Merge tag 'trace-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The majority of the changes are for fixes and clean ups.

  Notable changes:

   - Rework trace event triggers code to be easier to interact with.

   - Support for embedding bootconfig with the kernel (as suppose to
     having it embedded in initram). This is useful for embedded boards
     without initram disks.

   - Speed up boot by parallelizing the creation of tracefs files.

   - Allow absolute ring buffer timestamps handle timestamps that use
     more than 59 bits.

   - Added new tracing clock "TAI" (International Atomic Time)

   - Have weak functions show up in available_filter_function list as:
     __ftrace_invalid_address___<invalid-offset> instead of using the
     name of the function before it"

* tag 'trace-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (52 commits)
  ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid adding weak function
  tracing: Fix comments for event_trigger_separate_filter()
  x86/traceponit: Fix comment about irq vector tracepoints
  x86,tracing: Remove unused headers
  ftrace: Clean up hash direct_functions on register failures
  tracing: Fix comments of create_filter()
  tracing: Disable kcov on trace_preemptirq.c
  tracing: Initialize integer variable to prevent garbage return value
  ftrace: Fix typo in comment
  ftrace: Remove return value of ftrace_arch_modify_*()
  tracing: Cleanup code by removing init "char *name"
  tracing: Change "char *" string form to "char []"
  tracing/timerlat: Do not wakeup the thread if the trace stops at the IRQ
  tracing/timerlat: Print stacktrace in the IRQ handler if needed
  tracing/timerlat: Notify IRQ new max latency only if stop tracing is set
  kprobes: Fix build errors with CONFIG_KRETPROBES=n
  tracing: Fix return value of trace_pid_write()
  tracing: Fix potential double free in create_var_ref()
  tracing: Use strim() to remove whitespace instead of doing it manually
  ftrace: Deal with error return code of the ftrace_process_locs() function
  ...

Author: torvalds

Documentation/admin-guide/bootconfig.rst

@@ -158,9 +158,15 @@ Each key-value pair is shown in each line with following style::
 Boot Kernel With a Boot Config
 ==============================
 
-Since the boot configuration file is loaded with initrd, it will be added
-to the end of the initrd (initramfs) image file with padding, size,
-checksum and 12-byte magic word as below.
+There are two options to boot the kernel with bootconfig: attaching the
+bootconfig to the initrd image or embedding it in the kernel itself.
+
+Attaching a Boot Config to Initrd
+---------------------------------
+
+Since the boot configuration file is loaded with initrd by default,
+it will be added to the end of the initrd (initramfs) image file with
+padding, size, checksum and 12-byte magic word as below.
 
 [initrd][bootconfig][padding][size(le32)][checksum(le32)][#BOOTCONFIG\n]
 
@@ -196,6 +202,25 @@ To remove the config from the image, you can use -d option as below::
 Then add "bootconfig" on the normal kernel command line to tell the
 kernel to look for the bootconfig at the end of the initrd file.
 
+Embedding a Boot Config into Kernel
+-----------------------------------
+
+If you can not use initrd, you can also embed the bootconfig file in the
+kernel by Kconfig options. In this case, you need to recompile the kernel
+with the following configs::
+
+ CONFIG_BOOT_CONFIG_EMBED=y
+ CONFIG_BOOT_CONFIG_EMBED_FILE="/PATH/TO/BOOTCONFIG/FILE"
+
+``CONFIG_BOOT_CONFIG_EMBED_FILE`` requires an absolute path or a relative
+path to the bootconfig file from source tree or object tree.
+The kernel will embed it as the default bootconfig.
+
+Just as when attaching the bootconfig to the initrd, you need ``bootconfig``
+option on the kernel command line to enable the embedded bootconfig.
+
+Note that even if you set this option, you can override the embedded
+bootconfig by another bootconfig which attached to the initrd.
 
 Kernel parameters via Boot Config
 =================================

Documentation/trace/ftrace.rst

@@ -517,6 +517,18 @@ of ftrace. Here is a list of some of the key files:
 		processing should be able to handle them. See comments in the
 		ktime_get_boot_fast_ns() function for more information.
 
+	tai:
+		This is the tai clock (CLOCK_TAI) and is derived from the wall-
+		clock time. However, this clock does not experience
+		discontinuities and backwards jumps caused by NTP inserting leap
+		seconds. Since the clock access is designed for use in tracing,
+		side effects are possible. The clock access may yield wrong
+		readouts in case the internal TAI offset is updated e.g., caused
+		by setting the system time or using adjtimex() with an offset.
+		These effects are rare and post processing should be able to
+		handle them. See comments in the ktime_get_tai_fast_ns()
+		function for more information.
+
 	To set a clock, simply echo the clock name into this file::
 
 	  # echo global > trace_clock

Documentation/trace/timerlat-tracer.rst

@@ -74,8 +74,9 @@ directory. The timerlat configs are:
  - stop_tracing_total_us: stop the system tracing if a
    timer latency at the *thread* context is higher than the configured
    value happens. Writing 0 disables this option.
- - print_stack: save the stack of the IRQ occurrence, and print
-   it after the *thread context* event".
+ - print_stack: save the stack of the IRQ occurrence. The stack is printed
+   after the *thread context* event, or at the IRQ handler if *stop_tracing_us*
+   is hit.
 
