Reflections on OS integration Eric Schrock's Weblog
Musings about Fishworks, Operating Systems, and the software that runs on them.

« Previous day (Jun 16, 2005) | Main | Next day (Jun 18, 2005) »

Friday Jun 17, 2005

Observability in OpenSolaris

Just a heads up that we've formed a new OpenSolaris Observability community. There's not much there night now, but I encourage to head over and check out what OpenSolaris has to offer. Or come to the discussion forum and gripe about what features we're still missing. Topics covered include process, system, hardware, and post mortem observability. We'll be adding much more content as soon as we can.

Technorati Tag:

Posted at 05:39PM Jun 17, 2005 by eschrock in OpenSolaris | Comments[2] | Permalink

GDB to MDB Migration, Part Two

So talking to Ben last night convinced me I needed to finish up the GDB to MDB reference that I started last month. So here's part two.

GDBMDBDescription

Program Stack

backtrace n::stack
$C		 Display stack backtrace for the current thread
-thread::findstack -v Display a stack for a given thread. In the kernel, thread is the address of the kthread_t. In userland, it's the thread identifier.
info ...- Display information about the current frame. MDB doesn't support the debugging data necessary to maintain the frame abstraction.

Execution Control

continue
c		:c Continue target.
stepi
si		::step
]		 Step to the next machine instruction. MDB does not support stepping by source lines.
nexti
ni		::step over
[		 Step over the next machine instruction, skipping any function calls.
finish::step out Continue until returning from the current frame.
jump *addressaddress>reg Jump to the given location. In MDB, reg depends on your platform. For SPARC it's 'pc', for i386 its 'eip', and for amd64 it's 'rip'.

Display

print expraddr::print expr Print the given expression. In GDB you can specify variable names as well as addresses. For MDB, you give a particular address and then specify the type to display (which can include dereferencing of members, etc).
print /faddr/f Print data in a precise format. See ::formats for a list of MDB formats.
disassem addraddr::dis Dissasemble text at the given address, or the current PC if no address is specified

This is just a primer. Both programs support a wide variety of additional options. Running 'mdb -k', you can quickly see just how many commands are out there:

> ::dcmds ! wc -l
     385
> ::walkers ! wc -l
     436

One helpful trick is ::dcmds ! grep thing, which searches the description of each command. Good luck, and join the discussion over at the OpenSolaris MDB community if you have any questions or tips of your own.

Technorati tag:
Technorati tag:
Technorati tag:

Posted at 10:22AM Jun 17, 2005 by eschrock in OpenSolaris | Comments[2] | Permalink

Archives

« June 2005 »
SunMonTueWedThuFriSat
   
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
  
       
Today

Fishworks

Other Blog Links

Today's Page Hits: 293