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Commit 83c2f912 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits)
  perf tools: Fix compile error on x86_64 Ubuntu
  perf report: Fix --stdio output alignment when --showcpuutilization used
  perf annotate: Get rid of field_sep check
  perf annotate: Fix usage string
  perf kmem: Fix a memory leak
  perf kmem: Add missing closedir() calls
  perf top: Add error message for EMFILE
  perf test: Change type of '-v' option to INCR
  perf script: Add missing closedir() calls
  tracing: Fix compile error when static ftrace is enabled
  recordmcount: Fix handling of elf64 big-endian objects.
  perf tools: Add const.h to MANIFEST to make perf-tar-src-pkg work again
  perf tools: Add support for guest/host-only profiling
  perf kvm: Do guest-only counting by default
  perf top: Don't update total_period on process_sample
  perf hists: Stop using 'self' for struct hist_entry
  perf hists: Rename total_session to total_period
  x86: Add counter when debug stack is used with interrupts enabled
  x86: Allow NMIs to hit breakpoints in i386
  x86: Keep current stack in NMI breakpoints
  ...
parents f0ed5b9a 172d1b0b

Documentation/kernel-parameters.txt

+8 −0
Original line number Diff line number Diff line
@@ -2475,6 +2475,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
	stacktrace	[FTRACE]

			Enabled the stack tracer on boot up.



	stacktrace_filter=[function-list]

			[FTRACE] Limit the functions that the stack tracer

			will trace at boot up. function-list is a comma separated

			list of functions. This list can be changed at run

			time by the stack_trace_filter file in the debugfs

			tracing directory. Note, this enables stack tracing

			and the stacktrace above is not needed.



	sti=		[PARISC,HW]

			Format: <num>

			Set the STI (builtin display/keyboard on the HP-PARISC

arch/x86/include/asm/debugreg.h

+22 −0
Original line number Diff line number Diff line
@@ -101,6 +101,28 @@ extern void aout_dump_debugregs(struct user *dump); 


extern void hw_breakpoint_restore(void);



#ifdef CONFIG_X86_64

DECLARE_PER_CPU(int, debug_stack_usage);

static inline void debug_stack_usage_inc(void)

{

	__get_cpu_var(debug_stack_usage)++;

}

static inline void debug_stack_usage_dec(void)

{

	__get_cpu_var(debug_stack_usage)--;

}

int is_debug_stack(unsigned long addr);

void debug_stack_set_zero(void);

void debug_stack_reset(void);

#else /* !X86_64 */

static inline int is_debug_stack(unsigned long addr) { return 0; }

static inline void debug_stack_set_zero(void) { }

static inline void debug_stack_reset(void) { }

static inline void debug_stack_usage_inc(void) { }

static inline void debug_stack_usage_dec(void) { }

#endif /* X86_64 */





#endif	/* __KERNEL__ */



#endif /* _ASM_X86_DEBUGREG_H */

arch/x86/include/asm/desc.h

+12 −0
Original line number Diff line number Diff line
@@ -35,6 +35,8 @@ static inline void fill_ldt(struct desc_struct *desc, const struct user_desc *in 


extern struct desc_ptr idt_descr;

extern gate_desc idt_table[];

extern struct desc_ptr nmi_idt_descr;

extern gate_desc nmi_idt_table[];



struct gdt_page {

	struct desc_struct gdt[GDT_ENTRIES];
@@ -307,6 +309,16 @@ static inline void set_desc_limit(struct desc_struct *desc, unsigned long limit) 
	desc->limit = (limit >> 16) & 0xf;

}



#ifdef CONFIG_X86_64

static inline void set_nmi_gate(int gate, void *addr)

{

	gate_desc s;



	pack_gate(&s, GATE_INTERRUPT, (unsigned long)addr, 0, 0, __KERNEL_CS);

	write_idt_entry(nmi_idt_table, gate, &s);

}

#endif



static inline void _set_gate(int gate, unsigned type, void *addr,

			     unsigned dpl, unsigned ist, unsigned seg)

{

arch/x86/kernel/cpu/common.c

+24 −0
Original line number Diff line number Diff line
@@ -1021,6 +1021,8 @@ __setup("clearcpuid=", setup_disablecpuid); 


#ifdef CONFIG_X86_64

struct desc_ptr idt_descr = { NR_VECTORS * 16 - 1, (unsigned long) idt_table };

struct desc_ptr nmi_idt_descr = { NR_VECTORS * 16 - 1,

				    (unsigned long) nmi_idt_table };



DEFINE_PER_CPU_FIRST(union irq_stack_union,

		     irq_stack_union) __aligned(PAGE_SIZE);
@@ -1085,6 +1087,26 @@ unsigned long kernel_eflags; 
 */

