On Sun, 2012-11-18 at 11:47 +0200, Vladimir Kondratiev wrote:

I see 2 drivers that use dynamic prefix:

- mentioned above drivers/tty/ipwireless/hardware.c
- drivers/isdn/hardware/mISDN/

I see several options:

1) require prefix_str to be constant. Patch code mentioned. For example,
code above may reads:

static void dump_data_bytes(const char *type, const unsigned char *data,
			    unsigned length)
{
	pr_debug(IPWIRELESS_PCCARD_NAME ": %s %s\n",
			type, data_type(data, length));
	print_hex_dump_bytes(IPWIRELESS_PCCARD_NAME, 0, (void *)data,
			length < DUMP_MAX_BYTES ? length : DUMP_MAX_BYTES);
}

2) introduce fixed format string in DEFINE_DYNAMIC_DEBUG_METADATA, like

DEFINE_DYNAMIC_DEBUG_METADATA((descriptor, "hexdump");

3) remove print_hex_dump_bytes from this patch

I think 1) is the best, opinions?

Another option could be testing __builtin_constant_p(prefix)