 timerlat and osnoise
 ----------------------------

MAINTAINERS

@@ -7517,6 +7517,7 @@ S:	Maintained
 F:	Documentation/admin-guide/bootconfig.rst
 F:	fs/proc/bootconfig.c
 F:	include/linux/bootconfig.h
+F:	lib/bootconfig-data.S
 F:	lib/bootconfig.c
 F:	tools/bootconfig/*
 F:	tools/bootconfig/scripts/*
@@ -20119,8 +20120,8 @@ M:	Ingo Molnar <mingo@redhat.com>
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
 F:	Documentation/trace/ftrace.rst
-F:	arch/*/*/*/ftrace.h
-F:	arch/*/kernel/ftrace.c
+F:	arch/*/*/*/*ftrace*
+F:	arch/*/*/*ftrace*
 F:	fs/tracefs/
 F:	include/*/ftrace.h
 F:	include/linux/trace*.h

arch/arm/kernel/ftrace.c

@@ -79,16 +79,14 @@ static unsigned long __ref adjust_address(struct dyn_ftrace *rec,
 	return (unsigned long)&ftrace_regs_caller_from_init;
 }
 
-int ftrace_arch_code_modify_prepare(void)
+void ftrace_arch_code_modify_prepare(void)
 {
-	return 0;
 }
 
-int ftrace_arch_code_modify_post_process(void)
+void ftrace_arch_code_modify_post_process(void)
 {
 	/* Make sure any TLB misses during machine stop are cleared. */
 	flush_tlb_all();
-	return 0;
 }
 
 static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr,

arch/riscv/kernel/ftrace.c

@@ -12,16 +12,14 @@
 #include <asm/patch.h>
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-int ftrace_arch_code_modify_prepare(void) __acquires(&text_mutex)
+void ftrace_arch_code_modify_prepare(void) __acquires(&text_mutex)
 {
 	mutex_lock(&text_mutex);
-	return 0;
 }
 
-int ftrace_arch_code_modify_post_process(void) __releases(&text_mutex)
+void ftrace_arch_code_modify_post_process(void) __releases(&text_mutex)
 {
 	mutex_unlock(&text_mutex);
-	return 0;
 }
 
 static int ftrace_check_current_call(unsigned long hook_pos,

arch/s390/kernel/ftrace.c

@@ -225,14 +225,13 @@ void arch_ftrace_update_code(int command)
 	ftrace_modify_all_code(command);
 }
 
-int ftrace_arch_code_modify_post_process(void)
+void ftrace_arch_code_modify_post_process(void)
 {
 	/*
 	 * Flush any pre-fetched instructions on all
 	 * CPUs to make the new code visible.
 	 */
 	text_poke_sync_lock();
-	return 0;
 }
 
 #ifdef CONFIG_MODULES

arch/x86/include/asm/ftrace.h

@@ -9,6 +9,13 @@
 # define MCOUNT_ADDR		((unsigned long)(__fentry__))
 #define MCOUNT_INSN_SIZE	5 /* sizeof mcount call */
 
+/* Ignore unused weak functions which will have non zero offsets */
+#ifdef CONFIG_HAVE_FENTRY
+# include <asm/ibt.h>
+/* Add offset for endbr64 if IBT enabled */
+# define FTRACE_MCOUNT_MAX_OFFSET	ENDBR_INSN_SIZE
+#endif
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 #define ARCH_SUPPORTS_FTRACE_OPS 1
 #endif

arch/x86/kernel/ftrace.c

@@ -37,7 +37,7 @@
 
 static int ftrace_poke_late = 0;
 
-int ftrace_arch_code_modify_prepare(void)
+void ftrace_arch_code_modify_prepare(void)
     __acquires(&text_mutex)
 {
 	/*
@@ -47,10 +47,9 @@ int ftrace_arch_code_modify_prepare(void)
 	 */
 	mutex_lock(&text_mutex);
 	ftrace_poke_late = 1;
-	return 0;
 }
 
-int ftrace_arch_code_modify_post_process(void)
+void ftrace_arch_code_modify_post_process(void)
     __releases(&text_mutex)
 {
 	/*
@@ -61,7 +60,6 @@ int ftrace_arch_code_modify_post_process(void)
 	text_poke_finish();
 	ftrace_poke_late = 0;
 	mutex_unlock(&text_mutex);
-	return 0;
 }
 
 static const char *ftrace_nop_replace(void)

arch/x86/kernel/tracepoint.c

@@ -1,17 +1,11 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Code for supporting irq vector tracepoints.
- *
  * Copyright (C) 2013 Seiji Aguchi <seiji.aguchi@hds.com>
- *
  */
 #include <linux/jump_label.h>
 #include <linux/atomic.h>
 
-#include <asm/hw_irq.h>
-#include <asm/desc.h>
 #include <asm/trace/exceptions.h>
-#include <asm/trace/irq_vectors.h>
 
 DEFINE_STATIC_KEY_FALSE(trace_pagefault_key);