I have this environment systemtap-20070331 snapshot,kernel-2.6.21-rc3,
elfutils-0.125 arch=ppc64.

But execution of current.stp in systemtap-20070331 snapshot is giving spinlock
lockup and softlockup bug. And system is getting freezed.
======================================================
UG: spinlock lockup on CPU#0, sshd/2380, c0000000007da608
Call Trace:
[C0000000076134C0] [C00000000000FAB0] .show_stack+0x68/0x1b0 (unreliable)
[C000000007613560] [C0000000001AF9E8] ._raw_spin_lock+0x140/0x17c
[C000000007613600] [C00000000036B40C] ._spin_lock+0x10/0x24
[C000000007613680] [C00000000006066C] .task_rq_lock+0x68/0xcc
[C000000007613720] [C00000000002B71C] .kretprobe_trampoline_holder+0x0/0x8
[C000000007613810] [C00000000002B71C] .kretprobe_trampoline_holder+0x0/0x8
[C0000000076138C0] [C00000000002B71C] .kretprobe_trampoline_holder+0x0/0x8
[C000000007613970] [C00000000002B71C] .kretprobe_trampoline_holder+0x0/0x8
[C000000007613AC0] [C000000000201358] .pty_write+0x74/0x90
[C000000007613B40] [C0000000001FE05C] .write_chan+0x378/0x448
[C000000007613C20] [C0000000001F9EA0] .tty_write+0x1a0/0x278
[C000000007613CF0] [C0000000000E6938] .vfs_write+0x120/0x1f0
[C000000007613D90] [C0000000000E7368] .sys_write+0x4c/0x8c
[C000000007613E30] [C0000000000086B4] syscall_exit+0x0/0x40
BUG: spinlock lockup on CPU#6, klogd/1887, c0000000007da608
Call Trace:
[C00000000FD173F0] [C00000000000FAB0] .show_stack+0x68/0x1b0 (unreliable)
[C00000000FD17490] [C0000000001AF9E8] ._raw_spin_lock+0x140/0x17c
[C00000000FD17530] [C00000000036B40C] ._spin_lock+0x10/0x24
[C00000000FD175B0] [C00000000006066C] .task_rq_lock+0x68/0xcc
[C00000000FD17650] [C00000000002B71C] .kretprobe_trampoline_holder+0x0/0x8
[C00000000FD17740] [C00000000002B71C] .kretprobe_trampoline_holder+0x0/0x8
[C00000000FD177F0] [C00000000002B71C] .kretprobe_trampoline_holder+0x0/0x8
[C00000000FD178A0] [C00000000002B71C] .kretprobe_trampoline_holder+0x0/0x8
[C00000000FD17930] [C00000000035CF80] .unix_dgram_sendmsg+0x524/0x638
[C00000000FD17A30] [C0000000002C9CE4] .sock_aio_write+0x164/0x19c
[C00000000FD17B60] [C0000000000E5FF0] .do_sync_write+0xc4/0x124
[C00000000FD17CF0] [C0000000000E6954] .vfs_write+0x13c/0x1f0
[C00000000FD17D90] [C0000000000E7368] .sys_write+0x4c/0x8c
[C00000000FD17E30] [C0000000000086B4] syscall_exit+0x0/0x40
=============================================================

But What I observed is, previous week systemtap is not giving any problem at all.
Could the recent transport changes be the reason for this?

------- Additional Comment #1 From Frank Ch. Eigler 2007-04-02 17:06 -------

This is probably a sideeffect of the inline->function changes committed last week.
That is, the script now includes inline functions where it used not to.  Chances
are that both this test script as well as the probing blacklist need to be changed.

------- Additional Comment #2 From Frank Ch. Eigler 2007-04-02 21:12 -------

Another data point: I see this kind of crash (with tracebacks showing
kretprobe_trampoline) on several platforms, but only with very recent
kernels.  Contrary to your apparent experience, it does not go away with
a slightly older systemtap snapshot.  It is as if something has changed
for the worse in recent kernels.