Hi Andrew,
Andrew Paprocki wrote:
>> Why not use watchpoints (::wp)?
>> max
>>
>
> Watchpoints assume you know the address you want to watch. I want to
> dynamically print out any 'common' variable that any of the executing code
> reads/writes. This requires looking at the current instruction, decoding any
> memory address it is reading/writing, and looking up the symbol at that
> address to determine if it is a 'common' linkage symbol.
>
> I guess I'm wondering if mdb_readsym() or mdb_readvar() can be used to read
> registers, or if mdb is lacking this functionality and needs a mdb_readreg()
> function added to its API to programmatically get the ::regs values.
>
I see. You want to trace data (analogous to the way dtrace can trace
code), with mdb?
The registers exist as variables in mdb. You could use:
mdb_snprintf(buffer, sizeof(buffer), "<%s=K", register_name);
mdb_eval(buffer);
Where register_name is a string representing the name of the register.
So, in mdb
you can say, for instance,
<eax=K
and it will print the current value of the eax register. If you want
symbol names,
use "/" instead of "=" in the "<%s=K" format string.
Other than that, I think you would have to abandon the API. Mdb stores
variables in an nvlist at mdb.m_nv (see mdb_tgt_register_regvars() in
the mdb
source). I would give you a link, but opensolaris.org is not currently
responding.
max
