Re: [Crash-utility] Use crash with KVM memory dump?
----- Original Message -----
hi,
i dump the whole memory of a KVM guest out using "dump-guest-memory". as a
result, now i have a big ELF file. i want to use "crash" to analyze this
dump file.
the question is: given the RIP address of an instruction in the KVM guest -
for example 0x12345, which is virtual address, how can "crash" tell me where
in the dump is the position of 0x12345? is there such a command for this?
Is the RIP in user-space or kernel-space? If I understand your question correctly,
you can enter "vtop" of the RIP to get the physical address, but if it's a
user-space address, you must ensure that you have "set" the context to the
PID/task-address of the task whose user-space memory you want to look at.
my intention is to locate the place, and analyze the assembly instruction
around that RIP to see what is running at the time i dumped the KVM memory.
You really don't need to know where in the dumpfile the RIP is located
for disassembly. If it's kernel-space you're interested in, then you
can just do "dis -rl <RIP-address>" to see the sequence of instructions
leading up to the RIP. If it's user-space, there's no way to determine
the beginning of the user-space function that was running, so the best
you can do is to "set" your context to the task you're interested in,
and do a "dis -u <user-space-RIP> <count>" to see where it was, and
where
it would be going to.
Dave
thank a lot,
Jun