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authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2016-11-14 16:31:49 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-11-26 09:56:53 +0100
commit8844024c883972fe9ce983a60cd9cc55cfb073ae (patch)
tree7c2808889c4556b265e845e629d8b9f3d9936e2a
parentc5d20ce0b459b6e2d00f58b599543eb0e8e725e4 (diff)
ftrace: Add more checks for FTRACE_FL_DISABLED in processing ip records
commit 546fece4eae871f033925ccf0ff2b740725ae915 upstream. When a module is first loaded and its function ip records are added to the ftrace list of functions to modify, they are set to DISABLED, as their text is still in a read only state. When the module is fully loaded, and can be updated, the flag is cleared, and if their's any functions that should be tracing them, it is updated at that moment. But there's several locations that do record accounting and should ignore records that are marked as disabled, or they can cause issues. Alexei already fixed one location, but others need to be addressed. Fixes: b7ffffbb46f2 "ftrace: Add infrastructure for delayed enabling of module functions" Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--kernel/trace/ftrace.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index fb26c78309aa..b1d7f1b5e791 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1856,6 +1856,10 @@ static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
/* Update rec->flags */
do_for_each_ftrace_rec(pg, rec) {
+
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
/* We need to update only differences of filter_hash */
in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
@@ -1878,6 +1882,10 @@ rollback:
/* Roll back what we did above */
do_for_each_ftrace_rec(pg, rec) {
+
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
if (rec == end)
goto err_out;
@@ -2391,6 +2399,10 @@ void __weak ftrace_replace_code(int enable)
return;
do_for_each_ftrace_rec(pg, rec) {
+
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
failed = __ftrace_replace_code(rec, enable);
if (failed) {
ftrace_bug(failed, rec);
@@ -3592,6 +3604,10 @@ match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
goto out_unlock;
do_for_each_ftrace_rec(pg, rec) {
+
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
ret = enter_record(hash, rec, clear_filter);
if (ret < 0) {
@@ -3787,6 +3803,9 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
do_for_each_ftrace_rec(pg, rec) {
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
if (!ftrace_match_record(rec, &func_g, NULL, 0))
continue;
@@ -4679,6 +4698,9 @@ ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer)
do_for_each_ftrace_rec(pg, rec) {
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
if (ftrace_match_record(rec, &func_g, NULL, 0)) {
/* if it is in the array */
exists = false;