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| author | Thomas Gleixner <tglx@linutronix.de> | 2021-10-15 01:09:38 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-10-22 11:09:15 +0200 |
| commit | eda32f4f93b452c5fe3c352523e7f7cc085c8205 (patch) | |
| tree | 31af7db20335b0b0f50fbbb19e4b212abbb61245 /arch/x86/include | |
| parent | x86/fpu: Mop up xfeatures_mask_uabi() (diff) | |
| download | linux-eda32f4f93b452c5fe3c352523e7f7cc085c8205.tar.xz linux-eda32f4f93b452c5fe3c352523e7f7cc085c8205.zip | |
x86/fpu: Rework restore_regs_from_fpstate()
xfeatures_mask_fpstate() is no longer valid when dynamically enabled
features come into play.
Rework restore_regs_from_fpstate() so it takes a constant mask which will
then be applied against the maximum feature set so that the restore
operation brings all features which are not in the xsave buffer xfeature
bitmap into init state.
This ensures that if the previous task used a dynamically enabled feature
that the task which restores has all unused components properly initialized.
Cleanup the last user of xfeatures_mask_fpstate() as well and remove it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211014230739.461348278@linutronix.de
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/fpu/xstate.h | 27 |
1 files changed, 7 insertions, 20 deletions
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index 3c890b97f195..61ae396bc6e7 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -78,30 +78,17 @@ XFEATURE_MASK_INDEPENDENT | \ XFEATURE_MASK_SUPERVISOR_UNSUPPORTED) -static inline u64 xfeatures_mask_supervisor(void) -{ - return fpu_kernel_cfg.max_features & XFEATURE_MASK_SUPERVISOR_SUPPORTED; -} - /* - * The xfeatures which are restored by the kernel when returning to user - * mode. This is not necessarily the same as xfeatures_mask_uabi() as the - * kernel does not manage all XCR0 enabled features via xsave/xrstor as - * some of them have to be switched eagerly on context switch and exec(). + * The feature mask required to restore FPU state: + * - All user states which are not eagerly switched in switch_to()/exec() + * - The suporvisor states */ -static inline u64 xfeatures_mask_restore_user(void) -{ - return fpu_kernel_cfg.max_features & XFEATURE_MASK_USER_RESTORE; -} +#define XFEATURE_MASK_FPSTATE (XFEATURE_MASK_USER_RESTORE | \ + XFEATURE_MASK_SUPERVISOR_SUPPORTED) -/* - * Like xfeatures_mask_restore_user() but additionally restors the - * supported supervisor states. - */ -static inline u64 xfeatures_mask_fpstate(void) +static inline u64 xfeatures_mask_supervisor(void) { - return fpu_kernel_cfg.max_features & \ - (XFEATURE_MASK_USER_RESTORE | XFEATURE_MASK_SUPERVISOR_SUPPORTED); + return fpu_kernel_cfg.max_features & XFEATURE_MASK_SUPERVISOR_SUPPORTED; } static inline u64 xfeatures_mask_independent(void) |