Messages in this thread | | | Date | Thu, 25 Apr 2019 11:21:31 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH] x86/paravirt: Detect oversized patching bugs as they happen and BUG_ON() to avoid later crashes |
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On Thu, Apr 25, 2019 at 11:17:17AM +0200, Ingo Molnar wrote: > It basically means that we silently won't do any patching and the kernel > will crash later on in mysterious ways, because paravirt patching is > usually relied on.
That's OK. The compiler emits an indirect CALL/JMP to the pv_ops structure contents. That _should_ stay valid and function correctly at all times.
Not patching should at the very least cause a WARN with RETPOLINE kernels though, we hard rely on the patching actually working and writing at least a direct call.
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