Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 10 Aug 2023 14:51:22 +0200 | From | Borislav Petkov <> | Subject | Re: Hang when booting guest kernels compiled with clang after SRSO mitigations |
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On Thu, Aug 10, 2023 at 03:16:49AM -0700, Nathan Chancellor wrote: > Just to clarify, this is the guest kernel at -rc5 and the host kernel > with the SRSO mitigations applied? If so, that's the problem. The guest > kernel does not have to have the SRSO mitigations applied to see this > problem. Sorry I should have made that more clear! If not though, that's > interesting because I was running -rc5 on the host without issues.
Well, how do you even build CPU_SRSO with clang?
config CPU_SRSO bool "Mitigate speculative RAS overflow on AMD" depends on CPU_SUP_AMD && X86_64 && RETHUNK ^^^^^^^
config RETHUNK bool "Enable return-thunks" depends on RETPOLINE && CC_HAS_RETURN_THUNK ^^^^^^^^^^^^^^^^^^^
config CC_HAS_RETURN_THUNK def_bool $(cc-option,-mfunction-return=thunk-extern)
$ clang -mfunction-return=thunk-extern clang: error: unknown argument: '-mfunction-return=thunk-extern' clang: error: no input files
$ clang --version Debian clang version 14.0.6 Target: x86_64-pc-linux-gnu Thread model: posix InstalledDir: /usr/bin
Hmmm.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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