[dpdk-users] 【dpdk eal parameter parse issue check】

Shen, Chuanpeng (NSB - CN/Hangzhou) chuanpeng.shen at nokia-sbell.com
Thu Jan 17 13:38:50 CET 2019


Hi,
DPDK experts, I need your help since I meet a problem when using DPDK interface rte_eal_init in eal.c

We added some more debug logs with some modification and we can see that when we are sending a dynamically allocated char* array to dpdk api(rte_eal_init) directly it's changing/corrupting some pointers which is creating issue later while freeing the memory.

● char* array ---> rte_eal_init ---> changing/corrupting some pointers

#  /opt/nokia/tools/SS_RCPDPM/tools/dpm_diag_cli memstats -P ALL -F

memory allocated for index 0 ptr 0x624690

memory allocated for index 1 ptr 0x624ad0

memory allocated for index 2 ptr 0x624b00

memory allocated for index 3 ptr 0x624b30

memory allocated for index 4 ptr 0x624b60

memory allocated for index 5 ptr 0x624b90

memory allocated for index 6 ptr 0x624bc0

memory allocated for index 7 ptr 0x624bf0

memory allocated for index 8 ptr 0x624c20

memory allocated for index 9 ptr 0x624c50

attach for index 0 ptr 0x624690

attach for index 1 ptr 0x624ad0

attach for index 2 ptr 0x624b00

attach for index 3 ptr 0x624b30

attach for index 4 ptr 0x624b60

attach for index 5 ptr 0x624b90

attach for index 6 ptr 0x624bc0

attach for index 7 ptr 0x624bf0

attach for index 8 ptr 0x624690 --------------It seems this is pointing to first(0th index) now. So latter when we try to free it says double free as 0th index is already freed.

attach for index 9 ptr 0x624c50
And the root cause is show below.

@ eal.c

static int

eal_parse_args(int argc, char **argv)

{

    int opt, ret;

    char **argvopt;

    int option_index;

    char *prgname = argv[0];

    const int old_optind = optind;

    const int old_optopt = optopt;

    char * const old_optarg = optarg;

    int islocal_config = 0;

    int num_para = 0;



    argvopt = argv;

    optind = 1;



    while ((opt = getopt_long(argc, argvopt, eal_short_options,

                eal_long_options, &option_index)) != EOF) {



       …



    if (optind >= 0) --- ● when call getopt_long the optind will ++ and at this case the optind is 9 at this time, so the argv[8] will be changed as argv[0]. This is the original DPDK code.

       argv[optind-1] = prgname;

    ret = optind-1;



out:

    /* restore getopt lib */

    optind = old_optind;

    optopt = old_optopt;

    optarg = old_optarg;



    return ret;

}

My question is what the code below actually supposed to be used for? Thanks!

if (optind >= 0)

       argv[optind-1] = prgname;

    ret = optind-1;



------------------------------------
Shen Chuanpeng
Tel  : 15858127547
Seat : 17066
------------------------------------



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