Merge tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "There was a lot of clean ups and minor fixes.  One of those clean ups
  was to the trace_seq code.  It also removed the return values to the
  trace_seq_*() functions and use trace_seq_has_overflowed() to see if
  the buffer filled up or not.  This is similar to work being done to
  the seq_file code as well in another tree.

  Some of the other goodies include:

   - Added some "!" (NOT) logic to the tracing filter.

   - Fixed the frame pointer logic to the x86_64 mcount trampolines

   - Added the logic for dynamic trampolines on !CONFIG_PREEMPT systems.
     That is, the ftrace trampoline can be dynamically allocated and be
     called directly by functions that only have a single hook to them"

* tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (55 commits)
  tracing: Truncated output is better than nothing
  tracing: Add additional marks to signal very large time deltas
  Documentation: describe trace_buf_size parameter more accurately
  tracing: Allow NOT to filter AND and OR clauses
  tracing: Add NOT to filtering logic
  ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter
  ftrace/x86: Get rid of ftrace_caller_setup
  ftrace/x86: Have save_mcount_regs macro also save stack frames if needed
  ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs
  ftrace/x86: Simplify save_mcount_regs on getting RIP
  ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameter
  ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments
  ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file
  ftrace/x86: Have static tracing also use ftrace_caller_setup
  ftrace/x86: Have static function tracing always test for function graph
  kprobes: Add IPMODIFY flag to kprobe_ftrace_ops
  ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict
  kprobes/ftrace: Recover original IP if pre_handler doesn't change it
  tracing/trivial: Fix typos and make an int into a bool
  tracing: Deletion of an unnecessary check before iput()
  ...

5 files changed, 459 insertions, 99 deletions

diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index e1f7fecaa7d..f45acad3c4b 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -1,39 +1,6 @@
 #ifndef _ASM_X86_FTRACE_H
 #define _ASM_X86_FTRACE_H
 
-#ifdef __ASSEMBLY__
-
-	/* skip is set if the stack was already partially adjusted */
-	.macro MCOUNT_SAVE_FRAME skip=0
-	 /*
-	  * We add enough stack to save all regs.
-	  */
-	subq $(SS+8-\skip), %rsp
-	movq %rax, RAX(%rsp)
-	movq %rcx, RCX(%rsp)
-	movq %rdx, RDX(%rsp)
-	movq %rsi, RSI(%rsp)
-	movq %rdi, RDI(%rsp)
-	movq %r8, R8(%rsp)
-	movq %r9, R9(%rsp)
-	 /* Move RIP to its proper location */
-	movq SS+8(%rsp), %rdx
-	movq %rdx, RIP(%rsp)
-	.endm
-
-	.macro MCOUNT_RESTORE_FRAME skip=0
-	movq R9(%rsp), %r9
-	movq R8(%rsp), %r8
-	movq RDI(%rsp), %rdi
-	movq RSI(%rsp), %rsi
-	movq RDX(%rsp), %rdx
-	movq RCX(%rsp), %rcx
-	movq RAX(%rsp), %rax
-	addq $(SS+8-\skip), %rsp
-	.endm
-
-#endif
-
 #ifdef CONFIG_FUNCTION_TRACER
 #ifdef CC_USING_FENTRY
 # define MCOUNT_ADDR		((long)(__fentry__))
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 3386dc9aa33..2142376dc8c 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -17,6 +17,7 @@
 #include <linux/ftrace.h>
 #include <linux/percpu.h>
 #include <linux/sched.h>
+#include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/module.h>
@@ -47,7 +48,7 @@ int ftrace_arch_code_modify_post_process(void)
 union ftrace_code_union {
 	char code[MCOUNT_INSN_SIZE];
 	struct {
-		char e8;
+		unsigned char e8;
 		int offset;
 	} __attribute__((packed));
 };
@@ -582,7 +583,7 @@ void ftrace_replace_code(int enable)
 
  remove_breakpoints:
 	pr_warn("Failed on %s (%d):\n", report, count);
-	ftrace_bug(ret, rec ? rec->ip : 0);
+	ftrace_bug(ret, rec);
 	for_ftrace_rec_iter(iter) {
 		rec = ftrace_rec_iter_record(iter);
 		/*
@@ -644,13 +645,8 @@ int __init ftrace_dyn_arch_init(void)
 {
 	return 0;
 }
-#endif
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-
-#ifdef CONFIG_DYNAMIC_FTRACE
-extern void ftrace_graph_call(void);
 
