BUG: GDB >=6 vfork from pthread fails with 2.6 vanilla kernels

Jonathan A. George JAGeorge@greshamstorage.com
Fri May 14 15:13:00 GMT 2004


BUG: GDB >=6 vfork from pthread fails with 2.6 vanilla kernels

Very simple to duplicate:
Run popen() from within a pthread_create() thread while sleeping in the 
base process.

(NOTE: works perfectly outside of GDB and under GDB with 2.4 kernel 
pthreads)

Environment:
Any 2.6 series kernel (tested 2.6.0 - 2.6.6 vanilla kernel.org)
Any GDB (tested 6.0 - current CVS)
Any GCC linked with -lpthread (tested 3.0.4 - 3.3.3)

GDB output from test program:
Detaching after fork from child process 7020.
warning: Unexpected waitpid result 00117f when waiting for vfork-done
linux-nat.c:450: internal-error: unknown ptrace event 5
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)

Observations:
It seems as if GDB in linux-nat.c is trying to associate the vfork()d 
popen()d process with the root process instead of the parenting thread 
started by the root process.



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