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/testing/selftests/ipc/.gitignore | 3 + tools/testing/selftests/ipc/Makefile | 18 +++ tools/testing/selftests/ipc/config | 2 + tools/testing/selftests/ipc/msgque.c | 256 +++++++++++++++++++++++++++++++++ 4 files changed, 279 insertions(+) create mode 100644 tools/testing/selftests/ipc/.gitignore create mode 100644 tools/testing/selftests/ipc/Makefile create mode 100644 tools/testing/selftests/ipc/config create mode 100644 tools/testing/selftests/ipc/msgque.c (limited to 'tools/testing/selftests/ipc') diff --git a/tools/testing/selftests/ipc/.gitignore b/tools/testing/selftests/ipc/.gitignore new file mode 100644 index 000000000..9ed280e4c --- /dev/null +++ b/tools/testing/selftests/ipc/.gitignore @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only +msgque_test +msgque diff --git a/tools/testing/selftests/ipc/Makefile b/tools/testing/selftests/ipc/Makefile new file mode 100644 index 000000000..fad10f2bb --- /dev/null +++ b/tools/testing/selftests/ipc/Makefile @@ -0,0 +1,18 @@ +# SPDX-License-Identifier: GPL-2.0 +ARCH ?= $(shell uname -m 2>/dev/null || echo not) +override ARCH := $(shell echo $(ARCH) | sed -e s/i.86/i386/) +ifeq ($(ARCH),i386) + override ARCH := x86 + CFLAGS := -DCONFIG_X86_32 -D__i386__ +endif +ifeq ($(ARCH),x86_64) + override ARCH := x86 + CFLAGS := -DCONFIG_X86_64 -D__x86_64__ +endif + +CFLAGS += $(KHDR_INCLUDES) + +TEST_GEN_PROGS := msgque + +include ../lib.mk + diff --git a/tools/testing/selftests/ipc/config b/tools/testing/selftests/ipc/config new file mode 100644 index 000000000..070244710 --- /dev/null +++ b/tools/testing/selftests/ipc/config @@ -0,0 +1,2 @@ +CONFIG_EXPERT=y +CONFIG_CHECKPOINT_RESTORE=y diff --git a/tools/testing/selftests/ipc/msgque.c b/tools/testing/selftests/ipc/msgque.c new file mode 100644 index 000000000..4b4c1abfa --- /dev/null +++ b/tools/testing/selftests/ipc/msgque.c @@ -0,0 +1,256 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include + +#include "kselftest.h" + +#define MAX_MSG_SIZE 32 + +struct msg1 { + int msize; + long mtype; + char mtext[MAX_MSG_SIZE]; +}; + +#define TEST_STRING "Test sysv5 msg" +#define MSG_TYPE 1 + +#define ANOTHER_TEST_STRING "Yet another test sysv5 msg" +#define ANOTHER_MSG_TYPE 26538 + +struct msgque_data { + key_t key; + int msq_id; + int qbytes; + int qnum; + int mode; + struct msg1 *messages; +}; + +int restore_queue(struct msgque_data *msgque) +{ + int fd, ret, id, i; + char buf[32]; + + fd = open("/proc/sys/kernel/msg_next_id", O_WRONLY); + if (fd == -1) { + ksft_test_result_fail("Failed to open /proc/sys/kernel/msg_next_id\n"); + return -errno; + } + sprintf(buf, "%d", msgque->msq_id); + + ret = write(fd, buf, strlen(buf)); + if (ret != strlen(buf)) { + ksft_test_result_fail("Failed to write to /proc/sys/kernel/msg_next_id\n"); + return -errno; + } + + id = msgget(msgque->key, msgque->mode | IPC_CREAT | IPC_EXCL); + if (id == -1) { + ksft_test_result_fail("Failed to create queue\n"); + return -errno; + } + + if (id != msgque->msq_id) { + ksft_test_result_fail("Restored queue has wrong id (%d instead of %d)\n" + , id, msgque->msq_id); + ret = -EFAULT; + goto destroy; + } + + for (i = 0; i < msgque->qnum; i++) { + if (msgsnd(msgque->msq_id, &msgque->messages[i].mtype, + msgque->messages[i].msize, IPC_NOWAIT) != 0) { + ksft_test_result_fail("msgsnd failed (%m)\n"); + ret = -errno; + goto destroy; + } + } + return 0; + +destroy: + if (msgctl(id, IPC_RMID, NULL)) + printf("Failed to destroy queue: %d\n", -errno); + return ret; +} + +int check_and_destroy_queue(struct msgque_data *msgque) +{ + struct msg1 message; + int cnt = 0, ret; + + while (1) { + ret = msgrcv(msgque->msq_id, &message.mtype, MAX_MSG_SIZE, + 0, IPC_NOWAIT); + if (ret < 0) { + if (errno == ENOMSG) + break; + ksft_test_result_fail("Failed to read IPC message: %m\n"); + ret = -errno; + goto err; + } + if (ret != msgque->messages[cnt].msize) { + ksft_test_result_fail("Wrong message size: %d (expected %d)\n", ret, msgque->messages[cnt].msize); + ret = -EINVAL; + goto err; + } + if (message.mtype != msgque->messages[cnt].mtype) { + ksft_test_result_fail("Wrong message type\n"); + ret = -EINVAL; + goto err; + } + if (memcmp(message.mtext, msgque->messages[cnt].mtext, ret)) { + ksft_test_result_fail("Wrong message content\n"); + ret = -EINVAL; + goto err; + } + cnt++; + } + + if (cnt != msgque->qnum) { + ksft_test_result_fail("Wrong message number\n"); + ret = -EINVAL; + goto err; + } + + ret = 0; +err: + if (msgctl(msgque->msq_id, IPC_RMID, NULL)) { + printf("Failed to destroy queue: %d\n", -errno); + return -errno; + } + return ret; +} + +int dump_queue(struct msgque_data *msgque) +{ + struct msqid_ds ds; + int kern_id; + int i, ret; + + for (kern_id = 0; kern_id < 256; kern_id++) { + ret = msgctl(kern_id, MSG_STAT, &ds); + if (ret < 0) { + if (errno == EINVAL) + continue; + ksft_test_result_fail("Failed to get stats for IPC queue with id %d\n", + kern_id); + return -errno; + } + + if (ret == msgque->msq_id) + break; + } + + msgque->messages = malloc(sizeof(struct msg1) * ds.msg_qnum); + if (msgque->messages == NULL) { + ksft_test_result_fail("Failed to get stats for IPC queue\n"); + return -ENOMEM; + } + + msgque->qnum = ds.msg_qnum; + msgque->mode = ds.msg_perm.mode; + msgque->qbytes = ds.msg_qbytes; + + for (i = 0; i < msgque->qnum; i++) { + ret = msgrcv(msgque->msq_id, &msgque->messages[i].mtype, + MAX_MSG_SIZE, i, IPC_NOWAIT | MSG_COPY); + if (ret < 0) { + if (errno == EOPNOTSUPP) + ksft_exit_skip("MSG_COPY not supported\n"); + + ksft_test_result_fail("Failed to copy IPC message: %m (%d)\n", errno); + return -errno; + } + msgque->messages[i].msize = ret; + } + return 0; +} + +int fill_msgque(struct msgque_data *msgque) +{ + struct msg1 msgbuf; + + msgbuf.mtype = MSG_TYPE; + memcpy(msgbuf.mtext, TEST_STRING, sizeof(TEST_STRING)); + if (msgsnd(msgque->msq_id, &msgbuf.mtype, sizeof(TEST_STRING), + IPC_NOWAIT) != 0) { + ksft_test_result_fail("First message send failed (%m)\n"); + return -errno; + } + + msgbuf.mtype = ANOTHER_MSG_TYPE; + memcpy(msgbuf.mtext, ANOTHER_TEST_STRING, sizeof(ANOTHER_TEST_STRING)); + if (msgsnd(msgque->msq_id, &msgbuf.mtype, sizeof(ANOTHER_TEST_STRING), + IPC_NOWAIT) != 0) { + ksft_test_result_fail("Second message send failed (%m)\n"); + return -errno; + } + return 0; +} + +int main(int argc, char **argv) +{ + int err; + struct msgque_data msgque; + + if (getuid() != 0) + ksft_exit_skip("Please run the test as root - Exiting.\n"); + + msgque.key = ftok(argv[0], 822155650); + if (msgque.key == -1) { + ksft_test_result_fail("Can't make key: %d\n", -errno); + ksft_exit_fail(); + } + + msgque.msq_id = msgget(msgque.key, IPC_CREAT | IPC_EXCL | 0666); + if (msgque.msq_id == -1) { + err = -errno; + ksft_test_result_fail("Can't create queue: %d\n", err); + goto err_out; + } + + err = fill_msgque(&msgque); + if (err) { + ksft_test_result_fail("Failed to fill queue: %d\n", err); + goto err_destroy; + } + + err = dump_queue(&msgque); + if (err) { + ksft_test_result_fail("Failed to dump queue: %d\n", err); + goto err_destroy; + } + + err = check_and_destroy_queue(&msgque); + if (err) { + ksft_test_result_fail("Failed to check and destroy queue: %d\n", err); + goto err_out; + } + + err = restore_queue(&msgque); + if (err) { + ksft_test_result_fail("Failed to restore queue: %d\n", err); + goto err_destroy; + } + + err = check_and_destroy_queue(&msgque); + if (err) { + ksft_test_result_fail("Failed to test queue: %d\n", err); + goto err_out; + } + ksft_exit_pass(); + +err_destroy: + if (msgctl(msgque.msq_id, IPC_RMID, NULL)) { + printf("Failed to destroy queue: %d\n", -errno); + ksft_exit_fail(); + } +err_out: + ksft_exit_fail(); +} -- cgit v1.3.1