Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

On Wed, Nov 30, 2016 at 5:18 AM, One Thousand Gnomes wrote: >> Rather than trying to work around these issues, just have the kernel >> fail loudly if it's running on a CPUID-less 486, doesn't have CPUID, >> and doesn't have CONFIG_M486 set. > > NAK > > This still

Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

On Wed, Nov 30, 2016 at 5:18 AM, One Thousand Gnomes wrote: >> Rather than trying to work around these issues, just have the kernel >> fail loudly if it's running on a CPUID-less 486, doesn't have CPUID, >> and doesn't have CONFIG_M486 set. > > NAK > > This still breaks the Geode at the very

Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

> Rather than trying to work around these issues, just have the kernel > fail loudly if it's running on a CPUID-less 486, doesn't have CPUID, > and doesn't have CONFIG_M486 set. NAK This still breaks the Geode at the very least and I think the ELAN and some of the other older socket 7 devices.

Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

> Rather than trying to work around these issues, just have the kernel > fail loudly if it's running on a CPUID-less 486, doesn't have CPUID, > and doesn't have CONFIG_M486 set. NAK This still breaks the Geode at the very least and I think the ELAN and some of the other older socket 7 devices.

Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

On Sun, Nov 20, 2016 at 05:34:43PM -0200, Henrique de Moraes Holschuh wrote: > On Sun, 20 Nov 2016, Borislav Petkov wrote: > > We will have set (or not) the X86_FEATURE_CPUID bit at > > early_identify_cpu() time. Looking at the code, we do call sync_core() > > pretty early. :-\ > > Hmm, watch out

Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

On Sun, Nov 20, 2016 at 05:34:43PM -0200, Henrique de Moraes Holschuh wrote: > On Sun, 20 Nov 2016, Borislav Petkov wrote: > > We will have set (or not) the X86_FEATURE_CPUID bit at > > early_identify_cpu() time. Looking at the code, we do call sync_core() > > pretty early. :-\ > > Hmm, watch out

Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

On Sun, 20 Nov 2016, Borislav Petkov wrote: > We will have set (or not) the X86_FEATURE_CPUID bit at > early_identify_cpu() time. Looking at the code, we do call sync_core() > pretty early. :-\ Hmm, watch out for the early microcode update driver for Intel processors should something get changed

Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

On Sun, 20 Nov 2016, Borislav Petkov wrote: > We will have set (or not) the X86_FEATURE_CPUID bit at > early_identify_cpu() time. Looking at the code, we do call sync_core() > pretty early. :-\ Hmm, watch out for the early microcode update driver for Intel processors should something get changed

Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

On Sun, Nov 20, 2016 at 08:22:25AM -0800, Andy Lutomirski wrote: > This makes me nervous: don't some CPUs actually need the cpuid > instruction when patching alternatives? Nope, we use boot_cpu_has() in apply_alternatives() if that is what you mean. > And with this approach, we won't have the

Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

On Sun, Nov 20, 2016 at 08:22:25AM -0800, Andy Lutomirski wrote: > This makes me nervous: don't some CPUs actually need the cpuid > instruction when patching alternatives? Nope, we use boot_cpu_has() in apply_alternatives() if that is what you mean. > And with this approach, we won't have the

Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

On Nov 20, 2016 3:19 AM, "Borislav Petkov" wrote: > > On Sat, Nov 19, 2016 at 03:37:30PM -0800, Andy Lutomirski wrote: > > Linux will have all kinds of sporadic problems on systems that don't > > have the CPUID instruction unless CONFIG_M486=y. In particular, > > sync_core() will

Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

On Nov 20, 2016 3:19 AM, "Borislav Petkov" wrote: > > On Sat, Nov 19, 2016 at 03:37:30PM -0800, Andy Lutomirski wrote: > > Linux will have all kinds of sporadic problems on systems that don't > > have the CPUID instruction unless CONFIG_M486=y. In particular, > > sync_core() will explode. > >

Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

On Sat, Nov 19, 2016 at 03:37:30PM -0800, Andy Lutomirski wrote: > Linux will have all kinds of sporadic problems on systems that don't > have the CPUID instruction unless CONFIG_M486=y. In particular, > sync_core() will explode. Btw, I think we should do something like this, in addition: ---

Re: [PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

On Sat, Nov 19, 2016 at 03:37:30PM -0800, Andy Lutomirski wrote: > Linux will have all kinds of sporadic problems on systems that don't > have the CPUID instruction unless CONFIG_M486=y. In particular, > sync_core() will explode. Btw, I think we should do something like this, in addition: ---

[PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

Linux will have all kinds of sporadic problems on systems that don't have the CPUID instruction unless CONFIG_M486=y. In particular, sync_core() will explode. I believe that these kernels had a better chance of working before commit 05fb3c199bb0 ("x86/boot: Initialize FPU and X86_FEATURE_ALWAYS

[PATCH] x86/boot: Fail the boot if !M486 and CPUID is missing

Linux will have all kinds of sporadic problems on systems that don't have the CPUID instruction unless CONFIG_M486=y. In particular, sync_core() will explode. I believe that these kernels had a better chance of working before commit 05fb3c199bb0 ("x86/boot: Initialize FPU and X86_FEATURE_ALWAYS