4.14-stable review patch. If anyone has any objections, please let me know.
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From: Ricardo Neri ricardo.neri-calderon@linux.intel.com
commit b0ce5b8c95c83a7b98c679b117e3d6ae6f97154b upstream.
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 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.
Suggested-by: Borislav Petkov bp@alien8.de Signed-off-by: Ricardo Neri ricardo.neri-calderon@linux.intel.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Borislav Petkov bp@suse.de Reviewed-by: Andy Lutomirski luto@kernel.org Cc: "Michael S. Tsirkin" mst@redhat.com Cc: Peter Zijlstra peterz@infradead.org Cc: Dave Hansen dave.hansen@linux.intel.com Cc: ricardo.neri@intel.com Cc: linux-mm@kvack.org Cc: Paul Gortmaker paul.gortmaker@windriver.com Cc: Huang Rui ray.huang@amd.com Cc: Shuah Khan shuah@kernel.org Cc: linux-arch@vger.kernel.org Cc: Jonathan Corbet corbet@lwn.net Cc: Jiri Slaby jslaby@suse.cz Cc: "Ravi V. Shankar" ravi.v.shankar@intel.com Cc: Denys Vlasenko dvlasenk@redhat.com Cc: Chris Metcalf cmetcalf@mellanox.com Cc: Brian Gerst brgerst@gmail.com Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Chen Yucong slaoub@gmail.com Cc: Vlastimil Babka vbabka@suse.cz Cc: Dave Hansen dave.hansen@intel.com Cc: Andy Lutomirski luto@amacapital.net Cc: Masami Hiramatsu mhiramat@kernel.org Cc: Paolo Bonzini pbonzini@redhat.com Cc: Andrew Morton akpm@linux-foundation.org Cc: Linus Torvalds torvalds@linux-foundation.org Link: https://lkml.kernel.org/r/1509135945-13762-3-git-send-email-ricardo.neri-cal... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/include/uapi/asm/processor-flags.h | 3 +++ arch/x86/kernel/head_32.S | 3 --- arch/x86/kernel/head_64.S | 3 --- 3 files changed, 3 insertions(+), 6 deletions(-)
--- a/arch/x86/include/uapi/asm/processor-flags.h +++ b/arch/x86/include/uapi/asm/processor-flags.h @@ -152,5 +152,8 @@ #define CX86_ARR_BASE 0xc4 #define CX86_RCR_BASE 0xdc
+#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 */ --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -212,9 +212,6 @@ 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
--- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -154,9 +154,6 @@ 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