Commit f6f64681 authored by Denys Vlasenko's avatar Denys Vlasenko Committed by Andy Lutomirski
Browse files

x86: entry_64.S: fold SAVE_ARGS_IRQ macro into its sole user 



No code changes.

This is a preparatory patch for change in "struct pt_regs" handling.

CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Oleg Nesterov <oleg@redhat.com>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: X86 ML <x86@kernel.org>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: linux-kernel@vger.kernel.org
Signed-off-by: default avatarDenys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: default avatarAndy Lutomirski <luto@amacapital.net>
parent 6c3176a2

arch/x86/kernel/entry_64.S

+42 −46
Original line number Diff line number Diff line
@@ -217,51 +217,6 @@ ENDPROC(native_usergs_sysret64) 
	CFI_REL_OFFSET r15, R15+\offset

	.endm



/* save partial stack frame */

	.macro SAVE_ARGS_IRQ

	cld

	/* start from rbp in pt_regs and jump over */

	movq_cfi rdi, (RDI-RBP)

	movq_cfi rsi, (RSI-RBP)

	movq_cfi rdx, (RDX-RBP)

	movq_cfi rcx, (RCX-RBP)

	movq_cfi rax, (RAX-RBP)

	movq_cfi  r8,  (R8-RBP)

	movq_cfi  r9,  (R9-RBP)

	movq_cfi r10, (R10-RBP)

	movq_cfi r11, (R11-RBP)



	/* Save rbp so that we can unwind from get_irq_regs() */

	movq_cfi rbp, 0



	/* Save previous stack value */

	movq %rsp, %rsi



	leaq -RBP(%rsp),%rdi	/* arg1 for handler */

	testl $3, CS-RBP(%rsi)

	je 1f

	SWAPGS

	/*

	 * irq_count is used to check if a CPU is already on an interrupt stack

	 * or not. While this is essentially redundant with preempt_count it is

	 * a little cheaper to use a separate counter in the PDA (short of

	 * moving irq_enter into assembly, which would be too much work)

	 */

1:	incl PER_CPU_VAR(irq_count)

	cmovzq PER_CPU_VAR(irq_stack_ptr),%rsp

	CFI_DEF_CFA_REGISTER	rsi



	/* Store previous stack value */

	pushq %rsi

	CFI_ESCAPE	0x0f /* DW_CFA_def_cfa_expression */, 6, \

			0x77 /* DW_OP_breg7 */, 0, \

			0x06 /* DW_OP_deref */, \

			0x08 /* DW_OP_const1u */, SS+8-RBP, \

			0x22 /* DW_OP_plus */

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

	TRACE_IRQS_OFF

	.endm



ENTRY(save_paranoid)

	XCPT_FRAME 1 RDI+8

	cld
@@ -745,7 +700,48 @@ END(interrupt) 
	/* reserve pt_regs for scratch regs and rbp */

	subq $ORIG_RAX-RBP, %rsp

	CFI_ADJUST_CFA_OFFSET ORIG_RAX-RBP

	SAVE_ARGS_IRQ

	cld

	/* start from rbp in pt_regs and jump over */

	movq_cfi rdi, (RDI-RBP)

	movq_cfi rsi, (RSI-RBP)

	movq_cfi rdx, (RDX-RBP)

	movq_cfi rcx, (RCX-RBP)

	movq_cfi rax, (RAX-RBP)

	movq_cfi  r8,  (R8-RBP)

	movq_cfi  r9,  (R9-RBP)

	movq_cfi r10, (R10-RBP)

	movq_cfi r11, (R11-RBP)



	/* Save rbp so that we can unwind from get_irq_regs() */

	movq_cfi rbp, 0



	/* Save previous stack value */

	movq %rsp, %rsi



	leaq -RBP(%rsp),%rdi	/* arg1 for handler */

	testl $3, CS-RBP(%rsi)

	je 1f

	SWAPGS

	/*

	 * irq_count is used to check if a CPU is already on an interrupt stack

	 * or not. While this is essentially redundant with preempt_count it is

	 * a little cheaper to use a separate counter in the PDA (short of

	 * moving irq_enter into assembly, which would be too much work)

	 */

1:	incl PER_CPU_VAR(irq_count)

	cmovzq PER_CPU_VAR(irq_stack_ptr),%rsp

	CFI_DEF_CFA_REGISTER	rsi



	/* Store previous stack value */

	pushq %rsi

	CFI_ESCAPE	0x0f /* DW_CFA_def_cfa_expression */, 6, \

			0x77 /* DW_OP_breg7 */, 0, \

			0x06 /* DW_OP_deref */, \

			0x08 /* DW_OP_const1u */, SS+8-RBP, \

			0x22 /* DW_OP_plus */

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

	TRACE_IRQS_OFF



	call \func

	.endm

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