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Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c54
1 files changed, 37 insertions, 17 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index fb186b9ddf51..31c90fec4158 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1925,8 +1925,16 @@ ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
* when we are adding another op to the rec or removing the
* current one. Thus, if the op is being added, we can
* ignore it because it hasn't attached itself to the rec
- * yet. That means we just need to find the op that has a
- * trampoline and is not beeing added.
+ * yet.
+ *
+ * If an ops is being modified (hooking to different functions)
+ * then we don't care about the new functions that are being
+ * added, just the old ones (that are probably being removed).
+ *
+ * If we are adding an ops to a function that already is using
+ * a trampoline, it needs to be removed (trampolines are only
+ * for single ops connected), then an ops that is not being
+ * modified also needs to be checked.
*/
do_for_each_ftrace_op(op, ftrace_ops_list) {
@@ -1940,17 +1948,23 @@ ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
if (op->flags & FTRACE_OPS_FL_ADDING)
continue;
+
/*
- * If the ops is not being added and has a trampoline,
- * then it must be the one that we want!
+ * If the ops is being modified and is in the old
+ * hash, then it is probably being removed from this
+ * function.
*/
- if (hash_contains_ip(ip, op->func_hash))
- return op;
-
- /* If the ops is being modified, it may be in the old hash. */
if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
hash_contains_ip(ip, &op->old_hash))
return op;
+ /*
+ * If the ops is not being added or modified, and it's
+ * in its normal filter hash, then this must be the one
+ * we want!
+ */
+ if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
+ hash_contains_ip(ip, op->func_hash))
+ return op;
} while_for_each_ftrace_op(op);
@@ -2293,10 +2307,13 @@ static void ftrace_run_update_code(int command)
FTRACE_WARN_ON(ret);
}
-static void ftrace_run_modify_code(struct ftrace_ops *ops, int command)
+static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
+ struct ftrace_hash *old_hash)
{
ops->flags |= FTRACE_OPS_FL_MODIFYING;
+ ops->old_hash.filter_hash = old_hash;
ftrace_run_update_code(command);
+ ops->old_hash.filter_hash = NULL;
ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
}
@@ -3340,7 +3357,7 @@ static struct ftrace_ops trace_probe_ops __read_mostly =
static int ftrace_probe_registered;
-static void __enable_ftrace_function_probe(void)
+static void __enable_ftrace_function_probe(struct ftrace_hash *old_hash)
{
int ret;
int i;
@@ -3348,7 +3365,8 @@ static void __enable_ftrace_function_probe(void)
if (ftrace_probe_registered) {
/* still need to update the function call sites */
if (ftrace_enabled)
- ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS);
+ ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS,
+ old_hash);
return;
}
@@ -3477,13 +3495,14 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
} while_for_each_ftrace_rec();
ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
+
+ __enable_ftrace_function_probe(old_hash);
+
if (!ret)
free_ftrace_hash_rcu(old_hash);
else
count = ret;
- __enable_ftrace_function_probe();
-
out_unlock:
mutex_unlock(&ftrace_lock);
out:
@@ -3764,10 +3783,11 @@ ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
return add_hash_entry(hash, ip);
}
-static void ftrace_ops_update_code(struct ftrace_ops *ops)
+static void ftrace_ops_update_code(struct ftrace_ops *ops,
+ struct ftrace_hash *old_hash)
{
if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled)
- ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS);
+ ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
}
static int
@@ -3813,7 +3833,7 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
old_hash = *orig_hash;
ret = ftrace_hash_move(ops, enable, orig_hash, hash);
if (!ret) {
- ftrace_ops_update_code(ops);
+ ftrace_ops_update_code(ops, old_hash);
free_ftrace_hash_rcu(old_hash);
}
mutex_unlock(&ftrace_lock);
@@ -4058,7 +4078,7 @@ int ftrace_regex_release(struct inode *inode, struct file *file)
ret = ftrace_hash_move(iter->ops, filter_hash,
orig_hash, iter->hash);
if (!ret) {
- ftrace_ops_update_code(iter->ops);
+ ftrace_ops_update_code(iter->ops, old_hash);
free_ftrace_hash_rcu(old_hash);
}
mutex_unlock(&ftrace_lock);