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[PATCH 2/6 v5] ftrace/x86_32: Move the ftrace specific code out of entry_32.S

Started bySteven Rostedt <rostedt@goodmis.org>
First post2017-03-23 15:40 +0100
Last post2017-03-24 10:30 +0100
Articles 4 — 3 participants

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  [PATCH 2/6 v5] ftrace/x86_32: Move the ftrace specific code out of entry_32.S Steven Rostedt <rostedt@goodmis.org> - 2017-03-23 15:40 +0100
    Re: [PATCH 2/6 v5] ftrace/x86_32: Move the ftrace specific code out  of entry_32.S Thomas Gleixner <tglx@linutronix.de> - 2017-03-23 19:20 +0100
      Re: [PATCH 2/6 v5] ftrace/x86_32: Move the ftrace specific code out  of entry_32.S Steven Rostedt <rostedt@goodmis.org> - 2017-03-23 20:10 +0100
    [tip:x86/asm] x86/ftrace: Move the ftrace specific code out of  entry_32.S "tip-bot for Steven Rostedt (VMware)" <tipbot@zytor.com> - 2017-03-24 10:30 +0100

#1607556 — [PATCH 2/6 v5] ftrace/x86_32: Move the ftrace specific code out of entry_32.S

FromSteven Rostedt <rostedt@goodmis.org>
Date2017-03-23 15:40 +0100
Subject[PATCH 2/6 v5] ftrace/x86_32: Move the ftrace specific code out of entry_32.S
Message-ID<toc4b-3pL-35@gated-at.bofh.it>
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

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. This moves it out of entry_32.S into its own
ftrace_32.S file.

Also updated the comment in ftrace_64.S to state the correct file name.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 arch/x86/entry/entry_32.S   | 169 ------------------------------------------
 arch/x86/kernel/Makefile    |   1 +
 arch/x86/kernel/ftrace_32.S | 177 ++++++++++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/ftrace_64.S |   2 +-
 4 files changed, 179 insertions(+), 170 deletions(-)
 create mode 100644 arch/x86/kernel/ftrace_32.S

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 57f7ec35216e..169b3b0c5ec6 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -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	$MCOUNT_INSN_SIZE, %eax
-	call	prepare_ftrace_return
-	popl	%edx
-	popl	%ecx
-	popl	%eax
-	ret
-END(ftrace_graph_caller)
-
-.globl return_to_handler
-return_to_handler:
-	pushl	%eax
-	pushl	%edx
-	movl	%ebp, %eax
-	call	ftrace_return_to_handler
-	movl	%eax, %ecx
-	popl	%edx
-	popl	%eax
-	jmp	*%ecx
-#endif
-
 #ifdef CONFIG_TRACING
 ENTRY(trace_page_fault)
 	ASM_CLAC
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index d3743a37e990..55e8902c461f 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -47,6 +47,7 @@ obj-y			+= setup.o x86_init.o i8259.o irqinit.o jump_label.o
 obj-$(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
diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S
new file mode 100644
index 000000000000..f380604514e4
--- /dev/null
+++ b/arch/x86/kernel/ftrace_32.S
@@ -0,0 +1,177 @@
+/*
+ *  linux/arch/x86_64/ftrace_32.S
+ *
+ *  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
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index 7b0d3da52fb4..fc0fe0e6c2de 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -1,5 +1,5 @@
 /*
- *  linux/arch/x86_64/mcount_64.S
+ *  linux/arch/x86_64/ftrace_64.S
  *
  *  Copyright (C) 2014  Steven Rostedt, Red Hat Inc
  */
-- 
2.10.2

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#1607766 — Re: [PATCH 2/6 v5] ftrace/x86_32: Move the ftrace specific code out of entry_32.S

FromThomas Gleixner <tglx@linutronix.de>
Date2017-03-23 19:20 +0100
SubjectRe: [PATCH 2/6 v5] ftrace/x86_32: Move the ftrace specific code out of entry_32.S
Message-ID<tofv4-615-15@gated-at.bofh.it>
In reply to#1607556
On Thu, 23 Mar 2017, Steven Rostedt wrote:
> --- a/arch/x86/kernel/ftrace_64.S
> +++ b/arch/x86/kernel/ftrace_64.S
> @@ -1,5 +1,5 @@
>  /*
> - *  linux/arch/x86_64/mcount_64.S
> + *  linux/arch/x86_64/ftrace_64.S

Can we please get rid of that nonsense completely?

