> Hi, John
>
> [Sorry resend this mail, with pure text format and CC to Linux-kernel. ]
>
> I saw you submitted a patch for X86_64 to prevent a oops, here is the
> hyper-link i google:
>
http://marc.info/?l=git-commits-head&m=113979973412652&w=2
>
> There is an obvious problem for your patch , see my comment at "=====>"
>
> /* runs on IST stack. */
> asmlinkage void __kprobes do_debug(struct pt_regs * regs,
> unsigned long error_code)
> {
>
> - conditional_sti(regs);
> + preempt_conditional_sti(regs);
>
>
> force_sig_info(SIGTRAP, &info, tsk);=====> /*this function try
> spin_lock_irqsave(&t->sighand->siglock, flags); generate more
> warnings*/
>
>
> clear_dr7:
> set_debugreg(0UL, 7);
> + preempt_conditional_cli(regs);
> return;
>
> clear_TF_reenable:
> set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
> regs->eflags &= ~TF_MASK;
> + preempt_conditional_cli(regs);
>
> }
>
>
> here is the trace result, founded on linux2.6.25.4 with realtime
> patch(not only do_debug, do_int3,do_stack_segment also has same
> problem ):
>
> BUG: sleeping function called from invalid context
> usermode-agent(2302) at kernel/rtmutex.c:626
>
> in_atomic():1 [00000001], irqs_disabled():0
>
> Call Trace:
> <#DB> [<ffffffff80227177>] __might_sleep+0x107/0x110
> [<ffffffff804ec510>] __rt_spin_lock+0x30/0x60
> [<ffffffff804ec549>] rt_spin_lock+0x9/0x10
>
> [<ffffffff8023cf2f>] force_sig_info+0x2f/0xd0
> [<ffffffff8020cdab>] do_debug+0x17b/0x220
> [<ffffffff804ed1b3>] debug+0x93/0x9f
> <<EOE>>
