Messages in this thread | | | Date | Wed, 2 Mar 2016 18:50:21 -0800 | Subject | Re: [RFC PATCH] x86: Make sure verify_cpu has a good stack | From | Yinghai Lu <> |
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On Wed, Mar 2, 2016 at 5:00 PM, Yinghai Lu <yinghai@kernel.org> wrote: > On Wed, Mar 2, 2016 at 4:13 PM, Yinghai Lu <yinghai@kernel.org> wrote: >> On Wed, Mar 2, 2016 at 2:32 PM, H. Peter Anvin <hpa@zytor.com> wrote: >>> >>> I'm trying to think of any reason why we couldn't simply have a symbol at the top of the initial stack? Then a simple leaq would suffice; this is for the BSP after all. >> >> Why do we need to call verify_cpu in arch/x86/kernel/head_64.S aka the >> vmlinux again ? >> >> Is that already called in arch/x86/boot/compressed/head_64.S? > > that calling is from startup_32, so may add another calling in startup_64, > so can avoid calling from arch/x86/kernel/head_64.S >
at the same time, the "call verify_cpu" in arch/x86/kernel/head_64.s::secondary_startup_64() is not needed. As APs already go through arch/x86/realmode/rm/trampoline_64.S::trampoline_start(), and it already call verify_cpu in 16bit mode.
Thanks
Yinghai
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