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| author | Eric W. Biederman <ebiederm@xmission.com> | 2021-11-22 10:27:36 -0600 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2021-12-13 12:04:45 -0600 |
| commit | bbda86e988d4c124e4cfa816291cbd583ae8bfb1 (patch) | |
| tree | b0d36a233c14df7e3a76cf608a3a956ac58b90a7 | |
| parent | eb55e716ac1aa0de13ef5abbf1479d995582d967 (diff) | |
| download | lwn-bbda86e988d4c124e4cfa816291cbd583ae8bfb1.tar.gz lwn-bbda86e988d4c124e4cfa816291cbd583ae8bfb1.zip | |
exit: Implement kthread_exit
The way the per task_struct exit_code is used by kernel threads is not
quite compatible how it is used by userspace applications. The low
byte of the userspace exit_code value encodes the exit signal. While
kthreads just use the value as an int holding ordinary kernel function
exit status like -EPERM.
Add kthread_exit to clearly separate the two kinds of uses.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| -rw-r--r-- | include/linux/kthread.h | 1 | ||||
| -rw-r--r-- | kernel/kthread.c | 23 | ||||
| -rw-r--r-- | tools/objtool/check.c | 1 |
3 files changed, 21 insertions, 4 deletions
diff --git a/include/linux/kthread.h b/include/linux/kthread.h index 346b0f269161..22c43d419687 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -70,6 +70,7 @@ void *kthread_probe_data(struct task_struct *k); int kthread_park(struct task_struct *k); void kthread_unpark(struct task_struct *k); void kthread_parkme(void); +void kthread_exit(long result) __noreturn; int kthreadd(void *unused); extern struct task_struct *kthreadd_task; diff --git a/kernel/kthread.c b/kernel/kthread.c index 7113003fab63..77b7c3f23f18 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -268,6 +268,21 @@ void kthread_parkme(void) } EXPORT_SYMBOL_GPL(kthread_parkme); +/** + * kthread_exit - Cause the current kthread return @result to kthread_stop(). + * @result: The integer value to return to kthread_stop(). + * + * While kthread_exit can be called directly, it exists so that + * functions which do some additional work in non-modular code such as + * module_put_and_kthread_exit can be implemented. + * + * Does not return. + */ +void __noreturn kthread_exit(long result) +{ + do_exit(result); +} + static int kthread(void *_create) { static const struct sched_param param = { .sched_priority = 0 }; @@ -286,13 +301,13 @@ static int kthread(void *_create) done = xchg(&create->done, NULL); if (!done) { kfree(create); - do_exit(-EINTR); + kthread_exit(-EINTR); } if (!self) { create->result = ERR_PTR(-ENOMEM); complete(done); - do_exit(-ENOMEM); + kthread_exit(-ENOMEM); } self->threadfn = threadfn; @@ -326,7 +341,7 @@ static int kthread(void *_create) __kthread_parkme(self); ret = threadfn(data); } - do_exit(ret); + kthread_exit(ret); } /* called from kernel_clone() to get node information for about to be created task */ @@ -627,7 +642,7 @@ EXPORT_SYMBOL_GPL(kthread_park); * instead of calling wake_up_process(): the thread will exit without * calling threadfn(). * - * If threadfn() may call do_exit() itself, the caller must ensure + * If threadfn() may call kthread_exit() itself, the caller must ensure * task_struct can't go away. * * Returns the result of threadfn(), or %-EINTR if wake_up_process() diff --git a/tools/objtool/check.c b/tools/objtool/check.c index e6ab5687770b..90108fe5610d 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -168,6 +168,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, "panic", "do_exit", "do_task_dead", + "kthread_exit", "make_task_dead", "__module_put_and_exit", "complete_and_exit", |