Re: [dpdk-dev] [EXT] Re: [PATCH] eal/trace: fix coverity issues

[Sunil Kumar Kori <skori@marvell.com>]

Hello David,

Mentioned patch (http://patches.dpdk.org/patch/69467/ ) takes care of your input to resolve GCC 10 build.
Now I think, this patch is good to go. Please take care of this.  

Regards
Sunil Kumar Kori

>-----Original Message-----
>From: David Marchand <david.marchand@redhat.com>
>Sent: Monday, April 27, 2020 7:22 PM
>To: Sunil Kumar Kori <skori@marvell.com>
>Cc: Jerin Jacob Kollanukkaran <jerinj@marvell.com>; dev <dev@dpdk.org>
>Subject: Re: [EXT] Re: [dpdk-dev] [PATCH] eal/trace: fix coverity issues
>
>On Mon, Apr 27, 2020 at 3:46 PM Sunil Kumar Kori <skori@marvell.com>
>wrote:
>>
>> >-----Original Message-----
>> >From: David Marchand <david.marchand@redhat.com>
>> >Sent: Monday, April 27, 2020 5:56 PM
>> >To: Sunil Kumar Kori <skori@marvell.com>
>> >Cc: Jerin Jacob Kollanukkaran <jerinj@marvell.com>; dev
>> ><dev@dpdk.org>
>> >Subject: [EXT] Re: [dpdk-dev] [PATCH] eal/trace: fix coverity issues
>> >
>> >External Email
>> >
>> >---------------------------------------------------------------------
>> >- On Mon, Apr 27, 2020 at 2:04 PM Sunil Kumar Kori
>> ><skori@marvell.com>
>> >wrote:
>> >>
>> >> Pointer was being dereferenced without NULL checking.
>> >>
>> >> Coverity issue: 357768
>> >>
>> >> Fixes: 8c8066ea6a7b ("trace: add trace mode configuration
>> >> parameter")
>> >>
>> >> Signed-off-by: Sunil Kumar Kori <skori@marvell.com>
>> >> ---
>> >>  lib/librte_eal/common/eal_common_trace_utils.c | 3 ++-
>> >>  1 file changed, 2 insertions(+), 1 deletion(-)
>> >>
>> >> diff --git a/lib/librte_eal/common/eal_common_trace_utils.c
>> >> b/lib/librte_eal/common/eal_common_trace_utils.c
>> >> index fce8892c3..119e97119 100644
>> >> --- a/lib/librte_eal/common/eal_common_trace_utils.c
>> >> +++ b/lib/librte_eal/common/eal_common_trace_utils.c
>> >> @@ -227,15 +227,16 @@ int
>> >>  eal_trace_mode_args_save(const char *optarg)  {
>> >>         struct trace *trace = trace_obj_get();
>> >> -       size_t len = strlen(optarg);
>> >>         unsigned long tmp;
>> >>         char *pattern;
>> >> +       size_t len;
>> >>
>> >>         if (optarg == NULL) {
>> >>                 trace_err("no optarg is passed");
>> >>                 return -EINVAL;
>> >>         }
>> >>
>> >> +       len = strlen(optarg);
>> >>         if (len == 0) {
>> >>                 trace_err("value is not provided with option");
>> >>                 return -EINVAL;
>> >
>> >I was looking at some gcc 10 complaints on string manipulation later
>> >in eal_trace_dir_args_save().
>> >
>> >https://urldefense.proofpoint.com/v2/url?u=https-
>> >3A__build.opensuse.org_package_live-5Fbuild-5Flog_home-3Admarchan-
>> >3Abranches-3Ahome-3Abluca-3Adpdk_dpdk_Fedora-5FRawhide_x86-
>>
>>5F64&d=DwIFaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=dXeXaAMkP5COgn1zxHM
>y
>>
>>aF1_d9IIuq6vHQO6NrIPjaE&m=NZ72Sr2OMEYZD7PIY59lshlAxZJJJepF5oxbHv0
>j
>> >5Zg&s=yOCA3PfhZojqJv0iVKlzeqM7tYGVv0jjrnVcajUx_qA&e=
>> >
>> >[  126s]   CC rte_malloc.o
>> >[  127s] /home/abuild/rpmbuild/BUILD/dpdk-
>> >1587835122.b13ace300/lib/librte_eal/common/eal_common_trace_utils.c:
>> >In function 'eal_trace_dir_args_save':
>> >[  127s] /home/abuild/rpmbuild/BUILD/dpdk-
>>
>>1587835122.b13ace300/lib/librte_eal/common/eal_common_trace_utils.c:2
>> >9
>> >0:24:
>> >error: 'sprintf' may write a terminating nul past the end of the
>> >destination [-Werror=format-overflow=]
>> >[  127s]   290 |  sprintf(dir_path, "%s/", optarg);
>> >[  127s]       |                        ^
>> >[  127s] /home/abuild/rpmbuild/BUILD/dpdk-
>>
>>1587835122.b13ace300/lib/librte_eal/common/eal_common_trace_utils.c:2
>> >9
>> >0:2:
>> >note: 'sprintf' output between 2 and 4097 bytes into a destination of
>> >size 4096
>> >[  127s]   290 |  sprintf(dir_path, "%s/", optarg);
>> >[  127s]       |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> >[  127s] cc1: all warnings being treated as errors
>> >
>> >
>> >Could we use asprintf in all this code and avoid malloc + sprintf ?
>> >
>> As I understood from above warnings/errors, real problem is writing beyond
>destination i.e. dir_path.
>> If this is the case then it can be simply handled using snprintf(); with correct
>"size" information.
>> Suggested code changes are correct. I am just trying to achieve this with
>lesser code changes.
>>
>> Also I think, fix for this should be a separate patch.
>> Suggestions please ?
>
>If the code was not combining this malloc + sprintf + wrong checks (caught by
>coverity), we would avoid both issues and it would be more consistent.
>No more suggestion from me.
>
>
>--
>David Marchand