>   *
>   *  Copyright (C) 2014  Steven Rostedt, Red Hat Inc
>   */
> -- 
> 2.10.2
> 
> 
>

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#1607816 — Re: [PATCH 2/6 v5] ftrace/x86_32: Move the ftrace specific code out of entry_32.S

FromSteven Rostedt <rostedt@goodmis.org>
Date2017-03-23 20:10 +0100
SubjectRe: [PATCH 2/6 v5] ftrace/x86_32: Move the ftrace specific code out of entry_32.S
Message-ID<toghs-6GO-25@gated-at.bofh.it>
In reply to#1607766
On Thu, 23 Mar 2017 19:19:36 +0100 (CET)
Thomas Gleixner <tglx@linutronix.de> wrote:

> On Thu, 23 Mar 2017, Steven Rostedt wrote:
> > --- a/arch/x86/kernel/ftrace_64.S
> > +++ b/arch/x86/kernel/ftrace_64.S
> > @@ -1,5 +1,5 @@
> >  /*
> > - *  linux/arch/x86_64/mcount_64.S
> > + *  linux/arch/x86_64/ftrace_64.S  
> 
> Can we please get rid of that nonsense completely?

Sure.

I'll have a v6 ready in a bit.

-- Steve

> 
> >   *
> >   *  Copyright (C) 2014  Steven Rostedt, Red Hat Inc
> >   */
> > -- 
> > 2.10.2
> > 
> > 
> >

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#1608267 — [tip:x86/asm] x86/ftrace: Move the ftrace specific code out of entry_32.S

From"tip-bot for Steven Rostedt (VMware)" <tipbot@zytor.com>
Date2017-03-24 10:30 +0100
Subject[tip:x86/asm] x86/ftrace: Move the ftrace specific code out of entry_32.S
Message-ID<totHH-7Sh-17@gated-at.bofh.it>
In reply to#1607556
Commit-ID:  3d82c59c6e3cb168284d9b0a1143415d9c98ae40
Gitweb:     http://git.kernel.org/tip/3d82c59c6e3cb168284d9b0a1143415d9c98ae40
Author:     Steven Rostedt (VMware) <rostedt@goodmis.org>
AuthorDate: Thu, 23 Mar 2017 10:33:49 -0400
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Fri, 24 Mar 2017 10:14:07 +0100

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: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Ingo 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: Thomas Gleixner <tglx@linutronix.de>

---
 arch/x86/entry/entry_32.S   | 169 ------------------------------------------
 arch/x86/kernel/Makefile    |   1 +
 arch/x86/kernel/ftrace_32.S | 175 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 176 insertions(+), 169 deletions(-)

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 5553475..50bc269 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -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	$MCOUNT_INSN_SIZE, %eax
-	call	prepare_ftrace_return
-	popl	%edx
-	popl	%ecx
-	popl	%eax
-	ret
-END(ftrace_graph_caller)
-
-.globl return_to_handler
-return_to_handler:
-	pushl	%eax
-	pushl	%edx
-	movl	%ebp, %eax
-	call	ftrace_return_to_handler
-	movl	%eax, %ecx
-	popl	%edx
-	popl	%eax
-	jmp	*%ecx
-#endif
-
 #ifdef CONFIG_TRACING
 ENTRY(trace_page_fault)
 	ASM_CLAC
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index d3743a37..55e8902 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -47,6 +47,7 @@ obj-y			+= setup.o x86_init.o i8259.o irqinit.o jump_label.o
 obj-$(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
diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S
new file mode 100644
index 0000000..2b160f2
--- /dev/null
+++ b/arch/x86/kernel/ftrace_32.S
@@ -0,0 +1,175 @@
+/*
+ *  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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