Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 31 Jan 2023 11:50:04 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH] x86/tdx: Do not corrupt frame-pointer in __tdx_hypercall() |
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On Tue, Jan 31, 2023 at 09:32:37AM +0100, Peter Zijlstra wrote: > 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
Oops, just noticed a typo. s/in/is/
> > __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. > > > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > > Fixes: c30c4b2555ba ("x86/tdx: Refactor __tdx_hypercall() to allow pass down more arguments") > > Link: https://lore.kernel.org/all/202301290255.buUBs99R-lkp@intel.com > > Reported-by: kernel test robot <lkp@intel.com> > > Cc: Peter Zijlstra <peterz@infradead.org> > > --- > > > > The patch is against tip/x86/tdx. tip/sched/core removes > > TDX_HCALL_ISSUE_STI. The trird hunk of the patch is not relevant > > after that. > > Right, this should work. But it does leave me wondering, should we > perhaps strive to completely remove the flags thing and move to > __tdx_hypercall() and __tdx_hypercall_ret() or something? That is, > simply have two different functions, one with and one without return > data. > > It should be trivial to generate that without actual code duplication.
Yeah, that's doable. I will give it a try. I guess on top this one (plus sched/core changes) should be.
-- Kiryl Shutsemau / Kirill A. Shutemov
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