Re: [v3 PATCH 00/10] x86: Enable User-Mode Instruction Prevention
"H. Peter Anvin" <[email protected]> Wed, 25 Jan 2017 12:34:07 -0800
| Newsgroups | org.kernel.vger.linux-msdos,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
On 01/25/17 12:23, Ricardo Neri wrote: > * SMSW returns the value with which the CR0 register is programmed in > head_32/64.S at boot time. This is, the following bits are enabed: > CR0.0 for Protection Enable, CR.1 for Monitor Coprocessor, CR.4 for > Extension Type, which will always be 1 in recent processors with UMIP; > CR.5 for Numeric Error, CR0.16 for Write Protect, CR0.18 for Alignment > Mask. Additionally, in x86_64, CR0.31 for Paging is set. SMSW only returns CR0[15:0], so the reference here to CR0[31:16] seems odd. -hpa