Restartable sequences system call (v8)

[deliverable/linux.git] / include / linux / sched.h

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 62c68e513e391372b28c3bf49ded290634d94189..23c5e7b02d9c7b5cdb46e1d345bf9c92c8044fc3 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -59,6 +59,7 @@ struct sched_param {
 #include <linux/gfp.h>
 #include <linux/magic.h>
 #include <linux/cgroup-defs.h>
+#include <linux/rseq.h>
 
 #include <asm/processor.h>
 
@@ -1923,6 +1924,11 @@ struct task_struct {
 #ifdef CONFIG_MMU
        struct task_struct *oom_reaper_list;
 #endif
+#ifdef CONFIG_RSEQ
+       struct rseq __user *rseq;
+       u32 rseq_event_counter;
+       unsigned int rseq_refcount;
+#endif
 /* CPU-specific state of this task */
        struct thread_struct thread;
 /*
@@ -3481,4 +3487,70 @@ void cpufreq_add_update_util_hook(int cpu, struct update_util_data *data,
 void cpufreq_remove_update_util_hook(int cpu);
 #endif /* CONFIG_CPU_FREQ */
 
+#ifdef CONFIG_RSEQ
+static inline void rseq_set_notify_resume(struct task_struct *t)
+{
+       if (t->rseq)
+               set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
+}
+void __rseq_handle_notify_resume(struct pt_regs *regs);
+static inline void rseq_handle_notify_resume(struct pt_regs *regs)
+{
+       if (current->rseq)
+               __rseq_handle_notify_resume(regs);
+}
+/*
+ * If parent process has a registered restartable sequences area, the
+ * child inherits. Only applies when forking a process, not a thread. In
+ * case a parent fork() in the middle of a restartable sequence, set the
+ * resume notifier to force the child to retry.
+ */
+static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
+{
+       if (clone_flags & CLONE_THREAD) {
+               t->rseq = NULL;
+               t->rseq_event_counter = 0;
+               t->rseq_refcount = 0;
+       } else {
+               t->rseq = current->rseq;
+               t->rseq_event_counter = current->rseq_event_counter;
+               t->rseq_refcount = current->rseq_refcount;
+               rseq_set_notify_resume(t);
+       }
+}
+static inline void rseq_execve(struct task_struct *t)
+{
+       t->rseq = NULL;
+       t->rseq_event_counter = 0;
+       t->rseq_refcount = 0;
+}
+static inline void rseq_sched_out(struct task_struct *t)
+{
+       rseq_set_notify_resume(t);
+}
+static inline void rseq_signal_deliver(struct pt_regs *regs)
+{
+       rseq_handle_notify_resume(regs);
+}
+#else
+static inline void rseq_set_notify_resume(struct task_struct *t)
+{
+}
+static inline void rseq_handle_notify_resume(struct pt_regs *regs)
+{
+}
+static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
+{
+}
+static inline void rseq_execve(struct task_struct *t)
+{
+}
+static inline void rseq_sched_out(struct task_struct *t)
+{
+}
+static inline void rseq_signal_deliver(struct pt_regs *regs)
+{
+}
+#endif
+
 #endif