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breakpoints/1219: cannot access subprocess memory


>Number:         1219
>Category:       breakpoints
>Synopsis:       cannot access subprocess memory
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon May 19 14:28:00 UTC 2003
>Closed-Date:
>Last-Modified:
>Originator:     Paul Hewlett
>Release:        5.3 (i686-pc-linux-gnu)
>Organization:
>Environment:
SuSE 8.2 Professional
>Description:
GDB is unable to access the memory of the traced process on SuSE 8.2. I have a program 'testbasic' at which I put a breakpoint at line 1345

        gdb /usr/bin/iss/testbasic

gdb starts. I set a breakpoint -

        break 1345

and run

         run

gets the message 

         Can't get registers...

I downloaded the gdb 5.3 sources and recompiled. The same procedure now reports 

file testbasic.c, line 1345.
(gdb) run
Starting program: /home/iss/9.1.0/lnx9_d/bin/testbasic
Warning:
Cannot insert breakpoint 1.
Error accessing memory address 0x804bfd6: Input/output error.
Cannot insert breakpoint -2.
Error accessing memory address 0x4000bb50: Input/output error.
The same program may be running in another process.

If I start gdb with the --write option viz :

         gdb --write /usr/bin/iss/testbasic

and repeat the breakpoint I get
(gdb) break 1345
Breakpoint 1 at 0x804bfd6: file testbasic.c, line 1345.
(gdb) run
Starting program: /home/iss/9.1.0/lnx9_d/bin/testbasic
/bin/bash: line 1: /home/iss/9.1.0/lnx9_d/bin/testbasic: Text file busy
/bin/bash: line 1: /home/iss/9.1.0/lnx9_d/bin/testbasic: Success

Program exited with code 01.
You can't do that without a process to debug.

I was compiling with -ggdb. I changed to -gdwarf-2 without success



>How-To-Repeat:
See above
>Fix:
I cannot fix this. I looked in the sources but it seems that the
ptrace() procedure fails with some error. Unfortunately I cannot run gdb to debug gdb :-)
>Release-Note:
>Audit-Trail:
>Unformatted:


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