[Bug threads/9817] New: GDB goes to 100% CPU usage indefinitely if pthread stack address is modified

[Bug threads/9817] New: GDB goes to 100% CPU usage indefinitely if pthread stack address is modified

[mihai dot stanescu at gmail dot com]

The particular thing about the program is that is doing a pthread_attr_setstack
to setup the thread stack to a dynamically allocated memory area on heap.

pthread_attr_setstack(&attr, alignedStackBase, THREAD_STACK_SIZE -
2*PTHREAD_STACK_MIN)

When attaching to an already running program (which uses pthreads) on
gentoo/x86, GDB loops indefinitely 

Here is a small dump from strace which goes forever

open("/proc/6204/mem", O_RDONLY|O_LARGEFILE) = 7
pread64(7,"\220{\237\266\220\r\253\27\220{\237\266\1\0\0\0\200\351\363\267\0\0\n\377,DRv\0\0\0\0"...,1136,
3063905168) = 1136
close(7) = 0
open("/proc/6204/mem", O_RDONLY|O_LARGEFILE) = 7
pread64(7,
"\220;\254\266\210\1\253\27\220;\254\266\1\0\0\0\200\351\363\267\0\0\n\377,DRv\0\0\0\0"...,1136,
3064740752) = 1136
close(7)                                = 0
open("/proc/6204/mem", O_RDONLY|O_LARGEFILE) = 7
pread64(7,"\220;\254\266\210\1\253\27\220;\254\266\1\0\0\0\200\351\363\267\0\0\n\377,DRv\0\0\0\0"...,1136,
3064740752) = 1136
close(7)                                = 0

-- 
           Summary: GDB goes to 100% CPU usage indefinitely if pthread stack
                    address is modified
           Product: gdb
           Version: 6.8
            Status: UNCONFIRMED
          Severity: normal
          Priority: P1
         Component: threads
        AssignedTo: unassigned at sourceware dot org
        ReportedBy: mihai dot stanescu at gmail dot com
                CC: gdb-prs at sourceware dot org


http://sourceware.org/bugzilla/show_bug.cgi?id=9817

------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.

[Bug threads/9817] GDB goes to 100% CPU usage indefinitely if pthread stack address is modified

[mihai dot stanescu at gmail dot com]

------- Additional Comments From mihai dot stanescu at gmail dot com  2009-02-04 12:05 -------
*** Bug 9815 has been marked as a duplicate of this bug. ***

-- 


http://sourceware.org/bugzilla/show_bug.cgi?id=9817

------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.

[Bug gdb/9817] GDB goes to 100% CPU usage indefinitely if pthread stack address is modified

[mihai dot stanescu at gmail dot com]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|threads                     |gdb


http://sourceware.org/bugzilla/show_bug.cgi?id=9817

------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.

[Bug threads/9817] GDB goes to 100% CPU usage indefinitely if pthread stack address is modified

[mihai dot stanescu at gmail dot com]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|gdb                         |threads


http://sourceware.org/bugzilla/show_bug.cgi?id=9817

------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.

[Bug threads/9817] GDB goes to 100% CPU usage indefinitely if pthread stack address is modified

[pedro at codesourcery dot com]

------- Additional Comments From pedro at codesourcery dot com  2009-02-04 13:09 -------
Subject: Re:  New: GDB goes to 100% CPU usage indefinitely if pthread stack address is modified

Hi,

On Wednesday 04 February 2009 12:03:33, mihai dot stanescu at gmail dot com wrote:
> The particular thing about the program is that is doing a pthread_attr_setstack
> to setup the thread stack to a dynamically allocated memory area on heap.
> 
> pthread_attr_setstack(&attr, alignedStackBase, THREAD_STACK_SIZE -
> 2*PTHREAD_STACK_MIN)
> 

Any chance you have a minimal test app you could attach that reproduce
the problem?

There have been numerous fixes since gdb 6.8.  Could you please try
what happens with a recent gdb snapshot (or cvs head)?

Thanks,



-- 


http://sourceware.org/bugzilla/show_bug.cgi?id=9817

------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.

[Bug threads/9817] GDB goes to 100% CPU usage indefinitely if pthread stack address is modified

[mihai dot stanescu at gmail dot com]

------- Additional Comments From mihai dot stanescu at gmail dot com  2009-02-05 10:32 -------

I tried with gdb-6.8.50.20090205.tar.bz2 and same problem. I will try to make a
sample program for you.


