From: "Dumitrescu, Cristian" <cristian.dumitrescu@intel.com>
To: "Jastrzebski, MichalX K" <michalx.k.jastrzebski@intel.com>,
"Zhang, Roy Fan" <roy.fan.zhang@intel.com>,
"Singh, Jasvinder" <jasvinder.singh@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"Mrozowicz, SlawomirX" <slawomirx.mrozowicz@intel.com>
Subject: Re: [dpdk-dev] [PATCH v3] examples/qos_sched: fix bad bit shift operation
Date: Thu, 28 Apr 2016 11:16:23 +0000 [thread overview]
Message-ID: <3EB4FA525960D640B5BDFFD6A3D89126479A6F2B@IRSMSX108.ger.corp.intel.com> (raw)
In-Reply-To: <1461244093-2008-3-git-send-email-michalx.k.jastrzebski@intel.com>
> -----Original Message-----
> From: Jastrzebski, MichalX K
> Sent: Thursday, April 21, 2016 2:08 PM
> To: Dumitrescu, Cristian <cristian.dumitrescu@intel.com>; Zhang, Roy Fan
> <roy.fan.zhang@intel.com>; Singh, Jasvinder <jasvinder.singh@intel.com>
> Cc: dev@dpdk.org; Mrozowicz, SlawomirX
> <slawomirx.mrozowicz@intel.com>
> Subject: [PATCH v3] examples/qos_sched: fix bad bit shift operation
>
> From: Slawomir Mrozowicz <slawomirx.mrozowicz@intel.com>
>
> Fix issue reported by Coverity.
>
> Coverity ID 30690: Bad bit shift operation
> large_shift: In expression 1ULL << i, left shifting by more than 63 bits
> has undefined behavior. The shift amount, i, is as much as 127.
>
> Fixes: de3cfa2c9823 ("sched: initial import")
>
> Signed-off-by: Slawomir Mrozowicz <slawomirx.mrozowicz@intel.com>
> ---
> examples/qos_sched/args.c | 84 +++++++++++++++++++++++++++++------
> ------------
> 1 file changed, 52 insertions(+), 32 deletions(-)
>
> diff --git a/examples/qos_sched/args.c b/examples/qos_sched/args.c
> index 3e7fd08..cd077ba 100644
> --- a/examples/qos_sched/args.c
> +++ b/examples/qos_sched/args.c
> @@ -53,7 +53,7 @@
>
> static uint32_t app_master_core = 1;
> static uint32_t app_numa_mask;
> -static uint64_t app_used_core_mask = 0;
> +static int app_used_core_mask[RTE_MAX_LCORE];
> static uint64_t app_used_port_mask = 0;
> static uint64_t app_used_rx_port_mask = 0;
> static uint64_t app_used_tx_port_mask = 0;
> @@ -115,22 +115,23 @@ static inline int str_is(const char *str, const char *is)
> return strcmp(str, is) == 0;
> }
>
> -/* returns core mask used by DPDK */
> -static uint64_t
> -app_eal_core_mask(void)
> +/* compare used core with eal configuration,
> + returns:
> + 1 if equal
> + 0 if differ */
> +static int
> +app_eal_core_check(void)
> {
> - uint32_t i;
> - uint64_t cm = 0;
> + uint16_t i;
> + int ret = 1;
> struct rte_config *cfg = rte_eal_get_configuration();
>
> - for (i = 0; i < RTE_MAX_LCORE; i++) {
> - if (cfg->lcore_role[i] == ROLE_RTE)
> - cm |= (1ULL << i);
> + for (i = 0; i < RTE_MAX_LCORE && ret; i++) {
> + if ((cfg->lcore_role[i] == ROLE_RTE) !=
> app_used_core_mask[i])
> + ret = 0;
> }
>
> - cm |= (1ULL << cfg->master_lcore);
> -
> - return cm;
> + return ret;
> }
>
>
> @@ -292,14 +293,9 @@ app_parse_flow_conf(const char *conf_str)
> app_used_tx_port_mask |= mask;
> app_used_port_mask |= mask;
>
> - mask = 1lu << pconf->rx_core;
> - app_used_core_mask |= mask;
> -
> - mask = 1lu << pconf->wt_core;
> - app_used_core_mask |= mask;
> -
> - mask = 1lu << pconf->tx_core;
> - app_used_core_mask |= mask;
> + app_used_core_mask[pconf->rx_core] = 1;
> + app_used_core_mask[pconf->wt_core] = 1;
> + app_used_core_mask[pconf->tx_core] = 1;
>
> nb_pfc++;
>
> @@ -335,7 +331,7 @@ app_parse_args(int argc, char **argv)
> int option_index;
> const char *optname;
> char *prgname = argv[0];
> - uint32_t i, nb_lcores;
> + uint16_t i, j, k, nb_lcores;
>
> static struct option lgopts[] = {
> { "pfc", 1, 0, 0 },
> @@ -349,6 +345,9 @@ app_parse_args(int argc, char **argv)
> { NULL, 0, 0, 0 }
> };
>
> + for (i = 0; i < RTE_MAX_LCORE; i++)
> + app_used_core_mask[i] = 0;
> +
> /* initialize EAL first */
> ret = rte_eal_init(argc, argv);
> if (ret < 0)
> @@ -436,19 +435,40 @@ app_parse_args(int argc, char **argv)
> }
>
> /* check master core index validity */
> - for(i = 0; i <= app_master_core; i++) {
> - if (app_used_core_mask & (1u << app_master_core)) {
> - RTE_LOG(ERR, APP, "Master core index is not
> configured properly\n");
> - app_usage(prgname);
> - return -1;
> - }
> + if (app_used_core_mask[app_master_core] == 1) {
> + RTE_LOG(ERR, APP,
> + "Master core index is not configured properly\n");
> + app_usage(prgname);
> + return -1;
> }
> - app_used_core_mask |= 1u << app_master_core;
> + app_used_core_mask[app_master_core] = 1;
> +
> + if ((app_eal_core_check() == 0) ||
> + (app_master_core != rte_get_master_lcore())) {
> +
> + char used_hexstr[RTE_MAX_LCORE/4+1];
> + char conf_hexstr[RTE_MAX_LCORE/4+1];
> + int used_byte, conf_byte;
> + struct rte_config *cfg = rte_eal_get_configuration();
> +
> + for (i = 0; i < RTE_MAX_LCORE/4; i++) {
> + used_byte = 0;
> + conf_byte = 0;
> + for (j = 0; j < 3; j++) {
> + k = 4 * (RTE_MAX_LCORE/4 - i - 1) + j;
> + used_byte += app_used_core_mask[k] << j;
> + conf_byte +=
> + ((cfg->lcore_role[k] ==
> + ROLE_RTE)?1:0) << j;
> + }
> + sprintf(&used_hexstr[i], "%1x", used_byte);
> + sprintf(&conf_hexstr[i], "%1x", used_byte);
> + }
> +
> + RTE_LOG(ERR, APP, "EAL core mask not configured
> properly\n");
> + RTE_LOG(ERR, APP, " must be : %s\n", used_hexstr);
> + RTE_LOG(ERR, APP, " instead of: %s\n", conf_hexstr);
>
> - if ((app_used_core_mask != app_eal_core_mask()) ||
> - (app_master_core != rte_get_master_lcore())) {
> - RTE_LOG(ERR, APP, "EAL core mask not configured properly,
> must be %" PRIx64
> - " instead of %" PRIx64 "\n" ,
> app_used_core_mask, app_eal_core_mask());
> return -1;
> }
>
> --
> 1.9.1
Can you please explain the root issue?
This patch contains way too much code for fixing a shift overflow issue, it is basically a rework without explaining the issue or reason/benefit for the rework.
This approach does not look right to me, I am sure there is a better and quicker way to fix the potential issue once we all understand it.
next prev parent reply other threads:[~2016-04-28 11:16 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-21 13:08 [dpdk-dev] [PATCH v3] examples/qos_sched: fix negative loop bound Michal Jastrzebski
2016-04-21 13:08 ` [dpdk-dev] [PATCH v3] examples/qos_sched: fix copy-paste error Michal Jastrzebski
2016-04-28 11:00 ` Dumitrescu, Cristian
2016-05-16 16:16 ` Thomas Monjalon
2016-04-21 13:08 ` [dpdk-dev] [PATCH v3] examples/qos_sched: fix bad bit shift operation Michal Jastrzebski
2016-04-28 11:16 ` Dumitrescu, Cristian [this message]
2016-05-10 9:39 ` Mrozowicz, SlawomirX
2016-05-10 9:45 ` Dumitrescu, Cristian
2016-04-28 10:59 ` [dpdk-dev] [PATCH v3] examples/qos_sched: fix negative loop bound Dumitrescu, Cristian
2016-05-16 16:02 ` Thomas Monjalon
2016-05-10 12:20 [dpdk-dev] [PATCH v3] examples/qos_sched: fix bad bit shift operation Slawomir Mrozowicz
2016-05-10 17:25 ` Dumitrescu, Cristian
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