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 --- tools/include/io_uring/mini_liburing.h | 311 +++++++++++++++++++++++++++++++++ 1 file changed, 311 insertions(+) create mode 100644 tools/include/io_uring/mini_liburing.h (limited to 'tools/include/io_uring') diff --git a/tools/include/io_uring/mini_liburing.h b/tools/include/io_uring/mini_liburing.h new file mode 100644 index 000000000..44be4446f --- /dev/null +++ b/tools/include/io_uring/mini_liburing.h @@ -0,0 +1,311 @@ +/* SPDX-License-Identifier: MIT */ + +#include +#include +#include +#include +#include +#include +#include + +struct io_sq_ring { + unsigned int *head; + unsigned int *tail; + unsigned int *ring_mask; + unsigned int *ring_entries; + unsigned int *flags; + unsigned int *array; +}; + +struct io_cq_ring { + unsigned int *head; + unsigned int *tail; + unsigned int *ring_mask; + unsigned int *ring_entries; + struct io_uring_cqe *cqes; +}; + +struct io_uring_sq { + unsigned int *khead; + unsigned int *ktail; + unsigned int *kring_mask; + unsigned int *kring_entries; + unsigned int *kflags; + unsigned int *kdropped; + unsigned int *array; + struct io_uring_sqe *sqes; + + unsigned int sqe_head; + unsigned int sqe_tail; + + size_t ring_sz; +}; + +struct io_uring_cq { + unsigned int *khead; + unsigned int *ktail; + unsigned int *kring_mask; + unsigned int *kring_entries; + unsigned int *koverflow; + struct io_uring_cqe *cqes; + + size_t ring_sz; +}; + +struct io_uring { + struct io_uring_sq sq; + struct io_uring_cq cq; + int ring_fd; + unsigned flags; +}; + +#if defined(__x86_64) || defined(__i386__) +#define read_barrier() __asm__ __volatile__("":::"memory") +#define write_barrier() __asm__ __volatile__("":::"memory") +#else +#define read_barrier() __sync_synchronize() +#define write_barrier() __sync_synchronize() +#endif + +static inline int io_uring_mmap(int fd, struct io_uring_params *p, + struct io_uring_sq *sq, struct io_uring_cq *cq) +{ + size_t size; + void *ptr; + int ret; + + if (p->flags & IORING_SETUP_NO_SQARRAY) { + sq->ring_sz = p->cq_off.cqes; + sq->ring_sz += p->cq_entries * sizeof(struct io_uring_cqe); + } else { + sq->ring_sz = p->sq_off.array; + sq->ring_sz += p->sq_entries * sizeof(unsigned int); + } + + ptr = mmap(0, sq->ring_sz, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_SQ_RING); + if (ptr == MAP_FAILED) + return -errno; + sq->khead = ptr + p->sq_off.head; + sq->ktail = ptr + p->sq_off.tail; + sq->kring_mask = ptr + p->sq_off.ring_mask; + sq->kring_entries = ptr + p->sq_off.ring_entries; + sq->kflags = ptr + p->sq_off.flags; + sq->kdropped = ptr + p->sq_off.dropped; + if (!(p->flags & IORING_SETUP_NO_SQARRAY)) + sq->array = ptr + p->sq_off.array; + + size = p->sq_entries * sizeof(struct io_uring_sqe); + sq->sqes = mmap(0, size, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_SQES); + if (sq->sqes == MAP_FAILED) { + ret = -errno; +err: + munmap(sq->khead, sq->ring_sz); + return ret; + } + + cq->ring_sz = p->cq_off.cqes + p->cq_entries * sizeof(struct io_uring_cqe); + ptr = mmap(0, cq->ring_sz, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_CQ_RING); + if (ptr == MAP_FAILED) { + ret = -errno; + munmap(sq->sqes, p->sq_entries * sizeof(struct io_uring_sqe)); + goto err; + } + cq->khead = ptr + p->cq_off.head; + cq->ktail = ptr + p->cq_off.tail; + cq->kring_mask = ptr + p->cq_off.ring_mask; + cq->kring_entries = ptr + p->cq_off.ring_entries; + cq->koverflow = ptr + p->cq_off.overflow; + cq->cqes = ptr + p->cq_off.cqes; + return 0; +} + +static inline int io_uring_setup(unsigned int entries, + struct io_uring_params *p) +{ + return syscall(__NR_io_uring_setup, entries, p); +} + +static inline int io_uring_enter(int fd, unsigned int to_submit, + unsigned int min_complete, + unsigned int flags, sigset_t *sig) +{ + return syscall(__NR_io_uring_enter, fd, to_submit, min_complete, + flags, sig, _NSIG / 8); +} + +static inline int io_uring_queue_init_params(unsigned int