x86/fpu: Remove fpu::state

mainline inclusion
from mainline-v5.16-rc1
commit 2f27b503
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I590ZC
CVE: NA

Intel-SIG: commit 2f27b503 x86/fpu: Remove fpu::state.

--------------------------------

All users converted. Remove it along with the sanity checks.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.765063318@linutronix.deSigned-off-by: NLin Wang <lin.x.wang@intel.com>

arch/x86/include/asm/fpu/types.h

@@ -352,20 +352,16 @@ struct fpu {
 	struct fpstate			*fpstate;
 
 	/*
-	 * @state:
+	 * @__fpstate:
 	 *
-	 * In-memory copy of all FPU registers that we save/restore
-	 * over context switches. If the task is using the FPU then
-	 * the registers in the FPU are more recent than this state
-	 * copy. If the task context-switches away then they get
-	 * saved here and represent the FPU state.
+	 * Initial in-memory storage for FPU registers which are saved in
+	 * context switch and when the kernel uses the FPU. The registers
+	 * are restored from this storage on return to user space if they
+	 * are not longer containing the tasks FPU register state.
 	 */
-	union {
 	struct fpstate			__fpstate;
-		union fpregs_state		state;
-	};
 	/*
-	 * WARNING: 'state' is dynamically-sized.  Do not put
+	 * WARNING: '__fpstate' is dynamically-sized.  Do not put
 	 * anything after it here.
 	 */
 };

arch/x86/kernel/fpu/init.c

@@ -184,10 +184,6 @@ static void __init fpu__init_task_struct_size(void)
 	CHECK_MEMBER_AT_END_OF(struct thread_struct, fpu);
 	CHECK_MEMBER_AT_END_OF(struct task_struct, thread);
 
-	BUILD_BUG_ON(sizeof(struct fpstate) != sizeof(union fpregs_state));
-	BUILD_BUG_ON(offsetof(struct thread_struct, fpu.state) !=
-		     offsetof(struct thread_struct, fpu.__fpstate));
-
 	arch_task_struct_size = task_size;
 }