+#if defined(CONFIG_X86_64) || defined(CONFIG_FUNCTION_GRAPH_TRACER)
 static unsigned char *ftrace_jmp_replace(unsigned long ip, unsigned long addr)
 {
 	static union ftrace_code_union calc;
@@ -664,6 +660,280 @@ static unsigned char *ftrace_jmp_replace(unsigned long ip, unsigned long addr)
 	 */
 	return calc.code;
 }
+#endif
+
+/* Currently only x86_64 supports dynamic trampolines */
+#ifdef CONFIG_X86_64
+
+#ifdef CONFIG_MODULES
+#include <linux/moduleloader.h>
+/* Module allocation simplifies allocating memory for code */
+static inline void *alloc_tramp(unsigned long size)
+{
+	return module_alloc(size);
+}
+static inline void tramp_free(void *tramp)
+{
+	module_free(NULL, tramp);
+}
+#else
+/* Trampolines can only be created if modules are supported */
+static inline void *alloc_tramp(unsigned long size)
+{
+	return NULL;
+}
+static inline void tramp_free(void *tramp) { }
+#endif
+
+/* Defined as markers to the end of the ftrace default trampolines */
+extern void ftrace_caller_end(void);
+extern void ftrace_regs_caller_end(void);
+extern void ftrace_return(void);
+extern void ftrace_caller_op_ptr(void);
+extern void ftrace_regs_caller_op_ptr(void);
+
+/* movq function_trace_op(%rip), %rdx */
+/* 0x48 0x8b 0x15 <offset-to-ftrace_trace_op (4 bytes)> */
+#define OP_REF_SIZE	7
+
+/*
+ * The ftrace_ops is passed to the function callback. Since the
+ * trampoline only services a single ftrace_ops, we can pass in
+ * that ops directly.
+ *
+ * The ftrace_op_code_union is used to create a pointer to the
+ * ftrace_ops that will be passed to the callback function.
+ */
+union ftrace_op_code_union {
+	char code[OP_REF_SIZE];
+	struct {
+		char op[3];
+		int offset;
+	} __attribute__((packed));
+};
+
+static unsigned long
+create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
+{
+	unsigned const char *jmp;
+	unsigned long start_offset;
+	unsigned long end_offset;
+	unsigned long op_offset;
+	unsigned long offset;
+	unsigned long size;
+	unsigned long ip;
+	unsigned long *ptr;
+	void *trampoline;
+	/* 48 8b 15 <offset> is movq <offset>(%rip), %rdx */
+	unsigned const char op_ref[] = { 0x48, 0x8b, 0x15 };
+	union ftrace_op_code_union op_ptr;
+	int ret;
+
+	if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
+		start_offset = (unsigned long)ftrace_regs_caller;
+		end_offset = (unsigned long)ftrace_regs_caller_end;
+		op_offset = (unsigned long)ftrace_regs_caller_op_ptr;
+	} else {
+		start_offset = (unsigned long)ftrace_caller;
+		end_offset = (unsigned long)ftrace_caller_end;
+		op_offset = (unsigned long)ftrace_caller_op_ptr;
+	}
+
+	size = end_offset - start_offset;
+
+	/*
+	 * Allocate enough size to store the ftrace_caller code,
+	 * the jmp to ftrace_return, as well as the address of
+	 * the ftrace_ops this trampoline is used for.
+	 */
+	trampoline = alloc_tramp(size + MCOUNT_INSN_SIZE + sizeof(void *));
+	if (!trampoline)
+		return 0;
+
+	*tramp_size = size + MCOUNT_INSN_SIZE + sizeof(void *);
+
+	/* Copy ftrace_caller onto the trampoline memory */
+	ret = probe_kernel_read(trampoline, (void *)start_offset, size);
+	if (WARN_ON(ret < 0)) {
+		tramp_free(trampoline);
+		return 0;
+	}
+
+	ip = (unsigned long)trampoline + size;
+
+	/* The trampoline ends with a jmp to ftrace_return */
+	jmp = ftrace_jmp_replace(ip, (unsigned long)ftrace_return);
+	memcpy(trampoline + size, jmp, MCOUNT_INSN_SIZE);
+
+	/*
+	 * The address of the ftrace_ops that is used for this trampoline
+	 * is stored at the end of the trampoline. This will be used to
+	 * load the third parameter for the callback. Basically, that
+	 * location at the end of the trampoline takes the place of
+	 * the global function_trace_op variable.
+	 */
+
+	ptr = (unsigned long *)(trampoline + size + MCOUNT_INSN_SIZE);
+	*ptr = (unsigned long)ops;
+
+	op_offset -= start_offset;
+	memcpy(&op_ptr, trampoline + op_offset, OP_REF_SIZE);
+
+	/* Are we pointing to the reference? */
+	if (WARN_ON(memcmp(op_ptr.op, op_ref, 3) != 0)) {
+		tramp_free(trampoline);
+		return 0;
+	}
+
+	/* Load the contents of ptr into the callback parameter */
+	offset = (unsigned long)ptr;
+	offset -= (unsigned long)trampoline + op_offset + OP_REF_SIZE;
+
+	op_ptr.offset = offset;
+
+	/* put in the new offset to the ftrace_ops */
+	memcpy(trampoline + op_offset, &op_ptr, OP_REF_SIZE);
+
+	/* ALLOC_TRAMP flags lets us know we created it */
+	ops->flags |= FTRACE_OPS_FL_ALLOC_TRAMP;
+
+	return (unsigned long)trampoline;
+}
+
+static unsigned long calc_trampoline_call_offset(bool save_regs)
+{
+	unsigned long start_offset;
+	unsigned long call_offset;
+
+	if (save_regs) {
+		start_offset = (unsigned long)ftrace_regs_caller;
+		call_offset = (unsigned long)ftrace_regs_call;
+	} else {
+		start_offset = (unsigned long)ftrace_caller;
+		call_offset = (unsigned long)ftrace_call;
+	}
+
+	return call_offset - start_offset;
+}
+
+void arch_ftrace_update_trampoline(struct ftrace_ops *ops)
+{
+	ftrace_func_t func;
+	unsigned char *new;
+	unsigned long offset;
+	unsigned long ip;
+	unsigned int size;
+	int ret;
+
+	if (ops->trampoline) {
+		/*
+		 * The ftrace_ops caller may set up its own trampoline.
+		 * In such a case, this code must not modify it.
+		 */
+		if (!(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
+			return;
+	} else {
+		ops->trampoline = create_trampoline(ops, &size);
+		if (!ops->trampoline)
+			return;
+		ops->trampoline_size = size;
+	}
+
+	offset = calc_trampoline_call_offset(ops->flags & FTRACE_OPS_FL_SAVE_REGS);
+	ip = ops->trampoline + offset;
+
+	func = ftrace_ops_get_func(ops);
+
+	/* Do a safe modify in case the trampoline is executing */
+	new = ftrace_call_replace(ip, (unsigned long)func);
+	ret = update_ftrace_func(ip, new);
+
+	/* The update should never fail */
+	WARN_ON(ret);
+}
+
+/* Return the address of the function the trampoline calls */
+static void *addr_from_call(void *ptr)
+{
+	union ftrace_code_union calc;
+	int ret;
+
+	ret = probe_kernel_read(&calc, ptr, MCOUNT_INSN_SIZE);
+	if (WARN_ON_ONCE(ret < 0))
+		return NULL;
+
+	/* Make sure this is a call */
+	if (WARN_ON_ONCE(calc.e8 != 0xe8)) {
+		pr_warn("Expected e8, got %x\n", calc.e8);
+		return NULL;
+	}
+
+	return ptr + MCOUNT_INSN_SIZE + calc.offset;
+}
+
+void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
+			   unsigned long frame_pointer);
+
+/*
+ * If the ops->trampoline was not allocated, then it probably
+ * has a static trampoline func, or is the ftrace caller itself.
+ */
+static void *static_tramp_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
+{
+	unsigned long offset;
+	bool save_regs = rec->flags & FTRACE_FL_REGS_EN;
+	void *ptr;
+
+	if (ops && ops->trampoline) {
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+		/*
+		 * We only know about function graph tracer setting as static
+		 * trampoline.
+		 */
+		if (ops->trampoline == FTRACE_GRAPH_ADDR)
+			return (void *)prepare_ftrace_return;
+#endif
+		return NULL;
+	}
+
+	offset = calc_trampoline_call_offset(save_regs);
+
+	if (save_regs)
+		ptr = (void *)FTRACE_REGS_ADDR + offset;
+	else
+		ptr = (void *)FTRACE_ADDR + offset;
+
+	return addr_from_call(ptr);
+}
+
+void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
+{
+	unsigned long offset;
+
+	/* If we didn't allocate this trampoline, consider it static */
+	if (!ops || !(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
+		return static_tramp_func(ops, rec);
+
+	offset = calc_trampoline_call_offset(ops->flags & FTRACE_OPS_FL_SAVE_REGS);
+	return addr_from_call((void *)ops->trampoline + offset);
+}
+
+void arch_ftrace_trampoline_free(struct ftrace_ops *ops)
+{
+	if (!ops || !(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
+		return;
+
+	tramp_free((void *)ops->trampoline);
+	ops->trampoline = 0;
+}
+
+#endif /* CONFIG_X86_64 */
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+extern void ftrace_graph_call(void);
 
 static int ftrace_mod_jmp(unsigned long ip, void *func)
 {
@@ -694,7 +964,7 @@ int ftrace_disable_ftrace_graph_caller(void)
  * Hook the return address and push it in the stack of return addrs
  * in current thread info.
  */
-void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
+void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
 			   unsigned long frame_pointer)
 {
 	unsigned long old;
diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c
index 717b02a22e6..5f8f0b3cc67 100644
--- a/arch/x86/kernel/kprobes/ftrace.c
+++ b/arch/x86/kernel/kprobes/ftrace.c
@@ -27,7 +27,7 @@
 
 static nokprobe_inline
 int __skip_singlestep(struct kprobe *p, struct pt_regs *regs,
-		      struct kprobe_ctlblk *kcb)
+		      struct kprobe_ctlblk *kcb, unsigned long orig_ip)
 {
 	/*
 	 * Emulate singlestep (and also recover regs->ip)
@@ -39,6 +39,8 @@ int __skip_singlestep(struct kprobe *p, struct pt_regs *regs,
 		p->post_handler(p, regs, 0);
 	}
 	__this_cpu_write(current_kprobe, NULL);
+	if (orig_ip)
+		regs->ip = orig_ip;
 	return 1;
 }
 
@@ -46,7 +48,7 @@ int skip_singlestep(struct kprobe *p, struct pt_regs *regs,
 		    struct kprobe_ctlblk *kcb)
 {
 	if (kprobe_ftrace(p))
-		return __skip_singlestep(p, regs, kcb);
+		return __skip_singlestep(p, regs, kcb, 0);
 	else
 		return 0;
 }
@@ -71,13 +73,14 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
 	if (kprobe_running()) {
 		kprobes_inc_nmissed_count(p);
 	} else {
+		unsigned long orig_ip = regs->ip;
 		/* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */
 		regs->ip = ip + sizeof(kprobe_opcode_t);
 
 		__this_cpu_write(current_kprobe, p);
 		kcb->kprobe_status = KPROBE_HIT_ACTIVE;
 		if (!p->pre_handler || !p->pre_handler(p, regs))
-			__skip_singlestep(p, regs, kcb);
+			__skip_singlestep(p, regs, kcb, orig_ip);
 		/*
 		 * If pre_handler returns !0, it sets regs->ip and
 		 * resets current kprobe.
diff --git a/arch/x86/kernel/mcount_64.S b/arch/x86/kernel/mcount_64.S
index c73aecf10d3..94ea120fa21 100644
--- a/arch/x86/kernel/mcount_64.S
+++ b/arch/x86/kernel/mcount_64.S
@@ -21,40 +21,159 @@
 # define function_hook	mcount
 #endif
 
