Commit 0019fab3 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

Pull x86 asm changes from Ingo Molnar:
 "Two fixlets and a cleanup."

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86_32: Return actual stack when requesting sp from regs
  x86: Don't clobber top of pt_regs in nested NMI
  x86/asm: Clean up copy_page_*() comments and code
parents b64c5fda 6c8d8b3c

arch/x86/include/asm/ptrace.h

+9 −0
Original line number Diff line number Diff line
@@ -239,6 +239,15 @@ static inline unsigned long regs_get_register(struct pt_regs *regs, 
{

	if (unlikely(offset > MAX_REG_OFFSET))

		return 0;

#ifdef CONFIG_X86_32

	/*

	 * Traps from the kernel do not save sp and ss.

	 * Use the helper function to retrieve sp.

	 */

	if (offset == offsetof(struct pt_regs, sp) &&

	    regs->cs == __KERNEL_CS)

		return kernel_stack_pointer(regs);

#endif

	return *(unsigned long *)((unsigned long)regs + offset);

}

arch/x86/kernel/entry_64.S

+27 −14
Original line number Diff line number Diff line
@@ -1699,9 +1699,10 @@ nested_nmi: 


1:

	/* Set up the interrupted NMIs stack to jump to repeat_nmi */

	leaq -6*8(%rsp), %rdx

	leaq -1*8(%rsp), %rdx

	movq %rdx, %rsp

	CFI_ADJUST_CFA_OFFSET 6*8

	CFI_ADJUST_CFA_OFFSET 1*8

	leaq -10*8(%rsp), %rdx

	pushq_cfi $__KERNEL_DS

	pushq_cfi %rdx

	pushfq_cfi
@@ -1709,8 +1710,8 @@ nested_nmi: 
	pushq_cfi $repeat_nmi



	/* Put stack back */

	addq $(11*8), %rsp

	CFI_ADJUST_CFA_OFFSET -11*8

	addq $(6*8), %rsp

	CFI_ADJUST_CFA_OFFSET -6*8



nested_nmi_out:

	popq_cfi %rdx
@@ -1736,18 +1737,18 @@ first_nmi: 
	 * +-------------------------+

	 * | NMI executing variable  |

	 * +-------------------------+

	 * | Saved SS                |

	 * | Saved Return RSP        |

	 * | Saved RFLAGS            |

	 * | Saved CS                |

	 * | Saved RIP               |

	 * +-------------------------+

	 * | copied SS               |

	 * | copied Return RSP       |

	 * | copied RFLAGS           |

	 * | copied CS               |

	 * | copied RIP              |

	 * +-------------------------+

	 * | Saved SS                |

	 * | Saved Return RSP        |

	 * | Saved RFLAGS            |

	 * | Saved CS                |

	 * | Saved RIP               |

	 * +-------------------------+

	 * | pt_regs                 |

	 * +-------------------------+

	 *
@@ -1763,9 +1764,14 @@ first_nmi: 
	/* Set the NMI executing variable on the stack. */

	pushq_cfi $1



	/*

	 * Leave room for the "copied" frame

	 */

	subq $(5*8), %rsp



	/* Copy the stack frame to the Saved frame */

	.rept 5

	pushq_cfi 6*8(%rsp)

	pushq_cfi 11*8(%rsp)

	.endr

	CFI_DEF_CFA_OFFSET SS+8-RIP
@@ -1786,12 +1792,15 @@ repeat_nmi: 
	 * is benign for the non-repeat case, where 1 was pushed just above

	 * to this very stack slot).

	 */

	movq $1, 5*8(%rsp)

	movq $1, 10*8(%rsp)



	/* Make another copy, this one may be modified by nested NMIs */

	addq $(10*8), %rsp

	CFI_ADJUST_CFA_OFFSET -10*8

	.rept 5

	pushq_cfi 4*8(%rsp)

	pushq_cfi -6*8(%rsp)

	.endr

	subq $(5*8), %rsp

	CFI_DEF_CFA_OFFSET SS+8-RIP

end_repeat_nmi:
@@ -1842,8 +1851,12 @@ nmi_swapgs: 
	SWAPGS_UNSAFE_STACK

nmi_restore:

	RESTORE_ALL 8



	/* Pop the extra iret frame */

	addq $(5*8), %rsp



	/* Clear the NMI executing stack variable */

	movq $0, 10*8(%rsp)

	movq $0, 5*8(%rsp)

	jmp irq_return

	CFI_ENDPROC

END(nmi)

arch/x86/lib/copy_page_64.S

+59 −61
Original line number Diff line number Diff line
@@ -5,18 +5,18 @@ 
#include <asm/alternative-asm.h>



	ALIGN

copy_page_c:

copy_page_rep:

	CFI_STARTPROC

	movl	$4096/8, %ecx

	rep	movsq

	ret

	CFI_ENDPROC

ENDPROC(copy_page_c)

ENDPROC(copy_page_rep)



/* Don't use streaming store because it's better when the target

   ends up in cache. */

	    

/* Could vary the prefetch distance based on SMP/UP */

/*

 *  Don't use streaming copy unless the CPU indicates X86_FEATURE_REP_GOOD.

