diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/tracepoint.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 1ef5d3a601c..070a42bb892 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -24,6 +24,7 @@ #include <linux/tracepoint.h> #include <linux/err.h> #include <linux/slab.h> +#include <linux/sched.h> extern struct tracepoint __start___tracepoints[]; extern struct tracepoint __stop___tracepoints[]; @@ -577,3 +578,40 @@ static int init_tracepoints(void) __initcall(init_tracepoints); #endif /* CONFIG_MODULES */ + +static DEFINE_MUTEX(regfunc_mutex); +static int sys_tracepoint_refcount; + +void syscall_regfunc(void) +{ + unsigned long flags; + struct task_struct *g, *t; + + mutex_lock(®func_mutex); + if (!sys_tracepoint_refcount) { + read_lock_irqsave(&tasklist_lock, flags); + do_each_thread(g, t) { + set_tsk_thread_flag(t, TIF_SYSCALL_FTRACE); + } while_each_thread(g, t); + read_unlock_irqrestore(&tasklist_lock, flags); + } + sys_tracepoint_refcount++; + mutex_unlock(®func_mutex); +} + +void syscall_unregfunc(void) +{ + unsigned long flags; + struct task_struct *g, *t; + + mutex_lock(®func_mutex); + sys_tracepoint_refcount--; + if (!sys_tracepoint_refcount) { + read_lock_irqsave(&tasklist_lock, flags); + do_each_thread(g, t) { + clear_tsk_thread_flag(t, TIF_SYSCALL_FTRACE); + } while_each_thread(g, t); + read_unlock_irqrestore(&tasklist_lock, flags); + } + mutex_unlock(®func_mutex); +} |