencies: asan_dep))
> > +        error('broken dependency, "libasan"')
> > +    endif
> > +    add_project_link_arguments('-lasan', language: 'c')
> > +    dpdk_extra_ldflags += '-lasan'
> > +endif
> > +
> >  if get_option('default_library') == 'both'
> >      error( '''
> >   Unsupported value "both" for "default_library" option.
> >
> >
> > Bruce, do you see an issue with this approach?
> >
> 
> Apologies for delayed reply on this.
> 
> No issue with this approach on my end, seems reasonable. Just watch out
> that b_sanitize can have "address,undefined" as a possible value, so if we
> want to support that, we can't just check directly for the literal string
> "address"
> 
> >
> > Then a second patch adds the rte_malloc instrumentation, with a check
> > at configuration time.
> >
> >      endif
> >      add_project_link_arguments('-lasan', language: 'c')
> >      dpdk_extra_ldflags += '-lasan'
> > +    if arch_subdir == 'x86'
> > +        asan_check_code = '''
> > +#ifdef __SANITIZE_ADDRESS__
> > +#define RTE_MALLOC_ASAN
> > +#elif defined(__has_feature)
> > +# if __has_feature(address_sanitizer) #define RTE_MALLOC_ASAN #
> endif
> > +#endif
> > +
> > +#ifndef RTE_MALLOC_ASAN
> > +#error ASan not available.
> > +#endif
> > +'''
> > +        if cc.compiles(asan_check_code)
> > +            dpdk_conf.set10('RTE_MALLOC_ASAN', true)
> > +        endif
> > +    endif
> >  endif
> >
> 
> Apologies, but I haven't been tracking this set in much detail.
> Do we really need this second configuration check? Should it, or could it, be
> merged into the check above for the asan library presence?
> 

All code:
if get_option('b_sanitize') == 'address' or get_option('b_sanitize') == 'undefined'
    if cc.get_id() == 'gcc'
        asan_dep = cc.find_library('asan', required: true)
        if (not cc.links('int main(int argc, char *argv[]) { return 0; }',
                    dependencies: asan_dep))
            error('broken dependency, "libasan"')
        endif
    endif

    if exec_env == 'linux' and arch_subdir == 'x86'
        dpdk_conf.set10('RTE_MALLOC_ASAN', true)
    endif
endif

Bruce, is this code correct?
Thanks!
> /Bruce