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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /scripts/tracing
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'scripts/tracing')
-rwxr-xr-xscripts/tracing/draw_functrace.py129
-rwxr-xr-xscripts/tracing/ftrace-bisect.sh134
2 files changed, 263 insertions, 0 deletions
diff --git a/scripts/tracing/draw_functrace.py b/scripts/tracing/draw_functrace.py
new file mode 100755
index 000000000..438516bdf
--- /dev/null
+++ b/scripts/tracing/draw_functrace.py
@@ -0,0 +1,129 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: GPL-2.0-only
+
+"""
+Copyright 2008 (c) Frederic Weisbecker <fweisbec@gmail.com>
+
+This script parses a trace provided by the function tracer in
+kernel/trace/trace_functions.c
+The resulted trace is processed into a tree to produce a more human
+view of the call stack by drawing textual but hierarchical tree of
+calls. Only the functions's names and the call time are provided.
+
+Usage:
+ Be sure that you have CONFIG_FUNCTION_TRACER
+ # mount -t debugfs nodev /sys/kernel/debug
+ # echo function > /sys/kernel/debug/tracing/current_tracer
+ $ cat /sys/kernel/debug/tracing/trace_pipe > ~/raw_trace_func
+ Wait some times but not too much, the script is a bit slow.
+ Break the pipe (Ctrl + Z)
+ $ scripts/tracing/draw_functrace.py < ~/raw_trace_func > draw_functrace
+ Then you have your drawn trace in draw_functrace
+"""
+
+
+import sys, re
+
+class CallTree:
+ """ This class provides a tree representation of the functions
+ call stack. If a function has no parent in the kernel (interrupt,
+ syscall, kernel thread...) then it is attached to a virtual parent
+ called ROOT.
+ """
+ ROOT = None
+
+ def __init__(self, func, time = None, parent = None):
+ self._func = func
+ self._time = time
+ if parent is None:
+ self._parent = CallTree.ROOT
+ else:
+ self._parent = parent
+ self._children = []
+
+ def calls(self, func, calltime):
+ """ If a function calls another one, call this method to insert it
+ into the tree at the appropriate place.
+ @return: A reference to the newly created child node.
+ """
+ child = CallTree(func, calltime, self)
+ self._children.append(child)
+ return child
+
+ def getParent(self, func):
+ """ Retrieve the last parent of the current node that
+ has the name given by func. If this function is not
+ on a parent, then create it as new child of root
+ @return: A reference to the parent.
+ """
+ tree = self
+ while tree != CallTree.ROOT and tree._func != func:
+ tree = tree._parent
+ if tree == CallTree.ROOT:
+ child = CallTree.ROOT.calls(func, None)
+ return child
+ return tree
+
+ def __repr__(self):
+ return self.__toString("", True)
+
+ def __toString(self, branch, lastChild):
+ if self._time is not None:
+ s = "%s----%s (%s)\n" % (branch, self._func, self._time)
+ else:
+ s = "%s----%s\n" % (branch, self._func)
+
+ i = 0
+ if lastChild:
+ branch = branch[:-1] + " "
+ while i < len(self._children):
+ if i != len(self._children) - 1:
+ s += "%s" % self._children[i].__toString(branch +\
+ " |", False)
+ else:
+ s += "%s" % self._children[i].__toString(branch +\
+ " |", True)
+ i += 1
+ return s
+
+class BrokenLineException(Exception):
+ """If the last line is not complete because of the pipe breakage,
+ we want to stop the processing and ignore this line.
+ """
+ pass
+
+class CommentLineException(Exception):
+ """ If the line is a comment (as in the beginning of the trace file),
+ just ignore it.
+ """
+ pass
+
+
+def parseLine(line):
+ line = line.strip()
+ if line.startswith("#"):
+ raise CommentLineException
+ m = re.match("[^]]+?\\] +([a-z.]+) +([0-9.]+): (\\w+) <-(\\w+)", line)
+ if m is None:
+ raise BrokenLineException
+ return (m.group(2), m.group(3), m.group(4))
+
+
+def main():
+ CallTree.ROOT = CallTree("Root (Nowhere)", None, None)
+ tree = CallTree.ROOT
+
+ for line in sys.stdin:
+ try:
+ calltime, callee, caller = parseLine(line)
+ except BrokenLineException:
+ break
+ except CommentLineException:
+ continue
+ tree = tree.getParent(caller)
+ tree = tree.calls(callee, calltime)
+
+ print(CallTree.ROOT)
+
+if __name__ == "__main__":
+ main()
diff --git a/scripts/tracing/ftrace-bisect.sh b/scripts/tracing/ftrace-bisect.sh
new file mode 100755
index 000000000..bb4f59262
--- /dev/null
+++ b/scripts/tracing/ftrace-bisect.sh
@@ -0,0 +1,134 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Here's how to use this:
+#
+# This script is used to help find functions that are being traced by function
+# tracer or function graph tracing that causes the machine to reboot, hang, or
+# crash. Here's the steps to take.