+/* All cases save the original rbp (8 bytes) */
+#ifdef CONFIG_FRAME_POINTER
+# ifdef CC_USING_FENTRY
+/* Save parent and function stack frames (rip and rbp) */
+#  define MCOUNT_FRAME_SIZE	(8+16*2)
+# else
+/* Save just function stack frame (rip and rbp) */
+#  define MCOUNT_FRAME_SIZE	(8+16)
+# endif
+#else
+/* No need to save a stack frame */
+# define MCOUNT_FRAME_SIZE	8
+#endif /* CONFIG_FRAME_POINTER */
+
+/* Size of stack used to save mcount regs in save_mcount_regs */
+#define MCOUNT_REG_SIZE		(SS+8 + MCOUNT_FRAME_SIZE)
+
+/*
+ * gcc -pg option adds a call to 'mcount' in most functions.
+ * When -mfentry is used, the call is to 'fentry' and not 'mcount'
+ * and is done before the function's stack frame is set up.
+ * They both require a set of regs to be saved before calling
+ * any C code and restored before returning back to the function.
+ *
+ * On boot up, all these calls are converted into nops. When tracing
+ * is enabled, the call can jump to either ftrace_caller or
+ * ftrace_regs_caller. Callbacks (tracing functions) that require
+ * ftrace_regs_caller (like kprobes) need to have pt_regs passed to
+ * it. For this reason, the size of the pt_regs structure will be
+ * allocated on the stack and the required mcount registers will
+ * be saved in the locations that pt_regs has them in.
+ */
+
+/*
+ * @added: the amount of stack added before calling this
+ *
+ * After this is called, the following registers contain:
+ *
+ *  %rdi - holds the address that called the trampoline
+ *  %rsi - holds the parent function (traced function's return address)
+ *  %rdx - holds the original %rbp
+ */
+.macro save_mcount_regs added=0
+
+	/* Always save the original rbp */
+	pushq %rbp
+
+#ifdef CONFIG_FRAME_POINTER
+	/*
+	 * Stack traces will stop at the ftrace trampoline if the frame pointer
+	 * is not set up properly. If fentry is used, we need to save a frame
+	 * pointer for the parent as well as the function traced, because the
+	 * fentry is called before the stack frame is set up, where as mcount
+	 * is called afterward.
+	 */
+#ifdef CC_USING_FENTRY
+	/* Save the parent pointer (skip orig rbp and our return address) */
+	pushq \added+8*2(%rsp)
+	pushq %rbp
+	movq %rsp, %rbp
+	/* Save the return address (now skip orig rbp, rbp and parent) */
+	pushq \added+8*3(%rsp)
+#else
+	/* Can't assume that rip is before this (unless added was zero) */
+	pushq \added+8(%rsp)
+#endif
+	pushq %rbp
+	movq %rsp, %rbp
+#endif /* CONFIG_FRAME_POINTER */
+
+	/*
+	 * We add enough stack to save all regs.
+	 */
+	subq $(MCOUNT_REG_SIZE - MCOUNT_FRAME_SIZE), %rsp
+	movq %rax, RAX(%rsp)
+	movq %rcx, RCX(%rsp)
+	movq %rdx, RDX(%rsp)
+	movq %rsi, RSI(%rsp)
+	movq %rdi, RDI(%rsp)
+	movq %r8, R8(%rsp)
+	movq %r9, R9(%rsp)
+	/*
+	 * Save the original RBP. Even though the mcount ABI does not
+	 * require this, it helps out callers.
+	 */
+	movq MCOUNT_REG_SIZE-8(%rsp), %rdx
+	movq %rdx, RBP(%rsp)
+
+	/* Copy the parent address into %rsi (second parameter) */
+#ifdef CC_USING_FENTRY
+	movq MCOUNT_REG_SIZE+8+\added(%rsp), %rsi
+#else
+	/* %rdx contains original %rbp */
+	movq 8(%rdx), %rsi
+#endif
+
+	 /* Move RIP to its proper location */
+	movq MCOUNT_REG_SIZE+\added(%rsp), %rdi
+	movq %rdi, RIP(%rsp)
+
+	/*
+	 * Now %rdi (the first parameter) has the return address of
+	 * where ftrace_call returns. But the callbacks expect the
+	 * address of the call itself.
+	 */
+	subq $MCOUNT_INSN_SIZE, %rdi
+	.endm
+
+.macro restore_mcount_regs
+	movq R9(%rsp), %r9
+	movq R8(%rsp), %r8
+	movq RDI(%rsp), %rdi
+	movq RSI(%rsp), %rsi
+	movq RDX(%rsp), %rdx
+	movq RCX(%rsp), %rcx
+	movq RAX(%rsp), %rax
+
+	/* ftrace_regs_caller can modify %rbp */
+	movq RBP(%rsp), %rbp
+
+	addq $MCOUNT_REG_SIZE, %rsp
+
+	.endm
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 
 ENTRY(function_hook)
 	retq
 END(function_hook)
 
