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/ntfs/debug.c | 171 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 171 insertions(+) create mode 100644 fs/ntfs/debug.c (limited to 'fs/ntfs/debug.c') diff --git a/fs/ntfs/debug.c b/fs/ntfs/debug.c new file mode 100644 index 000000000..f241ebc97 --- /dev/null +++ b/fs/ntfs/debug.c @@ -0,0 +1,171 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * NTFS kernel debug support. + * + * Copyright (c) 2001-2004 Anton Altaparmakov + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include "debug.h" + +/* + * __ntfs_warning - output a warning to the syslog + * @function: name of function outputting the warning + * @sb: super block of mounted ntfs filesystem + * @fmt: warning string containing format specifications + * @...: a variable number of arguments specified in @fmt + * + * Outputs a warning to the syslog for the mounted ntfs filesystem described + * by @sb. + * + * @fmt and the corresponding @... is printf style format string containing + * the warning string and the corresponding format arguments, respectively. + * + * @function is the name of the function from which __ntfs_warning is being + * called. + * + * Note, you should be using debug.h::ntfs_warning(@sb, @fmt, @...) instead + * as this provides the @function parameter automatically. + */ +void __ntfs_warning(const char *function, const struct super_block *sb, + const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + int flen = 0; + + if (function) + flen = strlen(function); + va_start(args, fmt); + vaf.fmt = fmt; + vaf.va = &args; +#ifdef DEBUG + if (sb) + pr_warn("(device %s): %s(): %pV\n", + sb->s_id, flen ? function : "", &vaf); + else + pr_warn("%s(): %pV\n", flen ? function : "", &vaf); +#else + if (sb) + pr_warn_ratelimited("(device %s): %s(): %pV\n", + sb->s_id, flen ? function : "", &vaf); + else + pr_warn_ratelimited("%s(): %pV\n", flen ? function : "", &vaf); +#endif + va_end(args); +} + +/* + * __ntfs_error - output an error to the syslog + * @function: name of function outputting the error + * @sb: super block of mounted ntfs filesystem + * @fmt: error string containing format specifications + * @...: a variable number of arguments specified in @fmt + * + * Outputs an error to the syslog for the mounted ntfs filesystem described + * by @sb. + * + * @fmt and the corresponding @... is printf style format string containing + * the error string and the corresponding format arguments, respectively. + * + * @function is the name of the function from which __ntfs_error is being + * called. + * + * Note, you should be using debug.h::ntfs_error(@sb, @fmt, @...) instead + * as this provides the @function parameter automatically. + */ +void __ntfs_error(const char *function, struct super_block *sb, + const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + int flen = 0; + + if (function) + flen = strlen(function); + va_start(args, fmt); + vaf.fmt = fmt; + vaf.va = &args; +#ifdef DEBUG + if (sb) + pr_err("(device %s): %s(): %pV\n", + sb->s_id, flen ? function : "", &vaf); + else + pr_err("%s(): %pV\n", flen ? function : "", &vaf); +#else + if (sb) + pr_err_ratelimited("(device %s): %s(): %pV\n", + sb->s_id, flen ? function : "", &vaf); + else + pr_err_ratelimited("%s(): %pV\n", flen ? function : "", &vaf); +#endif + va_end(args); + + if (sb) + ntfs_handle_error(sb); +} + +#ifdef DEBUG + +/* If 1, output debug messages, and if 0, don't. */ +int debug_msgs; + +void __ntfs_debug(const char *file, int line, const char *function, + const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + int flen = 0; + + if (!debug_msgs) + return; + if (function) + flen = strlen(function); + va_start(args, fmt); + vaf.fmt = fmt; + vaf.va = &args; + pr_debug("(%s, %d): %s(): %pV", file, line, flen ? function : "", &vaf); + va_end(args); +} + +/* Dump a runlist. Caller has to provide synchronisation for @rl. */ +void ntfs_debug_dump_runlist(const struct runlist_element *rl) +{ + int i; + const char *lcn_str[5] = { "LCN_DELALLOC ", "LCN_HOLE ", + "LCN_RL_NOT_MAPPED", "LCN_ENOENT ", + "LCN_unknown " }; + + if (!debug_msgs) + return; + pr_debug("Dumping runlist (values in hex):\n"); + if (!rl) { + pr_debug("Run list not present.\n"); + return; + } + pr_debug("VCN LCN Run length\n"); + for (i = 0; ; i++) { + s64 lcn = (rl + i)->lcn; + + if (lcn < 0) { + int index = -lcn - 1; + + if (index > -LCN_ENOENT - 1) + index = 3; + pr_debug("%-16Lx %s %-16Lx%s\n", + (long long)(rl + i)->vcn, lcn_str[index], + (long long)(rl + i)->length, + (rl + i)->length ? "" : + " (runlist end)"); + } else + pr_debug("%-16Lx %-16Lx %-16Lx%s\n", + (long long)(rl + i)->vcn, + (long long)(rl + i)->lcn, + (long long)(rl + i)->length, + (rl + i)->length ? "" : + " (runlist end)"); + if (!(rl + i)->length) + break; + } +} + +#endif -- cgit v1.3.1