[ofa-general] Re: [PATCH] osm: source and destination strings overlap when using sprintf()

[Michael S. Tsirkin]

> Quoting Yevgeny Kliteynik <kliteyn at dev.mellanox.co.il>:
> Subject: [PATCH] osm: source and destination strings overlap when using sprintf()
> 
> Hi Hal,
> 
> Fixing a problematic usage of sprintf() in osm_helper.c:
> 
> When using sprintf(), source and destination strings should
> not overlap, otherwise the function behavior is undefined.
> 
> Please apply to ofed_1_2 and to master.
> 
> Thanks.
> 
> -- Yevgeny
> 
> Signed-off-by: Yevgeny Kliteynik <kliteyn at dev.mellanox.co.il>
> ---
> osm/opensm/osm_helper.c |   47 
> ++++++++++++++++++++++++++++++++++-------------
> 1 files changed, 34 insertions(+), 13 deletions(-)

.... skip ...
	
>     for (i = 0; i < 32; i++)
> -      sprintf( buf_line2,"%s 0x%01X |",
> -               buf_line2, p_vla_tbl->vl_entry[i].weight);
> +    {
> +      sprintf( tmp_buf_line," 0x%01X |",
> +               p_vla_tbl->vl_entry[i].weight);
> +      strcat( buf_line2, tmp_buf_line );
> +    }
>     osm_log( p_log, log_level,
>              "VlArb dump:\n"
>              "\t\t\tport_guid...........0x%016" PRIx64 "\n"

These tmp-bufs are quite ugly, and bloat the code up.
Since you seem to do a strcat which does an anyway, how about, for example:

-      sprintf( buf_line1,"%s 0x%01x |",
-               buf_line1, p_vla_tbl->vl_entry[i].vl);
+      sprintf( buf_line1 + strlen(buf_line1)," 0x%01x |",
+               p_vla_tbl->vl_entry[i].vl);

and so on in all the other places?

-- 
MST