Messages in this thread | | | Date | Thu, 1 Mar 2018 13:03:26 +0100 | From | Joerg Roedel <> | Subject | Re: [PATCH 12/31] x86/entry/32: Add PTI cr3 switch to non-NMI entry/exit points |
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On Tue, Feb 27, 2018 at 02:18:36PM -0500, Waiman Long wrote: > On 02/09/2018 04:25 AM, Joerg Roedel wrote: > > SAVE_ALL > > ENCODE_FRAME_POINTER > > + > > + /* Make sure we are running on kernel cr3 */ > > + SWITCH_TO_KERNEL_CR3 scratch_reg=%eax > > + > > xorl %edx, %edx # error code 0 > > movl %esp, %eax # pt_regs pointer > > > > The debug exception calls ret_from_exception on exit. If coming from > userspace, the C function prepare_exit_to_usermode() will be called. > With the PTI-32 code, it means that function will be called with the > entry stack instead of the task stack. This can be problematic as macro > like current won't work anymore.
This is not different from before, no? The debug handler already can be entered on entry stack before this patch-set.
Joerg
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