Re: breakpoints/2295: gdb stuck while debugging Xorg

Re: breakpoints/2295: gdb stuck while debugging Xorg

[Bernardo Innocenti]

The following reply was made to PR breakpoints/2295; it has been noted by GNATS.

From: Bernardo Innocenti <bernie@codewiz.org>
To: gdb-gnats@sources.redhat.com
Cc: gdb@sourceware.org
Subject: Re: breakpoints/2295: gdb stuck while debugging Xorg
Date: Wed, 22 Aug 2007 22:47:18 -0400

 Has anybody some time to analyze this bug?  It's pretty important to us.
 
 -- 
    // Bernardo Innocenti
  \X/  http://www.codewiz.org/

Re: breakpoints/2295: gdb stuck while debugging Xorg

[Daniel Jacobowitz]

The following reply was made to PR breakpoints/2295; it has been noted by GNATS.

From: Daniel Jacobowitz <drow@false.org>
To: Bernardo Innocenti <bernie@codewiz.org>
Cc: gdb-gnats@sources.redhat.com, gdb@sourceware.org
Subject: Re: breakpoints/2295: gdb stuck while debugging Xorg
Date: Wed, 22 Aug 2007 22:59:19 -0400

 On Wed, Aug 22, 2007 at 10:47:18PM -0400, Bernardo Innocenti wrote:
 > Has anybody some time to analyze this bug?  It's pretty important to us.
 
 No.  There's not enough information in the bug to make an educated
 guess, and the bug itself is dependent on your setup; it's unlikely
 that anyone will set up a debuggable Xorg build to look at it.  If you
 can't make a smaller test case, I suggest you build a GDB with debug
 symbols and try to figure out what it is doing.  There are also a
 number of things under "set debug" that you can try, like set debug
 infrun.  If you add more information, maybe someone will recognize the
 problem.
 
 -- 
 Daniel Jacobowitz
 CodeSourcery

breakpoints/2295: gdb stuck while debugging Xorg

[bernie]

>Number:         2295
>Category:       breakpoints
>Synopsis:       gdb stuck while debugging Xorg
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Aug 04 18:08:01 UTC 2007
>Closed-Date:
>Last-Modified:
>Originator:     bernie@codewiz.org
>Release:        gdb-6.6-15.fc7
>Organization:
>Environment:

>Description:
While debugging the X server, I do:

(gdb) b pixman_rasterize_trapezoid
[run an X test client]
Breakpoint 1 at 0xb7ef1519: file pixman-trap.c, line 162.
(gdb) n

At this point, the GDB process gets stuck forever
in "RUN" status.  ^C does not wake it up.

I don't have gdb built with debugging, but I can
still see the following backtrace:

0x0808336f in lookup_minimal_symbol_by_pc_section ()
(gdb) bt
#0  0x0808336f in lookup_minimal_symbol_by_pc_section ()
#1  0x08100e2b in find_pc_sect_psymtab ()
#2  0x08100fa1 in find_pc_sect_symtab ()
#3  0x080ff2d9 in blockvector_for_pc_sect ()
#4  0x080ff317 in block_for_pc_sect ()
#5  0x080ff359 in block_for_pc ()
#6  0x080d59a2 in get_pc_function_start ()
#7  0x081a49b7 in frame_func_unwind ()
#8  0x0816acb0 in ?? ()
#9  0x081a31d7 in get_frame_id ()
#10 0x081159da in ?? ()
#11 0x0811754a in handle_inferior_event ()
#12 0x08118aac in wait_for_inferior ()
#13 0x08118c4d in proceed ()
#14 0x08111e92 in ?? ()
#15 0x08085e23 in execute_command ()
#16 0x0812472f in ?? ()
#17 0x08125332 in ?? ()
#18 0x081d9bd4 in rl_callback_read_char ()
#19 0x0812490b in ?? ()
#20 0x0812427e in ?? ()
#21 0x08123739 in ?? ()
#22 0x08123f08 in gdb_do_one_event ()
---Type <return> to continue, or q <return> to quit---
#23 0x08120cc3 in catch_errors ()
#24 0x080cbb97 in ?? ()
#25 0x0812116f in current_interp_command_loop ()
#26 0x0807f11b in ?? ()
#27 0x08120cc3 in catch_errors ()
#28 0x0807f8c8 in ?? ()
#29 0x08120cc3 in catch_errors ()
#30 0x0807f101 in gdb_main ()
#31 0x0807f0c5 in main ()
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: