diff options
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/Kconfig | 9 | ||||
| -rw-r--r-- | samples/hung_task/hung_task_tests.c | 81 | ||||
| -rw-r--r-- | samples/rust/rust_configfs.rs | 2 | ||||
| -rw-r--r-- | samples/rust/rust_driver_auxiliary.rs | 2 | ||||
| -rw-r--r-- | samples/rust/rust_misc_device.rs | 2 | ||||
| -rw-r--r-- | samples/rust/rust_print_main.rs | 2 |
6 files changed, 83 insertions, 15 deletions
diff --git a/samples/Kconfig b/samples/Kconfig index ffef99950206..6e072a5f1ed8 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -54,7 +54,7 @@ config SAMPLE_FTRACE_OPS measures the time taken to invoke one function a number of times. config SAMPLE_TRACE_ARRAY - tristate "Build sample module for kernel access to Ftrace instancess" + tristate "Build sample module for kernel access to Ftrace instances" depends on EVENT_TRACING && m help This builds a module that demonstrates the use of various APIs to @@ -316,10 +316,9 @@ config SAMPLE_HUNG_TASK depends on DETECT_HUNG_TASK && DEBUG_FS help Build a module that provides debugfs files (e.g., mutex, semaphore, - etc.) under <debugfs>/hung_task. If user reads one of these files, - it will sleep long time (256 seconds) with holding a lock. Thus, - if 2 or more processes read the same file concurrently, it will - be detected by the hung_task watchdog. + rw_semaphore_read, rw_semaphore_write) under <debugfs>/hung_task. + Reading these files with multiple processes triggers hung task + detection by holding locks for a long time (256 seconds). source "samples/rust/Kconfig" diff --git a/samples/hung_task/hung_task_tests.c b/samples/hung_task/hung_task_tests.c index a5c09bd3a47d..0360ec916890 100644 --- a/samples/hung_task/hung_task_tests.c +++ b/samples/hung_task/hung_task_tests.c @@ -4,11 +4,12 @@ * semaphore, etc. * * Usage: Load this module and read `<debugfs>/hung_task/mutex`, - * `<debugfs>/hung_task/semaphore`, etc., with 2 or more processes. + * `<debugfs>/hung_task/semaphore`, `<debugfs>/hung_task/rw_semaphore_read`, + * `<debugfs>/hung_task/rw_semaphore_write`, etc., with 2 or more processes. * * This is for testing kernel hung_task error messages with various locking - * mechanisms (e.g., mutex, semaphore, etc.). Note that this may freeze - * your system or cause a panic. Use only for testing purposes. + * mechanisms (e.g., mutex, semaphore, rw_semaphore_read, rw_semaphore_write, etc.). + * Note that this may freeze your system or cause a panic. Use only for testing purposes. */ #include <linux/debugfs.h> @@ -17,21 +18,29 @@ #include <linux/module.h> #include <linux/mutex.h> #include <linux/semaphore.h> +#include <linux/rwsem.h> -#define HUNG_TASK_DIR "hung_task" -#define HUNG_TASK_MUTEX_FILE "mutex" -#define HUNG_TASK_SEM_FILE "semaphore" -#define SLEEP_SECOND 256 +#define HUNG_TASK_DIR "hung_task" +#define HUNG_TASK_MUTEX_FILE "mutex" +#define HUNG_TASK_SEM_FILE "semaphore" +#define HUNG_TASK_RWSEM_READ_FILE "rw_semaphore_read" +#define HUNG_TASK_RWSEM_WRITE_FILE "rw_semaphore_write" +#define SLEEP_SECOND 256 static const char dummy_string[] = "This is a dummy string."; static DEFINE_MUTEX(dummy_mutex); static DEFINE_SEMAPHORE(dummy_sem, 1); +static DECLARE_RWSEM(dummy_rwsem); static struct dentry *hung_task_dir; /* Mutex-based read function */ static ssize_t read_dummy_mutex(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { + /* Check if data is already read */ + if (*ppos >= sizeof(dummy_string)) + return 0; + /* Second task waits on mutex, entering uninterruptible sleep */ guard(mutex)(&dummy_mutex); @@ -46,6 +55,10 @@ static ssize_t read_dummy_mutex(struct file *file, char __user *user_buf, static ssize_t read_dummy_semaphore(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { + /* Check if data is already read */ + if (*ppos >= sizeof(dummy_string)) + return 0; + /* Second task waits on semaphore, entering uninterruptible sleep */ down(&dummy_sem); @@ -58,6 +71,46 @@ static ssize_t read_dummy_semaphore(struct file *file, char __user *user_buf, sizeof(dummy_string)); } +/* Read-write semaphore read function */ +static ssize_t