+#
+# First, determine if function tracing is working with a single function:
+#
+# (note, if this is a problem with function_graph tracing, then simply
+# replace "function" with "function_graph" in the following steps).
+#
+# # cd /sys/kernel/tracing
+# # echo schedule > set_ftrace_filter
+# # echo function > current_tracer
+#
+# If this works, then we know that something is being traced that shouldn't be.
+#
+# # echo nop > current_tracer
+#
+# Starting with v5.1 this can be done with numbers, making it much faster:
+#
+# The old (slow) way, for kernels before v5.1.
+#
+# [old-way] # cat available_filter_functions > ~/full-file
+#
+# [old-way] *** Note *** this process will take several minutes to update the
+# [old-way] filters. Setting multiple functions is an O(n^2) operation, and we
+# [old-way] are dealing with thousands of functions. So go have coffee, talk
+# [old-way] with your coworkers, read facebook. And eventually, this operation
+# [old-way] will end.
+#
+# The new way (using numbers) is an O(n) operation, and usually takes less than a second.
+#
+# seq `wc -l available_filter_functions | cut -d' ' -f1` > ~/full-file
+#
+# This will create a sequence of numbers that match the functions in
+# available_filter_functions, and when echoing in a number into the
+# set_ftrace_filter file, it will enable the corresponding function in
+# O(1) time. Making enabling all functions O(n) where n is the number of
+# functions to enable.
+#
+# For either the new or old way, the rest of the operations remain the same.
+#
+# # ftrace-bisect ~/full-file ~/test-file ~/non-test-file
+# # cat ~/test-file > set_ftrace_filter
+#
+# # echo function > current_tracer
+#
+# If it crashes, we know that ~/test-file has a bad function.
+#
+# Reboot back to test kernel.
+#
+# # cd /sys/kernel/tracing
+# # mv ~/test-file ~/full-file
+#
+# If it didn't crash.
+#
+# # echo nop > current_tracer
+# # mv ~/non-test-file ~/full-file
+#
+# Get rid of the other test file from previous run (or save them off somewhere).
+# # rm -f ~/test-file ~/non-test-file
+#
+# And start again:
+#
+# # ftrace-bisect ~/full-file ~/test-file ~/non-test-file
+#
+# The good thing is, because this cuts the number of functions in ~/test-file
+# by half, the cat of it into set_ftrace_filter takes half as long each
+# iteration, so don't talk so much at the water cooler the second time.
+#
+# Eventually, if you did this correctly, you will get down to the problem
+# function, and all we need to do is to notrace it.
+#
+# The way to figure out if the problem function is bad, just do:
+#
+# # echo <problem-function> > set_ftrace_notrace
+# # echo > set_ftrace_filter
+# # echo function > current_tracer
+#
+# And if it doesn't crash, we are done.
+#
+# If it does crash, do this again (there's more than one problem function)
+# but you need to echo the problem function(s) into set_ftrace_notrace before
+# enabling function tracing in the above steps. Or if you can compile the
+# kernel, annotate the problem functions with "notrace" and start again.
+#
+
+
+if [ $# -ne 3 ]; then
+ echo 'usage: ftrace-bisect full-file test-file non-test-file'
+ exit
+fi
+
+full=$1
+test=$2
+nontest=$3
+
+x=`cat $full | wc -l`
+if [ $x -eq 1 ]; then
+ echo "There's only one function left, must be the bad one"
+ cat $full
+ exit 0
+fi
+
+let x=$x/2
+let y=$x+1
+
+if [ ! -f $full ]; then
+ echo "$full does not exist"
+ exit 1
+fi
+
+if [ -f $test ]; then
+ echo -n "$test exists, delete it? [y/N]"
+ read a
+ if [ "$a" != "y" -a "$a" != "Y" ]; then
+ exit 1
+ fi
+fi
+
+if [ -f $nontest ]; then
+ echo -n "$nontest exists, delete it? [y/N]"
+ read a
+ if [ "$a" != "y" -a "$a" != "Y" ]; then
+ exit 1
+ fi
+fi
+
+sed -ne "1,${x}p" $full > $test
+sed -ne "$y,\$p" $full > $nontest