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Debugging standard C library routines

I am working on MontaVista Linux on a PPC board.
The compiler I am using is a gnu cross compiler cross compiler
(ppc-82xx-gcc)

The application/software that is being run, is messing up the memory
due to which a subsequent malloc fails.

When the application core is dumped I do not get any backtrace in the
code (although the application is compiled with debug symbols, with -g
option). The only thing I get is the address of the function (and not
the name) where the crash is happening.

Using prints in the code I found that application crashes while calling
malloc. I am linking the standard C library as .so, and thats probably
why there is not backtrace conatining the functions of my application.

There is not enough memory on the board to run gdb. Also due to the
complexity of the scenarios it is not always possible to run gdbserver.
It there a possible way to:
1. Link a debuggable version of stdlib which would put more information
in the core, when it is dumped.
2. Can I enable some asserts or extra information in stdlib which would
tell me if memry is being messed up.
3. Is there a way by which I can map an address to a function of .so
loaded in the memory. Or even if i know that the address belongs t a
perticaular .so

Thanks in advance.

Sep 30 '06
83 4018
Frederick Gotham <fg*******@SPAM .comwrites:
Old Wolf posted:
>> int const assert_dummy = (assert(!!arg), 0);

Is this supposed to be an improvement on:
assert(arg);

You can't mix statements and declarations in C (within a block).
You can in C99.
>? And what is the '!!' doing?

The argument to "assert" must be of the type, int.
In C99, it merely has to be a scalar expression.

[snip]
>> return (void)assert_du mmy, retval;

Huh?

The cast-to-void is intended to suppress a compiler warning regarding non-
usage of a variable.
It may or may not do so, depending on the compiler.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.
Oct 15 '06 #81
in 701336 20061015 152559 Frederick Gotham <fg*******@SPAM .comwrote:
>int i; To hold the amount of chickens

It's "number of chickens".

(You'd need a float to hold the amount of chicken ;-) )
Oct 16 '06 #82
Bob Martin wrote:
in 701336 20061015 152559 Frederick Gotham <fg*******@SPAM .comwrote:
>int i; To hold the amount of chickens


It's "number of chickens".

(You'd need a float to hold the amount of chicken ;-) )
No, you need float for ducks.
--
Flash Gordon
Oct 19 '06 #83
Flash Gordon <sp**@flash-gordon.me.ukwri tes:
Bob Martin wrote:
>in 701336 20061015 152559 Frederick Gotham <fg*******@SPAM .comwrote:
>>int i; To hold the amount of chickens
It's "number of chickens".
(You'd need a float to hold the amount of chicken ;-) )

No, you need float for ducks.
No, the ducks can float by themselves, so you need a float for the
chickens.

You get down off a duck.

But we should really be talking about C gulls.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.
Oct 19 '06 #84

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