Messages in this thread |  | | Date | Sun, 13 Aug 2006 18:41:59 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] lockdep: disable lock debugging when kernel state becomes untrusted |
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On Mon, 14 Aug 2006 03:09:54 +0200 Voluspa <lista1@comhem.se> wrote:
> On 2006-07-10 21:02:59 git-commits-head received: > > commit 2c16e9c888985761511bd1905b00fb271169c3c0 > > tree e17756b3ed27b0f4953547c39cf46864cdd6f818 > > parent e54695a59c278b9ff48cd4b263da7a1d392f5061 > > author Arjan van de Ven Mon, 10 Jul 2006 > > 18:45:42 -0700 committer Linus Torvalds Tue, 11 > > Jul 2006 03:24:27 -0700 > > > > [PATCH] lockdep: disable lock debugging when kernel state becomes > > untrusted > > > > Disable lockdep debugging in two situations where the integrity of the > > kernel no longer is guaranteed: when oopsing and when hitting a > > tainting-condition. The goal is to not get weird lockdep traces that > > don't make sense or are otherwise undebuggable, to not waste time. > > > > Lockdep assumes that the previous state it knows about is valid to > > operate, which is why lockdep turns itself off after the first > > violation it reports, after that point it can no longer make that > > assumption. > > > > A kernel oops means that the integrity of the kernel compromised; in > > addition anything lockdep would report is of lesser importance than the > > oops. > > > > All the tainting conditions are of similar integrity-violating nature > > and also make debugging/diagnosing more difficult. > > On my x86_64 notebook I need ndiswrapper. No but-s, if-s or anything-s. > Period. I also have to work outside of X in a clean terminal (console). > > This patch unfortunately creates a 'pipe' directly from > /var/log/messages to the screen. So if I work in a textbased program, > and something happens in the log, the program gets a broken interface. > Programs that simultaniously output to the log becomes unusable. > > It is also darn irritating when text strings materializes at the shell > prompt... > > Once the 'pipe' is established (by tainting) it can not be reverted by > eg rmmod ndiswrapper. > > I haven't even enabled any lockdep debugging:
That would appear to be a bug. debug_locks_off() is running console_verbose() waaaay after the locking selftest code has completed.
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