Merge tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Restructure of lockdep and latency tracers

   This is the biggest change. Joel Fernandes restructured the hooks
   from irqs and preemption disabling and enabling. He got rid of a lot
   of the preprocessor #ifdef mess that they caused.

   He turned both lockdep and the latency tracers to use trace events
   inserted in the preempt/irqs disabling paths. But unfortunately,
   these started to cause issues in corner cases. Thus, parts of the
   code was reverted back to where lockdep and the latency tracers just
   get called directly (without using the trace events). But because the
   original change cleaned up the code very nicely we kept that, as well
   as the trace events for preempt and irqs disabling, but they are
   limited to not being called in NMIs.

 - Have trace events use SRCU for "rcu idle" calls. This was required
   for the preempt/irqs off trace events. But it also had to not allow
   them to be called in NMI context. Waiting till Paul makes an NMI safe
   SRCU API.

 - New notrace SRCU API to allow trace events to use SRCU.

 - Addition of mcount-nop option support

 - SPDX headers replacing GPL templates.

 - Various other fixes and clean ups.

 - Some fixes are marked for stable, but were not fully tested before
   the merge window opened.

* tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits)
  tracing: Fix SPDX format headers to use C++ style comments
  tracing: Add SPDX License format tags to tracing files
  tracing: Add SPDX License format to bpf_trace.c
  blktrace: Add SPDX License format header
  s390/ftrace: Add -mfentry and -mnop-mcount support
  tracing: Add -mcount-nop option support
  tracing: Avoid calling cc-option -mrecord-mcount for every Makefile
  tracing: Handle CC_FLAGS_FTRACE more accurately
  Uprobe: Additional argument arch_uprobe to uprobe_write_opcode()
  Uprobes: Simplify uprobe_register() body
  tracepoints: Free early tracepoints after RCU is initialized
  uprobes: Use synchronize_rcu() not synchronize_sched()
  tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister()
  ftrace: Remove unused pointer ftrace_swapper_pid
  tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage"
  tracing/irqsoff: Handle preempt_count for different configs
  tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage"
  tracing: irqsoff: Account for additional preempt_disable
  trace: Use rcu_dereference_raw for hooks from trace-event subsystem
  tracing/kprobes: Fix within_notrace_func() to check only notrace functions
  ...

5 files changed, 16 insertions, 12 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index a6afa60074cb..054b29c9a533 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -135,6 +135,7 @@ config S390
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
+	select HAVE_FENTRY
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_TRACER
@@ -157,6 +158,7 @@ config S390
 	select HAVE_MEMBLOCK_NODE_MAP
 	select HAVE_MEMBLOCK_PHYS_MAP
 	select HAVE_MOD_ARCH_SPECIFIC
+	select HAVE_NOP_MCOUNT
 	select HAVE_OPROFILE
 	select HAVE_PERF_EVENTS
 	select HAVE_REGS_AND_STACK_ACCESS_API
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index eee6703093c3..ba6d122526fb 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -96,13 +96,15 @@ ifdef CONFIG_EXPOLINE
 endif
 
 ifdef CONFIG_FUNCTION_TRACER
-# make use of hotpatch feature if the compiler supports it
-cc_hotpatch	:= -mhotpatch=0,3
-ifeq ($(call cc-option-yn,$(cc_hotpatch)),y)
-CC_FLAGS_FTRACE := $(cc_hotpatch)
-KBUILD_AFLAGS	+= -DCC_USING_HOTPATCH
-KBUILD_CFLAGS	+= -DCC_USING_HOTPATCH
-endif
+  ifeq ($(call cc-option-yn,-mfentry -mnop-mcount),n)
+    # make use of hotpatch feature if the compiler supports it
+    cc_hotpatch	:= -mhotpatch=0,3
+    ifeq ($(call cc-option-yn,$(cc_hotpatch)),y)
+      CC_FLAGS_FTRACE := $(cc_hotpatch)
+      KBUILD_AFLAGS	+= -DCC_USING_HOTPATCH
+      KBUILD_CFLAGS	+= -DCC_USING_HOTPATCH
+    endif
+  endif
 endif
 
 # Test CFI features of binutils
diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h
index cfccc0edd00d..8ea270fdc7fb 100644
--- a/arch/s390/include/asm/ftrace.h
+++ b/arch/s390/include/asm/ftrace.h
@@ -4,7 +4,7 @@
 
 #define ARCH_SUPPORTS_FTRACE_OPS 1
 
-#ifdef CC_USING_HOTPATCH
+#if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)
 #define MCOUNT_INSN_SIZE	6
 #else
 #define MCOUNT_INSN_SIZE	24
@@ -42,7 +42,7 @@ struct ftrace_insn {
 static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn)
 {
 #ifdef CONFIG_FUNCTION_TRACER
-#ifdef CC_USING_HOTPATCH
+#if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)
 	/* brcl 0,0 */
 	insn->opc = 0xc004;
 	insn->disp = 0;
@@ -57,7 +57,7 @@ static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn)
 static inline int is_ftrace_nop(struct ftrace_insn *insn)
 {
 #ifdef CONFIG_FUNCTION_TRACER
-#ifdef CC_USING_HOTPATCH
+#if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)
 	if (insn->disp == 0)
 		return 1;
 #else
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index dc76d813e420..84be7f02d0c2 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -61,7 +61,7 @@ unsigned long ftrace_plt;
 
 static inline void ftrace_generate_orig_insn(struct ftrace_insn *insn)
 {
-#ifdef CC_USING_HOTPATCH
+#if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)
 	/* brcl 0,0 */
 	insn->opc = 0xc004;
 	insn->disp = 0;
diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S
index 27110f3294ed..e93fbf02490c 100644
--- a/arch/s390/kernel/mcount.S
+++ b/arch/s390/kernel/mcount.S
@@ -35,7 +35,7 @@ ENTRY(ftrace_caller)
 	.globl	ftrace_regs_caller
 	.set	ftrace_regs_caller,ftrace_caller
 	lgr	%r1,%r15
-#ifndef CC_USING_HOTPATCH
+#if !(defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT))
 	aghi	%r0,MCOUNT_RETURN_FIXUP
 #endif
 	aghi	%r15,-STACK_FRAME_SIZE