Commit 3d82c59c authored by Steven Rostedt (VMware)'s avatar Steven Rostedt (VMware) Committed by Thomas Gleixner
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x86/ftrace: Move the ftrace specific code out of entry_32.S 



The function tracing hook code for ftrace is not an entry point from
userspace and does not belong in the entry_*.S files. It has already been
moved out of entry_64.S.

Move it out of entry_32.S into its own ftrace_32.S file.

Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20170323143445.645218946@goodmis.org


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent db65d7b6

arch/x86/entry/entry_32.S

+0 −169
Original line number Diff line number Diff line
@@ -35,16 +35,13 @@ 
#include <asm/errno.h>

#include <asm/segment.h>

#include <asm/smp.h>

#include <asm/page_types.h>

#include <asm/percpu.h>

#include <asm/processor-flags.h>

#include <asm/ftrace.h>

#include <asm/irq_vectors.h>

#include <asm/cpufeatures.h>

#include <asm/alternative-asm.h>

#include <asm/asm.h>

#include <asm/smap.h>

#include <asm/export.h>

#include <asm/frame.h>



	.section .entry.text, "ax"
@@ -886,172 +883,6 @@ BUILD_INTERRUPT3(hyperv_callback_vector, HYPERVISOR_CALLBACK_VECTOR, 


#endif /* CONFIG_HYPERV */



#ifdef CONFIG_FUNCTION_TRACER

#ifdef CONFIG_DYNAMIC_FTRACE



ENTRY(mcount)

	ret

END(mcount)



ENTRY(ftrace_caller)

	pushl	%eax

	pushl	%ecx

	pushl	%edx

	pushl	$0				/* Pass NULL as regs pointer */

	movl	4*4(%esp), %eax

	movl	0x4(%ebp), %edx

	movl	function_trace_op, %ecx

	subl	$MCOUNT_INSN_SIZE, %eax



.globl ftrace_call

ftrace_call:

	call	ftrace_stub



	addl	$4, %esp			/* skip NULL pointer */

	popl	%edx

	popl	%ecx

	popl	%eax

.Lftrace_ret:

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

.globl ftrace_graph_call

ftrace_graph_call:

	jmp	ftrace_stub

#endif



/* This is weak to keep gas from relaxing the jumps */

WEAK(ftrace_stub)

	ret

END(ftrace_caller)



ENTRY(ftrace_regs_caller)

	pushf	/* push flags before compare (in cs location) */



	/*

	 * i386 does not save SS and ESP when coming from kernel.

	 * Instead, to get sp, &regs->sp is used (see ptrace.h).

	 * Unfortunately, that means eflags must be at the same location

	 * as the current return ip is. We move the return ip into the

	 * ip location, and move flags into the return ip location.

	 */

	pushl	4(%esp)				/* save return ip into ip slot */



	pushl	$0				/* Load 0 into orig_ax */

	pushl	%gs

	pushl	%fs

	pushl	%es

	pushl	%ds

	pushl	%eax

	pushl	%ebp

	pushl	%edi

	pushl	%esi

	pushl	%edx

	pushl	%ecx

	pushl	%ebx



	movl	13*4(%esp), %eax		/* Get the saved flags */

	movl	%eax, 14*4(%esp)		/* Move saved flags into regs->flags location */

						/* clobbering return ip */

	movl	$__KERNEL_CS, 13*4(%esp)



	movl	12*4(%esp), %eax		/* Load ip (1st parameter) */

	subl	$MCOUNT_INSN_SIZE, %eax		/* Adjust ip */

	movl	0x4(%ebp), %edx			/* Load parent ip (2nd parameter) */

	movl	function_trace_op, %ecx		/* Save ftrace_pos in 3rd parameter */

	pushl	%esp				/* Save pt_regs as 4th parameter */



GLOBAL(ftrace_regs_call)

