From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- scripts/objdiff | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) create mode 100755 scripts/objdiff (limited to 'scripts/objdiff') diff --git a/scripts/objdiff b/scripts/objdiff new file mode 100755 index 000000000..0685bc3ce --- /dev/null +++ b/scripts/objdiff @@ -0,0 +1,162 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0-only + +# objdiff - a small script for validating that a commit or series of commits +# didn't change object code. +# +# Copyright 2014, Jason Cooper +# + +# usage example: +# +# $ git checkout COMMIT_A +# $ +# $ ./scripts/objdiff record path/to/*.o +# +# $ git checkout COMMIT_B +# $ +# $ ./scripts/objdiff record path/to/*.o +# +# $ ./scripts/objdiff diff COMMIT_A COMMIT_B +# $ + +# And to clean up (everything is in .objdiff/*) +# $ ./scripts/objdiff clean all +# +# Note: 'make mrproper' will also remove .objdiff + +SRCTREE=$(cd $(git rev-parse --show-toplevel 2>/dev/null); pwd) + +if [ -z "$SRCTREE" ]; then + echo >&2 "ERROR: Not a git repository." + exit 1 +fi + +TMPD=$SRCTREE/.objdiff + +usage() { + echo >&2 "Usage: $0 " + echo >&2 " record " + echo >&2 " diff " + echo >&2 " clean all | " + exit 1 +} + +get_output_dir() { + dir=${1%/*} + + if [ "$dir" = "$1" ]; then + dir=. + fi + + dir=$(cd $dir; pwd) + + echo $TMPD/$CMT${dir#$SRCTREE} +} + +do_objdump() { + dir=$(get_output_dir $1) + base=${1##*/} + stripped=$dir/${base%.o}.stripped + dis=$dir/${base%.o}.dis + + [ ! -d "$dir" ] && mkdir -p $dir + + # remove addresses for a cleaner diff + # http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and + $STRIP -g $1 -R __bug_table -R .note -R .comment -o $stripped + $OBJDUMP -D $stripped | sed -e "s/^[[:space:]]\+[0-9a-f]\+//" -e "s:^$stripped:$1:" > $dis +} + +dorecord() { + [ $# -eq 0 ] && usage + + FILES="$*" + + CMT="`git rev-parse --short HEAD`" + + STRIP="${CROSS_COMPILE}strip" + OBJDUMP="${CROSS_COMPILE}objdump" + + for d in $FILES; do + if [ -d "$d" ]; then + for f in $(find $d -name '*.o') + do + do_objdump $f + done + else + do_objdump $d + fi + done +} + +dodiff() { + [ $# -ne 2 ] && [ $# -ne 0 ] && usage + + if [ $# -eq 0 ]; then + SRC="`git rev-parse --short HEAD^`" + DST="`git rev-parse --short HEAD`" + else + SRC="`git rev-parse --short $1`" + DST="`git rev-parse --short $2`" + fi + + DIFF="`which colordiff`" + + if [ ${#DIFF} -eq 0 ] || [ ! -x "$DIFF" ]; then + DIFF="`which diff`" + fi + + SRCD="$TMPD/$SRC" + DSTD="$TMPD/$DST" + + if [ ! -d "$SRCD" ]; then + echo >&2 "ERROR: $SRCD doesn't exist" + exit 1 + fi + + if [ ! -d "$DSTD" ]; then + echo >&2 "ERROR: $DSTD doesn't exist" + exit 1 + fi + + $DIFF -Nurd $SRCD $DSTD +} + +doclean() { + [ $# -eq 0 ] && usage + [ $# -gt 1 ] && usage + + if [ "x$1" = "xall" ]; then + rm -rf $TMPD/* + else + CMT="`git rev-parse --short $1`" + + if [ -d "$TMPD/$CMT" ]; then + rm -rf $TMPD/$CMT + else + echo >&2 "$CMT not found" + fi + fi +} + +[ $# -eq 0 ] && usage + +case "$1" in + record) + shift + dorecord $* + ;; + diff) + shift + dodiff $* + ;; + clean) + shift + doclean $* + ;; + *) + echo >&2 "Unrecognized command '$1'" + exit 1 + ;; +esac -- cgit v1.3.1