entries, + struct io_uring *ring, + struct io_uring_params *p) +{ + int fd, ret; + + memset(ring, 0, sizeof(*ring)); + + fd = io_uring_setup(entries, p); + if (fd < 0) + return fd; + ret = io_uring_mmap(fd, p, &ring->sq, &ring->cq); + if (!ret) { + ring->ring_fd = fd; + ring->flags = p->flags; + } else { + close(fd); + } + return ret; +} + +static inline int io_uring_queue_init(unsigned int entries, + struct io_uring *ring, + unsigned int flags) +{ + struct io_uring_params p; + + memset(&p, 0, sizeof(p)); + p.flags = flags; + + return io_uring_queue_init_params(entries, ring, &p); +} + +/* Get a sqe */ +static inline struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring) +{ + struct io_uring_sq *sq = &ring->sq; + + if (sq->sqe_tail + 1 - sq->sqe_head > *sq->kring_entries) + return NULL; + return &sq->sqes[sq->sqe_tail++ & *sq->kring_mask]; +} + +static inline int io_uring_wait_cqe(struct io_uring *ring, + struct io_uring_cqe **cqe_ptr) +{ + struct io_uring_cq *cq = &ring->cq; + const unsigned int mask = *cq->kring_mask; + unsigned int head = *cq->khead; + int ret; + + *cqe_ptr = NULL; + do { + read_barrier(); + if (head != *cq->ktail) { + *cqe_ptr = &cq->cqes[head & mask]; + break; + } + ret = io_uring_enter(ring->ring_fd, 0, 1, + IORING_ENTER_GETEVENTS, NULL); + if (ret < 0) + return -errno; + } while (1); + + return 0; +} + +static inline int io_uring_submit(struct io_uring *ring) +{ + struct io_uring_sq *sq = &ring->sq; + const unsigned int mask = *sq->kring_mask; + unsigned int ktail, submitted, to_submit; + int ret; + + read_barrier(); + if (*sq->khead != *sq->ktail) { + submitted = *sq->kring_entries; + goto submit; + } + if (sq->sqe_head == sq->sqe_tail) + return 0; + + ktail = *sq->ktail; + to_submit = sq->sqe_tail - sq->sqe_head; + + if (!(ring->flags & IORING_SETUP_NO_SQARRAY)) { + for (submitted = 0; submitted < to_submit; submitted++) { + read_barrier(); + sq->array[ktail++ & mask] = sq->sqe_head++ & mask; + } + } else { + ktail += to_submit; + sq->sqe_head += to_submit; + submitted = to_submit; + } + + if (!submitted) + return 0; + + if (*sq->ktail != ktail) { + write_barrier(); + *sq->ktail = ktail; + write_barrier(); + } +submit: + ret = io_uring_enter(ring->ring_fd, submitted, 0, + IORING_ENTER_GETEVENTS, NULL); + return ret < 0 ? -errno : ret; +} + +static inline void io_uring_queue_exit(struct io_uring *ring) +{ + struct io_uring_sq *sq = &ring->sq; + + munmap(sq->sqes, *sq->kring_entries * sizeof(struct io_uring_sqe)); + munmap(sq->khead, sq->ring_sz); + close(ring->ring_fd); +} + +/* Prepare and send the SQE */ +static inline void io_uring_prep_cmd(struct io_uring_sqe *sqe, int op, + int sockfd, + int level, int optname, + const void *optval, + int optlen) +{ + memset(sqe, 0, sizeof(*sqe)); + sqe->opcode = (__u8)IORING_OP_URING_CMD; + sqe->fd = sockfd; + sqe->cmd_op = op; + + sqe->level = level; + sqe->optname = optname; + sqe->optval = (unsigned long long)optval; + sqe->optlen = optlen; +} + +static inline int io_uring_register_buffers(struct io_uring *ring, + const struct iovec *iovecs, + unsigned int nr_iovecs) +{ + int ret; + + ret = syscall(__NR_io_uring_register, ring->ring_fd, + IORING_REGISTER_BUFFERS, iovecs, nr_iovecs); + return (ret < 0) ? -errno : ret; +} + +static inline void io_uring_prep_send(struct io_uring_sqe *sqe, int sockfd, + const void *buf, size_t len, int flags) +{ + memset(sqe, 0, sizeof(*sqe)); + sqe->opcode = (__u8)IORING_OP_SEND; + sqe->fd = sockfd; + sqe->addr = (unsigned long)buf; + sqe->len = len; + sqe->msg_flags = (__u32)flags; +} + +static inline void io_uring_prep_sendzc(struct io_uring_sqe *sqe, int sockfd, + const void *buf, size_t len, int flags, + unsigned int zc_flags) +{ + io_uring_prep_send(sqe, sockfd, buf, len, flags); + sqe->opcode = (__u8)IORING_OP_SEND_ZC; + sqe->ioprio = zc_flags; +} + +static inline void io_uring_cqe_seen(struct io_uring *ring) +{ + *(&ring->cq)->khead += 1; + write_barrier(); +} -- cgit v1.3.1