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, 129 insertions, 94 deletions

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index ce0be7c..463c979 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -21,6 +21,7 @@
 #include <asm/msr-index.h>
 #include <asm/cpufeature.h>
 #include <asm/percpu.h>
+#include <asm/nops.h>
 
 /* Physical address */
 #define pa(X) ((X) - __PAGE_OFFSET)
@@ -363,28 +364,23 @@ default_entry:
 	pushl $0
 	popfl
 
-#ifdef CONFIG_SMP
-	cmpb $0, ready
-	jnz checkCPUtype
-#endif /* CONFIG_SMP */
-
 /*
  * start system 32-bit setup. We need to re-do some of the things done
  * in 16-bit mode for the "real" operations.
  */
-	call setup_idt
-
-checkCPUtype:
-
-	movl $-1,X86_CPUID		#  -1 for no CPUID initially
-
+	movl setup_once_ref,%eax
+	andl %eax,%eax
+	jz 1f				# Did we do this already?
+	call *%eax
+1:
+	
 /* check if it is 486 or 386. */
 /*
  * XXX - this does a lot of unnecessary setup.  Alignment checks don't
  * apply at our cpl of 0 and the stack ought to be aligned already, and
  * we don't need to preserve eflags.
  */
-
+	movl $-1,X86_CPUID	# -1 for no CPUID initially
 	movb $3,X86		# at least 386
 	pushfl			# push EFLAGS
 	popl %eax		# get EFLAGS
@@ -450,21 +446,6 @@ is386:	movl $2,%ecx		# set MP
 	movl $(__KERNEL_PERCPU), %eax
 	movl %eax,%fs			# set this cpu's percpu
 
-#ifdef CONFIG_CC_STACKPROTECTOR
-	/*
-	 * The linker can't handle this by relocation.  Manually set
-	 * base address in stack canary segment descriptor.
-	 */
-	cmpb $0,ready
-	jne 1f
-	movl $gdt_page,%eax
-	movl $stack_canary,%ecx
-	movw %cx, 8 * GDT_ENTRY_STACK_CANARY + 2(%eax)
-	shrl $16, %ecx
-	movb %cl, 8 * GDT_ENTRY_STACK_CANARY + 4(%eax)
-	movb %ch, 8 * GDT_ENTRY_STACK_CANARY + 7(%eax)
-1:
-#endif
 	movl $(__KERNEL_STACK_CANARY),%eax
 	movl %eax,%gs
 
@@ -473,7 +454,6 @@ is386:	movl $2,%ecx		# set MP
 
 	cld			# gcc2 wants the direction flag cleared at all times
 	pushl $0		# fake return address for unwinder
-	movb $1, ready
 	jmp *(initial_code)
 
 /*
@@ -495,81 +475,122 @@ check_x87:
 	.byte 0xDB,0xE4		/* fsetpm for 287, ignored by 387 */
 	ret
 
+	
+#include "verify_cpu.S"
+
 /*
- *  setup_idt
+ *  setup_once
  *
- *  sets up a idt with 256 entries pointing to
- *  ignore_int, interrupt gates. It doesn't actually load
- *  idt - that can be done only after paging has been enabled
- *  and the kernel moved to PAGE_OFFSET. Interrupts
- *  are enabled elsewhere, when we can be relatively
- *  sure everything is ok.
+ *  The setup work we only want to run on the BSP.
  *
  *  Warning: %esi is live across this function.
  */
-setup_idt:
-	lea ignore_int,%edx
-	movl $(__KERNEL_CS << 16),%eax
-	movw %dx,%ax		/* selector = 0x0010 = cs */
-	movw $0x8E00,%dx	/* interrupt gate - dpl=0, present */
+__INIT
+setup_once:
+	/*
+	 * Set up a idt with 256 entries pointing to ignore_int,
+	 * interrupt gates. It doesn't actually load idt - that needs
+	 * to be done on each CPU. Interrupts are enabled elsewhere,
+	 * when we can be relatively sure everything is ok.
+	 */
 
-	lea idt_table,%edi
-	mov $256,%ecx
-rp_sidt:
+	movl $idt_table,%edi
+	movl $early_idt_handlers,%eax
+	movl $NUM_EXCEPTION_VECTORS,%ecx
+1:
 	movl %eax,(%edi)
-	movl %edx,4(%edi)
+	movl %eax,4(%edi)
+	/* interrupt gate, dpl=0, present */
+	movl $(0x8E000000 + __KERNEL_CS),2(%edi)
+	addl $9,%eax
 	addl $8,%edi
-	dec %ecx
-	jne rp_sidt
+	loop 1b
 
-.macro	set_early_handler handler,trapno
-	lea \handler,%edx
+	movl $256 - NUM_EXCEPTION_VECTORS,%ecx
+	movl $ignore_int,%edx
 	movl $(__KERNEL_CS << 16),%eax
-	movw %dx,%ax
+	movw %dx,%ax		/* selector = 0x0010 = cs */
 	movw $0x8E00,%dx	/* interrupt gate - dpl=0, present */
-	lea idt_table,%edi
-	movl %eax,8*\trapno(%edi)
-	movl %edx,8*\trapno+4(%edi)
-.endm
+2:
+	movl %eax,(%edi)
+	movl %edx,4(%edi)
+	addl $8,%edi
+	loop 2b
 
-	set_early_handler handler=early_divide_err,trapno=0
-	set_early_handler handler=early_illegal_opcode,trapno=6
-	set_early_handler handler=early_protection_fault,trapno=13
-	set_early_handler handler=early_page_fault,trapno=14
+#ifdef CONFIG_CC_STACKPROTECTOR
+	/*
+	 * Configure the stack canary. The linker can't handle this by
+	 * relocation.  Manually set base address in stack canary
+	 * segment descriptor.
+	 */
+	movl $gdt_page,%eax
+	movl $stack_canary,%ecx
+	movw %cx, 8 * GDT_ENTRY_STACK_CANARY + 2(%eax)
+	shrl $16, %ecx
+	movb %cl, 8 * GDT_ENTRY_STACK_CANARY + 4(%eax)
+	movb %ch, 8 * GDT_ENTRY_STACK_CANARY + 7(%eax)
+#endif
 
+	andl $0,setup_once_ref	/* Once is enough, thanks */
 	ret
 
-early_divide_err:
-	xor %edx,%edx
-	pushl $0	/* fake errcode */
-	jmp early_fault
+ENTRY(early_idt_handlers)
+	# 36(%esp) %eflags
+	# 32(%esp) %cs
+	# 28(%esp) %eip
+	# 24(%rsp) error code
+	i = 0
+	.rept NUM_EXCEPTION_VECTORS
+	.if (EXCEPTION_ERRCODE_MASK >> i) & 1
+	ASM_NOP2
+	.else
+	pushl $0		# Dummy error code, to make stack frame uniform
+	.endif
+	pushl $i		# 20(%esp) Vector number
+	jmp early_idt_handler
+	i = i + 1
+	.endr
+ENDPROC(early_idt_handlers)
+	
+	/* This is global to keep gas from relaxing the jumps */
+ENTRY(early_idt_handler)
+	cld
+	cmpl $2,%ss:early_recursion_flag
+	je hlt_loop
+	incl %ss:early_recursion_flag
 
-early_illegal_opcode:
-	movl $6,%edx
-	pushl $0	/* fake errcode */
-	jmp early_fault
+	push %eax		# 16(%esp)
+	push %ecx		# 12(%esp)
+	push %edx		#  8(%esp)
+	push %ds		#  4(%esp)
+	push %es		#  0(%esp)
+	movl $(__KERNEL_DS),%eax
+	movl %eax,%ds
+	movl %eax,%es
 
