Merge tag 'trace-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:

 - Add new feature to have function graph tracer record the return
   value. Adds a new option: funcgraph-retval ; when set, will show the
   return value of a function in the function graph tracer.

 - Also add the option: funcgraph-retval-hex where if it is not set, and
   the return value is an error code, then it will return the decimal of
   the error code, otherwise it still reports the hex value.

 - Add the file /sys/kernel/tracing/osnoise/per_cpu/cpu<cpu>/timerlat_fd
   That when a application opens it, it becomes the task that the timer
   lat tracer traces. The application can also read this file to find
   out how it's being interrupted.

 - Add the file /sys/kernel/tracing/available_filter_functions_addrs
   that works just the same as available_filter_functions but also shows
   the addresses of the functions like kallsyms, except that it gives
   the address of where the fentry/mcount jump/nop is. This is used by
   BPF to make it easier to attach BPF programs to ftrace hooks.

 - Replace strlcpy with strscpy in the tracing boot code.

* tag 'trace-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Fix warnings when building htmldocs for function graph retval
  riscv: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL
  tracing/boot: Replace strlcpy with strscpy
  tracing/timerlat: Add user-space interface
  tracing/osnoise: Skip running osnoise if all instances are off
  tracing/osnoise: Switch from PF_NO_SETAFFINITY to migrate_disable
  ftrace: Show all functions with addresses in available_filter_functions_addrs
  selftests/ftrace: Add funcgraph-retval test case
  LoongArch: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL
  x86/ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL
  arm64: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL
  tracing: Add documentation for funcgraph-retval and funcgraph-retval-hex
  function_graph: Support recording and printing the return value of function
  fgraph: Add declaration of "struct fgraph_ret_regs"

1 files changed, 44 insertions, 0 deletions

diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-retval.tc b/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-retval.tc
new file mode 100644
index 000000000000..e34c0bdef3ed
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-retval.tc
@@ -0,0 +1,44 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: ftrace - function graph print function return value
+# requires: options/funcgraph-retval options/funcgraph-retval-hex function_graph:tracer
+
+# Make sure that funcgraph-retval works
+
+fail() { # msg
+    echo $1
+    exit_fail
+}
+
+disable_tracing
+clear_trace
+
+# get self PID, can not use $$, because it is PPID
+read PID _ < /proc/self/stat
+
+[ -f set_ftrace_filter ] && echo proc_reg_write > set_ftrace_filter
+[ -f set_ftrace_pid ] && echo ${PID} > set_ftrace_pid
+echo function_graph > current_tracer
+echo 1 > options/funcgraph-retval
+
+set +e
+enable_tracing
+echo > /proc/interrupts
+disable_tracing
+set -e
+
+: "Test printing the error code in signed decimal format"
+echo 0 > options/funcgraph-retval-hex
+count=`cat trace | grep 'proc_reg_write' | grep '= -5' | wc -l`
+if [ $count -eq 0 ]; then
+    fail "Return value can not be printed in signed decimal format"
+fi
+
+: "Test printing the error code in hexadecimal format"
+echo 1 > options/funcgraph-retval-hex
+count=`cat trace | grep 'proc_reg_write' | grep 'fffffffb' | wc -l`
+if [ $count -eq 0 ]; then
+    fail "Return value can not be printed in hexadecimal format"
+fi
+
+exit 0