Merge tag 'trace-3.17' of git://git.kernel.org/pub/scm/linux/kernel/g…

…it/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "This pull request has a lot of work done.  The main thing is the
  changes to the ftrace function callback infrastructure.  It's
  introducing a way to allow different functions to call directly
  different trampolines instead of all calling the same "mcount" one.

  The only user of this for now is the function graph tracer, which
  always had a different trampoline, but the function tracer trampoline
  was called and did basically nothing, and then the function graph
  tracer trampoline was called.  The difference now, is that the
  function graph tracer trampoline can be called directly if a function
  is only being traced by the function graph trampoline.  If function
  tracing is also happening on the same function, the old way is still
  done.

  The accounting for this takes up more memory when function graph
  tracing is activated, as it needs to keep track of which functions it
  uses.  I have a new way that wont take as much memory, but it's not
  ready yet for this merge window, and will have to wait for the next
  one.

  Another big change was the removal of the ftrace_start/stop() calls
  that were used by the suspend/resume code that stopped function
  tracing when entering into suspend and resume paths.  The stop of
  ftrace was done because there was some function that would crash the
  system if one called smp_processor_id()! The stop/start was a big
  hammer to solve the issue at the time, which was when ftrace was first
  introduced into Linux.  Now ftrace has better infrastructure to debug
  such issues, and I found the problem function and labeled it with
  "notrace" and function tracing can now safely be activated all the way
  down into the guts of suspend and resume

  Other changes include clean ups of uprobe code, clean up of the
  trace_seq() code, and other various small fixes and clean ups to
  ftrace and tracing"

* tag 'trace-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (57 commits)
  ftrace: Add warning if tramp hash does not match nr_trampolines
  ftrace: Fix trampoline hash update check on rec->flags
  ring-buffer: Use rb_page_size() instead of open coded head_page size
  ftrace: Rename ftrace_ops field from trampolines to nr_trampolines
  tracing: Convert local function_graph functions to static
  ftrace: Do not copy old hash when resetting
  tracing: let user specify tracing_thresh after selecting function_graph
  ring-buffer: Always run per-cpu ring buffer resize with schedule_work_on()
  tracing: Remove function_trace_stop and HAVE_FUNCTION_TRACE_MCOUNT_TEST
  s390/ftrace: remove check of obsolete variable function_trace_stop
  arm64, ftrace: Remove check of obsolete variable function_trace_stop
  Blackfin: ftrace: Remove check of obsolete variable function_trace_stop
  metag: ftrace: Remove check of obsolete variable function_trace_stop
  microblaze: ftrace: Remove check of obsolete variable function_trace_stop
  MIPS: ftrace: Remove check of obsolete variable function_trace_stop
  parisc: ftrace: Remove check of obsolete variable function_trace_stop
  sh: ftrace: Remove check of obsolete variable function_trace_stop
  sparc64,ftrace: Remove check of obsolete variable function_trace_stop
  tile: ftrace: Remove check of obsolete variable function_trace_stop
  ftrace: x86: Remove check of obsolete variable function_trace_stop
  ...

Documentation/kernel-parameters.txt

@@ -1097,6 +1097,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			that can be changed at run time by the
 			set_graph_function file in the debugfs tracing directory.
 
+	ftrace_graph_notrace=[function-list]
+			[FTRACE] Do not trace from the functions specified in
+			function-list.  This list is a comma separated list of
+			functions that can be changed at run time by the
+			set_graph_notrace file in the debugfs tracing directory.
+
 	gamecon.map[2|3]=
 			[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
 			support via parallel port (up to 5 devices per port)

Documentation/trace/ftrace-design.txt

@@ -102,30 +102,6 @@ extern void mcount(void);
 EXPORT_SYMBOL(mcount);
 
 
-HAVE_FUNCTION_TRACE_MCOUNT_TEST
--------------------------------
-
-This is an optional optimization for the normal case when tracing is turned off
-in the system.  If you do not enable this Kconfig option, the common ftrace
-code will take care of doing the checking for you.
-
-To support this feature, you only need to check the function_trace_stop
-variable in the mcount function.  If it is non-zero, there is no tracing to be
-done at all, so you can return.
-
-This additional pseudo code would simply be:
-void mcount(void)
-{
-	/* save any bare state needed in order to do initial checking */
-
-+	if (function_trace_stop)
-+		return;
-
-	extern void (*ftrace_trace_function)(unsigned long, unsigned long);
-	if (ftrace_trace_function != ftrace_stub)
-...
-
-
 HAVE_FUNCTION_GRAPH_TRACER
 --------------------------
 
