[patch V2 38/52] x86/cpu: Write the default PKRU value when enabling PKE

Thomas Gleixner
2021-06-14T16:39:58Z

In preparation of making the PKRU management more independent from XSTATES,
write the default PKRU value into the hardware right after enabling PKRU in
CR4. This ensures that switch_to() and copy_thread() have the correct
setting for init task and the per CPU idle threads right away.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/cpu/common.c | 2 ++
1 file changed, 2 insertions(+)

--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -480,6 +480,8 @@ static __always_inline void setup_pku(st
}

cr4_set_bits(X86_CR4_PKE);
+ /* Load the default PKRU value */
+ pkru_write_default();
}

#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS