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From: "reid.kleckner at gmail dot com" <sourceware-bugzilla@sourceware.org>
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Subject: [Bug gdb/15093] New: gdb cannot follow cross-arch execve from x86_64
 to i386
Date: Sat, 02 Feb 2013 17:08:00 -0000
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http://sourceware.org/bugzilla/show_bug.cgi?id=15093

             Bug #: 15093
           Summary: gdb cannot follow cross-arch execve from x86_64 to
                    i386
           Product: gdb
           Version: 7.5
            Status: NEW
          Severity: normal
          Priority: P2
         Component: gdb
        AssignedTo: unassigned@sourceware.org
        ReportedBy: reid.kleckner@gmail.com
    Classification: Unclassified


This doesn't work for me on my system:

$ cat hello.c
#include <stdio.h>
int main(void) {
    printf("hello, world!\n");
    return 0;
}

$ gcc -m32 hello.c -o hello

$ ./hello
hello, world!

$ gdb --args /bin/bash -norc -c ./hello
...
(gdb) run
Starting program: /bin/bash -norc -c ./hello
process 25845 is executing new program:
/usr/local/google/home/rnk/dynamorio/build/hello
warning: Selected architecture i386 is not compatible with reported target
architecture i386:x86-64
Architecture of file not recognized.
(gdb) 

>>From then on I can't debug hello.  It keeps pretending it's a 64-bit process.

I can easily debug ./hello directly with this version of gdb, so I don't see
why it can't follow the execve.  I tried various things like set arch i386 and
file ./hello, but it doesn't get gdb to do the right thing.

Is this supposed to work?  I'm not sure if what I'm asking for is a bug report
or a feature request.

This is using Google's patched version of gdb:
$ gdb --version
GNU gdb (GDB) 7.5-gg7

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