Re: [PATCH v2 01/17] tracing: probeevent: Fix to support minus offset from symbol

[Masami Hiramatsu]

Hi Steve,

Could you pick this separately since this is a bugfix?

Thank you,

On Wed, 21 Feb 2018 23:54:37 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> In Documentation/trace/kprobetrace.txt, it says
> 
>  @SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)
> 
> However, the parser doesn't parse minus offset correctly.
> This fixes the parser to get minus offset correctly.
> 
> Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> ---
>  kernel/trace/trace_kprobe.c |    2 +-
>  kernel/trace/trace_probe.c  |   10 +++++-----
>  kernel/trace/trace_probe.h  |    2 +-
>  3 files changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 5ce9b8cf7be3..dab4a5b54269 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -754,7 +754,7 @@ static int create_trace_kprobe(int argc, char **argv)
>  		/* a symbol specified */
>  		symbol = argv[1];
>  		/* TODO: support .init module functions */
> -		ret = traceprobe_split_symbol_offset(symbol, &offset);
> +		ret = traceprobe_split_symbol_offset(symbol, (long *)&offset);
>  		if (ret) {
>  			pr_info("Failed to parse either an address or a symbol.\n");
>  			return ret;
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index d59357308677..3e291a754862 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -320,7 +320,7 @@ static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
>  }
>  
>  /* Split symbol and offset. */
> -int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)
> +int traceprobe_split_symbol_offset(char *symbol, long *offset)
>  {
>  	char *tmp;
>  	int ret;
> @@ -328,13 +328,13 @@ int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)
>  	if (!offset)
>  		return -EINVAL;
>  
> -	tmp = strchr(symbol, '+');
> +	tmp = strpbrk(symbol, "+-");
>  	if (tmp) {
> -		/* skip sign because kstrtoul doesn't accept '+' */
> -		ret = kstrtoul(tmp + 1, 0, offset);
> +		ret = kstrtoul(tmp + 1, 0, (unsigned long *)offset);
>  		if (ret)
>  			return ret;
> -
> +		if (*tmp == '-')
> +			*offset = -(*offset);
>  		*tmp = '\0';
>  	} else
>  		*offset = 0;
> diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
> index 0745f895f780..75daff22ccea 100644
> --- a/kernel/trace/trace_probe.h
> +++ b/kernel/trace/trace_probe.h
> @@ -365,7 +365,7 @@ extern int traceprobe_conflict_field_name(const char *name,
>  extern void traceprobe_update_arg(struct probe_arg *arg);
>  extern void traceprobe_free_probe_arg(struct probe_arg *arg);
>  
> -extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);
> +extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
>  
>  /* Sum up total data length for dynamic arraies (strings) */
>  static nokprobe_inline int
> 


-- 
Masami Hiramatsu <mhiramat@xxxxxxxxxx>