Messages in this thread Patch in this message |  | | From | Ricardo Neri <> | Subject | [PATCH v8 02/28] x86/boot: Relocate definition of the initial state of CR0 | Date | Fri, 18 Aug 2017 17:27:43 -0700 |
| |
Both head_32.S and head_64.S utilize the same value to initialize the control register CR0. Also, other parts of the kernel might want to access to this initial definition (e.g., emulation code for User-Mode Instruction Prevention uses this state to provide a sane dummy value for CR0 when emulating the smsw instruction). Thus, relocate this definition to a header file from which it can be conveniently accessed.
Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> --- arch/x86/include/uapi/asm/processor-flags.h | 6 ++++++ arch/x86/kernel/head_32.S | 3 --- arch/x86/kernel/head_64.S | 3 --- 3 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/uapi/asm/processor-flags.h b/arch/x86/include/uapi/asm/processor-flags.h index 185f3d10c194..aae1f2aa7563 100644 --- a/arch/x86/include/uapi/asm/processor-flags.h +++ b/arch/x86/include/uapi/asm/processor-flags.h @@ -151,5 +151,11 @@ #define CX86_ARR_BASE 0xc4 #define CX86_RCR_BASE 0xdc +/* + * Initial state of CR0 for head_32/64.S + */ +#define CR0_STATE (X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | \ + X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | \ + X86_CR0_PG) #endif /* _UAPI_ASM_X86_PROCESSOR_FLAGS_H */ diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index 0332664eb158..f64059835863 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -213,9 +213,6 @@ ENTRY(startup_32_smp) #endif .Ldefault_entry: -#define CR0_STATE (X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | \ - X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | \ - X86_CR0_PG) movl $(CR0_STATE & ~X86_CR0_PG),%eax movl %eax,%cr0 diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 513cbb012ecc..5e1bfdd86b5b 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -149,9 +149,6 @@ ENTRY(secondary_startup_64) 1: wrmsr /* Make changes effective */ /* Setup cr0 */ -#define CR0_STATE (X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | \ - X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | \ - X86_CR0_PG) movl $CR0_STATE, %eax /* Make changes effective */ movq %rax, %cr0 -- 2.13.0
|  |