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 --- fs/ext4/Kconfig | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) create mode 100644 fs/ext4/Kconfig (limited to 'fs/ext4/Kconfig') diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig new file mode 100644 index 000000000..01873c2a3 --- /dev/null +++ b/fs/ext4/Kconfig @@ -0,0 +1,92 @@ +# SPDX-License-Identifier: GPL-2.0-only +config EXT4_FS + tristate "The Extended 4 (ext4) filesystem" + select BUFFER_HEAD + select JBD2 + select CRC16 + select CRC32 + select FS_IOMAP + select FS_ENCRYPTION_ALGS if FS_ENCRYPTION + help + This is the next generation of the ext3 filesystem. + + Unlike the change from ext2 filesystem to ext3 filesystem, + the on-disk format of ext4 is not forwards compatible with + ext3; it is based on extent maps and it supports 48-bit + physical block numbers. The ext4 filesystem also supports delayed + allocation, persistent preallocation, high resolution time stamps, + and a number of other features to improve performance and speed + up fsck time. For more information, please see the web pages at + http://ext4.wiki.kernel.org. + + The ext4 filesystem supports mounting an ext3 filesystem; while there + are some performance gains from the delayed allocation and inode + table readahead, the best performance gains require enabling ext4 + features in the filesystem using tune2fs, or formatting a new + filesystem as an ext4 filesystem initially. Without explicit enabling + of ext4 features, the on disk filesystem format stays fully backward + compatible. + + To compile this file system support as a module, choose M here. The + module will be called ext4. + + If unsure, say N. + +config EXT4_USE_FOR_EXT2 + bool "Use ext4 for ext2 file systems" + depends on EXT4_FS + depends on EXT2_FS=n + default y + help + Allow the ext4 file system driver code to be used for ext2 + file system mounts. This allows users to reduce their + compiled kernel size by using one file system driver for + ext2, ext3, and ext4 file systems. + +config EXT4_FS_POSIX_ACL + bool "Ext4 POSIX Access Control Lists" + depends on EXT4_FS + select FS_POSIX_ACL + help + POSIX Access Control Lists (ACLs) support permissions for users and + groups beyond the owner/group/world scheme. + + If you don't know what Access Control Lists are, say N + +config EXT4_FS_SECURITY + bool "Ext4 Security Labels" + depends on EXT4_FS + help + Security labels support alternative access control models + implemented by security modules like SELinux. This option + enables an extended attribute handler for file security + labels in the ext4 filesystem. + + If you are not using a security module that requires using + extended attributes for file security labels, say N. + +config EXT4_DEBUG + bool "Ext4 debugging support" + depends on EXT4_FS + help + Enables run-time debugging support for the ext4 filesystem. + + If you select Y here, then you will be able to turn on debugging + using dynamic debug control for mb_debug() / ext_debug() msgs. + +config EXT4_KUNIT_TESTS + tristate "KUnit tests for ext4" if !KUNIT_ALL_TESTS + depends on EXT4_FS && KUNIT + default KUNIT_ALL_TESTS + help + This builds the ext4 KUnit tests. + + KUnit tests run during boot and output the results to the debug log + in TAP format (https://testanything.org/). Only useful for kernel devs + running KUnit test harness and are not for inclusion into a production + build. + + For more information on KUnit and unit tests in general please refer + to the KUnit documentation in Documentation/dev-tools/kunit/. + + If unsure, say N. -- cgit v1.3.1