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

Pull exception table generation updates from Ingo Molnar:
 "The biggest change here is to allow the build-time sorting of the
  exception table, to speed up booting.  This is achieved by the
  architecture enabling BUILDTIME_EXTABLE_SORT.  This option is enabled
  for x86 and MIPS currently.

  On x86 a number of fixes and changes were needed to allow build-time
  sorting of the exception table, in particular a relocation invariant
  exception table format was needed.  This required the abstracting out
  of exception table protocol and the removal of 20 years of accumulated
  assumptions about the x86 exception table format.

  While at it, this tree also cleans up various other aspects of
  exception handling, such as early(er) exception handling for
  rdmsr_safe() et al.

  All in one, as the result of these changes the x86 exception code is
  now pretty nice and modern.  As an added bonus any regressions in this
  code will be early and violent crashes, so if you see any of those,
  you'll know whom to blame!"

Fix up trivial conflicts in arch/{mips,x86}/Kconfig files due to nearby
modifications of other core architecture options.

* 'x86-extable-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits)
  Revert "x86, extable: Disable presorted exception table for now"
  scripts/sortextable: Handle relative entries, and other cleanups
  x86, extable: Switch to relative exception table entries
  x86, extable: Disable presorted exception table for now
  x86, extable: Add _ASM_EXTABLE_EX() macro
  x86, extable: Remove open-coded exception table entries in arch/x86/ia32/ia32entry.S
  x86, extable: Remove open-coded exception table entries in arch/x86/include/asm/xsave.h
  x86, extable: Remove open-coded exception table entries in arch/x86/include/asm/kvm_host.h
  x86, extable: Remove the now-unused __ASM_EX_SEC macros
  x86, extable: Remove open-coded exception table entries in arch/x86/xen/xen-asm_32.S
  x86, extable: Remove open-coded exception table entries in arch/x86/um/checksum_32.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/usercopy_32.c
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/putuser.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/getuser.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/csum-copy_64.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/copy_user_nocache_64.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/copy_user_64.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/checksum_32.S
  x86, extable: Remove open-coded exception table entries in arch/x86/kernel/test_rodata.c
  x86, extable: Remove open-coded exception table entries in arch/x86/kernel/entry_64.S
  ...

1 files changed, 59 insertions, 21 deletions

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 40f4eb3766d1..7a40f2447321 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -19,12 +19,15 @@
 #include <asm/cache.h>
 #include <asm/processor-flags.h>
 #include <asm/percpu.h>
+#include <asm/nops.h>
 
 #ifdef CONFIG_PARAVIRT
 #include <asm/asm-offsets.h>
 #include <asm/paravirt.h>
+#define GET_CR2_INTO(reg) GET_CR2_INTO_RAX ; movq %rax, reg
 #else
-#define GET_CR2_INTO_RCX movq %cr2, %rcx
+#define GET_CR2_INTO(reg) movq %cr2, reg
+#define INTERRUPT_RETURN iretq
 #endif
 
 /* we are not able to switch in one step to the final KERNEL ADDRESS SPACE
@@ -270,36 +273,56 @@ bad_address:
 	jmp bad_address
 
 	.section ".init.text","ax"
-#ifdef CONFIG_EARLY_PRINTK
 	.globl early_idt_handlers
 early_idt_handlers:
+	# 104(%rsp) %rflags
+	#  96(%rsp) %cs
+	#  88(%rsp) %rip
+	#  80(%rsp) error code
 	i = 0
 	.rept NUM_EXCEPTION_VECTORS
-	movl $i, %esi
+	.if (EXCEPTION_ERRCODE_MASK >> i) & 1
+	ASM_NOP2
+	.else
+	pushq $0		# Dummy error code, to make stack frame uniform
+	.endif
+	pushq $i		# 72(%rsp) Vector number
 	jmp early_idt_handler
 	i = i + 1
 	.endr
-#endif
 
 ENTRY(early_idt_handler)
-#ifdef CONFIG_EARLY_PRINTK
+	cld
+
 	cmpl $2,early_recursion_flag(%rip)
 	jz  1f
 	incl early_recursion_flag(%rip)
-	GET_CR2_INTO_RCX
-	movq %rcx,%r9
-	xorl %r8d,%r8d		# zero for error code
-	movl %esi,%ecx		# get vector number
-	# Test %ecx against mask of vectors that push error code.
-	cmpl $31,%ecx
-	ja 0f
-	movl $1,%eax
-	salq %cl,%rax
-	testl $0x27d00,%eax
-	je 0f
-	popq %r8		# get error code
-0:	movq 0(%rsp),%rcx	# get ip
-	movq 8(%rsp),%rdx	# get cs
+
+	pushq %rax		# 64(%rsp)
+	pushq %rcx		# 56(%rsp)
+	pushq %rdx		# 48(%rsp)
+	pushq %rsi		# 40(%rsp)
+	pushq %rdi		# 32(%rsp)
+	pushq %r8		# 24(%rsp)
+	pushq %r9		# 16(%rsp)
+	pushq %r10		#  8(%rsp)
+	pushq %r11		#  0(%rsp)
+
+	cmpl $__KERNEL_CS,96(%rsp)
+	jne 10f
+
+	leaq 88(%rsp),%rdi	# Pointer to %rip
+	call early_fixup_exception
+	andl %eax,%eax
+	jnz 20f			# Found an exception entry
+
+10:
+#ifdef CONFIG_EARLY_PRINTK
+	GET_CR2_INTO(%r9)	# can clobber any volatile register if pv
+	movl 80(%rsp),%r8d	# error code
+	movl 72(%rsp),%esi	# vector number
+	movl 96(%rsp),%edx	# %cs
+	movq 88(%rsp),%rcx	# %rip
 	xorl %eax,%eax
 	leaq early_idt_msg(%rip),%rdi
 	call early_printk
@@ -308,17 +331,32 @@ ENTRY(early_idt_handler)
 	call dump_stack
 #ifdef CONFIG_KALLSYMS	
 	leaq early_idt_ripmsg(%rip),%rdi
-	movq 0(%rsp),%rsi	# get rip again
+	movq 40(%rsp),%rsi	# %rip again
 	call __print_symbol
 #endif
 #endif /* EARLY_PRINTK */
 1:	hlt
 	jmp 1b
 
-#ifdef CONFIG_EARLY_PRINTK
+20:	# Exception table entry found
+	popq %r11
+	popq %r10
+	popq %r9
+	popq %r8
+	popq %rdi
+	popq %rsi
+	popq %rdx
+	popq %rcx
+	popq %rax
+	addq $16,%rsp		# drop vector number and error code
+	decl early_recursion_flag(%rip)
+	INTERRUPT_RETURN
+
+	.balign 4
 early_recursion_flag:
 	.long 0
 
+#ifdef CONFIG_EARLY_PRINTK
 early_idt_msg:
 	.asciz "PANIC: early exception %02lx rip %lx:%lx error %lx cr2 %lx\n"
 early_idt_ripmsg: