Messages in this thread | | | Date | Tue, 31 Jan 2023 09:34:12 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] x86/tdx: Do not corrupt frame-pointer in __tdx_hypercall() |
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On Mon, Jan 30, 2023 at 04:53:54PM +0300, Kirill A. Shutemov wrote: > If compiled with CONFIG_FRAME_POINTER=y, objtool in not happy that > __tdx_hypercall() messes up RBP. > > objtool: __tdx_hypercall+0x7f: return with modified stack frame > > Rework the function to store TDX_HCALL_ flags on stack instead of RBP.
Also, on IRC you mentioned that per TDX spec, BP is a valid argument register too and you were going to raise this and get it fixed, TDX hypercalls must not use BP to pass data.
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