4:03 p.m.
Hello all,
I'm trying to get myself ramped to using crash on x86_64.
In x86_64 there is no register stack and function arguments aren't
typically placed on the stack, therefore we aren't able to see the
function arguments in the bt -f output.
Is there a trick to dumping out %rdi, %rsi, %rdx, etc?
I hope this isn't too lame of a question. I'm just getting my toes wet
with x86_64 and kdump/crash.
Thanks in advance,
Paul Sanders
SGI Global Product Support
9:02 p.m.
Well, the BIG problem (if there is a BIG problem) is not so much dumping
the registers as it is the fact that the registers may or may not be
"spilled" in subsequent functions.
Sometimes the args are copied to the stack, sometimes they are spilled
in the very next routine, some times they are not spilled at all.
Welcome to the world of "hard luck stack analysis".
Sorry I cannot provide a "simple" answer.
- jim
On Tue, 2008-09-02 at 14:03 -0700, Paul Sanders wrote:
Hello all,
I'm trying to get myself ramped to using crash on x86_64.
In x86_64 there is no register stack and function arguments aren't
typically placed on the stack, therefore we aren't able to see the
function arguments in the bt -f output.
Is there a trick to dumping out %rdi, %rsi, %rdx, etc?
I hope this isn't too lame of a question. I'm just getting my toes wet
with x86_64 and kdump/crash.
Thanks in advance,
Paul Sanders
SGI Global Product Support
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6:10 a.m.
Paul Sanders wrote:
Hello all,
I'm trying to get myself ramped to using crash on x86_64.
In x86_64 there is no register stack and function arguments aren't
typically placed on the stack, therefore we aren't able to see the
function arguments in the bt -f output.
Is there a trick to dumping out %rdi, %rsi, %rdx, etc?
I hope this isn't too lame of a question. I'm just getting my toes wet
with x86_64 and kdump/crash.
Thanks in advance,
Paul Sanders
SGI Global Product Support
James is right -- aside from the register dumps with each exception frame,
you're pretty much on your own. You'll have to disassemble the functions
of interest from their last "known" value/location/frame, and following
where the register may be stored on the stack. Sorry -- no tricks...
Dave
9:01 a.m.
Hey, that's what keeps us employed, right?! If it was easy EVERYONE
would be doing it! :-)
Thanks for the input guys.
Paul
On Wed, 3 Sep 2008, Dave Anderson wrote:
Paul Sanders wrote:
> Hello all,
>
> I'm trying to get myself ramped to using crash on x86_64.
>
> In x86_64 there is no register stack and function arguments aren't
> typically placed on the stack, therefore we aren't able to see the
> function arguments in the bt -f output.
>
> Is there a trick to dumping out %rdi, %rsi, %rdx, etc?
>
> I hope this isn't too lame of a question. I'm just getting my toes wet
> with x86_64 and kdump/crash.
>
> Thanks in advance,
>
> Paul Sanders
> SGI Global Product Support
James is right -- aside from the register dumps with each exception frame,
you're pretty much on your own. You'll have to disassemble the functions
of interest from their last "known" value/location/frame, and following
where the register may be stored on the stack. Sorry -- no tricks...
Dave
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3 comments
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participants (3)
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Dave Anderson -
James Washer -
Paul Sanders