Re: [PATCH] printk-formats.txt documentation update

[Tim Bird <tim.bird@am.sony.com>]

On 02/05/2011 04:15 PM, Andrew Murray wrote:
> From: Andrew Murray <amurray@mpc-data.co.uk>
> 
> This patch updates the incomplete documentation concerning the printk
> extended format specifiers.
> 
> Signed-off-by: Andrew Murray <amurray@mpc-data.co.uk>
> ---
> diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
> index 1b5a5dd..df14336 100644
> --- a/Documentation/printk-formats.txt
> +++ b/Documentation/printk-formats.txt
> @@ -9,7 +9,42 @@ If variable is of Type,		use printk format specifier:
>  		size_t			%zu or %zx
>  		ssize_t			%zd or %zx
> 
> -Raw pointer value SHOULD be printed with %p.
> +Raw pointer value SHOULD be printed with %p. The kernel supports
> +the following extended format specifiers for pointer types:
> +
> +	General:
> +
> +	%pF	function pointer with offset, e.g. module_start
> +	%pf	function pointer without offset, e.g. module_start+0x0/0x62 [hello]
> +	%pS	text symbol with offset	
> +	%ps	text symbol without offset
> +	%pR	struct resource with decoded flags, e.g. [mem 0x0-0x1f 64 bit pref]
> +	%pr	struct resource with raw flags, e.g. [mem 0x0-0x1f flags 0x201]
> +
> +	MAC/FDDI addresses:
> +	
> +	%pM	colon-seperated 6-byte MAC address in hex notation, e.g. 00:01:02:03:04:05
> +	%pm	non-colon-seperated 6-byte MAC address is hex notation, e.g. 000102030405
> +	%pMF	6-byte dash-separated FDDI hex notation
> +
> +	IPv4 addresses:
> +
> +	%pI4	IPv4 dot-seperated decimal without leading 0's, e.g. 1.2.3.4
> +	%pi4	IPv4 dot-seperated decimal with leading 0's, 001.002.003.004
> +	%p[Ii]4[hl] IPv4 dot-seperated decimal with/without leading 0's for
> +		host (h), little (l) or network/big (default) endian order
> +
> +	IPv6 addresses:
> +	%pI6	IPv6 colon-seperated network-order 16 bit hex with leading 0's,
> +		e.g. 0001:0203:...:0708
> +	%pi6	IPv6 non-colon-seperated network-order 16 bit hex with leading 0's,
> +		e.g. 000102...0f
> +	%pI6c	IPv6 address as described by
> +		http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00,
> +		e.g. 1::708
> +
> +	%pU[bBlL] 16 byte UUID/GUID in big or little endian using lower or upper case
> +
> 
>  u64 SHOULD be printed with %llu/%llx, (unsigned long long):

I like this, as it has information that is not documented elsewhere.

Some feedback on the patch:

Some of these lines are longer than 80 chars.  Can you please truncate
things to fit in an 80-column terminal window?

Thanks,
 -- Tim

=============================
Tim Bird
Architecture Group Chair, CE Linux Forum
Senior Staff Engineer, Sony Network Entertainment
=============================