Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [patch v3 2/7] x86/smp: Dont access non-existing CPUID leaf | Date | Mon, 19 Jun 2023 19:15:01 +0200 |
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On Mon, Jun 19 2023 at 12:02, Limonciello, Mario wrote: > On 6/15/2023 3:33 PM, Thomas Gleixner wrote: >> From: Tony Battersby <tonyb@cybernetics.com> >> >> stop_this_cpu() tests CPUID leaf 0x8000001f::EAX unconditionally. CPUs >> return the content of the highest supported leaf when a non-existing leaf >> is read. So the result of the test is lottery except on AMD CPUs which >> support that leaf. >> >> While harmless it's incorrect and causes the conditional wbinvd() to be >> issued where not required. >> >> Check whether the leaf is supported before reading it. >> >> [ tglx: Adjusted changelog ] >> >> Fixes: 08f253ec3767 ("x86/cpu: Clear SME feature flag when not in use") > > Thanks for this fix. > This particular patch should probably also CC to stable.
It's pretty much all stable material.
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