From: Thomas Gleixner Date: Wed, 23 Jun 2021 12:02:10 +0000 (+0200) Subject: x86/cpu: Write the default PKRU value when enabling PKE X-Git-Tag: v5.14-rc1~52^2~23 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fa8c84b77a54bf3cf351c8b4b26a5aca27a14013;p=thirdparty%2Fkernel%2Flinux.git x86/cpu: Write the default PKRU value when enabling PKE 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 Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210623121455.622983906@linutronix.de --- diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index dbfb335ffac4e..ca668efa4c81e 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -480,6 +480,8 @@ static __always_inline void setup_pku(struct cpuinfo_x86 *c) } cr4_set_bits(X86_CR4_PKE); + /* Load the default PKRU value */ + pkru_write_default(); } #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS