From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Mon, 4 Aug 2014 23:56:16 +0000 (-0700)
Subject: Merge branches 'x86-build-for-linus', 'x86-cleanups-for-linus' and 'x86-debug-for... 
X-Git-Tag: MMI-PSA29.97-13-9~11808
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=19d402c1e75077e2bcfe17f7fe5bcfc8deb74991;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git

Merge branches 'x86-build-for-linus', 'x86-cleanups-for-linus' and 'x86-debug-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 build/cleanup/debug updates from Ingo Molnar:
 "Robustify the build process with a quirk to avoid GCC reordering
  related bugs.

  Two code cleanups.

  Simplify entry_64.S CFI annotations, by Jan Beulich"

* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, build: Change code16gcc.h from a C header to an assembly header

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Simplify __HAVE_ARCH_CMPXCHG tests
  x86/tsc: Get rid of custom DIV_ROUND() macro

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/debug: Drop several unnecessary CFI annotations
---

19d402c1e75077e2bcfe17f7fe5bcfc8deb74991
diff --cc arch/x86/kernel/entry_64.S
index c844f0816ab8,1e96c3628bf2,b25ca969edd2,f72c03a1ac54..2fac1343a90b
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@@@@ -830,46 -1040,13 -830,49 -829,49 +829,46 @@@@@ restore_args
    	RESTORE_ARGS 1,8,1
    
    irq_return:
  ++	INTERRUPT_RETURN
 -  	_ASM_EXTABLE(irq_return, bad_iret)
  ++
 -  #ifdef CONFIG_PARAVIRT
  ++ENTRY(native_iret)
 +  	/*
 +  	 * Are we returning to a stack segment from the LDT?  Note: in
 +  	 * 64-bit mode SS:RSP on the exception stack is always valid.
 +  	 */
 +  #ifdef CONFIG_X86_ESPFIX64
 +  	testb $4,(SS-RIP)(%rsp)
  --	jnz irq_return_ldt
 +++	jnz native_irq_return_ldt
 +  #endif
 +  
  --irq_return_iret:
  --	INTERRUPT_RETURN
  --	_ASM_EXTABLE(irq_return_iret, bad_iret)
  --
  --#ifdef CONFIG_PARAVIRT
  --ENTRY(native_iret)
 +++native_irq_return_iret:
    	iretq
 ---	_ASM_EXTABLE(native_iret, bad_iret)
  --#endif
 +++	_ASM_EXTABLE(native_irq_return_iret, bad_iret)
 +  
 +  #ifdef CONFIG_X86_ESPFIX64
  --irq_return_ldt:
 +++native_irq_return_ldt:
 +  	pushq_cfi %rax
 +  	pushq_cfi %rdi
 +  	SWAPGS
 +  	movq PER_CPU_VAR(espfix_waddr),%rdi
 +  	movq %rax,(0*8)(%rdi)	/* RAX */
 +  	movq (2*8)(%rsp),%rax	/* RIP */
 +  	movq %rax,(1*8)(%rdi)
 +  	movq (3*8)(%rsp),%rax	/* CS */
 +  	movq %rax,(2*8)(%rdi)
 +  	movq (4*8)(%rsp),%rax	/* RFLAGS */
 +  	movq %rax,(3*8)(%rdi)
 +  	movq (6*8)(%rsp),%rax	/* SS */
 +  	movq %rax,(5*8)(%rdi)
 +  	movq (5*8)(%rsp),%rax	/* RSP */
 +  	movq %rax,(4*8)(%rdi)
 +  	andl $0xffff0000,%eax
 +  	popq_cfi %rdi
 +  	orq PER_CPU_VAR(espfix_stack),%rax
 +  	SWAPGS
 +  	movq %rax,%rsp
 +  	popq_cfi %rax
  --	jmp irq_return_iret
 +++	jmp native_irq_return_iret
    #endif
    
    	.section .fixup,"ax"
@@@@@ -933,39 -1110,13 -936,44 -935,44 +932,39 @@@@@ ENTRY(retint_kernel
    	call preempt_schedule_irq
    	jmp exit_intr
    #endif
 -  
    	CFI_ENDPROC
    END(common_interrupt)
 -  /*
 -   * End of kprobes section
 -   */
 -         .popsection
 +  
 +  	/*
 +  	 * If IRET takes a fault on the espfix stack, then we
 +  	 * end up promoting it to a doublefault.  In that case,
 +  	 * modify the stack to make it look like we just entered
 +  	 * the #GP handler from user space, similar to bad_iret.
 +  	 */
 +  #ifdef CONFIG_X86_ESPFIX64
 +  	ALIGN
 +  __do_double_fault:
 +  	XCPT_FRAME 1 RDI+8
 +  	movq RSP(%rdi),%rax		/* Trap on the espfix stack? */
 +  	sarq $PGDIR_SHIFT,%rax
 +  	cmpl $ESPFIX_PGD_ENTRY,%eax
 +  	jne do_double_fault		/* No, just deliver the fault */
 +  	cmpl $__KERNEL_CS,CS(%rdi)
 +  	jne do_double_fault
 +  	movq RIP(%rdi),%rax
  --	cmpq $irq_return_iret,%rax
  --#ifdef CONFIG_PARAVIRT
  --	je 1f
  --	cmpq $native_iret,%rax
  --#endif
 +++	cmpq $native_irq_return_iret,%rax
 +  	jne do_double_fault		/* This shouldn't happen... */
  --1:
 +  	movq PER_CPU_VAR(kernel_stack),%rax
 +  	subq $(6*8-KERNEL_STACK_OFFSET),%rax	/* Reset to original stack */
 +  	movq %rax,RSP(%rdi)
 +  	movq $0,(%rax)			/* Missing (lost) #GP error code */
 +  	movq $general_protection,RIP(%rdi)
 +  	retq
 +  	CFI_ENDPROC
 +  END(__do_double_fault)
 +  #else
 +  # define __do_double_fault do_double_fault
 +  #endif
    
    /*
     * APIC interrupts.
@@@@@ -1419,8 -1600,8 -1427,8 -1426,9 +1418,9 @@@@@ error_sti
     * compat mode. Check for these here too.
     */
    error_kernelspace:
+++ 	CFI_REL_OFFSET rcx, RCX+8
    	incl %ebx
 -  	leaq irq_return(%rip),%rcx
  --	leaq irq_return_iret(%rip),%rcx
 +++	leaq native_irq_return_iret(%rip),%rcx
    	cmpq %rcx,RIP+8(%rsp)
    	je error_swapgs
    	movl %ecx,%eax	/* zero extend */