DEFINE_PER_CPU(struct orig_ist, orig_ist);



static DEFINE_PER_CPU(unsigned long, debug_stack_addr);

DEFINE_PER_CPU(int, debug_stack_usage);



int is_debug_stack(unsigned long addr)

{

	return __get_cpu_var(debug_stack_usage) ||

		(addr <= __get_cpu_var(debug_stack_addr) &&

		 addr > (__get_cpu_var(debug_stack_addr) - DEBUG_STKSZ));

}



void debug_stack_set_zero(void)

{

	load_idt((const struct desc_ptr *)&nmi_idt_descr);

}



void debug_stack_reset(void)

{

	load_idt((const struct desc_ptr *)&idt_descr);

}



#else	/* CONFIG_X86_64 */



DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
@@ -1212,6 +1234,8 @@ void __cpuinit cpu_init(void) 
			estacks += exception_stack_sizes[v];

			oist->ist[v] = t->x86_tss.ist[v] =

					(unsigned long)estacks;

			if (v == DEBUG_STACK-1)

				per_cpu(debug_stack_addr, cpu) = (unsigned long)estacks;

		}

	}

arch/x86/kernel/entry_64.S

+185 −33
Original line number Diff line number Diff line
@@ -1480,62 +1480,214 @@ ENTRY(error_exit) 
	CFI_ENDPROC

END(error_exit)



/*

 * Test if a given stack is an NMI stack or not.

 */

	.macro test_in_nmi reg stack nmi_ret normal_ret

	cmpq %\reg, \stack

	ja \normal_ret

	subq $EXCEPTION_STKSZ, %\reg

	cmpq %\reg, \stack

	jb \normal_ret

	jmp \nmi_ret

	.endm



	/* runs on exception stack */

ENTRY(nmi)

	INTR_FRAME

	PARAVIRT_ADJUST_EXCEPTION_FRAME

	pushq_cfi $-1

	/*

	 * We allow breakpoints in NMIs. If a breakpoint occurs, then

	 * the iretq it performs will take us out of NMI context.

	 * This means that we can have nested NMIs where the next

	 * NMI is using the top of the stack of the previous NMI. We

	 * can't let it execute because the nested NMI will corrupt the

	 * stack of the previous NMI. NMI handlers are not re-entrant

	 * anyway.

	 *

	 * To handle this case we do the following:

	 *  Check the a special location on the stack that contains

	 *  a variable that is set when NMIs are executing.

	 *  The interrupted task's stack is also checked to see if it

	 *  is an NMI stack.

	 *  If the variable is not set and the stack is not the NMI

	 *  stack then:

	 *    o Set the special variable on the stack

	 *    o Copy the interrupt frame into a "saved" location on the stack

	 *    o Copy the interrupt frame into a "copy" location on the stack

	 *    o Continue processing the NMI

	 *  If the variable is set or the previous stack is the NMI stack:

	 *    o Modify the "copy" location to jump to the repeate_nmi

	 *    o return back to the first NMI

	 *

	 * Now on exit of the first NMI, we first clear the stack variable

	 * The NMI stack will tell any nested NMIs at that point that it is

	 * nested. Then we pop the stack normally with iret, and if there was

	 * a nested NMI that updated the copy interrupt stack frame, a

	 * jump will be made to the repeat_nmi code that will handle the second

	 * NMI.

	 */



	/* Use %rdx as out temp variable throughout */

	pushq_cfi %rdx



	/*

	 * Check the special variable on the stack to see if NMIs are

	 * executing.

	 */

	cmp $1, -8(%rsp)

	je nested_nmi



	/*

	 * Now test if the previous stack was an NMI stack.

	 * We need the double check. We check the NMI stack to satisfy the

	 * race when the first NMI clears the variable before returning.

	 * We check the variable because the first NMI could be in a

	 * breakpoint routine using a breakpoint stack.

	 */

	lea 6*8(%rsp), %rdx

	test_in_nmi rdx, 4*8(%rsp), nested_nmi, first_nmi



nested_nmi:

	/*

	 * Do nothing if we interrupted the fixup in repeat_nmi.

	 * It's about to repeat the NMI handler, so we are fine

	 * with ignoring this one.

