Re: [1/2] 2.6.22-rc5: known regressions with patches

[Dave Jones <davej@redhat.com>]

On Wed, Jun 20, 2007 at 04:15:53PM -0700, Arjan van de Ven wrote:
 > On Wed, 2007-06-20 at 19:07 -0400, Dave Jones wrote:
 > > On Wed, Jun 20, 2007 at 03:38:06PM -0700, Linus Torvalds wrote:
 > > 
 > >  > And yes, that patch already got merged. However, the patch to *allow* 
 > >  > Kprobes with DEBUG_RODATA is not, and will not be. It's not a regression, 
 > >  > and quite frankly, I don't think I would even want that patch.
 > >  > 
 > >  > Kprobes fundamntally disagrees with DEBUG_RODATA, there's no point in 
 > >  > "working around it". Better just admit it.
 > > 
 > > Surely the fundamental disagreement is only due to DEBUG_RODATA
 > > covering write-protection of both .text, and .rodata  ?
 > > I can see value in having a kernel that supports kprobes, whilst
 > > at the same point, raising red flags if something writes into
 > > a const string. With my distro kernel maintainer hat on, I always
 > > hate these 'pick one' decisions, because I always get convincing
 > > arguments from proponents of both sides.
 > > 
 > > Was it always this way?  I thought DEBUG_RODATA initially just
 > > covered, well.. rodata.    And kprobes only wants to change .text
 > > doesn't it ?
 > 
 > no this got "fixed" recently. It used to only cover data.
 > Andi merged a patch to make it cover text too.. imo we should reverse
 > that, or make the check better and not have it cover text if kprobes is
 > active. I can do the later if people are ok with that, it's
 > approximately 3 lines of code.

Having the text as a separate option makes sense to me.
(Or at the least we should rename DEBUG_RODATA, as it's now misleading).

	Dave

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