Re: [PATCH v3 3/8] eal: change several log levels matching a regexp

["Tan, Jianfeng" <jianfeng.tan@intel.com>]

Hi Olivier,


On 4/5/2017 12:40 AM, Olivier Matz wrote:
> Introduce a function to set the log level of several log types that
> match a regular expression.
>
> Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
> ---
>   lib/librte_eal/bsdapp/eal/rte_eal_version.map   |  1 +
>   lib/librte_eal/common/eal_common_log.c          | 21 +++++++++++++++++++++
>   lib/librte_eal/common/include/rte_log.h         | 12 ++++++++++++
>   lib/librte_eal/linuxapp/eal/rte_eal_version.map |  1 +
>   4 files changed, 35 insertions(+)
>
> diff --git a/lib/librte_eal/bsdapp/eal/rte_eal_version.map b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
> index bd63ea66b..de74ff9ff 100644
> --- a/lib/librte_eal/bsdapp/eal/rte_eal_version.map
> +++ b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
> @@ -189,5 +189,6 @@ DPDK_17.05 {
>   	rte_log_dump;
>   	rte_log_register;
>   	rte_log_set_level;
> +	rte_log_set_level_regexp;
>   
>   } DPDK_17.02;
> diff --git a/lib/librte_eal/common/eal_common_log.c b/lib/librte_eal/common/eal_common_log.c
> index 90326215b..d02689390 100644
> --- a/lib/librte_eal/common/eal_common_log.c
> +++ b/lib/librte_eal/common/eal_common_log.c
> @@ -37,6 +37,7 @@
>   #include <stdlib.h>
>   #include <string.h>
>   #include <errno.h>
> +#include <regex.h>
>   
>   #include <rte_eal.h>
>   #include <rte_log.h>
> @@ -132,6 +133,26 @@ rte_log_set_level(uint32_t type, uint32_t level)
>   	return 0;
>   }
>   
> +/* set level */
> +int
> +rte_log_set_level_regexp(const char *pattern, uint32_t level)
> +{
> +	regex_t r;
> +	size_t i;
> +
> +	if (level > RTE_LOG_DEBUG)
> +		return -1;
> +
> +	for (i = 0; i < rte_logs.dynamic_types_len; i++) {
> +		if (rte_logs.dynamic_types[i].name == NULL)
> +			continue;
> +		if (regexec(&r, pattern, 0, NULL, 0) == 0)
> +			rte_logs.dynamic_types[i].loglevel = level;

When I try this option, it causes segment fault. The problem might lie 
in this function. As far as I know, when we use regexec(), we need to 
compile a regular expression firstly using regcomp(); and then call 
regexec() with the compiled pattern with the full string. In other words:

         regcomp(&r, pattern, 0);
         for (i = 0; i < rte_logs.dynamic_types_len; i++) {
                 ...
                if (regexec(&r, rte_logs.dynamic_types[i].name, 0, NULL, 
0) == 0)
                         rte_logs.dynamic_types[i].loglevel = level;
         }

Thanks,
Jianfeng

> +	}
> +
> +	return 0;
> +}
> +
>   /* get the current loglevel for the message beeing processed */
>   int rte_log_cur_msg_loglevel(void)
>   {
> diff --git a/lib/librte_eal/common/include/rte_log.h b/lib/librte_eal/common/include/rte_log.h
> index 97e0c5e52..ce48b0785 100644
> --- a/lib/librte_eal/common/include/rte_log.h
> +++ b/lib/librte_eal/common/include/rte_log.h
> @@ -157,6 +157,18 @@ uint32_t rte_get_log_type(void);
>   /**
>    * Set the log level for a given type.
>    *
> + * @param pattern
> + *   The regexp identifying the log type.
> + * @param level
> + *   The level to be set.
> + * @return
> + *   0 on success, a negative value if level is invalid.
> + */
> +int rte_log_set_level_regexp(const char *pattern, uint32_t level);
> +
> +/**
> + * Set the log level for a given type.
> + *
>    * @param logtype
>    *   The log type identifier.
>    * @param level
> diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> index ef48500e9..f70b4b937 100644
> --- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> +++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> @@ -193,5 +193,6 @@ DPDK_17.05 {
>   	rte_log_dump;
>   	rte_log_register;
>   	rte_log_set_level;
> +	rte_log_set_level_regexp;
>   
>   } DPDK_17.02;