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 --- include/uapi/asm-generic/msgbuf.h | 49 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 include/uapi/asm-generic/msgbuf.h (limited to 'include/uapi/asm-generic/msgbuf.h') diff --git a/include/uapi/asm-generic/msgbuf.h b/include/uapi/asm-generic/msgbuf.h new file mode 100644 index 000000000..6504d7b74 --- /dev/null +++ b/include/uapi/asm-generic/msgbuf.h @@ -0,0 +1,49 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef __ASM_GENERIC_MSGBUF_H +#define __ASM_GENERIC_MSGBUF_H + +#include +#include + +/* + * generic msqid64_ds structure. + * + * Note extra padding because this structure is passed back and forth + * between kernel and user space. + * + * msqid64_ds was originally meant to be architecture specific, but + * everyone just ended up making identical copies without specific + * optimizations, so we may just as well all use the same one. + * + * 64 bit architectures use a 64-bit long time field here, while + * 32 bit architectures have a pair of unsigned long values. + * On big-endian systems, the lower half is in the wrong place. + * + * Pad space is left for: + * - 2 miscellaneous 32-bit values + */ + +struct msqid64_ds { + struct ipc64_perm msg_perm; +#if __BITS_PER_LONG == 64 + long msg_stime; /* last msgsnd time */ + long msg_rtime; /* last msgrcv time */ + long msg_ctime; /* last change time */ +#else + unsigned long msg_stime; /* last msgsnd time */ + unsigned long msg_stime_high; + unsigned long msg_rtime; /* last msgrcv time */ + unsigned long msg_rtime_high; + unsigned long msg_ctime; /* last change time */ + unsigned long msg_ctime_high; +#endif + unsigned long msg_cbytes; /* current number of bytes on queue */ + unsigned long msg_qnum; /* number of messages in queue */ + unsigned long msg_qbytes; /* max number of bytes on queue */ + __kernel_pid_t msg_lspid; /* pid of last msgsnd */ + __kernel_pid_t msg_lrpid; /* last receive pid */ + unsigned long __unused4; + unsigned long __unused5; +}; + +#endif /* __ASM_GENERIC_MSGBUF_H */ -- cgit v1.3.1