ftrace: convert ftrace_lock from a spinlock to mutex
Impact: clean up
The older versions of ftrace required doing the ftrace list
search under atomic context. Now all the calls are in non-atomic
context. There is no reason to keep the ftrace_lock as a spinlock.
This patch converts it to a mutex.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 45a44c4..4771732 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -61,7 +61,7 @@
*/
static int ftrace_disabled __read_mostly;
-static DEFINE_SPINLOCK(ftrace_lock);
+static DEFINE_MUTEX(ftrace_lock);
static DEFINE_MUTEX(ftrace_sysctl_lock);
static DEFINE_MUTEX(ftrace_start_lock);
@@ -134,8 +134,7 @@
static int __register_ftrace_function(struct ftrace_ops *ops)
{
- /* should not be called from interrupt context */
- spin_lock(&ftrace_lock);
+ mutex_lock(&ftrace_lock);
ops->next = ftrace_list;
/*
@@ -172,7 +171,7 @@
#endif
}
- spin_unlock(&ftrace_lock);
+ mutex_unlock(&ftrace_lock);
return 0;
}
@@ -182,8 +181,7 @@
struct ftrace_ops **p;
int ret = 0;
- /* should not be called from interrupt context */
- spin_lock(&ftrace_lock);
+ mutex_lock(&ftrace_lock);
/*
* If we are removing the last function, then simply point
@@ -224,7 +222,7 @@
}
out:
- spin_unlock(&ftrace_lock);
+ mutex_unlock(&ftrace_lock);
return ret;
}
@@ -233,8 +231,7 @@
{
ftrace_func_t func;
- /* should not be called from interrupt context */
- spin_lock(&ftrace_lock);
+ mutex_lock(&ftrace_lock);
if (ftrace_trace_function == ftrace_stub)
goto out;
@@ -256,7 +253,7 @@
#endif
out:
- spin_unlock(&ftrace_lock);
+ mutex_unlock(&ftrace_lock);
}
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -358,15 +355,12 @@
if (ftrace_disabled || !start)
return;
- /* should not be called from interrupt context */
- spin_lock(&ftrace_lock);
-
+ mutex_lock(&ftrace_lock);
do_for_each_ftrace_rec(pg, rec) {
if ((rec->ip >= s) && (rec->ip < e))
ftrace_free_rec(rec);
} while_for_each_ftrace_rec();
-
- spin_unlock(&ftrace_lock);
+ mutex_unlock(&ftrace_lock);
}
static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
@@ -803,8 +797,7 @@
if (iter->flags & FTRACE_ITER_PRINTALL)
return NULL;
- /* should not be called from interrupt context */
- spin_lock(&ftrace_lock);
+ mutex_lock(&ftrace_lock);
retry:
if (iter->idx >= iter->pg->index) {
if (iter->pg->next) {
@@ -833,7 +826,7 @@
goto retry;
}
}
- spin_unlock(&ftrace_lock);
+ mutex_unlock(&ftrace_lock);
return rec;
}
@@ -962,8 +955,7 @@
struct dyn_ftrace *rec;
unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
- /* should not be called from interrupt context */
- spin_lock(&ftrace_lock);
+ mutex_lock(&ftrace_lock);
if (enable)
ftrace_filtered = 0;
do_for_each_ftrace_rec(pg, rec) {
@@ -971,8 +963,7 @@
continue;
rec->flags &= ~type;
} while_for_each_ftrace_rec();
-
- spin_unlock(&ftrace_lock);
+ mutex_unlock(&ftrace_lock);
}
static int
@@ -1151,8 +1142,7 @@
search_len = strlen(search);
- /* should not be called from interrupt context */
- spin_lock(&ftrace_lock);
+ mutex_lock(&ftrace_lock);
do_for_each_ftrace_rec(pg, rec) {
if (rec->flags & FTRACE_FL_FAILED)
@@ -1171,7 +1161,7 @@
if (enable && (rec->flags & FTRACE_FL_FILTER))
ftrace_filtered = 1;
} while_for_each_ftrace_rec();
- spin_unlock(&ftrace_lock);
+ mutex_unlock(&ftrace_lock);
}
static int
@@ -1218,8 +1208,7 @@
search_len = strlen(search);
}
- /* should not be called from interrupt context */
- spin_lock(&ftrace_lock);
+ mutex_lock(&ftrace_lock);
do_for_each_ftrace_rec(pg, rec) {
if (rec->flags & FTRACE_FL_FAILED)
@@ -1236,7 +1225,7 @@
ftrace_filtered = 1;
} while_for_each_ftrace_rec();
- spin_unlock(&ftrace_lock);
+ mutex_unlock(&ftrace_lock);
}
/*
@@ -1676,9 +1665,7 @@
if (ftrace_disabled)
return -ENODEV;
- /* should not be called from interrupt context */
- spin_lock(&ftrace_lock);
-
+ mutex_lock(&ftrace_lock);
do_for_each_ftrace_rec(pg, rec) {
if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
@@ -1699,7 +1686,7 @@
}
} while_for_each_ftrace_rec();
out:
- spin_unlock(&ftrace_lock);
+ mutex_unlock(&ftrace_lock);
return found ? 0 : -EINVAL;
}