 *  Could vary the prefetch distance based on SMP/UP.

*/



ENTRY(copy_page)

	CFI_STARTPROC
@@ -31,26 +31,25 @@ ENTRY(copy_page) 
	.p2align 4

.Loop64:

	dec	%rcx



	movq        (%rsi), %rax

	movq      8 (%rsi), %rbx

	movq     16 (%rsi), %rdx

	movq     24 (%rsi), %r8

	movq     32 (%rsi), %r9

	movq     40 (%rsi), %r10

	movq     48 (%rsi), %r11

	movq     56 (%rsi), %r12

	movq	0x8*0(%rsi), %rax

	movq	0x8*1(%rsi), %rbx

	movq	0x8*2(%rsi), %rdx

	movq	0x8*3(%rsi), %r8

	movq	0x8*4(%rsi), %r9

	movq	0x8*5(%rsi), %r10

	movq	0x8*6(%rsi), %r11

	movq	0x8*7(%rsi), %r12



	prefetcht0 5*64(%rsi)



	movq     %rax,    (%rdi)

	movq     %rbx,  8 (%rdi)

	movq     %rdx, 16 (%rdi)

	movq     %r8,  24 (%rdi)

	movq     %r9,  32 (%rdi)

	movq     %r10, 40 (%rdi)

	movq     %r11, 48 (%rdi)

	movq     %r12, 56 (%rdi)

	movq	%rax, 0x8*0(%rdi)

	movq	%rbx, 0x8*1(%rdi)

	movq	%rdx, 0x8*2(%rdi)

	movq	%r8,  0x8*3(%rdi)

	movq	%r9,  0x8*4(%rdi)

	movq	%r10, 0x8*5(%rdi)

	movq	%r11, 0x8*6(%rdi)

	movq	%r12, 0x8*7(%rdi)



	leaq	64 (%rsi), %rsi

	leaq	64 (%rdi), %rdi
@@ -62,27 +61,26 @@ ENTRY(copy_page) 
.Loop2:

	decl	%ecx



	movq        (%rsi), %rax

	movq      8 (%rsi), %rbx

	movq     16 (%rsi), %rdx

	movq     24 (%rsi), %r8

	movq     32 (%rsi), %r9

	movq     40 (%rsi), %r10

	movq     48 (%rsi), %r11

	movq     56 (%rsi), %r12



	movq     %rax,    (%rdi)

	movq     %rbx,  8 (%rdi)

	movq     %rdx, 16 (%rdi)

	movq     %r8,  24 (%rdi)

	movq     %r9,  32 (%rdi)

	movq     %r10, 40 (%rdi)

	movq     %r11, 48 (%rdi)

	movq     %r12, 56 (%rdi)

	movq	0x8*0(%rsi), %rax

	movq	0x8*1(%rsi), %rbx

	movq	0x8*2(%rsi), %rdx

	movq	0x8*3(%rsi), %r8

	movq	0x8*4(%rsi), %r9

	movq	0x8*5(%rsi), %r10

	movq	0x8*6(%rsi), %r11

	movq	0x8*7(%rsi), %r12



	movq	%rax, 0x8*0(%rdi)

	movq	%rbx, 0x8*1(%rdi)

	movq	%rdx, 0x8*2(%rdi)

	movq	%r8,  0x8*3(%rdi)

	movq	%r9,  0x8*4(%rdi)

	movq	%r10, 0x8*5(%rdi)

	movq	%r11, 0x8*6(%rdi)

	movq	%r12, 0x8*7(%rdi)



	leaq	64(%rdi), %rdi

	leaq	64(%rsi), %rsi



	jnz	.Loop2



	movq	(%rsp), %rbx
@@ -103,7 +101,7 @@ ENDPROC(copy_page) 


	.section .altinstr_replacement,"ax"

1:	.byte 0xeb					/* jmp <disp8> */

	.byte (copy_page_c - copy_page) - (2f - 1b)	/* offset */

	.byte (copy_page_rep - copy_page) - (2f - 1b)	/* offset */

2:

	.previous

	.section .altinstructions,"a"