Re: Oops with tip/x86/fpu

Dave Hansen
2015-03-26T22:43:51Z

On 03/26/2015 03:37 PM, Yu, Fenghua wrote:
>> > void sighup(int sig, siginfo_t *info, void *ctxt) {
>> > struct ucontext *uctxt = ctxt;
>> > struct sigcontext *sctxt = (void*)&uctxt->uc_mcontext;
>> >
>> > printf("SIGHUP! %p\n", sctxt->fpstate);
>> > sctxt->fpstate = (void *)1;
> sctxt->fpstate=(void *)1 changes the fpstate pointer in the sigcontext. It will generate segfault and bad frame info in kernel.
>
> This is expected behavior, right? Is this still a valid test?

Just to be clear, I saw a full-on kernel panic induced from an
unprivileged application.

Are you seeing something different?