@@ -328,8 +304,6 @@ void mcount(void)
 
 void ftrace_caller(void)
 {
-	/* implement HAVE_FUNCTION_TRACE_MCOUNT_TEST if you desire */
-
 	/* save all state needed by the ABI (see paragraph above) */
 
 	unsigned long frompc = ...;

arch/arm64/kernel/entry-ftrace.S

@@ -96,11 +96,6 @@
  *     - ftrace_graph_caller to set up an exit hook
  */
 ENTRY(_mcount)
-#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
-	ldr	x0, =ftrace_trace_stop
-	ldr	x0, [x0]		// if ftrace_trace_stop
-	ret				//   return;
-#endif
 	mcount_enter
 
 	ldr	x0, =ftrace_trace_function

arch/blackfin/Kconfig

@@ -18,7 +18,6 @@ config BLACKFIN
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_TRACER
-	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	select HAVE_IDE
 	select HAVE_KERNEL_GZIP if RAMKERNEL
 	select HAVE_KERNEL_BZIP2 if RAMKERNEL

arch/blackfin/kernel/ftrace-entry.S

@@ -33,15 +33,6 @@ ENDPROC(__mcount)
  * function will be waiting there.  mmmm pie.
  */
 ENTRY(_ftrace_caller)
-# ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
-	/* optional micro optimization: return if stopped */
-	p1.l = _function_trace_stop;
-	p1.h = _function_trace_stop;
-	r3 = [p1];
-	cc = r3 == 0;
-	if ! cc jump _ftrace_stub (bp);
-# endif
-
 	/* save first/second/third function arg and the return register */
 	[--sp] = r2;
 	[--sp] = r0;
@@ -83,15 +74,6 @@ ENDPROC(_ftrace_caller)
 
 /* See documentation for _ftrace_caller */
 ENTRY(__mcount)
-# ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
-	/* optional micro optimization: return if stopped */
-	p1.l = _function_trace_stop;
-	p1.h = _function_trace_stop;
-	r3 = [p1];
-	cc = r3 == 0;
-	if ! cc jump _ftrace_stub (bp);
-# endif
-
 	/* save third function arg early so we can do testing below */
 	[--sp] = r2;
 

arch/metag/Kconfig

@@ -13,7 +13,6 @@ config METAG
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_TRACER
-	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	select HAVE_KERNEL_BZIP2
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZO

arch/metag/kernel/ftrace_stub.S

@@ -16,13 +16,6 @@ _mcount_wrapper:
 	.global _ftrace_caller
 	.type	_ftrace_caller,function
 _ftrace_caller:
-	MOVT    D0Re0,#HI(_function_trace_stop)
-	ADD	D0Re0,D0Re0,#LO(_function_trace_stop)
-	GETD	D0Re0,[D0Re0]
-	CMP	D0Re0,#0
-	BEQ	$Lcall_stub
-	MOV	PC,D0.4
-$Lcall_stub:
 	MSETL   [A0StP], D0Ar6, D0Ar4, D0Ar2, D0.4
 	MOV     D1Ar1, D0.4
 	MOV     D0Ar2, D1RtP
@@ -42,13 +35,6 @@ _ftrace_call:
 	.global	_mcount_wrapper
 	.type	_mcount_wrapper,function
 _mcount_wrapper:
-	MOVT    D0Re0,#HI(_function_trace_stop)
-	ADD	D0Re0,D0Re0,#LO(_function_trace_stop)
-	GETD	D0Re0,[D0Re0]
-	CMP	D0Re0,#0
-	BEQ	$Lcall_mcount
-	MOV	PC,D0.4
-$Lcall_mcount:
 	MSETL   [A0StP], D0Ar6, D0Ar4, D0Ar2, D0.4
 	MOV     D1Ar1, D0.4
 	MOV     D0Ar2, D1RtP

arch/microblaze/Kconfig

@@ -22,7 +22,6 @@ config MICROBLAZE
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_GRAPH_TRACER
-	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	select HAVE_FUNCTION_TRACER
 	select HAVE_MEMBLOCK
 	select HAVE_MEMBLOCK_NODE_MAP

arch/microblaze/kernel/ftrace.c

@@ -27,6 +27,9 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 	unsigned long return_hooker = (unsigned long)
 				&return_to_handler;
 
