diff options
| -rw-r--r-- | arch/x86/include/asm/fpu/xstate.h | 27 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/context.h | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 17 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 2 |
4 files changed, 23 insertions, 29 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) diff --git a/arch/x86/kernel/fpu/context.h b/arch/x86/kernel/fpu/context.h index f8f510519688..a06ebf315d83 100644 --- a/arch/x86/kernel/fpu/context.h +++ b/arch/x86/kernel/fpu/context.h @@ -61,8 +61,6 @@ static inline void fpregs_restore_userregs(void) return; if (!fpregs_state_valid(fpu, cpu)) { - u64 mask; - /* * This restores _all_ xstate which has not been * established yet. @@ -72,9 +70,7 @@ static inline void fpregs_restore_userregs(void) * flush_thread(). So it is excluded because it might be * not up to date in current->thread.fpu.xsave state. */ - mask = xfeatures_mask_restore_user() | - xfeatures_mask_supervisor(); - restore_fpregs_from_fpstate(fpu->fpstate, mask); + restore_fpregs_from_fpstate(fpu->fpstate, XFEATURE_MASK_FPSTATE); fpregs_activate(fpu); fpu->last_cpu = cpu; diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 5acc077cb9f1..0fb9defaba47 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -150,6 +150,17 @@ void restore_fpregs_from_fpstate(struct fpstate *fpstate, u64 mask) } if (use_xsave()) { + /* + * Restoring state always needs to modify all features + * which are in @mask even if the current task cannot use + * extended features. + * + * So fpstate->xfeatures cannot be used here, because then + * a feature for which the task has no permission but was + * used by the previous task would not go into init state. + */ + mask = fpu_kernel_cfg.max_features & mask; + os_xrstor(&fpstate->regs.xsave, mask); } else { if (use_fxsr()) @@ -161,7 +172,7 @@ void restore_fpregs_from_fpstate(struct fpstate *fpstate, u64 mask) void fpu_reset_from_exception_fixup(void) { - restore_fpregs_from_fpstate(&init_fpstate, xfeatures_mask_fpstate()); + restore_fpregs_from_fpstate(&init_fpstate, XFEATURE_MASK_FPSTATE); } #if IS_ENABLED(CONFIG_KVM) @@ -179,7 +190,7 @@ void fpu_swap_kvm_fpu(struct fpu *save, struct fpu *rstor, u64 restore_mask) } if (rstor) { - restore_mask &= xfeatures_mask_fpstate(); + restore_mask &= XFEATURE_MASK_FPSTATE; restore_fpregs_from_fpstate(rstor->fpstate, restore_mask); } @@ -518,7 +529,7 @@ void fpu__clear_user_states(struct fpu *fpu) } /* Reset user states in registers. */ - restore_fpregs_from_init_fpstate(xfeatures_mask_restore_user()); + restore_fpregs_from_init_fpstate(XFEATURE_MASK_USER_RESTORE); /* * Now all FPU registers have their desired values. Inform the FPU diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 9f92abd230db..cbba3812a160 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -344,7 +344,7 @@ static void __init print_xstate_offset_size(void) */ static __init void os_xrstor_booting(struct xregs_state *xstate) { - u64 mask = xfeatures_mask_fpstate(); + u64 mask = fpu_kernel_cfg.max_features & XFEATURE_MASK_FPSTATE; u32 lmask = mask; u32 hmask = mask >> 32; int err; |