Re: [PATCH] printk: Let %pR handle NULL pointers

From: Valdis . Kletnieks
Date: Sun Jan 04 2009 - 00:14:58 EST


On Sat, 03 Jan 2009 21:02:15 PST, Trent Piepho said:
> resource pointer. Maybe "[]" or "[-]" would be better? A null MAC address
> could be ":::::" or "x:x:x:x:x:x". "N.U.L.L" or "x.x.x.x" for a null IP4
> address. And so on. So the printout looks nicer when a NULL pointer isn't
> a bug.

Have to be careful for IPv6 addresses - '::' is a legal representation of
an all-zeros address. Also, N.U.L.L. may give indigestion to logfile parsers
that are expecting a numeric value in the IP address. It's however unclear
whether we should pick something that doesn't have 3 periods in it, so it
can't match, or whether *that* will give regexp-based logfile readers
indigestion when they don't pick up an IP address where they expected...

Do we want the %pI6 format to do the multiple-zeros -> :: compression?

(Adding netdev to cc: list)

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