+	if (unlikely(ftrace_graph_is_dead()))
+		return;
+
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
 		return;
 

arch/microblaze/kernel/mcount.S

@@ -91,11 +91,6 @@ ENTRY(ftrace_caller)
 #endif /* CONFIG_DYNAMIC_FTRACE */
 	SAVE_REGS
 	swi	r15, r1, 0;
-	/* MS: HAVE_FUNCTION_TRACE_MCOUNT_TEST begin of checking */
-	lwi	r5, r0, function_trace_stop;
-	bneid	r5, end;
-	nop;
-	/* MS: HAVE_FUNCTION_TRACE_MCOUNT_TEST end of checking */
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 #ifndef CONFIG_DYNAMIC_FTRACE
 	lwi	r5, r0, ftrace_graph_return;

arch/mips/Kconfig

@@ -15,7 +15,6 @@ config MIPS
 	select HAVE_BPF_JIT if !CPU_MICROMIPS
 	select ARCH_HAVE_CUSTOM_GPIO_H
 	select HAVE_FUNCTION_TRACER
-	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_C_RECORDMCOUNT

arch/mips/kernel/ftrace.c

@@ -302,6 +302,9 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra,
 	    &return_to_handler;
 	int faulted, insns;
 
+	if (unlikely(ftrace_graph_is_dead()))
+		return;
+
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
 		return;
 

arch/mips/kernel/mcount.S

@@ -74,10 +74,6 @@ _mcount:
 #endif
 
 	/* When tracing is activated, it calls ftrace_caller+8 (aka here) */
-	lw	t1, function_trace_stop
-	bnez	t1, ftrace_stub
-	 nop
-
 	MCOUNT_SAVE_REGS
 #ifdef KBUILD_MCOUNT_RA_ADDRESS
 	PTR_S	MCOUNT_RA_ADDRESS_REG, PT_R12(sp)
@@ -105,9 +101,6 @@ ftrace_stub:
 #else	/* ! CONFIG_DYNAMIC_FTRACE */
 
 NESTED(_mcount, PT_SIZE, ra)
-	lw	t1, function_trace_stop
-	bnez	t1, ftrace_stub
-	 nop
 	PTR_LA	t1, ftrace_stub
 	PTR_L	t2, ftrace_trace_function /* Prepare t2 for (1) */
 	bne	t1, t2, static_trace

arch/parisc/Kconfig

@@ -6,7 +6,6 @@ config PARISC
 	select HAVE_OPROFILE
 	select HAVE_FUNCTION_TRACER if 64BIT
 	select HAVE_FUNCTION_GRAPH_TRACER if 64BIT
-	select HAVE_FUNCTION_TRACE_MCOUNT_TEST if 64BIT
 	select ARCH_WANT_FRAME_POINTERS
 	select RTC_CLASS
 	select RTC_DRV_GENERIC

arch/parisc/kernel/ftrace.c

@@ -112,6 +112,9 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 	unsigned long long calltime;
 	struct ftrace_graph_ent trace;
 
+	if (unlikely(ftrace_graph_is_dead()))
+		return;
+
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
 		return;
 
@@ -152,9 +155,6 @@ void ftrace_function_trampoline(unsigned long parent,
 {
 	extern ftrace_func_t ftrace_trace_function;
 
-	if (function_trace_stop)
-		return;
-
 	if (ftrace_trace_function != ftrace_stub) {
 		ftrace_trace_function(parent, self_addr);
 		return;

arch/powerpc/kernel/ftrace.c

@@ -525,6 +525,9 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 	struct ftrace_graph_ent trace;
 	unsigned long return_hooker = (unsigned long)&return_to_handler;
 
