Hi Vivek,
One other thing. This probably belongs in the mdb-discuss list. It
would be really nice if dtrace
had a way to allow "::print ..." from within the D language. I have
asked for this, but I don't have a
good way to do it.
max
Vivek Joshi wrote:
>
> Hello Max,
>
> I attached the process while running the mdb (mdb -p <pid>). I didn't
> set the breakpoint earlier ... But I checked it now like this,
>
> > :b 0xFE97B924
> >
>
> Once the program is stopped and I can now print this structure,
> > 0xFE97B924::print struct uscsi_cmd
> {
> uscsi_flags = 0
> uscsi_status = 0
> uscsi_timeout = 0
> uscsi_cdb = 0
> uscsi_bufaddr = 0x46a83f18
> uscsi_buflen = 0
> uscsi_resid = 0x46a83f18
> uscsi_cdblen = 0
> uscsi_rqlen = 0
> uscsi_rqstatus = 0
> uscsi_rqresid = 0
> uscsi_rqbuf = 0x46a83f18
> uscsi_reserved_5 = 0
> }
>
> which too doesn't look valid ... or there might be an issue with the
> application while forming the cdb.
>
> Cheers,
> Vivek
>
>
>
>
> How are you setting the breakpoint with mdb? I assume you are setting
> the breakpoint in your application
> at the place where the ioctl is being called? If you are trying to set
> the breakpoint in the kernel, you won't be able
> to dump the uscsi_cmd with the address truss shows you. That
> address is
> a user address. Also, you have no
> NULL pointer in your truss output. The message "mdb: failed to
> read data
> from target: no mapping for address"
> means that the virtual address you specified (0xfe97b924) has no
> mapping
> in the target in which you are running
> mdb. It is possible that a member of the uscsi_cmd struct is not
> valid.
> How are you running mdb?
>
> max
>
>