read_dummy_rwsem_read(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + /* Check if data is already read */ + if (*ppos >= sizeof(dummy_string)) + return 0; + + /* Acquires read lock, allowing concurrent readers but blocks if write lock is held */ + down_read(&dummy_rwsem); + + /* Sleeps here, potentially triggering hung task detection if lock is held too long */ + msleep_interruptible(SLEEP_SECOND * 1000); + + up_read(&dummy_rwsem); + + return simple_read_from_buffer(user_buf, count, ppos, dummy_string, + sizeof(dummy_string)); +} + +/* Read-write semaphore write function */ +static ssize_t read_dummy_rwsem_write(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + /* Check if data is already read */ + if (*ppos >= sizeof(dummy_string)) + return 0; + + /* Acquires exclusive write lock, blocking all other readers and writers */ + down_write(&dummy_rwsem); + + /* Sleeps here, potentially triggering hung task detection if lock is held too long */ + msleep_interruptible(SLEEP_SECOND * 1000); + + up_write(&dummy_rwsem); + + return simple_read_from_buffer(user_buf, count, ppos, dummy_string, + sizeof(dummy_string)); +} + /* File operations for mutex */ static const struct file_operations hung_task_mutex_fops = { .read = read_dummy_mutex, @@ -68,6 +121,16 @@ static const struct file_operations hung_task_sem_fops = { .read = read_dummy_semaphore, }; +/* File operations for rw_semaphore read */ +static const struct file_operations hung_task_rwsem_read_fops = { + .read = read_dummy_rwsem_read, +}; + +/* File operations for rw_semaphore write */ +static const struct file_operations hung_task_rwsem_write_fops = { + .read = read_dummy_rwsem_write, +}; + static int __init hung_task_tests_init(void) { hung_task_dir = debugfs_create_dir(HUNG_TASK_DIR, NULL); @@ -79,6 +142,10 @@ static int __init hung_task_tests_init(void) &hung_task_mutex_fops); debugfs_create_file(HUNG_TASK_SEM_FILE, 0400, hung_task_dir, NULL, &hung_task_sem_fops); + debugfs_create_file(HUNG_TASK_RWSEM_READ_FILE, 0400, hung_task_dir, NULL, + &hung_task_rwsem_read_fops); + debugfs_create_file(HUNG_TASK_RWSEM_WRITE_FILE, 0400, hung_task_dir, NULL, + &hung_task_rwsem_write_fops); return 0; } diff --git a/samples/rust/rust_configfs.rs b/samples/rust/rust_configfs.rs index 60ddbe62cda3..af04bfa35cb2 100644 --- a/samples/rust/rust_configfs.rs +++ b/samples/rust/rust_configfs.rs @@ -14,7 +14,7 @@ use kernel::sync::Mutex; module! { type: RustConfigfs, name: "rust_configfs", - author: "Rust for Linux Contributors", + authors: ["Rust for Linux Contributors"], description: "Rust configfs sample", license: "GPL", } diff --git a/samples/rust/rust_driver_auxiliary.rs b/samples/rust/rust_driver_auxiliary.rs index b25628604a93..f2a820683fc3 100644 --- a/samples/rust/rust_driver_auxiliary.rs +++ b/samples/rust/rust_driver_auxiliary.rs @@ -113,7 +113,7 @@ impl InPlaceModule for SampleModule { module! { type: SampleModule, name: "rust_driver_auxiliary", - author: "Danilo Krummrich", + authors: ["Danilo Krummrich"], description: "Rust auxiliary driver", license: "GPL v2", } diff --git a/samples/rust/rust_misc_device.rs b/samples/rust/rust_misc_device.rs index c881fd6dbd08..e7ab77448f75 100644 --- a/samples/rust/rust_misc_device.rs +++ b/samples/rust/rust_misc_device.rs @@ -176,6 +176,8 @@ impl MiscDevice for RustMiscDevice { fn ioctl(me: Pin<&RustMiscDevice>, _file: &File, cmd: u32, arg: usize) -> Result<isize> { dev_info!(me.dev, "IOCTLing Rust Misc Device Sample\n"); + // Treat the ioctl argument as a user pointer. + let arg = UserPtr::from_addr(arg); let size = _IOC_SIZE(cmd); match cmd { diff --git a/samples/rust/rust_print_main.rs b/samples/rust/rust_print_main.rs index 8ea95e8c2f36..4095c72afeab 100644 --- a/samples/rust/rust_print_main.rs +++ b/samples/rust/rust_print_main.rs @@ -40,7 +40,7 @@ fn arc_print() -> Result { // behaviour, contract or protocol on both `i32` and `&str` into a single `Arc` of // type `Arc<dyn Display>`. - use core::fmt::Display; + use kernel::fmt::Display; fn arc_dyn_print(arc: &Arc<dyn Display>) { pr_info!("Arc<dyn Display> says {arc}"); } |