+	if (unlikely(ftrace_graph_is_dead()))
+		return;
+
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
 		return;
 

arch/s390/Kconfig

@@ -116,7 +116,6 @@ config S390
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_TRACER
-	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_KERNEL_BZIP2
 	select HAVE_KERNEL_GZIP

arch/s390/kernel/mcount.S

@@ -21,13 +21,9 @@ ENTRY(_mcount)
 ENTRY(ftrace_caller)
 #endif
 	stm	%r2,%r5,16(%r15)
-	bras	%r1,2f
+	bras	%r1,1f
 0:	.long	ftrace_trace_function
-1:	.long	function_trace_stop
-2:	l	%r2,1b-0b(%r1)
-	icm	%r2,0xf,0(%r2)
-	jnz	3f
-	st	%r14,56(%r15)
+1:	st	%r14,56(%r15)
 	lr	%r0,%r15
 	ahi	%r15,-96
 	l	%r3,100(%r15)
@@ -50,7 +46,7 @@ ENTRY(ftrace_graph_caller)
 #endif
 	ahi	%r15,96
 	l	%r14,56(%r15)
-3:	lm	%r2,%r5,16(%r15)
+	lm	%r2,%r5,16(%r15)
 	br	%r14
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER

arch/s390/kernel/mcount64.S

@@ -20,9 +20,6 @@ ENTRY(_mcount)
 
 ENTRY(ftrace_caller)
 #endif
-	larl	%r1,function_trace_stop
-	icm	%r1,0xf,0(%r1)
-	bnzr	%r14
 	stmg	%r2,%r5,32(%r15)
 	stg	%r14,112(%r15)
 	lgr	%r1,%r15

arch/sh/Kconfig

@@ -57,7 +57,6 @@ config SUPERH32
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_DYNAMIC_FTRACE
-	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select HAVE_FUNCTION_GRAPH_TRACER

arch/sh/kernel/ftrace.c

@@ -344,6 +344,9 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 	struct ftrace_graph_ent trace;
 	unsigned long return_hooker = (unsigned long)&return_to_handler;
 
+	if (unlikely(ftrace_graph_is_dead()))
+		return;
+
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
 		return;
 

arch/sh/lib/mcount.S

@@ -92,13 +92,6 @@ mcount:
 	rts
 	 nop
 #else
-#ifndef CONFIG_DYNAMIC_FTRACE
-	mov.l	.Lfunction_trace_stop, r0
-	mov.l	@r0, r0
-	tst	r0, r0
-	bf	ftrace_stub
-#endif
-
 	MCOUNT_ENTER()
 
 #ifdef CONFIG_DYNAMIC_FTRACE
@@ -174,11 +167,6 @@ ftrace_graph_call:
 
 	.globl ftrace_caller
 ftrace_caller:
-	mov.l	.Lfunction_trace_stop, r0
-	mov.l	@r0, r0
-	tst	r0, r0
-	bf	ftrace_stub
-
 	MCOUNT_ENTER()
 
 	.globl ftrace_call
@@ -196,8 +184,6 @@ ftrace_call:
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 	.align 2
-.Lfunction_trace_stop:
-	.long	function_trace_stop
 
 /*
  * NOTE: From here on the locations of the .Lftrace_stub label and
@@ -217,12 +203,7 @@ ftrace_stub:
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	.globl	ftrace_graph_caller
 ftrace_graph_caller:
-	mov.l	2f, r0
-	mov.l	@r0, r0
-	tst	r0, r0
-	bt	1f
-
-	mov.l	3f, r1
+	mov.l	2f, r1
 	jmp	@r1
 	 nop
 1:
@@ -242,8 +223,7 @@ ftrace_graph_caller:
 	MCOUNT_LEAVE()
 
 	.align 2
-2:	.long	function_trace_stop
-3:	.long	skip_trace
+2:	.long	skip_trace
 .Lprepare_ftrace_return:
 	.long	prepare_ftrace_return
 

arch/sparc/Kconfig

@@ -55,7 +55,6 @@ config SPARC64
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_GRAPH_FP_TEST
-	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	select HAVE_KRETPROBES
 	select HAVE_KPROBES
 	select HAVE_RCU_TABLE_FREE if SMP