Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Peter Anvin:

 - Three EFI-related fixes

 - Two early memory initialization fixes

 - build fix for older binutils

 - fix for an eager FPU performance regression -- currently we don't
   allow the use of the FPU at interrupt time *at all* in eager mode,
   which is clearly wrong.

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Allow FPU to be used at interrupt time even with eagerfpu
  x86, crc32-pclmul: Fix build with older binutils
  x86-64, init: Fix a possible wraparound bug in switchover in head_64.S
  x86, range: fix missing merge during add range
  x86, efi: initial the local variable of DataSize to zero
  efivar: fix oops in efivar_update_sysfs_entries() caused by memory reuse
  efivarfs: Never return ENOENT from firmware again

2 files changed, 9 insertions, 11 deletions

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 08f7e80..321d65e 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -115,8 +115,10 @@ startup_64:
 	movq	%rdi, %rax
 	shrq	$PUD_SHIFT, %rax
 	andl	$(PTRS_PER_PUD-1), %eax
-	movq	%rdx, (4096+0)(%rbx,%rax,8)
-	movq	%rdx, (4096+8)(%rbx,%rax,8)
+	movq	%rdx, 4096(%rbx,%rax,8)
+	incl	%eax
+	andl	$(PTRS_PER_PUD-1), %eax
+	movq	%rdx, 4096(%rbx,%rax,8)
 
 	addq	$8192, %rbx
 	movq	%rdi, %rax
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 245a71d..cb33909 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -22,23 +22,19 @@
 /*
  * Were we in an interrupt that interrupted kernel mode?
  *
- * For now, with eagerfpu we will return interrupted kernel FPU
- * state as not-idle. TBD: Ideally we can change the return value
- * to something like __thread_has_fpu(current). But we need to
- * be careful of doing __thread_clear_has_fpu() before saving
- * the FPU etc for supporting nested uses etc. For now, take
- * the simple route!
- *
  * On others, we can do a kernel_fpu_begin/end() pair *ONLY* if that
  * pair does nothing at all: the thread must not have fpu (so
  * that we don't try to save the FPU state), and TS must
  * be set (so that the clts/stts pair does nothing that is
  * visible in the interrupted kernel thread).
+ *
+ * Except for the eagerfpu case when we return 1 unless we've already
+ * been eager and saved the state in kernel_fpu_begin().
  */
 static inline bool interrupted_kernel_fpu_idle(void)
 {
 	if (use_eager_fpu())
-		return 0;
+		return __thread_has_fpu(current);
 
 	return !__thread_has_fpu(current) &&
 		(read_cr0() & X86_CR0_TS);
@@ -78,8 +74,8 @@ void __kernel_fpu_begin(void)
 	struct task_struct *me = current;
 
 	if (__thread_has_fpu(me)) {
-		__save_init_fpu(me);
 		__thread_clear_has_fpu(me);
+		__save_init_fpu(me);
 		/* We do 'stts()' in __kernel_fpu_end() */
 	} else if (!use_eager_fpu()) {
 		this_cpu_write(fpu_owner_task, NULL);