Re: [tip:x86/smap] x86-32: Start out eflags and cr4 clean

2012-11-23 Thread H. Peter Anvin
On 11/23/2012 07:49 PM, Yuhong Bao wrote: + * Specifically, cr4 exists if and only if CPUID exists, + * which in turn exists if and only if EFLAGS.ID exists. This may be true for *Intel* 486 CPUs as VME was implemented at the same time as CPUID, but I am not sure that it is true for AMD 486

RE: [tip:x86/smap] x86-32: Start out eflags and cr4 clean

2012-11-23 Thread Yuhong Bao
> + * Specifically, cr4 exists if and only if CPUID exists, > + * which in turn exists if and only if EFLAGS.ID exists. This may be true for *Intel* 486 CPUs as VME was implemented at the same time as CPUID, but I am not sure that it is true for AMD 486 CPUs. Yuhong Bao

RE: [tip:x86/smap] x86-32: Start out eflags and cr4 clean

2012-11-23 Thread Yuhong Bao
+ * Specifically, cr4 exists if and only if CPUID exists, + * which in turn exists if and only if EFLAGS.ID exists. This may be true for *Intel* 486 CPUs as VME was implemented at the same time as CPUID, but I am not sure that it is true for AMD 486 CPUs. Yuhong Bao

Re: [tip:x86/smap] x86-32: Start out eflags and cr4 clean

2012-11-23 Thread H. Peter Anvin
On 11/23/2012 07:49 PM, Yuhong Bao wrote: + * Specifically, cr4 exists if and only if CPUID exists, + * which in turn exists if and only if EFLAGS.ID exists. This may be true for *Intel* 486 CPUs as VME was implemented at the same time as CPUID, but I am not sure that it is true for AMD 486