-/* skip is set if stack has been adjusted */
-.macro ftrace_caller_setup skip=0
-	MCOUNT_SAVE_FRAME \skip
+ENTRY(ftrace_caller)
+	/* save_mcount_regs fills in first two parameters */
+	save_mcount_regs
 
+GLOBAL(ftrace_caller_op_ptr)
 	/* Load the ftrace_ops into the 3rd parameter */
 	movq function_trace_op(%rip), %rdx
 
-	/* Load ip into the first parameter */
-	movq RIP(%rsp), %rdi
-	subq $MCOUNT_INSN_SIZE, %rdi
-	/* Load the parent_ip into the second parameter */
-#ifdef CC_USING_FENTRY
-	movq SS+16(%rsp), %rsi
-#else
-	movq 8(%rbp), %rsi
-#endif
-.endm
-
-ENTRY(ftrace_caller)
-	ftrace_caller_setup
 	/* regs go into 4th parameter (but make it NULL) */
 	movq $0, %rcx
 
 GLOBAL(ftrace_call)
 	call ftrace_stub
 
-	MCOUNT_RESTORE_FRAME
-ftrace_return:
+	restore_mcount_regs
+
+	/*
+	 * The copied trampoline must call ftrace_return as it
+	 * still may need to call the function graph tracer.
+	 */
+GLOBAL(ftrace_caller_end)
+
+GLOBAL(ftrace_return)
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 GLOBAL(ftrace_graph_call)
@@ -66,11 +185,16 @@ GLOBAL(ftrace_stub)
 END(ftrace_caller)
 
 ENTRY(ftrace_regs_caller)
-	/* Save the current flags before compare (in SS location)*/
+	/* Save the current flags before any operations that can change them */
 	pushfq
 
-	/* skip=8 to skip flags saved in SS */
-	ftrace_caller_setup 8
+	/* added 8 bytes to save flags */
+	save_mcount_regs 8
+	/* save_mcount_regs fills in first two parameters */
+
+GLOBAL(ftrace_regs_caller_op_ptr)
+	/* Load the ftrace_ops into the 3rd parameter */
+	movq function_trace_op(%rip), %rdx
 
 	/* Save the rest of pt_regs */
 	movq %r15, R15(%rsp)
@@ -79,18 +203,17 @@ ENTRY(ftrace_regs_caller)
 	movq %r12, R12(%rsp)
 	movq %r11, R11(%rsp)
 	movq %r10, R10(%rsp)
-	movq %rbp, RBP(%rsp)
 	movq %rbx, RBX(%rsp)
 	/* Copy saved flags */
-	movq SS(%rsp), %rcx
+	movq MCOUNT_REG_SIZE(%rsp), %rcx
 	movq %rcx, EFLAGS(%rsp)
 	/* Kernel segments */
 	movq $__KERNEL_DS, %rcx
 	movq %rcx, SS(%rsp)
 	movq $__KERNEL_CS, %rcx
 	movq %rcx, CS(%rsp)
-	/* Stack - skipping return address */
-	leaq SS+16(%rsp), %rcx
+	/* Stack - skipping return address and flags */
+	leaq MCOUNT_REG_SIZE+8*2(%rsp), %rcx
 	movq %rcx, RSP(%rsp)
 
 	/* regs go into 4th parameter */
@@ -101,11 +224,11 @@ GLOBAL(ftrace_regs_call)
 
 	/* Copy flags back to SS, to restore them */
 	movq EFLAGS(%rsp), %rax
-	movq %rax, SS(%rsp)
+	movq %rax, MCOUNT_REG_SIZE(%rsp)
 
 	/* Handlers can change the RIP */
 	movq RIP(%rsp), %rax
-	movq %rax, SS+8(%rsp)
+	movq %rax, MCOUNT_REG_SIZE+8(%rsp)
 
