Re: GDB and 64-bit solaris

[Paul Hilfinger <hilfingr at EECS dot Berkeley dot EDU>]

Cheers, 

There have been a couple of questions recently (one from me) regarding 
GDB on 64-bit SPARC Solaris executables.  I have a little information.

1. An error such as

    (gdb) b main
    Cannot access memory at address 0x0

on an executable with debugging information may be due to the use of
stabs debugging info, which I gather does not support 64-bit
addresses.  For example, you won't see this error in the absence 
of debugging info (where the minimal symbols are used).

2. An error such as 

    (gdb) run
    Starting program: /export/home/users/hilfingr/gdb/test64 
    procfs:3887 -- process not stopped.    <<<< ?????
    procfs: ...giving up...

results from attempting to debug a 64-bit executable process from a 32-
bit-compiled GDB.  What happens specifically is that all attempts to
read from /proc/xxxxx/status result in an EOVERFLOW error, with no
data read.  The process actually IS stopped, but since at the moment
GDB 5 does not check that its procinfo calls succeed, you get the
message in this form instead, when later parts of procfs_wait read the
flags and find 0's for what should be the flags indicating that the
process is stopped.

Mind you, various annoyances have prevented me from getting a version
that actually DOES work yet on Solaris, and I can't vouch for all
releases of Solaris (this info is from a 2.7 version of the OS).
However, this at least indicates one problem one might face.

Paul Hilfinger
UC Berkeley & ACT Corp.