	call	ftrace_stub



	addl	$4, %esp			/* Skip pt_regs */

	movl	14*4(%esp), %eax		/* Move flags back into cs */

	movl	%eax, 13*4(%esp)		/* Needed to keep addl	from modifying flags */

	movl	12*4(%esp), %eax		/* Get return ip from regs->ip */

	movl	%eax, 14*4(%esp)		/* Put return ip back for ret */



	popl	%ebx

	popl	%ecx

	popl	%edx

	popl	%esi

	popl	%edi

	popl	%ebp

	popl	%eax

	popl	%ds

	popl	%es

	popl	%fs

	popl	%gs

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

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

	jmp	.Lftrace_ret



	popf

	jmp	ftrace_stub

#else /* ! CONFIG_DYNAMIC_FTRACE */



ENTRY(mcount)

	cmpl	$__PAGE_OFFSET, %esp

	jb	ftrace_stub			/* Paging not enabled yet? */



	cmpl	$ftrace_stub, ftrace_trace_function

	jnz	.Ltrace

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

	cmpl	$ftrace_stub, ftrace_graph_return

	jnz	ftrace_graph_caller



	cmpl	$ftrace_graph_entry_stub, ftrace_graph_entry

	jnz	ftrace_graph_caller

#endif

.globl ftrace_stub

ftrace_stub:

	ret



	/* taken from glibc */

.Ltrace:

	pushl	%eax

	pushl	%ecx

	pushl	%edx

	movl	0xc(%esp), %eax

	movl	0x4(%ebp), %edx

	subl	$MCOUNT_INSN_SIZE, %eax



	call	*ftrace_trace_function



	popl	%edx

	popl	%ecx

	popl	%eax

	jmp	ftrace_stub

END(mcount)

#endif /* CONFIG_DYNAMIC_FTRACE */

EXPORT_SYMBOL(mcount)

#endif /* CONFIG_FUNCTION_TRACER */



#ifdef CONFIG_FUNCTION_GRAPH_TRACER

ENTRY(ftrace_graph_caller)

	pushl	%eax

	pushl	%ecx

	pushl	%edx

	movl	0xc(%esp), %eax

	lea	0x4(%ebp), %edx

	movl	(%ebp), %ecx

	subl	$MCOUNT_INSN_SIZE, %eax

	call	prepare_ftrace_return

	popl	%edx

	popl	%ecx

	popl	%eax

	ret

END(ftrace_graph_caller)



.globl return_to_handler

return_to_handler:

	pushl	%eax

	pushl	%edx

	movl	%ebp, %eax

	call	ftrace_return_to_handler

	movl	%eax, %ecx

	popl	%edx

	popl	%eax

	jmp	*%ecx

#endif



#ifdef CONFIG_TRACING

ENTRY(trace_page_fault)

	ASM_CLAC

arch/x86/kernel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o 
obj-$(CONFIG_IRQ_WORK)  += irq_work.o

obj-y			+= probe_roms.o

obj-$(CONFIG_X86_64)	+= sys_x86_64.o ftrace_64.o

obj-$(CONFIG_X86_32)	+= ftrace_32.o

obj-$(CONFIG_X86_ESPFIX64)	+= espfix_64.o

obj-$(CONFIG_SYSFS)	+= ksysfs.o

obj-y			+= bootflag.o e820.o

arch/x86/kernel/ftrace_32.S

0 → 100644
+175 −0
Original line number Diff line number Diff line 
/*

 *  Copyright (C) 2017  Steven Rostedt, VMware Inc.

 */



#include <linux/linkage.h>

#include <asm/page_types.h>

#include <asm/segment.h>

#include <asm/export.h>

#include <asm/ftrace.h>



#ifdef CONFIG_FUNCTION_TRACER

#ifdef CONFIG_DYNAMIC_FTRACE



ENTRY(mcount)

	ret

END(mcount)



ENTRY(ftrace_caller)

	pushl	%eax

	pushl	%ecx

	pushl	%edx

	pushl	$0				/* Pass NULL as regs pointer */

	movl	4*4(%esp), %eax

	movl	0x4(%ebp), %edx

	movl	function_trace_op, %ecx

	subl	$MCOUNT_INSN_SIZE, %eax



.globl ftrace_call

ftrace_call:

	call	ftrace_stub



	addl	$4, %esp			/* skip NULL pointer */

	popl	%edx

	popl	%ecx

	popl	%eax

.Lftrace_ret:

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

.globl ftrace_graph_call

ftrace_graph_call:

	jmp	ftrace_stub

#endif



/* This is weak to keep gas from relaxing the jumps */

WEAK(ftrace_stub)

	ret

END(ftrace_caller)



ENTRY(ftrace_regs_caller)

	pushf	/* push flags before compare (in cs location) */



	/*

	 * i386 does not save SS and ESP when coming from kernel.