 	/* restore the rest of pt_regs */
 	movq R15(%rsp), %r15
@@ -113,19 +236,22 @@ GLOBAL(ftrace_regs_call)
 	movq R13(%rsp), %r13
 	movq R12(%rsp), %r12
 	movq R10(%rsp), %r10
-	movq RBP(%rsp), %rbp
 	movq RBX(%rsp), %rbx
 
-	/* skip=8 to skip flags saved in SS */
-	MCOUNT_RESTORE_FRAME 8
+	restore_mcount_regs
 
 	/* Restore flags */
 	popfq
 
-	jmp ftrace_return
+	/*
+	 * As this jmp to ftrace_return can be a short jump
+	 * it must not be copied into the trampoline.
+	 * The trampoline will add the code to jump
+	 * to the return.
+	 */
+GLOBAL(ftrace_regs_caller_end)
 
-	popfq
-	jmp  ftrace_stub
+	jmp ftrace_return
 
 END(ftrace_regs_caller)
 
@@ -136,6 +262,7 @@ ENTRY(function_hook)
 	cmpq $ftrace_stub, ftrace_trace_function
 	jnz trace
 
+fgraph_trace:
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	cmpq $ftrace_stub, ftrace_graph_return
 	jnz ftrace_graph_caller
@@ -148,42 +275,35 @@ GLOBAL(ftrace_stub)
 	retq
 
 trace:
-	MCOUNT_SAVE_FRAME
-
-	movq RIP(%rsp), %rdi
-#ifdef CC_USING_FENTRY
-	movq SS+16(%rsp), %rsi
-#else
-	movq 8(%rbp), %rsi
-#endif
-	subq $MCOUNT_INSN_SIZE, %rdi
+	/* save_mcount_regs fills in first two parameters */
+	save_mcount_regs
 
 	call   *ftrace_trace_function
 
-	MCOUNT_RESTORE_FRAME
+	restore_mcount_regs
 
-	jmp ftrace_stub
+	jmp fgraph_trace
 END(function_hook)
 #endif /* CONFIG_DYNAMIC_FTRACE */
 #endif /* CONFIG_FUNCTION_TRACER */
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 ENTRY(ftrace_graph_caller)
-	MCOUNT_SAVE_FRAME
+	/* Saves rbp into %rdx and fills first parameter  */
+	save_mcount_regs
 
 #ifdef CC_USING_FENTRY
-	leaq SS+16(%rsp), %rdi
+	leaq MCOUNT_REG_SIZE+8(%rsp), %rsi
 	movq $0, %rdx	/* No framepointers needed */
 #else
-	leaq 8(%rbp), %rdi
-	movq (%rbp), %rdx
+	/* Save address of the return address of traced function */
+	leaq 8(%rdx), %rsi
+	/* ftrace does sanity checks against frame pointers */
+	movq (%rdx), %rdx
 #endif
-	movq RIP(%rsp), %rsi
-	subq $MCOUNT_INSN_SIZE, %rsi
-
 	call	prepare_ftrace_return
 
-	MCOUNT_RESTORE_FRAME
+	restore_mcount_regs
 
 	retq
 END(ftrace_graph_caller)
diff --git a/arch/x86/kvm/mmutrace.h b/arch/x86/kvm/mmutrace.h
index 5aaf3564176..ce463a9cc8f 100644
--- a/arch/x86/kvm/mmutrace.h
+++ b/arch/x86/kvm/mmutrace.h
@@ -22,7 +22,7 @@
 	__entry->unsync = sp->unsync;
 
 #define KVM_MMU_PAGE_PRINTK() ({				        \
-	const u32 saved_len = p->len;					\
+	const char *saved_ptr = trace_seq_buffer_ptr(p);		\
 	static const char *access_str[] = {			        \
 		"---", "--x", "w--", "w-x", "-u-", "-ux", "wu-", "wux"  \
 	};							        \
@@ -41,7 +41,7 @@
 			 role.nxe ? "" : "!",				\
 			 __entry->root_count,				\
 			 __entry->unsync ? "unsync" : "sync", 0);	\
-	p->buffer + saved_len;						\
+	saved_ptr;							\
 		})
 
 #define kvm_mmu_trace_pferr_flags       \