Re: [PATCH] perf probe: convert_name_to_addr() allocated the wrongsize buffers for names

[Masami Hiramatsu]

(2012/10/17 17:28), Hyeoncheol Lee wrote:
> The function allocated wrong size buffers for names
> 
> Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
> Cc: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Hyeoncheol Lee <hyc.lee@xxxxxxxxx>
> ---
>  tools/perf/util/probe-event.c |   11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index 49a256e..5cd7c42 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -2273,6 +2273,8 @@ int show_available_funcs(const char *target, struct strfilter *_filter,
>  	return available_user_funcs(target);
>  }
>  

Please add a comment like below on the code.

/*
 * sizeof(type) * 2 returns the maximum length of hexadecimal number
 * of type, because each half byte is encoding in one hex character.
 * Another 3 bytes are for "0x" and null character.
 */

Others are OK for me :)

Thanks!

> +#define MAX_ADDRNAME_LEN  (3 + sizeof(unsigned long long) * 2)
> +
>  /*
>   * uprobe_events only accepts address:
>   * Convert function and any offset to address
> @@ -2332,7 +2334,7 @@ static int convert_name_to_addr(struct perf_probe_event *pev, const char *exec)
>  	if (!pev->group) {
>  		char *ptr1, *ptr2, *exec_copy;
>  
> -		pev->group = zalloc(sizeof(char *) * 64);
> +		pev->group = zalloc(sizeof(char) * 64);
>  		exec_copy = strdup(exec);
>  		if (!exec_copy) {
>  			ret = -ENOMEM;
> @@ -2352,14 +2354,15 @@ static int convert_name_to_addr(struct perf_probe_event *pev, const char *exec)
>  		free(exec_copy);
>  	}
>  	free(pp->function);
> -	pp->function = zalloc(sizeof(char *) * MAX_PROBE_ARGS);
> +	pp->function = zalloc(sizeof(char) * MAX_ADDRNAME_LEN);
>  	if (!pp->function) {
>  		ret = -ENOMEM;
>  		pr_warning("Failed to allocate memory by zalloc.\n");
>  		goto out;
>  	}
> -	e_snprintf(pp->function, MAX_PROBE_ARGS, "0x%llx", vaddr);
> -	ret = 0;
> +	ret = e_snprintf(pp->function, MAX_ADDRNAME_LEN, "0x%llx", vaddr);
> +	if (ret > 0)
> +		ret = 0;
>  
>  out:
>  	if (map) {
> 


-- 
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx


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