[Crash-utility] [PATCH] symbol: fix offset print for function pointers that return pointers

[HAGIO KAZUHITO(萩尾 一仁)]

-----Original Message-----
> In the show_member_offset() function, when trying to handle function
> pointers, the case for "(*" is handled.  However, if the function
> pointer returns a pointer or a pointer to a pointer, then the
> condition is unhandled.  This results in the offset not being printed.
> 
> Fix by first checking if the member is potentially a function pointer,
> then checking if it returns a pointer or a pointer to a pointer.
> 
> Signed-off-by: John Pittman <jpittman at redhat.com>

Good catch... I've confirmed that the patch works as expected with RHEL7's
struct offload_callbacks:

crash> struct -o offload_callbacks
struct offload_callbacks {
   [0] struct sk_buff *(*gso_segment)(struct sk_buff *, netdev_features_t);
   [8] struct sk_buff **(*gro_receive)(struct sk_buff **, struct sk_buff *);
  [16] int (*gro_complete)(struct sk_buff *, int);
}
SIZE: 24

Acked-by: Kazuhito Hagio <k-hagio-ab at nec.com>

Thanks,
Kazu

> ---
>  symbols.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/symbols.c b/symbols.c
> index a2d5c6c..5d7da6e 100644
> --- a/symbols.c
> +++ b/symbols.c
> @@ -8356,8 +8356,15 @@ show_member_offset(FILE *ofp, struct datatype_member *dm, char *inbuf)
>  		}
>  	} else if (c) {
>  		for (i = 0; i < c; i++) {
> -			if (STRNEQ(arglist[i], "(*")) {
> -				target = arglist[i]+2;
> +			if (strstr(inbuf, "(*")) {
> +				if (STRNEQ(arglist[i], "(*"))
> +					target = arglist[i]+2;
> +				else if (STRNEQ(arglist[i], "*(*"))
> +					target = arglist[i]+3;
> +				else if (STRNEQ(arglist[i], "**(*"))
> +					target = arglist[i]+4;
> +				else
> +					continue;
>  				if (!(t1 = strstr(target, ")")))
>  					continue;
>  				*t1 = NULLCHAR;
> --
> 2.17.2