Messages in this thread | | | Date | Fri, 5 Aug 2022 10:09:15 -0700 | From | Ira Weiny <> | Subject | Re: [PATCH v3] x86,mm: print likely CPU at segfault time |
| |
On Fri, Aug 05, 2022 at 04:27:40PM +0200, Borislav Petkov wrote: > On Fri, Aug 05, 2022 at 10:16:44AM -0400, Rik van Riel wrote: > > diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c > > index fad8faa29d04..c7a5bbf40367 100644 > > --- a/arch/x86/mm/fault.c > > +++ b/arch/x86/mm/fault.c > > @@ -769,6 +769,8 @@ show_signal_msg(struct pt_regs *regs, unsigned long error_code, > > unsigned long address, struct task_struct *tsk) > > { > > const char *loglvl = task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG; > > + /* This is a racy snapshot, but it's better than nothing. */ > > + int cpu = raw_smp_processor_id(); > > Please read this in exc_page_fault() and hand it down to helpers. > > Alternatively, I'm being told there's a patchset in the works which > will allow for any exception handler to pass in additional information > downwards through an extended pt_regs. Then, saving the CPU number on > which the handler is running would work generically everywhere.
Indeed that was part of the PKS series.[1]
I've thrown together a quick RFC with the relevant patches from that series and Rik's code in show_signal_msg().
I'll post it shortly, Ira
[1] https://lore.kernel.org/lkml/20220419170649.1022246-18-ira.weiny@intel.com/
> > Thx. > > -- > Regards/Gruss, > Boris. > > https://people.kernel.org/tglx/notes-about-netiquette >
| |