[U-Boot] [PATCH] cmd_fdt.c: Use %p when printing pointers

[Wolfgang Denk]

Dear Tom Rini,

In message <1351558398-6902-1-git-send-email-trini at ti.com> you wrote:
> When putting pointers into a format string use %p to ensure that they
> are printed correctly regardless of bitsize.  This fixes warnings on
> sandbox on 64bit systems.
> 
> Cc: Joe Hershberger <joe.hershberger at ni.com>
> Cc: Gerald Van Baren <vanbaren at cideas.com>
> Signed-off-by: Tom Rini <trini at ti.com>
> ---
>  common/cmd_fdt.c |    6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/common/cmd_fdt.c b/common/cmd_fdt.c
> index a5e2cfc..f9acfc1 100644
> --- a/common/cmd_fdt.c
> +++ b/common/cmd_fdt.c
> @@ -375,7 +375,7 @@ int do_fdt (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
>  					/* Get address */
>  					char buf[11];
>  
> -					sprintf(buf, "0x%08X", (uint32_t)nodep);
> +					sprintf(buf, "0x%p", nodep);
>  					setenv(var, buf);

This may put bogus data ("var=0x(null)") into the environment.

I see two approaches to fix this:

1) Handle this locally, say like that:

	char buf[11] = { '0', 0, };

	if (nodep)
		sprintf(buf, "0x%p", nodep);
	
	setenv(var, buf);

   This is the solution with minimal global impact.

2) Fix the root cause: given that we have valid situations where we
   may want to dereference a pointer pointing to address 0x0000, 
   I wonder if it would not actually be better (i. e. more correct) to
   get rid of the

   	495 static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
	496                 int field_width, int precision, int flags)
	497 {
	498         if (!ptr)
	499                 return string(buf, end, "(null)", field_width, precision,
	500                               flags);

   special handling in "lib/vsprintf.c"

   Would anybody shed any tears if we drop this?

Best regards,

Wolfgang Denk

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