rust: add basic `Task`

It is an abstraction for C's `struct task_struct`. It implements
`AlwaysRefCounted`, so the refcount of the wrapped object is managed
safely on the Rust side.

Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

1 files changed, 19 insertions, 0 deletions

diff --git a/rust/helpers.c b/rust/helpers.c
index 446e3cfdb935..6e5b2c953d36 100644
--- a/rust/helpers.c
+++ b/rust/helpers.c
@@ -24,6 +24,7 @@
 #include <linux/refcount.h>
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
+#include <linux/sched/signal.h>
 
 __noreturn void rust_helper_BUG(void)
 {
@@ -60,6 +61,12 @@ void rust_helper_spin_unlock(spinlock_t *lock)
 }
 EXPORT_SYMBOL_GPL(rust_helper_spin_unlock);
 
+int rust_helper_signal_pending(struct task_struct *t)
+{
+	return signal_pending(t);
+}
+EXPORT_SYMBOL_GPL(rust_helper_signal_pending);
+
 refcount_t rust_helper_REFCOUNT_INIT(int n)
 {
 	return (refcount_t)REFCOUNT_INIT(n);
@@ -96,6 +103,18 @@ long rust_helper_PTR_ERR(__force const void *ptr)
 }
 EXPORT_SYMBOL_GPL(rust_helper_PTR_ERR);
 
+void rust_helper_get_task_struct(struct task_struct *t)
+{
+	get_task_struct(t);
+}
+EXPORT_SYMBOL_GPL(rust_helper_get_task_struct);
+
+void rust_helper_put_task_struct(struct task_struct *t)
+{
+	put_task_struct(t);
+}
+EXPORT_SYMBOL_GPL(rust_helper_put_task_struct);
+
 /*
  * We use `bindgen`'s `--size_t-is-usize` option to bind the C `size_t` type
  * as the Rust `usize` type, so we can use it in contexts where Rust