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/udf/dir.c | 162 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) create mode 100644 fs/udf/dir.c (limited to 'fs/udf/dir.c') diff --git a/fs/udf/dir.c b/fs/udf/dir.c new file mode 100644 index 000000000..425e3c162 --- /dev/null +++ b/fs/udf/dir.c @@ -0,0 +1,162 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * dir.c + * + * PURPOSE + * Directory handling routines for the OSTA-UDF(tm) filesystem. + * + * COPYRIGHT + * (C) 1998-2004 Ben Fennema + * + * HISTORY + * + * 10/05/98 dgb Split directory operations into its own file + * Implemented directory reads via do_udf_readdir + * 10/06/98 Made directory operations work! + * 11/17/98 Rewrote directory to support ICBTAG_FLAG_AD_LONG + * 11/25/98 blf Rewrote directory handling (readdir+lookup) to support reading + * across blocks. + * 12/12/98 Split out the lookup code to namei.c. bulk of directory + * code now in directory.c:udf_fileident_read. + */ + +#include "udfdecl.h" + +#include +#include +#include +#include +#include +#include +#include + +#include "udf_i.h" +#include "udf_sb.h" + +static int udf_readdir(struct file *file, struct dir_context *ctx) +{ + struct inode *dir = file_inode(file); + loff_t nf_pos, emit_pos = 0; + int flen; + unsigned char *fname = NULL; + int ret = 0; + struct super_block *sb = dir->i_sb; + bool pos_valid = false; + struct udf_fileident_iter iter; + + if (ctx->pos == 0) { + if (!dir_emit_dot(file, ctx)) + return 0; + ctx->pos = 1; + } + nf_pos = (ctx->pos - 1) << 2; + if (nf_pos >= dir->i_size) + goto out; + + /* + * Something changed since last readdir (either lseek was called or dir + * changed)? We need to verify the position correctly points at the + * beginning of some dir entry so that the directory parsing code does + * not get confused. Since UDF does not have any reliable way of + * identifying beginning of dir entry (names are under user control), + * we need to scan the directory from the beginning. + */ + if (!inode_eq_iversion(dir, *(u64 *)file->private_data)) { + emit_pos = nf_pos; + nf_pos = 0; + } else { + pos_valid = true; + } + + fname = kmalloc(UDF_NAME_LEN, GFP_KERNEL); + if (!fname) { + ret = -ENOMEM; + goto out; + } + + for (ret = udf_fiiter_init(&iter, dir, nf_pos); + !ret && iter.pos < dir->i_size; + ret = udf_fiiter_advance(&iter)) { + struct kernel_lb_addr tloc; + udf_pblk_t iblock; + + /* Still not at offset where user asked us to read from? */ + if (iter.pos < emit_pos) + continue; + + /* Update file position only if we got past the current one */ + pos_valid = true; + ctx->pos = (iter.pos >> 2) + 1; + + if (iter.fi.fileCharacteristics & FID_FILE_CHAR_DELETED) { + if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE)) + continue; + } + + if (iter.fi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) { + if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE)) + continue; + } + + if (iter.fi.fileCharacteristics & FID_FILE_CHAR_PARENT) { + if (!dir_emit_dotdot(file, ctx)) + goto out_iter; + continue; + } + + flen = udf_get_filename(sb, iter.name, + iter.fi.lengthFileIdent, fname, UDF_NAME_LEN); + if (flen < 0) + continue; + + tloc = lelb_to_cpu(iter.fi.icb.extLocation); + iblock = udf_get_lb_pblock(sb, &tloc, 0); + if (!dir_emit(ctx, fname, flen, iblock, DT_UNKNOWN)) + goto out_iter; + } + + if (!ret) { + ctx->pos = (iter.pos >> 2) + 1; + pos_valid = true; + } +out_iter: + udf_fiiter_release(&iter); +out: + if (pos_valid) + *(u64 *)file->private_data = inode_query_iversion(dir); + kfree(fname); + + return ret; +} + +static int udf_dir_open(struct inode *inode, struct file *file) +{ + file->private_data = kzalloc(sizeof(u64), GFP_KERNEL); + if (!file->private_data) + return -ENOMEM; + return 0; +} + +static int udf_dir_release(struct inode *inode, struct file *file) +{ + kfree(file->private_data); + return 0; +} + +static loff_t udf_dir_llseek(struct file *file, loff_t offset, int whence) +{ + return generic_llseek_cookie(file, offset, whence, + (u64 *)file->private_data); +} + +/* readdir and lookup functions */ +const struct file_operations udf_dir_operations = { + .open = udf_dir_open, + .release = udf_dir_release, + .llseek = udf_dir_llseek, + .read = generic_read_dir, + .iterate_shared = udf_readdir, + .unlocked_ioctl = udf_ioctl, + .fsync = simple_fsync, + .setlease = generic_setlease, +}; -- cgit v1.3.1