RE: [Fault-injection-developer] LKML threads about kprobes

[Lynch, R. <rus...@in...>]

What about using the debug registers via the kwatch functions?  Does =
that
solve our MMIO needs?

	-rusty

-----Original Message-----
From: Wang, Stanley=20
Sent: Thursday, November 07, 2002 7:08 PM
To: Wang, Frank; Zhuang, Louis; Lynch, Rusty;
'fau...@so...'
Subject: RE: [Fault-injection-developer] LKML threads about kprobes


Kprobes can only capture a specific instruction (by specified =
instruction's
address).
It cannot capture all accesses to a specific MMIO address :)
-----Original Message-----
From: Wang, Frank [mailto:fra...@in...]
Sent: 2002=C4=EA11=D4=C28=C8=D5 10:58
To: Zhuang, Louis; Lynch, Rusty; =
'fau...@so...'
Subject: RE: [Fault-injection-developer] LKML threads about kprobes


"With kprobes you can register to have a handler called before a =
specific
address is executed", is this correct?
The idea of capturing pagefault exception is to capture an MMIO address
access. If the above sentence is correct, why we continue to capture
pagefault exception?
Or kprobes enables you capture a specific address access but it must be =
with
interrupt-enabled? Why is it? Can we change the kprobe to enable this =
in
interrupt-disabled condition?
-----Original Message-----
From: Zhuang, Louis [mailto:lou...@in...]
Sent: 2002=C4=EA11=D4=C28=C8=D5 9:31
To: Lynch, Rusty; 'fau...@so...'
Subject: RE: [Fault-injection-developer] LKML threads about kprobes


Yes, It is not enough. FITH needs capture pagefault exception in
interrept-disabled condition, just as kprobes for do_int3/do_debug.=20
-----Original Message-----
From: Lynch, Rusty=20
Sent: Friday, November 08, 2002 9:02 AM
To: Zhuang, Louis; Lynch, Rusty; =
'fau...@so...'
Subject: RE: [Fault-injection-developer] LKML threads about kprobes


Ok, now I'm confused.  With kprobes you can register to have a handler
called before a specific address is executed.  Why is that not enough?

    -rusty
-----Original Message-----
From: Zhuang, Louis=20
Sent: Thursday, November 07, 2002 4:48 PM
To: Lynch, Rusty; 'fau...@so...'
Subject: RE: [Fault-injection-developer] LKML threads about kprobes


Hi, Rusty
    We did work based on kprobes. After we investigated kprobes, we =
found
kprobes had removed GKHI support. So we need to find another way to get
additional control in exception handling... This is a problem we need =
to
solve in 2.5.x
-----Original Message-----
From: Lynch, Rusty=20
Sent: Friday, November 08, 2002 1:30 AM
To: Zhuang, Louis; 'fau...@so...'
Subject: RE: [Fault-injection-developer] LKML threads about kprobes


It looks to me like kprobes will make it in the kernel.  Why don't we =
work
under that assumption for now.

    -rusty
-----Original Message-----
From: Zhuang, Louis [mailto:lou...@in...]
Sent: Thursday, November 07, 2002 12:27 AM
To: 'fau...@so...'
Subject: RE: [Fault-injection-developer] LKML threads about kprobes


Humm... kprobes in 2.5.x removed GKHI(General Kernel Hook Interface)
mechanism, which FITH needed. But all kprobes patch in 2.5.x is useful =
for
FITH, such as do_int3/do_debug interrupt gate. We need a mederate patch =
to
hook these exception for FITH. But I wonder if this can be accepted by =
LKML.
Any comments
    -Louis