Re: gdb steps into glibc functions

[Marc Gonzalez-Sigler <marc.gonzalez-sigler@inria.fr>]

Hi,

First of all, I thank you and Daniel for answering my question. 
Daniel's suggestion to set auto-solib-add to 0 proved very useful.

Michael Elizabeth Chastain wrote:
> Hello,
> 
> 
>>GNU gdb 5.0rh-5 Red Hat Linux 7.1
> 
> 
> That is a very old gdb, and a very old Red Hat Linux, too.
> 
> The current releases are: gdb 6.0 and Red Hat Linux 9.

Unfortunately, I have no control over this.

> Look at the value of the environment variable LD_LIBRARY_PATH.
> In particular, see if there is a "/usr/lib/debug" in there.
> Red Hat ships the normal non-debug version of glibc in /lib,
> and the debugging version in /usr/lib/debug.  I don't know if
> it was that way back in 7.1, but it likely was.

$ echo $LD_LIBRARY_PATH
/usr/lib:/orc-2.1/usr/ia64-orc-linux/lib/gcc-lib/ia64-orc-linux/2.1

$ ls /usr/lib/debug
ls: /usr/lib/debug: No such file or directory

> Also try "ldd program" on your program and see how the glibc
> reference is getting resolved.

$ ldd /orc-2.1/usr/ia64-orc-linux/bin/ir_b2a
	libm.so.6 => /lib/libm.so.6 (0x40028000)
	libc.so.6 => /lib/libc.so.6 (0x4004a000)
	/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)

$ ls -l /lib/libc.*
lrwxrwxrwx    1 root     root           13 Mar 13  2002 
/lib/libc.so.6 -> libc-2.2.4.so

$ ls -l /lib/libc-2.2.4.so
-rwxr-xr-x    1 root     root      5723311 Dec  8  2001 
/lib/libc-2.2.4.so

> You can probably strip the library with "strip --strip-debug"
> but it's tricky to do *anything* to glibc on a running system,
> because all the processes on the system have mmap'ed that file.
> If you could boot from a CD-ROM then it would be safer to modify
> glibc.  And for your sake, make a backup of the original glibc in
> another directory before you touch glibc.

I think I will stick with Daniel's solution :-)

> Also, use "next" instead of "step".  "next" always skips over the
> function.  That would give you the behavior you want, without having
> to change anything.

Not really. I do want to step into my code, not the glibc code.

Marc