Problem with unsigned char * data

Problem with unsigned char * data

[Emilio Ugo GIUFFRIDA]

Gentlemen,

I have a problem with gdb/Insight :-(

On a board, when a "unsigned char *" pointer is badly initialized to 
0xffffffff( that for us is outside the memory ), trying to print the pointer's value in the local variable window or in the watchpoint window makes the GUI crash.

Using the gdb console, the answer is quite verbose, but correct:
(gdb) print pt1
$6 = 
Error: Error in st200emu :  Cannot read buffer at memory adress 0xffffffff
Adaptor error on: read memory access at address  (Exception 5 while executing ROM command)

It seems that gdb tries to read at 0xffffffff and, for pointers to unsigned char, displays by default the string pointed. 

Do you know if there is a gdb option disabling this behaviour?


Best regards,

Emilio


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  			     Emilio Ugo Giuffrida

ST200 Tools Team                        Phone   : +39 0957404514
CMG/MCDT Software Design Center         Fax     : +39 0957404013
ST Microelectronics                     TINA    : 052 4514
Stradale Primosole, 50 			    e-mail  : emilio.giuffrida@st.com
95121 Catania ITALY     

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Re: Problem with unsigned char * data

[Daniel Jacobowitz]

On Thu, May 20, 2004 at 08:08:24PM +0200, Emilio Ugo GIUFFRIDA wrote:
> Gentlemen,
> 
> I have a problem with gdb/Insight :-(
> 
> On a board, when a "unsigned char *" pointer is badly initialized to 
> 0xffffffff( that for us is outside the memory ), trying to print the pointer's value in the local variable window or in the watchpoint window makes the GUI crash.
> 
> Using the gdb console, the answer is quite verbose, but correct:

You probably want to send this to the Insight list then.

> Do you know if there is a gdb option disabling this behaviour?

I don't think so.

-- 
Daniel Jacobowitz

Re: Problem with unsigned char * data

[Andrew Cagney]

> Gentlemen,
> 
> I have a problem with gdb/Insight :-(
> 
> On a board, when a "unsigned char *" pointer is badly initialized to 
> 0xffffffff( that for us is outside the memory ), trying to print the pointer's value in the local variable window or in the watchpoint window makes the GUI crash.
> 
> Using the gdb console, the answer is quite verbose, but correct:
> (gdb) print pt1
> $6 = 
> Error: Error in st200emu :  Cannot read buffer at memory adress 0xffffffff
> Adaptor error on: read memory access at address  (Exception 5 while executing ROM command)
> 
> It seems that gdb tries to read at 0xffffffff and, for pointers to unsigned char, displays by default the string pointed. 
> 
> Do you know if there is a gdb option disabling this behaviour?

Which target are you using?

The message appears to come from the target and that should recover from 
these error conditions reporting them back to GDB.

The other option is to look at the ``mem'' command, it was added to 
address this problem of errant targets (I'm not sure of its status 
though - doesn't appear to be tested).

Andrew