* How to crash a system and take a dump?
@ 2002-02-04 11:26 sathish jayapalan
2002-02-04 12:31 ` Gianni Tedesco
2002-02-04 13:32 ` Suparna Bhattacharya
0 siblings, 2 replies; 6+ messages in thread
From: sathish jayapalan @ 2002-02-04 11:26 UTC (permalink / raw)
To: linux-kernel; +Cc: sathish_jayapalan
Hi,
I have a doubt. I know that linux kernel doesn't crash
so easily. Is there any way to panic the system? Can I
go to the source area and insert/modify a variable in
kernel code so that the kernel references a null
pointer and crashes while running the kernel compiled
with this variable. My aim is to learn crash dump
analysis with 'Lcrash tool". Please help me out with
this.
Thanks in advance,
sathish
__________________________________________________
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^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: How to crash a system and take a dump?
@ 2002-02-04 11:40 Alexander Sandler
2002-02-05 2:32 ` Philippe Troin
0 siblings, 1 reply; 6+ messages in thread
From: Alexander Sandler @ 2002-02-04 11:40 UTC (permalink / raw)
To: 'sathish jayapalan', linux-kernel
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> Hi,
> I have a doubt. I know that linux kernel doesn't crash
> so easily. Is there any way to panic the system? Can I
> go to the source area and insert/modify a variable in
> kernel code so that the kernel references a null
> pointer and crashes while running the kernel compiled
> with this variable. My aim is to learn crash dump
> analysis with 'Lcrash tool". Please help me out with
> this.
Go to interrupt handler (for instance in fs/buffer.c end_buffer_io_async() )
and cause segmentation fault.
System will try to kill process that caused segmentation fault and since
it's in interrupt context will panic.
Sasha.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: How to crash a system and take a dump?
2002-02-04 11:26 sathish jayapalan
@ 2002-02-04 12:31 ` Gianni Tedesco
2002-02-04 13:32 ` Suparna Bhattacharya
1 sibling, 0 replies; 6+ messages in thread
From: Gianni Tedesco @ 2002-02-04 12:31 UTC (permalink / raw)
To: sathish jayapalan; +Cc: linux-kernel
On Mon, 2002-02-04 at 11:26, sathish jayapalan wrote:
> Hi,
> I have a doubt. I know that linux kernel doesn't crash
> so easily. Is there any way to panic the system? Can I
> go to the source area and insert/modify a variable in
> kernel code so that the kernel references a null
> pointer and crashes while running the kernel compiled
> with this variable. My aim is to learn crash dump
> analysis with 'Lcrash tool". Please help me out with
> this.
Im not sure about the Lcrash tool, but core dumps can be obtained from
the kernel at any time simply by reading /proc/kcore.
Hope that helps.
--
// Gianni Tedesco <gianni@ecsc.co.uk>
80% of all email is a figment of procmails imagination.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: How to crash a system and take a dump?
2002-02-04 11:26 sathish jayapalan
2002-02-04 12:31 ` Gianni Tedesco
@ 2002-02-04 13:32 ` Suparna Bhattacharya
1 sibling, 0 replies; 6+ messages in thread
From: Suparna Bhattacharya @ 2002-02-04 13:32 UTC (permalink / raw)
To: sathish jayapalan; +Cc: linux-kernel
With LKCD, you can also trigger a dump via the Alt+Sysrq+c key.
If you run into problems when trying to use this, then you might need
some of the fixes that we've checked into the lkcd cvs tree.
Regards
Suparna
IBM Linux Technology Center
sathish jayapalan wrote:
>
> Hi,
> I have a doubt. I know that linux kernel doesn't crash
> so easily. Is there any way to panic the system? Can I
> go to the source area and insert/modify a variable in
> kernel code so that the kernel references a null
> pointer and crashes while running the kernel compiled
> with this variable. My aim is to learn crash dump
> analysis with 'Lcrash tool". Please help me out with
> this.
>
> Thanks in advance,
> sathish
>
> __________________________________________________
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> http://auctions.yahoo.com
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: How to crash a system and take a dump?
2002-02-04 11:40 How to crash a system and take a dump? Alexander Sandler
@ 2002-02-05 2:32 ` Philippe Troin
0 siblings, 0 replies; 6+ messages in thread
From: Philippe Troin @ 2002-02-05 2:32 UTC (permalink / raw)
To: Alexander Sandler; +Cc: 'sathish jayapalan', linux-kernel
Alexander Sandler <ASandler@store-age.com> writes:
> > Hi,
> > I have a doubt. I know that linux kernel doesn't crash
> > so easily. Is there any way to panic the system? Can I
> > go to the source area and insert/modify a variable in
> > kernel code so that the kernel references a null
> > pointer and crashes while running the kernel compiled
> > with this variable. My aim is to learn crash dump
> > analysis with 'Lcrash tool". Please help me out with
> > this.
>
> Go to interrupt handler (for instance in fs/buffer.c end_buffer_io_async() )
> and cause segmentation fault.
> System will try to kill process that caused segmentation fault and since
> it's in interrupt context will panic.
Simplier: insmod this module:
#include <linux/module.h>
int init_module()
{
panic("Forcing panic");
}
int cleanup_module()
{
}
Phil.
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: How to crash a system and take a dump?
@ 2002-02-05 18:50 Alexander Sandler
0 siblings, 0 replies; 6+ messages in thread
From: Alexander Sandler @ 2002-02-05 18:50 UTC (permalink / raw)
To: 'Philippe Troin'; +Cc: Linux Kernel Mailing List (E-mail)
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This one is too genious to be found right away ;)
> Simplier: insmod this module:
>
> #include <linux/module.h>
>
> int init_module()
> {
> panic("Forcing panic");
> }
>
> int cleanup_module()
> {
> }
Sasha.
^ permalink raw reply [flat|nested] 6+ messages in thread
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2002-02-04 11:40 How to crash a system and take a dump? Alexander Sandler
2002-02-05 2:32 ` Philippe Troin
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2002-02-04 11:26 sathish jayapalan
2002-02-04 12:31 ` Gianni Tedesco
2002-02-04 13:32 ` Suparna Bhattacharya
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