Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 193 insertions, 0 deletions

diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S
new file mode 100644
index 000000000..a0ed0e4a2
--- /dev/null
+++ b/arch/x86/kernel/ftrace_32.S
@@ -0,0 +1,193 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  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>
+#include <asm/nospec-branch.h>
+#include <asm/frame.h>
+#include <asm/asm-offsets.h>
+
+#ifdef CONFIG_FRAME_POINTER
+# define MCOUNT_FRAME			1	/* using frame = true  */
+#else
+# define MCOUNT_FRAME			0	/* using frame = false */
+#endif
+
+SYM_FUNC_START(__fentry__)
+	RET
+SYM_FUNC_END(__fentry__)
+EXPORT_SYMBOL(__fentry__)
+
+SYM_CODE_START(ftrace_caller)
+
+#ifdef CONFIG_FRAME_POINTER
+	/*
+	 * Frame pointers are of ip followed by bp.
+	 * Since fentry is an immediate jump, we are left with
+	 * parent-ip, function-ip. We need to add a frame with
+	 * parent-ip followed by ebp.
+	 */
+	pushl	4(%esp)				/* parent ip */
+	pushl	%ebp
+	movl	%esp, %ebp
+	pushl	2*4(%esp)			/* function ip */
+
+	/* For mcount, the function ip is directly above */
+	pushl	%ebp
+	movl	%esp, %ebp
+#endif
+	pushl	%eax
+	pushl	%ecx
+	pushl	%edx
+	pushl	$0				/* Pass NULL as regs pointer */
+
+#ifdef CONFIG_FRAME_POINTER
+	/* Load parent ebp into edx */
+	movl	4*4(%esp), %edx
+#else
+	/* There's no frame pointer, load the appropriate stack addr instead */
+	lea	4*4(%esp), %edx
+#endif
+
+	movl	(MCOUNT_FRAME+4)*4(%esp), %eax	/* load the rip */
+	/* Get the parent ip */
+	movl	4(%edx), %edx			/* edx has ebp */
+
+	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
+#ifdef CONFIG_FRAME_POINTER
+	popl	%ebp
+	addl	$4,%esp				/* skip function ip */
+	popl	%ebp				/* this is the orig bp */
+	addl	$4, %esp			/* skip parent ip */
+#endif
+.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 */
+SYM_INNER_LABEL_ALIGN(ftrace_stub, SYM_L_WEAK)
+	RET
+SYM_CODE_END(ftrace_caller)
+
+SYM_CODE_START(ftrace_regs_caller)
+	/*
+	 * We're here from an mcount/fentry CALL, and the stack frame looks like:
+	 *
+	 *  <previous context>
+	 *  RET-IP
+	 *
+	 * The purpose of this function is to call out in an emulated INT3
+	 * environment with a stack frame like:
+	 *
+	 *  <previous context>
+	 *  gap / RET-IP
+	 *  gap
+	 *  gap
+	 *  gap
+	 *  pt_regs
+	 *
+	 * We do _NOT_ restore: ss, flags, cs, gs, fs, es, ds
+	 */
+	subl	$3*4, %esp	# RET-IP + 3 gaps
+	pushl	%ss		# ss
+	pushl	%esp		# points at ss
+	addl	$5*4, (%esp)	#   make it point at <previous context>
+	pushfl			# flags
+	pushl	$__KERNEL_CS	# cs
+	pushl	7*4(%esp)	# ip <- RET-IP
+	pushl	$0		# orig_eax
+
+	pushl	%gs
+	pushl	%fs
+	pushl	%es
+	pushl	%ds
+
+	pushl	%eax
+	pushl	%ebp
+	pushl	%edi
+	pushl	%esi
+	pushl	%edx
+	pushl	%ecx
+	pushl	%ebx
+
+	ENCODE_FRAME_POINTER
+
+	movl	PT_EIP(%esp), %eax	# 1st argument: IP
+	subl	$MCOUNT_INSN_SIZE, %eax
+	movl	21*4(%esp), %edx	# 2nd argument: parent ip
+	movl	function_trace_op, %ecx	# 3rd argument: ftrace_pos
+	pushl	%esp			# 4th argument: pt_regs
+
+SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL)
+	call	ftrace_stub
+
+	addl	$4, %esp		# skip 4th argument
+
+	/* place IP below the new SP */
+	movl	PT_OLDESP(%esp), %eax
+	movl	PT_EIP(%esp), %ecx
+	movl	%ecx, -4(%eax)
+
+	/* place EAX below that */
+	movl	PT_EAX(%esp), %ecx
+	movl	%ecx, -8(%eax)
+
+	popl	%ebx
+	popl	%ecx
+	popl	%edx
+	popl	%esi
+	popl	%edi
+	popl	%ebp
+
+	lea	-8(%eax), %esp
+	popl	%eax
+
+	jmp	.Lftrace_ret
+SYM_CODE_END(ftrace_regs_caller)
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+SYM_CODE_START(ftrace_graph_caller)
+	pushl	%eax
+	pushl	%ecx
+	pushl	%edx
+	movl	3*4(%esp), %eax
+	/* Even with frame pointers, fentry doesn't have one here */
+	lea	4*4(%esp), %edx
+	movl	$0, %ecx
+	subl	$MCOUNT_INSN_SIZE, %eax
+	call	prepare_ftrace_return
+	popl	%edx
+	popl	%ecx
+	popl	%eax
+	RET
+SYM_CODE_END(ftrace_graph_caller)
+
+.globl return_to_handler
+return_to_handler:
+	pushl	%eax
+	pushl	%edx
+	movl	$0, %eax
+	call	ftrace_return_to_handler
+	movl	%eax, %ecx
+	popl	%edx
+	popl	%eax
+	JMP_NOSPEC ecx
+#endif