(In reply to comment #2)
> Subject: Re:  New: GDB goes to 100% CPU usage indefinitely if pthread stack
address is modified
> 
> Hi,
> 
> On Wednesday 04 February 2009 12:03:33, mihai dot stanescu at gmail dot com wrote:
> > The particular thing about the program is that is doing a pthread_attr_setstack
> > to setup the thread stack to a dynamically allocated memory area on heap.
> > 
> > pthread_attr_setstack(&attr, alignedStackBase, THREAD_STACK_SIZE -
> > 2*PTHREAD_STACK_MIN)
> > 
> 
> Any chance you have a minimal test app you could attach that reproduce
> the problem?
> 
> There have been numerous fixes since gdb 6.8.  Could you please try
> what happens with a recent gdb snapshot (or cvs head)?
> 
> Thanks,
> 
> 



-- 


http://sourceware.org/bugzilla/show_bug.cgi?id=9817

------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.

[Bug threads/9817] GDB goes to 100% CPU usage indefinitely if pthread stack address is modified

[mihai dot stanescu at gmail dot com]

------- Additional Comments From mihai dot stanescu at gmail dot com  2009-02-05 11:18 -------

I did also a small test program but i could not reproduce the problem. Is not
like our application (which is a lot bigger. Our executable has 300MB in debug) 

Also loads

Loaded symbols for /lib/libpthread.so.0
Reading symbols from /lib/libdl.so.2...done.
Loaded symbols for /lib/libdl.so.2
Reading symbols from /usr/lib/gcc/i686-pc-linux-gnu/4.2.3/libstdc++.so.6...done.
Loaded symbols for /usr/lib/gcc/i686-pc-linux-gnu/4.2.3/libstdc++.so.6
Reading symbols from /lib/libm.so.6...done.
Loaded symbols for /lib/libm.so.6
Reading symbols from /usr/lib/gcc/i686-pc-linux-gnu/4.2.3/libgcc_s.so.1...done.
Loaded symbols for /usr/lib/gcc/i686-pc-linux-gnu/4.2.3/libgcc_s.so.1
Reading symbols from /lib/libc.so.6...done.
Loaded symbols for /lib/libc.so.6
Reading symbols from /usr/lib/liblber-2.3.so.0...done.
Loaded symbols for /usr/lib/liblber-2.3.so.0
Reading symbols from /lib/libresolv.so.2...done.
Loaded symbols for /lib/libresolv.so.2
Reading symbols from /usr/lib/libssl.so.0.9.8...done.
Loaded symbols for /usr/lib/libssl.so.0.9.8
Reading symbols from /usr/lib/libcrypto.so.0.9.8...done.
Loaded symbols for /usr/lib/libcrypto.so.0.9.8
Reading symbols from /lib/ld-linux.so.2...done.
Loaded symbols for /lib/ld-linux.so.2
Reading symbols from /lib/libnss_compat.so.2...done.
Loaded symbols for /lib/libnss_compat.so.2
Reading symbols from /lib/libnsl.so.1...done.
Loaded symbols for /lib/libnsl.so.1
Reading symbols from /lib/libnss_nis.so.2...done.
Loaded symbols for /lib/libnss_nis.so.2
Reading symbols from /lib/libnss_files.so.2...done.
Loaded symbols for /lib/libnss_files.so.2
0xb7f64882 in ?? () from /lib/ld-linux.so.2

My test program only loads:
Loaded symbols for /lib/libpthread.so.0
Reading symbols from /lib/libdl.so.2...done.
Loaded symbols for /lib/libdl.so.2
Reading symbols from /usr/lib/gcc/i686-pc-linux-gnu/4.2.3/libstdc++.so.6...done.
Loaded symbols for /usr/lib/gcc/i686-pc-linux-gnu/4.2.3/libstdc++.so.6
Reading symbols from /lib/libm.so.6...done.
Loaded symbols for /lib/libm.so.6
Reading symbols from /usr/lib/gcc/i686-pc-linux-gnu/4.2.3/libgcc_s.so.1...done.
Loaded symbols for /usr/lib/gcc/i686-pc-linux-gnu/4.2.3/libgcc_s.so.1
Reading symbols from /lib/libc.so.6...done.
Loaded symbols for /lib/libc.so.6
Reading symbols from /lib/ld-linux.so.2...done.
Loaded symbols for /lib/ld-linux.so.2
0xb7f35882 in ?? () from /lib/ld-linux.so.2


Sorry.

-- 


http://sourceware.org/bugzilla/show_bug.cgi?id=9817

------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.

[Bug threads/9817] GDB goes to 100% CPU usage indefinitely if pthread stack address is modified

[dje at google dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=9817

dje at google dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dje at google dot com

-- 
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.