Re: [PATCH 2/3] tools lib traceevent: fix pointer-integer size mismatch

[Arnaldo Carvalho de Melo <acme@ghostprotocols.net>]

Em Wed, Jan 15, 2014 at 10:44:07AM +0000, Mark Rutland escreveu:
> The scsi and cfg80211 plugins cast between unsigned long long and
> pointers, which is problematic for architectures where unsigned long
> long is wider than the native pointer size:
> 
>   linux/tools/lib/traceevent/plugin_scsi.c: In function ‘process_scsi_trace_parse_cdb’:
>   linux/tools/lib/traceevent/plugin_scsi.c:408:26: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
>     scsi_trace_parse_cdb(s, (unsigned char *) args[1], args[2]);
> 
>   linux/tools/lib/traceevent/plugin_cfg80211.c: In function ‘process___le16_to_cpup’:
>   linux/tools/lib/traceevent/plugin_cfg80211.c:11:18: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
>     uint16_t *val = (uint16_t *) args[0];
> 
> This patch adds an intermediate cast to unsigned long, silencing the
> warning.

Steven, Jiri: Acked-by?
 
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Cc: Jiri Olsa <jolsa@redhat.com>
> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
> Cc: Ingo Molnar <mingo@redhat.com>
> ---
>  tools/lib/traceevent/plugin_cfg80211.c | 2 +-
>  tools/lib/traceevent/plugin_scsi.c     | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> I'm not sure about this one as I'm not certain I read all the sites
> input values for args could be generated. I'd appreciate if someone more
> familiar with traceevent plugins could verify this makes sense.
> 
> Mark.
> 
> diff --git a/tools/lib/traceevent/plugin_cfg80211.c b/tools/lib/traceevent/plugin_cfg80211.c
> index dcab8e8..57e9822 100644
> --- a/tools/lib/traceevent/plugin_cfg80211.c
> +++ b/tools/lib/traceevent/plugin_cfg80211.c
> @@ -8,7 +8,7 @@ static unsigned long long
>  process___le16_to_cpup(struct trace_seq *s,
>  		       unsigned long long *args)
>  {
> -	uint16_t *val = (uint16_t *) args[0];
> +	uint16_t *val = (uint16_t *) (unsigned long) args[0];
>  	return val ? (long long) le16toh(*val) : 0;
>  }
>  
> diff --git a/tools/lib/traceevent/plugin_scsi.c b/tools/lib/traceevent/plugin_scsi.c
> index 6fb8e3e..7ef16cc 100644
> --- a/tools/lib/traceevent/plugin_scsi.c
> +++ b/tools/lib/traceevent/plugin_scsi.c
> @@ -405,7 +405,7 @@ scsi_trace_parse_cdb(struct trace_seq *p, unsigned char *cdb, int len)
>  unsigned long long process_scsi_trace_parse_cdb(struct trace_seq *s,
>  						unsigned long long *args)
>  {
> -	scsi_trace_parse_cdb(s, (unsigned char *) args[1], args[2]);
> +	scsi_trace_parse_cdb(s, (unsigned char *) (unsigned long) args[1], args[2]);
>  	return 0;
>  }
>  
> -- 
> 1.8.1.1