	 * Instead, to get sp, &regs->sp is used (see ptrace.h).

	 * Unfortunately, that means eflags must be at the same location

	 * as the current return ip is. We move the return ip into the

	 * ip location, and move flags into the return ip location.

	 */

	pushl	4(%esp)				/* save return ip into ip slot */



	pushl	$0				/* Load 0 into orig_ax */

	pushl	%gs

	pushl	%fs

	pushl	%es

	pushl	%ds

	pushl	%eax

	pushl	%ebp

	pushl	%edi

	pushl	%esi

	pushl	%edx

	pushl	%ecx

	pushl	%ebx



	movl	13*4(%esp), %eax		/* Get the saved flags */

	movl	%eax, 14*4(%esp)		/* Move saved flags into regs->flags location */

						/* clobbering return ip */

	movl	$__KERNEL_CS, 13*4(%esp)



	movl	12*4(%esp), %eax		/* Load ip (1st parameter) */

	subl	$MCOUNT_INSN_SIZE, %eax		/* Adjust ip */

	movl	0x4(%ebp), %edx			/* Load parent ip (2nd parameter) */

	movl	function_trace_op, %ecx		/* Save ftrace_pos in 3rd parameter */

	pushl	%esp				/* Save pt_regs as 4th parameter */



GLOBAL(ftrace_regs_call)

	call	ftrace_stub



	addl	$4, %esp			/* Skip pt_regs */

	movl	14*4(%esp), %eax		/* Move flags back into cs */

	movl	%eax, 13*4(%esp)		/* Needed to keep addl	from modifying flags */

	movl	12*4(%esp), %eax		/* Get return ip from regs->ip */

	movl	%eax, 14*4(%esp)		/* Put return ip back for ret */



	popl	%ebx

	popl	%ecx

	popl	%edx

	popl	%esi

	popl	%edi

	popl	%ebp

	popl	%eax

	popl	%ds

	popl	%es

	popl	%fs

	popl	%gs

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

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

	jmp	.Lftrace_ret



	popf

	jmp	ftrace_stub

#else /* ! CONFIG_DYNAMIC_FTRACE */



ENTRY(mcount)

	cmpl	$__PAGE_OFFSET, %esp

	jb	ftrace_stub			/* Paging not enabled yet? */



	cmpl	$ftrace_stub, ftrace_trace_function

	jnz	.Ltrace

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

	cmpl	$ftrace_stub, ftrace_graph_return

	jnz	ftrace_graph_caller



	cmpl	$ftrace_graph_entry_stub, ftrace_graph_entry

	jnz	ftrace_graph_caller

#endif

.globl ftrace_stub

ftrace_stub:

	ret



	/* taken from glibc */

.Ltrace:

	pushl	%eax

	pushl	%ecx

	pushl	%edx

	movl	0xc(%esp), %eax

	movl	0x4(%ebp), %edx

	subl	$MCOUNT_INSN_SIZE, %eax



	call	*ftrace_trace_function



	popl	%edx

	popl	%ecx

	popl	%eax

	jmp	ftrace_stub

END(mcount)

#endif /* CONFIG_DYNAMIC_FTRACE */

EXPORT_SYMBOL(mcount)

#endif /* CONFIG_FUNCTION_TRACER */



#ifdef CONFIG_FUNCTION_GRAPH_TRACER

ENTRY(ftrace_graph_caller)

	pushl	%eax

	pushl	%ecx

	pushl	%edx

	movl	0xc(%esp), %eax

	lea	0x4(%ebp), %edx

	movl	(%ebp), %ecx

	subl	$MCOUNT_INSN_SIZE, %eax

	call	prepare_ftrace_return

	popl	%edx

	popl	%ecx

	popl	%eax

	ret

END(ftrace_graph_caller)



.globl return_to_handler

return_to_handler:

	pushl	%eax

	pushl	%edx

	movl	%ebp, %eax

	call	ftrace_return_to_handler

	movl	%eax, %ecx

	popl	%edx

	popl	%eax

	jmp	*%ecx

#endif

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