On Thu, Jul 23, 2015 at 03:37:48PM -0700, Andy Lutomirski wrote: > There's nothing IST-worthy about #BP/int3. We don't allow kprobes > in the small handful of places in the kernel that run at CPL0 with > an invalid stack, and 32-bit kernels have used normal interrupt > gates for #BP forever. > > Furthermore, we don't allow kprobes in places that have usergs while > in kernel mode, so "paranoid" is also unnecessary. > > Signed-off-by: Andy Lutomirski <l...@kernel.org> > --- > arch/x86/entry/entry_64.S | 2 +- > arch/x86/kernel/traps.c | 26 +++++++++++++------------- > 2 files changed, 14 insertions(+), 14 deletions(-)
... > @@ -494,7 +494,15 @@ dotraplinkage void notrace do_int3(struct pt_regs *regs, > long error_code) > if (poke_int3_handler(regs)) > return; > > + /* > + * Use ist_enter despite the fact that we don't use an IST stack. > + * We can be called from a kprobe in non-CONTEXT_KERNEL kernel > + * mode or even during context tracking state changes. > + * > + * This means that we can't schedule. That's okay. > + */ > ist_enter(regs); A good sign that this "ist_enter" name needs to be changed. Otherwise, this call site will confuse people. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/