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/fs_dirent.c | 105 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 105 insertions(+) create mode 100644 fs/fs_dirent.c (limited to 'fs/fs_dirent.c') diff --git a/fs/fs_dirent.c b/fs/fs_dirent.c new file mode 100644 index 000000000..e5e08f213 --- /dev/null +++ b/fs/fs_dirent.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include + +/* + * fs on-disk file type to dirent file type conversion + */ +static const unsigned char fs_dtype_by_ftype[FT_MAX] = { + [FT_UNKNOWN] = DT_UNKNOWN, + [FT_REG_FILE] = DT_REG, + [FT_DIR] = DT_DIR, + [FT_CHRDEV] = DT_CHR, + [FT_BLKDEV] = DT_BLK, + [FT_FIFO] = DT_FIFO, + [FT_SOCK] = DT_SOCK, + [FT_SYMLINK] = DT_LNK +}; + +/** + * fs_ftype_to_dtype() - fs on-disk file type to dirent type. + * @filetype: The on-disk file type to convert. + * + * This function converts the on-disk file type value (FT_*) to the directory + * entry type (DT_*). + * + * Context: Any context. + * Return: + * * DT_UNKNOWN - Unknown type + * * DT_FIFO - FIFO + * * DT_CHR - Character device + * * DT_DIR - Directory + * * DT_BLK - Block device + * * DT_REG - Regular file + * * DT_LNK - Symbolic link + * * DT_SOCK - Local-domain socket + */ +unsigned char fs_ftype_to_dtype(unsigned int filetype) +{ + if (filetype >= FT_MAX) + return DT_UNKNOWN; + + return fs_dtype_by_ftype[filetype]; +} +EXPORT_SYMBOL_GPL(fs_ftype_to_dtype); + +/* + * dirent file type to fs on-disk file type conversion + * Values not initialized explicitly are FT_UNKNOWN (0). + */ +static const unsigned char fs_ftype_by_dtype[DT_MAX] = { + [DT_REG] = FT_REG_FILE, + [DT_DIR] = FT_DIR, + [DT_LNK] = FT_SYMLINK, + [DT_CHR] = FT_CHRDEV, + [DT_BLK] = FT_BLKDEV, + [DT_FIFO] = FT_FIFO, + [DT_SOCK] = FT_SOCK, +}; + +/** + * fs_umode_to_ftype() - file mode to on-disk file type. + * @mode: The file mode to convert. + * + * This function converts the file mode value to the on-disk file type (FT_*). + * + * Context: Any context. + * Return: + * * FT_UNKNOWN - Unknown type + * * FT_REG_FILE - Regular file + * * FT_DIR - Directory + * * FT_CHRDEV - Character device + * * FT_BLKDEV - Block device + * * FT_FIFO - FIFO + * * FT_SOCK - Local-domain socket + * * FT_SYMLINK - Symbolic link + */ +unsigned char fs_umode_to_ftype(umode_t mode) +{ + return fs_ftype_by_dtype[S_DT(mode)]; +} +EXPORT_SYMBOL_GPL(fs_umode_to_ftype); + +/** + * fs_umode_to_dtype() - file mode to dirent file type. + * @mode: The file mode to convert. + * + * This function converts the file mode value to the directory + * entry type (DT_*). + * + * Context: Any context. + * Return: + * * DT_UNKNOWN - Unknown type + * * DT_FIFO - FIFO + * * DT_CHR - Character device + * * DT_DIR - Directory + * * DT_BLK - Block device + * * DT_REG - Regular file + * * DT_LNK - Symbolic link + * * DT_SOCK - Local-domain socket + */ +unsigned char fs_umode_to_dtype(umode_t mode) +{ + return fs_ftype_to_dtype(fs_umode_to_ftype(mode)); +} +EXPORT_SYMBOL_GPL(fs_umode_to_dtype); -- cgit v1.3.1