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| author | H. Peter Anvin (Intel) <hpa@zytor.com> | 2023-12-05 02:50:00 -0800 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-01-31 22:00:38 +0100 |
| commit | ff45746fbf005f96e42bea466698e3fdbf926013 (patch) | |
| tree | 996ccca80c84a3e2000681b4676f3fb7a844d83c | |
| parent | cd19bab825bda5bb192ef1d22e67d069daf2efb8 (diff) | |
| download | lwn-ff45746fbf005f96e42bea466698e3fdbf926013.tar.gz lwn-ff45746fbf005f96e42bea466698e3fdbf926013.zip | |
x86/cpu: Add X86_CR4_FRED macro
Add X86_CR4_FRED macro for the FRED bit in %cr4. This bit must not be
changed after initialization, so add it to the pinned CR4 bits.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-12-xin3.li@intel.com
| -rw-r--r-- | arch/x86/include/uapi/asm/processor-flags.h | 7 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 5 |
2 files changed, 9 insertions, 3 deletions
diff --git a/arch/x86/include/uapi/asm/processor-flags.h b/arch/x86/include/uapi/asm/processor-flags.h index d898432947ff..f1a4adc78272 100644 --- a/arch/x86/include/uapi/asm/processor-flags.h +++ b/arch/x86/include/uapi/asm/processor-flags.h @@ -139,6 +139,13 @@ #define X86_CR4_LAM_SUP_BIT 28 /* LAM for supervisor pointers */ #define X86_CR4_LAM_SUP _BITUL(X86_CR4_LAM_SUP_BIT) +#ifdef __x86_64__ +#define X86_CR4_FRED_BIT 32 /* enable FRED kernel entry */ +#define X86_CR4_FRED _BITUL(X86_CR4_FRED_BIT) +#else +#define X86_CR4_FRED (0) +#endif + /* * x86-64 Task Priority Register, CR8 */ diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 0b97bcde70c6..c3a175770df0 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -382,9 +382,8 @@ out: } /* These bits should not change their value after CPU init is finished. */ -static const unsigned long cr4_pinned_mask = - X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_UMIP | - X86_CR4_FSGSBASE | X86_CR4_CET; +static const unsigned long cr4_pinned_mask = X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_UMIP | + X86_CR4_FSGSBASE | X86_CR4_CET | X86_CR4_FRED; static DEFINE_STATIC_KEY_FALSE_RO(cr_pinning); static unsigned long cr4_pinned_bits __ro_after_init; |