Disassemble arbitrary memory with disas?

Disassemble arbitrary memory with disas?

[Toshi Morita]

I'm currently debugging a JIT which dynamically generates code, and I'd like to disassemble it with the "disas" command in GDB.

However, since there isn't any symbolic information for the buffer in which the code is generated, GDB refuses to disassemble.

Is there a way to do this? 

Please reply to tm314159 at yahoodotcom since I don't normally read this list.

Toshi



      

Re: Disassemble arbitrary memory with disas?

[Joel Brobecker]

> I'm currently debugging a JIT which dynamically generates code, and
> I'd like to disassemble it with the "disas" command in GDB.
> 
> However, since there isn't any symbolic information for the buffer in
> which the code is generated, GDB refuses to disassemble.

I think that the "x /i" command should work. Have a look at the GDB
documentation on the "x" command, it should give you more details
about how to use the /something modifiers.

-- 
Joel

Re: Disassemble arbitrary memory with disas?

[Jonas Maebe]

On 22 May 2009, at 23:44, Joel Brobecker wrote:

> I think that the "x /i" command should work. Have a look at the GDB
> documentation on the "x" command, it should give you more details
> about how to use the /something modifiers.

Indeed. An alternative is "disassemble <start_address>  
<stop_address>". "x/10i <address>" is easier to type though :)


Jonas

Re: Disassemble arbitrary memory with disas?

[Andreas Schwab]

Toshi Morita <tm314159@yahoo.com> writes:

> I'm currently debugging a JIT which dynamically generates code, and I'd like to disassemble it with the "disas" command in GDB.
>
> However, since there isn't any symbolic information for the buffer in which the code is generated, GDB refuses to disassemble.
>
> Is there a way to do this? 

(gdb) help disass
Disassemble a specified section of memory.
Default is the function surrounding the pc of the selected frame.
With a /m modifier, source lines are included (if available).
With a single argument, the function surrounding that address is dumped.
Two arguments are taken as a range of memory to dump.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: Disassemble arbitrary memory with disas?

[Toshi Morita]

Thanks a lot!!
Will try it when I get back in the office on Tuesday!

Toshi

--- On Fri, 5/22/09, Jonas Maebe <jonas.maebe@elis.ugent.be> wrote:

> From: Jonas Maebe <jonas.maebe@elis.ugent.be>
> Subject: Re: Disassemble arbitrary memory with disas?
> To: "Joel Brobecker" <brobecker@adacore.com>
> Cc: "Toshi Morita" <tm314159@yahoo.com>, gdb@sourceware.org
> Date: Friday, May 22, 2009, 2:51 PM
> 
> On 22 May 2009, at 23:44, Joel Brobecker wrote:
> 
> > I think that the "x /i" command should work. Have a
> look at the GDB
> > documentation on the "x" command, it should give you
> more details
> > about how to use the /something modifiers.
> 
> Indeed. An alternative is "disassemble
> <start_address> <stop_address>". "x/10i
> <address>" is easier to type though :)
> 
> 
> Jonas
>