-early_protection_fault:
-	movl $13,%edx
-	jmp early_fault
+	cmpl $(__KERNEL_CS),32(%esp)
+	jne 10f
 
-early_page_fault:
-	movl $14,%edx
-	jmp early_fault
+	leal 28(%esp),%eax	# Pointer to %eip
+	call early_fixup_exception
+	andl %eax,%eax
+	jnz ex_entry		/* found an exception entry */
 
-early_fault:
-	cld
+10:
 #ifdef CONFIG_PRINTK
-	pusha
-	movl $(__KERNEL_DS),%eax
-	movl %eax,%ds
-	movl %eax,%es
-	cmpl $2,early_recursion_flag
-	je hlt_loop
-	incl early_recursion_flag
+	xorl %eax,%eax
+	movw %ax,2(%esp)	/* clean up the segment values on some cpus */
+	movw %ax,6(%esp)
+	movw %ax,34(%esp)
+	leal  40(%esp),%eax
+	pushl %eax		/* %esp before the exception */
+	pushl %ebx
+	pushl %ebp
+	pushl %esi
+	pushl %edi
 	movl %cr2,%eax
 	pushl %eax
-	pushl %edx		/* trapno */
+	pushl (20+6*4)(%esp)	/* trapno */
 	pushl $fault_msg
 	call printk
 #endif
@@ -578,6 +599,17 @@ hlt_loop:
 	hlt
 	jmp hlt_loop
 
+ex_entry:
+	pop %es
+	pop %ds
+	pop %edx
+	pop %ecx
+	pop %eax
+	addl $8,%esp		/* drop vector number and error code */
+	decl %ss:early_recursion_flag
+	iret
+ENDPROC(early_idt_handler)
+
 /* This is the default interrupt "handler" :-) */
 	ALIGN
 ignore_int:
@@ -611,13 +643,18 @@ ignore_int:
 	popl %eax
 #endif
 	iret
+ENDPROC(ignore_int)
+__INITDATA
+	.align 4
+early_recursion_flag:
+	.long 0
 
-#include "verify_cpu.S"
-
-	__REFDATA
-.align 4
+__REFDATA
+	.align 4
 ENTRY(initial_code)
 	.long i386_start_kernel
+ENTRY(setup_once_ref)
+	.long setup_once
 
 /*
  * BSS section
@@ -670,22 +707,19 @@ ENTRY(initial_page_table)
 ENTRY(stack_start)
 	.long init_thread_union+THREAD_SIZE
 
-early_recursion_flag:
-	.long 0
-
-ready:	.byte 0
-
+__INITRODATA
 int_msg:
 	.asciz "Unknown interrupt or fault at: %p %p %p\n"
 
 fault_msg:
 /* fault info: */
 	.ascii "BUG: Int %d: CR2 %p\n"
-/* pusha regs: */
-	.ascii "     EDI %p  ESI %p  EBP %p  ESP %p\n"
-	.ascii "     EBX %p  EDX %p  ECX %p  EAX %p\n"
+/* regs pushed in early_idt_handler: */
+	.ascii "     EDI %p  ESI %p  EBP %p  EBX %p\n"
+	.ascii "     ESP %p   ES %p   DS %p\n"
+	.ascii "     EDX %p  ECX %p  EAX %p\n"
 /* fault frame: */
-	.ascii "     err %p  EIP %p   CS %p  flg %p\n"
+	.ascii "     vec %p  err %p  EIP %p   CS %p  flg %p\n"
 	.ascii "Stack: %p %p %p %p %p %p %p %p\n"
 	.ascii "       %p %p %p %p %p %p %p %p\n"
 	.asciz "       %p %p %p %p %p %p %p %p\n"
@@ -699,6 +733,7 @@ fault_msg:
  * segment size, and 32-bit linear address value:
  */
 
+	.data
 .globl boot_gdt_descr
 .globl idt_descr