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Commit 5645688f 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 updates from Ingo Molnar:
 "The main changes in this development cycle were:

   - a large number of call stack dumping/printing improvements: higher
     robustness, better cross-context dumping, improved output, etc.
     (Josh Poimboeuf)

   - vDSO getcpu() performance improvement for future Intel CPUs with
     the RDPID instruction (Andy Lutomirski)

   - add two new Intel AVX512 features and the CPUID support
     infrastructure for it: AVX512IFMA and AVX512VBMI. (Gayatri Kammela,
     He Chen)

   - more copy-user unification (Borislav Petkov)

   - entry code assembly macro simplifications (Alexander Kuleshov)

   - vDSO C/R support improvements (Dmitry Safonov)

   - misc fixes and cleanups (Borislav Petkov, Paul Bolle)"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  scripts/decode_stacktrace.sh: Fix address line detection on x86
  x86/boot/64: Use defines for page size
  x86/dumpstack: Make stack name tags more comprehensible
  selftests/x86: Add test_vdso to test getcpu()
  x86/vdso: Use RDPID in preference to LSL when available
  x86/dumpstack: Handle NULL stack pointer in show_trace_log_lvl()
  x86/cpufeatures: Enable new AVX512 cpu features
  x86/cpuid: Provide get_scattered_cpuid_leaf()
  x86/cpuid: Cleanup cpuid_regs definitions
  x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants
  x86/unwind: Ensure stack grows down
  x86/vdso: Set vDSO pointer only after success
  x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE
  x86/unwind: Detect bad stack return address
  x86/dumpstack: Warn on stack recursion
  x86/unwind: Warn on bad frame pointer
  x86/decoder: Use stderr if insn sanity test fails
  x86/decoder: Use stdout if insn decoder test is successful
  mm/page_alloc: Remove kernel address exposure in free_reserved_area()
  x86/dumpstack: Remove raw stack dump
  ...
parents 4ade5b22 53938ee4

Documentation/kernel-parameters.txt

+0 −3
Original line number Diff line number Diff line
@@ -1963,9 +1963,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
			kmemcheck=2 (one-shot mode)

			Default: 2 (one-shot mode)



	kstack=N	[X86] Print N words from the kernel stack

			in oops dumps.



	kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.

			Default is 0 (don't ignore, but inject #GP)

Documentation/sysctl/kernel.txt

+0 −8
Original line number Diff line number Diff line
@@ -40,7 +40,6 @@ show up in /proc/sys/kernel: 
- hung_task_warnings

- kexec_load_disabled

- kptr_restrict

- kstack_depth_to_print       [ X86 only ]

- l2cr                        [ PPC only ]

- modprobe                    ==> Documentation/debugging-modules.txt

- modules_disabled
@@ -395,13 +394,6 @@ When kptr_restrict is set to (2), kernel pointers printed using 


==============================================================



kstack_depth_to_print: (X86 only)



Controls the number of words to print when dumping the raw

kernel stack.



==============================================================



l2cr: (PPC only)



This flag controls the L2 cache of G3 processor boards. If

Documentation/x86/x86_64/boot-options.txt

+0 −4
Original line number Diff line number Diff line
@@ -277,10 +277,6 @@ IOMMU (input/output memory management unit) 
    space might stop working. Use this option if you have devices that

    are accessed from userspace directly on some PCI host bridge.



Debugging



  kstack=N	Print N words from the kernel stack in oops dumps.



Miscellaneous



	nogbpages

arch/x86/entry/calling.h

+22 −11
Original line number Diff line number Diff line
@@ -90,8 +90,8 @@ For 32-bit we have the following conventions - kernel is built with 


#define SIZEOF_PTREGS	21*8



	.macro ALLOC_PT_GPREGS_ON_STACK addskip=0

	addq	$-(15*8+\addskip), %rsp

	.macro ALLOC_PT_GPREGS_ON_STACK

	addq	$-(15*8), %rsp

	.endm



	.macro SAVE_C_REGS_HELPER offset=0 rax=1 rcx=1 r8910=1 r11=1
@@ -147,15 +147,6 @@ For 32-bit we have the following conventions - kernel is built with 
	movq 5*8+\offset(%rsp), %rbx