	 */

	movq $repeat_nmi, %rdx

	cmpq 8(%rsp), %rdx

	ja 1f

	movq $end_repeat_nmi, %rdx

	cmpq 8(%rsp), %rdx

	ja nested_nmi_out



1:

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

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

	movq %rdx, %rsp

	CFI_ADJUST_CFA_OFFSET 6*8

	pushq_cfi $__KERNEL_DS

	pushq_cfi %rdx

	pushfq_cfi

	pushq_cfi $__KERNEL_CS

	pushq_cfi $repeat_nmi



	/* Put stack back */

	addq $(11*8), %rsp

	CFI_ADJUST_CFA_OFFSET -11*8



nested_nmi_out:

	popq_cfi %rdx



	/* No need to check faults here */

	INTERRUPT_RETURN



first_nmi:

	/*

	 * Because nested NMIs will use the pushed location that we

	 * stored in rdx, we must keep that space available.

	 * Here's what our stack frame will look like:

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

	 * | original SS             |

	 * | original Return RSP     |

	 * | original RFLAGS         |

	 * | original CS             |

	 * | original RIP            |

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

	 * | temp storage for rdx    |

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

	 * | 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              |

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

	 * | pt_regs                 |

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

	 *

	 * The saved RIP is used to fix up the copied RIP that a nested

	 * NMI may zero out. The original stack frame and the temp storage

	 * is also used by nested NMIs and can not be trusted on exit.

	 */

	/* Set the NMI executing variable on the stack. */

	pushq_cfi $1



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

	.rept 5

	pushq_cfi 6*8(%rsp)

	.endr



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

	.rept 5

	pushq_cfi 4*8(%rsp)

	.endr



	/* Do not pop rdx, nested NMIs will corrupt it */

	movq 11*8(%rsp), %rdx



	/*

	 * Everything below this point can be preempted by a nested

	 * NMI if the first NMI took an exception. Repeated NMIs

	 * caused by an exception and nested NMI will start here, and

	 * can still be preempted by another NMI.

	 */

restart_nmi:

	pushq_cfi $-1		/* ORIG_RAX: no syscall to restart */

	subq $ORIG_RAX-R15, %rsp

	CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15

	/*

	 * Use save_paranoid to handle SWAPGS, but no need to use paranoid_exit

	 * as we should not be calling schedule in NMI context.

	 * Even with normal interrupts enabled. An NMI should not be

	 * setting NEED_RESCHED or anything that normal interrupts and

	 * exceptions might do.

	 */

	call save_paranoid

	DEFAULT_FRAME 0

	/* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */

	movq %rsp,%rdi

	movq $-1,%rsi

	call do_nmi

#ifdef CONFIG_TRACE_IRQFLAGS

	/* paranoidexit; without TRACE_IRQS_OFF */

	/* ebx:	no swapgs flag */

	DISABLE_INTERRUPTS(CLBR_NONE)

	testl %ebx,%ebx				/* swapgs needed? */

	jnz nmi_restore

	testl $3,CS(%rsp)

	jnz nmi_userspace

nmi_swapgs:

	SWAPGS_UNSAFE_STACK

nmi_restore:

	RESTORE_ALL 8

	/* Clear the NMI executing stack variable */

	movq $0, 10*8(%rsp)

	jmp irq_return

nmi_userspace:

	GET_THREAD_INFO(%rcx)

	movl TI_flags(%rcx),%ebx

	andl $_TIF_WORK_MASK,%ebx

	jz nmi_swapgs

	movq %rsp,%rdi			/* &pt_regs */

	call sync_regs

	movq %rax,%rsp			/* switch stack for scheduling */

	testl $_TIF_NEED_RESCHED,%ebx

	jnz nmi_schedule

	movl %ebx,%edx			/* arg3: thread flags */

	ENABLE_INTERRUPTS(CLBR_NONE)

	xorl %esi,%esi 			/* arg2: oldset */

	movq %rsp,%rdi 			/* arg1: &pt_regs */

	call do_notify_resume

	DISABLE_INTERRUPTS(CLBR_NONE)

	jmp nmi_userspace

nmi_schedule:

	ENABLE_INTERRUPTS(CLBR_ANY)

	call schedule

	DISABLE_INTERRUPTS(CLBR_ANY)

	jmp nmi_userspace

	CFI_ENDPROC

#else

	jmp paranoid_exit

	CFI_ENDPROC

#endif

END(nmi)



	/*

	 * If an NMI hit an iret because of an exception or breakpoint,

	 * it can lose its NMI context, and a nested NMI may come in.

	 * In that case, the nested NMI will change the preempted NMI's

	 * stack to jump to here when it does the final iret.

	 */

repeat_nmi:

	INTR_FRAME

	/* Update the stack variable to say we are still in NMI */

	movq $1, 5*8(%rsp)



	/* copy the saved stack back to copy stack */

	.rept 5

	pushq_cfi 4*8(%rsp)

	.endr



	jmp restart_nmi

	CFI_ENDPROC

end_repeat_nmi:



ENTRY(ignore_sysret)

	CFI_STARTPROC

	mov $-ENOSYS,%eax