Commit 75da04f7 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

x86/entry: Remove the apic/BUILD interrupt leftovers 



Remove all the code which was there to emit the system vector stubs. All
users are gone.

Move the now unused GET_CR2_INTO macro muck to head_64.S where the last
user is. Fixup the eye hurting comment there while at it.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Acked-by: default avatarAndy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200521202119.927433002@linutronix.de
parent 13cad985

arch/x86/entry/calling.h

+0 −20
Original line number Diff line number Diff line
@@ -351,23 +351,3 @@ For 32-bit we have the following conventions - kernel is built with 
	call stackleak_erase

#endif

.endm
 


/*

 * This does 'call enter_from_user_mode' unless we can avoid it based on

 * kernel config or using the static jump infrastructure.

 */

.macro CALL_enter_from_user_mode

#ifdef CONFIG_CONTEXT_TRACKING

#ifdef CONFIG_JUMP_LABEL

	STATIC_JUMP_IF_FALSE .Lafter_call_\@, context_tracking_key, def=0

#endif

	call enter_from_user_mode

.Lafter_call_\@:

#endif

.endm



#ifdef CONFIG_PARAVIRT_XXL

#define GET_CR2_INTO(reg) GET_CR2_INTO_AX ; _ASM_MOV %_ASM_AX, reg

#else

#define GET_CR2_INTO(reg) _ASM_MOV %cr2, reg

#endif

arch/x86/entry/entry_32.S

+0 −18
Original line number Diff line number Diff line
@@ -1233,24 +1233,6 @@ SYM_FUNC_END(entry_INT80_32) 
#endif

.endm



#define BUILD_INTERRUPT3(name, nr, fn)			\

SYM_FUNC_START(name)					\

	ASM_CLAC;					\

	pushl	$~(nr);					\

	SAVE_ALL switch_stacks=1;			\

	ENCODE_FRAME_POINTER;				\

	TRACE_IRQS_OFF					\

	movl	%esp, %eax;				\

	call	fn;					\

	jmp	ret_from_intr;				\

SYM_FUNC_END(name)



#define BUILD_INTERRUPT(name, nr)		\

	BUILD_INTERRUPT3(name, nr, smp_##name);	\



/* The include is where all of the SMP etc. interrupts come from */

#include <asm/entry_arch.h>



#ifdef CONFIG_PARAVIRT

SYM_CODE_START(native_iret)

	iret

arch/x86/entry/entry_64.S

+0 −143
Original line number Diff line number Diff line
@@ -658,108 +658,7 @@ SYM_CODE_END(\asmsym) 
 */

#include <asm/idtentry.h>



/*

 * Interrupt entry helper function.

 *

 * Entry runs with interrupts off. Stack layout at entry:

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

 * | regs->ss						|

 * | regs->rsp						|

 * | regs->eflags					|

 * | regs->cs						|

 * | regs->ip						|

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

 * | regs->orig_ax = ~(interrupt number)		|

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

 * | return address					|

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

 */

SYM_CODE_START(interrupt_entry)

	UNWIND_HINT_IRET_REGS offset=16

	ASM_CLAC

	cld



	testb	$3, CS-ORIG_RAX+8(%rsp)

	jz	1f

	SWAPGS

	FENCE_SWAPGS_USER_ENTRY

	/*

	 * Switch to the thread stack. The IRET frame and orig_ax are

	 * on the stack, as well as the return address. RDI..R12 are

	 * not (yet) on the stack and space has not (yet) been

	 * allocated for them.

	 */

	pushq	%rdi



	/* Need to switch before accessing the thread stack. */

	SWITCH_TO_KERNEL_CR3 scratch_reg=%rdi

	movq	%rsp, %rdi

	movq	PER_CPU_VAR(cpu_current_top_of_stack), %rsp



	 /*

	  * We have RDI, return address, and orig_ax on the stack on

	  * top of the IRET frame. That means offset=24

	  */

	UNWIND_HINT_IRET_REGS base=%rdi offset=24



	pushq	7*8(%rdi)		/* regs->ss */

	pushq	6*8(%rdi)		/* regs->rsp */

	pushq	5*8(%rdi)		/* regs->eflags */

	pushq	4*8(%rdi)		/* regs->cs */

	pushq	3*8(%rdi)		/* regs->ip */

	UNWIND_HINT_IRET_REGS

	pushq	2*8(%rdi)		/* regs->orig_ax */

	pushq	8(%rdi)			/* return address */



	movq	(%rdi), %rdi

	jmp	2f

1:

	FENCE_SWAPGS_KERNEL_ENTRY

2:

	PUSH_AND_CLEAR_REGS save_ret=1

	ENCODE_FRAME_POINTER 8



	testb	$3, CS+8(%rsp)

	jz	1f



	/*

	 * IRQ from user mode.

	 *

	 * We need to tell lockdep that IRQs are off.  We can't do this until

	 * we fix gsbase, and we should do it before enter_from_user_mode

	 * (which can take locks).  Since TRACE_IRQS_OFF is idempotent,

	 * the simplest way to handle it is to just call it twice if

	 * we enter from user mode.  There's no reason to optimize this since

	 * TRACE_IRQS_OFF is a no-op if lockdep is off.

	 */

	TRACE_IRQS_OFF



	CALL_enter_from_user_mode



1:

	ENTER_IRQ_STACK old_rsp=%rdi save_ret=1

	/* We entered an interrupt context - irqs are off: */

	TRACE_IRQS_OFF



	ret

SYM_CODE_END(interrupt_entry)

_ASM_NOKPROBE(interrupt_entry)



SYM_CODE_START_LOCAL(common_interrupt_return)

ret_from_intr:

	DISABLE_INTERRUPTS(CLBR_ANY)

	TRACE_IRQS_OFF



	LEAVE_IRQ_STACK



	testb	$3, CS(%rsp)

	jz	retint_kernel



	/* Interrupt came from user space */

.Lretint_user:

	mov	%rsp,%rdi

	call	prepare_exit_to_usermode



SYM_INNER_LABEL(swapgs_restore_regs_and_return_to_usermode, SYM_L_GLOBAL)

#ifdef CONFIG_DEBUG_ENTRY

	/* Assert that pt_regs indicates user mode. */
@@ -802,23 +701,6 @@ SYM_INNER_LABEL(swapgs_restore_regs_and_return_to_usermode, SYM_L_GLOBAL) 
	INTERRUPT_RETURN





/* Returning to kernel space */

retint_kernel:

#ifdef CONFIG_PREEMPTION

	/* Interrupts are off */

	/* Check if we need preemption */

	btl	$9, EFLAGS(%rsp)		/* were interrupts off? */

	jnc	1f

	cmpl	$0, PER_CPU_VAR(__preempt_count)

	jnz	1f

	call	preempt_schedule_irq

1:

#endif

	/*

	 * The iretq could re-enable interrupts:

	 */

	TRACE_IRQS_IRETQ



SYM_INNER_LABEL(restore_regs_and_return_to_kernel, SYM_L_GLOBAL)

#ifdef CONFIG_DEBUG_ENTRY

	/* Assert that pt_regs indicates kernel mode. */
@@ -931,31 +813,6 @@ native_irq_return_ldt: 
SYM_CODE_END(common_interrupt_return)

_ASM_NOKPROBE(common_interrupt_return)



/*

 * APIC interrupts.

 */

.macro apicinterrupt3 num sym do_sym

SYM_CODE_START(\sym)

	UNWIND_HINT_IRET_REGS

	pushq	$~(\num)

	call	interrupt_entry

	UNWIND_HINT_REGS indirect=1

	call	\do_sym	/* rdi points to pt_regs */

	jmp	ret_from_intr

SYM_CODE_END(\sym)

_ASM_NOKPROBE(\sym)

.endm



/* Make sure APIC interrupt handlers end up in the irqentry section: */

#define PUSH_SECTION_IRQENTRY	.pushsection .irqentry.text, "ax"

#define POP_SECTION_IRQENTRY	.popsection



.macro apicinterrupt num sym do_sym

PUSH_SECTION_IRQENTRY

apicinterrupt3 \num \sym \do_sym

POP_SECTION_IRQENTRY

.endm



/*

 * Reload gs selector with exception handling

 * edi:  new selector

arch/x86/include/asm/entry_arch.h

deleted100644 → 0
+0 −12
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

/*

 * This file is designed to contain the BUILD_INTERRUPT specifications for

 * all of the extra named interrupt vectors used by the architecture.

 * Usually this is the Inter Process Interrupts (IPIs)

 */



/*

 * The following vectors are part of the Linux architecture, there

 * is no hardware IRQ pin equivalent for them, they are triggered

 * through the ICC by us (IPIs)

 */

arch/x86/kernel/head_64.S

+4 −3
Original line number Diff line number Diff line
@@ -29,15 +29,16 @@ 
#ifdef CONFIG_PARAVIRT_XXL

#include <asm/asm-offsets.h>

#include <asm/paravirt.h>

#define GET_CR2_INTO(reg) GET_CR2_INTO_AX ; _ASM_MOV %_ASM_AX, reg

#else

#define INTERRUPT_RETURN iretq

#define GET_CR2_INTO(reg) _ASM_MOV %cr2, reg

#endif



/* we are not able to switch in one step to the final KERNEL ADDRESS SPACE

/*

 * We are not able to switch in one step to the final KERNEL ADDRESS SPACE

 * because we need identity-mapped pages.

 *

 */



#define l4_index(x)	(((x) >> 39) & 511)

#define pud_index(x)	(((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1))