	.endm



	.macro ZERO_EXTRA_REGS

	xorl	%r15d, %r15d

	xorl	%r14d, %r14d

	xorl	%r13d, %r13d

	xorl	%r12d, %r12d

	xorl	%ebp, %ebp

	xorl	%ebx, %ebx

	.endm



	.macro RESTORE_C_REGS_HELPER rstor_rax=1, rstor_rcx=1, rstor_r11=1, rstor_r8910=1, rstor_rdx=1

	.if \rstor_r11

	movq 6*8(%rsp), %r11
@@ -201,6 +192,26 @@ For 32-bit we have the following conventions - kernel is built with 
	.byte 0xf1

	.endm



/*

 * This is a sneaky trick to help the unwinder find pt_regs on the stack.  The

 * frame pointer is replaced with an encoded pointer to pt_regs.  The encoding

 * is just setting the LSB, which makes it an invalid stack address and is also

 * a signal to the unwinder that it's a pt_regs pointer in disguise.

 *

 * NOTE: This macro must be used *after* SAVE_EXTRA_REGS because it corrupts

 * the original rbp.

 */

.macro ENCODE_FRAME_POINTER ptregs_offset=0

#ifdef CONFIG_FRAME_POINTER

	.if \ptregs_offset

		leaq \ptregs_offset(%rsp), %rbp

	.else

		mov %rsp, %rbp

	.endif

	orq	$0x1, %rbp

#endif

.endm



#endif /* CONFIG_X86_64 */



/*

arch/x86/entry/entry_32.S

+93 −48
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ 
#include <asm/asm.h>

#include <asm/smap.h>

#include <asm/export.h>

#include <asm/frame.h>



	.section .entry.text, "ax"
@@ -175,6 +176,22 @@ 
	SET_KERNEL_GS %edx

.endm



/*

 * This is a sneaky trick to help the unwinder find pt_regs on the stack.  The

 * frame pointer is replaced with an encoded pointer to pt_regs.  The encoding

 * is just setting the LSB, which makes it an invalid stack address and is also

 * a signal to the unwinder that it's a pt_regs pointer in disguise.

 *

 * NOTE: This macro must be used *after* SAVE_ALL because it corrupts the

 * original rbp.

 */

.macro ENCODE_FRAME_POINTER

#ifdef CONFIG_FRAME_POINTER

	mov %esp, %ebp

	orl $0x1, %ebp

#endif

.endm



.macro RESTORE_INT_REGS

	popl	%ebx

	popl	%ecx
@@ -237,6 +254,23 @@ ENTRY(__switch_to_asm) 
	jmp	__switch_to

END(__switch_to_asm)



/*

 * The unwinder expects the last frame on the stack to always be at the same

 * offset from the end of the page, which allows it to validate the stack.

 * Calling schedule_tail() directly would break that convention because its an

 * asmlinkage function so its argument has to be pushed on the stack.  This

 * wrapper creates a proper "end of stack" frame header before the call.

 */

ENTRY(schedule_tail_wrapper)

	FRAME_BEGIN



	pushl	%eax

	call	schedule_tail

	popl	%eax



	FRAME_END

	ret

ENDPROC(schedule_tail_wrapper)

/*

 * A newly forked process directly context switches into this address.

 *
@@ -245,9 +279,7 @@ END(__switch_to_asm) 
 * edi: kernel thread arg

 */

ENTRY(ret_from_fork)

	pushl	%eax

	call	schedule_tail

	popl	%eax

	call	schedule_tail_wrapper



	testl	%ebx, %ebx

	jnz	1f		/* kernel threads are uncommon */
@@ -307,13 +339,13 @@ END(ret_from_exception) 
#ifdef CONFIG_PREEMPT

ENTRY(resume_kernel)

	DISABLE_INTERRUPTS(CLBR_ANY)

need_resched:

.Lneed_resched:

	cmpl	$0, PER_CPU_VAR(__preempt_count)

	jnz	restore_all

	testl	$X86_EFLAGS_IF, PT_EFLAGS(%esp)	# interrupts off (exception path) ?

	jz	restore_all

	call	preempt_schedule_irq

	jmp	need_resched

	jmp	.Lneed_resched

END(resume_kernel)

#endif
@@ -334,7 +366,7 @@ GLOBAL(__begin_SYSENTER_singlestep_region) 
 */

ENTRY(xen_sysenter_target)

	addl	$5*4, %esp			/* remove xen-provided frame */

	jmp	sysenter_past_esp

	jmp	.Lsysenter_past_esp

#endif



/*
@@ -371,7 +403,7 @@ ENTRY(xen_sysenter_target) 
 */

ENTRY(entry_SYSENTER_32)

	movl	TSS_sysenter_sp0(%esp), %esp

sysenter_past_esp:

.Lsysenter_past_esp:

	pushl	$__USER_DS		/* pt_regs->ss */

	pushl	%ebp			/* pt_regs->sp (stashed in bp) */

	pushfl				/* pt_regs->flags (except IF = 0) */
@@ -504,9 +536,9 @@ ENTRY(entry_INT80_32) 


restore_all:

	TRACE_IRQS_IRET

restore_all_notrace:

.Lrestore_all_notrace:

#ifdef CONFIG_X86_ESPFIX32

	ALTERNATIVE	"jmp restore_nocheck", "", X86_BUG_ESPFIX

	ALTERNATIVE	"jmp .Lrestore_nocheck", "", X86_BUG_ESPFIX



	movl	PT_EFLAGS(%esp), %eax		# mix EFLAGS, SS and CS

	/*
@@ -518,22 +550,23 @@ restore_all_notrace: 
	movb	PT_CS(%esp), %al

	andl	$(X86_EFLAGS_VM | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax

	cmpl	$((SEGMENT_LDT << 8) | USER_RPL), %eax

	je ldt_ss				# returning to user-space with LDT SS

	je .Lldt_ss				# returning to user-space with LDT SS

#endif

restore_nocheck:

.Lrestore_nocheck:

	RESTORE_REGS 4				# skip orig_eax/error_code

irq_return:

.Lirq_return:

	INTERRUPT_RETURN



.section .fixup, "ax"

ENTRY(iret_exc	)

	pushl	$0				# no error code

	pushl	$do_iret_error

	jmp	error_code

	jmp	common_exception

.previous

	_ASM_EXTABLE(irq_return, iret_exc)

	_ASM_EXTABLE(.Lirq_return, iret_exc)



#ifdef CONFIG_X86_ESPFIX32

ldt_ss:

.Lldt_ss:

/*

 * Setup and switch to ESPFIX stack

 *
@@ -562,7 +595,7 @@ ldt_ss: 
	 */

	DISABLE_INTERRUPTS(CLBR_EAX)

	lss	(%esp), %esp			/* switch to espfix segment */

	jmp	restore_nocheck

	jmp	.Lrestore_nocheck

#endif

ENDPROC(entry_INT80_32)
@@ -624,6 +657,7 @@ common_interrupt: 
	ASM_CLAC

	addl	$-0x80, (%esp)			/* Adjust vector into the [-256, -1] range */

	SAVE_ALL

	ENCODE_FRAME_POINTER

	TRACE_IRQS_OFF

	movl	%esp, %eax

	call	do_IRQ
@@ -635,6 +669,7 @@ ENTRY(name) \ 
	ASM_CLAC;			\

	pushl	$~(nr);			\

	SAVE_ALL;			\

	ENCODE_FRAME_POINTER;		\

	TRACE_IRQS_OFF			\

	movl	%esp, %eax;		\

	call	fn;			\
@@ -659,7 +694,7 @@ ENTRY(coprocessor_error) 
	ASM_CLAC

	pushl	$0

	pushl	$do_coprocessor_error

	jmp	error_code

	jmp	common_exception

END(coprocessor_error)



ENTRY(simd_coprocessor_error)
@@ -673,14 +708,14 @@ ENTRY(simd_coprocessor_error) 
#else

	pushl	$do_simd_coprocessor_error

#endif

	jmp	error_code

	jmp	common_exception

END(simd_coprocessor_error)



ENTRY(device_not_available)

	ASM_CLAC

	pushl	$-1				# mark this as an int

	pushl	$do_device_not_available

	jmp	error_code

	jmp	common_exception

END(device_not_available)



#ifdef CONFIG_PARAVIRT
@@ -694,59 +729,59 @@ ENTRY(overflow) 
	ASM_CLAC

	pushl	$0

	pushl	$do_overflow

	jmp	error_code

	jmp	common_exception

END(overflow)



ENTRY(bounds)

	ASM_CLAC

	pushl	$0

	pushl	$do_bounds

	jmp	error_code

	jmp	common_exception

END(bounds)



ENTRY(invalid_op)

	ASM_CLAC

	pushl	$0

	pushl	$do_invalid_op

	jmp	error_code

	jmp	common_exception

END(invalid_op)



ENTRY(coprocessor_segment_overrun)

	ASM_CLAC

	pushl	$0

	pushl	$do_coprocessor_segment_overrun

	jmp	error_code

	jmp	common_exception

END(coprocessor_segment_overrun)



ENTRY(invalid_TSS)

	ASM_CLAC

	pushl	$do_invalid_TSS

	jmp	error_code

	jmp	common_exception

END(invalid_TSS)



ENTRY(segment_not_present)

	ASM_CLAC

	pushl	$do_segment_not_present

	jmp	error_code

	jmp	common_exception

END(segment_not_present)



ENTRY(stack_segment)

	ASM_CLAC

	pushl	$do_stack_segment

	jmp	error_code

	jmp	common_exception

END(stack_segment)



ENTRY(alignment_check)

	ASM_CLAC

	pushl	$do_alignment_check

	jmp	error_code

	jmp	common_exception

END(alignment_check)



ENTRY(divide_error)

	ASM_CLAC

	pushl	$0				# no error code

	pushl	$do_divide_error

	jmp	error_code

	jmp	common_exception

END(divide_error)



#ifdef CONFIG_X86_MCE
@@ -754,7 +789,7 @@ ENTRY(machine_check) 
	ASM_CLAC

	pushl	$0

	pushl	machine_check_vector

	jmp	error_code

	jmp	common_exception

END(machine_check)

#endif
@@ -762,13 +797,14 @@ ENTRY(spurious_interrupt_bug) 
	ASM_CLAC

	pushl	$0

	pushl	$do_spurious_interrupt_bug

	jmp	error_code

	jmp	common_exception

END(spurious_interrupt_bug)



#ifdef CONFIG_XEN

ENTRY(xen_hypervisor_callback)

	pushl	$-1				/* orig_ax = -1 => not a system call */

	SAVE_ALL

	ENCODE_FRAME_POINTER

	TRACE_IRQS_OFF



	/*
@@ -823,6 +859,7 @@ ENTRY(xen_failsafe_callback) 
	jmp	iret_exc

5:	pushl	$-1				/* orig_ax = -1 => not a system call */

	SAVE_ALL

	ENCODE_FRAME_POINTER

	jmp	ret_from_exception



.section .fixup, "ax"
@@ -882,7 +919,7 @@ ftrace_call: 
	popl	%edx

	popl	%ecx

	popl	%eax

ftrace_ret:

.Lftrace_ret:

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

.globl ftrace_graph_call

ftrace_graph_call:
@@ -952,7 +989,7 @@ GLOBAL(ftrace_regs_call) 
	popl	%gs

	addl	$8, %esp			/* Skip orig_ax and ip */

	popf					/* Pop flags at end (no addl to corrupt flags) */

	jmp	ftrace_ret

	jmp	.Lftrace_ret



	popf

	jmp	ftrace_stub
@@ -963,7 +1000,7 @@ ENTRY(mcount) 
	jb	ftrace_stub			/* Paging not enabled yet? */



	cmpl	$ftrace_stub, ftrace_trace_function

	jnz	trace

	jnz	.Ltrace

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

	cmpl	$ftrace_stub, ftrace_graph_return

	jnz	ftrace_graph_caller
@@ -976,7 +1013,7 @@ ftrace_stub: 
	ret



	/* taken from glibc */

trace:

.Ltrace:

	pushl	%eax

	pushl	%ecx

	pushl	%edx
@@ -1027,7 +1064,7 @@ return_to_handler: 
ENTRY(trace_page_fault)

	ASM_CLAC

	pushl	$trace_do_page_fault

	jmp	error_code

	jmp	common_exception

END(trace_page_fault)

#endif
@@ -1035,7 +1072,10 @@ ENTRY(page_fault) 
	ASM_CLAC

	pushl	$do_page_fault

	ALIGN

error_code:

	jmp common_exception

END(page_fault)



common_exception:

	/* the function address is in %gs's slot on the stack */

	pushl	%fs

	pushl	%es
@@ -1047,6 +1087,7 @@ error_code: 
	pushl	%edx

	pushl	%ecx

	pushl	%ebx

	ENCODE_FRAME_POINTER

	cld

	movl	$(__KERNEL_PERCPU), %ecx

	movl	%ecx, %fs
@@ -1064,7 +1105,7 @@ error_code: 
	movl	%esp, %eax			# pt_regs pointer

	call	*%edi

	jmp	ret_from_exception

END(page_fault)

END(common_exception)



ENTRY(debug)

	/*
@@ -1079,6 +1120,7 @@ ENTRY(debug) 
	ASM_CLAC

	pushl	$-1				# mark this as an int

	SAVE_ALL

	ENCODE_FRAME_POINTER

	xorl	%edx, %edx			# error code 0

	movl	%esp, %eax			# pt_regs pointer
@@ -1094,11 +1136,11 @@ ENTRY(debug) 


.Ldebug_from_sysenter_stack:

	/* We're on the SYSENTER stack.  Switch off. */

	movl	%esp, %ebp

	movl	%esp, %ebx

	movl	PER_CPU_VAR(cpu_current_top_of_stack), %esp

	TRACE_IRQS_OFF

	call	do_debug

	movl	%ebp, %esp

	movl	%ebx, %esp

	jmp	ret_from_exception

END(debug)
@@ -1116,11 +1158,12 @@ ENTRY(nmi) 
	movl	%ss, %eax

	cmpw	$__ESPFIX_SS, %ax

	popl	%eax

	je	nmi_espfix_stack

	je	.Lnmi_espfix_stack

#endif



	pushl	%eax				# pt_regs->orig_ax

	SAVE_ALL

	ENCODE_FRAME_POINTER

	xorl	%edx, %edx			# zero error code

	movl	%esp, %eax			# pt_regs pointer
@@ -1132,21 +1175,21 @@ ENTRY(nmi) 


	/* Not on SYSENTER stack. */

	call	do_nmi

	jmp	restore_all_notrace

	jmp	.Lrestore_all_notrace



.Lnmi_from_sysenter_stack:

	/*

	 * We're on the SYSENTER stack.  Switch off.  No one (not even debug)

	 * is using the thread stack right now, so it's safe for us to use it.

	 */

	movl	%esp, %ebp

	movl	%esp, %ebx

	movl	PER_CPU_VAR(cpu_current_top_of_stack), %esp

	call	do_nmi

	movl	%ebp, %esp

	jmp	restore_all_notrace

	movl	%ebx, %esp

	jmp	.Lrestore_all_notrace



#ifdef CONFIG_X86_ESPFIX32

nmi_espfix_stack:

.Lnmi_espfix_stack:

	/*

	 * create the pointer to lss back

	 */
@@ -1159,12 +1202,13 @@ nmi_espfix_stack: 
	.endr

	pushl	%eax

	SAVE_ALL

	ENCODE_FRAME_POINTER

	FIXUP_ESPFIX_STACK			# %eax == %esp

	xorl	%edx, %edx			# zero error code

	call	do_nmi

	RESTORE_REGS

	lss	12+4(%esp), %esp		# back to espfix stack

	jmp	irq_return

	jmp	.Lirq_return

#endif

END(nmi)
@@ -1172,6 +1216,7 @@ ENTRY(int3) 
	ASM_CLAC

	pushl	$-1				# mark this as an int

	SAVE_ALL

	ENCODE_FRAME_POINTER

	TRACE_IRQS_OFF

	xorl	%edx, %edx			# zero error code

	movl	%esp, %eax			# pt_regs pointer
@@ -1181,14 +1226,14 @@ END(int3) 


ENTRY(general_protection)

	pushl	$do_general_protection

	jmp	error_code

	jmp	common_exception

END(general_protection)



#ifdef CONFIG_KVM_GUEST

ENTRY(async_page_fault)

	ASM_CLAC

	pushl	$do_async_page_fault

	jmp	error_code

	jmp	common_exception

END(async_page_fault)

#endif