Messages in this thread | | | Subject | Re: [PATCH v8 06/11] x86/traps: Add #VE support for TDX guest | From | "Kuppuswamy, Sathyanarayanan" <> | Date | Thu, 7 Oct 2021 10:22:16 -0700 |
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On 10/7/21 10:06 AM, Borislav Petkov wrote: > Same question as before - why do you need to clear this @out thing above > when __tdx_module_call() will overwrite it?
Now checking again, I think we don't to initialize the @out pointer. I will fix this in call cases.
But for tdx_get_ve_info() case, we are updating the @ve pointer without checking the tdcall return value and __tdx_module_call() will update the @out only if tdcall is successful. Currently due to @out=0 initialization, this logic does not cause any issue. But to properly fix it, I need to check for tdcall return value before updating the @ve value.
> > What you should do instead is check that @ve pointer which you get > passed in - it might be NULL.
Current use case of tdx_get_ve_info() can never be NULL. But if you want to add this check for possible future issues, I can do it.
arch/x86/kernel/traps.c:1205: ret = tdx_get_ve_info(&ve); arch/x86/kernel/tdx.c:945: if (tdx_get_ve_info(&ve))
-- Sathyanarayanan Kuppuswamy Linux Kernel Developer
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