Messages in this thread | | | From | Lai Jiangshan <> | Date | Fri, 18 Mar 2022 09:14:09 +0800 | Subject | Re: [PATCH] x86/sev: Add ENCODE_FRAME_POINTER after stack changed for #VC |
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On Fri, Mar 18, 2022 at 6:19 AM Josh Poimboeuf <jpoimboe@redhat.com> wrote: > > On Wed, Mar 16, 2022 at 12:16:12PM +0800, Lai Jiangshan wrote: > > From: Lai Jiangshan <jiangshan.ljs@antgroup.com> > > > > In idtentry_vc(), the real frame is changed after it switches to new > > stack, ENCODE_FRAME_POINTER should be called in case for unwinder. > > > > Cc: Joerg Roedel <jroedel@suse.de> > > Cc: Josh Poimboeuf <jpoimboe@redhat.com> > > Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com> > > --- > > arch/x86/entry/entry_64.S | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S > > index e20eabaa56b8..f99f2881ed83 100644 > > --- a/arch/x86/entry/entry_64.S > > +++ b/arch/x86/entry/entry_64.S > > @@ -540,6 +540,7 @@ SYM_CODE_START(\asmsym) > > call vc_switch_off_ist > > movq %rax, %rsp /* Switch to new stack */ > > > > + ENCODE_FRAME_POINTER > > UNWIND_HINT_REGS > > > > /* Update pt_regs */ > > Looks right to me. Any chance you have the ability to test this > scenario by unwinding from #VC with CONFIG_FRAME_POINTER? >
I don't have the hardware to test it. Actually, it was you to inspire me to find this in the conversation of my patchset when I tried to search all the code of switching of %rsp to see how ENCODE_FRAME_POINTER and UNWIND_HINT_REGS are used once more.
> -- > Josh >
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