* Re: [PATCH] MODSIGN: Add TAINT_NOKEY_MODULE [not found] ` <8738xvxv55.fsf@rustcorp.com.au> @ 2013-01-21 0:19 ` Frank Ch. Eigler 2013-01-21 1:50 ` Rusty Russell 2013-01-21 0:46 ` Rafael J. Wysocki 1 sibling, 1 reply; 3+ messages in thread From: Frank Ch. Eigler @ 2013-01-21 0:19 UTC (permalink / raw) To: Rusty Russell Cc: Dave Jones, Josh Boyer, dhowells, linux-kernel, peterz, mingo, Len Brown, Rafael J. Wysocki, linux-acpi Hi - > [...] > - add_taint(TAINT_DIE); > + add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); > [...] If "UNRELIABLE" a good way to describe it - not DANGEROUS or COUNTERPRODUCTIVE or something, then maybe lockdep *can* produce reasonable results following such a taint. If the results are merely suspect, could lockdep reports include the taint report, but otherwise keep working? - FChE ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] MODSIGN: Add TAINT_NOKEY_MODULE 2013-01-21 0:19 ` [PATCH] MODSIGN: Add TAINT_NOKEY_MODULE Frank Ch. Eigler @ 2013-01-21 1:50 ` Rusty Russell 0 siblings, 0 replies; 3+ messages in thread From: Rusty Russell @ 2013-01-21 1:50 UTC (permalink / raw) To: Frank Ch. Eigler Cc: Dave Jones, Josh Boyer, dhowells, linux-kernel, peterz, mingo, Len Brown, Rafael J. Wysocki, linux-acpi "Frank Ch. Eigler" <fche@redhat.com> writes: > Hi - > >> [...] >> - add_taint(TAINT_DIE); >> + add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); >> [...] > > If "UNRELIABLE" a good way to describe it - not DANGEROUS or > COUNTERPRODUCTIVE or something, then maybe lockdep *can* produce > reasonable results following such a taint. If the results are merely > suspect, could lockdep reports include the taint report, but otherwise > keep working? git blame is your friend here: commit 2c16e9c888985761511bd1905b00fb271169c3c0 Author: Arjan van de Ven <arjan@linux.intel.com> Date: Mon Jul 10 04:45:42 2006 -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. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> Cheers, Rusty. ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] MODSIGN: Add TAINT_NOKEY_MODULE [not found] ` <8738xvxv55.fsf@rustcorp.com.au> 2013-01-21 0:19 ` [PATCH] MODSIGN: Add TAINT_NOKEY_MODULE Frank Ch. Eigler @ 2013-01-21 0:46 ` Rafael J. Wysocki 1 sibling, 0 replies; 3+ messages in thread From: Rafael J. Wysocki @ 2013-01-21 0:46 UTC (permalink / raw) To: Rusty Russell Cc: Dave Jones, Josh Boyer, Frank Ch. Eigler, dhowells, linux-kernel, peterz, mingo, Len Brown, linux-acpi On Monday, January 21, 2013 10:30:22 AM Rusty Russell wrote: > Dave Jones <davej@redhat.com> writes: > > On Thu, Jan 17, 2013 at 11:27:27AM +1030, Rusty Russell wrote: > > > > > taint: add explicit flag to show whether lock dep is still OK. > > > > > > Fix up all callers as they were before, with make one change: an > > > unsigned module taints the kernel, but doesn't turn off lockdep. > > > > > > Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> > > > > This made my brain itch a little until I got to the bottom of the > > patch and saw the new definition of add_taint. Perhaps instead of > > false/true, we have LOCKDEP_LIVES/LOCKDEP_DIES or similar defines > > to make it clearer what's actually happening without having to > > go read the function ? > > The reason I didn't do that is because it's theoretically more than > lockdep: it's anything which relies on kernel integrity. > > Then I got the true/false thing mixed up myself, so I think you're right > :) > > BTW, ACPI people: those TAINT_OVERRIDDEN_ACPI_TABLE taints were > disabling lockdep: is that overzealous? I think so, although it's quite difficult to say what the intention was at this point. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2013-01-21 1:53 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <20130104191205.GD27554@hansolo.jdub.homelinux.org>
[not found] ` <87bod14x44.fsf@rustcorp.com.au>
[not found] ` <20130107145832.GA12363@hansolo.jdub.homelinux.org>
[not found] ` <20130115190911.GA6964@hansolo.jdub.homelinux.org>
[not found] ` <87y5ftyf51.fsf@rustcorp.com.au>
[not found] ` <20130116193724.GF6964@hansolo.jdub.homelinux.org>
[not found] ` <87pq14y6bs.fsf@rustcorp.com.au>
[not found] ` <20130117150202.GB32586@redhat.com>
[not found] ` <8738xvxv55.fsf@rustcorp.com.au>
2013-01-21 0:19 ` [PATCH] MODSIGN: Add TAINT_NOKEY_MODULE Frank Ch. Eigler
2013-01-21 1:50 ` Rusty Russell
2013-01-21 0:46 ` Rafael J. Wysocki
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox