RE: [Fault-injection-developer] LKML threads about kprobes
Status: Alpha
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rustyl
From: Zhuang, L. <lou...@in...> - 2002-11-08 03:26:33
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Still no. :-) Debug Register can only capture the data access *AFTER* access has completed. It is a hardware restriction in IA32. -----Original Message----- From: Lynch, Rusty Sent: Friday, November 08, 2002 11:14 AM To: Wang, Stanley; Wang, Frank; Zhuang, Louis; Lynch, Rusty; 'fau...@so...' Subject: RE: [Fault-injection-developer] LKML threads about kprobes What about using the debug registers via the kwatch functions? Does that solve our MMIO needs? -rusty -----Original Message----- From: Wang, Stanley 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?11?8? 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?11?8? 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. -----Original Message----- From: Lynch, Rusty 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 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 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 |